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THE ELEMENTS 
 
 OF 
 
 RAILROAD ENGINEERING 
 
 Prepared for Students of 
 
 The International Correspondence Schools 
 
 SCRANTON, PA. 
 
 Volume II 
 
 SURVEYING RAILROAD LOCATION 
 
 LAND SURVEYING RAILROAD CONSTRUCTION 
 MAPPING TRACK WORK 
 
 RAILROAD STRUCTURES 
 
 WITH PRACTICAL QIJESTIONS AND EXAMPLES 
 
 First Edition 
 
 SCRANTON 
 
 THE COLLIERY ENGINEER CO. 
 1897 
 
 967 
 
V. ^ 
 
 ) I /. t I M 
 
 Copyright, 1897, by The Colliery Engineer Company. 
 
 Surveying : Copyright, 1895, by The Colliery ENGINEER Company. 
 Land Surveying : Copyright, 1895, by The Colliery Engineer Company. 
 Mapping : Copyright, 18i)5, by The Colliery Engineer Company. 
 Railroad Location : Copyright, 1895, by The COLLIERY ENGINEER Company. 
 Railroad Construction : Copyright, 1895, by The COLLIERY ENGINEER Company. 
 Track Work : Copyright, 1896, by The COLLIERY ENGINEER COMPANY. 
 Railroad Structures : Copyright, 1896, by The COLLIERY Engineer Company. 
 
 BURR PRINTING HOUSE, 
 
 FRANKFORT AND JACOB STREETS, 
 
 NEW YORK. 
 
CONTENTS. 
 
 Surveying. page 
 
 Geometrical Principles, GOl 
 
 Compass Surveying, 605 
 
 Transit Surveying, - (J2l 
 
 Triangulation, - - 634 
 
 Curves, - - - - 639 
 
 Leveling, 655 
 
 Topographical Surveying, - - . . . 673 
 
 Indirect Leveling, - - • 682 
 
 Hydrographic Surveying, 690 
 
 Land Surveying. 
 
 United States System, - - - - . _ 693 
 
 Areas, 714 
 
 Latitudes and Departures, 717 
 
 Town Sites and Subdivisions, - . . . 733 
 
 Mapping. 
 
 Introduction, - 74I 
 
 Platting Angles, 74I, 748 
 
 Map of Railroad Location, 766 
 
 Topographical Drawing, 776 
 
 Contours and Slopes, - . . ... 779 
 
 Conventional Signs, 739 
 
 Topographical Maps, 792 
 
 Map of Village, 799 
 
 Railroad Location. 
 
 Introduction, . 313 
 
 Reconnaissance, <J> 8I5 
 
 157140 
 
iv CONTENTS. 
 
 Railroad Location — continued. page 
 
 Field Work, 823 
 
 Problems in Location, -..-.. 832 
 
 Specifications for Grading and Bridging, - - 800 
 
 Railroad Construction. 
 
 The Engineer Corps, ..... - - 869 
 
 Cross-Sectioning, ...... 870 
 
 Culverts, - - - 878 
 
 Retaining Walls, - 899 
 
 Excavation, - - 912 
 
 Tunnel Work, 935 
 
 Protection Work, 966 
 
 Routine Work, 970 
 
 Bridge Work, -....-. 978 
 
 Pile Work, 1002 
 
 Estimates, 1017 
 
 Track Work. 
 
 Track Laying, 1029 
 
 Track Joints, 1036 
 
 Rails, 1038 
 
 Expansion and Contraction, .... 1043 
 
 Spiking Rails, 1045 
 
 Surfacing Track, 1048 
 
 Drainage, 1052 
 
 Care and Maintenance of Track, . . . 1058 
 
 Curved Track, 1087 
 
 Frogs and Switches, 1102 
 
 Yards and Terminals, 1145 
 
 General Instructions, . .... 1148 
 
 Railroad Structures. 
 
 Wooden Trestles, 1103 
 
 Framed Bents, 1177 
 
 Floor System, 1186 
 
 Bracing, ' 1195 
 
 Iron Details, - - 1198 
 
CONTENTS. V 
 
 Railroad Structures — cotitinued. 
 
 Connection of Trestle with Embankment — Pro- page 
 
 tection Against Accidents, - - - . 1207 
 
 Field Engineering and Erecting, - - - 1211 
 
 vSpecifications for Wooden Trestles, ... 1213 
 
 Bills of Materials, Records, and Maintenance, - 1334 
 
 Standard Trestle Plans, 1230 
 
 Simple Wooden Truss Bridges, - - - - 1246 
 
 Water Stations, - - - - - - - 1374 
 
 Coaling Stations, 1381 
 
 Turntables, 1385 
 
 Questions and Examples. 
 
 Surveying, - - - Questions 014-705 1397 
 
 Land Surveying, - - Questions 706-755 1309 
 
 Railroad Location, - - Questions 756-813 1315 
 
 Railroad Construction, - Questions 813-873 1331 
 
 Railroad Construction, - Questions 873-946 1337 
 
 Track Work, - - - Questions 947-1016 1333 
 
 Railroad Structures, - Questions 1017-1083 1339 
 
SURVEYING. 
 
 GEOMETRY. 
 
 1 180. If two triangles have two sides and the included 
 angle of the one equal to two sides and the included angle 
 of the other, the triangles are 
 equal in all their parts. Thus, 
 in the two triangles ABC 
 and D E F, Fig. 236, if the 
 side A B is equal to the side 
 
 D E ; the side B C to the side ^ \ ^ ^ p 
 
 E F, and the angle B to the fig. 236. 
 
 angle E, the triangles are equal in every respect. 
 
 1181. If a straight line, A B, Fig. 237, intersects two 
 parallel straight lines, C D and E F, it is called a secant 
 
 with respect to them, and the eight 
 angles formed about the points of in- 
 tersection have different names applied 
 to them with respect to each other, as 
 follows : 
 
 First — Interior angles on the 
 
 same side are those which lie on the 
 
 Fig. 237, same side of the secant and within the 
 
 other two lines. Thus, in Fig. 237, H G D 2Lnd G H F 2ive 
 
 interior angles on the same side. 
 
 Second — Exterior angles on the same side are those 
 which lie on the same side of the secant but ivithout the 
 other two lines. Thus, A G D a^nd F H B 2Lxe exterior 
 angles on the same side. 
 
 Third — Alternate interior angles are those which lie 
 on opposite sides of the secant and within the other two 
 lines. Thus, C G H and G H Fare alternate interior angles. 
 
602 
 
 SURVEYING. 
 
 Fourth — Alternate exterior uncles are those which 
 lie on opposite sides of the secant and without the other two 
 lines. Thus, A G C and F H B2^x% alternate exterior angles. 
 
 Fifth — Opposite exterior and interior antcles are 
 
 those which lie on the same side of the secant, the one within 
 and the other without the other two lines. Thus, A G D 
 and G H F are opposite exterior and interior angles. 
 
 1182. If a straight line intersects two parallel lines, 
 the sum of the interior angles on the same side is equal to 
 two right angles, and the sum of the exterior angles on the 
 same side is also equal to two right angles. Thus, in Fig. 
 237, the interior angles D G H and F H G are together 
 equal to two right angles, and the exterior angles D G A 
 and F H B are together equal to two right angles. 
 
 1183. If a line intersects two parallel straight lines, 
 the alternate interior angles are equal to each other, and 
 the alternate exterior angles are also equal to each other. 
 Thus, in Fig. 237, the angle C G H \s equal to F H G, and 
 angle C G A \?, equal to F H B. 
 
 1184. The complement of an angle is the difference 
 
 E 
 
 B 
 
 FlO. 238. 
 
 between that angle and a right angle. 
 Thus, in Fig. 238, A B E is the comple- 
 ment oi D B E. 
 
 -D 1185. The supplement of an 
 
 angle is the difference between that 
 angle and two right angles. Thus, C B E is the supplement 
 oiDB E. 
 
 1 186. In any triangle, a line drawn 
 parallel to one of the sides divides the 
 other sides proportionally. Thus, in the 
 triangle ABC, Fig. 239, the line D E 
 drawn parallel to B C divides the sides 
 A B and A C proportionally ; that is, 
 
 A B \ A D\\ A C \ A E; 
 
 A D '. D B\: A E : E C, and 
 
 A B : D B :: A C : E C. KiG.a:>i.. 
 
SURVEYING. 603 
 
 « 
 
 1 1 87. Polygons are similar when they are mutually 
 
 equiangular and have their homologous sides proportional. 
 
 In similar polygons, any points, lines, or angles similarly 
 situated in each are called homologous. The ratio of a 
 side of one polygon to its homologous side in another is 
 called the ratio of similitude of the polygons. 
 
 1188. Triangles which are mutually equiangular are 
 similar, and their areas are to each other as the squares of 
 their homologous sides. 
 
 Thus, in the triangles 
 A B C ?ind.D E F, Fig. 240, 
 if the angle A is equal to the 
 angle D\ the angle B to the 
 
 angle E, and the angle C to B^ ^CE^ ^F 
 
 the angle F, the triangles are Fig. 24o. 
 
 similar, and their areas are to each other as the squares of 
 
 their homologous sides. 
 
 For example, if B C = ^0 feet, EF=oO feet, and the 
 area of the triangle A B C = 1,G00 sq. ft., then 
 80* : 50' :: 1,600 : area oi D E F, or 
 6,400 : 2,500 :: 1,600 : 625 sq. ft. 
 Hence, area oi D E Fis 625 sq. ft. 
 
 1 1 89. The areas of similar polygons are to each other 
 as the squares of their homologous sides. 
 
 Thus, if the area of a regular hexagon with a side of 10 
 inches is 259.809 sq. in., the area of a similar hexagon whose 
 side is 15 inches may be found as follows: 
 
 10" : 15'' :: 259.809 : area required, or 
 100 : 225 :: 259.809 : 584.57 sq. in. 
 
 1190. The circumferences of circles are to each other 
 as their diameters, and their areas are to each other as the 
 squares of their diameters. 
 
 Thus, if the circumference of a circle 12 inches in diam- 
 eter is 37.7 inches, the circumference of a circle of 18 inches 
 diameter may be found by proportion. Thus, 
 
 12 : 18 :: 37.7 : 56.55 in., the circumference required. 
 
G04 
 
 SURVEYING. 
 
 Again, if the area of a circle of 12 inches diameter is 
 113.098 sq. in., the area of a circle of 18 inches diameter 
 may be found as follows: 
 
 12' : 18' :: 113.098 : area required, or 
 144 : 324 :: 113.098 :, 254.47 sq. in. 
 
 1191. An angle formed by a tangent and a chord 
 meeting at the point of contact is 
 measured by half the included arc. 
 
 Thus, in Fig. 241, the angle A C D 
 formed by the meeting of the tangent 
 A B and the chord C D '\s measured 
 by half the arc C E D. Similarly, the 
 angle B C D \s measured by half the 
 arc C D. 
 
 1192. Two tangents to a circle drawn from any point 
 are equal, and if a chord be drawn joining 
 these tangent points, the angles between 
 the chord and the tangents are equal. 
 
 Thus, in Fig. 242, the two tangents 
 A B and A C drawn to the circle from 
 the point A are equal, and the angles 
 ABC and A C B, formed by the chord 
 and tangents, are equal to each other. 
 
 1 1 93. In similar circles equal chords 
 subtend equal angles at the center and 
 also at the circumference. fig. 242. 
 
 Thus, in Fig. 243, the angles A O B, B O C, 2.nA C O D 
 subtended by the equal chords A B, 
 B C, and C D are equal to each 
 other. 
 
 Again, the angles B A C and 
 CAD are also equal to each 
 other. 
 
 1194. In Fig 
 be any triangle, 
 sides, as A C, is 
 
 Fig. 243. 
 
 244, let A B C 
 If one of the 
 prolonged, the 
 angle BCD- included between the 
 
SURVEYING. 
 
 605 
 
 side thus prolonged and the other side B C of the triangle, 
 which meets A C a.t C, is called an 
 exterior angle. The two remain- 
 ing angles A and B of the triangle, 
 which are opposite to the angle 6', 
 are called opposite interior 
 angles. In any triangle, an ex- 
 terior angle is equal to the sum of 
 the two opposite interior angles ; that ^"^- "^^• 
 
 is, in the above figure, the exterior angle B C D is equal to 
 the sum of the two opposite interior angles, A and B. 
 
 1 195. Problem. — Having given one of the angles of a 
 triangle, one of the including sides, and the difference of 
 ^ the other two sides, to construct 
 
 it. 
 
 Let C, Fig. 245, be the given 
 
 angle, A the given side, and B 
 
 the difference of the other sides. 
 
 Draw D E equal to the given 
 
 side A\ 2X D make the angle 
 
 E D F equal to the given angle (7; 
 
 Fig. 245. on D F lay oK D G equal to the 
 
 given difference B. Join E G. At the middle point // of 
 
 E G erect a perpendicular cutting D Fin K. Draw K E. 
 
 D E K is the required triangle. 
 
 COMPASS SURVEYING. 
 
 1196. The Compass. — The surveyor's compass 
 
 consists of the magnetic needle, the case in which it is en- 
 closed, and the support on which it is placed when ready for 
 use. 
 
 1197. The Magnetic Needle.— The magnetic 
 needle is a slender bar of steel, five or six inches in length, 
 strongly magnetized, and mounted upon a finely pointed 
 pivot on which it freely turns, always pointing in the same 
 
006 
 
 SURVEYING. 
 
 direction, viz. : the north and south line, or, as it is called, 
 the magnetic meridian. 
 
 1198. North and South Ends of Needle.— Owing 
 
 to the earth's attraction, the north end of the needle dips, 
 
 that is, it is drawn downward from a horizontal position, 
 
 while the south end is correspondingly raised. To prevent 
 
 this dipping, several coils of platinum wire are wound 
 
 _,, ^. „,. around the south end 
 
 rPlattnum Wire. . , ,, , _. 
 
 — ■ "^ of the needle (see Pig. 
 
 246), keeping it per- 
 fectly balanced upon 
 its pivot and permit- 
 These coils of wire at 
 the north end and 
 
 \Pivot. 
 
 Fig. 246. 
 
 ting entire freedom of movement 
 once indicate to the observer which is 
 which is the south end of the needle. 
 
 1199., The Sights. — At either end of a line passing 
 through the needle pivot is a sight, which consists of an 
 upright bar of brass A and B. (See Fig. 247.) Narrow 
 
 Fig. 247. 
 
 vertical slits, with holes at their top and bottom, divide this 
 bar, as shown at C and D. These arrangements enable 
 the observer to train the line of sight upon any desired 
 object. 
 
SURVEYING. 
 
 607 
 
 1 200. The Divided Circle. — The compass box con- 
 tains a graduated circle divided to half degrees, at the 
 center of which is the pivot supporting the needle. The 
 degrees are numbered from 0° to 90° both ways from the 
 points where a line drawn through the slits would cut the 
 circle. 
 
 1201. Lettering. — The lettering of the surveyor's 
 compass is at first confusing to those learning its use. A 
 person standing with his back to the south and facing the 
 north will have the east on his right hand and the west 
 on his left. These latter directions, viz., the east and. 
 the west, are reversed in the lettering of the compass. 
 The reasons for this apparent error are explained in the 
 following figures: 
 
 Fig. 248. 
 
 Fig. 249. 
 
 Suppose the needle and compass are pointing due north 
 and south in the direction of the line A B, as shown in 
 Fig. 248, and the line of survey changes its direction 45° to 
 the right, or east. The magnetic needle will remain motion- 
 less, while the sights and the circle to which they are fast- 
 ened will move until the sights point in the direction C D, 
 Fig. 240, and, as the north end of the compass is ahead, the 
 needle will read N 45° E, which is the true direction being 
 run. If, however, the east and west points of the compass 
 were the actual magnetic directions, i. e. , the right hand 
 east and the left hand west, the direction of the line C D 
 
608 SURVEYING. 
 
 would have read N 45° W, which would be the reverse of 
 the actual direction. 
 
 1202. Levels. — On the compass plate are two small 
 spirit levels F and G. (See Fig. 247.) They consist of 
 glass tubes, curved slightly upwards and nearly filled 
 with alcohol, leaving a small bubble of air in them. One 
 of these tubes, /% is in the line of sight, the other, C, 
 is at right angles to it. Their object is to enable the 
 observer to place the compass in a perfectly horizontal 
 position. This is done by so moving the compass as 
 to bring the air bubbles to the centers of the tubes. To 
 prove these bubbles to be in adjustment, proceed as fol- 
 lows: Having brought the bubbles to the centers of the 
 tubes, revolve the compass through 180° or one-half of 
 an entire revolution. If the bubbles remain in the cen- 
 ters of the tubes, they are in adjustment. If they do 
 not so remain, bring them half way back to the middle 
 of the tubes by means of small screws attached to the 
 tubes, and the remainder of the way by moving the plate 
 in the ordinary way, repeating the operation until the 
 bubbles remain in the center of the tubes in every position 
 of the compass. 
 
 1 203. The Tripod. — The compass is usually supported 
 by a single standard, shod with steel, and called a Jacob's 
 Staff. A more perfect support, called a tripod, consists 
 of three legs shod with steel and connected at the top so as 
 to move freely. Both Jacob's Staff and tripod are connected 
 with the compass by means of a ball and socket joint, which 
 permits free movement in all directions. 
 
 1204. Defects of the Compass. — The compass is 
 not intended for work requiring great accuracy. The direc- 
 tion to which the needle points can not be read with pre- 
 cision, and the perfect freedom of movement of the needle 
 may be prevented by local attraction or by particles of dust 
 adhering to the pivot. An inaccuracy of one-quarter of a 
 degree in reading an angle, i. e., the amount of change in 
 
SURVEYING. 609 
 
 the direction of two lines, will cause them to separate from 
 each other If feet in a distance of 400 feet. 
 
 Suppose the line A B, Fig. 250, is due east and west, and 
 the line B C, which is an actual boundary, has a true direc- 
 tion of N 85° E, and suppose the surveyor reads the 
 directions ^ 6^ as N 84° 45' E. Let i? C = 400 feet, then, 
 the point C, when mapped, will take the position C\ which is 
 If feet to the left of C where it should be. Another defect 
 of the compass lies in the fact that the magnetic needle does 
 
 C 
 
 A B -—===405*^""^ l^fJ^ 
 
 Fig. 25e. 
 
 not always point in the same direction. This direction some- 
 times changes between sunrise and noon to the amount of 
 one-quarter of a degree. Frequently its direction is changed 
 by local influence. A piece of iron on the surface of the 
 ground or a mass of iron ore beneath are frequent disturbing 
 influences. 
 
 1 205. Taking Bearings. — The bearing of a line is 
 the angle which it makes with the direction of the magnetic 
 needle. By the course of a line we mean its length and its 
 bearing taken together. To take the bearing of a line, set 
 the compass directly over a point of it, at one extremity, if 
 possible. This may be done by means of a plumb bob sus- 
 pended from the compass, or, if the compass be mounted on 
 a. Jacob's Staff, by firmly planting the staff directly on the 
 line. Then, by means of the air bubbles, bring the compass 
 to a perfectly level position. Let a flagman hold a rod care- 
 fully plumbed at another point of the line, preferably the 
 other extremity of it, if he can be distinctly seen. Direct 
 the sights upon this rod and as near the bottom of it as pos- 
 sible. Always keep the same end of the compass ahead; 
 the north end is preferable, as it is readily distinguished by 
 some conspicuous mark, usually a '■'■ fleur de lis," and always 
 read the same end of the needle, that is, the north end 
 of the needle if the nor th point of the compass is ahead, 
 
OlO 
 
 SURVEYING. 
 
 and vice versa. Before reading the angle, see that the eye 
 is in the direct line of the needle so as to avoid error 
 which would otherwise result from parallax, or apparent 
 change of the position of the needle, due to looking at it 
 obliquely. 
 
 The angle is read and recorded by noting, first, whether 
 the N OT S point of the compass is nearest the end of the 
 J. needle being read; second, the 
 y number of degrees to which it 
 points, and third, the letter E or 
 W nearest the end of the needle 
 being read. 
 
 Let A B, in Fig. 251, be the 
 direction of the magnetic needle, 
 B being at the north end. Let 
 the sights of the compass be 
 directed along the line C D. The 
 north point of the compass will be 
 seen to be nearest the north end 
 of the needle which is to be read. The needle which 
 has remained stationary while the sights were being 
 turned to C Z>, now points to 45° between the N and E 
 points, and the angle is read north forty-five degrees east 
 (N45° E). 
 
 1 206. Backsights. — A sure test of the accuracy of a 
 bearing is to set up the compass at the other end of the line, 
 i. e., the end first sighted to, and sight to a rod set up at the 
 starting point. This process is called backslKtitliiK. If 
 the second bearing is the same as the first, the reading is 
 correct. If it is not the same, it shows that there is some 
 disturbing influence at either one or the other end of the 
 line. To determine which of these two bearings is the true 
 one, the compass must be set up at one or more intermediate 
 points, when two or more similar bearings will prove the true 
 one. When a line can not be prolonged by magnetic bearings, 
 on account of local attraction, the true direction is maintained 
 by backsighting. 
 
SURVEYING, (311 
 
 1 207. Declination of tlie Needle. — The magnetic 
 meridian is the direction of the magnetic needle. The true 
 meridian is a true north and south line, which, 
 if produced, would pass through the poles of the 
 earth. The declination of the needle is the 
 angle which the magnetic meridian and the true 
 meridian make with each other. 
 
 In Fig. 252, let N S he the true meridian for 
 any given place, and iV 5* the magnetic meridian. 
 The angle NA iV* is the declination of the needle 
 for that place. 
 
 1 208. The Polar Star. — There is a star in 
 the northern hemisphere known as the North Star 
 or Polaris. It is the extreme star in the row or 
 line of stars forming what is commonly called the ^ 
 handle of the "Little Dipper." This star very ^ 
 nearly coincides with the true north point or ^"^- '^^• 
 pole, being removed only 1^° from it. It revolves about the 
 true pole, and twice in each revolution it is exactly in the true 
 ^--^^---^ meridian ; that is, in a vertical plane passing 
 through the true pole P. See Fig. 253. One 
 may know when the North Star is in the true 
 meridian from the position of another star. 
 This other star is in the handle of the " Big 
 Fig. 253. Dipper, "or Ursa Major, the one nearest the 
 bowl of the dipper, and is called Alioth. When the North 
 Star is in the true meridian, Alioth will be found directly 
 below it. 
 
 TO DETERMINE A TRUE MERIDIAN. 
 
 1 209. By Observations of the North Star.— The 
 
 time at which the North Star passes the meridian above the 
 
 pole for every tenth day of the year is given in published 
 
 tables, but those occurring in the day time are, of course, 
 
 of no- value with ordinary instruments. The following 
 
 dates are available in almost every latitude of the United 
 
 States: 
 J' 
 
 O 
 
012 
 
 SURVEYING. 
 
 TIME OF NORTH STAR PASSING THE 
 MERIDIAN. 
 
 Months. 
 
 1st Day. 
 
 11th Day. 
 
 21st Day. 
 
 January 
 
 August 
 
 September 
 
 October 
 
 November 
 
 December 
 
 6:30 P. M. 
 
 4:33 A. M. 
 
 2:31 A. M. 
 12:34 A. M. 
 10:28 P. M. 
 
 8:30 P. M. 
 
 5:51 P. M. 
 3:53 A. M. 
 1 :52 A. M. 
 11:50 P. M. 
 9:48 P. M. 
 7 :50 P. M. 
 
 5:11 P. M. 
 3:14 A. M. 
 1:12 A. M. 
 11:11 P. M. 
 9:09 P. M. 
 7:11 P. M. 
 
 Note from the table the time of passing the meridian, 
 and, also, that it is the upper transit, i. e., above the pole. 
 Select a suitable spot for permanently establishing the 
 meridian line, and set up the transit and sight to Polaris, 
 following it by moving the cross-hairs with the tangent 
 screw. When it is exactly in line with Alioth, the line 
 of sight will be in the true meridian. Points should be fixed 
 immediately, a lamp being used to illuminate the cross- 
 hairs. 
 
 1210. Changes in Magnetic Declination. — The 
 
 magnetic declination is not fixed for any place, but con- 
 stantly varies, its variations, however, being confined within 
 fixed limits. 
 
 1211. To Correct Magnetic Bearings. — The dec- 
 lination at any place being known, the magnetic bearings 
 may readily be reduced to true bearings. 
 
 In the Northeastern States, the declination is west; in 
 the Western and Southern States, it is east ; hence, the true 
 bearing of a line in a Northeastern State, whose magnetic 
 bearing is N W or S E, will be the sum of the magnetic 
 bearing and the declination. If the magnetic bearing is 
 N E or S W, the true bearing will be the difference of 
 the magnetic bearing and the declination. 
 
SURVEYING. 
 
 613 
 
 EXAMPLES FOR PRACTICE. 
 
 1 212. Supposing the declination to be 7° west, what'' will be the 
 
 true bearings of the following lines 
 Magnetic Bearing. 
 
 (1) N 12° 10' W ? 
 
 (2) N 50° 15' W ? 
 
 (3) S ir 15' E ? 
 
 (4) S 38° 10' E ? 
 
 (5) N 50° 20' E ? 
 
 (6) S 20° 25' W ? 
 
 (7) N 87° 30' W ? 
 
 (8) N 5° 10' E ? 
 
 (9) S 89° 20' E ? 
 (10) S 3° 10' W ? 
 
 Ans. 
 
 True Bearings. 
 
 (1) N 19° 10' W. 
 
 (2) N 57° 15' W. 
 
 (3) S 18° 15' E." 
 
 (4) S 45° 10' E. 
 
 (5) N 43° 20' E. 
 
 (6) S 13° 25' W. 
 
 (7) S 85° 30' W. 
 
 (8) N 1° 50' W. 
 
 (9) N 83° 40' E. 
 L (10) S 3° 50' E. 
 
 1213. By Equal Shadows of the Sun. — On the 
 
 south side of any level surface set up a flag-pole and plumb 
 
 it with a plumb bob. Its horizontal 
 
 projection will be a point as S in Fig. 
 
 254. Two or three hours before noon 
 
 mark the point yi, which is the extremity 
 
 of the shadow cast by the flag-pole. 
 
 Then, describe an arc A B with a radius 
 
 equal to S A, the distance from S to the 
 
 extremity of the shadow. After noon, 
 
 note the moment when the shadow of the flag-pole touches 
 
 another point of the arc, as B. Bisect the arc A B at N. 
 
 The line 5 iV is a true meridian. 
 
 FIELD WORK. 
 1214. The Engineer's Chain. — The engineer's chain 
 is one hundred feet in length, and is composed of one hun- 
 dred links of steel wire, each one foot in length. Both ends 
 of the chain are fitted with brass handles with swivel move- 
 ments, and fitted with nuts for taking up any excess 
 in length resulting from continual stretching. At each 
 interval of ten feet is a brass tag with tally points to indi- 
 cate its distance from the nearest end of the chain. Each 
 tally point counts ten feet. At the middle point of the 
 
614 SURVEYING 
 
 chain, the tag is of oval form to prevent confusion in reading 
 the chain. 
 
 1215. l>anger of Error. — There is much greater 
 danger of error in reading the chain than in reading bear- 
 ings. The danger arises from the fact that the compassman 
 is usually one of experience, who knows the liability of error, 
 and hence the necessity for care, while chainmen are often 
 inexperienced, and, unfortunately, often careless. 
 
 1216. Keeping Chainmen in Line. — When the 
 direction of a line has been given by setting up a flag, it be- 
 comes the business of the hind chainman or follower to keep 
 the measurement on a straight line. The head chainman 
 carries a flag which he moves to right or left, at the di- 
 rection of the hind chainman, until it is in range with the 
 flag towards which the compass is sighted, and this process 
 is repeated at each chain measurement. 
 
 In railroad surveying, the line is divided into stations, 
 which are one hundred feet or one chain apart. At each 
 station a stake is driven and marked with a number corre- 
 sponding to the number of chains which the station is distant 
 from the starting point, which is numbered 0. When the 
 end of a course falls between regular stations, it is called a 
 sub-station, and the stake is marked by the number of the 
 immediately preceding station plus the number of feet from 
 it to the end of the course. 
 
 The line A B, in Fig. 255, is 650 feet in length. The 
 starting point A is numbered 0\ each chain or one hundred 
 
 1 2 3 4 5 6 6 +50 
 
 ^ Pig. 255. -^ 
 
 feet is marked by a stake with numbers in regular notation. 
 The point B, which is fifty feet from station 6, is marked 
 6 + 50. 
 
 1217. — The Compass in Railroad Surveys. — The 
 
 compass is of great value in running preliminary railroad 
 lines, where local attraction is absent or very slight. The 
 numerous delays encountered when running by backsights, 
 
SURVEYING. 615 
 
 as in transit work, where all obstacles to the line of sight 
 must be cleared, are largely avoided in the use of the com- 
 pass. The directions of all lines are referred to the mag- 
 netic needle, and, in case of an obstruction, such as a tree or 
 a mass of rock, the compass can be quickly moved to the op- 
 posite side of the obstacle and the line continued without 
 delay. In case the line produced is a foot or two off the true 
 one, // is a parallel to it, and the error is not to be re- 
 garded as affecting the accuracy oi preliminary information. 
 In the case of transit work, an error in the reading of an 
 angle is a cunmlative one, and practically destroys the value 
 of the work. In the early days of railroad building, some 
 lines were surveyed and built with the aid of the compass 
 alone, but in America all location and construction depend 
 for their precision upon the transit. 
 
 1218. Organization of Party. — A well-organized 
 compass party consists of a chief of party, compassman, 
 two chainmen, one flagman, two or more axmen, if the 
 country be thickly wooded, and one stakeman. If possible, 
 provide stakes of light, well-seasoned wood. For preliminary 
 lines where stakes do no permanent service, pine is best. A 
 convenient size is two feet six inches in length by two inches 
 in width and half an inch in thickness. A strong, active 
 stakeman will carry one hundred of these stakes, besides 
 the ax with which to drive them. Provide both chainmen 
 with marking crayons. The best crayon is of red chalk or 
 German kiel. They are bought in a crude state, but a little 
 work will shape them. They make a deep red mark, which 
 will stand exposure for years. Require chainmen to be 
 always provided with crayons. Instances of their forgetful- 
 ness too often occur. Require axmen to keep axes sharp. 
 A dull ax is little better than no ax. Check length of 
 chain with standard steel tape, lengthening or shortening by 
 means explained in Art. 1214. See that the compass is in 
 perfect adjustment. If the line to be surveyed is of consid- 
 erable length, a team of horses and driver with a strong 
 spring wagon should be a part of the outfit. 
 
616 SURVEYING. 
 
 1219. Actual Work. — The party is now prepared 
 
 to move. The compassman sets up the compass at the 
 starting point, which is marked 0. The chief of party 
 goes ahead with the flagman, who carries a rod called 
 a flag. This rod is from eight to twelve feet in length, 
 and is divided into alternate red and white bands, each 
 one foot in length. The flagman sets this flag up at the 
 direction of the chief of party, the compassman sights 
 the instrument to it, and the chainmen commence meas- 
 uring the distance. The head chainman marks the stakes, 
 and should always keep at least ten stakes marked ahead 
 so as to avoid delay while measuring, and to insure con- 
 secutive numbering. Of these he need carry but five, 
 leaving the remaining five with the stakeman. He must 
 also carry a flag eight feet in length, and painted like 
 the one carried by the flagman; this flag is used for "rang- 
 ing in." As soon as the line is indicated by the head flag, 
 the axmen should fall to work clearing whatever obstacles 
 lie in the way of rapid chaining. By a little attention on 
 their own part and occasional direction from the chainmen, 
 they can keep well on line. At each station, and the 
 moment the hind chainman has put the head chainman in 
 
 line, the former should 
 
 ^^ gQ.t ^ carefully note the 
 
 number of the station 
 
 jh;;;^- g^t >, at whlch hc stands and 
 
 call the number to the 
 head chainman who 
 must answer by repeat- 
 mg the number next 
 in notation. Thus, if the hind chainman stands at Station 
 25 he must call " Station 25," and the head chainman must 
 reply "Station 26." The chainmen must be required to 
 hold the chain " taut " while measuring, and in as nearly 
 horizontal a position as possible. When the line of meas- 
 urement rises or falls abruptly, the chainmen must "break 
 the chain," as it is called. The best method of breaking the 
 chain is shown in Fig. 256. 
 
SURVEYING. 617 
 
 Let A B be a. sloping surface lying in tHe line of measure- 
 ment. The point A is at Station 17. Stretchout the chain 
 to its full length and in proper line. The hind chainman 
 will be at Station 17. The head chainman here takes the 
 chain at the 50-foot tag and raises it until it is practically 
 level. The flag he carries for ranging in will serve for a 
 plumb line to mark the 50-foot point on the ground. The 
 hind chainman then calls the number of his station, 17, the 
 head chainman replying 17 + 50. The former then advances 
 to 17 + 50 and holds the middle tag at the point marked by 
 the rod. The head chainman then advances to the other 
 end of the chain and repeats the operation, reaching Station 
 18. When the slope is steep, the chain must be broken into 
 smaller sections. It is good practice for the flagman to 
 carry, besides his flag, a number of light stakes at least 
 eight feet in length and some strips of red flannel for 
 targets. If the view for the compass is open, as soon as 
 the compass is sighted and the flagman has a signal to that 
 effect, he should replace the flag by one of the stakes with 
 a piece of flannel attached and join the chief of party, who, 
 unless the line is to be produced, has gone ahead to select 
 another point for the flag. As soon as the compassman has 
 recorded the bearing of the line, he should take the compass 
 and walk rapidly to the next station, marked either by the 
 flag or target, and, if in full view of the chainmen, remove 
 the station mark and set up the compass and be prepared to 
 take the next bearing the moment it is indicated by the 
 chief of party. As soon as the chainmen reach the com- 
 pass and have "taken the plus" from the last full station, 
 the hind chainman calls out the full station and plus, which 
 the head chainman marks on a fresh stake and which the 
 compassman records as the length of the course run. If the 
 same line is to be continued or "produced," the compass is 
 set at the same bearing as the course just run and the 
 chainmen are lined in by the compassman. 
 
 1220. Example of the Use of the Compass in 
 Railroad Work. — Suppose C A D in Fig. 257 to be a 
 
618 
 
 SURVEYING. 
 
 Bp4H75 
 
 railroad in operation, and that 
 it has been decided to run a 
 compass line from the point A 
 along the valley of the stream 
 X Y to the point B. The 
 bearing of the tangent A I) 
 can not be determined by set- 
 ting up the compass at/i,on 
 account of the attraction of 
 the rails. The direction of 
 this tangent, however, can be 
 obtained by setting up the 
 cortipass at A and sighting to 
 the flag held at D. The point 
 A^ which is the starting point 
 of the line to be run, is 
 marked 0. Producing the line 
 A D 440 feet, the point E is 
 reached, which has been pre- 
 viovisly indicated by the chief 
 of party as a proper place for 
 changing the direction of the 
 line. The compass being set 
 up at E^ the bearing of the 
 line A E, which is the line 
 A D produced, is found by 
 sighting to A^ or, what is 
 preferable, to the point Z>, 
 if that point can be seen. 
 The number of Station E^ 
 viz., 4 + 40, and the bearing 
 
SURVEYING. 619 
 
 of A E are then recorded by the compassman. By this 
 time the chief of party has located the point F^ and the flag 
 is in place for sighting. The axmen, if there is work for 
 them to do, are put in line by the head chainman, clearing 
 only so much as would interfere with rapid chaining. The 
 bearing of the line E F being recorded, the compass is 
 moved quickly to /%. replacing the target left by the flagman, 
 leveled up, and directed toward the point 6", which is either 
 already, or soon will be, located. The chainmen reaching 
 /% its number 11 -|- 20 is recorded by the compassman, and 
 the instrument sighted to G and the work continued as 
 before. 
 
 1221. Form for Keeping Notes. — A plain and con- 
 venient form for compass notes is the following, which is a 
 record of the survey platted in Fig, 257: The first column 
 contains the station numbers, the notation running from the 
 bottom to the top of the page. By such an arrangement, 
 the lengths of the courses are found by subtracting the num- 
 ber of the station of one compass point from the number 
 of the station of the next succeeding compass point. 
 Before commencing the plat, the subtractions are made 
 and the lengths of the courses written in red ink between 
 the station numbers. 
 
 The second column contains the bearings of the lines. 
 The bearing recorded opposite to a station is the bearing of 
 the course between the given station and the one next above. 
 Thus, the bearing recorded opposite Sta. is N 75° 00' W, 
 and is the bearing of the line extending from Sta. to Sta. 
 4-|-40 next above. The length of the course is the differ- 
 ence between and 4 + 40 equal to 440 ft. The bearing 
 recorded opposite to 4 + 40 is N 25° 00' W. It is the bear- 
 ing of the line extending from Sta. 4 + 40 to Sta. 11 -|- 20 
 next above. Its length is found by subtracting 4 + 40 from 
 11 + 20 equal to 680 ft., and so on. 
 
 In the third column, under the head of remarks, are 
 recorded notes of reference, topography, and any informa- 
 tion which may aid in platting or subsequent location. 
 
620 
 
 SURVEYING. 
 
 Station. 
 
 Bearing. 
 
 Remarks. 
 
 
 
 
 
 
 
 47+75 
 
 
 End of line 
 
 35 + 75 
 
 N 25° 40' E 
 
 
 27 + 50 
 
 N 14° 10' E 
 
 
 20+35 
 
 N 2° 30' W 
 
 Woodland 
 
 11 + 20 
 
 N 15° lo: W 
 
 
 4 + 40 
 
 N 25° 00' W 
 
 
 
 
 N 75° 00' W 
 
 Sta. is at P. C. of 14° curve to 
 
 
 
 left at Bellford Sta. O. &P. R. R. 
 
 1 222. Platting. — After a survey has been finished, a 
 drawing is made showing the courses. This drawing is 
 called a plat, and the operation of making the plat from 
 the field notes is called platting. 
 
 Since the direction of every line of a compass survey is 
 referred to the same parallel, viz., the magnetic meridian, 
 the readiest mode of platting such a survey is by the use of 
 the T square and protractor. The lines drawn to a T square 
 are parallel, and in platting take the direction of the mag- 
 netic needle, or meridian. 
 
 The line A B, described in Art. 1 220 and shown in Fig. 
 257, is platted as follows: The arrow shown in the figure 
 gives the direction of the magnetic meridian. A line A L, 
 parallel to this meridian, is drawn through the starting 
 point A, and from A as a. center the line A £, whose direc- 
 tion N 75° 00' W is taken from the field notes kept by the 
 compassman, is laid off with a protractor. The directions 
 west are laid off to the left of the meridian, and those east 
 to the right of the meridian. The course A E, being a 
 northwest course, is laid off to the left of the meridian A L, 
 as shown in the figure. The length of the line A E is then 
 
SURVEYING. 
 
 621 
 
 measured on this line to any convenient scale, usually 300 
 feet to the inch, and a parallel to the magnetic meridian 
 drawn through E^ from which the bearing of the line E F^ 
 viz., N 25° 00' W, is laid off and platted. The remaining 
 courses are platted in the same manner. 
 
 TRANSIT SURVEYING. 
 
 THE INSTRUMENT. 
 1223. The engineer's transit, see Fig. 258, is an 
 instrument in which the telescope stakes the place of the 
 plain sights of the compass, 
 and in which the angles are 
 read to single minutes by 
 the vernier. A level C is 
 attached to the underside 
 of the telescope and a ver- 
 tical arc D is attached to 
 the outside of the left hand 
 standard. A vernier E for 
 reading vertical angles is 
 attached to the telescope 
 axis and adjusted by the 
 tangent screw F. The 
 standards G and G, which 
 support the telescope, are 
 fastened to the upper or 
 vernier plate, as is one of 
 the levels 7/, the other 
 being carried by one of the 
 standards at H' . The com- 
 pass circle A", which is 
 divided like that of the 
 ordinary compass, is also a fig. 258. 
 
 part of the upper plate. The vernier plate covers the lower 
 or divided limb, of which only two small arcs can be seen 
 through the openings where the verniers are placed. A 
 
622 
 
 SURVEYING. 
 
 screw which clamps the vernier plate to the divided limb is 
 
 shown at /'. Slow motion is given to the upper plate by 
 
 -Hi the tangent screw J/, and to the divided limb by 
 
 the screw L. The transit is fastened to the plate 
 
 N by a ball and socket joint, and is leveled by 
 
 means of the screws P, Q, R, and S. It is 
 
 fastened to the tripod 7^ in a variety of ways, 
 
 usually screwed to the tripod, the edge of the 
 
 plate N being milled to aid the operator. The 
 
 transit is brought to center over a point by 
 
 means of a plumb bob which is suspended 
 
 fastened to the lower part of the 
 
 CQ !^^ 
 
 o-H 
 
 t^ 
 
 N$ 
 
 by a loop 
 transit. 
 
 1224. The Telescope. — The telescope is 
 
 a combination of lenses placed in a tube and so 
 arranged according to the laws of optics that the 
 image of any object toward which the telescope 
 is directed shall be formed within the tube by 
 the rays of light coming from the object and 
 ^ bent in passing through the object glass. This 
 o image is magnified by the eye-piece," which is 
 composed of several lenses. Telescopes are of 
 various kinds, some representing the object erect, 
 i. e., in its natural position, others representing 
 the object inverted. 
 
 The telescope shown in Fig. 259 represents the 
 object in an erect position. Rays of light from 
 the object A fall upon the object glass B where 
 they are bent, and, crossing each other, form the 
 image at C in an inverted position. Passing on 
 through the lens D, they are refracted or bent, 
 crossing each other again before reaching the lens 
 at E. Passing through the lens F they form an 
 erect image at G, which is in turn magnified by 
 the eye-piece H. 
 
 1225. The Cross-Hairs.— In order that 
 the line of sight may be precisely brought to 
 
SURVEYING. 
 
 623 
 
 bear upon any point of an object within the field of the 
 telescope, two fine lines called cross-hairs, or cross- 
 Swires, are placed with their intersection at the common 
 focus of the object glass and the eye-piece. The inter- 
 section of these cross-hairs can be seen through the 
 eye-piece, and seems to be in the same position as that of 
 the image of the distant object. 
 
 The line passing through the intersection of the cross- 
 hairs and the optical center of the object glass is called the 
 line of collimation. 
 
 The cross-hairs are fastened to a thick brass ring placed 
 within the telescope and held in position by capstan 
 
 headed screws. Fig. 
 260, let into this ring. 
 They are commonly 
 placed at right angles to 
 each other, the one being 
 vertical and the other 
 horizontal. The ring, 
 together with the cross- 
 hairs, can be moved by 
 the capstan headed 
 screws. The cross-hairs 
 are either of platinum wire, drawn very fine, or spider threads. 
 Platinum wire is best, as it is not affected by changes of 
 temperature. 
 
 Fig. 260. 
 
 1226. Focusing the Telescope. — The movement of 
 the object glass is effected by a milled headed screw U, 
 shown in Fig. 258. This screw moves the object glass out 
 or in, according as the object is nearer or further from the 
 instrument. The eye-piece is focused upon the cross-hairs 
 by a similar screw V. The cross-hairs are not in proper 
 focus until they appear to be a part of the object looked at, 
 showing no movement, however the position of the eye may 
 be changed. 
 
 The telescope is supported upon an axis and so placed that 
 both ends shall be as nearly balanced as possible. The axis 
 
624 SURVEYING. 
 
 rests on upright legs called the standards. The standards 
 are fastened to the upper plate. 
 
 1 227. The Graduated Circle.— This circle is divided 
 into 360 equal parts or degrees, and each degree is further 
 divided into two or three equal parts. If the degree is 
 divided into two equal parts, each part equals 30', and if 
 into three equal parts, each part equals 20'. The degrees 
 number from to 360°, and in most instruments there is an 
 inner graduated circle, which numbers each way from to 
 90°, as on the compass circle. Each tenth degree is num- 
 bered; each fifth degree is indicated by a longer line of 
 division, and each degree by a line longer than its 
 subdivisions. 
 
 1228. Movements. — When the line of sight is to be 
 brought to bear upon a distant object, the observer turns 
 the telescope in the direction of the object by lightly but 
 firmly grasping the upper plate, one hand on either side of 
 the instrument. The eye is ranged along the top of the 
 telescope, which is turned by the hands until it appears to 
 be in the direct line of the object. The eye is then brought 
 to the eye-piece, and the object glass focused upon the ob- 
 ject. The instrument is then clamped, and, by means of 
 either of the tangent screws, the cross-hairs are brought 
 to bear precisely upon any desired point of the object 
 viewed. 
 
 1229. The Levels. — Most of the angles measured by 
 the transit are horizontal angles, but whether horizontal or 
 vertical, before an angle can be measured, the plate carry- 
 ing the graduated circle must be brought to a horizontal 
 position. This is effected by means of two small levels 
 placed on the plate at right angles to each other. Each 
 level consists of a glass tube curved upwards at its middle 
 and nearly filled with alcohol, leaving only space for a 
 bubble of air. They are so placed that when the air bubbles 
 are exactly in the middle of the tubes, the plate upon which 
 they rest will be in a level position. The leveling is 
 
SURVEYING. 625 
 
 performed by means of four leveling screws. They have 
 milled heads and are arranged in pairs, the line passing 
 through one pair being at right angles to that passing 
 through the other pair. 
 
 1 230. To Level the Instrument. — Loosen the lower 
 clamp and bring one of the bubble tubes into a parallel to a 
 plane passing through a pair of opposite screws. By turn- 
 ing these screws, the air bubble can be brought exactly to 
 the center of the tube. As the tubes are at right angles to 
 each other, the putting of one in position for leveling ad- 
 justs the other for leveling also, and having leveled one tube 
 with one pair of screws, the other tube is leveled with the 
 other pair. 
 
 1231. The Vernier. — A vernier is a contrivance for 
 measuring smaller portions of space than those into which 
 
 9\0 
 
 7\0 
 
 Fig. 261. 
 
 a line is actually divided. The divided circle of the transit 
 is graduated to half degrees, or 30'. The graduations on the 
 verniers run in both directions from its zero mark, making 
 two distinct verniers, one for reading angles turned to the 
 right, and the other for reading those turned to the left. 
 Each vernier is divided into 30 equal spaces, which are to- 
 gether equivalent to 29 spaces on the divided circle ; hence, 
 each space on the vernier is equal to 29', and the vernier is 
 described as reading to minutes. In reading the vernier, the 
 observer should first note in which direction the graduations 
 of the divided circle run. In Fig. 301 the graduations in- 
 crease from left to right and extend from 57° to 91°. Next 
 he should note the point where the zero mark of the vernier 
 comes on the divided circle. In Fig. 201, the zero mark 
 comes between 7-4° and 74^°. Now, as the circle graduations 
 
626 
 
 SURVEYING. 
 
 read from left to right, we read the right-hand vernier 
 and find that the 23d graduation on the vernier coincides 
 with a graduation on the divided circle, and the vernier 
 reads 23', which we add to 74°, making a reading of 74° 23', 
 an angle to the left. In Fig. 262 the graduations on the 
 circle increase from right to left, and we accordingly read 
 the left-hand vernier. The zero mark of the vernier comes 
 between 67^ and 68°. Reading the vernier, we find that the 
 
 uiu 
 
 7\0 ^*" 
 
 Fig. 262. 
 
 13th graduation on the vernier coincides with a graduation 
 on the circle, and the vernier reads 13'. Accordingly, we 
 add to 67^°, the vernier reading of 13', making a total read- 
 ing of 67° 43', an angle to the right. 
 
 ADJUSTING THE TRANSIT. 
 
 1232. The constant use of an instrument tends to dis- 
 arrange some of its parts, which detracts from the accuracy 
 of its work, without in any way injuring the instrument 
 itself. 
 
 The correction of this disarrangement of parts is called 
 making the adjustments. 
 
 The transit, when leveled up, will, if in adjustment, fulfil 
 the following conditions, viz. : 
 
 1. It will maintain a perfectly horizontal position 
 during an entire revolution. 
 
 2. The line of sight, when directed in opposite direc- 
 tions, will be in the same straight line ; and 
 
 3. The line of sight will revolve in a vertical plane 
 perpendicular to the horizontal plane of revolution. 
 
SURVEYING. 627 
 
 The adjustments should be made in the order of these 
 three conditions. The best time of the day for making the 
 adjustments, especially in the summer season, is the early 
 morning, before the air has become heated and the sun 
 dazzling. 
 
 1233. First Adjustment. — Secure, if possible, an 
 open space where a clear sight may be had for at least 400 
 feet in both directions from the transit. Plant the feet of 
 the tripod firmly in the ground, and then bring the plate to 
 a horizontal position with the leveling screws. Next turn 
 the vernier plate half way around, i. e., revolve it through 
 an angle of 180°. If the bubbles are in adjustment they 
 will remain stationary in the centers of the tubes. If they 
 do not remain so, but run to either end, bring them half way 
 back to the middle of the tubes by means of the capstan 
 headed screws, attached to the tubes, and the rest of the way 
 back by the leveling screws. Then, revolve them again 
 through 180°. Sometimes this adjustment is made by one 
 trial, but it is usually necessary to repeat the operation. 
 
 1 234. Second Adjustment. — To cause the line of col- 
 limation to revolve in a plane : 
 
 Fig. 263. 
 
 Measure from A, where the instrument is stationed (see 
 *Fig. 203), 400 feet to the point B, where a pin (or tack, if 
 it can be seen) is fixed. 
 
 Carefully direct the line of sight to this point, and re- 
 verse the telescope, i. e., ttirn it on its axis until it points 
 in the opposite direction. If the line of collimation is "in 
 adjustment," a pin set 400 feet from A, on the opposite side 
 of the instrument from j5, will be at /^and in the same line 
 2i% A B\ \i '\X. is not in adjustment, the pin will be on one 
 side of /% as at D. Turn the vernier plate half way around, 
 that is, through 180°, and direct the line of sight again to B. 
 
628 SURVEYING. 
 
 Reverse the telescope, and the pin will be at C. Carefully 
 measure the distance C D, and at E, one-fourth of the dis- 
 tance from C to D, set the pin. Move the cross-hairs by 
 means of the capstan headed screws until the vertical hair 
 shall exactly cover the pin at E, being careful to move them 
 in the opposite direction from that in which it would appear 
 they should move. This movement having been made and 
 the telescope reversed, the line of sight will not be at the 
 point y>, but at G, a distance from B equal to C E. Again 
 sight to B^ and, reversing, the pin will be at /% in the same 
 line as A B. It may be necessary to repeat the operation 
 to secure an exact adjustment. If so, take a new set of 
 points, a few inches removed from those first used, to avoid 
 confusion. 
 
 1235. Third Adjustment. — To cause the line of 
 collimation to revolve in a vertical plane: 
 
 Suspend a plumb bob at as high an elevation as can be 
 A readily found; direct the line of sight to the 
 upper end of this line and then, revolving the 
 telescope slowly downwards, see if the intersec- 
 tion of the cross-hairs closely follows this line 
 throughout its length. If it does follow it, the 
 line of collimation revolves in a vertical plane. 
 If it does not, the adjustment may be made as 
 follows: Take a point A^ in Fig. 204, on a church 
 spire or some other high object, and sight care- 
 fully to it. Depress the telescope until a pin can 
 be set in the ground at its base, as at B. Loosen 
 the clamp and turn the plate through 180° with- 
 out touching the telescope. Clamp the instru- 
 B^—i^-^C ment and sight again to the high point A. Again 
 Fig. 264. depress the telescope and set another pin, which 
 it will be found is at some distance from B^ as at C. The 
 vertical plane is the line A D, and it will be seen that the 
 error is doubled. The adjustment is made by raising or 
 lowering one end of the telescope axis by means of a small 
 screw placed in the standard for that purpose. 
 
SURVEYING. 629 
 
 DIRECTIONS FOR USING THE TRANSIT. 
 
 1 236. Care of the Transit. — The transit, though it 
 will bear a lifetime of legitimate service, will not stand 
 neglect or banging. The bearings are delicate and easily 
 marred by particles of dust or sudden blows. Moisture 
 clouds the lenses, and, when combined with dust, is doubly 
 injurious. Little advantage is gained from working in the 
 rain, and, unless the stress of work requires it, both instru- 
 ment and men are better off under cover. If the instru- 
 ments should encounter a wetting, carefully wipe the object 
 glass, eye-piece, and verniers with a piece of chamois skin, 
 as moisture soon clouds them so as to prevent further work. 
 As soon as the party returns to office or camp, complete the 
 drying process by thoroughly rubbing with a piece of 
 chamois skin, which every engineering party should carry. 
 When a party rides to and from work, the instruments 
 should be carried in their cases, and they should always be 
 kept in their cases when in the office. The common cus- 
 tom of leaving an instrument on its tripod and standing on 
 a board floor can not be too severely condemned. 
 
 1237. Setting Up the Instrument. — As much of 
 the work of an engineering party is suspended while the 
 instrument is being set up, it is highly important to acquire 
 facility in setting it up. The following suggestions will be 
 of use, although practice alone will make one expert. 
 
 In setting up a transit, three preliminary conditions 
 should be met as nearly as possible, viz. : 
 
 1. The tripod feet should be firmly planted. 
 
 2. The plate on which the leveling screws rest should be 
 level; and 
 
 3. The plumb bob should be directly over the given 
 point. 
 
 The third condition must be met to a nicety, and this is 
 rendered comparatively easy by means of a " shifting head " 
 with which most modern transits are provided. When these 
 three conditions are approximately met, the completion of 
 the operation is quickly performed with the leveling screws. 
 
630 SURVEYING. 
 
 1 238. How to Prolong a Straight Line.— Let A B, 
 in Fig. 265, be a straight line, and it is required to prolong 
 or produce it 400 feet to C. 
 
 400' 
 
 Fig. 265. 
 
 The line can be prolonged in two ways — by means of 
 foresiglit and backsight. 
 
 1. By foresight, set up the transit at A and sight to B ; let 
 the chainman measure 400 feet from B in the direction in 
 which the line is to be prolonged. Then, by means of signals, 
 move the flag to right or left until the vertical cross-hair 
 shall exactly divide the flag held at C. Then, the line B C 
 will be the prolongation of the line A B. 
 
 2. By backsight, set the transit at B and sight to A. 
 Reverse the telescope, and, having measured 400 feet from 
 B in the opposite direction from A, set the flag at C, then 
 the line B C will be the line A B produced. 
 
 1 239. Double Centers. — In prolonging lines, a device 
 known as double centering is sometimes used. It is un- 
 necessary when using an instrument that is in proper 
 adjustment, but it is a good check, and a knowledge of the 
 method is valuable. 
 
 Let A B, in Fig. 2G6, be a given line which it is re- 
 quired to produce 1,000 feet, ^et up the transit at B; 
 ^ g 500\ P SOO* O 
 
 Fig. 266. 
 
 backsight to A, and reverse the instrument. Set a point C 
 600 feet from B. Unclamp the upper plate and revolve the 
 telescope through 180°, backsighting again to A. Reverse 
 the telescope. If the line of sight does not come at C, then 
 the point C is not in line with the points A and B, and the 
 line of sight will be at some point, as/), on the opposite side 
 of the true line. Measure the space C D and mark its mid- 
 dle point E. The point E will be in the prolongation of the 
 
SURVEYING. 631 
 
 line A B. Move the transit to E, and, backsighting to B^ 
 determine the point H by the same means used in fixing 
 the point E. 
 
 1240. Horizontal Angles and Their Measure- 
 ment. — A horizontal angle is one the boundary lines of 
 which lie in the same horizontal plane. Let A, B, and C, 
 in Fig. 267, be three 
 
 points, and let it be re- .3,°30^- 
 
 quired to find the hori- A ^ 
 
 zontal angle formed by / 
 
 the lines A B and A C » i 
 
 joining these points. 
 
 Set up the instruments ^'^- ^'^• 
 
 precisely over the angular point A, and carefully level it. 
 Set the vernier at zero, and place the flag at B and at C 
 Sight the flag at B and set the lower clamp. Then, by 
 means of the lower tangent screw cause the vertical cross- 
 hair to exactly bisect the flag at B. Loosen the upper 
 clamp. With a hand on either standard, turn the telescope 
 in the same direction as that of the hands of a watch until 
 the flag at C is covered or nearly covered by the vertical 
 cross-hair. Clamp the upper plate and with the upper tan- 
 gent screw bring the line of sight exactly on the flag at C. 
 The arc of the graduated circle traversed by the zero point 
 of the vernier will be the measure of the angle B A C, equal 
 to 143° 30'. The points A, B, and C are not necessarily in 
 the same horizontal plane, but the level plate of the instru- 
 ment projects them into the horizontal plane in which it 
 revolves. 
 
 1 24 1 . A Deflected Line. — A deflected line, or " angle 
 line," is a consecutive series of lines and angles. The direc- 
 tion of each line is referred to the line immediately pre- 
 ceding it, which preceding line is, in imagination, produced, 
 and the angle measured between it and the next line actually 
 run. The angles are recorded R' or IJ, according as they 
 are turned to the right or left of the prolongation of the 
 immediately preceding line. An example of a deflected line 
 
632 
 
 SURVEYING. 
 
 «v 
 
 N 
 
 ^^^. 
 
 is shown in Fig. 2G8. Here the start- 
 ing point, A, of the line is a point in 
 the head-block of the switch at Benton 
 Station, O. & P. R. R. The point A 
 is, of course, in the center line of the 
 track. 
 
 Set up the transit at A with the 
 vernier at zero. Sight to a flag held 
 at F on the center line of the track, 
 O. & P. R. R. Loosen the vernier 
 clamp, and turn the telescope sight 
 to a flag held at B, the next point on 
 the angle line ; clamp the vernier, and, 
 by means of the tangent screw, ac- 
 curately sight to the flag held at B; 
 the angle reads 32° 30', and is record- 
 ed R^ 32° 30', with a sketch showing 
 the connection in which the term 
 head-block is designated by the abbre- 
 viation //^. ^. The bearing of the line 
 A B can not be taken at A on account 
 of the attraction of the rails. The 
 instrument is now moved to B, the 
 vernier set at zero and backsighted 
 to A ; the bearing oi A B,^ 75° 00' 
 E, is taken, and the number of sta- 
 tion -5, 2 + 90, together with the bear- 
 ing of A B, recorded. The telescope 
 is then reversed, pointing in the di- 
 rection B B'. The point C being de- 
 termined, the upper clamp is loosened 
 and the telescope turned to the right 
 and sighted to C. The reading of the 
 angle is found to be 14° 30', and re- 
 corded R* 14° 30'. It measures the 
 angle B' B C. The bearing of the 
 line B C, N 89° 20' E, is then re- 
 corded. The instrument is next set 
 
SURVEYING. 
 
 633 
 
 up at C, the vernier set at zero, backsighted to B, and then 
 reversed ; the deflection to D, R' 10° 00', is then read and 
 recorded, together with the number of the station at C, 
 6 + 85. This deflection measures the angle C C D, and 
 
 Station. 
 
 Defleetio-i Mag. Bearing. 
 
 Ded. Bearing. 
 
 Remarks. 
 
 13+63 
 
 
 
 
 End of Line. 
 
 10+31 
 
 L'30°00' 
 
 y. 69°25'E. 
 
 y. 69°30'E. 
 
 :^^^ 
 
 
 6+85 
 
 B'10°00' 
 
 8. 80°30'E. 
 
 S.80°30'E. 
 
 ^^n. 
 
 
 2+90 
 
 R^14°30' 
 
 N. 89°20'E. 
 
 N.89°30'E. 
 
 
 H nnf Stuilr.K 
 
 
 
 
 N.75°00'E. 
 
 
 8taM\ 
 
 at Benton Sta. 
 
 gives the direction of the line C D. A good form of notes 
 for such a survey is that given above. 
 
 1 242. Checking Angles by the Needle. — In spite of 
 the greatest care, errors in the reading and recording of 
 angles will occur. The best check to such errors is the 
 magnetic needle. And though it is not an exact check, 
 owing to the lack of precision in reading the needle and to 
 local attraction, yet it is the only reliable one, and in 
 universal use. 
 
 In Fig. 269, we have an example of the use of the needle 
 
 Fig. 269. 
 
G34 
 
 SURVEYING. 
 
 in checking angles. The bearing of the line A B, which 
 corresponds to y^ i^ in Fig. 208, is N 75" 00' E, and is 
 assumed to be correct. The bearing of the line B C, as read 
 from the needle, is N. 80° 20' E. Its deduced or calcu- 
 lated bearing is obtained as follows: To the bearing of 
 the line A B, N 75° 00' E, we add the R' deflection 14° 30'; 
 the sum is 89° 30', which is recorded in the column headed 
 Ded. Bearing. (See Art. 1241.) The deduced bearing, 
 it will be seen, is ten minutes greater than the magnetic 
 bearing as read from the needle and recorded in the column 
 headed Mag. Bearing. Had the deflection angle been re- 
 corded L* instead of R', the deduced bearing would have 
 been the difference between 75° 00' and 14° 30', which is 
 60° 30', and would be recorded N 60° 30' E. The magnetic 
 bearing being N 89° 20' E would have at once revealed the 
 error. The confusion of the directions R' and L' is the com- 
 monest source of error in recording deflections, though 
 sometimes a mistake of ten degrees is made in reading the 
 vernier. It is a wise precaution to read both angle and 
 bearing after they are recorded and compare them with the 
 recorded readings. 
 
 81^18^7 
 B 
 
 TRIANGULATION. 
 1243. Simple Triangrulatlon. — Triangulation is 
 
 an application of the principles of trigonometry to the 
 
 measurement of in- 
 accessible lines and 
 angles. A common 
 — -^ occasion for the use 
 
 ' of trigonometry is 
 
 illustrated in Fig. 
 270, where the line 
 of survey crosses a 
 stream too wide and 
 deep for actual 
 measurement. Set 
 two points A and 
 B on line, one on 
 
 Fig. 270. 
 
SURVEYING. 635 
 
 each side of the stream. Estimate roughly the distance 
 A B. Suppose the estimate is 425 feet. Set another point 
 C, making the distance A C equal to the estimated dis- 
 tance A B = 425 feet. Set the transit at A and measure 
 the angle B A C = say 79° 00'. Next set up at the point 
 C and measure the angle A C B -= say 5G° 20'. The 
 angle A B C is then determined by subtracting the sum 
 of the angles A and C from 180° ; thus, 79° 00' + 50° 20' = 
 135° 20'. 180° 00'- 135° 20'= 44° 40'= the angle ABC. 
 We now have a side and three angles of a triangle given, 
 to find the other two sides A B and C B. These sides 
 may be easily found by the methods given for the solution 
 of triangles (see Arts. '759, etc.) by drawing a line from 
 the vertex of one of the angles A or C so as to divide 
 the triangle ABC into two right-angled triangles. A 
 simpler and easier method, however, is the following: In 
 higher works on trigonometry, it has been demonstrated 
 that, in any triangle, the sines of the angles are proportional to 
 the lengths of the sides opposite to them. In other words, 
 sin A : sin B :: B C : A C; or, sin A : sin C::B C : A B, and 
 sin B : sin C::A C : A B. 
 
 Hence, we have sin 44° 40' : sin 56° 20' :: 425 : side A B. 
 Sin 56° 20' = .83228; . 
 .83228 X 425 = 353.719; 
 sin 44° 40' = .70298; 
 353.719 -^. 70298 = 503.17 ft. = side A B. 
 
 Adding this distance to 76 + 15, the station of the point 
 A, we have 81 + 18.17, the station at B. 
 
 Another and frequent occasion for the use of trigonome- 
 try is the following: Two tangents, A B and C D, Fig. 271, 
 which are to be united by a curve, meet at some inaccessi- 
 ible point E. Tangents (which will be more fully described 
 later on) are the straight portions of a line of railroad. The 
 angle C E F, which the tangents make with each other, and 
 the distances B E and C E are required. Two points A and 
 B of the tangent A B, and two points C and D of the tan- 
 gent C D, being carefully located, set the transit at />', and. 
 
636 
 
 SURVEYING. 
 
 backsighting to A, measure the angle E B C = 21° A5' ; set 
 up at C, and backsighting to D, measure the angle 
 £ C B=21° 25'. Measure the side B C= 304.2 ft. 
 
 F 
 
 Angle C'^jp being exterior to the triangle E B C is equal 
 (see Art. 1 1 94) to the sum of E B C and E C B =21° 45'+ 
 21° 25' = 43° 10'. The angle B £ C= 180° -C E E = 
 136° 50'. 
 
 From the principle stated we have sin 136° 50' : sin 
 21° 45' :: 304.2 ft. : side C E. 
 
 Sin 21° 45' = .37056; 
 
 .37056 X 304.2 = 112.724352; 
 
 sin 136° 50' = .68412; 
 
 side CE=s, 112.724352 -r- .68412 = 164.77 ft. 
 
 4^ 
 
 /50' 
 
 ly 
 
 
 •60 
 
 ~^ 
 
 J 
 
 .1^^ 
 
 y 
 
 FlO. 272. 
 
 Again, we find B E by the following proportion: 
 
 Sin 136° 50' : sin 21° 25' :: 304.2 : side B E\ 
 
 sin 21° 25' = .36515; 
 
 .36515 X 304.2 = 111.07863; 
 
 sin 136° 50' = .68412; 
 
 side^-£'= 111.07863-^.6841^=162.36 ft. 
 
SURVEYING 
 
 637 
 
 A building //, Fig. 272, lies directly in the path of the 
 line A B which must be produced beyond H. Set a plug at 
 B and then turn an angle D B C = 00°. Set a plug at C in 
 the line B C, at a suitable distance from B, say 150 feet. 
 Set up at C, and turn an angle B C D = 60°, and set a plug 
 at D, 150 ft. from C. The point D will be in the prolong- 
 ation of A B. Then, set up at D and backsighting to C, 
 turn the angle C D D' = 120°. I) D' will be the line re- 
 quired, and the distance B D will be 150 feet, since BCD 
 is an equilateral triangle. 
 
 A B and C D, Fig. 273, are tangents intersecting at some 
 
 inaccessible point H. The line A B crosses a dock O P, too 
 
038 SURVEYING. 
 
 wide for direct measurement, and the wharf L M. /^ is a 
 point on the Hne A B at the wharf crossing. It is required 
 to find the distance B //and the angle F // G. At />, an 
 angle of 103° 30' is turned to the left and the point E set 
 217' from B = to the estimated distance B F. Setting up 
 at E, the angle B F F is found to be 39° 00'. Whence, we 
 find the angle B F F = 1S0° - (103° 30' + 39°) =37° 30'. 
 From the above principle we have sin 37° 30' : sin 39° 00' :: 
 217 ft. : side B F. 
 
 Sin 39° 00' = .02932; 
 
 .02932 X 217 = 130.50244; 
 
 sin 37° 30' = .00870; 
 
 side B F= 130.50244 ^ .00870 = 224.33 ft. 
 
 Whence, we find the station of Fto be 20 + 17 -f- 224.33 = 
 22 + 41.33. Setup at F and turn an angle /TT^ 6^ = 71° 00', 
 and set up at a point G where the line C D prolonged inter- 
 sects/^ G. Measure the angle F G H — 57° 50', and the side 
 F G = 180. 3'. The angle F H G =180° - (71° + 57° 50') = 
 51° 10'. From the same principle as before we have sin 
 51° 10' : sin 57° 50' :: 180.3' : side F H. 
 
 Sin 57° 50' = .84050; 
 
 . 84050 X 180. 3 = 152. 02395 ; 
 
 sin 51° 10' = .77897; 
 
 side FH= 152.02395 -^ .77897 = 195.93 ft. ; 
 
 whence, we find the station of H to be 24+ 37.20. 
 
 1244. Vertical Angles. — A vertical angle is an 
 
 ry p angle formed by two intersecting 
 
 lines lying in the same vertical 
 
 plane, one of which is horizontal. 
 
 If the lines A B and A C, Fig. 
 
 j M^ '-^L 274, lying in the vertical plane 
 
 FIG. 274. D FFG, meet at the point A, 
 
 and the line A B is horizontal, the angle C A B is a vertical 
 
 angh\ and is measured by the arc B C. 
 
 1245. Intersection of Tangents. — Let A B and 
 
 C D, Fig. 275, be tangents whose point of intersection is to 
 
SURVEYING. 639 
 
 be determined and the angle which they make with each other 
 to be measured. First set up a flag or stake at B and another 
 at ^, or some other point in the line A B. Set up the tran- 
 sit at C, backsighting to D. Reverse the instrument. 
 Have a flagman hold a rod in the line C D, at the same time 
 putting himself in range with the stakes at A and B. With 
 a little practice he can nearly determine the intersection / 
 of the two lines. Then drive two stakes K and L firmly 
 in the line C D, one on each side of the point /. Their dis- 
 tance from the point / to be determined by the obtuseness 
 
 '^y^C Angle of Intersection, 
 
 \. 
 
 -/ 
 
 C 
 
 Fig. 275. 
 
 of the angle AID. Carefully center these stakes, driving 
 a tack half its length in each center. Stretch a cord between 
 these tacks. Next set up the instrument at B^ backsighting 
 to A. Reversing the telescope, set a flag at /, which will 
 be the intersection of the line A B prolonged with L D. 
 Drive a stake flush with the ground at /and drive a tack in 
 this stake where the prolongation of A B crosses the cord 
 connecting the stakes at A' and L. The point /is the inter- 
 section of the tangents A B and C D. The external angle 
 C I M, formed by the intersecting tangents, is called the 
 angle of intersection. 
 
 CURVES. 
 1 246. A line of railroad consists of a series of straight 
 lines and curves. In general, the straight lines, or, more 
 properly, the tangents, are first located and then they are 
 united by curves best fitting the ground lying between the 
 tangents. There are certain limits of curvature prescribed 
 for all roads, which must not be exceeded. These limits 
 
640 
 
 SURVEYING. 
 
 will depend upon conditions to be explained later. Rail- 
 road curves are circular and are divided into simple, covi- 
 pojind, and reverse curves. 
 
 A simple curve has but one radius, as y^ ^5 in Fig. 276, 
 whose radius is A C. 
 
 A compound curve, shown in Fig. 277, is a continuous 
 
 H 
 
 Fig. 277. 
 
 curve of two or more arcs of different radii, as C D E F, 
 which is composed of the arcs C D, D E, and E F, whose 
 respective radii are G C, H D, and K E. 
 
 A reverse curve, Fig. 278, is a continuous curve com- 
 posed of two arcs L M and M N oi the same or of different 
 
 radii described in the opposite 
 directions, and having a com- 
 
 ^^ ~ / x mon point J/, called the point 
 
 of reversal. Reverse curves, 
 
 though common in the early 
 
 days of railroad building in the 
 
 United States, are now con- 
 
 P'^- *"*• demned for roads of standard 
 
 gauge, and only admitted for narrow-gauge roads, when 
 
 cheapness of construction is the first requirement. 
 
 1247. Geometry of the Circle. — Before attempting 
 to lay out curves, a knowledge of geometry relating to the 
 circle must be mastered. The following propositions are of 
 special importance: 
 
 1. A tangent to a circle is perpendicular to the radius 
 drawn through its tangent point. Thus, A E, Fig. 279, is 
 perpendicular to B O, and C E is perpendicular to C O. 
 
SURVEYING. 
 
 641 
 
 2. Two tangents drawn to a circle from any point are 
 equal, and if a chord be drawn joining these points, the 
 angles between the chord and the tangents are equal. Thus, 
 B E and C E are equal, and the angles E B C and E C B 
 are equal. 
 
 3. An acute angle between a tangent and a chord is 
 equal to half the central angle subtended by the same chord; 
 thus, the angle EBC=ECB = one-half B O C, 
 
 4. An acute angle subtended by a chord, and having its 
 vertex in the circumference of a circle, is equal to half the 
 central angle subtended by the same chord. Thus, the 
 angle E B 6", whose vertex B is in the circumference and 
 subtended by the chord B G, is equal to half the central 
 angle BOG, subtended by the same chord B G. 
 
 5. Equal chords subtend equal angles at the center of a 
 circle and also at the circumference, if the angles are 
 
642 SURVEYING. 
 
 inscribed in similar segments. Tlius, i( B,G, G H, H K, and 
 /: Care equal, B O G= GO iT'and G B H = H B K. 
 
 6. The angle of intersection of two tangents equals the 
 central angle subtended by the chord uniting the tangent 
 points. Thus, the angle C E F= B O C. 
 
 1 248. Deflection Angeles. — When two lines meet in 
 the same plane, they are said to form an angle, and the point 
 of meeting is called the angular point. The rate of diver- 
 gence or deflection of the two lines from their common or 
 angular point determines the size of the angle. The unit 
 of angular measurement is the degree, equal to g-^ part of a 
 circle. Two lines forming an angle of one degree with each 
 other will, at a distance of one hundred feet from the angular 
 point, deflect or diverge 1.745 feet. 
 
 In Fig. 280, the lines A B and A C, meeting at the point 
 A, are supposed to form an angle of 1°, and the angle BAG 
 is measured by the arc B C, described with the radius A B, 
 
 Fig. 280. 
 
 which is 100 feet in length. The arc B C and the straight 
 line joining the extremities of that arc, i. e., the chord B C, 
 are assumed to be of equal length. 
 
 1249. Degree of Curvature. — The curve from 
 which, as a unit or basis, all other railroad curves are 
 deduced, is called a one-degree curve. It is the circum- 
 ference of a circle whose radius is 5,730 feet, or, more exactly, 
 6,729.05 feet, in length. Two radii forming an angle of one 
 degree at the center of a one-degree curve will subtend a 
 chord of 100 feet at its circumference. The arc subtended 
 by this chord of 100 feet is assumed to be of the same length 
 as the chord. 
 
 In Fig. 281, let A B and A C he radii 5,729.05 feet in 
 length, forming an angle of 1° at the center A ; then the arc 
 B C subtended by these radii will be 100 feet in length. The 
 curve B Ci^ called a 1° curve. If, from the point (? as a 
 
SURVEYING. 
 
 643 
 
 center, with a radius O B equal to 2,864.93 feet, we describe 
 an arc B D 100 feet in length, the radii O B and O D will 
 
 Bz5729,^LSi 
 
 Fig. 281. 
 
 form an angle of 2° at the center O, and the curve B D is 
 called a 2° curve. A curve whose radius is nearly one-third 
 A B, or 1,910.08 feet, is a 3° curve, etc. 
 
 The deji^ree of a curve is determined by the central 
 angle, which is subtended by a chord of 100 feet. Thus, if 
 B O G {Fig. 282) is 10° and B G is 100 feet, B G H K C is 
 a 10° curve. 
 
 Fig. 288. 
 
 The deflection an^le of a curve is the angle formed at 
 any point of the curve between a tangent and a chord of 100 
 feet. The deflection angle is, therefore, balf the degree 
 
044 SURVEYING. 
 
 of the curve. Thus, if the chord B G is 100 feet, the angle 
 E B G is the deflection angle of the curve B G H K C, and is 
 half the angle B O G. 
 
 Example.— Given the deflection angle EB G = D (Fig. 283), to find 
 the radius ^ C> = /?. 
 
 Solution. — Draw O Z perpendicular to B G. In the right-angled 
 
 triangle B O L, we have sin BOL = ^^; hut BO L = E B G = D, 
 
 since OL being perpendicular to the chord B G it bisects the arc 
 
 BLG. But the angle Z> = ij5(?G; hence, angle i5C>Z= A BL=z 
 
 50 feet and the radius BO = R. Substituting these values in the 
 
 50 
 given equation, we have sin D — —\ whence, j^ sin /? = 50, and we 
 
 have the formula 
 
 ^ = 7iF3- (89-) 
 
 For curves of from 1° to 10°, the radius may be found by dividing 
 5,730 ft. (the radius of a 1° curve) by the degree of the curve. The re- 
 sults obtained are sufficiently accurate for all practical purposes. For 
 sharp curves, i.e., for those exceeding 10°, the above formula, viz., 
 
 50 
 R — —. — =; should be used, especially if the radii are to be used, as a 
 sm Z> 
 
 basis for further calculation. 
 
 For example, the radius of a 4° curve is found by both methods as 
 
 follows: By first method, /? = 5,730 ft. -5- 4 = 1,433.5 ft. By second 
 
 method, we find the deflection angle Z> of a 4° curve is 2°. Applying 
 
 the formula, R = -^~-^, we have R = -—rr = 1,432.67 ft. 
 sm Z> .0349 
 
 In this case the error is only .27 foot, and may be ignored in prac- 
 
 5 730 
 tical work. For a 30° curve we have by first method, R = ' . =191 
 
 50 50 
 
 ft. By second method, we have R = -: — r^^ = ^..^^^ = 193.18 ft. In 
 ■^ sm 15 .25882 
 
 this case the error is 2.18 ft., and the error increases as the degree of 
 
 curve increases. 
 
 The radii given in the table of Radii and Deflections are calculated 
 
 . r . „ 50 
 
 by the formula R = —. — j^. 
 ■' sm D 
 
 1250. Sub-Chords for Curves of Short Radii.— 
 
 On curves of short radii, i. e., curves of 20° and upwards, 
 center stakes are driven at intervals of 25 feet. In Art. 
 1248, we stated that the standard chord and arc are as- 
 sumed to be of the same length. This is practically true 
 
SURVEYING. G45 
 
 for curves of large radii, but for curves above 20° the excess 
 of length of arc over the chord constantly increases. If, 
 now, in Fig. 282, the chord B C is 100 feet in length, the arc 
 B G H K C must be greater than 100 feet; and if the arcs 
 B G, G H, H K, and K C are equal, i. e. , each equal to one- 
 quarter the arc B H C, then the equal chords B G, G H, 
 H K, and K C subtending these equal arcs must each be 
 greater than one-quarter of B C, which we assumed to be 
 100 feet. These greater chords must, therefore, be greater 
 than 25 feet. Suppose the curve B H C to be a 20° curve, 
 and the chord B C, 100 feet ; then the central angle B O C 
 is 20°. As the arc B G is one-quarter of the arc B H C, the 
 
 20° 
 central angle B O G \s ~ = 5°. The line O L, drawn to 
 
 the middle point of the chord B G, is perpendicular to B G 
 and bisects the angle BOG. The deflection angle E B G = 
 B O L ^ G O L. Let C designate the chord B (7, 7?, the 
 radius O B and D, the deflection angle, E B G = B O L. 
 In the right-angled triangle B O L, we have sin B O L = 
 
 L> T 
 
 -fTj)- Substituting the above given values, we have sin 
 
 1 (^ 
 D = ^^jT-, whence \ C ^^ R sin D, and we have 
 
 C=1 RsmD. (90.) 
 
 The central angle for the chord B G is 5°. The deflection 
 
 angle D is, therefore, |° = 2° 30'. Sin 2° 30' =■ .04362. 
 
 Since the deflection angle E B C = 10° for this case, R =■ 
 50 ^ sin 10° = 287.94 ft. Hence, chord 6" = 2 X 287.94 X 
 .04302 = 25.12 ft. 
 
 Accordingly, in measuring the short chords, 25.12 feet 
 should be used instead of 25 feet. 
 
 1251. Tangent Distances. — When an intersection 
 of tangents has been made and the intersection angle meas- 
 ured, the next question is the degree of curve which is to 
 unite them, which being decided, the next step in order is 
 the location of the points on the tangents where the curve 
 
640 SURVEYING. 
 
 * 
 
 begins and ends. These two points are equally distant from 
 
 the point of intersection of the tangents, which is called the 
 
 P. I. The point where the curve begins is called the point 
 
 of curve, or the P.C. ; the point where the curve terminates 
 
 is called the point of tangent, or the P. T. The distance 
 
 of the P. C. and P. T. from the P. I. is called the tangent 
 
 distance. 
 
 In Fig. 282, let A B and C Dht, tangents intersecting at 
 
 the point E and forming an angle C E F=^ 40° 00' with each 
 
 other. It is decided to unite these tangents by a 10° curve 
 
 whose radius is 573.7 feet. Call the angle of intersection /, . 
 
 the radius B O, R, and the tangent distance B E, T. From 
 
 Art. 1247, proposition 6, we have B O C= C £ F; hence, 
 
 the angle B O E = ^ C E F. From the right triangle E B O 
 
 BE 
 
 we have tan B O E = -75-7^. 
 
 x> U 
 
 T 
 
 Substituting the above equivalents we have tan ^ /= -p, 
 
 whence T = R tzn ^ F. (91.) 
 
 In our example R = 573. 7 f t. ; ^ / = 20° ; tan 20° = . 36397. 
 573.7 X .36397 = 208.81 ft. Measure back from the point E 
 on both tangents the distance 208.81 ft. to the points B and 
 C. Drive plugs flush with the ground at both points and 
 set accurate center points, marked by tacks, in both. Di- 
 rectly opposite each of these plugs drive a stake called a 
 guard stalce, because it guards or rather indicates where 
 the plug is. The stake at B, if the numbering of the stations 
 runs from B towards C, will be marked P, C, and the stake 
 at C marked P. T. 
 
 1252. To Lay Out a Curve With a Transit.— 
 
 Having set the tangent points B and C, Fig. 282, set up 
 the transit at />, the P. C. Set the vernier at zero and 
 sight to E, the intersection point. Suppose B to be an even 
 or "full station," "say 18, and that it has been decided to 
 set stakes at each hundred feet. Let the central angle 
 B O 6\ measured by the 100-feet chord B G, be 10°; then, 
 the deflection angle E B G, whose vertex B is in the circum- 
 
SURVEYING. 647 
 
 ference and subtended by the same chord B G, will be ^ 
 B O G ox 5°. Turn an angle of 5° from B, which in this 
 case will be to the right; measure a full chain, 100 feet, 
 from B and line in the flag at G ; drive a stake at 6", which 
 will be marked 19. Turn off an additional 5° making 10° 
 from zero, and at the end of another chain, at //, set a stake 
 marked 20. Continue turning deflections of 5° until 20° or 
 one-half of the intersection angle is reached. This last 
 deflection, if the work has been correctly done, will bring 
 the head chainman to the point of tangent C. It is but 
 rarely that the P. C. comes at a full station. When the 
 P. C. comes between full stations it is called a sub- 
 station, and the chord between it and the next full 
 station is called a sub-chord. Had the P. C. of the curve 
 come at the sub-station, say 17 + 32, the deflection for the 
 sub-chord of 100 — 32 or 68 feet, the distance to the next 
 station, is found as follows: The deflection for a full station, 
 i. e., 100 feet, is 5° = 300', and the deflection for 1 foot is 
 
 1^ = 3', and for 68 feet the deflection will be 68 X 3 = 204' = 
 
 3° 24', which is turned off from zero and a stake set on 
 line, 68 feet from the transit, at Station 18. The length of 
 a curve uniting two given tangents whose intersection angle 
 is determined, is found as follows: 
 
 Suppose / = 32° 40', and that the tangents are to be united 
 by a 6° curve ; 32° 40' reduced to the decimal form is 32.666° ; 
 as each central angle of 6° will subtend a 100-foot chord, or 
 one chain, there will be as many such chords or chains as 6 
 is contained times in 32.666, which is 5.444, that is, there 
 will be 5.444 chains in the curve, or 544.4 feet, which is the 
 required length of the curve. The P. C. and P. T. having 
 been set and the station of the P. C. determined by actual 
 measurement, say 58 + 71, the station of the P. T. is found 
 by adding to 58 + 71, the station of the P. C, the calculated 
 length of the curve, 544. 4 feet. 58 + 71 + 544. 4 = 64 + 15. 4, 
 the station of the P. T. 
 
 Another method of calculation is the following: The sum 
 of all the deflection angles is equal to one-half the intersection 
 
648 SURVEYING. 
 
 angle. The intersection angle being 32° 40', one-half 
 equals 10° 20', which, reduced to minutes, equals *.»8()'. The 
 
 deflection for 100 feet is -° = 3° = 180', and the deflection 
 
 Z 
 
 180 
 for 1 foot ^s—-' = 1.8'; then, 980', the total deflection, di- 
 vided by 1.8', gives 544.4 feet, the required length of the 
 curve. 
 
 EXAMPLES FOR PRACTICE. 
 
 In the following examples, let /= angle of intersection, 7" = tan- 
 gent, and L = length of curve. 
 
 1. /= 16° 13', degree of curve = 3°, required, 7" and L. 
 
 Ans.j ^=272.13 ft. 
 ( L = 540.55 ft. 
 3. /= 59° 20', degree of curve = 8° 30', required, T'and L. 
 
 Ans \ ^'=384.32 ft. 
 ^"'- \ L = 698.04 ft. 
 
 3. /= 21° 35', degree of curve = 4° 15', required, 7" and L. 
 
 Ans \ 7^=257.03 ft. 
 ^"'- I Z = 507.84 ft. 
 
 4. The degree of a curve is 5° 30' ; what is the deflection angle for 
 a chord of 16.2 feet ? Ans. 26.7'. 
 
 5. The degree of a curve is 7° 15' ; what is the deflection angle for a 
 chord of 38.4 feet ? Ans. 1° 23^'. 
 
 1253. Obstructions in tlie Line of Curve. — Fre- 
 quently it happens that the entire curve can not be run in 
 from the P. C. on account of obstructions. This is especi- 
 ally the case in either hilly or wooded country, and the 
 transit has to "move up" to an intermediate point. For 
 example, in Fig. 282, we will suppose that Station //, 200 
 feet from B, is the last point which can be set from the 
 P. C. at B. A plug is driven at // flush with the ground 
 and carefully centered, and a tack driven at the point. The 
 deflection angle E B H is 10° to the right. The transit is 
 set up at //, an angle of 10° to the left is laid off from zero, 
 and the vernier clamped. The instrument is then sighted 
 to a flag at />, the spindle clamped, and a close sight to the 
 flag taken, the lower tangent screw being used to adjust the 
 sight. The vernier clamp is then loosened and the vernier 
 
SURVEYING. 
 
 649 
 
 set at zero. The line of sight will then be on a tangent to 
 the curve at H^ and the deflection angles to K and C can be 
 laid off as before and the stations K and C located. 
 
 1 254. Tangent and Chord Deflections.— Let A B 
 
 in Fig. 283 be a tangent, and B C E H 2i curve commencing 
 at B. Produce the tangent A B to the point D. The line 
 C D vs, 2i tangent deflection, and is the perpendicular 
 distance from the tangent to the curve. If the chord B C 
 be produced to the point 6", making CG^=BC=^C E, the 
 distance G E is 2i chord deflection and is double the 
 tangent deflection D C. 
 
 1255. Given the radius B O = R, Fig. 283, to find the 
 chord deflection E G and the tangent deflection C D = E E. 
 
 ^ 
 
 Fig. 283. 
 
 The triangles O C E and C E G are similar, since both 
 are isosceles, and the angle G C E = angle C O E. Hence, 
 
050 
 
 SURVEYING. 
 
 we have O C '. C E::C E \ E G. Denoting the chord C E 
 by c and the chord deflection E G by d^ we have, from the 
 above proportion, R \ cv.c \ d. Therefore, 
 
 ri ^ 
 
 ^=-^. 
 
 (92.) 
 
 To find the tangent deflection, draw C E to the middle 
 point of E G. By Art. 1254, E E = D C = the tangent 
 deflection. Hence, tangent deflection = one-half the chord 
 deflection, from which 
 
 tangent deflection = --75. (93.) 
 
 1256. Practical Method of Determining Tan- 
 gent and Chord Deflections. — Let it be remembered for 
 a basis of calculation that the chord deflection for a one- 
 degree curve, the chord being 100 feet in length, is 1.745 
 feet; for a 2° curve, double the deflection for a 1° curve, or 
 3.49 feet, and so on. The tangent deflection being one-half 
 the chord deflection, for a 1° curve it will be .873 foot, for 
 a 2° curve it will be 1.745 feet, etc. 
 
 Distances measured either on chords or tangents are 
 expressed in decimal parts of a station, which is 100 feet, and 
 
 Pig. 284. 
 
 is assumed as 1. Thus, the tangent deflection for 75 feet 
 will be expressed as the tangent deflection for .75 of a 
 station. This expression is, however, confined entirely to 
 
SURVEYING. G51 
 
 the calculation, and is spoken of as the tangent deflection for 
 75 feet. Fig. 284 will be used to demonstrate the principle 
 upon which tangent deflections are based. 
 
 Let A B he a. tangent, and B the P. C. of a 2° curve to 
 the right. We determine the chord deflection for 100 feet 
 chord of a 2° curve to be 3.49 feet. The tangent deflection 
 is one-half the chord deflection, or 1.745 feet. 
 
 Let B C = 100 feet, a full station (which express as 1), 
 then CL, the tangent deflection at C, will = 1.745 feet, for, 
 since this is a 2° curve, the chord deflection = 1.745 X 2, and 
 
 the tangent deflection = — — = 1.745 ft. 
 
 To find the tangent deflection for any intermediate point 
 G, 75 ft. from B, express the distance as a decimal of the 
 full station, or, in this case, .75. Square the decimal thus 
 formed, and multiply by the tangent deflection, in this case, 
 1.745; the result Avill be the tangent deflection for the point 
 considered. Thus, the tangent deflection for the point is 
 the line G K, and the length of 6^ A^ = . 75" X 1.745 ==.562 X 
 1.745:= .981 ft. 
 
 For the point /?, 125 ft. from B, the tangent deflection is 
 D M, and the length of D M is found as above. Thus, to 
 express 125 as a decimal of a full station, divide 125 by 
 100, obtaining 1.25. Then 1.25" X 1.745 = 1.562 X 1.745 = 
 2.725 ft. 
 
 In the above, we have assumed that the chord and the 
 corresponding tangents were of equal length; i. e., that 
 B 1= B F, B K— B G, etc. This is not strictly true, but 
 is near enough for all practical purposes, particularly when 
 the degree of the curve is small. 
 
 1257. Laying Out Curves Without a Transit.— 
 
 During construction, the engineer is often called upon to 
 restore center stakes on a curve when the transit is not at 
 hand. With the aid of a tape and a few stakes for lining in, 
 a line can be run closely approximating the true one, by 
 applying the principle demonstrated in Art. 1256. 
 
 A practical application of this principle is shown in 
 
G52 
 
 SURVEYING. 
 
 Fig. 285, in which A B is a tangent, B the P. C. of a 4° 
 curve RK The chord deflection of a 4° curve for 100 feet 
 chord is G.98 ft. The tangent deflection = \ the chord 
 deflection, is 3.49 ft. Let B = Sta. 8 + 25, a stake at each 
 full station on the curve being required. Restore the 
 stakes at A and B, which will determine the P. C, and give 
 the direction of the tangent A B. The distance from the 
 P. C. to the next full station C is 75 feet or .75 of a full 
 station; .75* X 3.49 = .502 x 3.49 = 1.9G ft., the tangent 
 deflection at C. The engineer being without a transit, the 
 point C is found by measuring 75 feet from B and setting a 
 stake at C in line with a stake at B, the P. C, and a point 
 A B C 
 
 Pig. 285. 
 
 on the tangent ^ .5 as A. With a tape, measure the dis- 
 tance 1.9G ft. from C at right angles to B C, and drive a 
 stake at that point /% which will be Station 9. Measure 
 100 feet from F and set a point at D in the line B F. By 
 previous calculation, we know the chord deflection for 
 100 feet is G.98 ft. Measure the distance 6.98 ft. at right 
 angles to the line FD and drive a stake at G, which will 
 be Station 10. In like manner set the remaining Station 11, 
 which is previously known to be the P. T. Although the 
 chord deflection Z^ C is not theoretically at right angles to 
 F D, yet D G is so small compared with FD that for curves 
 of ordinary degree the offset is made at right angles. 
 
SURVEYING. 653 
 
 EXAMPLES FOR PRACTICE. 
 
 1. The degree of curve is 5", the chord 67 ft. ; what are the tangent 
 and chord deflections ? . . ^ Tan def. =1.959 ft. 
 
 "^' "I Chord def. = 3.918 ft. 
 
 2. The degree of curve is 7^ 30', the chord 23.5 ft. ; what are the 
 tangent and chord deflections ? . \ Tan def. = .359 ft. 
 
 "^' 1 Chord def. = .718 ft. 
 
 3. The degree of curve is 6" 15', the chord 117 ft. ; what are the 
 tangent and chord deflections ? . ( Tan def. = 7.465 ft. 
 
 "^' 1 Chord def. = 14.930 ft. 
 
 1258. To Determine Degree of Curve by Meas- 
 uring a Middle Ordinate. — In track work, it is often 
 necessary to know the degree of a curve when no transit is 
 available for measuring it. The degree can be found by 
 measuring the middle ordinate of any convenient chord, and 
 multiplying its length by 8, which will give the chord deflec- 
 tion for that curve. 
 
 Let A B, in Fig. 286, be a 50-foot chord, measured on the 
 track, and let the middle ordinate ^ <^ be .44 ft. .44 X 8 = 
 3.53 = chord deflection for 6.44' 
 
 50', which, expressed in ^. 
 decimal part of a full sta- 50' 
 
 tion, is.5; .5' = .25. The fig. 286. 
 
 chord deflection for 100 feet multiplied by .25 = the chord 
 deflection for 50 feet, which we know by calculation to be 
 3.52 feet. Hence, 3.52-^.25 = 14.08 ft., the chord deflec- 
 tion for 100 feet, which, divided by 1.745, the chord deflec- 
 tion for a 1° curve, gives a quotient of 8.07, nearly. The 
 inference is that the curve is 8°. 
 
 EXAMPLES FOR PRACTICE. 
 
 1. Length of chord is 50 ft., middle ordinate .35 ft. ; required, de- 
 gree of curve. Ans. 6° 25.08'. 
 
 (The original curve probably 6' 30.) 
 
 2. Length of chord 40 ft., middle ordinate .21 ft. ; required, degree 
 of curve. Ans. 6' 1.02'. 
 
 (The original curve probably 6°.) 
 
 3. Length of chord 25 ft., middle ordinate .22 ft. ; required, degree 
 of curve. Ans. 16° 8.28 . 
 
 (The original curve probably 16".) 
 
G54 
 
 SURVEYING. 
 
 1259. Field Books. — To facilitate the field work of 
 the engineer, field books have been published. They are 
 portable, being carried in the pocket, and contain, in con- 
 densed form, general directions for the conduct of field work, 
 together with all the necessary data in the form of tables, 
 for prosecuting such work with accuracy and dispatch. 
 
 One of the first published in America is the work of John 
 B. Henck, to whom most American engineers are under 
 obligation. 
 
 1 260. Note Books. — Various styles of note books are 
 published, the pages being ruled to suit the particular kind 
 of work being done. They are of three classes, viz., transit, 
 level, and topography books. The latter are ruled in squares, 
 which may be given any desired scale and greatly facilitate 
 the accurate platting of topography in the field. 
 
 1261. How to Keep Transit Notes. — 
 
 A good form for location notes is the following: 
 
 SutUm, 
 
 OifltclioH 
 
 IU.An9U 
 
 M»f. Bemrinf. 
 
 De4. Btmring. 
 
 Bern 
 
 June 90. 1994 
 trk*. 
 
 
 
 
 
 
 
 
 
 9 
 
 
 
 
 
 
 
 T 
 
 
 
 
 
 
 
 «i*S 
 
 4°54'e.T 
 
 tfiX/ 
 
 if.as'io'g. 
 
 tr. afia'g. 
 
 
 
 t-no 
 
 4''00' 
 
 
 
 
 
 ^ 
 
 * 
 
 9°00' 
 
 
 
 ■ 
 
 
 ""V ffi^^ 
 
 9-Hm 
 
 9'00' 
 
 
 
 
 4*80 
 
 ^^••' 
 
 « 
 
 t°OV 
 
 
 
 
 S*40 
 
 $«^»" 
 
 4*90 
 
 »•«»' 
 
 S°W 
 
 
 
 
 
 4 
 
 *■>»«' 
 
 
 
 
 I»t.AufU-iS°00' 
 
 4'Cun*V 
 
 *HU> 
 
 o-w 
 
 
 
 
 T.-19>i.9t ft. 
 
 Dtf. Amflt f*r aOfttfOO 
 
 9**0 
 
 f.C4°M* 
 
 
 
 
 r.Ci-3*90 
 
 D*f.AmfUf»r tft.-l.r 
 
 9 
 
 
 
 
 
 L»»0a •/ 0mrmt-9nft 
 
 
 9 
 
 
 
 
 
 r.l>4*05 
 
 
 1 
 
 
 
 
 
 
 
 O 
 
 -. 
 
 
 a.9ois'M. 
 
 11.90° tS"*. 
 
 
 
 In the first column the station numbers are recorded. 
 In the second column are recorded the deflections with the 
 abbreviations P. C. and P. T., together with the degree of 
 curve and the abbreviation R' or IJ, according as the line 
 curves to the right or left. At each transit point on the 
 
SURVEYING. 655 
 
 curve, the total or central angle from the P. C. to that 
 point is calculated and recorded in the third column. This 
 total angle is double the deflection angle between the P. C. 
 and the transit point. In the above notes, there is but one 
 intermediate transit point between the P. C. and the P. T. 
 The deflection from the P. C. at Sta. 3 + 20 to the inter- 
 mediate transit point at Sta. 4 + 50 is 2" 36'. The total 
 angle is double this deflection, or 5° 12', which is recorded 
 on the same line in the third column. The record of total 
 angles at once indicates the stations at which transit points 
 are placed. The total angle at the P. T. will be the same 
 as the angle of intersection, if the work is correct. When 
 the curve is finished, the transit is set up at the P. T., 
 and the bearing of the forward tangent taken, which affords 
 an additional check upon the previous calculations. The 
 magnetic bearing is recorded in the fourth column, and the 
 deduced or calculated bearing is recorded in the fifth 
 column. 
 
 1 262. Preservation of Notes and Records. — Notes 
 should never be erased. If, on account of error or change of 
 plan, they should cease to be of any value, they are crossed 
 out, i. e., two diagonals are drawn across the page. All 
 notes of permanent location should be copied each day into 
 a separate book for office reference, to prevent confusion, 
 and for record in case the original notes should be lost. 
 
 LEVELING. 
 
 1263. A Level Surface. — A level surface is one 
 parallel to the surface of standing water. A water surface, 
 though not theoretically level, owing to the curvature of 
 the earth's surface, is assumed to be level and perpendicular 
 to a vertical line, or the line of gravity. 
 
 The height of a point is its distance above a given level 
 surface, measured on a vertical line, and is called its 
 elevation. The process by which the elevation of a point 
 is determined is called leveling. 
 
65G SURVEYING. 
 
 1264. Tlie Three Processes of Determining: 
 Elevations. 
 
 They are : 1st. By direct leveling. 
 
 2d. By indirect leveling ; and 
 3d. By barometric leveling. 
 
 1265. Direct Leveling. — In the process of direct 
 leveling, a level line either actual or visual is prolonged so 
 as to pass directly over or under the given point whose eleva- 
 tion is required. The elevation of any other point being 
 determined in the same way, the difference in the elevations 
 of the two points is found by subtracting the elevation of 
 the lower from the elevation of the higher. 
 
 1266. Indirect Leveling. — In the process of indirect 
 leveling, elevations are determined by means of lines and 
 angles. 
 
 1267. Barometric Leveling. — In barometric level- 
 ing the elevation of a point is determined by the weight of 
 the atmosphere at that point as registered by a barometer. 
 The second and third processes will be explained later. 
 
 DIRECT LEVELING. 
 
 1268. General Principles. — Direct leveling depends 
 upon three principles, two of which have already been 
 stated, viz. : First, that the surface of a liquid in repose is 
 level; second, that a vertical line is perpendicular to that 
 surface, and, third, that a bubble of air confined in a vessel 
 otherwise filled with liquid will rise to the highest point of 
 that liquid. A common application of the third principle is 
 seen in the spirit level used by carpenters and the level 
 board used by masons. 
 
 1269. The " Y " Level. — There are a great variety of 
 instruments for determining elevations. The one in most 
 general use is the " Y " level, shown in Fig. 287. 
 
 This instrument consists of an erecting telescope A B, 
 i. e., one which shows the image of the object to which the 
 telescope is directed in its erect or natural position, resting in 
 Y-shaped supports C and D, from which it takes its name. 
 
SURVEYING. 
 
 657 
 
 The line of sight, or collimation, is identical to that in the 
 transit explained in Art. 1225, and is parallel to the level 
 E F. The tube containing the eyepiece G has an exterior 
 ring //, which is milled to assist the hand in turning the 
 tube. This movement adjusts the eyepiece to the cross- 
 hairs. The object glass at B is moved in or out by the 
 milled headed screw A'; L and J/are parallel plates; the bar 
 O P supports the Y's and revolves on a spindle which is 
 
 FIG. 287. 
 
 clamped by the screw N. By means of the tangent screw X, 
 the telescope can be slowly turned horizontally. The tele- 
 scope is leveled by means of the leveling screws F, Q^ R, and S. 
 The level is supported by the tripod T. The cross-hairs are 
 of either platinum wire or spider threads, and are fastened 
 to a ring which is held in place by capstan screws shown at 
 U, and their movements are regulated in the same way as 
 the movements of the cross-hairs of the transit explained in 
 Art. 1225. 
 
fi58 SURVEYING. 
 
 1270. The Bubble Tube. — The bubble tube is of 
 glass bent upwards and so nearly filled with alcohol that only 
 a bubble of air remains, which is always at the highest point 
 in the tube. This tube is protected by a brass case, which 
 is fastened to the underside of the telescope, and provided 
 with the means for adjustment. The one end may be raised 
 or lowered and the other end moved horizontally. Through 
 a slit in the upper side of the case, the bubble tube is seen. 
 Directly over it is a scale graduated in both directions from 
 zero, which is over the center of the tube. 
 
 The Y's C and D support the telescope, which is held in 
 place by hinged clasps, or clips, as they are called, fastened 
 by carefully turned pins, by means of which the tele- ' 
 scope can be firmly held in any desired position. The Y's 
 rest upon the bar O P, to which they are fastened by lock- 
 nuts, the one above, the other below, the bar, for raising or 
 lowering. The bar revolves upon a finely turned steel spindle, 
 resting in a socket of bell metal. The parallel plates L and J/ 
 are united by a ball-and-socket joint, and held in place by the 
 leveling screws V, Q, R, and S. 
 
 1271. Adjustments. — The first thing todo in prep- 
 aration for actual leveling is to make the adjustments of 
 the instrument. 
 
 There are three adjustments, as follows: 
 
 1. To make the line of collimation parallel to the bottoms 
 of the collars, or rings, on which the telescope rests. 
 
 2. To make the plane of the level parallel to the line. of 
 collimation, or to the bottom of the collars. 
 
 3. To cause the bubble to remain in the center of the tube 
 while the telescope is being revolved horizontally. 
 
 1 272. First Adjustment. — To make the line of colli- 
 mation parallel with the bottoms of the collars. 
 
 Plant the tripod firmly ; choose some distant and clearly 
 defined point, the more distant the better so long as the 
 sight is distinct. Remove the pins from the clips and clamp 
 the spindle, bringing the intersection of the cross-hairs to 
 
SURVEYING. 659 
 
 exactly bear on the ^point by means of the tangent screw. 
 Revolve or turn the telescope on its supports through one- 
 half a revolution, i. e., until it is bottom side up. If the 
 intersection of the cross-hairs is still on the point of sight, it 
 proves that the line of collimation is parallel to the bottoms 
 of the collars. If, however, the line of sight is no longer on 
 the point, move the cross-hairs by means of the capstan* 
 headed screws over one-half the space which measures the 
 apparent error, being careful to move them in the opposite 
 direction to that in which it would appear they should be 
 moved. The apparent error is double the real error, and is 
 explained in Fig. 288. 
 
 Let the instrument stand at A and sight to the point B^ 
 and suppose that when the telescope has been revolved half 
 way around, the point B appears to be at C, then will the 
 
 _4 n 
 
 ' I \ Fig. 288. 
 
 distance B C h(t double the real error, and the true line of 
 sight will be at D, half way between B and C. Sometimes 
 both cross-hairs are out of adjustment and they must be 
 moved alternately until the intersection of the cross-hairs, 
 i. e., the line of collimation, will pass through the same 
 point throughout a complete revolution of the telescope. 
 
 1273. Second Adjustment. — The second adjustment 
 is to make the plane of the level parallel to the line of colli- 
 mation, or to the bottoms of the collars, and is made as 
 follows: 
 
 Remove the pins and open the clips; place the telescope 
 over a pair of leveling screws and clamp the spindle. Bring 
 the bubble to the middle of the tube by means of the level- 
 ing screws, and revolve the telescope through an eighth of a 
 revolution. The bubble tube will stand out at an angle with 
 the Y's. If the bubble runs it shows that a vertical plane 
 passed through the longitudinal axis of the bubble tube is 
 not parallel to a vertical plane passed through the line of 
 
6G0 SURVEYING. 
 
 collimation. To correct the error, bring the bubble nearly 
 back by means of the check nuts which regulate the lat- 
 eral movement of the tube, and repeat the operation until 
 the bubble ceases to run while the partial revolution is made. 
 To complete the bubble adjustment, level the telescope and 
 take it out of the Y's and turn it "end for end." If the 
 bubble remains in the center of the tube, the second adjust- 
 ment is complete. If it runs to one end, bring it half way 
 back by means of the check nuts provided for raising or 
 lowering one end, and the rest of the way, i. e., to the 
 middle of the tvibe, by means of the leveling screws. Re- 
 peat the operation, as the adjustment can rarely be made 
 with one trial. 
 
 1274, Third Adjustment, sometimes called the 
 *' Bar Adjustment." — This is to cause the bubble to re- 
 main in the center of the tube while the telescope is being 
 revolved horizontally. 
 
 Level the instrument, using both sets of leveling screws. 
 Having centered the bubble carefully with one pair of level- 
 ing screws, turn the telescope until it stands directly over 
 the other pair of leveling screws. If the bubble runs, bring 
 it half way back by means of the locknuts at the end of the 
 level bar and complete the leveling with the leveling screws. 
 Repeat the operation, as two or three trials will probably be 
 necessary to complete the adjustment, so that the bubble 
 will remain in the center of the tube throughout an entire 
 horizontal revolution of the telescope. 
 
 The adjustments of the level should be tested every day 
 when in constant use, as any defect in them will detract 
 from the value of the work done, and a serious defect will 
 necessitate a repetition of the work. 
 
 The cross-hairs are placed at right angles to each other, 
 one of which should be vertical and indicate to the leveler 
 whether the leveling rod is being held plumb. If the verti- 
 cal cross-hair is "out of plumb," adjust it by loosening the 
 capstan screws which hold the ring, to which the cross-hairs 
 are fastened. Suspend a plumb-bob at a suitable distance 
 
SURVEYING. 
 
 661 
 
 from the level, and having sighted to it, tap the capstan 
 screws sufficiently hard to cause the cross-hairs to move. 
 In this way the vertical hair can be made to coincide with 
 the plumb line, which is a true vertical. 
 
 1275. Sensibility. — The sensibility of the level de- 
 pends directly upon the radius of the curve of the bubble 
 tube. 
 
 The graduated scale placed directly over the bubble tube 
 measures the movement of the bubble. The sensibility of 
 the level may be determined as follows: Having leveled 
 the instrument, take a reading on the rod held say 200 feet 
 from the instrument. Suppose this reading to be 5.61 feet; 
 with the leveling screws cause the bubble to move over one 
 division of the scale. Suppose the rod then reads 5. 03 feet. 
 Denote the radius of the bubble by x. Fig. 289, the distance 
 
 5.61' 
 
 Fig. 289. 
 
 of the rod from the instrument by d, the difference of rod 
 readings by /i, and the movement of the bubble by 5. From 
 the approximately similar triangles we have h : S :: d : x. 
 
 or .03 : .01 :: 200 : x, whence x = 
 of the bubble tube. 
 
 2.00 
 .02 
 
 = 100 feet, the radius 
 
 1276. Use and Care of the Level. — The level 
 should not be used in rainy weather if it can be avoided. 
 Moisture obscures the lenses and is otherwise injurious to 
 the instrument. When rain is unavoidable, wipe the lenses 
 frequently with a soft linen handkerchief, and when re- 
 turned to the office or camp, thoroughly wipe, finishing with 
 a piece of dry chamois skin and place in a warm, dry place 
 so that every particle of moisture may be removed. Never 
 
662 
 
 SURVEYING. 
 
 carry the level with the spindle clamped. This rule is 
 especially important when working in a wooded country 
 where underbrush is dense. When undamped, the level 
 turns freely upon the spindle and yields readily to any pres- 
 sure. A blow which would inflict no injury upon an uu- 
 clampcd instrument might seriously damage one while 
 clamped and rigid. 
 
 X'il'l. Poiiver and Definition. — The power of a tele- 
 scope is measured by the apparent nearness to which the 
 image of the object is brought to the eye of the observer. 
 
 The definition of a telescope is measured by the degree of 
 clearness of the outline of the image. 
 
 1278. Target Rods. — Target rods are divided into 
 two classes, viz., those which are self-reading, or speaking 
 rods, and those which are not self-reading. 
 Railroad work is done chiefly with a self -reading 
 rod. That in most general use is called the 
 Philadelphia rod, and is shown in Fig. 290. 
 It is in two sections held together with brass 
 clamps A and B, one section sliding over the 
 other. When closed, the rod measures 7 feet, 
 sliding to 12 feet. It is graduated to feet, 
 tenths, and hundredths. The feet are marked 
 in large red figures, half above and half below 
 the marks of division; tenths of feet are 
 marked in black figures from 1 to 9, the lines 
 of division reaching half way across the face 
 of the rod; hundredths are marked by lines 
 yijy of a foot in width, alternating white and 
 black, and extending about one-third the way 
 across the face of the rod. The target is either 
 circular or elliptical and divided into quarters, 
 alternating red and white. The division lines 
 are so arranged that when the rod is held in a 
 vertical position one of them will be horizontal 
 Fig. 290. and the other vertical. The target C is fast- 
 ened to a collar which slides up and down the rod, and is 
 
SURVEYING. 663 
 
 fitted with a screw Z>, which clamps it at any desired point. 
 An opening more than one-tenth of a foot in length is cut 
 in the face of the target. A vernier is fastened to the target 
 whose zero point exactly coincides with the line which 
 divides the target horizontally. It lies within the opening, 
 on the face of the rod, and reads to thousandths of a foot. 
 To prevent wear, the foot of the rod is shod with brass. Rod 
 readings under 7 feet are usually taken with the two sections 
 closed, and the target moved up or down until the horizontal 
 line on the target coincides with the horizontal cross-hair of 
 the telescope. When readings of more than 7 feet are taken, 
 the clamp at B is loosened and the sliding section moved 
 upwards until the horizontal line of the target and the hori- 
 zontal cross-hair of the telescope coincide. The rod is then 
 clamped, and is called a long or higli rod, and can be 
 read to thousandths with the vernier attached to the collar 
 at B. In setting the target, the leveler should read the rod 
 as closely as he can with the level, calling the reading to the 
 rodman, who sets the target at the given reading and holds 
 the rod up for a check reading. Four times out of five 
 the leveler's reading will be the correct one, even to thou- 
 sandths. More mistakes are made in reading the number of 
 feet than the number of tenths. The leveler by first calling 
 the reading to the rodman will be certain to prevent such an 
 error, as it would at once be detected in the check reading. 
 An experienced rodman can hold a rod practically plumb, 
 and for all ordinary work his care is considered sufficient. 
 For work requiring the greatest possible accuracy, such. as 
 bridge foundations, a hand level, which fits closely to the 
 angle of the rod and carries two small spirit levels, is used to 
 accurately plumb it. In using a rod which is not self reading, 
 all readings are taken with the target. 
 
 1279. Examples in Direct Leveling. — The princi- 
 ples of direct leveling are illustrated in Fig. 291. 
 
 Let A be the starting point, which has a known elevation 
 of 20 feet. The instrument is set at B^ leveled up, and 
 sighted to a rod held at A . The target being set, the reading, 
 
664 
 
 SURVEYING. 
 
 8.42 feet, called a backsight, 
 is the distance which the point 
 where the line of collimation cuts 
 the rod is above the point A, and 
 is to be added to the elevation of 
 the point A. 20.00 + 8.42 = 28.42 
 is called the height of instrument 
 and designated H. I. The instru- 
 ment being turned in the opposite 
 direction, a point C is chosen, 
 which must be below the line of 
 sight. This point is called a turn- 
 ing point, and is designated by the 
 abbreviation T. P. Drive a peg 
 at C or take for a turning point a 
 point of rock or some other perma- 
 nent object upon which the rod is 
 held. The reading at this point is 
 a foresight, and is to be sub- 
 tracted from the height of the 
 instrument at B to find the ele- 
 vation of the point at C. 
 
 Let the rod reading be 1.20 ft. 
 As this reading is a foresight, it 
 must be subtracted from 28.42, 
 the height of instrument at B; 
 28.42 - 1.20 = 27.22', the ele- 
 vation of the point C. As 
 the ground rises abruptly, 
 the rodman should slide the 
 rod to its full length, being 
 careful to keep it 
 on the same point 
 C. The leveler car- 
 ries the instrument 
 to D, which should 
 o be of such a height 
 ■^-^ above C that when 
 
SURVEYING. 665 
 
 leveled up the line of sight will cut the rod near the top. 
 The backsight to fT gives a reading of 11. 5G ft., which, added 
 to 27.22 ft., the elevation of C, gives 38.78 ft., the height of 
 the instrument at D. The rodman then goes to E, a point 
 where a foresight reading is 1.35, which, subtracted from 
 38.78, the H. I. at D, gives 37.43 feet, the elevation of E. 
 The level is then set up at F, being careful that the line of 
 sight shall clear the hill at L. The backsight 6.15 ft. 
 added to 37.43 ft., the elevation of E, gives 43.58 ft., the 
 H. I. at F. The rod held at G gives a foresight of 10.90 ft., 
 which, subtracted from 43.58, the H. I. at F, gives 32.68, the 
 elevation at G. Again moving the level to H, the backsight 
 to G of 4.39 ft. added to 32.68, the elevation of G, gives 
 37.07 ft., the H. I. at H. Holding the rod at A' a foresight 
 of 5.94 subtracted from 37.07 gives 31.13, the elevation of 
 the point K. The elevation of the starting point A is 
 20.00 ft.; the elevation of the point K '\s found by direct 
 leveling to be 31.13 ft., and the difference in the elevations 
 of A and K is 31.13 — 20.00 = 11.13 ft. ; that is, the point 
 A' is 11.13 feet higher than the point A. 
 
 1280. A Datum Line. — A datum line is the base 
 line to which the elevation of every point of a series is re- 
 ferred. Thus, in Fig. 291, the datum line or plaice is 20 feet 
 lower than the point A, and the elevations of the points 
 A, B, C,D . . . .K are their elevations above this datum line. 
 Such a series of elevations is called a line of levels. 
 
 1281. Turning Points. — Turning points, men- 
 tioned in Art. 1279, are the points where backsights and 
 foresights are taken. The backsights are plus (-f-) readings, 
 and are to be added; the foresights are minus ( — ) readings, 
 and are to be subtracted. The rodman should make a peg 
 of well-seasoned oak, or other hard wood, about 9 inches in 
 length, 1 inch in diameter, sharpened at one end and 
 rounded at the other end, which is the turning point. For 
 driving the peg he should carry in a leather scabbard a 
 light hatchet. A point for a foresight having been deter- 
 mined, the rodman drives the peg firmly in the ground and 
 
666 
 
 SURVEYING. 
 
 holds the rod upon it. After the instrument is moved, set 
 up, and a backsight taken, the peg is pulled up and carried 
 in the pocket until another turning point is called for. 
 Turning points should be taken at about equal distances 
 from the instrument in order to equalize any small errors in 
 adjustment. In smooth country an ordinary level will per- 
 mit of sights of from 300 to 500 feet. A good rodman is as 
 necessary to accurate and rapid leveling as a good leveler. 
 A man who is inattentive to the work in hand, or averse to 
 rapid movement, is not fit for either place. In most locali- 
 ties, a line of levels of any considerable length will have 
 enough rough places in it, i. e., places where considerable 
 changes in elevation occur, to retard progress, however 
 diligent the level party may be. Laziness or carelessness 
 merit immediate discharge, and usually receive it. 
 
 1282. Bench Marks. — On railroad surveys, perma- 
 nent points called bench marks should be established at 
 intervals of from 1,000 to 2,000 feet, depending upon the 
 nature of the country. Any permanent object, such as a 
 
 stone door sill, a tree, or point 
 of large rock, will serve for 
 a bench mark. Where trees are 
 available, they are always used, 
 the point being cut on a pro- 
 jecting root. On preliminary 
 lines they should be as near to 
 the line as possible. A tree 
 with a large exposed root is 
 chosen, the bench mark is cut 
 into the root in the form of a 
 pyramid, a tack is driven into the apex and the rod held 
 upon it. The tree is blazed smooth and the letters B. M., 
 together with the elevation of the mark, written with red 
 chalk. A bench mark of this kind is shown in Fig. 202, the 
 point being at A and the elevation recorded at />. 
 
 1 283. Check Levels. — Check levels or test levels are 
 taken for the purpose of checking and proving the accuracy 
 
 v'W.^ 
 
 Fig. 292. 
 
SURVEYING. 6G7 
 
 of a line of levels before their adoption as a basis for con- 
 struction. Usually intermediate points or stations are not 
 taken, but only the turning points necessary to cover the 
 line. Readings are taken at all the bench marks, and the 
 correct elevations marked. The adjustments of the instru- 
 ment should be frequently tested, and the rodman should 
 carry a rod level to insure the plumbing of the rod. 
 
 1284. "Water Checks. — When the line of survey fol- 
 lows the shore of a body of water having no current, such 
 as a lake or pond, its surface can be used as a check, since 
 its level for any ordinary space of time will remain un 
 changed. The sea, whose level is constant, is the base 
 for all barometric leveling, and at all seaports for direct 
 leveling. 
 
 1285. Rapid Work. — The rate of progress is limited 
 by the transit party. If the country is open and rolling, 
 where long sights are frequent and chaining easy, the level 
 party will not keep up with the transit party. If the 
 country is smooth and open, both parties can make about 
 the same progress. If, however, the country is thickly cov- 
 ered with underbrush or heavy timber, the level party will 
 have much idle time. A good day's work will vary, accord- 
 ing to conditions, from three to eight miles. 
 
 The target should be set by signals given by the leveler. 
 An upward movement of the hand is the signal for raising 
 the target, and a downward movement the signal for lower- 
 ing it; a circle described by the hand is the signal for 
 clamping the target, and a wave with both hands indicates 
 that the target is properly set. 
 
 All intermediate readings are read by the leveler, whose 
 signal "All right" is a single outward wave of the hand, 
 the rodman being careful to keep the rod at full length. 
 
 The rodman should always call out the rod reading, giving 
 first the number of feet, or, if the reading is less than 1 foot, 
 call the figure " naught," never "ought," then pausing a 
 moment, call the decimal part of the reading. If the rod is 
 being read to hundredths only, the number, 8.40, is read: 
 
668 SURVEYING. 
 
 eight-four, naught; if 8.04, it is read: eight-naught, four. 
 If the rod is to be read to thousandths, the number, 8.401, 
 is read: eight-four, naught, one; if 8.410, it is read: eight- 
 four, one, naught. 
 
 The distinctness of a call is in no way proportional to the 
 amount of noise in it. A few days' practice will enable a 
 rodman with moderate effort to call a reading so as to be 
 distinctly heard at a distance of 500 feet. Should a high 
 wind be blowing, the sights will be shorter, owing to the 
 vibration of the instrument, and the rodman's work propor- 
 tionally lessened. The rod reading should always be re- 
 corded before moving the instrument. The leveler may 
 check the reading as he passes the rodman. In general, 
 however, the leveler relies entirely upon the accuracy of the 
 rodman's readings. If he can not be trusted, his place 
 should at once be supplied by one who can be trusted. 
 
 In taking levels on preliminary railroad surveys, frequently 
 the turning points, as well as intermediate stations, are 
 read by the leveler without being checked by the target. 
 The rodman has still plenty of occasion for the use of judg- 
 ment, as the rate of progress depends largely upon the care 
 shown in the selection of turning points. 
 
 1286. Sources of Error. — The principal sources of 
 error are defects in adjustment, which are the fault of the 
 leveler, and failure of the rodman to plumb the rod, and 
 wrong target readings, which are the fault of the latter. 
 Poor levelers and poor rodmen usually go in pairs. Haste 
 or hurry are poor helps to progress. One can do rapid and 
 accurate work without haste, but can not hurry and be 
 either rapid or accurate. 
 
 The sun shining directly upon the object glass confuses 
 the sight. To prevent this, most instruments are provided 
 with a sun shade, which fits the end of the telescope, 
 projecting over the object glass. 
 
 If the sun shade is lacking, the leveler can hold his hat so 
 as to shade the object glass. 
 
 Wind is also a source of error, as it causes the instrument 
 
SURVEYING. 669 
 
 to vibrate, thus preventing the accurate setting of the 
 target. The leveler should wait for a lull in the wind, dur- 
 ing which, if his rodman is alert, he can get a close shot. 
 At a second lull, he can check the target and feel safe in 
 moving ahead. 
 
 Individual errors, called "personal equation," are defects 
 in vision peculiar to the individual, so that two persons may- 
 set a target for the same rod, each giving a different read- 
 ing; but as this personal equation, or error, is constant for 
 the same person, it does not materially affect the accuracy 
 of work. 
 
 1287. Necessary Degree of Accuracy. — In prelim- 
 inary railroad work an error of .10 of a foot per mile is 
 allowable. Time spent in reducing such inaccuracies is 
 wasted. That painful degree of accuracy termed "hair- 
 splitting " is no recommendation, and the gain in accuracy 
 is more than balanced by increased cost and loss of time. 
 It is a well-known fact that small inaccuracies tend to bal- 
 ance each other, and that a line of levels covering 20 miles, 
 taken with a self -reading rod, will closely check a line taken 
 with target readings and rod level. 
 
 1 288. How to Keep Level Notes. — Forms for keep- 
 ing level notes are various. One of the best forms, rarely 
 or never seen in print, and yet one which is in general use 
 among engineers, is shown on the following page: 
 
 • The distinguishing feature of this form of level notes is a 
 single column for all rod readings. The backsights being 
 additive and the foresights subtractive readings, they are 
 distinguished from other rod readings by the characteristic 
 signs -\- and — . The turning points, whose foresight read- 
 ing is — , are further designated by the abbreviation T. P. 
 
 1289. How to Cbeck Level Notes. — There is one 
 method of checking level notes which is in universal use. It 
 provides for checking the elevations of turning points and 
 heights of instrument only, which is sufficient, as all other 
 elevations are deduced from them. The method is very 
 simple and depends upon the fact that all backsights 
 
670 
 
 SURVEYING. 
 
 
 o 
 
 d 
 
 •i 
 
 t— • 
 
 1— t 
 
 .£* 
 *-> 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 u - 
 
 a 
 B 
 
 4) 
 
 c 
 O 
 
 
 
 
 
 
 
 
 
 o 
 c 
 u 
 
 _c 
 'C 
 a. 
 
 
 
 
 
 
 
 E 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ♦J 
 
 3 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1) 
 
 o 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 c 
 _o 
 
 ♦J 
 
 > 
 
 o 
 o 
 
 d 
 o 
 I— 1 
 
 o 
 
 C5 
 
 o 
 
 CO 
 
 CO 
 
 C5 
 
 o 
 
 C5 
 
 C5 
 
 C5 
 CO 
 
 
 o 
 
 C5 
 
 o 
 o 
 
 o 
 
 CO 
 
 00 
 
 00 
 
 00 
 
 C5 
 
 
 o 
 
 CO 
 
 o 
 
 1— t 
 
 o 
 
 CO 
 
 1-5 
 
 o 
 
 l-H 
 
 o 
 
 05 
 
 CO 
 
 ■00 
 
 c 
 M 2 
 
 en 
 
 o 
 
 
 
 
 
 
 00 
 
 i 
 
 1—1 
 
 
 
 
 
 00 
 
 ci 
 o 
 
 l-H 
 
 
 
 
 i 
 
 3i 
 
 1—1 
 
 + 
 
 o 
 
 o 
 
 CO 
 
 o 
 
 00 
 
 o 
 
 1 
 
 5< 
 
 + 
 
 o 
 
 CO 
 
 o 
 
 o 
 
 1 
 
 »o 
 
 1— t 
 
 + 
 
 
 O 
 
 00 
 
 o 
 
 1— 1 
 
 CO 
 
 »o 
 I— 1 
 
 1 
 
 1. 
 
 Station. 
 
 
 o 
 
 T-H 
 
 »« 
 
 CO 
 
 a; 
 
 
 ■«*< 
 
 W3 
 
 5 
 + 
 
 
 
 » 
 
 i>. 
 
 00 
 
 
Thus, 100.00 
 
 10.22 
 
 5.61 
 
 2.52 
 
 5.41 
 
 11.53 
 
 11.57 
 
 24.27 
 
 122.59 
 
 
 24.27 
 
 
 SURVEYING. 071 
 
 are additive or + quantities, and all foresights are subtrac- 
 tive or — quantities. The level notes described in Art. 
 1288 are checked as follows: The elevation of the bench 
 mark at Station is 100.00 feet, to which all backsights or 
 -j- readings are to be added, and from this sum all foresights 
 or — readings are to be subtracted. The sum of the + 
 readings or backsights together with the elevation of the 
 bench mark at is 122.59. The sum 
 of the — readings or foresights is 
 24.27, and the difference 98.32 feet 
 is the elevation of the turning point 
 last taken. As soon as a page of 
 level notes is filled, the leveler should 
 check them, placing a check mark -^ 
 at the last height of instrument or 
 elevation checked. When the work 
 of staking out or cross-sectioning is being done, the levels 
 should be checked at each bench mark on the line. At the 
 close of each day's work, the leveler must check on the near- 
 est bench mark. 
 
 1290. Profiles. — A profile represents a vertical sec- 
 tion of the line of survey. In it all abrupt changes in 
 elevation are clearly outlined. Vertical and horizontal meas- 
 urements are usually represented by different scales. Irreg- 
 ularities of surface are thus rendered more distinct through 
 exaggeration. For railroad work profiles are commonly 
 made to the following scales, viz., horizontal, 400 feet = 
 1 inch ; vertical, 20 feet = 1 inch. 
 
 A section of profile paper is shown in Fig. 293. Every 
 fifth horizontal line and every tenth vertical line is heavy. 
 By the aid of these heavy lines, distances and elevations are 
 quickly and correctly estimated and the work of platting 
 greatly facilitated. The level notes described in Art. 1288 
 are platted in Fig. 293. The elevation of some horizontal 
 line is assumed. This elevation is, of course, referred to 
 the datum line, and is the base from which the other eleva- 
 tions are estimated. Every tenth station number is written 
 
672 
 
 SURVEYING. 
 
 at the bottom of the sheet under the heavy vertical lines. 
 The profile is first platted in pencil and then inked in black. 
 
 Fig. 293. 
 
 1291. Grade Lines. — The principal use of a profile 
 is to enable the engineer to establish a grade line, i. e., 
 
 a line showing the relative proportion of excavation and 
 embankment in the proposed work. The rate of a grade 
 line is measured by the vertical rise or fall in each hundred 
 feet of its length, and is designated by the term per cent. 
 Thus, a grade line which rises or falls 1 foot in each hundred 
 feet of its length is called an ascending or descending 1 per 
 cent, grade, and written + 1.0 or — 1.0 per hundred. A rise 
 or fall of one-half foot in each hundred feet is called a five- 
 tenths per cent, grade, and written + -5 or — .5 per 
 hundred. The grade line having been decided upon, it is 
 drawn in red ink. 
 
 Example. — The elevation of Station 20 is 140.0 feet; between Sta- 
 tions 20 and 100 there is an ascending grade of .75 per cent. ; what is 
 the elevation of the grade at Station 71 ? 
 
 Solution. — To obtain the elevation of the grade at Station 71, we 
 add to the elevation of the grade at Station 20, 140 feet, the total rise 
 in grade between Stations 20 and 71. Accordingly, 71 —20= 51; .75 
 foot X 51 = 38.25 feet; 140 + 38.25 = 178.25 feet, the elevation of grade 
 at Station 71. 
 
SURVEYING. 
 
 673 
 
 TOPOGRAPHICAL SURVEYING. 
 1292. General Deflnition. — Topographical sur- 
 veying is the location and representation of the inequalities 
 of any portion of the earth's surface. The portion surveyed 
 is conceived to be projected upon a horizontal plane, called 
 a plane of reference, upon which all inequalities of sur- 
 face as well as all conspicuous objects are shown in their 
 true relative positions. The simplest and most generally 
 used method of representing the topography of a given 
 surface is by means of contour lines. A map containing 
 an outline of a given surface, together with the contour 
 lines representing its inequalities, is called a contour map 
 of that surface. 
 
 70^ 
 
 Fig. 294. 
 
 Let A B C, \n Fig. 294, represent the outline of a hill, and 
 suppose this hill to be gradually submerged in water, the 
 water rising in successive heights of 10 feet. The flow, or 
 shore line, at each successive rise is a contour line. The 
 horizontal lines correspond to the surfaces of the successive 
 elevations of the water. The points where these horizontal 
 lines cut the edge of the hill are projected on the horizontal 
 
074 SURVEYING. 
 
 line L M. The irregular lines connecting the corresponding 
 points of projection are contours. In Fig. 294 they are 
 assumed to be 10 feet apart in vertical measurement. 
 
 1293. Conduct of a Topograptilcal Survey. — 
 
 The manner of conducting a topographical survey will de- 
 pend upon the extent and outline of the surface and the de- 
 gree of accuracy required. If the area be of comparatively 
 regular dimensions, such as town or park sites, the usual 
 practice is to lay out the area in squares. The lines of di- 
 vision are the bases for the location of all points within the 
 area whose elevations are determined by direct leveling. 
 If the area is long and narrow, as in a railroad survey, the 
 line of survey is the base for the location of all points and 
 for determining their elevations. Cross-sections of the sur- 
 face are taken at suitable intervals, and changes in the slope 
 of the surface are measured either by direct leveling or with 
 a clinometer or slope board. 
 
 1 294. The Hand Level. — The usual form, called the 
 "Locke level," from the name of the inventor, is shown in 
 Fig. 295. It consists of a brass tube A B, on the top of 
 which is a spirit level C. In the lower part of the tube is a 
 
 mirror which reflects the point at which the bubble should 
 be when the instrument is level. A small hole D at one end 
 and a cross-hair at the other give the level line. The ob- 
 server holds the level to one eye, bringing it to a level line 
 while he observes the object to which the level is directed 
 with the other. In taking cross-sections with a Locke level, 
 the following rule is recommended: The topographer has 
 two or more assistants, three is the better number, a rod- 
 man and two tapemen. The rodman is provided with a rod 
 at least 12 feet in length, of light weight, and of sufficient 
 width to admit of large, distinct figures being painted upon 
 
SURVEYING. 
 
 675 
 
 it, and divided to tenths of feet. The rod is painted like the 
 Philadelphia rod; the face white, tenths of feet in black, and 
 feet in red. Tapemen should use a tape 100 feet in length, 
 of durable material. Chesterman with wire warp is best. 
 The topographer first measures the distance of his eye above 
 th'e ground, which is a constant quantity, to be subtracted from 
 all the rod readings. He then stands at a station and keeps 
 the rodman at right angles to the line of survey. The rod- 
 man, having reached the end of a slope, i. e. , a point, where 
 the rate of slope changes, he holds his rod at the point and 
 the topographer takes the reading with the hand level. 
 From this reading the topographer subtracts the constant, 
 i. e., the height of his eye above the ground. The remain- 
 der is the difference between the elevation of the surface 
 where the topographer stands and the surface where the rod- 
 man stands. The tapemen having measured the distance 
 between the two points, the rate of slope is determined by 
 dividing the distance measured by the difference in eleva- 
 tion. This method of taking slopes or cross-sections is 
 illustrated in Fig. 296. 
 
 Let A be Station 156 of a preliminary survey. The topog- 
 rapher stands at A. The rodman goes to the point B^ 
 
 Fig. 2%. 
 
 where the slope changes, holding his rod, which measures 
 16 feet in length, at that point. The topographer sights 
 with his hand level and reads 7.5 feet on the rod. From this 
 reading he mentally subtracts 5.3 ft., the height of his eye 
 
676 SURVEYING. 
 
 above the ground. The remainder, 2.2 ft. , is the difference in 
 elevation between the points A and B. Meanwhile, the tape- 
 men find that the horizontal distance from y^ to ^ is 31 feet. 
 The rate of the slope yi Z>'is the horizontal distance between 
 the points A and^, 31 ft., divided by 2.2, their difference in 
 elevation. The quotient is 14.1 and the slope is recorded 
 
 — -^. The topographer then moves to the point B, and the 
 
 Ox. 
 
 rodman goes to C, which is so much lower than B that 
 with the rod held on the ground the line of sight will pass 
 over the top of the rod. Here the rodman gives a "long " 
 or "high " rod. Planting himself firmly at C, he raises the 
 rod until the line of sight, from the topographer's eye, cuts 
 the top of the rod, when the topographer calls "all right." 
 He then notes where the bottom of the rod comes, and 
 allows it to slide to the ground. Then adding to the length 
 of the rod 16 ft., the distance from the ground to the point 
 where the bottom of the rod came when the reading was 
 taken, he calls out their sum to the topographer. In this 
 example the rod is 16 feet and the addition 7 feet, making a 
 high rod of 23 feet, which is common enough. The hori- 
 zontal distance 33 feet, as measured by the tapeman, is also 
 called out. The topographer makes the subtraction 5.3 
 from 23.0, and the difference 17.7 is written as the numer- 
 ator of a fraction whose denominator is the horizontal dis- 
 tance 33. The slope being a descending one, the fraction 
 
 17 7 
 will be — -, a slope of 1 to 1.9. In Fig. 290, the slopes 
 
 A B and B C are right slopes, i. e. , on the right side of 
 the line of survey. 
 
 In taking the left slopes, the rodman and topographer 
 change positions, the topographer going ahead and the rod- 
 man following. The topographer standing at D reads a rod 
 of IG feet held at A. Subtracting the constant 5.3, the 
 remainder 10.7 is the difference between the elevations of A 
 and D and is an ascending slope. The horizontal distance 
 
 10.7 
 
 from ^ to Z> is 30 feet and the slope is recorded -f- 
 
 30 
 
SURVEYING. 
 
 677 
 
 1295. Slope Angles. — Slopes are often measured 
 with an instrument called a clinometer, which measures 
 the angle which the line of slope makes with the horizontal, 
 and is shown in Fig. 297. Tables are compiled giving the 
 
 Fig. 297. 
 
 angle of slope and the horizontal distance for one foot of rise, 
 as follows: 
 
 1° is 57.3 feet horizontal per 1 foot rise. 
 
 2° is 28.6 feet horizontal per 1 foot rise. 
 
 3° is 19.1 feet horizontal per 1 foot rise, etc. 
 
 1296. Platting Topography in the Field.— While 
 
 some engineers favor the platting of contour maps in the 
 field, the majority do not. To plat the map in the field, the 
 topographer carries a case, the cover of which serves for a 
 drawing board. The line of survey is divided into sections 
 which are platted on different sheets, each sheet containing 
 some of the immediately preceding section, so that by over- 
 lapping and pinning them together, a complete map of the 
 line is obtained. The topographer carries in his case the 
 sections covering his day's work, with the numbers and 
 elevations of each station marked on the map. He pins a 
 section to the cover of the case with thumb-tacks; his 
 assistants measure the angle of the slope with a clinometer, 
 
678 
 
 SURVEYING. 
 
 together with the horizontal distance ; and from the table 
 of slopes which he carries, the topographer determines the 
 location of the contours and sketches them on the map. A 
 better practice is to measure and record the slopes, keeping 
 as close to the transit party as possible, and provide an 
 extra man to work up the notes in the office under the 
 direction of the topographer. • 
 
 1297. Eye Measurements. — Though practice will 
 greatly aid the eye in estimating distances, yet it is not 
 to be relied upon when anything like exactness is required. 
 In taking slopes, the length of the last one only may b'e esti- 
 mated by the eye. More distant objects which lie without 
 the possible range of location may be sketched in with the 
 aid of the eye alone. 
 
 1298. Form of Topographer's Notes. — A good 
 form for a topographer's notes is shown in the accompany- 
 ing diagram : 
 
 Station. 
 
 Lt. 
 
 Line. 
 
 
 Rt. 
 
 Line. 
 
 
 
 ^ 45 
 
 10.0 
 + 30 
 
 
 11.4 
 35 
 
 -1? for 100' 
 
 1 
 
 for 60' 
 
 11.5 
 ^ 40 
 
 
 11.0 
 53 
 
 7 
 
 2 
 
 for 60' 
 
 10.3 
 
 ■^ 40 
 
 — 6 
 
 B 
 
 u 
 
 a 
 
 c 
 
 — 4) 
 
 o 
 
 11.5 
 50 
 
 -II for 100' 
 
 3 
 
 Same as 2 
 
 Same as 2 
 
 4 
 
 for 50' 
 
 11.8 
 ^ 40 
 
 10.5 
 55 
 
 - ^' for 100' 
 
 5 
 
 for 50' 
 
 12.0 
 ■^ 35 
 
 
 11.3 
 54 
 
 - '£ for ICKV 
 
 G 
 
 for 60' 
 
 10.4 
 ^ 40 
 
 
 10.5 
 50 
 
 - y for 100' 
 4.1 
 
SURVEYING. 
 
 679 
 
 PIO. 296. 
 
680 SURVEYING. 
 
 They are a record of the cross-sections or slopes ot a pre- 
 liminary railroad survey, the line of which extends along 
 the side of a steep hill. The slopes are taken with a Locke 
 level and rod, giving the actual differences in elevation be- 
 tween the points of change of slope. The alignment of the 
 survey is shown in Fig. 298, and the contours are platted 
 from the foregoing notes. The contours are 5 feet apart, 
 i. e., the vertical rise between them is 5 feet. 
 
 The elevations of the stations the topographer has 
 obtained from the leveler. The stations are marked on 
 the plat, either by a dot, or, what is better, a dot enclosed 
 in a small circle. The number of the station is marked at 
 the right a little space ahead of the circle, the elevation on 
 the left of the line and opposite to the number of the station. 
 The cross-section lines are sometimes drawn on the map, 
 very fine and at right angles to the center line, but usually 
 the lines are omitted, the draftsman giving the true 
 direction with his offset scale when locating the contours. 
 In Fig. 298, the elevation of Station is 104.6 feet. To 
 reach the next contour above, viz., 105, a rise of .4 foot 
 must be made, and to reach the next lower contour a fall of 
 4.6 feet is necessary. From the notes, we find on the left 
 of the line a rise of 10 feet in a horizontal distance of 30 feet 
 or a rise of 1 foot in 3 feet, and. for a rise of .4 foot we must 
 go to the left of the line .4x3 = 1.2 feet to contour 105. 
 To reach contour 110, which is 5 feet higher, we must go 
 5x3 — 15 feet farther to the left. This distance added to 
 1.2, the distance to contour 105, gives 16.2 feet, the second 
 offset. We find by adding 10 feet (the rise in going 30 feet 
 to the left of the line) to 104.6 feet, the elevation of Station 
 0, we have 114.6 feet, which is the elevation of the end of 
 the first slope. An additional rise of .4 foot must be made 
 in order to reach contour 115. The second slope is a rise 
 of .8.4 feet in a distance of 45 feet, or a rate of 1 foot in 
 5.3 feet. Multiplying 5.3 feet by .4, we have 2.1 feet, which 
 is to be added to 30 feet, to reach contour 115, and^fives a 
 distance of 32.1 feet. Contour 120 will be 5.3 feet X 5 = 
 26.5 feet beyond contour 115, or 58.7 feet from the center line. 
 
SURVEYING. 681 
 
 In the same way the contours to the right of the line are 
 located. Tenths of feet are dropped in the computed dis- 
 tances, as they are too small for platting, and the nearest 
 foot is taken. 
 
 Having located the contours by offsets for several con- 
 secutive stations, points of equal elevation are joined free- 
 hand, forming the contour lines, care being taken that lines 
 of different elevation are kept distinct from each other and 
 conforming to the curves and undulations of the original 
 surface. 
 
 1 299. Working Up Notes. — A good rule is to work 
 up the notes for a considerable section before platting, thus 
 avoiding the delay from continual change of work. The 
 following form of working up notes is a good one, notes for 
 each station being separated from those for other stations 
 by a few. strokes of a pencil. The example given is for 
 Sta. 0, in Fig. 298. 
 
 Sta. 0. Elev. 104.6. 
 
 Rt. 14 feet to contour 100. Lt. 1 foot to contour 105. 
 
 Rt. 29 feet to contour 95. Lt. 16 feet to contour 110. 
 
 Rt. 53 feet to contour 90. Lt. 32 feet to contour 115. 
 
 Rt. 81 feet to contour 85. Lt. 59 feet to contour 120. 
 Rt. 110 feet to contour 80. 
 Rt. 137 feet to contour 75. 
 
 Contour lines are usually drawn first with pencil and 
 afterwards inked in black. Short gaps are left in the lines 
 at suitable intervals, in v/hich their elevations are written. 
 These should be of sufficient frequency to show at a glance 
 the elevation of any contour. 
 
 Situations are continually recurring where the side slopes 
 give but an inadequate idea of the topography. This is 
 particularly true when the line of survey follows a stream 
 with numerous tributaries and where highway crossings are 
 frequent. In such cases the topographer will supplement 
 the side slopes with free-hand sketches, which are invaluable 
 helps in making topographical maps. 
 

 682 SURVEYING. 
 
 INDIRECT LEVELING. 
 
 1300. Indirect leveling is the process of determining 
 elevations by either lines or angles or both. A common 
 example in indirect leveling is given in Fig. 299. 
 
 Let D B he a. flag-staff whose height is required. Set up 
 a transit at A. Level carefully both the vernier plate and 
 
 ff the telescope. The 
 
 vertical arc will, if in 
 adjustment, read at 
 zero. Sight to C\ the 
 point where the hori- 
 
 -A jw, (44 g^j.j^gg ^^^ flag-staff. 
 
 4.2' ^ Measure the distance 
 
 FIG. 299. yi C = 180 feet, CD = 
 
 4.2 feet, and the diameter of the staff at C= 1.5 feet. 
 
 Measure the vertical angle C A B = 26° 10'. From rule 5, 
 
 Art. 754, we have tan A = , ,, , . ,. z=. One-half 
 
 A C -\- -^ dia. staff 
 
 diameter staff at C= .75 foot. Substituting known values, 
 
 we have tan 26° 10' = 7-^77^^^, whence C B— 180.75 X tan 
 
 180. i 5 
 
 26° 10'= 180.75 X.49134= 88.809 feet; 88.809 4-4.2 = 93.009 
 
 feet = D /)', the height of the flag-staff. 
 
 1301. Stadia Measurements. — The theory of the 
 stadia is familiar to most engineers, yet comparatively few 
 of them make any practical application of it, even when it 
 would be greatly to their advantage. 
 
 In stadia work an ordinary leveling rod is generally used, 
 and answers every purpose. It should be made of hard 
 wood, such as mahogany, which is least affected by changes 
 of temperature, and should be from 10 to 12 feet long, 
 2 inches wide, and about 1^ inches thick. It is divided into 
 feet, and each foot subdivided into tenths. The spaces 
 corresponding to these latter divisions are painted alter- 
 nately red and white, the number of tenths each space 
 represents being painted in prominent black figures on the 
 
SURVEYING. 683 
 
 lines of division. The space directly below each footmark 
 should be inlaid with a mirror to reflect the light and enable 
 the surveyor to read the rod at long distances with greater 
 precision. The rod should also be provided with a sliding 
 target. The best instrument tX) employ in this class of 
 work is a transit reading to 30". Besides the horizontal and 
 vertical cross-wires which appear in the field of view of the 
 ordinary transit telescope, the stadia transit is provided 
 with two additional horizontal wires placed parallel with 
 the horizontal wire in the plain transit, and at 
 
 an equal distance above and below it, as shown 
 
 in Fig. 300. These two extra wires are so 
 
 placed that, if the stadia rod is held at a point 
 
 100 feet distant from the telescope, they will 
 enclose 1 foot of the length of the rod. For ^^°- ^^• 
 example, if the lower wire coincides with the 4-ft. division, 
 and the upper wire with the 5-ft. division of the rod, the 
 distance from the center of the instrument to the rod will 
 be 100 ft. + the constant for the particular transit used. 
 The starting point for stadia measurements is often indis- 
 criminately assumed to be either the center of the instru- 
 ment, the center of the cross-wires, or from a plumb line 
 dropped from the object glass; but, owing to the deflection 
 of the sight due to the action of the lenses, the precise 
 starting point for stadia measurements is a point as far in 
 front of the object glass as its focal length ; for example, if 
 the focal length of the object glass is inches, the starting 
 point is 6 inches in advance of a plumb line dropped from 
 the object glass. The distance from this point to the centei 
 of the instrument is " constant " for the sduie instrument, 
 and must be added to the recorded stadia distance at every 
 sight. In making a stadia survey, the transit should first 
 be tested. Having found as level a plane as possible, test 
 and adjust the. level so that the vertical arc will read zero 
 when the telescope is in a perfectly horizontal position; 
 measure off very carefully from the center of the instru- 
 ment, the short distance equal to the constant of the instru- 
 ment, say 1.25 feet; from this point accurately measure a 
 
684 
 
 SURVEYING. 
 
 distance of 400 feet, driving a stake at each 100 feet. It is 
 advisable to measure this test line with two or more st£el 
 tapes, and then take the average. As it will be necessary 
 to test the cross-wires every few days, it is important that 
 the test line should be conveniently located and very accu- 
 rately measured. The line now measures 401.25 feet, as 
 follows: First section, measuring from the center of the 
 instrument, 101.25 feet, then three sections of 100 feet each, 
 as shown in Fig. 301. 
 
 ^.25 
 
 400' 
 
 Direct the rodman to hold the rod on the point 201.25 feet 
 from the instrument, and adjust the stadia wires so that 
 they will include 2 feet on the rod. First adjust the upper 
 to the center wire so as to include 1 foot, then adjust the 
 lower to the center to include one foot. When this has 
 been done, let the rod be held at the point 301.25 feet distant. 
 The wires should now inclose 3 feet, 1.5 feet being included 
 between the upper and center wires and 1.5 feet between 
 the center and lower wires. Now test the point at the ex- 
 tremity of the line ; the wires should at this distance include 
 4 feet. Instruct the rodman to hold the rod o'n the first 
 point, 101.25 feet from the instrument, and if the stadia 
 wires now include one foot, the instrument is in adjust- 
 ment; if not, the operations must be repeated until the 
 instrument^ reads correctly at every point. The ratio of the 
 constant does not increase with the distance, but remains 
 the same whether the distance of the sight be 50 or 2,500 
 feet. 
 
 At the .beginning of a survey, the target on the rod is set 
 at a height equal to that of the instrument, i. e., the dis- 
 tance from the ground-line to the axis of the telescope. 
 This is done with the view of having the line of sight par- 
 allel with an imaginary line between the foot of the instru- 
 
SURVEYING. 
 
 685 
 
 ment and the foot of the rod, which gives the exact vertical 
 angle or degree of slope between the instrument and rod 
 and a perfectly level plane. The rod is now held on a point 
 where a sight is desired, and the transitman turns the tele- 
 scope until the center wire and the center line of the target 
 coincide; see Fig. 302. He then clamps the telescope, and 
 reads the angle of elevation or depression, as the case may 
 be, on the vertical arc^ which is say 10° 26' ; and, if the rod 
 is held on a point at a greater elevation than that of the 
 telescope, this angle will be one of elevation, and he will 
 record it thus, + 10° 26'; but if the rod is held on a point 
 lower than the instrument, the telescope will be correspond- 
 ingly depressed, and the angle is recorded thus, — 10° 26'. 
 The distance on the rod intercepted by the stadia wires is 
 
 Fig. 302. 
 
 read and recorded. Assuming that the lower wire coincides 
 with the 3.5 ft. division line, and the upper one cuts the rod 
 at 7.46 feet, the intercepted distance is 7.46 — 3.5 = 3.96 
 feet, and is thus recorded. The needle is next read, or, if it 
 be an angular survey, the direction is platted and recorded. 
 Having thus obtained the vertical angle, intercepted dis- 
 tance, and bearing, this sight is finished and the surveyor is 
 ready to move to the next station. 
 
 Before any platting can be done, the distances must be 
 calculated and reduced to the horizontal. This may be ac- 
 complished by means of the table of Horizontal Distances 
 and Differences of Elevation for Stadia Measurements. In 
 using the tables, proceed as follows: Look for the vertical 
 angle, in this instance 10° 26', and under the head Hor. Dist. 
 find the number 96.72. Then, this number multiplied by 
 
686 SURVEYING. 
 
 the distance intercepted by the stadia wires, viz., 3.96, 
 equals 96.72 X 3.96 = 383.01; now, at the foot of the page, 
 under 10° and opposite c = 1.25 (the constant of the instru- 
 rnent), find the corrected distance 1.23, which, added to 
 383.01, gives 384.24: feet, the corrected horizontal distance, 
 which is recorded in the column provided for that purpose 
 in the note book. 
 
 The difference of level is found thus : Under the head 
 Diff. Elev., find 17.81, the number corresponding to the 
 vertical angle 10° 26'. This number multiplied by the in- 
 tercepted distance equals 17.81 X 3.96 = 70.53; at the foot 
 of the column find .23, which, added to 70.53, gives 70.76 
 feet as the difference of elevation, and is recorded as such 
 in its proper place. Proceed in the same manner to find 
 the horizontal distances and differences of level of all the 
 other points observed. The relative elevations of the vari- 
 ous points observed, above or below any adopted datum line 
 or plane of reference, can be readily determined by means 
 of the signs + and — prefixed to each vertical angle recorded. 
 Thus, assuming the survey to start from a B. M. 497.32 feet 
 above the adopted plane of reference, and the first angle re- 
 corded to be, as before stated, + 10° 26', corresponding to a 
 difference of level of + 70.76 feet, the point observed will be 
 497. 32 + 70. 76 = 568. 08 feet above th3 datum plane. Where, 
 however, boundary lines only are being run, it is unneces- 
 sary to compute the levels, but the vertical angles must be 
 recorded in all cases, in order to correct the distances. 
 
 The calculations may be made, without the use of tables, 
 in the following manner: 
 
 To obtain the horizontal distance, the following formula 
 is employed : 
 
 D—c cos n -\-a k cos' «, (94.) 
 
 in which D = the corrected distance ; c = the constant ; a k = 
 the stadia distance, and ;/ = the vertical angle. 
 
 Assume, as before, a vertical angle of + 10° 26' and an 
 intercepted distance of 3.96 feet. As each foot of the rod 
 intercepted by the stadia wires corresponds to a distance of 
 
SURVEYING. 
 
 687 
 
 100 feet, an interception of 3.90 feet corresponds to a dis- 
 tance of 396 feet, called herein the stadia distance, i. e., the 
 distance from the rod to the point outside the telescope 
 where the stadia measurement begins. 
 Applying the formula, we have, 
 
 D = 1.25 cos 10° 20' + 396 cos' 10° 26' = 
 125 X . 98347 + 390 X . 98347' = 384. 24 ft. 
 
 To obtain the difference of level E, apply the following 
 formula: 
 
 . , sin 2 « /rk- \ 
 
 Applying this formula to the preceding example, we have 
 E - 1.25 X .18109 + 396 X .17810 = 70.75, since 2 « = 
 
 10° 26' X 2 = 20° 52' and 
 
 sin 20° 52' .35619 
 2 
 
 = .17810. 
 
 SURVEY OF BEAVER CREEK. 
 
 c 
 
 c" 
 _o 
 '■3 
 
 OJ 
 
 5 
 
 4-> 
 
 cn 
 
 5 
 
 O 
 
 o 
 
 Bearing. 
 
 Vert. 
 Angle. 
 
 S 1 
 
 t I 
 21 o 
 
 
 
 1 
 
 396 
 
 384 
 
 N 1° 15 W 
 
 + 10° 26' 
 
 + 70.71 
 
 1142.21 
 
 
 A 
 
 201 
 
 
 Due E 
 
 + 20° 11' 
 
 
 
 
 B 
 
 404 
 
 
 S 80° 10 W 
 
 - 11° 14' 
 
 
 
 
 C 
 
 187 
 
 
 S 76° 20 W 
 
 - 14° 22' 
 
 
 
 
 D 
 
 563 
 
 
 S 68° 32 W 
 
 + 3° 12' 
 
 
 
 
 2 
 
 384 
 
 
 N 20° 15 W 
 
 - 0° 16' 
 
 
 
 The tables of Horizontal Distances and Differences of 
 Elevation for Stadia Measurements are computed for 
 observations taken on a vertical rod held perfectly plumb. 
 
 Fig. 303 shows the method of keeping sketch and notes in 
 topographical work. 
 
688 
 
 SURVEYING. 
 
 1302. An efflcient topoy^raphical survey is one 
 
 which fully serves every purpose for which it is made. Its 
 value depends more upon the accuracy of that which is 
 represented rather than the minuteness or quantity of 
 detail. The topographer should be able to readily and m- 
 telligently decide between what is important and what is 
 not important, and invest his time and labor accord- 
 
 FlG. 303. 
 
 ingly, taking nothing for granted and never indulging in 
 guesswork. 
 
 1303. The Aneroid Barometer. — Fig. 304 shows 
 an aneroid barometer, a substitute for the mercurial barom- 
 eter, which latter is not readily portable. It consists of a 
 box of thin corrugated copper, exhausted of air. An in- 
 crease in the weight of the atmosphere compresses the box, 
 and a reduction in weight admits of the box being expanded 
 by a spring inside. This spring is connected, by a system of 
 levers, with a dial which indicates the pressure of the 
 atmosphere. The face is graduated to correspond with the 
 heights of the mercurial barometer. A thermometer is also 
 
SURVEYING. 
 
 689 
 
 attached to the face and shows the temperature when the 
 readings are taken. 
 
 Fio. :J04. 
 1304. How to Determine Difference in Eleva- 
 tions With tlie Aneroid Barometer. — The formula 
 given is that used by the Engineer Corps of the United 
 States Army. The aneroid barometers used are adjusted 
 to agree with the mercurial barometer at a temperature of 
 32° Fahrenheit at the sea level in latitude 45°. Observa- 
 tions at the two stations whose difference in elevation is 
 required should be made as nearly simultaneous as possible, 
 as temperature and atmospheric conditions are constantly 
 changing. 
 
 Let Z — difference of elevation of the two stations in 
 feet; 
 // = the reading in inches of the barometer at the 
 lower station; 
 
690 SURVEYING. 
 
 //"= the reading in inches of the barometer at the 
 higher station; 
 / and /' = temperature (Fahr.) of the air at the two sta- 
 tions. 
 Then, 
 
 Z= (log//- log /^) X G0,384.3 X (l +^^^^=^). (96.) 
 
 Example. — Reading at lower station, /; = 29.52 in., / = 70°; at 
 higher station, H = 27.15 in., /' = 62°. 
 
 Log of /4, 29.52=1.47012 
 Logoff/, 27.15 = 1.43377 
 
 Difference = .03635 
 / + /'-64 . ^ 70+62-64 , .„„ 
 ^+ 900 =^^ 900 = 10'55- 
 
 Hence, Z= .03635 x 60,384.3 x 1.0755 = 2.360.4 feet, the diflference 
 
 between the elevations of the two stations. 
 
 Tables are prepared giving values of (log // — log H) X 60,384.3 and 
 
 t ■\- 1' — 64' 
 of 1 4 jjjr-r , which greatly simplifies the work of determining 
 
 differences of elevations. 
 
 HYDROGRAPHIC SURVEYING. 
 
 1305. Hydrographic surveying is the process of 
 determining, by means of soundings, the location of the deep 
 and shallow places of harbors, sounds, rivers, etc., and 
 recording them in charts for the use of engineers and 
 navigators. 
 
 1306. Sounding. — Sounding is measuring the depth 
 of water. The surface of the water forms the datum line, 
 and the various depths measure the undulations or changes 
 of elevation of the bottom of the body of water being 
 sounded. The extent of knowledge of the bottom gained 
 will depend upon the number and accuracy of the soundings. 
 
 For depths to 18 feet, a sounding rod graduated to feet 
 and tenths is used ; for greater depths, a lead line, marked 
 to fathoms and half fathoms, is employed. It will be found 
 necessary to keep the lead line well stretched and its length 
 frequently tested. 
 
SURVEYING. 
 
 691 
 
 1307. Conduct of Survey. — The mode of conduct- 
 ing a hydrographic survey is as follows: Stations at con- 
 spicuous points on shore are first carefully located by 
 trigonometrical surveying. They form the base line by 
 which all irregularities of shore line and the location of all 
 soundings are determined. A good station mark is a post 
 set firmly in the ground with about one foot of its length 
 exposed. A hole is bored in the center of the top of the 
 post and a flagpole set in it. The pole can be pulled out 
 and a transit set directly "over the station. Each station 
 should be distinguished by the combination of colors on the 
 flag, and the number of the station should be distinctly 
 marked on the post. A permanent bench mark must be 
 established and the height of water at the time of the 
 soundings recorded. 
 
 Buoys are made of light wood, and painted in such colors 
 as will make them conspicuous. 
 
 Fig. 305. 
 
 The location of buoys and soundings is illustrated in Fig. 
 .'>05. The stations A and B are located and their distance 
 apart known. A transit is set up at each station and back- 
 sighted to a rod at the other; the vernier plate is then un- 
 damped and the leadsman in the boat is carefully followed 
 with the instrument. At a given signal, the leadsman takes 
 a sounding, and both instruments sight to him and read the 
 angles, which give a side and two adjacent angles of a 
 triangle from which to determine the location of the point D. 
 In the same manner C and any number of points can be 
 located. A man in the boat records the time and the sound- 
 ings as they are read by the leadsman. 
 
692 SURVEYING. 
 
 1308. Tide Gauges. — By means of a tide gauge the 
 height of water at any time may be known. The datum or 
 zero line is mean low spring tide. A simple form of tide 
 gauge is a board nailed to the upright front of a dock. The 
 face should be painted white and graduated to half-feet or to 
 feet and tenths, and the zero line set at mean low spring tide. 
 The feet marks should be in heavy black figures, so that 
 they may be easily read. 
 
 The tide gauges used by the government are automatic, 
 and are provided with an indicator which registers on paper 
 the fluctuations of the tide. 
 
LAND SURVEYING. 
 
 1 309. The United States System of Surveying 
 Public Lands. — The public lands of the United States are 
 divided and laid out into approximately equal squares, the 
 sides of which are true north and south or east and west 
 lines. This is effected by means of meridian lines and 
 parallels of latitude established six miles apart. The squares 
 thus formed are called to^wnships, and contain 36 square 
 miles or sections. Each section contains, as nearly as may 
 be, 640 acres, giving an approximate area of 23,040 acres for 
 each township. 
 
 1310. Principal Meridians. — A principal merid- 
 ian running due north and south and a base line running 
 due east and west are established astronomically, and the 
 half-mile, mile, and six-mile corners are permanently marked 
 on them. These two lines form the basis of all subsequent 
 divisions into townships and sections. All other lines, with 
 the exception of these two and the standard parallels, are 
 run with the compass and chain. 
 
 Fig. 306 represents a section of country thus laid out. The 
 scale is 10 miles to 1 inch = 633600 : 1. The diagram shows 
 the principal meridian running truly north and south, and 
 a base line which is a parallel of latitude running truly 
 east and west. Parallel to these are other lines 6 miles apart, 
 forming townships. All the townships situated north or 
 south of each other form a range, the ranges being named 
 by their number east or west of the principal meridian. 
 The seven ranges east and seven west of the principal merid- 
 ian, shown in Fig. 306, are described as R. 1 E, R. 1 W, etc. 
 The townships in each range are designated by their num- 
 ber north or south of the base line. Thus, in the diagram. 
 
G94 
 
 LAND SURVEYING. 
 
 the township marked A is denoted by T. 3 N, R. 4 W; that 
 marked B, by T. 2 S, R. 3 E. These abbreviations should 
 
 l^Stknd^rd Parallel Noi^th. 
 
 Base 
 
 ,!S 
 
 Line. 
 
 It 
 
 1^^ Standard Parallel ^out h. 
 
 Fig. 306. 
 
 be read townsJiip 3 north, range J^ ivest, and toxvnship 2 
 south, range 3 east. 
 
 1311. To-v^'nslilp Divisions. — Each township is divi- 
 ded into 36 sections, each one mile square and containing 
 
 640 acres as nearly as 
 
 TV 
 
 ^ maybe. The sections in 
 
 each township are num 
 bered from 1 to 36, as 
 shown in Fig. 307. The 
 numbering of the sec- 
 tions begins at the north- 
 east corner of the town- 
 ship and goes west from 
 1 to 6, then east from 7 
 to 12, and so on alter- 
 nately until section 30 in 
 the southeast angle of 
 the township is reached. 
 The sections are sub- 
 divided into quarter-sections, each half a mile square and 
 
 W 
 
 6 
 
 5 
 
 4 
 
 3 
 
 2 
 
 1 
 
 7 
 
 8 
 
 9 
 
 10 
 
 11 
 
 12 
 
 18 
 
 n 
 
 16 
 
 15 
 
 14 
 
 13 
 
 19 
 
 20 
 
 21 
 
 22 
 
 23 
 
 24 
 
 30 
 
 29 
 
 28 
 
 27 
 
 26 
 
 25 
 
 31 
 
 32 
 
 33 
 
 34 
 
 35 
 
 3e 
 
 E 
 
 S 
 
 Fig. 307. 
 
LAND SURVEYING. 695 
 
 containing IGO acres, and sometimes into half quarter-sections 
 of 80 acres and quarter quarter-sections of 40 acres. By this 
 system the smallest subdivision of land can be accurately 
 located ; as, for example, the southeast quarter of section 36 
 in township one south in range two west of Willamette 
 meridian. 
 
 1312. Obstacles. — The law requires that the lines of 
 the public surveys shall be governed by the true meridian, 
 and that the townships shall be six miles square, two condi- 
 tions involving a mathematical impossibility, for strictly 
 conforming to the meridian would necessarily throw the 
 township out of square, for the reason that a degree of longi- 
 tude, which, at the equator, is 69^ miles, constantly dimin- 
 ishes as one approaches the poles. As the meridian lines are 
 strictly adhered to, the requirements of the law respecting 
 areas are not fulfilled. The townships assume a trapezoidal 
 form which increases the higher the latitude of the surveys. 
 To meet these conditions the law provides that the sections 
 shall contain G40 acres, as nearly as may be, and further pro- 
 vides that " in all cases where the exterior lines of the town- 
 ship thus to be subdivided into sections and half-sections 
 shall exceed or shall not exceed six miles, the excess or 
 deficiency shall be specially noted and added or deducted 
 from the western or northern ranges of sections or half- 
 sections in such township, according as the error may be in 
 running the lines from east to west or from south to north." 
 In order to throw the excesses or deficiencies, as the case 
 may be, on the«^r///and tcr.?/ sides of a township, according 
 to law, it is necessary to survey the section lines from south 
 to north on a true meridian, leaving the result in the northern 
 line of the township to be governed by the convexity of the 
 earth and the convergency of meridians. 
 
 Thus, suppose the land to be surveyed lies between 
 46° and 47° of north latitude. The length of a degree of 
 longitude in latitude 46° north is taken as 48.0705 statute 
 miles, and in latitude 47° north as 47.1944 miles. The dif- 
 ference, or convergency per square degree, = .8761 mile = 
 
696 LAND SURVEYING. 
 
 70.08 chains. The convergency per range (8 per degree of 
 longitude) equals one-eighth of this distance or 8. 76 chains, 
 and per township (11^ per degree of latitude) will equal 
 8.76 chains divided by 11^=. 76 chain. Hence, we know 
 that the width of townships along their northern boundary is 
 76 links less than on their southern boundary. The town- 
 ships north of the base line, therefore, become narrower and, 
 narrower than the six-mile width with which they start by 
 that amount. 
 
 1313. Standard Parallels. — Standard parallels, 
 called correction lines, are established at intervals of 
 30 miles to provide for the correction of the error arising 
 from the convergency of the meridians. They also serve to 
 limit errors resulting from inacciiracies in measurement. 
 Such correction lines .when lying north of the principal base 
 line form new base lines for the surveys north of them. 
 The convergency or divergency is taken upon these correc- 
 tion lines, from which, as base lines, the townships start 
 again with their proper widths. On these correction lines, 
 therefore, double corners will be found, one set being the 
 closing corners of the surveys ending there, and the other set 
 the standard corners of the surveys starting there. 
 
 1314. Running Township Lines. — The principal 
 
 meridian, the base line, and the standard parallels having 
 been first astronomically run, measured, and marked accord- 
 ing to instructions on true meridians and true parallels of 
 latitude, the process of running, measuring, and marking 
 the exterior lines of townships is as follows: 
 
 For townships north of the base line and west of the 
 principal meridian, commence at Station No. / (Fig- 308), 
 the southwest corner of T. 1 N, R. I W, as established on 
 the base line, thence run north on a true meridian line 
 480 chains, establishing the half-mile and mile corners there- 
 upon, according to instructions, to No. 2, which is the north- 
 west corner of the same township. There establish the 
 corner of townships 1 and l N, ranges 1 and 2 W; thence 
 run east on a random or trial line, setting temporary stakes 
 
LAND SURVEYING. 
 
 697 
 
 at the half-mile and mile points and noting the distance 
 where the line intersects the eastern boundary north or 
 south of the true or established corner. Run and measure 
 westward on the true line, establishing permanent half-mile 
 and mile corners, noting all water crossings and the charac- 
 ter of the land, as per instructions, to No. If., which is iden- 
 tical with No. 2. The last half-mile will fall short of 
 
 
 Standard 
 
 Parallel. 
 
 
 
 
 28 
 
 14 
 
 
 
 14 
 
 
 28 
 
 
 27 
 
 13 
 
 
 
 13 
 
 
 27 
 
 
 25 26 
 
 11 
 
 12 
 
 12 
 
 11 
 
 26 
 
 25 
 
 
 24 
 
 10 
 
 
 
 10 
 
 
 24 
 
 , 
 
 22 23 
 
 8 
 
 9 
 
 9 
 
 8 
 
 23 
 
 22 
 
 
 21 
 
 7 
 
 
 
 7 
 
 
 21 
 
 
 19 20 
 
 5 
 
 6 
 
 6 
 
 5 
 
 20 
 
 19 
 
 
 18 
 
 4 
 
 
 
 4 
 
 
 18 
 
 
 16 17 
 
 2 
 
 3 
 
 3 
 
 2 
 
 17 
 
 16 
 
 29 
 
 15 
 
 1 
 
 
 
 1 
 
 
 15 
 
 
 Base 
 
 
 e 
 
 
 Li 
 
 ne 
 
 
 
 
 - . 
 
 
 
 
 
 Pig. 808. 
 
 40 chains by about the amount of the calculated conver- 
 gency per township, which, in the above supposed case, 
 equals 76 links. 
 
 The terms random and true lines are explained in Fig. 
 309. The boundary from Station 1 to Station ^ is a true 
 meridian and 480 chains in length, with permanent corners 
 set at each half-mile and mile. From A run and measure 
 
698 
 
 LAND SURVEYING. 
 
 towards ^ on a true east and west line, as shown by ide dot- 
 ted line A B, which is called a random line, setting tem- 
 porary half-mile and mile posts. This random or trial line 
 being run on a parallel of latitude, must intersect the prin- 
 cipal meridian near the true corner C, previously established. 
 The return or true line always connects this true corner 
 with the one from which the random starts. Random lines 
 
 Random Line 479JSS chains" 47925 links. 
 
 >*^ '>A,^19^^0^40 40 40 40 40 40 40 40 40 39.23 
 
 '^^^^^^^^^^^^"io-lo-io-Jo-io-jo^ 
 True Line. 
 
 
 Sta.l 
 
 40 
 
 T.l.N.Rl.W. 
 
 S 
 
 Base Line. 
 
 5\ 
 
 •it 
 
 Fig. 309. 
 
 are either true east and west or true north and south lines, 
 i. e., they are either parallels of latitude or true meridians. 
 Suppose the random line intersects the principal meridian 
 X Fat i?, 75 links to the north of the true or established 
 corner at C\ the length of A B is 479 chains and 25 links. 
 The triangle A B C is a right-angled triangle, right angled 
 at B', dividing B C=75 links by A ^=47925 links, we 
 have the tangent of the angle BA C= j^Wr = .00156 = 
 
LAND SURVEYING. 699 
 
 tan 0° 05'. The angle B C A is, therefore, 90° = 0° 05' = 
 89° 55', and the return course, or true line, C A is 
 N 89° 55' W. Setting the instrument over the true or estab- 
 lished corner C, the compass is set for the true course C A, 
 N 89° 55' W, and measuring 40 chains from C, a permanent 
 half-mile or quarter-section post is set, 40 chains further a 
 mile or section post is set, and so on, setting half-mile and 
 mile posts at regular intervals of 40 chains until the last 
 half-mile post is set; between it and the township corner A, 
 the distance is but 39 chains and 25 links, thus leaving 
 the deficiency in the western tier of sections as prescribed 
 by law. 
 
 In case the random line materially falls short, or overruns 
 in measurement, or intersects the eastern boundary at a con- 
 siderable distance from the established corner, it will be evi- 
 dent that there has been considerable error either in direction 
 or measurement of the lines, or both, and the lines must be 
 retraced even if it should be found necessary to rerun the 
 meridianal boundaries of the township (especially the west- 
 ern boundary) so as to discover and correct the error. The 
 true corners must be established, and the false ones destroyed 
 and obliterated, and all facts carefully set forth in the notes 
 so as to avoid future confusion. 
 
 Then proceed north from 4 to 5, establishing corners as 
 before; No. 5 is the N W corner of T. 2 N, R. 1 W; east 
 to No. 6 (the N E corner of the same township), west 
 to No. 7 (the same as No. 5), north to No. 8 (the N W cor- 
 ner of T. 3 N, R. 1 W), east to No. 9 (the N E corner of 
 the same township), west to No. 10 (same as No. 8), north 
 to No. 11 (the N W corner of T. 4 N, R. 1 W), east to 
 No. 12 (the N E corner of the same township), west to 
 No. IS (same as No. ll), and thence north on a true merid- 
 ian to the standard parallel or correction line (which is here 
 five townships, or 30 miles, north of the base line), throwing 
 the difference over or under four hundred and eighty 
 chains on the last half mile, according to law. At the inter- 
 section with the standard parallel establish the closing corner, 
 the distance of which from the standard corner must be 
 
700 LAND SURVEYING. 
 
 measured and noted as required by the instructions. In 
 case any obstruction should have prevented the extension of 
 the standard parallel along the field of the present survey, 
 the surveyor will establish a corner for the township, subject 
 to correction, should the parallel be extended. The surveyor 
 then returns to the base line, and, from the southwest corner 
 of T. 1 N, R. 2 W, carries up another tier of townships, 
 closing as before. 
 
 For townships north of the base line and east of the prin- 
 cipal meridian the order of survey is as follows: Beginning 
 at the southeast corner of T. 1 N, R. 1 E, proceed as with 
 townships north and ivest, except that the trial or random 
 line is run and measured west and the true line east, throw- 
 ing the difference over or under 480 chains on the west end 
 of the line. Accordingly, the surveyor, having measured his 
 trial line west, will first determine the length of the last half- 
 section line, and commence the measurement of the true line 
 with such excess or deficiency, and, consequently, the re- 
 maining measurements will all be exact half miles and 
 miles. 
 
 1315. Running Section Lines. — The interior or 
 sectional lines of all townships, however situated with refer- 
 ence to base and meridian lines, are laid off and surveyed, 
 as shown in Fig. 310. 
 
 In this figure the squares and large figures represent sec- 
 tions; the small figures are referred to in the following di- 
 rections. Commence at No. 1 (see small figure in the 
 diagram) which is a township boundary for sections 1, 2, SS, 
 and 36; thence run north on a true meridian; at 40 chains 
 establish a half-mile or quarter-section post, and at 80 chains 
 establish the corner of sections 25, 26, 35, and 36. Thence 
 east on a random line to No. S, setting a temporary quarter- 
 section post at 40 chains, noting the measurement to No. 3 
 and the distance of the random's intersection north or south 
 of the true or established corner of sections 25, S6^ 30, and 
 31. Thence correct west on a true line to No. 4, setting the 
 quarter-section post on this line equidistant from the two 
 
LAND SURVEYING. 
 
 701 
 
 corners whose distance apart is now known. In like manner 
 proceed from J(.to 5, 5 to 6, 6 to 7, and so on to No. 16, the 
 corner of sections i, 2, 11, and 12, thence north on a random 
 line to No. 17, setting a temporary quarter-section post at 
 40 chains and noting the length of the whole line and the 
 distance of the random's intersection east or west of the true 
 corner of sections 1, 2, 33, and 36 established on the town- 
 ship boundary, then southwardly from the latter on a true 
 
 
 31 
 
 32 
 
 33 
 
 34 
 
 35 
 
 36 
 
 
 
 97 
 
 71 
 
 53 
 
 35 
 
 17 
 
 1 
 
 
 
 5 
 
 4 
 
 3 
 
 2 
 
 1 
 
 
 99 98 
 
 96 72 
 
 70 54 
 
 52 36 
 
 34 18 
 
 16 
 
 
 
 94 95 
 
 68 69 
 
 50 51 
 
 32 33 
 
 14 15 
 
 12 
 
 7 
 
 8 
 
 9 
 
 10 
 
 11 
 
 12 
 
 
 92 
 
 91 
 
 67 
 
 49 
 
 31 
 
 13 
 
 
 93 
 
 89 90 
 
 65 66 
 
 47 48 
 
 29 30 
 
 11 12 
 
 13 
 
 18 
 
 17 
 
 16 
 
 15 
 
 14 
 
 13 
 
 
 87 
 
 86 
 
 64 
 
 46 
 
 28 
 
 10 
 
 
 88 
 
 84 85 
 
 62 63 
 
 44 45 
 
 26 27 
 
 8 9 
 
 24 
 
 19 
 
 20 
 
 21 
 
 22 
 
 23 
 
 24 
 
 
 82 
 
 81 
 
 61 
 
 43 
 
 25 
 
 7 
 
 
 83 
 
 79 80 
 
 59 60 
 
 41 42 
 
 23 24 
 
 5 6 
 
 25 
 
 30 
 
 29 
 
 28 
 
 27 
 
 26 
 
 25 
 
 
 7T 
 
 76 
 
 58 
 
 40 
 
 22 
 
 4 
 
 
 ' 78 
 
 74 75 
 
 56 57 
 
 38 39 
 
 20 21 
 
 2 3 
 
 36 
 
 31 
 
 32 
 
 33 
 
 34 
 
 35 
 
 36 
 
 
 
 73 
 
 55 
 
 37 
 
 19 
 
 1 
 
 6 
 
 18 
 
 19 
 
 30 
 
 31 
 
 6 
 
 4 3 
 
 Fig. 310. 
 
 line, noting the course and distance to No. 16, the established 
 corner to sections 1, 2, 11, and 12, care being taken to estab- 
 lish the quarter-section post at 40 chains from said section 
 corner, thus throwing the excess or deficiency on the north- 
 ern half mile, according to law. Proceed in like manner 
 through all the intervening tiers of sections to No. 13, the 
 corner of sections 31, 32, 5, and 6. Thence north on a true 
 meridian 80 chains to 7^ setting a quarter-section post at 
 
702 LAND SURVEYING. 
 
 40 chains, and at 80 chains setting corner of sections 29, 30, 
 31, and 32; then east on a random to 75, setting temporary 
 quarter-section post at 40 chains, noting the entire measure- 
 ment to the eastern boundary and the distance of the ran- 
 dom's intersection north or south of the true corner of sec- 
 tions 28, 29, 32, and 33; thence west on a true line, setting 
 the quarter-section post on the true line and equidistant 
 from either end, to No. 76, which is identical with 74; thence 
 west on a random line to 77, setting temporary quarter-sec- 
 tion post at 40 chains, noting the full measurement of the 
 line and the distance of the random's intersection with the 
 township boundary nortJi or sontli of the established corner 
 of sections 30, 31, 25, and 3Q; thence eastwardly on the true 
 line, giving its course and setting the quarter-section post 
 40 chains from the corner of sections 29, 30, 31, and 32, thus 
 throwing the excess or deficiency of measurement on the 
 western half mile of the section according to law. Proceed 
 ftorth in like manner from No. 78 to 79, 79 to 80, 80 to 81, 
 and so on to No. 9J^, the southeast corner of section 6, where, 
 having established the corner of sections 5, 6, 7, and 8, run 
 thence successively the random line east to 95, nortli to 97, 
 and west to 99, and by reverse courses back on true lines to 
 the southeast corner of section 6, establishing the quarter- 
 section corners, and noting courses, measurements, and 
 distances as prescribed by law. 
 
 In townships contiguous to standard parallels the above 
 method is varied as follows: In every township sout]i of the 
 principal base line which closes on a standard parallel, the 
 surveyor will begin at the southeast corner of the township 
 and measure westward, establishing the half-mile and mile 
 corners and noting their distance from the preestablished 
 corners. He will then proceed to subdivide as directed 
 under the above head. 
 
 In townships north of the principal base line -which close 
 on the standard parallel, the section lines must be closed on 
 the standard parallel with true meridian lines instead of 
 course lines, as directed for townships otherwise situated ; 
 and the connections of the closing corners with the 
 
LAND SURVEYING. 703 
 
 preestablished standard corners are to be ascertained and 
 noted. 
 
 In case the surveyor is unable to close the lines on account 
 of the standard not having been run for some reason, as be- 
 fore mentioned, he will then plant a temporary post or con- 
 struct a mound at the end of the sixth mile, thus leaving 
 the lines and their connections to be finished when the 
 standard shall have been run. 
 
 1316. Water Frontage. — Departures from the gen- 
 eral system of dividing land have been authorized by law, 
 especially in the case of water frontage. 
 
 In surveying the public lands of Louisiana, which border 
 on rivers, streams, lakes, and bayous, surveyors were author- 
 ized to divide the land with water frontages of fifty-eight 
 poles and running back four hundred and sixty-five poles in 
 depth, "and of such shape and bounded by such lines as the 
 nature of the country will render practicable and most con- 
 venient. " Later, authority was given to survey lands with 
 two acres water frontage and running back a depth of forty 
 acres, tracts so surveyed to be offered for sale entire in- 
 stead of in half quarter-sections. In localities where it 
 would best subserve the interests of the people to have 
 fronts on the navigable streams and running back into the 
 uplands for timber, surveyors were authorized to increase 
 the quantity of land so as to give four acres frontage and 
 forty acres in depth, giving tracts of 160 acres, but in so 
 doing they were only to survey the lines between every four 
 lots (or 640 acres), establishing the boundary posts or mounds 
 in front and in rear, at the distances requisite to secure the 
 quantity of 160 acres to each lot, either rectangularly where 
 practicable or at oblique angles where otherwise. The angle 
 is not important so long as the principle is adhered to of 
 making, as far as possible, the rear lines square with the 
 regular sectioning. 
 
 1317. Meandering. — This name is applied to the 
 usual mode of traversing or surveying a navigable stream. 
 The instructions for this work are in part as follows: Both 
 
704 LAND SURVEYING. 
 
 banks of navigable rivers are to be meandered by taking the 
 courses and distances of their sinuosities and the same are 
 to be entered in the meander field book. At those points 
 where either the township or section lines intersect the 
 banks of a navigable stream, posts, or, where necessary, 
 mounds of earth or stone are to be established at the time of 
 running these lines. These are called " meander corners," 
 and, in meandering, the surveyor will commence at one of 
 these corners on the township line, coursing the banks and 
 measuring the distance of each course from the commencing 
 corner to the next "meander corner " upon the same or 
 another boundary of the same township, carefully noting 
 intersections with all the intermediate meander corners. 
 By the same method meander the opposite banks of the 
 river. 
 
 The crossing distance between the meander corners on the 
 same line is to be ascertained by triangulation, in order that 
 the river may be protracted with entire accuracy. The 
 particulars are to be given in the field notes. The courses 
 and distances on meandered navigable streams are the bases 
 for the calculation of the true areas of the tracts of land 
 (sections, quarter-sections, etc.), known to the law as 
 fractional and bounding on such streams. 
 
 The surveyor is also to meander, in manner aforesaid, all 
 lakes and deep ponds of the area of twenty-five acres and 
 upwards, also navigable bayous. 
 
 As traverse tables are generally calculated to 15' angles, 
 it is advisable to make meander courses read to quarter 
 degrees instead of intermediate minutes, except in closing or 
 where the extreme length of a side of a lake or stream falls 
 in one course. 
 
 The precise relative position of islands in a township made 
 fractional by the river in which they are situated is to be 
 determined trigonometrically. To meander islands crossed 
 by government lines, meander corners are previously estab- 
 lished at opposite points on the shore of the island, and the 
 meanders run from one to the other. Should the island not 
 be crossed by a line, measure a special base line from the 
 
LAND SURVEYING. 705 
 
 meander corner nearest to the island, triangulating to and 
 establishing at any convenient point on the island a special 
 meander corner from and to which the meanders of the island 
 start and close, 
 
 1318. Marking Lines. — All lines on which are to 
 be established the legal corner boundaries are to be marked 
 after this method, viz. : Those trees which may intercept 
 the line must have two chops or notches cut on each side of 
 them without any other marks whatever; these are called 
 sight trees or line trees. A sufficient number of other trees 
 standing nearest to the line on either side of it are to be 
 blazed on two sides diagonally or quartering towards the line, 
 in order to render the line conspicuous and readily traced, 
 the blazes to be opposite to each other, coinciding in direc- 
 tion with the line where the trees stand very near it, and 
 to approach nearer each other the further the line passes 
 from the blazed trees. Due care must ever be taken to have 
 the line so well marked as to be readily followed. 
 
 1319. Marking Corners. — After a true coursing 
 and most exact measurements, the corner boundary is the 
 consummation of the work for which all the previous pains 
 and expenditure have been incurred. A boundary corner in 
 a timbered country is to be a tree, if one be found at the 
 precise spot; and if not, di post is to be planted thereat, and 
 the position of the corner post is to be indicated by trees 
 adjacent (called bearing trees), the angular bearings and 
 distances of which from the corner are facts to be ascertained 
 and recorded by the surveyor. In a region where stones 
 abound, the corner boundary will be a small monument of 
 stones alongside of a single marked stone for a township 
 corner and a single stone for all other corners. 
 
 In a region where neither timber nor stone is available, 
 the corner will be a mound of earth of prescribed size 
 varying to suit the case. 
 
 When posts are used, their length and size must be pro- 
 portional to the importance of the corner, whether township, 
 section, or quarter-section post. 
 
706 
 
 LAND SURVEYING. 
 
 Township corner posts are three inches square and set at 
 least twenty-four inches above ground. 
 
 Where a township post is at a corner, common to four 
 townships, it is to be set in the ground diagonally, as shown 
 « in Fig. 311, and the cardinal points of the compass 
 indicated by lines cut or sawed out of its top at 
 p^-^ least one-eighth of an inch deep, as shown in the 
 figure. On each face of the post is to be marked 
 Fig. 311. the number and range of the particular township 
 which it faces. Thus, if the post be a common boundary 
 to four townships, viz., one and two south of the base line 
 and range two west, and also one and two south of the 
 base line and range three west, the face markings will be as 
 follows : 
 
 ( 
 
 R. 2 W 
 
 From N to E ^ 
 
 T. 1 S 
 
 ( 
 
 S31 
 
 / 
 
 3 W 
 
 From N to W - 
 
 1 S 
 
 1 
 
 36 
 
 1 
 
 2 W 
 
 From E to S - 
 
 2S 
 
 1 
 
 6 
 
 ( 
 
 3 W 
 
 From W to S - 
 
 2S 
 
 ( 
 
 1 
 
 R3W 
 TIS 
 
 R2W 
 TIS 
 
 R3W R2W 
 
 T2S T2S 
 
 Pig. 812. 
 
 The position of the post which is here taken as an 
 example is shown in Fig. 312. 
 
 These marks are neatly chiseled into the wood, and are 
 also marked with red chalk. The number of the sections 
 which they respectively face will also be marked on the 
 township post. • 
 
 Section or mile posts, being corners of sections, when 
 they are common to four sections, are to be set diagonally 
 in the earth (in the manner provided for township posts), 
 and with similar marks cut in the top to indicate the car- 
 dinal points of the compass, while on each side of the post is 
 
LAND SURVEYING. 707 
 
 cut the number of the particular section which the side 
 faces. Also, on one side is to be marked the number of its 
 township and range. To make such marks more conspicuous 
 and durable, red chalk is applied. A quarter-section or 
 half-mile post is to have no other mark than ^ S to indicate 
 what it stands for. 
 
 Township posts are to be notclicd with six notches on 
 each edge or angle corresponding to the cardinal points of 
 the compass. All mile posts on township lines must have 
 as many notches on opposite angles as they are miles dis- 
 tant from the corresponding township corners. Each of 
 the posts at the corners of sections in the interior of a town- 
 ship must have on their four angles, corresponding to the 
 cardinal points, as many notches as they are miles distant 
 from the corresponding township corners. The four sides 
 of the post will indicate the, numbers of the sections which 
 they respectively face. Should a tree be found at the place 
 of any corner it will be marked and notched in the manner 
 before described and will serve in place of a post; the kind 
 of tree and the diameter must be given in the field notes. 
 
 The position of all corner posts or corner trees of what- 
 ever description, which may be established, is to be perpet- 
 uated in the following manner, viz. : From such post or tree, 
 the courses shall be taken and the distances measured to two 
 or more adjacent trees in opposite directions as nearly as 
 may be, which are called bearing trees, and are to be blazed 
 near the ground with a large blaze facing the post and hav- 
 ing one notch in it, neatly and plainly made with an ax, 
 square across, and a little below the middle of the blaze. 
 The kind of tree and the diameter of each are facts to be 
 clearly set forth in the field book. 
 
 On each bearing tree the letters B. T. must be distinctly 
 cut into the wood in the blaze a little above the notch or 
 on the bark, with the number of the range, township, and 
 section. 
 
 At all township corners and at all section corners on 
 range or township lines y<7//r bearing trees are to be marked 
 in this manner, one in each of the adjoining sections. 
 
708 LAND SURVEYING. 
 
 At interior section corners four trees, one to stand 
 within each of the four sections to which such corner is com- 
 mon, are to be marked in the manner aforesaid if such be 
 found. 
 
 From quarter-section and meander corners, two bear- 
 ing trees are to be marked, one within each of the adjoining 
 sections. Stones at township corners (a small monument of 
 stones being alongside thereof) must have six notches cut 
 with a pick or chisel on each edge or side towards the car- 
 dinal points; and where used as corners in the interior of a 
 township, they will also be notched with a pick or chisel to 
 correspond with the directions given for notching posts 
 similarly situated. 
 
 Stones when used as quarter-section corners will have 
 \ cut on them, on the zvest side in nortJi and soutJi lines, and 
 on the nortJi side in east and zvcst lines. 
 
 Wherever bearing trees are not found, mounds of earth 
 or stone are to be raised around posts on which the corners 
 are to be marked in the manner aforesaid. Wherever a 
 mound of earth is adopted, the same will present a pyra- 
 midal shape. At its base on the earth's surface a quadran- 
 gular trench will be dug ; a spade deep of earth being thrown 
 up from the sides of the line outside the trench, so as to 
 form a continuous elevation along its outer edge. In mounds 
 of earth common to four townships or four sections, they 
 will present the angles of the quadrangular trench diagonally 
 to the cardinal points. In mounds common only to two 
 townships or two sections, the sides of the trench will face 
 the cardinal points. Prior to piling up the earth, in a 
 cavity, formed at the corner boundary point, is to be 
 deposited a stone, or a portion of charcoal; or a charred 
 stake is to be driven twelve* inches down into such center 
 point to be a witness for the future. The surveyor is 
 further specially enjoined to plant midway between each 
 pit and the trench seeds of some tree, those of fruit trees 
 adapted to the climate being always to be preferred. 
 
 Double corners are to be found nowhere except on the 
 standard parallels or correction lines whereon are to appear 
 
LAND SURVEYING. 709 
 
 both the corners which mark the intersection of the lines 
 which close thereon and those from which the surveys start 
 in the opposite direction. 
 
 The corners which are established on the standard 
 parallel at the time of running it are to be known as 
 ^'- standard corners,'" and in addition to all the ordinary- 
 marks (before described) they will be marked with the 
 letters S. C. The closing corners will be marked C. C. 
 
 1320. Field Books. — There are several field books, 
 viz. : 
 
 1. Field Books for the meridian and base lines, show- 
 ing the establishment of toiunship, section, or mile, and 
 quarter-section, or half-mile boundary corners thereon ; with 
 the crossings of streams, ravines, hills, and mountains; the 
 character of the soil, timber, minerals, etc. These notes 
 will be arranged in series by mile stations consecutively 
 from number one to number . 
 
 2. Field Books for the standard parallels or correction 
 lines, showing the establishment of the township, section, and 
 quarter-section corners, besides exhibiting the topography of 
 the country on line as required on the base and meridian 
 lines. 
 
 3. Field Books for exterior lines of townships, showing the 
 establishment of the corners on line, and the topography as 
 aforesaid. 
 
 4. Field Books for the subdivision of townships into 
 sections and quarter-sections; at the close whereof will 
 follow the notes of the meanders of navigable streams. 
 Those notes will also show by ocular observation the estima- 
 ted rise and fall on the line. A description of the timber, 
 undergrowth, surface soil, and minerals upon each section 
 line is to follow the notes thereof, and not be intermixed 
 with them. 
 
 5. The Geodetic Field Book, comprising all triangulations, 
 angles of elevation and depression, leveling, etc. 
 
 1321. Retracing Old Lines. — The original surveys 
 of lands in the older States of the American Union were 
 
710 
 
 LAND SURVEYING. 
 
 imperfectly made and full of errors. This was owing to two 
 principal causes; viz., the cheapness of the lands and the 
 lack of skill in the surveyors. Boundary lines described in 
 deeds and shown in maps as straight are found to be crooked 
 on the ground; tracts contain less or more land than 
 called for in descriptions. Records of adjoining tracts make 
 one to overlap another or leave an unclaimed gore between 
 them. These discrepancies and blunders often render the 
 work of the surveyor, when retracing old boundaries or 
 establishing corners, exceedingly difficult, and great tact and 
 judgment are often necessary in making amicable and satis- 
 
 FiG. 318. 
 
 factory adjustments of contending claims. In general, old 
 boundaries, such as line trees, stone monuments, and fences 
 are accepted as holding ; but, before retracing lines the 
 surveyor should, if possible, secure the consent of adjacent 
 owners to abide by such monuments and boundaries, irre- 
 spective of the lines or quantities called for in contracts or 
 deeds. It must be borne in mind that the bearings of lines 
 are each year undergoing a slight change which, in a long 
 period, amounts to several degrees, and if the lines were re- 
 run according to original bearings as given in descriptions, 
 they would enclose a tract differing widely from that in- 
 cluded in the original survey. The surveyor must accord- 
 
LAND SURVEYING. 
 
 711 
 
 ingly determine the amount of magnetic variation or change 
 which has taken place between the time of the original 
 survey and the date of the survey about to be made, and 
 having determined such change or variation, he must make 
 the original bearings conform to the calculated variation 
 before commencing the survey. 
 
 Fig. 313 illustrates the effect of magnetic variation in 
 altering the direction of lines. The figure A B C D Ogives 
 the outline of a tract according to the original survey, and 
 A B' C D' E' the relative directions of the boundaries when 
 resurveyed with the original bearings, there having been 
 during the intervening time a change in magnetic variation 
 of 3° west. 
 
 Let columns 1, 2, and 3 in the accompanying diagram 
 give the courses, original bearings, and distances, and col- 
 umn 4 the cor- 
 
 rected bearings 
 which the original 
 boundaries will 
 have, when allow- 
 ance has been 
 made for the mag- 
 netic variation. 
 When the north 
 end of the needle 
 has been moving westerly, i. e., when the variation or chatige 
 is west, the corrected or present bearings will be the sums of 
 the change and the old bearings which were northeasterly or 
 soiitJnvesterly and the differences of the change and the old 
 bearings which were northwesterly or southeasterly ; when 
 the variation or change is easterly^ the corrected or present 
 bearings will be the differences of the change and the old 
 bearings which were northeasterly or southwesterly and the 
 sujus of the change and the old bearings which were north- 
 westerly or southeasterly. 
 
 It will be seen, by reference to Arts. 1211 and 1212, 
 that declination is the reverse of i>ariation, i. e. , a west decli- 
 nation results when the variation or movement of the N end 
 
 1 
 
 2 
 
 3 
 
 4 
 
 Courses. 
 
 Bearings. 
 
 Distances. 
 
 Corrected 
 Bearings. 
 
 A B 
 
 N68°00' E 
 
 210 
 
 N7r00' E 
 
 B C 
 
 S 73° 00' E 
 
 200 
 
 S 70° 00' E 
 
 CD 
 
 S 8° 00' E 
 
 162 
 
 S 5° 00' E 
 
 D E 
 
 S 87° 00' W 
 
 326 
 
 S 90° 00' W 
 
 EA 
 
 N 28° 00' W 
 
 176 
 
 N 25° 00' W 
 
712 LAND SURVEYING. 
 
 of the needle is to the east, and <'rtj/ declination results when 
 the movement of the N end of the needle is to the west. 
 By this rule the bearings given in column 4 are obtained. 
 Before commencing the survey, the surveyor should cor- 
 rect all the bearings and write them out together with the 
 original bearings in their proper order. 
 
 1322. How to Determine Magnetic Variation. — 
 
 If the date of the original survey is known, the amount of 
 variation may be determined from published tables giving 
 the yearly variation for different sections of the country, but 
 the date of the survey is often omitted. The date of the 
 deed must not be taken as the date of the survey. 
 
 If one of the original boundaries remains unchanged, the 
 magnetic variation can be determined at once by taking the 
 present bearing of the line. The difference between the 
 present bearing and that of the original survey is the re- 
 quired correction. The corrections are then to be made in 
 the original bearings and the resulting courses run out. 
 Where the measurements fall short of or overrun the 
 original measurements, corrections must be made, locating 
 the original corners if they can be found or establishing new 
 ones, and, if possible, to the mutual satisfaction of adjoining 
 proprietors. 
 
 1323. Establishing New Boundaries. — Where the 
 description and map show a boundary to be a straight line 
 and the actual boundary is found to be crooked, it is a good 
 policy to establish a new and straight boundary by the prin- 
 ciple of "give and take," providing adjoining owners will 
 agree to the adjustment. 
 
 Fig. 314 illustrates the principle which is frequently em- 
 ployed in correcting such boundaries. 
 
 M^ D 
 
 c 
 
 Fig. 314. 
 Let A and E be two corners and let the boundary line 
 joining them be described and shown in the map as a straight 
 
LAND SURVEYING. 713 
 
 line. Let the irregular line A B CD £' represent the actual 
 boundary. It is evident that the dotted straight line A E 
 may be substituted for the irregular line A B C D E, and 
 would equitably divide the adjoining properties. The prin- 
 ciple of give and take is applied, the adjoining owners ma- 
 king exchanges .of equal areas. 
 
 The location of the new boundary is determined by ma- 
 king a careful survey of the old boundary and platting it to a 
 large scale; a fine thread is then stretched on the plat and a 
 line of division made as closely as may be estimated by the 
 eye. The areas of the equalizing triangles are then calcu- 
 lated by scaling their dimensions, and if they do not balance 
 the dividing line can readily be shifted until the desired 
 result is obtained. The line is then measured on the ground 
 and permanent corners established. Where the boundary 
 is in woodland, careful search must be made for line and 
 bearing trees. Blaze marks are very enduring, being easily 
 recognized on some varieties of trees after a lapse of a 
 quarter of a century. 
 
 1324. Lost and Obliterated Corners. — Corner 
 monuments of perishable material, such as wooden posts, 
 decay and in time become obliterated. A pile of stones, 
 which is commonly used as a corner, may become scattered, 
 and, unless permanent witnesses remain, it may be a difficult 
 matter to restore the landmark. The most enduring wit- 
 nesses are live trees which are disposed as shown in Fig. 315. 
 
 Three trees facing the corner are chosen ; in each tree 
 three notches are cut in the side facing the corner, and the 
 bearing and distance from each to the corner are recorded in 
 the notes. A sketch is made in the note book giving the 
 relative positions of the corner and the witness trees. When 
 the corner is lost, but the witness trees still remain, the cor- 
 ner is restored by describing intersecting arcs from the wit- 
 ness trees as centers with radii equal to the given distances 
 from the original corner. Where both corner and witnesses 
 are gone, it is best to run from both directions towards the 
 missing corner, placing the corner at the intersection of the 
 
714 
 
 LAND SURVEYING. 
 
 lines. The surveyor need not expect to find his measure- 
 ments agree with those in original surveys, but he can save 
 his successor much annoyance and trouble by careful and 
 accurate work. He should always give both in map and in 
 description the exact date of the survey; the direction of 
 
 Fig. 315. 
 
 courses should also be given both in writing and figures, and 
 the corners should be fully described. A stone monument 
 is the best corner, and should always be used where the 
 material is available. 
 
 AREAS. 
 1325. The area of a surface is its superficial content. 
 In the surveying of public lands all measurements are made 
 with the surveyor's chain, commonly known as Gunter's 
 chain, from the name of the inventor. It is GO feet in length 
 and contains 100 links, each 7.92 inches long. At each 
 interval of ten links a brass tag is attached with tally points 
 similar to those on the engineer's chain described in Art. 
 1214. Tables of surveyor's linear and square measure are 
 given in Arts. 209 and 211. For land areas the unit of 
 measurement is the square foot = 144 square inches, though 
 
LAND SURVEYING. 715 
 
 areas of considerable extent are usually expressed in acres. 
 An acre contains 43,500 square feet of surface. Rectangular 
 areas are determined by multiplying the length in feet by 
 the breadth in feet, and dividing the product by 43,500, 
 which gives the area in acres. 
 
 In surveys of farms or larger tracts, dimensions are given 
 in chains and links. The product of such dimensions is in 
 square chains, which, divided by 10 (the number of square 
 chains in an acre), gives the area in acres. 
 
 Example. — A rectangular piece of land is 1,060 feet in length by 
 820 feet in breadth ; required, the area. 
 
 Solution.— 1,060 x 820 = 869,200 sq. ft. 869,200 -h 43,560 = 19.954 
 acres. Ans. 
 
 DIFFERENT METHODS OF COMPUTING AREAS. 
 
 1326. By Dividing the Plat into Triangles.— 
 
 Farms, especially in the older States of the Union, are com- 
 monly of irregular form. The readiest and — where the 
 measurements have been accurately made — a sufficiently 
 accurate method of determining areas is as follows : Make 
 an accurate plat of the tract to as large a scale as may be 
 conveniently used. Divide the resulting figure, an irregular 
 polygon, into triangles, making their sides of as nearly equal 
 length as possible. It is evident that the sum of the areas 
 of the several triangles into which the polygon is divided is 
 equivalent to the area of the polygon. This mode of calcu- 
 lating area is illustrated in Fig. 316. 
 
 Let the irregular polygon A B C D E Fhe the outline of 
 a tract of land the area of which is required. Draw the 
 diagonals B F, C F, and C E, dividing the figure into four 
 triangles, the combined area of which is equal to the area of 
 the polygon. From the vertexes A, B, D, and E drop the 
 perpendiculars A G, B //, D K, and E L upon the opposite 
 bases of the triangles. The lengths of the several bases and 
 altitudes are measured with the scale and the areas of the 
 several triangles calculated by the rule : the area of a trian- 
 gle is equal to one-half the product of its base and altitude. 
 
71G 
 
 LAND SURVEYING. 
 
 The sum of the areas of the several triangles is equal to the 
 area of the polygon. 
 
 Fig. 316. 
 
 1327. By Dividing the Plat into Trapezoids. —A 
 
 plat of the area having been made, it may be resolved into 
 
 trapezoids by either of the methods shown in Figs. 317 and 
 318. In Fig. 317 the line A N is drawn parallel to B C, and 
 the lines B M, K H, and E L are drawn perpendicular to 
 A H, dividing the figure into trapezoids and the triangle 
 H D K. The area of each trapezoid is equal to one-half the 
 sum of its bases multiplied by its altitude, and the sum of 
 their areas together with the area of the triangle is equiva- 
 lent to the area of the polygon A B C D E F. In Fig. 318 
 a base line H Pis drawn, and from each angle of the polygon 
 perpendiculars are drawn to it. The sum of the areas of the 
 three trapezoids A B K H,B C N K, C D P N is found, and 
 
LAND SURVEYING. 
 
 717 
 
 from that sum, the sum of the areas of the trapezoids 
 A G L //, G F M L, F E O M, and E D P O \s subtracted. 
 The difference of these sums is the area of the polygon 
 A B C D E FG. 
 
 LATITUDES AND DEPARTURES. 
 
 1328. Definitions. — The latitude of a point is its 
 distance north or south of some '^parallel of latitndc" or 
 line running cast and lucst. The longitude of a point is its 
 distance east or west of some meridian or line running north 
 and south. 
 
 The meridian from which the longitude of a point is 
 reckoned is the magnetic meridian. 
 
 The distance which one end of a line is 
 due north or south of the other end is called 
 the latitude of that line. 
 
 The distance which one end of -a line is 
 due east or west of the other end is called 
 the departure of that line. 
 
 The latitude and departure of a line and 
 its determination are explained in Fig. 319. 
 Let A B he the given line whose length and 
 angle with the magnetic meridian A^ 5 is 
 known, and whose latitude and departure 
 are required. From B draw B C perpen- 
 dicular to N S^ forming the right-angled triangle A C B,'\x\. 
 which the sides C A and C B about the right angle are, re- 
 spectively, the latitude and the departure of the line A B. 
 Then, 
 
 A C ^=- A B y, cos bearing, and 
 B C ^ A B X sin bearing; 
 
 that is, the latitude is equal to the product of the cosine of 
 the bearing and the length of the course; and the departure 
 is equal to the product of the sine of the bearing and the 
 length of the course. 
 
 Let A />' = 400 feet and the bearing of A B, i. e., the 
 angle B A C= 30°. Then, latitude A C= co.) 30" X 400 = 
 
 Fig. 319. 
 
718 LAND SURVEYING. 
 
 .86G03 X 400 = 346.412 ft., and departure B C = sin 
 30° X 400 = .50000 X400 = 200 ft. 
 
 If the course be northerly, the latitude will be north, 
 marked + , and be additive; if southerly, it will be marked 
 — , and be subtractive. If the course be easterly the 
 departure will be east, marked +, and be additive; if 
 westerly, the departure will be west, marked—, and be 
 subtractive. 
 
 1329. Traverse Tables. — The latitude and departure 
 of any distance for any bearing can be found by a table 
 of natural sines and cosines, but for facilitating work 
 special tables, called traverse tables, have been prepared. 
 They usually give the latitude and departure for any bear- 
 ing to each quarter of a degree and for distances from 
 1 to 9. 
 
 To t(se the tables (see traverse tables, or Latitudes and 
 Departures of Courses), find the number of degrees in the 
 bearing in the left-hand column if the bearing be less than 
 45°, and in the right-hand column if the bearing be greater 
 than 45°. The numbers on the same line running across 
 the page are the latitudes and departures for that bearing 
 and for the respective distances, 1, 2, 3, 4, 5, 6, 7, 8, 9, 
 which appear at the top and bottom of the pages, and which 
 may be taken to represent links, rods, feet, chains, or any 
 other unit. Thus, if the bearing be 10° and the distance 
 4, the latitude will be 3.939 and the departure .G95; with 
 the same bearing, and the distance 8, the latitude will be 
 7.878 and the departure 1.389, or double the latitude and 
 departure for the distance 4. Any distance, however great, 
 can have its latitude and departure readily obtained from 
 this table, since, for the same bearing, the latitude and 
 departure are directly proportional to the distance because 
 of the similar triangles which they form. Hence, the lati- 
 tude and departure for 80 is ten times the latitude and 
 departure for 8, and is found by moving the decimal point 
 one place to the right; that for 500 is 100 times the latitude 
 and departure for 5, and is found by moving the decimal 
 
LAND SURVEYING. 719 
 
 point two places to the right, and so on. By moving the decimal 
 point one, two, or more places to the right the latitude and 
 departure may be found for any multiple of any number 
 given in the table. In finding the latitude and departure 
 for any number such as 453, the number is resolved into 
 three numbers, viz.: 40 and the latitude and departure 
 
 5 for each taken from the table 
 3 and then added together. 
 
 453 
 
 We thus obtain the following 
 
 Rule.— Write dozvn the latitude and departure, neglecting 
 the decimal points, for the first figure of tJie given distance; 
 write under them the latitude and departure for the second 
 figure, setting them one place further to the right; under 
 these place the latitude and departure for the third figure, 
 setting them one place still further to the right, and so 
 continue until all the figures of the given distance have been 
 used ; add these latitudes and departures and point off on the 
 right of their sums a ?iumber of decimal places equal to the 
 number of decimal places to which the tables being used are 
 carried; the resulting numbers will be the latitude and de- 
 parture of the given distance in feet, links, chains, or whatever 
 unit of measurement is adopted. 
 
 Example. — A bearing is 16° and the distance 725; what is the lati- 
 tude and departure ? 
 
 Distances. Latitudes. Departures. 
 
 700 6729 1929 
 
 20 1923 0551 
 
 5 . 4806 1378 
 
 725 6 9 6.936 199.788 
 
 Solution. — Taking the nearest whole numbers and rejecting the 
 decimals, we find the latitude and departure to be 697 and 200. 
 
 When a occurs in the given number the next figure must 
 be set two places to the right, as in the following example: 
 
 Example. — The bearing is 22° and the distance 907 feet; required, 
 the latitude and departure. 
 
730 
 
 LAND SURVEYING. 
 
 Solution. — 
 
 
 
 Distances. 
 
 Latitudes. 
 
 Departures. 
 
 900 
 
 8 34 5 
 
 3371 
 
 7 
 
 6490 
 
 2 622 
 
 907 
 
 840.990 
 
 3 3 9.722 
 
 Here the place of in both the distance column and in the latitude 
 and departure columns is occupied by a dash — . Rejecting the deci- 
 mals, the latitude is 841 feet 
 ^■"' and the departure 340 feet. 
 
 When the bearing is more 
 than 4~)°, the names of the 
 columns must be read from 
 the bottom of the page. The 
 latitude of any bearing, as 
 60°, is the departure of its 
 complement, 30'; and the 
 departure of any bearing, as 
 30°, is the latitude of its 
 complement, 60\ This will 
 be readily understood from 
 an inspection of Fig. 320, in 
 which if A' 5 be the mag- 
 netic meridian and BOA = 60^ the bearing, then A O \s the latitude 
 and A B the departure. If, now, 6> C be made the meridian and 
 i? 0(7 =30° (the complement of BOA) the bearing, then O C (the 
 equal of A B) is the latitude, and B C (the equal of A O) the departure. 
 
 Example. — Let O B = 1,326 feet, and its bearing = 60°. 
 Solution. — 
 
 Distances. Latitudes. Departures. 
 
 1,000 0500 0866 
 
 300 1500 2598 
 
 20 1000 1732 
 
 6 3 00 5196 
 
 1326 
 
 Fig. 330. 
 
 663.000 
 
 1148.316 
 
 of 
 and 
 
 The required latitude is 663 feet and the departure 1,148 feet. 
 
 Where the bearings are given in smaller fractions 
 degrees than is found in the table, the latitudes 
 departures can be found by interpolation. 
 
 Traverse tables are chiefly employed in testing the accuracy 
 of surveys, platting them, and calculating their content. 
 
 1330. Testing a Survey. — When a surveyor has 
 completed the survey of a field or farm by taking bearings 
 
LAND SURVEYING. 
 
 721 
 
 and measuring courses, it is evident that he has gone as far 
 north as south and as far east as west. The sum of the 
 north latitudes shows how far north he has gone, and the 
 sum of the south latitudes shows how far south he has gone. 
 The sum of the east departures shows how far east he has 
 gone, and the sum of the west departures shows how far west 
 he has gone. Hence, if the survey has been correctly made 
 these sums will be equal or will balance. 
 
 The entire operation of testing a survey is illustrated in 
 the following example: 
 
 
 
 
 Latitudes 
 
 Departures. 
 
 
 
 
 
 
 
 
 
 N + 
 
 S - 
 
 E + 
 
 w - 
 
 1 
 
 N 34i°E 
 
 273 
 
 226 
 
 
 154 
 
 
 2 
 
 N 35i° E 
 
 128 
 
 10 
 
 
 128 
 
 , 
 
 3 
 
 S 56i° E 
 
 220 
 
 
 121 
 
 184 
 
 
 4 
 
 S 34i° W 
 
 353 
 
 
 292 
 
 
 199 
 
 5 
 
 N56i" W 
 
 320 
 
 177 
 
 
 
 267 
 
 34r 
 
 273 
 
 56r 
 220 
 
 413 
 
 5786 
 2480 
 
 112 6 
 3940 
 1 68J 
 
 225.640 153.688 
 
 1097 
 1097 
 
 12 0.6 7 
 
 1673 
 1673 
 
 184.03 
 
 5 6i° 
 320 
 
 1656 
 
 1104 
 
 176.64 
 
 413 
 
 35r 
 
 128 
 
 34r 
 
 353* 
 
 2502 
 166! 
 
 466. 
 
 0079 
 0157 
 0621 
 
 266.88 
 
 466 
 
 0997 
 1994 
 7975 
 
 10.098 12 7.615 
 
 2480 • 1688 
 4133 2814 
 
 2480 1681 
 
 291.810 198.628 
 
 Adding up the north and south latitudes we find them to 
 exactly balance each other, as do the east and west departures, 
 which proves the survey to be correct. On account of the 
 inherent defects of the compass and the errors which are 
 
7%2 
 
 LAND SURVEYING. 
 
 liable to occur in measurement, especially on rough and 
 extensive areas, it is but rarely that the survey will exactly 
 balance. A moderate discrepancy, which would indicate 
 what may be called unavoidable errors, will be allowable, 
 and the survey accepted as correct. How great a difference 
 in the sums of the columns may be allowed is a doubtful 
 question. Every surveyor of experience knows the average 
 degree of accuracy of his work, and will readily distinguish 
 between a serious error and an allowable inaccuracy. 
 
 1331. Balancing a Survey. — When the sums of the 
 latitudes and of the departures do not equal each other, and 
 yet the difference does not indicate any error, the different 
 latitudes and departures are modified so that their sums 
 shall be equal. This process is called balancing the survey. 
 
 The error is distributed among the different courses in 
 proportion to their length by the following 
 
 Rule. — As the sum of all the courses is to any separate 
 course^ so is the ivJiole difference in latitude to the correction 
 for that course. A similar proportion corrects the departures. 
 
 An example illustrating the process of balancing a survey 
 is given below. In this example four separate columns are 
 given for the corrected latitudes and departures. In prac- 
 tice, however, the corrected latitudes and departures are 
 written in red ink directly above the original ones, which 
 are crossed out with red ink. The distances given are in 
 chains: 
 
 sta- 
 tions. 
 
 Bearings. 
 
 Dis- 
 tances. 
 
 Latitudes. 
 
 De- 
 partures. 
 
 Corrected 
 Latitudes. 
 
 Corrected 
 
 De- 
 partures. 
 
 
 N + 
 
 S- 
 
 E + 
 
 W- 
 
 N-f-l S- 
 
 E-l- 
 
 W - 
 
 1 
 2 
 
 3 
 4 
 
 N 53° E 
 S 29rE 
 S 31f ° W 
 N 61= W 
 
 10.63 
 4.10 
 7.69 
 7.13 
 
 6.54 
 3.46 
 
 3.56 
 6.54 
 
 8.38 
 2.03 
 
 4.05 
 6.24 
 
 6.58 
 3.48 
 
 3.55 
 6.51 
 
 8.;m 
 
 2.01 
 
 4.08 
 6.27 
 
 
 
 29.55 
 
 10.00 
 
 10.10 
 
 10.41 
 
 10.29 
 
 10.06 
 
 10.06 
 
 10.35 
 
 10.35 
 
LAND SURVEYING. 
 
 723 
 
 The corrections are made by the following proportions; 
 
 
 For Latitudes. 
 
 For Departures. 
 
 29.55 
 
 . 10.63:: 10 : 4 links. 
 
 29.55 : 
 
 10.63:: 12 : 4 links. 
 
 29.55 
 
 4.10:: 10: 1 link. 
 
 29.55 
 
 4.10:: 12 : 2 links. 
 
 29.55 
 
 7.69:: 10 : Slinks. 
 
 29.55 • 
 
 7. 69:: 12: Slinks. 
 
 29.55 
 
 : 7.13::10:2 1inks. 
 
 29.55 
 
 7.13:: 12: 3 links. 
 
 10 12 
 
 This rule should not always be strictly followed, especially 
 if one line has been measured over rough and broken coun- 
 try, while the others have been measured over smooth and 
 open ground. In such a case the greater part of the error 
 will probably lie in the rough line, and, consequently, it 
 should receive the larger share of the correction. A slight 
 alteration of a bearing will sometimes balance a survey. 
 This may be done where an obstructed sight has probably 
 caused an error in the bearing. 
 
 1332. Application of Latitudes and Departures 
 to Platting. — Rule three columns, one for stations, the 
 next for total latitudes, and the third for total departures, 
 as shown in the following diagram. 
 
 To obtain the total latitudes, begin at any station, the 
 extreme east or west one is preferable, and add up algebra- 
 ically the latitudes of the following stations, observing that 
 north latitudes are plus (+)» and south latitudes minus ( — ). 
 In the same manner find the algebraic sum of the depar- 
 tures for the different stations, placing each successive sum 
 opposite its proper station. 
 
 In the example given in Art. 1330, beginning at Station 
 1, we obtain the fol- 
 lowing results. 
 
 The work is proved 
 to be correct by the 
 latitudes and depar- 
 tures for Station 1 
 coming out equal to 
 0. To apply these 
 total latitudes and de- 
 partures in platting, 
 
 Stations. 
 
 Total Latitudes 
 from Station 1. 
 
 Total Departures 
 from Station 1. 
 
 1 
 
 0.00 
 
 0.00 
 
 2 
 
 + 2.26 
 
 + 1.54 
 
 3 
 
 + 2.36 
 
 + 2.82 
 
 4 
 
 + 1.15 
 
 + 4.66 
 
 5 
 
 -1.77 
 
 + 2.67 
 
 1 
 
 0.00 
 
 0.00 
 
7U 
 
 LAND SURVEYING. 
 
 we draw a meridian through the point taken as Station 1, 
 Fig. 321. Scale off from Station 1 upwards on this meridian 
 the latitude 2.26 chains to A and to the right from A, and 
 perpendicularly lay off the departure 1.54 chains to Station 
 2. Join 1-3. From 1 again lay off the latitude 2.3G ( = 
 2.26 + 10) chains to B, and to the right perpendicularly 
 the departure 2.82 (= 1.54 + 1.28) chains to Station 3. 
 Join 2-3, and proceed in like manner to locate Stations 
 
 Fig. 321. 
 
 .^ and S, laying off + latitudes above Station 1 and + 
 departures to the right of the meridian, and — latitudes 
 below Station 1 and — departures to the left of the merid- 
 ian. The principal advantages of this mode of platting 
 are rapidity of work, the fact that each course is platted 
 independently, and the certainty of the plats closing, pro- 
 vided the latitudes and departures have previously been 
 balanced. 
 
 1333. Calculating the Content.— The survey of a 
 field or farm having been made and platted, the content can 
 always be found by dividing the plat into triangles, and 
 
LAND SURVEYING. 
 
 725 
 
 scaling off their bases and perpendiculars from which the 
 contents are calculated. This and other methods previously 
 mentioned are only approximate, the degree of accuracy 
 depending upon the largeness of the scale and the skill of 
 the draftsman. The method of calculating content by 
 latitudes and departures is perfectly accurate, and does not 
 require the previous preparation of a plat. 
 
 1334. Definitions. — If a meridian be passed through 
 the extreme east or west corner of a field, the perpendicular 
 distance from any station to that meridian is the longitude 
 of that station, additive or plus if east and subtractive or 
 
 Fig. 322. 
 
 minus if west. The distance of the middle point of any line, 
 such as the side of the field, from the meridian is called the 
 longitude of that side. The difference of the longitudes 
 of the two ends of a line is called the departure of the line; 
 the difference of the latitudes of the two ends of a line is 
 called the Uititude of the line. 
 
72G LAND SURVEYING. 
 
 1335. Longitudes.— Let N S, Fig. 322, be the 
 
 meridian passing through the extreme westerly station of 
 the field A B C D E. From the middle and ends of each 
 side draw perpendiculars to the meridian. These perpendicu- 
 lars will be the longitudes and departures of the respective 
 sides. The longitude F G of the first course A B is evi- 
 dently equal to one-half its departure H B. The longitude 
 / K of the second course B C '\'& equal to J L -\- L M -\- M K 
 equal to the longitude of the first course plus half the de- 
 parture of the first course plus half the departure of the 
 course itself. The longitude F^of some other course E A, 
 taken anywhere, is equal to IV X — V X— U V, or equal 
 to the longitude of the preceding course minus half the de- 
 parture of that course minus half the departure of the course 
 itself, i. e., equal to the algebraic sum of these three parts, 
 remembering that south latitudes and west longitudes are 
 negative, and, therefore, to be subtracted when the 
 instructions are to make an algebraic addition. 
 
 To avoid fractions, the preceding expressions are doubled, 
 whence we deduce the following 
 
 Rule for Double Longitudes : 
 
 The double longitude of the first course is equal to its 
 departure. 
 
 The double longitude of the second course is equal to the 
 double longitude of t lie first course plus the departure of that 
 course plus the departure of the second course. 
 
 The double longitude of the third course is equal to the 
 double longitude of the second course plus the departure of 
 that course plus the departure of the course itself. 
 
 The double longitude of any course is equal to the double 
 longitude of the prcccditig course plus the departure of that 
 course plus the departure of the course itself. 
 
 The double longitude of the last course {as well as of the 
 first) is equal to its departure. This result, when obtained by 
 the above rule, proves the accuracy of the calculation of the 
 double longitudes of all the preceding courses. 
 
LAND SURVEYING. 
 
 727 
 
 Fig. 323. 
 
 it is equal to the product 
 
 1 336. Areas. — The following is an application of the 
 rule for finding areas by double longitudes. See Fig. 323. 
 Let A B Ch& 2l three-sided field, 
 of which A is the most westerly- 
 station. Through A draw a 
 meridian, and from the stations 
 B and C and the middle points 
 of the three sides of the field 
 draw perpendiculars to the 
 meridian. It is evident that the 
 area of the field A B C is equal 
 to the area of the trapezoid 
 D B C E less the triangles 
 A D B zxi6.A E C. The area of 
 the triangle A D B \s equal to 
 the product oi A Dhy F G, i. e. 
 of the latitude of the first course by its longitude. The area 
 of the trapezoid D B C E is equal to the product oi D E hy 
 half the sum oi D B and E C, or H K, i. e., it is equal to the 
 product of the latitude of the second course by its longitude. 
 The area of the triangle A E C is equal to the product oi A E 
 by half E C, ov L M, i. e. , it is equal to the product of the 
 latitude of the third course by its longitude. The bearing 
 of the course A Bis^ E, and that of C^i is N W. Their 
 latitudes are, therefore, north. The bearing of the course 
 .5 C is S E, and its latitude is south. Calling the products 
 in which the latitude is north, north products, and the 
 products in which the latitude is south, south products, we 
 find the area of the trapezoid to be a south product and the 
 areas of the triangles to be north products. The difference 
 of the north products and the south prodifcts is, therefore, 
 the area of the three-sided field ABC. 
 
 Using double longitudes, to avoid fractions, in each of 
 the preceding products, their difference will be double the 
 area of the field ABC. 
 
 Take, now, a four-sided field, A B C D, Fig. 324, and 
 drawing a meridian through its most westerly station A, 
 
728 
 
 LAND SURVEYING. 
 
 and longitudes as in the preceding case, it will be evident 
 from inspection that the area of the field A B C D is equal 
 to the trapezoid F C D G, diminished by the area of tri- 
 angles A G D, A E B, and 
 the trapezoid E B C F. 
 The area of the triangle 
 A E B is equal to the 
 product of the latitude 
 A E of the first course by 
 its longitude H K. Its 
 product is north. The area 
 of the trapezoid E B C F 
 is equal to the product of 
 the latitude E F of the 
 second course by its longi- 
 tude L M, and is also :i 
 north product. The area 
 of the trapezoid F C D G 
 is equal to the product of 
 the latitude F G oi the 
 third course by its longi- 
 tude N (9, a south product. 
 The area of the triangle 
 A G D'\s equal to the prod- 
 uct of the latitude A G oi the fourth course by its longi- 
 tude P Q, a north product. Subtracting the sum of the 
 north products from the sum of the south products the 
 difference is the area of the field A B C D. If double longi- 
 tudes had been used, as in the previous case, the difference 
 would have been double the area of the field. 
 
 Fig. 324 
 
 1337. The Application of I>oul>le Longitudes to 
 the FindinK of Areas. — Whatever the number or direc- 
 tions of the sides of a field or any surface enclosed by 
 straight lines, its area will always be equal to half the dif- 
 ference of the north and south products arising from multi- 
 plying together the latitude and double longitude of each 
 course or side, whence the following 
 
LAND SURVEYING. ' 729 
 
 General Rule for Finding Areas : 
 
 1. Prepare ten columns, headed as in the following exam- 
 ples, and in the first three write the stations, bearings, 
 and distances. 
 
 2. Find the latitudes and departures of each course by the 
 traverse table, as directed in A rt. 1329, placing them in the 
 four following columns. 
 
 3. Balance them as in Art. 1331, correcting them in red 
 ink. 
 
 If. Fifid the double longitudes as in Art. 1335, zvitJi refer- 
 ence to a meridian passing through the extreme east or west 
 station, and place them in the eighth column. 
 
 5. Multiply the double longitude of each course by the 
 corrected latitude of that course, placing the north prod- 
 ucts in the nintli column and the south products in the tenth 
 column. 
 
 6. Add the last two columns ; subtract the smaller sum 
 from the larger, and divide the difference by two. The 
 quotient will be the content required. 
 
 1338. To Find the Most Easterly or Westerly 
 Station of a Survey. — Make a rough hand sketch of the 
 tract, giving the sides, their approximately true direction, and 
 length. The most easterly or westerly station may then be 
 determined from an inspection of the sketch. 
 
 Example 1 of this article refers to the five-sided field, a 
 plat of which is given in Fig. 321, and the latitudes and de- 
 partures of which were calculated in Art. 1330. Station 
 1 is the most westerly in the plat, and the meridian will be 
 passed through it. 
 
 The double longitudes are found by applying the rule for 
 double longitudes, given in Art. 1335. As the additions 
 are made algebraically, due attention must be paid to the 
 signs. The double longitudes are marked D. L., as shown in 
 the marginal diagram. These double longitudes are ob- 
 tained by the following operation. As stated in- the rule, 
 the double longitude of the first course is equal to the 
 
730 
 
 LAND SURVEYING. 
 
 stations. 
 
 D. L. 
 
 1 
 
 + 1.54D.L. 
 + 1.54 
 + 1.28 
 
 2 
 
 + 4.36D.L. 
 
 + 1.28 
 + 1.84 
 
 3 
 
 + 7.48D.L. 
 + 1.84 
 -1.99 
 
 4 
 
 + 7.33D.L. 
 
 -1.99 
 
 -2.67 
 
 5 
 
 + 2.67D.L. 
 
 departure. By reference to the given example, we find 
 that the departure of the first course is 
 1.54 chains, an cast departure, and, there- 
 fore, positive. We record this in the 
 column headed D. L., opposite Station 1. 
 The D. L. of the second course is equal 
 to the D. L. of the first course plus the 
 departure of that course plus the de- 
 parture of the second course. Accord- 
 ingly, we place under the D. L. of the 
 first course, the departure of that course, 
 viz., + 1.54, and the departure of the 
 second course, viz., + 1-28, as given in 
 the east departure column of the exam- 
 ple. This sum, viz., -|-4.36 is the D. L. 
 of the second course and placed opposite 
 Station 2. The D. L. of the third course 
 is equal to the D. L. of the second course 
 plus the departure of that course plus the departure of 
 the third course. Accordingly, we place under the D. L. 
 of the second course the departure of that course, 
 viz., + 1.28, and the departure of the third course, viz., 
 + 1.84. This sum, + 7.48, is the D. L. of the third course, 
 which we place opposite Station 3. In a similar manner 
 we find the D. L. for the fourth and fifth courses. The 
 double longitude of the last course is equal to its de- 
 parture, which proves the work. The double longitudes of 
 the courses are then multiplied by their corresponding lati- 
 tudes, and the content of the field obtained as directed in 
 the given rule. 
 
 Had the meridian been supposed to pass through Station 
 Jt, the most easterly station, all the longitudes would have 
 been west or minus, but the difference in the double areas 
 would have been the same, giving the same content as 
 before. 
 
 The following examples will give the student some prac- 
 tice in the use of traverse tables, and in applying latitudes 
 and departures in the calculation of areas: 
 
LAND SURVEYING. 
 
 731 
 
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 LAND SURVEYING. 
 
 
 
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LAND SURVEYING. 
 
 733 
 
 The notes of the survey given in Example 3 
 by total latitudes and total 
 departures from Station 1. 
 A plat of the survey is given 
 in Fig. 325 and the total lati- 
 tudes and departures in the 
 accompanying table. From 
 an inspection of the plat it 
 will be seen that Station 2 is 
 the most easterly, and the 
 double longitudes given in 
 Example 3 are reckoned from 
 a meridian passing through 
 that station. 
 
 are platted 
 
 
 Total 
 
 Total 
 
 Stations. 
 
 Latitudes 
 from 
 
 Departures 
 from 
 
 
 station 1 . 
 
 station 1. 
 
 1 
 
 0.00 
 
 0.00 
 
 2 
 
 -3.13 
 
 "t- 4.85 
 
 3 
 
 -4.94 
 
 + 3.52 
 
 4 
 
 -5.71 
 
 + 2.89 
 
 5 
 
 -6.06 
 
 + 1.91 
 
 6 
 
 -5.61 
 
 + .76 
 
 ■ 7 
 
 -4.39 
 
 -1.06 
 
 8 
 
 -3.51 
 
 - .48 
 
 9 
 
 -2.66 
 
 -1.76 
 
 1 
 
 -0.00 
 
 0.00 
 
 Fig. 325. 
 
 TOWN SITES AND SUBDIVISIONS. 
 
 1339. First Considerations. — In laying out town 
 
 sites the consideration of first importance is the location of 
 
 the streets rather than the greatest number of lots obtainable. 
 
 The custom of laying out town sites in rectangular lines, 
 
734 LAND SURVEYING. 
 
 without reference to topographical conditions, prevails 
 almost universally throughout the United States. This is 
 largely owing to two principal causes, viz., first, the sup- 
 position that the rectangular method or plan will yield the 
 greater number of lots, and, hence, the greater profit, and, 
 second, the haste in surveying, platting, and placing the 
 property on the market does not admit of a thorough study 
 of the ground. 
 
 The town site should be considered as a whole, the loca- 
 tion of its main streets and thoroughfares being determined 
 by traffic considerations chiefly. These considerations will 
 necessarily involve the questions of grades, drainage, and 
 railway communications. Without the latter there is small 
 excuse for a town. Where possible a main avenue should be 
 laid Qut, parallel with the railroad, leaving one tier of lots 
 between the street and track. This avenue may then be used 
 as a base from which to lay out the adjoining streets and 
 avenues, which may be parallel with and at right angles to 
 it if the surface be generally level, or at oblique angles if 
 the surface be rolling or hilly. 
 
 1340. Grades, Drainage, and Topography. — 
 
 Grades and drainage should be so arranged that surface 
 water will tend to form main channels, i. e., the surface 
 water of several streets will find its way into some particular 
 street where special provision can be made for its control 
 and discharge. 
 
 The streets in the residential portion of the town should, 
 so far as possible, conform to the existing topographical con- 
 ditions. This will greatly reduce the cost of grading the 
 streets, give easy grades, and so promote comfort of pedes- 
 trians and the efficiency of teams. There is no loss in front- 
 age from the employment of curves instead of straight lines, 
 and there is no question of the advantage of the former 
 from an artistic standpoint. 
 
 The accompanying plan, Fig. 326, is made to meet the 
 following conditions, viz., two lines of railroad, a main line 
 and branch, meet at the junction of two streams. The land 
 
LAND SURVEYING. 
 
 735 
 
 bordering on the smaller stream, which is followed by the 
 branch road, rises rapidly from the stream, reaching a height 
 of 200 feet, and then falls gradually until an elevation of 50 
 feet above the stream is reached, when the surface remains 
 generally level. The land bordering the larger stream, which 
 is followed by the main line of the railroad, rises gradually 
 until a height of 50 feet above the stream is reached, beyond 
 which the surface is generally level. 
 
 1 
 
 ^^Pj 
 
 ^ 
 
 
 
 / 
 
 1 
 
 i 
 
 ' L 
 ■a " 
 
 if 
 
 — 1» 
 1 
 
 I 
 
 -l'^ 
 
 
 
 
 90' 
 
 
 t 
 
 i 
 
 1 
 
 '230' 
 
 • 
 
 .._t_ 
 
 
 
 Avert 
 
 lOO' 
 
 
 
 
 
 Fig. 326. 
 
 That part of the given surface which is generally level 
 will be laid out in rectangular blocks. The unaided eye will 
 readily determine whether a town site is well adapted to 
 rectangular divisions. If it is so adapted the order of survey 
 will be as follows: 
 
 1341. General Directions for Preliminary Sur- 
 vey. — Run a line enclosing the entire area, giving location 
 of prominent features, such as railroads, highways, streams. 
 
736 LAND SURVEYING. 
 
 houses, etc., and accurately plat to a scale of 200 feet to the 
 inch. For cities, avenues are made 100 feet in width be- 
 tween building lines, and streets 60 feet, the avenues being 
 parallel to each other and the streets at right angles to the 
 avenues. City lots usually have fronts of 25 feet and depths 
 of 125 feet. Part of New York is laid out in blocks of 200 
 feet by 800 feet, the 200 feet facing the avenues. Lots are 100 
 feet in depth, each block containing 64 lots. Having deter- 
 mined the dimensions of the streets and blocks, lay out the 
 principal base line so that it will form the center line of a 
 street or avenue running parallel with the general direction 
 of the railroad, providing for overhead or sub-crossings 
 where practicable. If crossings must be at grade, the fewer 
 of them the better. Provide easy and safe access to railroad 
 stations and freight depots. 
 
 Lay out the plat in rectangular blocks, accurately scaling 
 all dimensions. Arrange the plan so as to interfere as little 
 as possible with existing lines of travel, at the same time 
 giving due regard to the future needs of an increasing popula- 
 tion. If the ground is wooded or sight obstructed by under- 
 brush, but one additional base line can be used. It should 
 be about midway between the extremities of the principal 
 base line and at right angles to it. If, however, the ground 
 is open with nothing to interfere with long sights, two base 
 lines should be laid out, one at either extremity of the main 
 base and at right angles to it. 
 
 1342. Measurements. — All measurements should be 
 made with a standard steel tape and plumb-bob and care- 
 fully checked. The base lines especially should be measured 
 with great care, as the correctness of all the subsequent 
 measurements depends upon the degree of accuracy with 
 which these primary lines are measured. 
 
 1343. Base Lines and Subdivisions. — The rect- 
 angular method of surveying town sites is illustrated in 
 Fig. 327, in which A B is the principal base, and the aux- 
 iliary bases A D and B C are laid off from the extremities 
 of A B. The avenues are at right angles to A B, and the 
 
LAND SURVEYING. 737 
 
 streets parallel to A B. Avenue A is parallel to the railroad, 
 
 90 
 
 Ti \V \ W 
 
 o— o— o * o-^o 
 
 A E O T 
 
 Fig. 327. 
 
 or 
 
 from which it is separated by a 25-foot alleyway and one 
 tier of lots 125 feet deep. Avenues are 100 feet in width, 
 
738 LAND SURVEYING. 
 
 streets GO; blocks 250 feet by GOO feet, fronting 250 feet on 
 the avenues, and the lots are 25 feet by 125 feet. 
 
 The initial point A of the principal base A B is the center 
 of an avenue, and should be fixed by a plug 2' X 2' X 18' 
 driven flush with the surface of the ground and the center 
 marked by a tack, with a guard stake beside it, and num- 
 bered 0. Drive a temporary plug at X to be used as a fore- 
 sight in giving the direction of A B. Set up the instru- 
 ment at A and sight to X, frequently checking the foresight. 
 Measure from A ox\. A B b'd feet, and drive a 12' plug, care- 
 fully centering the same. This point marks the north side 
 of Avenue B. Continue measuring on the line A B, driving 
 a stake at each hundred feet, marking the exact measure- 
 ment by a tack, and number in .regular succession from A. 
 At G50 feet from A set a 12" plug with tack center, marking 
 the south side of Avenue C\ 50 feet further, at Station 7, 
 set a 12" plug with center. This point will be in the center 
 of Avenue C', at 7 -j- 50 a plug with center is set, marking 
 the north side of Avenue C. In like manner locate the 
 center and sides of all avenues lying between A and X, 
 always checking the foresight before setting tack centers. 
 At B set a plug 2' X 2' X 18". At each station remeasure 
 the last 100 feet, so as to secure accurate results. The measure- 
 ment of the main base line A B being completed, take a 
 foresight on Jfand turn off an angle of 90°, setting a tem- 
 porary plug at Y. Mark the center at Fwith a pencil point 
 and repeat the angle five times, marking a center at V for 
 each angular measurement. These points will vary slightly 
 in position, though two of them may fall at the same place. 
 Take the mean or average of these points, and mark the 
 point with a tack. Then, commencing at A measure the 
 line A V, setting stakes at each 100 feet, as in A B, and 
 set hubs on the side lines of Avenue A and at centers and 
 side lines of the streets parallel to it, checking the foresight 
 at V and the measurement of each station before setting 
 plug centers. On this line the measurements will be, first 
 50 feet, next 250, then GO, 250, GO, etc., the streets being 
 60 feet and the blocks 250 feet in width. At D set a plug 
 
LAND SURVEYING. 739 
 
 2' X 3* X 18", In a similar manner locate the base line B C 
 and the street centers and side lines on B C. Then set up 
 at D, which is a permanent point, and foresighting to C set 
 points on centers and sides of avenues on D C. Next set 
 up at £", foresighting to F. Provide a supply of plugs 
 1" X 1' X 8' and measure from E, 50 feet in both directions 
 on the line E F, and mark the points with pins. These 
 points will be on the north and south lines of Avenue B. 
 On either side of these pins in the line E F, and about two 
 feet from them, set plugs, leaving two inches of their length 
 above the surface of the ground. Center these plugs, dri- 
 ving tacks half their length into each one. In the same 
 manner set plugs on both sides of each street line as indi- 
 cated by the small circles in the figure. In this example 
 B C '\?> 2,800 feet distant from A D, too great a distance for 
 the accurate setting of plug centers; therefore, the measure- 
 ments from A D to B C should terminate on the south line 
 of Avenue D. In the same manner locate plugs on the lines 
 G H, I K, L M, etc. Having set all plugs between the 
 base A D and the south line of Avenue Z?, move the instru- 
 ment to F and, foresighting to E^ set plugs on both sides of 
 all avenues between Avenue /^and Avenue Z>, including the 
 north side of D. In like manner locate plugs on H G, K I, 
 ML, etc. Move the instrument to the point U; stretch 
 pieces of cord between the plugs on both sides of the line 
 X T; foresight to T, and at each intersection with the cord, 
 as at V, IV, etc., drive a 12" plug, and center with a tack. 
 This method of locating street corners by intersections has 
 the advantage of bringing all corners on the same street in 
 perfect line, a result which it would be practically impossible 
 to obtain by direct measurement. The measurement of all 
 angles is referred to the base lines where special care is 
 taken in checking them, 
 
 1344. Permanent Monuments. — The street and 
 avenue centers located on the base lines should always be 
 rendered permanent by setting stone monuments at those 
 points. 
 
MAPPING. 
 
 INTRODUCTION. 
 
 1345. The object of this section is to furnish the stu- 
 dent thorough, practical instruction in mapping. Having 
 previously mastered the section on Geometrical Drawing, 
 he should by this time be familiar with the various instru- 
 ments employed in the drafting room, and be accustomed 
 to their use. 
 
 All the principles and methods here described are fully il- 
 lustrated by drawings, which comprise six plates, found at 
 the end of the volume on Mechanical Drawing. These plates 
 the student will be required to draw, and the degree of pro- 
 ficiency, as shown by his work, will determine his standing. 
 The examples given in the plates are similar to those met 
 with in practical field and office work. 
 
 1346. A map is a series of lines and angles so com- 
 bined as to represent the true outlines, proportions, and 
 character of any required surface. 
 
 1347. Lines are either boundaries or divisions of 
 the required surface. They have only the properties of 
 direction and length. 
 
 DRAWING THE PLATES. 
 
 PLATE, TITLE: PLATTING ANGLES I. 
 
 1348. This plate contains six angle lines, three of which 
 are comprised by Fig. 1 and three by Fig. 2. The three 
 lines a, b, and c, under Fig. 1, will be drawn to a scale of 200 
 feet to the inch, platting the angles with a protractor, the 
 
742 
 
 MAPPING. 
 
 NOTES FOR LINE a. 
 
 use of which was fully explained in the section relating to 
 Geometrical Drawing. 
 
 The student will plat these lines according to the follow- 
 ing directions, being careful to give to each line approxi- 
 mately the same position it 
 occupies in the plate. This 
 statement also applies to all the 
 plates which are to be drawn 
 from the data given in thjs 
 section. In these examples, 
 distances are expressed in sta- 
 tions of 100 feet each, as in 
 the section on Surveying. The 
 direction of each line is referred 
 to that of the immediately pre- 
 ceding line, which line is pro- 
 duced and the angle recorded 
 as being to the right or left of 
 that line. In practical office work, the lines produced are 
 drawn lightly in pencil and erased as soon as the angles 
 are laid off. In the lines a and b, Fig. 1, the lines produced 
 are dotted and the angles written in dotted arcs, in order 
 that the student may clearly and fully understand the 
 method. The dimensions of the following plates and the di- 
 rections for drawing the border lines are the same as for the 
 plates on Geometrical Drawing. The notes for line a in 
 Fig. 1 are as shown. 
 
 Stations. 
 
 Angles. 
 
 25 + 84 
 
 End of Line. 
 
 21 + 94 
 
 L. 32° 35' 
 
 15 + 53 
 
 R. 44° 10' 
 
 11 + 72 
 
 L. 60° 30' 
 
 5 + 25 
 
 L. 25° 15' 
 
 
 
 
 1349. The starting point A of the line is numbered 0. 
 The first angle turned is at Sta. 5 + 25, which we denote by 
 B. Locating the starting point A about three-fourths of an 
 inch from the lower and left-hand border lines, we draw a 
 straight line, giving it the same direction as that given to it 
 in the engraving. Scale off from yi, to a scale of 200 feet to 
 the inch, the first course, 525 feet in length, locating the 
 point /)'. Produce A B to C, being sure to make B C a. 
 little greater than the diameter of the protractor. At Sta. 
 5 + 25, B, an angle of 25° 15' is turned to the left. Now, 
 
MAPPING. 743 
 
 placing the center of the protractor on the point B, with the 
 zero point on the line B C, lay off the angle 25'' 15' to the 
 left of/) C, marking the point of angle measurement /?with 
 a needle point. Through the points ^and Z>draw a straight 
 line. The angle C B D is 25° 15', and the line B D is the 
 direction of the next course. The second angle, 00° 30', is 
 turned to the left at Sta. 11 + 72. The length of the second 
 course is found by subtracting 525 from 1,172, giving a dif- 
 ference of 647 ft. Produce B D and scale off the second 
 course 647 ft., locating the point E2X Sta. 11 + 72. Produce 
 B Eto F, and lay off to the left oi E F the angle 60° 30', lo- 
 cating the point G. Join E and G. The angle /^£ 6" is 
 60° 30', and the line ^ 6^ is the direction of the next 
 course. 
 
 The third angle is R. 44° 10', and is turned at Sta. 15 + 53. 
 The length of the third course is found by subtracting 1,172 
 from 1,553, giving a difference of 381 feet. Produce E G 
 and scale off from E the distance 381 ft., locating the point 
 H at Sta. 15 + 53. Produce E H to K, and to the right of 
 H K lay off the given angle 44° 10', locating the point L. 
 The line joining the points H and L forms with // A'an angle 
 of 44° 10', and gives the direction of the next course. 
 The next angle is L. 32° 35', and is turned at Sta. 21 + 94. 
 The length of the course is found by subtracting 1,553 from 
 2,194, giving a difference of 641 ft. Produce H L and scale 
 off from // the distance 641 ft., locating the point M at 
 Sta. 21 4- 94. Produce H M to N, and to the left of M N 
 lay off the given angle 32° 35', locating the point O. 
 Draw M O. The angle N M O is 32° 35', and M O is 
 in the direction of the next and last course of line a^ 
 whose length is found by subtracting 2,194 from 2,584. 
 The difference is 390 ft. We produce the line M O, and 
 from M scale off the last course of 390 ft., locating the 
 point P at Sta. 25 + 84, At each angular point in the 
 line an arc is described, giving <he measurement of the 
 angle. 
 
 The student will in a similar manner plat the following 
 notes for the lines b and c. Fig. 1, of the same plate: 
 
744 MAPPING. 
 
 NOTES FOR LINE b. NOTES FOR LINE C 
 
 Stations. 
 
 Angles. 
 
 23 + 10 
 
 End of Line 
 
 10 + 35 
 
 R. 25° 10' 
 
 12 + 82 
 
 L. 15° 15' 
 
 8 + 50 
 
 L. 30° 40' 
 
 4 + 40 
 
 R. 15° 20' 
 
 
 
 
 Stations. 
 
 Angles. 
 
 28 + 60 
 
 End of Line 
 
 21 + 4G 
 
 R. 34° 30' 
 
 17 + 09 
 
 R. 53° 28' 
 
 11 + 9G 
 
 L. 25° 10' 
 
 5 + 33 
 
 R. 21° 10' 
 
 
 
 
 Fig. 328. 
 
 1 350. To Lay Off an Angle by Chords.— This is 
 done by means of a table of chords in which the lengths of 
 
 chords for all angles 
 from to 90° are 
 given in terms of a 
 radius 1. A radius 
 of any convenient 
 length may be as- 
 sumed, and the cor- 
 responding chord length obtained by multiplying the length 
 of the chord given in terms of radius 1 by the length of the 
 assumed radius. Thus, let it be required to lay off from a 
 given line an angle of 40° 10' to the left. Let A B, 
 Fig. 328, be the given line. Produce A B to C, making 
 B C= 400 ft., the length of the assumed radius. 
 
 From a table of chords, we find that the chord of an 
 angle of 40° 10' in terms of a radius 1 is .G8G8. Multiplying 
 this chord by 400 ft., the length of the assumed radius, we 
 have 274.72 ft., the length of the required chord. From B 
 as a center, with a radius B C = 400 ft., describe to the left 
 of B C the indefinite arc JC D, being sure that the length 
 of CD is slightly greater than the length of the required 
 chord, and from (T as a center, with a radius of 274.72 ft., 
 describe an arc intersecting the arc C D in C. Through 
 
MAPPING. 
 
 745 
 
 B and C draw a straight line. The angle C B C \% 
 40° 10', the required angle. This method of platting angles 
 is more accurate, though less rapid, than platting with a 
 protractor. 
 
 Note. — The table of chords used for the calculations given in this 
 Course may be found in Trautwine's Pocket Book, a very useful book 
 to all surveyors. If the student does not possess a copy, he may easily 
 find the required chord from his table of sines by multiplying the sine 
 
 40= 10' 
 of half the given angle by 2. Thus, the chord of 40° 10' = 3 sin — ^ — = 
 
 2 sin 20" 05 = 2 x. 34339 = 
 same as given in the table. 
 
 178 = .6868, using but four places, the 
 
 NOTES FOR LINE a. 
 
 1351. Fig. 2, same plate as above, contains three ex- 
 amples in the lines a, b, and c, in which the angles are laid 
 off by chords. The notes for example a are given in the 
 accompanying table. 
 
 The first course A B is 360 feet in length, which the stu- 
 dent will draw to a scale of 200 feet to the inch. The start- 
 ing point A is numbered 0, 
 and B, the end of the first 
 course, 3+60. At j5 an angle 
 of 30° 30' is laid off to the 
 right. Produce A B 400 feet, 
 which we assume to be the 
 length of the radius in calcu- 
 lating chord lengths for lay- 
 ing off angles, and locate the 
 point C. Then, from B as a 
 center, with a radius of 400 
 feet, describe the indefinite 
 arc C C on the right side of 
 the radius B C, being sure that the arc shall contain at least 
 30° 30'. We find in a table of chords that the chord of 
 30° 30' =.5261, which, multiplied by 400 ft., the length 
 of the assumed radius, gives 210.44 ft., the length of the 
 required chord. From C as a center, with a radius of 
 210.44 ft., describe an arc intersecting the arc C C in 
 the point E. A line joining B and E will form with the 
 radius B C 2in angle C B E = 30° 30', the required 
 
 Stations. 
 
 Angles. 
 
 25 + 80 
 
 End of Line 
 
 20+38 
 
 L. 37° 20' 
 
 15 + 18 
 
 L. 31° 08' 
 
 9 + 13 
 
 R. 39° 26' 
 
 3 + 60 
 
 R. 30° 30' 
 
 ' 
 
 
746 
 
 MAPPING. 
 
 angle. The next angle R. 39° 20' is turned at Sta. 9 + 13, 
 making the length of the second course 553 ft. Denote 
 Sta. 9+13 by F. Produce B F 400 ft. to G. From 
 F Sis a. center, with a radius F G oi 400 ft., describe to 
 the right oi F G the indefinite arc G G\ being sure 
 that the arc shall contain at least 39° 2G'. The chord of 
 39° 20' to a radius 1 is .0747, which, multiplied by 400 ft., 
 gives 209.88 ft., the length of the required chord. From F 
 as a center, with a radius of 209.88 ft., describe an arc in- 
 tersecting the arc G G' in H. A line joining F and // will 
 form with the radius F G the angle G F N = 39° 20', the 
 required angle. The next angle, viz.; L. 31° 08', is turned 
 
 NOTES FOR LINE b. 
 
 NOTES FOR LINE c. 
 
 Stations. 
 
 Angles. 
 
 22 + 40 
 
 End of Line. 
 
 10 + 50 
 
 L. 18° 20' 
 
 8 + 60 
 
 R. 25° 14' 
 
 3 + 25 
 
 R. 8° 10' 
 
 
 
 
 Stations. 
 
 Angles. 
 
 25 + 34 
 
 End of Line. 
 
 19 + 94 
 
 L. 51° 22' 
 
 14+81 
 
 R. 21° 20' 
 
 10+38 
 
 R. 39° 18' 
 
 4+13 
 
 L. 64° 30' 
 
 
 
 
 at Sta. 15 + 18, making the length of the third course 005 ft. 
 Call Sta. 15 + 18, A". Produce F K 400 ft. to L. From K 
 as a center, with a radius K L oi 400 ft., describe to the 
 left of K L the indefinite arc L M. The chord of 31° 08' is 
 .5307, which, multiplied by 400 ft., gives 214.08 ft., the length 
 of the required chord. From Z as a center, with a radius 
 of 214.08 ft., describe an arc intersecting the arc L M in 
 the point N. Join K and h\ forming with K L the angle 
 LK N- 31° 08'. The next angle, viz., L. 37° 20', is turned 
 at Sta. 20+38, making the length of the fourth course 
 520 ft. Call Sta. 20 + 38, O. Produce K O 400 ft. to P. 
 From 6> as a center, with a radius O P, describe the indefi- 
 
MAPPING. 
 
 747 
 
 nite arc P Q. The chord of 37° 20' is .6401, which, multi- 
 plied by 400 ft., gives 25G.04 ft., the length of the required 
 chord. From P as a center, with a radius of 256.04 ft., 
 describe an arc intersecting the arc P Q \n R. Join O and R, 
 forming with O P the angle P O R — 'iT 20'. The end of 
 the line 5 is at Sta. 25 + 80, making the length of the last 
 course 542 ft. In a similar manner, plat the notes for lines 
 b and c^ which are given in Art. 1353. 
 
 1352. To Lay Off an Angle by its Bearing.— By 
 
 this method of laying off angles, the direction of each line 
 is referred to the magnetic meridian, which maintains a con- 
 stant direction, being a north and south line. The bearing 
 of a line is the angle which the line makes with the magnetic 
 meridian. In platting a land or railroad survey, a pencil 
 
 kE rQ 
 
 Fig. 329. 
 
 line giving the direction of the magnetic meridian is drawn 
 through each station at which a bearing is taken. 
 
 The direction of the meridian may be given by means of 
 the ordinary T square and triangles, and the angles laid 
 off either by a protractor or by tangents. The use of T 
 square and triangles in laying off angles by bearings is illus- 
 trated in Fig. 329. A sheet of paper is fastened to a draw- 
 ing board. It is well known that if the head of the T square 
 
748 MAPPING. 
 
 be kept firmly pressed against the side of the drawing board, 
 as shown in the figure, the lines drawn along the straight 
 edge will be parallel; hence, the lines drawn perpendicular 
 to this straight edge by means of the triangles, as shown in 
 the figure, will be parallel. 
 
 Either the parallels drawn along the straight edge of the 
 T square or of the triangle may be used as the magnetic 
 meridian, though the latter is preferable, as it brings the 
 north end of the meridian at the top of the map, which is 
 its proper position. 
 
 Let* it be required to plat a line having a bearing of 
 N G0° E. As in Fig. 329, a point A is assumed as the station 
 at which the bearing is taken. Through the point A, a line 
 A B \?, drawn perpendicular to the straight edge of the T 
 square. This line will represent the direction of the mag- 
 netic meridian. As the bearing is east, the angle of 60° will 
 be to the right of A B. Place a protractor with its center 
 at A and its zero point in the line A B. Lay off the angle 
 60°, and mark the point of measurement C with a needle 
 point. Draw a line joining the starting point A with the 
 point of angle measurement C. The line A C will then 
 form an angle of 60°. with the meridian, and its course will 
 be N 60° E. From the notes find the length of the first 
 course, and measure on the line A C to some convenient 
 scale the length of that course, locating the point D, where 
 the next bearing N 30° E is taken. Slide the T square 
 upwards, and with the triangle draw through D another 
 meridian D E. From Z?as a center lay off from the right of 
 the meridian D E the bearing N 30° E. Let F mark the 
 measurement of this angle. The line joining D and F will 
 have a bearing of N 30° E. 
 
 PLATE, TITLE: PLATTING ANGLES IL 
 1353. This plate contains five angle lines, the angles of 
 the three lines given in Fig. 1 being platted by magnetic 
 bearings, and those in Fig. 2 by tangents. In Fig. 1, line «, 
 the distances are given in stations of 100 feet each ; in the 
 lines /^ and r, the distances are given in chains. The student 
 
MAPPING. 
 
 749 
 
 will draw line a to a scale of 200 feet to the inch, and lines d 
 and r to a scale of 2 chains to the inch. The notes of line 
 a are given below. 
 
 Let A be the starting point of the line, which we num- 
 ber Station 0. Let the arrow iV S give the direction of the 
 magnetic meridian. Through 
 A draw a meridian A B parallel 
 to NS. The bearing of the 
 first course is N 10° 15' E. 
 From the meridian passing 
 through A lay off this bearing 
 angle with a protractor, as 
 directed in Art. 1352. The 
 first course is 375 ft. Draw a 
 line through A having the 
 given bearing, and scale the 
 distance 375 ft. This will bring 
 us to Sta. 3 + 75, which we de- 
 note by the letter C, where a 
 bearing of N 60° E is taken. 
 The end of this course is at 
 Sta. 6 + 90. The length of the 
 second course will, therefore, be the difference between 
 6 + 90 and 3 + 75, which is 315 feet. Through C draw a 
 meridian C D, from which lay off the bearing angle of 60° 
 and draw a line marking the second course. Scaling the 
 distance 315 feet we reach Sta. 6 + 90, which we call E. 
 Here a bearing N 83° 30' E is taken. Through E draw a 
 meridian E E, and from it lay off the bearing N 83° 30' E. 
 The end of this course is at Sta. 10 + 40. Its length will, 
 therefore, be the difference between 10 + 40 and 6 + 90, 
 which is 350 ft. 
 
 Scale off this distance from E, locating Sta. 10 + 40, 
 which we call G. The bearing at 6^ is S 81° 20' E. 
 Through G draw the meridian G H. As the bearing is 
 S E, the meridian will fall below the station, from which 
 lay off the bearing S 81° 20' E, and draw a line in the 
 direction of this course. The next bearing is taken at 
 
 NOTES FOR LINE a. 
 
 Stations. 
 
 Bearings. 
 
 28 + 15 
 
 End of line. 
 
 23 + 55 
 
 S 45° 00' E 
 
 18 + 92 
 
 S 70° 45' E 
 
 14 + 20 
 
 N 80° 30' E 
 
 10 + 40 
 
 S81° 20' E 
 
 6 + 90 
 
 N 83° 30' E 
 
 3 + 75 
 
 N 60° 00' E 
 
 
 
 N10° 15' E 
 
750 
 
 MAPPING. 
 
 Sta. 14 4- 20. The length of the course is, therefore, the 
 difference between 14 + 20 and 10 -f- 40, which is 380 ft. 
 Call Sta. 14 +20, K. Through A' draw the meridian K L. 
 The bearing here is N 80° 30' E. From the meridian K L, 
 lay off this bearing and draw a line in the direction of the 
 course. In a similar manner locate the remaining stations 
 and lay off the remaining bearings of the line. The bearing 
 of each course should be distinctly written above it, the 
 letters reading in the same direction in which the line is 
 measured. 
 
 The notes for the lines b and c are as follows: 
 
 NOTES FOR LINE b. 
 
 Stations. 
 
 Bearings. 
 
 Distances. 
 
 1 
 2 
 3 
 4 
 5 
 
 N 40^° E 
 N 65i° E 
 S 75i° E 
 S 45i° E 
 S 20i° W 
 
 4.22 chains 
 6.75 chains 
 8.70 chains 
 6.60 chains 
 5.18 chains 
 
 NOTES FOR LINE c 
 
 Stations. 
 
 Bearings. 
 
 Distances. 
 
 1 
 2 
 3 
 4 
 5 
 
 S 47° E 
 N 20^° E 
 S 80° E 
 S 20° E 
 N 65i° E 
 
 6.60 chains 
 8.80 chains 
 4.32 chains 
 6.54 chains 
 7.48 chains 
 
 1354. The regular 100-foot stationing is used in rail- 
 road and highway surveying, but in land surveying the 
 lengths of the courses are given in surveyors' chains. As 
 the fractional parts of chains are given decimally, the 
 
MAPPING. 751 
 
 length of each course is readily scaled on the plat with a 
 decimal scale. The notes of line b are platted as follows: 
 The starting point is called Sta. 1, and so marked on the 
 plat. Call Sta. 1, A. Through A draw a meridian A B, 
 and from it lay off the first bearing, N 40^° E. The first 
 course is 4.32 chains in length, which lay off. to a scale of 
 2 chains to the inch, locating Sta. 2, which call C. Through 
 C draw a meridian C D, and lay off the given bearing 
 N 65^° E. The course with this bearing is 6.75 chains in 
 length, which scale off, locating Sta. 3. In similar manner 
 plat the remainder of line b, and also line c. Mark dis- 
 tinctly each course, giving its direction and length, being 
 careful that the figures and letters shall read in the same 
 direction in which the line is being run. 
 
 1355. To Lay Off an Angle by its Tangent.— In 
 
 laying off an angle by its tangent, the line from which the 
 angle is turned is prolonged to a distance equal to the 
 length of the assumed radius. The length of the tangent 
 of the given angle is then found in terms of the assumed 
 radius and the tangent platted. A line joining the angular 
 point with the extremity of the calculated tangent will give 
 the direction of the required line, which is then measured to 
 the given scale. 
 
 Let A B, in Fig. 330, be the given line, from which an 
 angle of 30° 15' is to be laid off to the right at the point B. 
 
 Produce A B to (7, ma- b B^4 00' 
 
 king BC= 400 feet, the 
 
 length of the assumed 
 
 radius. The tangent 
 
 of 30° 15' in terms of a 
 
 radius 1, is. 58318, which, ^'^- ^• 
 
 multiplied by 400 feet, the length of the assumed radius, 
 
 gives 233.27 feet, the length of the required tangent. At 
 
 C erect a perpendicular to B C 233.27 feet in length, equal 
 
 to the calculated tangent. Denote the end of this tangent 
 
 by C. Join B and C. The angle C B C = m° 15', the 
 
 given angle, and the line B C is the required line. 
 
752 
 
 MAPPING. 
 
 The following notes which are platted in Plate, Title: 
 Platting Angles II, Fig. 2, the student will plat to a scale 
 of 200 feet to the inch : 
 
 NOTES FOR LINE a. 
 
 Stations. 
 
 Angles. 
 
 Bearings. 
 
 25 + 00 
 
 19 + 97 
 
 13 + 22 
 
 5 + 00 
 
 
 
 End of Line 
 L. 40° 10' 
 R. 32° 15' 
 R. 43° 30' 
 
 N 78° 45' E 
 S61°05'E 
 N 86° 40' E 
 N 43° 10' E 
 
 The notes for line a are platted as follows: Having ad- 
 justed the paper to the drawing board and drawn a merid- 
 ian iV 5, fix the starting point A, which number 0. The 
 first course is 500 feet in length, which plat by drawing a 
 meridian A B through Sta. 0, and scale oflE 400 ft. equal to 
 the length of the assumed radius A C. The bearing of 
 the first course is N 43° 10' E. The tangent of 43° 10' 
 is .93797, which, multiplied by 400, the length of the radius, 
 gives 375.19, the length of the required tangent. Erect a 
 perpendicular \.o A B txX. C, and on this perpendicular scale 
 off to the right, the tangent 375.19 ft., calling the extremity 
 of the tangent D. Draw A D. The angle CAD will 
 be 43° 10'. The first course is 500 feet in length, which 
 scale off on the line A D 2it 200 ft. to the inch, locating Sta. 
 5 + 00 at E. The angle at Sta. 5 + 00 is 43° 30' to the right. 
 Produce A E and scale off the radius E 7^=400 ft. The 
 tangent of 43° 30' = .94896, which, multiplied by 400, gives 
 379.58 ft., the length of the required tangent. Erect a per- 
 pendicular to E F at F, and scale off, to the right, the tan- 
 gent 379.58 ft., locating the point G. Draw E G. The 
 angle F E G '\s 43° 30', and the line E G the required line, 
 the bearing of which is N 80° 40' E. Produce E G to H, 
 making /: //= 1,322 - 500 = 822 ft. in length. 
 
MAPPING. 
 
 753 
 
 The line changes direction again at Sta. 13 -f 22, where 
 an angle of 32° 15' is turned to the right. Denote Sta. 
 13 + 22 by H. Produce E H 400 feet, equal to the assumed 
 radius, calling its extremity K. The tangent of 32° 15' = 
 .63095, which, multiplied by 400 feet, gives 252.38 feet, the 
 length of the required tangent. Erect a perpendicular to 
 H K 2X K and on that perpendicular scale off, to the right, 
 the tangent 252.38 feet, locating the point L. Join H 
 and L. The angle K H L \s 32° 15' and the bearing oi H L 
 is S 61° 05' E. 
 
 The line changes direction again at Sta. 19 + 97. Call 
 this station AT. The angle at this point is 40° 10' to the left. 
 Produce H M 400' to yV, and at N erect a perpendicular 
 to M N. The tangent of 40° 10' is .84407, which, multiplied 
 by 400, gives 337.63 feet, the length of the required tangent. 
 On the perpendicular to AT N sc2i\& off, to the left, this tan- 
 gent, locating the point O. Join>/and O. The end of the 
 line is Sta. 25 + 00. The length of the last course is readily 
 found by subtracting 19 + 97 from 25 + 00. The difference, 
 503 feet, is scaled off on M O, locating the point P, the end 
 of the line. The bearing of M Pis N 78° 45' E. In a 
 similar manner plat the notes of line b. 
 
 NOTES FOR LINE b. 
 
 Stations. 
 
 Angles. 
 
 Bearings. 
 
 27 + 47 
 
 End of Line 
 
 
 
 
 20 + 97 
 
 R. 
 
 42° 
 
 20' 
 
 S34° 
 
 25' 
 
 E 
 
 13 + 73 
 
 R. 
 
 49° 
 
 10' 
 
 S76° 
 
 45' 
 
 E 
 
 7 + 63 
 
 L. 
 
 62° 
 
 15' 
 
 N54° 
 
 05' 
 
 E 
 
 0. 
 
 
 
 
 S 63° 
 
 40' 
 
 E 
 
 1356. To Lay Off an Angle by Latitude and 
 Departure. — The subject of latitudes and departures was 
 discussed in the section on Land Surveying, and the theory 
 needs no explanation in connection with this subject. 
 
754 
 
 MAPPING. 
 
 Suppose the bearing of a line is N 40° E, and its length is 300 
 feet. Its latitude and departure are calculated as follows: 
 
 Distances. 
 
 Latitudes. 
 
 Departures. 
 
 3 ft. 
 
 22 9 8 
 
 19 2 8 
 
 ft. 
 
 0000 
 
 0000 
 
 Oft. 
 
 0000 
 
 0000 
 
 3 ft. 
 
 + 22 9.8 ft. 
 
 + 192.8 ft. 
 
 Departure 192.8' 
 
 The student should bear in mind that north latitudes and 
 east departures are +, and south 
 latitudes and west departures are — . 
 ^^ Let A, in Fig. 331, be the station 
 at which the bearing is taken. 
 Through A draw the meridian A^ S. 
 From A upwards scale the calculated 
 latitude 229.8 ft., marking the ex- 
 tremity B. At B erect a perpen- 
 dicular to the meridian N S, draw- 
 ing it from left to right, as the 
 bearing is east. On this perpen- 
 dicular scale off the calculated de- 
 parture 192.8 ft., locating the point 
 C. Join A and C. The angle BAC 
 
 is 40°, equal to the given bearing, and A C is equal to the 
 
 length of the given course, viz., 300 ft. 
 
 Example. — Calculate the latitudes and departures of the following 
 courses, and plat them by means of total latitudes and total departures 
 from Sta. 1. 
 
 Fig. 331. 
 
 
 Bearings. 
 
 Distances. 
 
 Latitudes. 
 
 Departures. 
 
 Stations. 
 
 N + 
 
 S - 
 
 E + 
 
 W - 
 
 1 
 2 
 3 
 4 
 
 N 10i° E 
 N 41i" E 
 N 84i' E 
 S 25^" E 
 
 250 ft. 
 123 ft. 
 215 ft. 
 210 ft. 
 
 246 ft. 
 91.76 ft. 
 20.64 ft. 
 
 189.94 ft. 
 
 44.5 ft. 
 
 81.92 ft. 
 
 214.03 ft. 
 
 89.57 ft. 
 
 
MAPPING. 
 
 755 
 
 Solution. — 
 
 Distances. 
 250 ft. 
 
 200^ ft. 
 
 50 ft. 
 
 Oft. 
 
 Latitndes. 
 
 1968 
 4920 
 0000 
 
 Departures. 
 
 0356 
 0890 
 0000 
 
 250 ft. 
 
 246.000 ft. 
 
 44.500 ft. 
 
 123 ft. 
 
 
 
 100 ft. 
 
 2 ft. 
 
 3 ft. 
 
 0746 
 1492 
 2238 
 
 0666 
 1332 
 1998 
 
 1 2 3 ft. 
 
 91.758 ft. 
 
 81.918 ft. 
 
 215 ft. 
 
 
 
 200 ft. 
 
 10 ft. 
 
 5 ft. 
 
 0192 
 0096 
 0479 
 
 1991 
 0995 
 
 4977 
 
 215 ft. 
 
 2 0.63 9 ft. 
 
 214.027 ft. 
 
 2 1 ft. 
 
 
 
 200 ft. 
 
 10 ft. 
 Oft. 
 
 1809 
 0904 
 0000 
 
 0853 
 0427 
 0000 
 
 2 1 ft. 
 
 189.940 ft. 
 
 8 9.5 70 ft. 
 
 Stations. 
 
 Total Latitudes from 
 Station 1. 
 
 Total Departures from 
 Station 1. 
 
 1 
 2 
 8 
 4 
 5 
 
 0.00 ft. 
 + 246.00 ft. 
 + 337.76 ft. 
 + 358.40 ft. 
 + 168.46 ft. 
 
 0.00 ft. 
 + 44.50 ft. 
 + 126.42 ft. 
 + 340.45 ft. 
 + 430.02 ft. 
 
 The platting of the courses is as follows: On the merid- 
 ian A'^ 6\ Fig. 332, take a point which call Sta. 1. The total 
 latitude of Sta. 2 is + 246 feet, and, as it is a plus latitude, 
 it must be scaled off on the meridian above Sta. 1, locating 
 
756 
 
 MAPPING. 
 
 the points. The total departure of Sta, 2 is +44.5 feet. 
 This departure will therefore be to the right of the merid- 
 ian N S. At A, erect a perpendicular to the meridian, and 
 upon it scale off the total latitude 44.5 feet, locating Sta. 2. 
 The line joining Stas. 1 and 2, i. e., the first course, will 
 have a bearing of N 10^° E. Its length, viz., 250 feet, we 
 write on the plat, the figures reading in the same direction 
 in which the line is being run. 
 
 N 
 
 k 
 
 Total Lat+368.4(f^ 
 TotalLat+33r.76t 
 
 Total Lai.+246' 
 
 TotalLat.+J68.46! 
 
 Total Dejk +340.45' 
 ^ Total Dep^ 
 B +126.42^ /3 
 
 Total ^/V 
 Dep. 
 
 +■ 
 
 Fig. 332. 
 
 The total latitude of Sta. 3 is +337.76 feet, which we scale 
 off on the meridian above Sta. 1, locating the point B, and 
 on a perpendicular to the meridian at B, we scale off the total 
 departure of Sta. 3, which is + 120.42 feet, locating Sta. 3. 
 The line joining Stas. 2 and 3 has a bearing of N 41f° E, 
 and length of 123 feet. The total latitude of Sta. 4 is 
 + 358.4 feet, which we scale off on the meridian above Sta. 1, 
 locating the point C, where we erect a perpendicular to the 
 meridian and upon it scale off the total departure of Sta. 4, 
 
MAPPING. 757 
 
 viz., + 340.45 feet, locating Sta. 4. The line joining Stas. 3 
 and 4 will have a bearing of N 84^° E, and a length of 215 feet. 
 The total latitude of Sta. 5 is + 1G8.46 feet, which we scale 
 off on the meridian locating the point Z>, where we erect a 
 perpendicular to the meridian and upon it scale off the total 
 departure of Sta. 5, viz., -j- 430. 02 ft., locating that point. 
 The line joining Stas. 4 and 5 has a bearing of S 25^° E, 
 and a length of 210 ft. This method of platting bearings or 
 angles is more accurate than either of the foregoing methods, 
 as each course is platted independently. Great care must, 
 however, be observed in making the additions by which total 
 latitudes and departures are obtained. Tables of latitudes 
 and departures are commonly calculated to quarter degrees. 
 See table of Latitudes and Departures. Where angles are 
 read to single minutes, a table of sines and cosines may be 
 used to advantage. The two following formulas should be 
 memorized : 
 
 Latitude = distance X cos bearing. (9^») 
 Departure = distance X sin bearing. (98.) 
 
 1357. In preliminary railroad work, angles are com- 
 monly platted by tangents, but on difficult parts of the line 
 where all dependence must be placed on a paper location, 
 latitudes and departures should be used and the line platted 
 to a scale that will admit of full topographical details. 
 
 For practice in platting lines by latitudes and departures, 
 the following examples are given. The notes of Example 1 
 are platted in Fig. 333, and those of Example 2 are platted 
 in Fig. 334. 
 
 The student should carefully study the different steps 
 given under Art. 1356, and illustrated in Fig. 332, before 
 undertaking to plat the following notes. He should cal- 
 culate the latitudes and departures for each course, compa- 
 ring his results with those given in the text and likewise with 
 the total latitudes and departures for platting. These plats 
 he will submit for inspection, together with Plate, Title: 
 Platting Angles II. 
 
758 
 
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MAPPING. 
 
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760 
 
 MAPPING. 
 
 A piece of drawing paper one-half the size of an ordinary 
 drawing plate will be large enough to contain plats of both 
 lines. The total latitudes and departures in both examples 
 are reckoned from Station 1, which in Fig. 333 is the most 
 westerly station, and in Fig. 334 the most easterly one. 
 Plat the courses of Example 1 to a scale of 2 chains to the 
 inch, and those of Example 2 to a scale of 200 feet to the 
 inch. 
 
 N.89tK 
 
 Fig. 888. 
 
 In Fig. 333, a magnetic meridian is drawn through Sta. 1, 
 which we call A. We find in the column for total latitudes 
 and departures from Sta. 1 (see Example 1), that the total 
 latitude of Sta. 2 is+ 375.9 links, which we scale off on the 
 meridian above ^ to a scale of 2 chains or 200 links to the 
 inch, locating the point B. The total departure of Sta. 2 is 
 + 214.9 links, which we scale off at 2 chains to the inch on a 
 
MAPPING. 
 
 761 
 
 perpendicular to the meridian at B, locating Sta. 2, which we 
 call C. A line joining A and 6" will have the given length 
 and bearing of the first course, viz., length 4.33 chains, and 
 bearing N 29|° E. 
 
 The total latitude of Sta. 3 is -f- 461.2 links, which we scale 
 upon the meridian above A at 2 chains or 200 links to the 
 inch, locating the point D. The total departure of Sta. 3 is 
 -\- 724.8 links, which we scale off on a perpendicular to the 
 
 SSf. 
 
 Fig. 334. 
 
 meridian at D, locating Sta. 3, which we call E. A line 
 -joining C and E will have the given length and bearing of 
 the second course, viz., length 5.17 chains, and bearing 
 N 80^° E. In a similar manner plat the remaining courses, 
 bearing in mind that positive latitudes are measured on the 
 meridian above Sta. 1, and positive departures on perpen- 
 diculars to the right of the meridian, while negative latitudes 
 
762 MAPPING. 
 
 are measured on the meridian below Sta. 1, and negative 
 departures, if there were any, on perpendiculars to the left 
 of the meridian. The notes for Example 2 are similarly 
 platted, excepting that the meridian passes through the 
 most easterly station, as all the departures from Sta. 1 are 
 negative. The lengths of the courses in this example are 
 given in feet, and are to be platted to a scale of 200 feet to 
 the inch. Write the bearing of each line distinctly, being 
 careful that the letters read in the same direction in which 
 the line is run. The student is expected to accompany each 
 drawing with a brief description of the successive steps 
 taken in the work. 
 
 1358. Parallel Rulers. — A parallel rule is a straight 
 edge carried on milled rollers of equal diameter, having a 
 common axis. They are of great service in drawing meridian 
 lines. A magnetic meridian is drawn the entire width of 
 the sheet which is to contain the plat. The straight edge 
 of the rule is then made to coincide with the meridian line 
 and then rolled across the paper until the straight edge 
 passes through the point where the angle is to be measured. 
 A line is then drawn following the straight edge ; this will 
 be a meridian line. 
 
 1359. The Line of Survey. — The line of prelim- 
 inary survey is a succession of straight lines and angles, 
 or an angle line, as it is commonly called, while the 
 located line is a succession of straight lines and curves. 
 
 1360. Tangents and Curves. — Though this subject 
 has been considered in the section on Surveying, yet some 
 additional matter may be of advantage in connection with 
 the subject of mapping. 
 
 1361. Map of Final Location. — In mapping a final 
 location the measurements should be made from inter- 
 section point to intersection pomt, and the angles platted 
 either by tangents or by latitudes and departures. The 
 points of curve are then located by scaling the tangent 
 distances from the intersection points. The curve centers 
 
MAPPING. 
 
 763 
 
 o 
 
 v^* 
 
 
 
 FIG. 3.35. 
 
764 
 
 MAPPING. 
 
 are best determined by describing intersecting arcs from 
 the tangent points as centers, with radii equal to that of the 
 given curve. 
 
 Let it be required to plat by tangents the following 
 location notes: 
 
 Stations. 
 
 Degree of 
 Curve. 
 
 Intersection 
 Angle. 
 
 Tangent. 
 
 Magnetic 
 Bearing. 
 
 25+50 
 20+ 10 
 14+ 55 
 10 + 80 
 
 
 P. T. 
 
 P. C. 5° L. 
 
 P. T. 
 
 P. C. 6° R. 
 
 
 
 N 1° 00' E 
 
 27° 00' 
 
 275.20 ft. 
 
 
 
 N 28° 00' E 
 
 22° 30' 
 
 190.03 ft. 
 
 
 N 5° 30' E 
 
 
 
 
 
 
 The tangent distances are found by the formula 
 
 r= Tetany/. 
 
 (See Art. 1251.) The first curve is 6° R. ; the intersec- 
 tion angle / is 22° 30'. The radius of a 6° curve is 955.37 
 feet. See table of Radii and Chord and Tangent Deflec- 
 tions. 
 
 i 7=11° 15'. Tan 11° 15' = .19891; then 955.37 X 
 .19891 ft. = 190.03 ft. = T; which we place in the column 
 headed "tangent," opposite the intersection angle 22° 30'. 
 The second curve is 5° L; the intersection angle is 27° 00'. 
 The radius of a 5° curve is 1,146.28 feet. ^ 7=13° 30'. 
 Tan 13° 30' = .24008, and 1,146.28 ft. X .24008 = 275.2 ft. = 
 T, which we place in tangent column opposite the 
 intersection angle 27° 00'. 
 
 A plat of these notes is given in Fig. 335. The order of 
 work is the following: First we select a starting point A, 
 which we number 0, and through this point draw a meridian 
 A B with its north point at the top of the plat. 
 
 The first course has a bearing N 5° 30' E. From Sta- 
 tion 0, scale off on the meridian 600 feet, the length of our 
 radius for platting angles. The bearmg angle is 5° 30' and 
 
MAPPING. 765 
 
 its tangent .09629, which, multiplied by 600, the radius, 
 gives 57.77 feet, the length of the required tangent. Call 
 the extremity of the radius C. At C erect a perpendicular 
 to A B, and on it lay off the tangent 57.77 feet, locating the 
 point D. Join A and D. The angle C A D = 5° 30'. The 
 P. C. of the first curve is at Station 10+ 80. The tangent 
 distance, as given in the preceding table, is 190.03 feet. 
 Hence, the distance from the starting point to the first in- 
 tersection point is the sum of 1,080 and 190.03 feet, which 
 is 1,270.03 feet. Produce A D, making a total distance of 
 1,270.03 feet to the point of intersection £, and 600 feet 
 additional for the radius by which the next angle is platted. 
 Call the extremity of this radius F. The intersection angle 
 of the first curve is 22° 30'. Its tangent is .41421, which, 
 multiplied by 600, the given radius, gives 248.52 feet as the 
 required tangent for platting the angle. At F erect a per- 
 pendicular to the radius F F and scale off the tangent 
 FG= 248.52 feet, locating the point G. Join F and G. 
 The angle F F G is 22° 30', and the bearing of the tangent 
 F G is "N 28° E. Next, from the point of intersection F, 
 scale off on the lines F D and F G the tangent distance 
 190.03 feet, locating the P. C. at H, Station 10 + 80, and 
 the P. T. at K, Station 14 + 55. Now, from H and K as 
 centers with a radius 955.37 feet = radius of 6° curve, de- 
 scribe arcs intersecting at the point L. Then, from Z, as a 
 center with the same radius, describe a curve joining the 
 points H and K. The curve H K will be a 6° curve and 
 will be tangent to the lines H D and A' G" at the points of 
 curve H and K. The next intersection point M is in the line 
 E G produced. The distance between these intersection 
 points is made up of three parts, viz., the tangent of pre- 
 ceding curve, which we know to be 190.03 feet; the inter- 
 mediate tangent, i. e., the distance from the P. T. of the 
 first curve to the P. C. of the second curve, and the tangent 
 of the next curve following. The P. T. of the first curve is 
 at Station 14 + 55; the P. C. of the second curve is at 
 Station 20+10; the intermediate tangent is, therefore, the 
 difference between 14 + 55 and 20 + 10, which is 555 feet. 
 
766 MAPPING. 
 
 The tangent of the second curve is 275.2 feet. Hence, 
 the distance from the intersection point E of the first curve 
 to the intersection point M of the second curve is the sum 
 of 190.03, 555, and 275. 2 ft., which is 1,020.23 ft. Produce 
 E G so as to contain 1,020.23 ft., and 600 additional feet for 
 a radius, the extremity of which call N. The intersection 
 angle of the second course is 27° 00' L., tan 27° = .50953. 
 Radius 600ft. X .50953 = 305.72 ft., the length of the re- 
 quired tangent. Accordingly, at A'' we erect a perpendicular 
 to the radius M N^ and on that perpendicular, scale off the 
 tangent 305.72 feet, locating the point O. Join 3/ and O. 
 The angle N M O \% 27° 00', equal to the given intersection 
 angle, and the bearing of the tangent yl/ (9 is N 1° E. 
 From M on the lines M K and M O scale off the tangent 
 distance 275.20 feet, locating the P. C. at P, Sta. 20+10, 
 and the P. T. at (2, Sta. 25 + 50. Then, from P and Q as 
 centers with radii of 1,146.28 feet, the radius of a 5° curve, 
 describe arcs intersecting at R. From /? as a center with 
 the same radius describe the curve P Q, which is a 5° curve, 
 and is tangent to the lines Af K and M O 2it P and Q. 
 Write the bearing of each tangent in its proper place, being 
 careful that the bearings shall read in the same direction in 
 which the line is being run. 
 
 PLATE, TITLE: MAP OF RAILROAD LOCATION. 
 
 1362. This plate contains two maps of railroad loca- 
 tion. Figs. 1 and 2, the notes for which are given in the fol- 
 lowing pages. All the angles are laid off by tangents and 
 the notes of the alinement given in detail, all of which the 
 student must carefully go over and check. 
 
 The student, before commencing these drawings, should 
 first note that the magnetic meridian (by means of which 
 the direction of the first tangent of each line is determined) 
 is parallel to the right and left border lines of the plate. 
 He must also determine by measurement from the border 
 lines the location of the starting point of each line 
 
MAPPING. 767 
 
 Without these precautions, the lines are liable to run off the 
 paper, necessitating a repetition of the work, and involving 
 the erasure of lines, which always soils the paper and mars 
 the appearance of the drawing. 
 
 He will make the drawing to a scale of 300 feet to the 
 inch. If his scale reads only 200 feet to the inch, he will 
 reduce the distances given to a scale of 300 feet to the inch, 
 to their equivalent to a scale of 200 feet to the inch. The 
 process of reduction is simple and may be readily understood 
 from the following: A line which measures 300 feet in 
 length to a scale of 300 feet to the inch will measure but 
 200 feet to a scale of 200 feet to the inch. Hence, in chang- 
 ing a scale from 300 feet to 200 feet to the inch the distances 
 and dimensions will scale but f of the original distances and 
 dimensions. 
 
 Example. — A line measures 963 feet to a scale of 300 feet to the 
 inch. What will it measure to a scale of 200 feet to the inch ? 
 
 Solution. — | of 963 = 642, i.e., to a scale of 200 feet to the inch, the 
 line will measure 642 feet. 
 
 1 363. The order of platting the notes is as follows : First 
 draw a meridian as indicated by the arrow. Next, having 
 located the starting point A, Fig. 1, which is numbered 0, 
 draw through that station a parallel meridian A B. We find 
 from the notes that the direction of the back tangent A A' 
 (which we will consider a part of a line of railroad already con- 
 structed) is due north and south, and that Sta. is the P. C. 
 of an 8° R. curve with a central or intersection angle of 
 63° 10'. The tangent distance we find by the formula 
 T== R tan \ /, is 440.7 feet. This distance we scale off on 
 the meridian above the point ^ to a scale of 300 ft. to the 
 inch, locating the point C, which is the intersection point of 
 the back and forward tangents. 
 
 Next, from Con the same meridian, we scale off the radius 
 C D oi 400 feet for laying off the angle of the first curve. 
 The angle of this curve is 63° 10'. The tan of 63° 10' is 
 1.97681. The radius 400 ft. X 1.97681 =790.7 ft., the length 
 of the required tangent. At D erect a perpendicular to 
 
7G8 
 
 MAPPING. 
 NOTES FOR FIG 
 
 . 1. 
 
 
 Station. 
 
 Deflection. 
 
 Total 
 Angle. 
 
 Magnetic 
 Course. 
 
 Calculated 
 Course. 
 
 40 
 
 12° 00' 
 
 6° 00' 
 
 18° 00' 
 
 12° 00' 
 
 6° 00' 
 
 P. C. 12° L. 
 
 
 
 
 89 
 
 
 
 
 38 + 00 
 
 36° 00' 
 
 
 
 37 
 
 
 
 36 
 
 
 
 
 35 + 00 
 
 
 
 
 34 
 
 
 
 
 33 + 04.9 
 33 
 
 10° 40.3' P. T. 
 10° 30' 
 7° 00' 
 3° 30' 
 7° 14.7' 
 3° 44.7' 
 0° 14.7' 
 P. C. 7° R. 
 
 35° 50' 
 
 S 36° 30' E 
 
 S 36" 40' E 
 
 32 
 
 
 
 
 31 
 
 
 
 
 30 
 
 14° 29.4' 
 
 
 
 29 
 
 
 
 28 
 
 
 
 
 27 + 93 
 
 
 
 
 24 
 
 
 
 
 21 
 
 
 
 
 
 20 + 54.9 
 20 
 
 10° 38.8' P. T. 
 9° 00' 
 6° 00' 
 3° 00' 
 11° 31.2' 
 8° 31.2' 
 5° 31.2' 
 2° 31.2' 
 P. C. 6° R. 
 
 44° 20' 
 
 S 72° 30' E 
 
 S 72° 30' E 
 
 19 
 
 
 
 
 18 
 
 
 
 
 17 
 
 23° 02.4' 
 
 
 
 16 
 
 
 
 15 
 
 
 
 
 14 
 
 
 
 
 13+ 16 
 
 
 
 
 12 
 
 
 
 
 11 
 
 
 
 
 
 10 
 
 
 
 
 
 9 
 
 
 
 
 
 8 
 
 
 
 
 
 7 + 89.6 
 
 7 
 
 15° 35' P. T. 
 
 12° 00' 
 
 8° 00' 
 
 4° 00' 
 
 16° 00' 
 
 12° 00' 
 
 8° 00' 
 
 4° 00' 
 
 P. C. 8° R. 
 
 63° 10' 
 
 N 68° 00' E 
 
 N 63° 10' E 
 
 6 
 
 
 
 
 5 
 
 
 i 
 
 4 
 
 82° 00' 
 
 ! 
 
 3 
 
 j 
 
 2 
 
 
 1 
 
 1 
 
 
 
 
 
 
 
 North 
 
 North 
 
 
 
 
 
MAPPING. 
 NOTES FOR FIG. 1. 
 
 769 
 
 Remarks. 
 
 June 28, 1894. 
 
 Int. Ang. 
 
 = 72° 00' 
 
 From intersection to intersection. 
 
 12° curve, L. R. 
 
 = 478.34 ft. 
 
 Tan preceding curve = 264.8 ft. 
 
 T. 
 
 = 347.5 ft. 
 
 Tan between curves = 195.1 ft. 
 
 P. C. 
 
 Length curve 
 
 P. C. C. 
 
 Def. 100 ft. 
 
 Def. 1 ft. 
 
 = 35 + 00 
 = 600 ft. 
 = 41 + 00 
 = 6° 00' 
 = 3.6' 
 
 Tan 12° curve = 347.6 ft. 
 
 Total, = 807.5 ft. 
 tan 72° 00' = 3.07768 
 400 ft. X 3.07768 = 1,231.1 ft. 
 
 Int. Ang. 
 
 = 35° 50' 
 
 From intersection to intersection. 
 
 7° curve, R. R. 
 
 = 819.02 ft. 
 
 Tan preceding curve = 389.2 ft. 
 
 T. 
 
 = 264.8 ft. 
 
 Tan between curves = 738.1 ft. 
 
 P. C. 
 
 = 27 + 93 
 
 Tan 7° curve = 264.8 ft. 
 
 Length curve 
 P. T. 
 
 = 511.9 ft. 
 = 33 + 04.9 
 
 
 Total, =1,392.1 ft. 
 
 Def. 100 ft. 
 
 = 3° 30' 
 
 tan 35° 50' = .72211 
 
 Def. 1 ft. 
 
 = 2.1' 
 
 400 ft. X .72211 = 288.8 ft. 
 
 Int. Ang. 
 
 = 44° 20' 
 
 From intersection to intersection. 
 
 6° curve, R. R. 
 
 = 955.37 ft. 
 
 Tan preceding curve = 440. 7 ft. 
 
 T. 
 
 = 389.2 ft. 
 
 Tan between curves = 526.4 ft. 
 
 P.C. 
 
 = 13+16 
 = 738.9 ft. 
 
 Tan 6° curve = 389.2 ft. 
 
 Length of curve 
 
 Total, =1,356.3 ft. 
 
 P. T. 
 
 = 20 + 54.9 
 
 tan 44° 20' = .977 
 
 Def. 100 ft. 
 
 = 3° 00' 
 
 400 ft. X .977 = 390.8 ft. 
 
 Def. 1 ft. 
 
 = 1.8' 
 
 
 Int. Ang. 
 
 = 63° 10' 
 
 Radius 1 = 400 ft. 
 
 8° curve, R. R. 
 
 = 716.78 ft. 
 
 tan 63" 10' = 1.97681 
 
 T. 
 
 = 440.7 ft. 
 
 400 ft. X 1.97681 = 790.7 ft. 
 
 P.C. 
 
 = 
 
 
 Length of curve 
 
 = 789.6 ft. 
 
 
 P. T. 
 
 = 7 + 89.6 
 
 
 Def. 100 ft. 
 
 = 4° 00' 
 
 
 Def. 1 ft. 
 
 = 2.4' 
 
 
770 
 
 MAPPING. 
 NOTES FOR FIG. 2. 
 
 Station. 
 
 Deflection. 
 
 Total 
 Angle. 
 
 Magnetic 
 Course. 
 
 Calculated 
 Course. 
 
 13 + 41.7 
 13 
 
 10° 15' P. T. 
 9° 00' 
 6° 00' 
 3° 00' 
 6° 00' 
 3° 00' 
 P. C. 6° R. 
 
 32° 30' 
 
 S 79° 00' E 
 
 S 79° 00' E 
 
 13 
 
 
 
 
 11 
 
 
 
 
 10 + 00 
 
 12° 00' 
 
 
 
 9 
 
 
 
 8 + 00 
 
 
 
 
 5 
 
 
 
 
 3 
 
 
 
 
 
 
 
 
 
 S 46° 30' E 
 
 
 
 
 
 
 NOTES FOR FIG. \— Continued. 
 
 Station. 
 
 Deflection. 
 
 Total 
 Angle. 
 
 Magnetic 
 Course. 
 
 Calculated 
 Course. 
 
 69 + 10.1 
 
 61 + 65.1 
 
 61 
 
 15° 40' p. T. 
 
 12° 44.1' 
 
 8° 14.1' 
 
 3° 44.1' 
 
 P. C. 9° R. 
 
 End 
 31° 20' 
 
 of Line. 
 N 39° 45' E 
 
 N 39° 40' E 
 
 60 
 
 
 
 
 59 
 
 
 
 
 58 + 17 
 
 
 
 
 55 
 
 
 
 
 54 
 
 
 
 
 
 53 
 
 
 
 
 
 52 
 
 
 
 
 
 51 
 
 
 
 
 
 50 + 00 
 49 
 
 17° 30' P. T. 
 14° 00' 
 10° 80' 
 
 7° 00' . 
 
 3° 30' 
 14° 00' 
 10° 30' 
 
 7° 00' 
 
 3° 80' 
 18° 00' P. C. C. 7° L. 
 
 63° 00' 
 
 N 8° 15' E 
 
 N 8° 20' E 
 
 48 
 
 
 
 
 47 
 
 
 
 
 46 
 
 
 
 
 45 
 
 28° 00' 
 
 
 
 44 
 
 
 
 43 
 
 
 
 
 42 
 
 
 
 
 41 + 00 
 
 72° 00' 
 
 N 71" 15' E 
 
 N 71° 20' E 
 
MAPPING. 
 NOTES FOR FIG. 2. 
 
 771 
 
 Remarks. 
 
 June 28, 1894. 
 
 Int. Ang. = 32° 30' 
 6° curve. L. R. = 955.37 ft. 
 T. = 278.5 ft. 
 P. C. = 8 + 00 
 Length curve = 541.7 ft. 
 P. T. =13 + 41.7 
 Def. 100 ft. = 3° 00' 
 Def. 1 ft. = 1.8' 
 
 Radius 1 = 400.0 ft. 
 From Sta. to P. C. = 800.0 ft. 
 Tan 6" curve = 278.5 ft. 
 
 Total from P. C. to P.I. = 1,078.5 ft. 
 tan 32° 30' = .63707 
 400ft. X. 63707= 254.8ft. 
 
 NOTES FOR FIG. \— Continued. 
 
 Remarks. 
 
 June 28, 1894. 
 
 Int. Ang. = 31° 20' 
 curve, R. R. = 637.27 ft. 
 T. = 178.7 ft. 
 P. C. = 58 + 17 
 Length curve = 348.1 ft. 
 P. T. = 61 + 65.1 
 Def. 100 ft. = 4° 30' 
 Def. 1 ft. = 2.7' 
 
 Int. Ang. = 63° 00' 
 7° curve, L. R. = 819.02 ft. 
 T. = 501.9 ft. 
 P. C. C. = 41 + 00 
 Length curve = 900 ft. 
 P. T. = 50 + 00 
 
 From intersection to intersection. 
 Tan preceding curve = 501.9 ft. 
 Tan between curves = 817.0 ft. 
 Tan 9° curve = 178.7 ft. 
 
 Total, = 1,497.6 ft. 
 
 tan 31° 20' =.60881 
 400ft. X. 60881 = 243.5 ft. 
 
 From intersection to intersection. 
 Tan preceding curve = 347.6 ft. 
 Tan between curves = 0.0 ft. 
 Tan 7° curve = 501.9 ft. 
 
 Total, 
 
 = 849.5 ft. 
 tan 63° = 1.96261 
 400 ft. X 1.96261 = 785 ft. 
 
772 
 
 MAPPING. 
 
 NOTES FOR FIG. ^—Continued. 
 
 Station. 
 
 Deflection. 
 
 Total 
 Angle. 
 
 Magnetic 
 Course. 
 
 Calculated 
 Course. 
 
 57 + 40 
 47 + 19 
 
 47 
 
 8° 46.3' P. T. 
 
 8° 15' 
 
 5° 30' 
 
 2° 45' 
 
 8° 13.7' 
 
 5° 28.7' 
 
 2° 43.7' 
 14°01.7'P.C.C. 5°30'L. 
 14° 00' 
 10° 30' 
 
 7°00' 
 
 3° 30' 
 11° 58.2' 
 
 8° 28.2' 
 
 4° 58.2' 
 
 1° 28.2' 
 P. C. 7° L. 
 
 End 
 34° 00' 
 
 of Line. 
 N ir 15' E 
 
 N 11° 20' E 
 
 46 
 
 
 
 
 45 
 
 
 
 
 44 + 00 
 
 16° 27.4' 
 
 
 
 43 
 
 
 
 42 
 
 
 
 
 41 + 00.8 
 41 
 
 52° 00' 
 
 N 45° 15' E 
 
 N 45° 20' E 
 
 40 
 
 
 
 
 • 39 
 
 
 
 
 38 
 
 
 
 
 37 + 00 
 
 23° 56.4' 
 
 
 
 36 
 
 
 
 35 
 
 
 
 
 84 
 
 
 
 
 33 + 58 
 
 
 
 
 32 
 
 
 
 
 30 + 36.6 
 30 
 
 13° 27.8' P. T. 
 12° 00' 
 8° 00' 
 4° 00' 
 10° 37.2' 
 6° 37.2' 
 2° 37.2' 
 P. C. 8° L. 
 
 48° 10' 
 
 S 82° 80' E 
 
 S 82° 40' E 
 
 29 
 
 
 
 
 28 
 
 
 
 
 27 + 00 
 
 21° 14.4' 
 
 
 
 26 
 
 
 
 25 
 
 
 
 
 24 + 34.5 
 
 
 
 
 24 
 
 
 
 
 23 
 
 
 
 
 
 22 + 14.4 
 22 
 
 9° 39' P. T. 
 9° 00' 
 4° 30' 
 12° 36' 
 8° 06' 
 3° 36' 
 
 P. C. 9° L. 
 
 44° 80' 
 
 S 84° 20' E 
 
 S 84° 80 E 
 
 21 
 
 
 
 
 20 + 00 
 
 25° 12' 
 
 
 
 19 
 
 
 
 18 
 
 
 
 
 17 + 20 
 
 
 
 
 17 
 
 
 
 
 15 
 
 
 
 
 
 
 
 
 
 
MAPPING. 773 
 
 NOTES FOR FIG. 2— Continued. 
 
 Remarks. 
 
 June 28, 1894. 
 
 Int. Ang. = 34' 00' 
 5°30', L. R. = 1,042.14 ft. 
 T. =318.6 ft. 
 P. C. C. = 41 + 00.8 
 Length curve = 618.2 ft. 
 P. T. = 47 + 19 
 Def. 100 ft. = 2° 45' 
 Def. 1 ft. = 1.65' 
 
 Int. Ang. = 52° 00' 
 curve, L. R. = 819.02 ft. 
 T. = 399.5 ft. 
 P. C. = 33 + 58 
 Length curve = 742.8 ft. 
 P. C. C. = 41 + 00.8 
 Def. 100 ft. = 3° 30' 
 Def. 1 tt. = 2.1' 
 
 Int. Ang. 
 
 8° curve, L. R. 
 
 T. : 
 
 P. C. 
 
 Length curve 
 
 P. T. 
 
 Def. 100 ft. 
 
 Def. 1 ft. ; 
 
 Int. Ang. 
 
 9° curve, R. R. 
 
 T. 
 
 P. C. 
 
 Length curve 
 
 P. T. 
 
 Def. 100 ft. 
 
 Def. 1 ft. 
 
 : 48° 10' 
 
 : 716.78 ft. 
 
 : 320.4 ft. 
 24 + 34.5 
 602.1 ft. 
 
 : 30 + 36.6 
 
 : 4° 00' 
 2.4' 
 
 44° 30' 
 637.27 ft. 
 260.7 ft. 
 17 + 20 
 494.4 ft. 
 22 + 14.4 
 4° 30' 
 3.7' 
 
 From intersection to intersection. 
 Tan preceding curve = 399.5 ft. 
 Tah between curves = 0.0 ft. 
 Tan 5° 30' curve = 318.6 ft. 
 
 Total, = 718.Tft. 
 
 tan 34° 00' = .67451 
 400 ft. X .67451 = 269.8 ft. 
 
 From intersection to intersection. 
 Tan preceding curve = 320.4 ft. 
 Tan between curves = 321.4 ft. 
 Tan 7° curve = 399.5 ft. 
 
 Total, 
 
 = 1,041.3 ft. 
 tan 52° 00' = 1.27994 
 400 ft. X 1.27994 = 512 ft. 
 
 From intersection to intersection. 
 Tan preceding curve = 260.7 ft. 
 Tan between curves = 220. 1 ft. 
 Tan 8° curve = 320.4 ft. 
 
 Total, 
 
 = 801.2 ft. 
 tan 48° 10' = 1.11713 
 400 ft. X 1.11713 = 446.8 ft. 
 
 From intersection to intersection. 
 Tan preceding curve = 278.5 ft. 
 Tan between curves = 378.3 ft. 
 Tan 9° curve =260. 7 ft. 
 
 Total, 
 
 = 917.5 ft. 
 tan 44° 30' = .98270 
 400ft. X. 98270 = 393.1 ft. 
 
774 MAPPING. 
 
 A B, towards the right, as the curve is to the right, and 
 upon this perpendicular scale oflf the calculated tangent 
 700.7 ft., locating the point E. A line joining the points 
 C and ^ will give the direction of the forward tangent. On 
 the line C E, scale off from C the tangent distance, 440.7 ft., 
 locating the point /', which is the P. T. of the first curve. 
 From A and /"as centers, with radii of 716.78 ft., the radius 
 of an 8° curve, describe arcs intersecting at G. Then, from 
 G as a center, with the same radius, describe a curve joining 
 the points A and F. The curve A F\s zn 8° curve and tan- 
 gent to the lines A A' and F £ a.t the points A and F. 
 
 We find from the notes that the next curve is 6° R. Its 
 P. C. is at Sta. 13 + 16, and its central angle is 44° 20'. We 
 find its tangent distance is 389.2 ft. We next calculate the 
 distance from the intersection point of the first curve to the 
 intersection point of the second curve. The distance is com- 
 posed of three parts; viz., the tangent of the preceding 
 curve, which is 440.7 ft. ; the intermediate tangent, i. e., 
 from the P. T. of the preceding curve at Sta. 7 + 89.6 to the 
 P. C. of the second or 6° curve at Sta. 13 + 16, a distance of 
 526.4 ft., and the tangent of the 6° curve, which is 389.2 ft., 
 making a total distance of 1,356.3 ft. Produce the line CE, 
 and scale off from Con that line a total distance of 1,356.3 ft., 
 locating the point H, which is the intersection point of the 
 second or 6° curve. Produce C H 400 ft. to A" for a radius 
 in laying off the central angle, 44° 20' R., of the second 
 curve. The tangent of 44° 20' is .977, which, multiplied by 
 400, gives 390.8 ft. At A" erect a perpendicular to H K, and 
 upon it scale off the tangent 390.8 ft., locating the point L. 
 The line joining //and L gives the direction of the forward 
 tangent of the second curve. Next, from the intersection 
 point H, scale off on both back and forward tangents the 
 tangent distance 389.2 ft., locating the P. C. of the second 
 curve at J/, Sta. 13 + 16, and its P. T. at N, Sta. 20 + 54.9. 
 Next, from J/ and A^as centers, with a radius of 955.37 ft., 
 the radius of a 6° curve, describe arcs intersecting at O. 
 Then, from (9 as a center, with the same radius, describe a 
 curve joining the points M and A^. The curve M N is a 6° 
 
MAPPING. 775 
 
 curve and tangent to the lines F H and H L zX the points of 
 curve M and N. 
 
 The student will draw the tangent distances and the radii 
 and tangents for laying off angles in dotted lines, as they 
 are simply construction lines. The line of survey he will 
 draw in a full, bold line, as shown in the plate. The inter- 
 section points and the points of curve and tangent are 
 marked by small circles, the latter being more fully described 
 by their station numbers. Dotted radial lines are drawn 
 from the center of each curve to its P. C. and P. T. On 
 one of these radial lines the length of the radius of the curve 
 is written, and the amount of the central angle written with- 
 in the radial lines. The student will need no further direc- 
 tions to enable him to plat the balance of the line and also 
 the notes for Example 2, a plat of which is given in Fig. 2. 
 
 1364. Office Curves and Beam Compass. — Office 
 curves are curves of different radii, whose principal object 
 
 10 
 Scale 100 ft=' 1 in 
 12' 
 
 Pig. 836. 
 
 is to enable the engineer to readily select a curve which 
 shall best fit the ground lying between tangents, as shown 
 in the topographical map. They are commonly made of 
 pasteboard, each piece containing arcs of two different radii, 
 the degrees of curvature of which, together with the scale of 
 each, being distinctly written, as shown in Fig. 336. A 10° 
 curve to a scale of 100 feet to the inch will serve for a 5° 
 curve to a scale of 200 feet to the inch, or a 2° 30' curve to 
 a scale of 400 feet to the inch. In the same way, a 12° 
 curve to a scale of 100 feet to the inch will serve for a 6° 
 curve to a scale of 200 feet to the inch, or a 3° curve to a 
 
776 MAPPING. 
 
 scale of 400 feet to the inch. Office curves are applied 
 directly to the contour map upon which a grade line has 
 been platted, and the curves fitted to ground and tangent. 
 Compound curves are as readily fitted as simple curves. A 
 satisfactory line being decided upon, the tangent distances 
 are calculated and the curves struck with a compass. 
 
 When the radius is of considerable length, it is difficult to 
 describe a true circle with the ordinary compass and length- 
 ening bar. 
 
 An accurate substitute is found in the beam compass, 
 which consists of two upright legs; one pointed and fixed 
 at the center of the circle; the other leg carrying either 
 pencil or pen, with which the circle is described. Both legs 
 
 B 
 
 o 
 
 
 o 
 
 p 
 
 Fig. ,337. 
 
 are clamped to a horizontal arm called a beam, which is 
 lengthened or shortened to suit the radius. A cut of a beam 
 compass is shown in Fig. 337. A B is the beam, to which is 
 clamped the needle point at C and the pen or pencil at D. 
 At ^ is a milled-headed screw, which gives slow movement 
 to the pen or pencil at D and adjusts it to the required 
 radius. 
 
 TOPOGRAPHICAL DRAWING. 
 1365. General Definition. — Topographical 
 drawing consists of the representation of the different 
 features of any portion of the earth's surface. The different 
 features will comprise all its inequalities of surface, such 
 as hills, hollows, streams, lakes, valleys, and plains; the 
 location of towns, highways, canals, and railroads. Detailed 
 topographical maps give individual dwellings, boundaries of 
 fields, their owners, the charactei of the vegetation, etc. 
 
MAPPING. 
 
 777 
 
 1366. Systems. — There are three principal systems of 
 representing topographical features, viz. : 
 
 1. By level contours or horizontal sections. 
 
 2. By lines of greatest slope perpendicular to contours. 
 
 3. By shades from vertical light. 
 
 1367. Ridge Lines and Valley Lines.— Ridge 
 lines are the lines which divide the water falling upon them 
 and from which it passes off on opposite sides. They are 
 the lines of least slope when looking along them from above 
 downwards, and the lines of greatest slope when looking 
 along them from below upwards. They can be readily 
 determined by the slope level. On these lines are found the 
 projecting or protruding bends of the contour lines. 
 
 Valley lines are the reverse of ridge lines. They are 
 indicated by the water courses which follow or occupy them. 
 They are the lines of greatest slope when looked at from 
 above and of least slope when looked at from below. On 
 these lines are found all the receding or reentering points 
 of the contour lines. 
 
 1368. Forms of Ground. — It will be found from a 
 general examination of any surface that ground exists under 
 one of the five following conditions, viz. : 
 
 1. Sloping down on all sides ^ i. e., a hill, as shown in Fig. 
 
 Fig. 338. 
 
 Fig. 839. 
 
 338, the direction in which water would flow being indicated 
 by the arrows. 
 
778 
 
 MAPPING. 
 
 2. Sloping up on all sides, i. e., a hollow, as shown in 
 Fig. 339. 
 
 3. Sloping dozvn on tJirce sides, i. e., shoulder or prom- 
 ontory; the end of a ridge or watershed line, as shown in 
 Fig. 340. 
 
 Fig. 340. 
 
 Pig. 841. 
 
 4. Sloping up on three sides and down on one side, i. e., a 
 valley, as shown in Fig. 341. 
 
 5. Sloping up on two sides and down on two sides, 
 
 alternately, called a saddle, and 
 shown in Fig. 342. 
 
 1369. Clear and Intelligi- 
 ble Maps. — No pains should be 
 spared in making maps clear and 
 intelligible. All water courses, 
 whether occupied or dry, should 
 be accurately sketched, and gaps 
 should be left in the contour lines 
 at suitable intervals, with the eleva- 
 tion of the contours written in them. Where time and cost 
 are not to be considered, the lower sides of the contours may 
 be hatched as though water were draining off them, and the 
 valleys and low places tinted with a light shade of India ink. 
 Sometimes the spaces between the contour lines are tinted 
 with India ink, increasing the tint as the depth increases. 
 
 Ground under water is commonly so represented. Begin- 
 ning at low water-line, the space to the depth of G feet is 
 covered with a dark shade of India ink ; from feet to 12 feet 
 
 Fig. 342. 
 
MAPPING. 779 
 
 with a lighter shade ; from 12 feet to 18 feet with still lighter, 
 and from 18 feet to 24 feet with lightest of all. Greater 
 depths are marked in fathoms. 
 
 1 370. Uses of Contours : 
 
 1. To locate roads. 
 
 2. To obtain vertical sections — profiles. 
 
 3. To calculate excavation and embankment. 
 
 In both railroad and highway location, the contour map 
 is used in platting a grade line to which the final location 
 should closely approximate. The paper location is then made, 
 conforming as closely as possible to the grade line in the 
 contour map, and from that location a final profile is platted. 
 
 When the contour map is to be used as a basis for the cal- 
 culation of excavation and embankment, a hill or hollow is 
 conceived to be divided into horizontal sections. The areas 
 of the upper and lower bases of any section are then calcu- 
 lated and their average is multiplied by the altitude of the 
 section, which gives the content of that section. 
 
 PLATE, TITLE : CONTOURS AND SLOPES. 
 1371. This plate contains three examples in topograph- 
 ical drawing. Each example affords practice in drawing 
 shore lines. Fig. 1 is an example under the first system in 
 which the topography is represented by level contours, and 
 affords the student excellent practice in contour mapping. 
 Figs. 2 and 3 are examples under the second system in which 
 topography is represented by lines of greatest slope or 
 hatchings. 
 
 First System — By Level Contours. — In Fig. 1 the 
 situation is a steep hillside bordering upon a lake. The en- 
 gineer before commencing the field work should examine the 
 ground thoroughly in order that he may intelligently choose 
 a method of work well suited to the situation. In the case 
 in hand, the surface of the water in the lake is adopted as 
 the datum plane. 
 
780 MAPPING. 
 
 It is a common and excellent practice to divide the area to 
 be contoured into squares, the dimensions of which will de- 
 pend upon the area to be treated and the degree of detail 
 required in the work. Large areas are usually divided- into 
 squares containing 100 ft. on a side. The division lines 
 serve as guides to those taking the levels. The intersections 
 of the division lines being 100 ft. apart, they render the loca- 
 tion of any intermediate point an easy task. These inter- 
 sections are called stations, and are usually numbered 
 consecutively or distinguished in some other way. In Fig. 
 1 the area is divided into squares 100 ft. on a side. Base 
 lines A X and A H are first established where distant and 
 well-defined targets may be set up and the lines carefully meas- 
 ured. The importance of an accurately measured base line, 
 and of a distant fixed target can not be overestimated. The 
 lines of division are determined by laying off lines at 90° to 
 these bases, and are supposed to be parallel, a difficult thing 
 to accomplish in rough country where short sights are fre- 
 quent, and impossible if the initial angle of each line is not 
 turned from the same backsight, and that a comparatively 
 distant one. The base lines being established, the lines of 
 division are carefully run. The vertical division lines, i. e., 
 those parallel to general direction of the lake shore, are des- 
 ignated by the letters of the alphabet, the first being de- 
 scribed as line A^ the next as line B^ the next as line C, and 
 so on. The horizontal division lines are numbered consec- 
 utively, commencing with the bottom line, which is num- 
 bered 0, the next parallel to it 1, the next 2, and so on. 
 The intersections of the division lines locate the succeeding 
 stations on each line. This greatly simplifies the keeping of 
 the notes, and enables the engineer to readily locate any 
 point and brieflly describe it. Thus, the starting point of 
 line A is called line A^ 0; the next intersection is called line 
 A, 1; the next line A^ 2, etc. The engineer determines the 
 form of notes best suited to the situation. He will find a 
 leveling rod 20 ft. in length of great assistance when work- 
 ing in a locality where changes in elevation are frequent 
 and abrupt. The form of notes best adapted to the work in 
 
MAPPING. 
 
 781 
 
 hand is the following, the notes being a record of the levels 
 which are taken at each intersection of the division lines: 
 
 LEVELS OF LINE A. 
 
 Station. 
 
 Rod Reading. 
 
 Height of 
 Instrument. 
 
 Elevation. 
 
 B. M. 
 
 + 8.80 
 
 56.05 
 
 47.25 
 
 
 
 7.20 
 
 
 48.80 
 
 1 
 
 13.70 
 
 
 42.30 
 
 T. P. 
 
 - 19.72 
 
 
 36.33 
 
 
 + 4.20 
 
 40.53 
 
 
 2 
 
 5.70 
 
 
 34.80 
 
 3 
 
 14.80 
 
 
 25.70 
 
 T. P. 
 
 - 18.63 
 
 
 21.90 
 
 
 + 3.53 
 
 25.43 
 
 
 4 
 
 7.10 
 
 
 18.30 
 
 5 
 
 9.30 
 
 
 16.10 
 
 T. P. 
 
 - 18.55 
 
 
 6.88 
 
 
 + 3.22 
 
 10.10 
 
 
 6 
 
 9.60 
 
 
 0.50 
 
 6 + 05 
 
 
 
 Edge of Lake. 
 
 1372. The contour map is made as follows: First 
 we draw the outlines of the given area, 1,100 ft. in length 
 by 750 ft. in width, to a scale of 100 ft. to the inch. These 
 boundaries are then divided into equal spaces of 100 ft. each, 
 as shown in the engraving, and the lines of division drawn, 
 the boundaries being drawn full and the division lines dotted. 
 The vertical division lines, as before stated, are designated 
 by the letters of the alphabet, and the horizontal lines by 
 numerals. 
 
 From the level notes we find the elevations of the stations 
 on lines A and B. These elevations we mark on the map at 
 their proper stations, and then locate the contour lines as 
 follows: Beginning with line A, we find that the elevation 
 of Station is 48.8 ft. ; that of Station 1 is 42.3 ft. ; hence, 
 
782 
 
 MAPPING. 
 
 the difference of elevation between these stations is 48.8 — 
 42.3 = 6.5 ft. The distance between these stations is 100 ft., 
 
 and the rate of fall between Stations and 1 is equal to —— = 
 
 0.5 
 
 15.4, which is called a descending slope of 1 to 15.4. The 
 contours are 5 ft. apart, and, therefore, the elevations of 
 each contour will be some multiple of 5 ft. Contour 45 ft. 
 will come between Stations and 1 of line A. As the eleva- 
 tion of Station is 48.8 ft., we must, to reach contour 45, go 
 
 LEVELS OF LINE B. 
 
 Station. 
 
 Rod Reading. 
 
 Height of 
 Instrument. 
 
 Elevation. 
 
 
 
 10.10 
 
 
 7 + 12 
 
 
 
 Edge of Lake. 
 
 7 
 
 8.00 
 
 
 2.10 
 
 T. P. 
 
 - 1.24 
 
 
 8.86 
 
 
 + 19.84 
 
 28.70 
 
 
 6 
 
 8.30 
 
 
 . 20.40 
 
 T. P. 
 
 - 1.65 
 
 
 27.05 
 
 
 + 19.91 
 
 46.96 
 
 
 5 
 
 15.00 
 
 
 32.00 
 
 4 
 
 9.20 
 
 
 37.80 
 
 3 
 
 1.70 
 
 
 45.30 
 
 T. P. 
 
 - 2.21 
 
 
 44.75 
 
 
 + 18.88 
 
 63.63 
 
 
 2 
 
 6.90 
 
 
 56.70 
 
 T. P. 
 
 - 2.24 
 
 
 61.39 
 
 
 + 18.31 
 
 79.70 
 
 
 1 
 
 15.50 
 
 
 64.20 
 
 
 
 4.40 
 
 
 75.30 
 
 towards Station 1 far ienough to descend an amount equal 
 to 48.8 — 45.0 = 3.8 ft. As the rate of fall is 1 in 15.4, to 
 fall 3.8 ft. we must go 15.4 x 3.8 = 58.5 ft., which brings us 
 
MAPPING. 783 
 
 to contour 45. This distance we scale off to a scale of 
 100 ft. to the inch, marking the point where contour 45 
 crosses line y^ by a small dot. The next two lower contours 
 are 40 and 35. As the elevation of Station 1 is 42.3 and that 
 of Station 2 is 34.8, both of these contour lines will cross the 
 line between these stations. The total fall between Stations 
 
 1 and 2 is 42.3 - 34.8 = 7.5 ft., and the rate of fall is ^ = 
 
 13.3. To reach contour 40 we must fall 2.3 ft. below Station 
 1, and the distance will be 2.3 X 13.3 = 30.6 ft. To reach 
 contour 35 we must fall 5 ft. more, and the additional dis- 
 tance will be 5 X 13.3 = 66.5 ft. We accordingly locate 
 those contours at 30.6 ft. and at 30.6 + 66.5 = 97.1 ft. from 
 Station 1. The difference of elevation between Stations 2 
 and 3 is 34.8 — 25.7 = 9.1 ft., and equivalent to a de- 
 scending slope of 1 to 11 between them. Contour 30 will 
 come at 4.8 X 11 = 52.8 ft. from Station 2. The difference 
 of elevation between Stations 3 and 4 is 25.7 — 18.3 = 7.4 ft., 
 which gives a descending slope of say 1 to 14. This is not 
 the exact rate of slope, but where decimal fractions are small 
 and slopes easy the fractions may be ignored, as they will not 
 to a perceptible degree affect the accuracy of the work. Con- 
 tour 25 will come at 14 X .7 = 9.8 ft. from Station 3, and 
 contour 20 at a point 70 ft. farther, or at say 80 ft. from 
 Station 3. The difference of elevation between Stations 4 
 and 5 is 18.3 — 16.1 = 2.2, but no contour line passes between 
 these points. The difference of elevation between Stations 
 5 and 6 is 16.1 — .5 = 15.6, which gives a slope of 1 to 6.4. 
 This brings contour 15 at 7 ft., contour 10 at 39 ft., and 
 contour 5 at 71 ft. from Station 5. 
 
 1373. The usual custom is to -work up the notes, as it is 
 called, before commencing the platting of the contours, 
 and when a considerable portion of the ground has been 
 covered, plat them, and thus avoid the delay incurred by 
 frequent changes of work. Each engineer decides upon 
 that form of notes best suited to the character of the work 
 in hand. The following is a clear and simple form of notes 
 
784 
 
 MAPPING. 
 
 in which is given the location and elevation of the con- 
 tours on line B and on the cross-section lines between lines 
 A and B: 
 
 Line B. 
 
 Contours Between Lines 
 A and B. 
 
 Sta. to 1. 
 
 from A to B 0. 
 
 + 3 to contour 75 
 
 5 ft. to contour 50 
 
 + 48 to contour 70 
 
 24 ft. to contour 55 
 
 + 93 to contour 65 
 
 43 ft. to contour 60 
 
 
 62 ft. to contour 65 
 
 
 81 ft. to contour 70 
 
 
 97 ft. to contour 75 
 
 Sta. 1 to 2. 
 
 A 1 to B L 
 
 1 + 56 to contour 60 
 
 12 ft. to contour 45 
 
 
 34 ft. to contour 50 
 
 
 57 ft. to contour 55 
 
 
 79 ft. to contour 60 
 
 Sta. 2 to 3. 
 
 A 2 to B 2. 
 
 2 -f- 15 to contour 55 
 
 1 ft. to contour 35 
 
 2 + 59 to contour 50 
 
 23 ft. to contour 40 
 
 
 46 ft. to contour 45 
 
 
 68 ft. to contour 50 
 
 
 91 ft. to contour 55 
 
 Sta. 3 to 4. 
 
 A 3 to B 3. 
 
 3 + 04 to contour 45 
 
 21 ft. to contour 30 
 
 3 + 70 to contour 40 
 
 46 ft. to contour 35 
 
 
 71 ft. to contour 40 
 
 
 96 ft. to contour 45 
 
MAPPING. 
 
 785 
 
 Line B. 
 
 Contours Between Lines 
 • A and B. 
 
 Sta. 4 to 5. 
 
 A ito B i. 
 
 4+48 to contour 35 
 
 9 ft. to contour 20 
 
 
 34 ft. to contour 25 
 
 
 59 ft. to contour 30 
 
 
 84 ft. to contour 35 
 
 Sta. 5 to 6. 
 
 A 5 to B d. 
 
 6 + 17 to contour 30 
 
 24 ft. to contour 20 
 
 5 + 60 to contour 25 
 
 55 ft. to contour 25 
 
 
 86 ft. to contour 30 
 
 Sta. G to 7. 
 
 A 6 to B 6. 
 
 6 + 02 to contour 20 
 
 22 ft. to contour 5 
 
 6 + 29 to contour 15 
 
 47 ft. to contour 10 
 
 6 + 56 to contour 10 
 
 72 ft. to contour 15 
 
 6 + 83 to contour 5 
 
 97 ft. to contour 20 
 
 Sta. 7. 
 
 ^ 7 to B 7. 
 
 7 + 12 to contour 0, 
 
 95 ft. to contour 0, 
 
 at edge of lake. 
 
 at edge of lake. 
 
 1374. The student having worked up these notes can, 
 with a little practice, plat them rapidly, using a decimal 
 scale. A small offset scale is very convenient in locating 
 contours. The examples given in working up notes will 
 enable the student to similarly treat the others. He should 
 be systematic in his calculations and platting, completing 
 all the calculations on one line before commencing another, 
 and do likewise in his platting. Otherwise, confusion is 
 sure to follow. 
 
786 MAPPING. 
 
 The elevations of the ground at the intersections of the 
 division lines are given in the engraving. This is done for 
 the convenience and assistance of the student. In regular 
 office work the elevations of these points are taken from the 
 level book, and the only elevations given in the map are 
 those of the contours, which are written in gaps left in the 
 contours for that purpose. 
 
 These elevations should be distinctly written, and, unless 
 the slopes are very steep, bringing the contours very close 
 together, the elevations should be written successively one 
 above the other. In drawing the shore line, avoid the 
 drawing of straight, regular lines. All shore lines, and 
 especially those of lakes, are very irregular. A heavy line 
 is first drawn outlining the shore, then a lighter one, at a 
 small distance from, and parallel to, the first; then another 
 line, at a greater distance from the second than the second 
 is from the first ; and so on until the shore line is clearly 
 defined. 
 
 The contours themselves are to be drawn free-hand with 
 an ordinary writing pen. 
 
 1375. Second System — By Lines of Greatest 
 
 Slope. — Their direction is that which water would take in 
 running off them. They are drawn perpendicular to the 
 contour lines^ and are called hatchings. An example of this 
 system is shown in Fig. 343. 
 
 In sketching topography by this system, the topographer 
 should hold the book directly in front of him so as to corre- 
 spond with his position on the ground, drawing the lines 
 towards him. If at the top of a hill, begin by drawing the 
 lines from the bottom, and vice versa. To guide the hatch- 
 ings, he should lightly sketch in the contour lines. Hatch- 
 ings must be drawn truly perpendicular to the contour lines. 
 Where the contour lines curve sharply, it is often well to 
 draw in hatchings at considerable intervals as a guide to the 
 main body of those drawn afterwards. Hatchings in adjoin- 
 ing rows should not be contimious, but so drawn as to break 
 joints. They must not overlap, and should be drawn in 
 
MAPPING. 
 
 787 
 
 slightly ivavy lines. In drawing a hill where the slopes are 
 steep and irregular, it is often well to draw auxiliary 
 contours. 
 
 An example of this system is given in Fig. 3 of Plate, 
 Title: Contours and Slopes, which represents an abrupt 
 promontory. Its base marks the channel of a river. The 
 ground on the opposite side of the river is generally level 
 with occasional undulations. The degree of the slope is 
 indicated by the spacing of the contours and the correspond- 
 ing lengths and number of hatchings. The more abrupt 
 the slope the closer together the contours and hatchings. 
 
 Fig. 3-13. 
 The preliminary work necessary for such a topographical 
 map is as follows: A traverse or meander line is. run, mark- 
 ing the windings of the stream. Having platted this 
 meander line, the topographer takes his book containing 
 the sketch, and from the promontory itself sketches in the 
 main features of the surface. A hand level is of great ser- 
 vice in determining relative elevations. From these notes 
 the final map is made up, the work being done in the office. 
 Fine topographical drafting should not be attempted in 
 camp. The facilities of a well-equipped office are necessary 
 to rapid and satisfactory work. The student is not expected 
 
788 MAPPING. 
 
 to reproduce the exact outline of the figure^ but it is expected 
 that his work will show a proper understanding of the sub- 
 ject. Having drawn the outline of the river, he should 
 draw in the contours in light pencil lines, spacing them to 
 conform to the different slopes. It will be evident to the 
 student that within the space represented by Fig. 2 the sur- 
 face of the river at C and D will be practically the same. 
 Hence, if the distance from the summit A to the river at E 
 is but half the distance from A to F, the slope A E must be 
 twice as abrupt as the slope A F. Hence, the contours 
 which mark equal heights will be twice as far apart on the 
 slope A F as on the slope A E. He should draw all the 
 contours, outlining the summits at A and B^ before com- 
 mencing the hatchings. The short hatchings on either side 
 of the river mark its banks. On the promontory side they 
 are shorter than on the opposite side, as the former has the 
 more abrupt banks. Fig. 3 of the same plate represents 
 an irregular and abrupt sea coast. The survey for such an 
 area would embrace a traverse of the entire shore line — of 
 the island as well as the mainland. This traverse line 
 should be used as a base line for auxiliary traverse lines, by 
 means of which the summits A, B, C\ D, and E, and any 
 other important objects could be located. . The heights of 
 these summits could be determined either by triangulation 
 or by the aneroid barometer. With this information as a 
 basis, the shore line is located, the contours sketched in, and 
 the hatchings drawn. As in the case of Fig. 2, the student 
 is not expected to produce a literal copy, but to show his 
 proficiency by furnishing a clear and finished drawing. 
 
 Hatchings should have their thickness and distance apart 
 proportional to the steepness of the slope. The lines are 
 made heavier as the slope is steeper, being fine for gentle 
 slopes, and for very steep slopes the blank spaces are but 
 half the breadth of the lines. 
 
 1376. Third System— By Shades from Vertical 
 I^ight. — The steeper the slope the less light it receives. 
 In practice, the difference in color is much exaggerated. 
 
MAPPING. 
 
 789 
 
 Various governments have prepared tables establishing the 
 ratio of color to different slopes. The shading is applied in 
 various ways. A rapid method, and a sufficiently accurate 
 one for many kinds of work, is to sketch in the contours and 
 then apply the shading in the form of India ink. Each 
 varying tint is applied with its particular brush, care being 
 taken not to allow any tint to dry before the succeeding 
 tint is applied. By this means the tints are blended, giving 
 a smooth and finished effect to the work. The tints are 
 made light for gentle slopes and dark for steep slopes, a 
 slope of 60° being black and one of 30° being midway 
 between black and white, and so on. 
 
 1377. Shades by Contour Lines. — This is accom- 
 plished by interpolating additional contour lines between 
 the regular contours. Confusion is likely to result from 
 this method, especially where the slopes are steep, as the 
 numerous contours are liable to run together or be confused 
 with roads or boundaries. 
 
 CONVENTIONAL SIGNS. 
 
 1378. Sand, Rock, Etc. — Sand is represented by 
 fine dots made by the point of a pen ; gravel by coarser 
 dots. Rocks are represented by angular, irregular masses, 
 as would appear when seen from above and drawn in their 
 proper places. 
 
 1379. Signs for Vegetation. — Woods are repre- 
 sented by scalloped circles, irregularly placed, closSr or 
 
 ttU 
 
 %^^ 
 
 44i^ 
 
 ; i. / > 
 
 ill 
 
 11 
 ft 
 
 %%.%%% 
 
 ^*% ^^ "^V^^ Ms 
 
 %%<^<^^. 
 
 %<K%%A 
 
 ^\^^A. 
 
 Fig. 344. 
 
 Fig. 345. 
 
 Fig. 346. 
 
 farther apart, according as the forest is dense or open. 
 Their shadows are drawn on their lower right-hand sides, as 
 shown in Fig. :J44. Sometimes trees are drawn in elevation, 
 
790 
 
 MAPPING. 
 
 as shown in Fig. 345. This method is not admissible ac- 
 cording to the laws of projection, but it is very effective, 
 and deciduous trees are more readily distinguished from 
 evergreen by this method than by that shown in Fig. 344, 
 where deciduous trees are represented by scalloped circles 
 and evergreens by stars. 
 
 Orchards are represented by trees in regular rows, as 
 shown in Fig. 340. 
 
 Bushes are drawn like trees, but in smaller figures. Fig. 
 347 represents bushes and trees intermingled. 
 
 
 
 
 Fig. 347 
 
 FIG. 349. 
 
 Fig. 348. 
 
 Grass land is represented by irregular groups of short 
 diverging lines, as shown in Fig. 348. 
 
 Uncultivated land is shown by inter- 
 spersing the signs of sand, grass, bushes, 
 etc. ; cultivated land by parallel rows of 
 broken lines, as in Fig. 349. 
 
 Swamp land is represented by grass. 
 Fig 350 bushes, and water, as in Fig. 350. 
 
 1380. Shore Lines. — The sea-shore is represented by 
 a line following all its windings and indentations. 
 
 A short 
 
 FIG. 351. 
 
MAPPING. 
 
 Idi 
 
 distance from the shore line, a parallel line is drawn, and a 
 little further removed a second parallel, and so on, as in 
 Fig. 351. 
 
 An abrupt and rocky shore is shown in Fig. 352. The 
 irregular dotted surfaces surrounded by shore lines represent 
 
 •-ri: -.5^ 
 
 r^-<^.. 
 
 sand bars. The dotted outlines beyond the shore lines 
 represent either shoals or sunken rocks. 
 
 FIG. 353, 
 
 Rivers have their shore lines treated in the same manner 
 as the sea-shore, as shown in Fig. 353. 
 
 Large brooks are represented by two parallel lines; small 
 brooks by a single line. 
 
792 MAPPtlSTG. 
 
 1381. Grounds and Gardens. — Grounds and gar- 
 dens are represented in plan as follows: The grounds, by 
 boundaries of property and street lines; the house and other 
 buildings, by their ground plan, and drives, walks, lawn, 
 shrubbery, and trees, by either outlines or conventional 
 signs. The gardens by rectangular beds and other forms 
 of arrangement. 
 
 PLATE, TITLE : TOPOGRAPHICAL MAPS. 
 
 1382. Fig. 1 of this plate illustrates the use of conven- 
 tional signs in practical landscape gardening, affording the 
 student some knowledge of how a given area may be dis- 
 posed so as to combine artistic arrangement with practical 
 utility. It contains a plat of a house, grounds, and gardens 
 drawn to a scale of 50 feet to the inch. All necessary di- 
 mensions are given for an accurate reproduction of the 
 work. The student should first carefully study the outlines, 
 and accurately determine their dimensions, after which 
 the details will be a simple matter. 
 
 In drawing Fig. 1, first lay out the boundaries of the plat 
 of ground, 375 ft. front by 515 ft. deep. 
 
 The width of the street fronting the lot is 60 ft. From 
 the front corners of the lot A and A ', measure A B and A ' B\ 
 each 17^ ft., locating the center line of the carriage drive. 
 From B and B' measure ]00 ft., locating the centers C 
 and C. From these centers with equal radii C ^and C B' 
 describe equal arcs B D and B' D' containing 30°. Pro- 
 duce the radii C D and C D' until they intersect at E. If 
 the work has been correctly done, E will be equidistant 
 from the corners A and A' . Through E draw a line E E' 
 at right angles to the line A A'. This line will divide the 
 lot into two equal parts and form the main base line for the 
 location of points in the plat. With the radius E D 181 ft. 
 in length describe the arc D D\ completing the center line 
 of the front carriage drive. The drive is 15 ft. in width. 
 The inner boundary is described by simply reducing the 
 length of the radius 7^ ft., and the outer boundary by in- 
 creasing the length an equal amount. We next measure 
 
MAPPING. 793 
 
 from the street corner A on the left boundary the distance 
 A F= 300 ft., and at F draw F F' perpendicular to A F. 
 At some point G of the main base line E F', draw G G' 
 perpendicular to E E' and 95 ft. in length. At G', the ex- 
 tremity of this perpendicular, draw a line H H' perpen- 
 dicular to 6^ 6"' intersecting F F' at /, which point is the 
 center of an elliptical curve in the carriage drive. The 
 major axis K K' oi this ellipse is 85 ft., and the minor axis 
 L L is GG ft. in length. This ellipse the student will draw 
 according to the method described in the section on Me- 
 chanical Drawing. Having drawn the ellipse, the student 
 will readily draw the border lines of the drive by increas- 
 ing or reducing the lengths of the various radii. 
 
 Draw both outer and inner boundaries of the ellipse in 
 pencil so as to form closed figures. From some point M 
 of the street line draw MM' 213 ft. in length and parallel 
 to E E'. Through M' draw M' M\ perpendicular to E E'. 
 From E E' and M' M" locate the house from dimensions 
 given. From some point N oi E E\ draw A^ A^' 110 ft. in 
 length "and perpendicular to E E' . At N' draw in both 
 directions an indefinite line perpendicular to N N' . At some 
 point O of the line E E' erect a perpendicular O O' 35 ft. in 
 length, and through O' draw an indefinite line parallel to 
 E E'. From a point O' of this line with a radius of 100 ft. 
 describe an indefinite arc P P\ being careful that the 
 extremity ■/* shall be in a tangent to the center line at the 
 carriage driveway. Then, from some point Q, found by 
 trial, with a radius of 50 ft. , describe an arc P' N' which shall 
 be tangent to the straight line through A^' and the arc P P'. 
 In a similar manner find centers at the points 7?, S, T, and U, 
 from which with the given radii describe arcs forming the 
 center line of the carriage driveway. Having located the 
 center line complete, the boundaries are put in as previously 
 directed, being careful to unite the various curves with 
 smooth, even lines. The arc described from the center U 
 must be tangent to the ellipse and to the center line V V, 
 which is 15^ ft. distant from the boundary of the lot. The 
 stable lot is 75 ft. square. The buildings may be readily 
 
794 MAPPING. 
 
 located from figures given in the drawing. The kitchen 
 garden extends from the rear boundary of the lot 150 ft. 
 towards the street, and from the right-hand boundary to the 
 driveway and stable yard. It is divided into rectangular 
 plots, the various sizes being suited to the character of 
 the vegetables grown. All dimensions necessary for a 
 reproduction of the drawing are fully given. 
 
 1383. Fig. 2 shows a portion of a town, together with 
 its connections with railroad and canal. The student will 
 make the drawing to a scale of 200 feet to the inch. 
 
 Before commencing this plate the student will note that 
 the magnetic meridian is parallel to the rightand left borders 
 of the plate. At 250 ft. from the S W corner of the plat 
 we locate a plug, which is the starting point for the traverse 
 of the river. Call this plug Sta. 1. Thence, run N 22° 30' E 
 734 ft. to Sta. 2; thence, N G0° 30' E 57G ft. to Sta. 3, the 
 center of Main street; thence, N 68^ 1 5' E 430 ft. to Sta. 4. 
 At 100 ft. from the starting point the river is 30 ft. to 
 right ; at Sta. 2 it is 70 ft. R. ; at Sta. 3, 40 ft. R. ; at Sta. 4. 
 44 ft. R. The river has an average width of 400 ft. The 
 student will draw in the shore line from the offsets given 
 above, giving it the same contour as shown in the plate. 
 The opposite shore the student will locate by offsets, avera- 
 ging 400 feet each. Again starting at Sta. 3 of the river 
 traverse, a line is run N 16° W along the center of Main 
 street, producing the line backwards from Sta. 3 across the 
 river and beyond to the boundary of the plat. The several 
 lines of survey will be used as base lines for the location of 
 streets, railroad tracks, canal, and all objects included in the 
 map. The starting point of each line of survey is numbered 
 zero, and all lineal base-line measurements are referred to 
 the starting or zero points. Distances measured on the base 
 line are expressed in stations of 100 ft. each, and offsets are 
 given in full. Calling Sta. 3 of the river traverse 0, we 
 measure northward to Sta. +90, the north end of the river 
 and canal bridge. The wing walls of the abutments diverge 
 at an angle of 30°. At Sta. 4 + 93 is the center of the track 
 
MAPPING. 795 
 
 of the P. & N. R. R., the bearing of which is N 73° 
 30' E. 
 
 At Sta. 5 + ^8 is the center of Putnam street, the bearing 
 of which is N 73° 30' E. At Station 11 + 68 is the center 
 of Randolph street, the bearing of which is N 73° 30' E. 
 Produce the center lines of both Putnam and Randolph 
 streets until they intersect the boundaries of the plat. Main 
 street is GO feet in width, and Putnam and Randolph streets 
 are each 50 feet in width. Draw parallels to the center lines 
 of these streets, locating the proper boundaries as shown in 
 the plat. From the intersection of the center line of Mam 
 with that of Putnam street, measure eastward on the center 
 line of Putnam street 450 ft. to the center of Tyler street, 
 the bearing of which is N 3° 45' W. Produce the center line 
 of Tyler street northward until it intersects the north bound- 
 ary of the plat. On the N E corner of Main and Randolph 
 streets is a hotel fronting 110 ft. on Main and 100 feet on 
 Randolph streets. The hotel has a depth of 60 feet from 
 each frontage. On the S W corner of Main and Randolph 
 streets is the postoffice, fronting 60 ft. on Main street and 
 40 ft. on Randolph street. Returning to the starting point, 
 viz., Sta. 3 of the river traverse, and running southward on 
 the center line of Main street, at Sta. + 34 is the center 
 of the shore pier, 10 ft. by 40 ft. ; at Sta. 2 + 34 is the center 
 of the channel pier, 12 ft. by 40 feet, and at Sta. 4 + 34 is 
 the south end of the bridge. The bridge is 30 feet wide. 
 The wing walls of the south abutment also diverge at an 
 angle of 30°. The south approach is 40 ft. in width and 200 
 ft. in length. Beyond the approach the street has the full 
 width of 60 feet. 
 
 At 100 ft. east of the S W corner of the plat is the cen- 
 ter line of the S. & B. R. R., which has a double track, the 
 track centers being spaced 13 ft. apart. The bearing of this 
 tangent is N 15° 15' E, and the given point is numbered 
 Sta. 0. At Sta. 5 is the center of the towing path of the 
 C. & O. canal, the bearing of which is N 54° 30' E. At 
 Sta. 9 + 44.1 is the P. C. of a 6° curve L. for 30°. The 
 student will produce the center line to Sta. 12, which is the 
 
796 MAPPING. 
 
 point of intersection for the curve, laying off the tangent 
 distance of 255.9 ft. Draw the center line of each track, 
 spacing them 6.5 ft. from the main center line. Having 
 located the center of the 6° curve, the parallel curves are 
 struck with a compass, increasing the radius 6.5 ft. for the 
 outer curve and diminishing it the same amount for the 
 inner curve. North of Putnam St. the right of way of the 
 S. & B. R. R. is 100 ft., 50 ft. each side of the main center 
 line. Parallel to this center line on each side of the railroad 
 is a street 40 ft. in width. Produce the center line of the 
 ea^ track of the S. & B. R. R. until it intersects the center 
 line at the P. & N. R. R. The intersection angle is 57° 30'. 
 Unite these tangents by a 10° curve. At Sta. 6 + 63 of the 
 S. & B. R. R. west track, is the P. C. of a 16° curve L. for 
 27°, which we call track A. 
 
 At 40 ft. from the P. T. of this curve is the center of a 
 turntable, the diameter of which is 60 ft. From the cir- 
 cumference of the turntable to the inner wall of the round- 
 house is 60 ft. The right-hand end wall of the roundhouse 
 faces on a radial line from the center of the turntable, which 
 line makes an angle of 30° 30' with the tangent of the turn- 
 out curve. The left-hand end wall is similarly situated, 
 making an angle of 91° 30' with the tangent of the turnout 
 curve. The depth of the stalls is 70 ft. The tracks at the 
 inside wall line are spaced 15-ft. centers.* From the center 
 of the outside track to outside of end walls is 10 ft. At 
 Sta. 8 + 92 of the west track is the P. C. of a 16° turnout 
 curve, to left, for 30° 10'. This we call track B. The P. T. 
 is on the line of the south end wall of a car shop. The side 
 walls of the car shop are parallel to the tangent of the curve. 
 The east wall is 15 ft. from the center line of the tangent 
 and the west wall 50 ft., giving a total width of 65 ft. The 
 length of the car shop is 200 ft. At the northwest corner of 
 the car shop is an engine and boiler house 40 ft. square. 
 
 On the north side of Putnam street is a foundry, fronting 
 120 ft. on Putnam street and 175 ft. on Foundry street, the 
 building having a depth of 50 ft. from both frontages. The 
 east side of the building is parallel to the tangent of the 
 
MAPPING. 797 
 
 turnout curve leading to the car shop, and 10 ft. from it. 
 At Sta. 11-]- 55, as measured on the produced tangent of 
 the S. & B. R. R. is the south end of the platform of the 
 R. R. station. At Sta. 12 is the south end of the station 
 proper. The station is G7 ft. long, as measured on this tan- 
 gent. The outer edge of the platform is 8 ft. from the cen- 
 ter line of the adjacent tracks. The platform is 10 ft. wide 
 and extends on all sides of the station, the curved walls of 
 which are parallel to the railroad tracks. 
 
 At Sta. 8 of the S. & B. R. R. is the P. C. of a 1G° turn- 
 out curve R., which leads from the east track, containing 
 39° 50', and called track C. A tannery, 300 ft. in length by 
 90 ft. in width, extends from the P. T. of this curve, parallel 
 to and 20 ft. to the right of the center line of the tangent. 
 A bark shed of the full width of the tannery forms a con- 
 tinuation of the tannery and extends to Main street. A 
 platform 10 ft. in width extends the entire length of the 
 tannery, between it and the tracks. At the southwest cor- 
 ner of the tannery is an engine and boiler house 50 by 80 ft. 
 At GO ft. from the P. C. of track C and tangent to that 
 curve, track D commences. 
 
 At 54 ft. from the commencement of track D is the P. C. 
 of a 23° curve R. for 28° 38', and called track E, which ter- 
 minates in a tangent parallel to the tangent of track C, and 
 spaced 12 ft. from it. At 364 ft. from the P. T. of track 
 £ is the west end of a coal chute. The south side of the 
 chute is 8 ft. from the center of the track; the north side 
 is 22 ft. from the center of the track, which gives the build- 
 ing a total width of 30 ft. It extends in length to Main 
 street. At 257 ft. from the commencement of track D is 
 the P. C. of a 1G° curve R. for 31°, and called track F. At 
 8 ft. to the right and parallel to the tangent of this curve 
 is a freight depot, extending from the P. T. of the curve and 
 200 ft. long by 35 ft. wide. On the south side the freight 
 station is a platform 10 ft. wide, extending its entire length. 
 At 312 ft. from the commencement of track D is the P. C. of 
 a 23° curve R. for 31°, the tangent of which is parallel to 
 track F, their center lines being spaced 12 ft. 
 
798 MAPPING. 
 
 Between Sta. 5 + 78 of the S. & B. R. R. west track, and 
 Sta. 7 + 51, east track, is a cross-over track, which we call 
 track G. Thi» consists of two turnout curves, one com- 
 mencing at each of the given stations and intersecting on 
 the main center line. The curve commencing at Sta. 5 + 78 
 is a 9° 30' curve R. ; the curve commencing at Sta. 7 + 51 is 
 also a 9° 30' curve R., but described in the opposite direc- 
 tion. If carefully drawn, these curves will intersect on the 
 main center line. Between Sta. 14 + 44.1, east track, and 
 Sta. 16 + 17.1, west track, is another cross-over, which we 
 call track H. The curves are both 9° 30', described in 
 opposite directions, as in the preceding case. 
 
 Starting at Sta. 5 of the S. & B. R. R., which is directly 
 over the center line of the towpath of the C. & O. canal, 
 the bearing of which is N 54° 30' E, we measure north- 
 eastward along the center line of the towpath 706 ft. to the 
 P. C. of a 12° R. for 12°. Produce the back and forward 
 tangents of this curve until they intersect the borders of 
 the plat. The towpath is 12 ft. wide and the canal 40 ft. 
 wide. The canal makes the same curve as the towpath, the 
 arcs being struck from the common center. The student 
 will draw the boundaries of the canal and towpath in ink, 
 but need not ink in the center line of the towpath. The 
 north abutment of the Main St. canal and river bridge is 
 4 ft. from the boundary of the canal. At 443 ft. from our 
 starting point on the towpath is the west end of a canal 
 dock, which consists of a widening of the canal in which 
 boats are moored while their cargoes are being dis- 
 charged. This dock is 240 ft. long and 20 ft. wide, provi- 
 ding berths for four boats. At 120 feet from the west end of 
 the dock is the west end of a coal chute, the south side of 
 which is parallel to and 20 ft. from the dock. The coal 
 chute is 40 by 200 ft. The railroad bridge over the canal is 
 30 ft. wide. The south abutment is placed 12 ft. and the 
 north abutment 6 ft. from the canal, both abutments being 
 parallel to the canal. The outer faces of the wing walls of 
 these abutments are parallel to and 10 ft. from the center 
 line of the nearest track. 
 
MAPPING. 799 
 
 PLATE, TITLE: MAP OF A VILLAGE. 
 
 1384. This plate represents a topographical map of a 
 village. In making a survey of this description the engineer 
 will select for a starting point some well-defined landmark ; 
 but as there are a score of points to choose from, the choice 
 will depend upon the judgment of the engineer. The in- 
 tersection of the center lines of two highways or the head 
 block of a railroad switch are excellent points from which to 
 commence a survey. The center lines of highways and 
 railroads are the base lines from which the minor details, 
 such as houses and other buildings are located. The quickest 
 and best method of locating a building is to set a temporary 
 plug on the base line near the building. Set up the transit 
 at this point and measure the angles between the base line 
 and two consecutive angles of the building, measuring the 
 distances from the plug to the angles of the building. These 
 angles and distances will locate one side of the building. A 
 small free-hand sketch is then made, giving the base line, 
 the station of the plug, or its distance from some known 
 point, and the angles and distances to the side of the build- 
 ing. The remaining sides of the building are added to the 
 sketch and their several lengths measured in consecutive 
 order and marked on the sketch. These notes are quickly 
 made and as quickly platted. 
 
 Sketches are of the greatest value in taking topographical 
 notes. They can be made in less than half the time re- 
 quired for a full description, and are always more intelligi- 
 ble to the draftsman. Each surveyor has his individual 
 methods, both in order of work and form of notes, and 
 often one will consume twice as much time as another in 
 performing the same work ; but expedition is of no value if 
 had at the cost of accuracy. 
 
 In this map all the conventional signs suited to an area of 
 such magnitude are employed. The student will draw the 
 map to a scale of 200 feet to the inch. The magnetic merid- 
 ian is parallel to the right and left borders of the plate, 
 the north point being at the top of the map. The center 
 lines of the highways are given, together with their mag- 
 
800 MAPPING. 
 
 netic bearings, widths, and distances between the angles 
 made by the center line. The center line of the railroad is 
 represented by a heavy, full line, and the boundaries of the 
 right of way, which is 100 feet in width, are represented by 
 light full lines. The magnetic bearings of the tangents are 
 given and the stations of the points of curve and tangent 
 from which the lengths of the tangents are found by sub- 
 tracting the station of the P. T. of one curve from the 
 P. C. of the succeeding curve. The curves, instead of 
 being run in from intersections of tangents, are platted as 
 follows: 
 
 The location of the first tangent in the map being given 
 by references to the boundary lines of the map, and the 
 P. C. of the first curve denoted by its station, a perpendicu- 
 lar is erected to the given tangent, and upon it the length 
 of the radius of the required curve is laid off to the given 
 scale. Then, from the given center the curve is struck with 
 a compass, being careful that the arc so struck shall contain 
 as many degrees as the central angle of the curve, the 
 central angle of the curve being laid off with a protractor. 
 The intersection of the second radius with the arc will be 
 the P. T. of the following tangent. A perpendicular is then 
 erected to the second radius and tangent to the arc at the 
 given intersection. The P. C. of the next curve being given, 
 its length is readily found by subtraction. The borders of 
 the lake are located by offsets. 
 
 The student is not expected to exactly duplicate the 
 topography, but give the same general effect. All bound- 
 aries whose magnetic bearings are given and the location of 
 all buildings he must faithfully repeat in his drawing. 
 
 1385. Starting at the northwest corner K of the map 
 we measure eastward along the north boundary TOO ft. to 
 Z, the center of the S. & L. R. R., the bearing of which at 
 that point is S 7° 45' E. At 310 feet from this point is the 
 P. C. of an 8° curve R., which we call Sta. 40 + 60. The 
 central angle of this curve is 25°, and its length 312.5 ft 
 The station of the P. T. we find by adding the length of the 
 
MAPPING. 801 
 
 curve to the station of the P. C, giving 43 + 72.5 for the 
 P, T. of the curve. The bearing of the forward tangent is 
 S 17° 15' W and its length 400 ft., making the station of 
 the next P. C. 47 + 72.5. This curve is 9° R. and its central 
 angle is 15". Its length is, therefore, 1G6.7 ft., and the sta- 
 tion of the P. T. 49+39.2. The bearing of the forward 
 tangent is S 32° 15' W, found by adding the central angle 
 of 15° to the bearing of the preceding tangent. The length 
 of the forward tangent is GIO ft. to Sta. 55 + 49.2, which is 
 the P. C. of a 6° curve L. The curve is continued to the 
 south boundary of the map. 
 
 The switch extending to the ice houses along the shore of 
 the lake is located as follows : 
 
 Scale off from the northwest corner K of the map, along 
 the north boundary 790 ft., eastward to the point M. From 
 this point as a center, lay off with a protractor to the right 
 of the north boundary an angle of 32° 30'. The bearing of 
 this line is S 57° 30' E. Scale 47 ft. on this line from the 
 point in the boundary where the angle is turned. This will 
 locate the P. C. of a 16° curve R., the station of which is 
 3 + 04.7. The central angle of this curve is 62° 05', and the 
 station at the P. T. 6 + 92.7. The bearing of the forward 
 tangent is S 4° 35' W. The next curve is 10° R. Its P. C. 
 is at Sta. 10+93.7, and its central angle is 9" 40', which 
 brings the P. T. at Sta. 11 + 89.4. The bearing of the for- 
 ward tangent is S 14° 15' W. The next curve is also 10° R. 
 Its P. C. is at Sta. 15 + 49.4, and its central angle 27° 30', 
 which brings the P. T. at Sta. 18 + 24.4. The bearing of 
 the forward tangent is S 41° 45' W. The last curve is 10° 
 L. Its P. C. is at Sta. 24 + 24.4, and its central angle is 
 27° 10', which brings the end of the line at Sta. 26 + 96.1. 
 
 With a protractor lay off from the P. C. of the 16° curve 
 of the ice switch, a central angle of 18°. Draw a radius in- 
 cluding this angle and at its extremity draw a tangent to 
 the curve, with bearing of S 39° 30' E. This point of tan- 
 gent is the starting point of a switch leading to a coal chute. 
 This point we call Sta. 0. At Sta. + 65 of this track is the 
 P. C. of an 18° curve R. for 36°, bringing the P. T. at Sta. 
 
802 MAPPING. ' 
 
 2 + 65. At this point the track enters a coal chute 50 ft. long 
 by 30 ft. wide. The center line of the track is parallel to 
 the sides of the chute and spaced 7 ft. from the west side. 
 At 120 ft. from the starting point of the S. & L. R. R. is the 
 north end of platform of a railroad station, and at 210 ft. from 
 that point is the south end of the platform. The edge of this 
 platform is spaced G ft. from the center line of the railroad 
 track. The platform is 46 ft. in width at the north end and 
 50 ft. in width at the south end. The center line of a road 
 40 ft. wide commences at the middle point of the south end 
 of the railroad station platform, and extends in the direc- 
 tion S 48° 30' E 500 ft., where it intersects with the center 
 line of the Scranton turnpike, the bearing of which is S 21° 
 30' W. Call this point of intersection A. 
 
 Starting from intersection A, the traverse of the center 
 line of the turnpike is as follows: S 21° 30' W 310 ft.; 
 thence, S 58° 30' E 80 ft. to the west end of a bridge 20 ft. 
 wide; thence, by same course 40 ft. to east end of bridge; 
 thence, by same course 80 ft. to an intersection with center 
 line of Andrews lane. Call this point of intersection B. 
 Thence, S 11° 30' W 300 ft. to intersection with center line 
 of Waverly road. Call this point of intersection C. Thence, 
 by same course 300 ft. ; thence, S 8° 30' E 250 ft. ; thence, 
 S 27° E 345 ft. to north end of a stone bridge 20 ft. wide; 
 thence, by same course 30 ft. to south end of stone bridge ; 
 thence, by same course 125 ft. to an intersection with the 
 center line of Newton road, the direction of which is N 63° 
 E and width 40 ft. Call this intersection point D. From 
 intersection D the turnpike extends in the direction N 83° E 
 400 ft., thence, S 76° E 325 ft.; thence, S 46° E to the 
 south boundary of the map. The width of this turnpike is 
 50 ft. 
 
 Next we measure from the northwest corner K of the 
 map, southward along the west boundary 344 ft. to the cen- 
 ter A^ of the Benton road. From thence we measure along 
 the center line of the road, N 80° 15' E 356 ft. : thence, 
 S 69° 45' E 350 ft. ; thence, S 89° 45' E 45 ft. to west end of 
 a culvert 2^ ft. in width; thence, by same course, 50 ft. tq 
 
MAPPING. 803 
 
 east end of culvert; thence, by same course, crossing the ice 
 switch and road leading to the railroad station and continu- 
 ing to an intersection with the Scranton turnpike, which is 
 the terminus of the Benton road. Call this point of inter- 
 section E. 
 
 Starting at intersection C, we follow the center line of the 
 Waverly road as follows: S 55° 15' E 197 ft. to its intersec- 
 tion with the center line of Lenox lane. This point of in- 
 tersection we call F. Thence, N 74° 45' E 500 ft. ; thence, 
 S 85° 15' E, intersecting the old Scranton and Montrose 
 turnpike and extending by the same course to the east 
 boundary of the map. 
 
 Returning to the point F^ the intersection of the center 
 line of the Waverly road with Lenox lane, we prolong 
 the line C F from F, a distance of 290 ft» This forms the 
 center line of Lenox lane, and intersects with the center line 
 of Henderson lane. These intersecting center lines form 
 an angle of 90° with each other, making the course of 
 Henderson lane N 34° 45' E. Produce the center line of 
 this lane in both directions, intersecting on the south with 
 the Scranton turnpike, and on the north with the Waverly 
 road. The widths of the Waverly road and Lenox and 
 Henderson lanes are each 40 ft. Commencing at the point 
 B, where the Scranton turnpike intersects the center line of 
 Andrews lane, we follow the center line of that lane in the 
 direction N 31° 30' E 300 ft. to an intersection with the cen- 
 ter line of a private lane leading in the direction S 85° 30' E 
 200 ft., where it turns at right angles, 40 ft. to the right 
 and 75 ft. to the left. Continuing along the center line of 
 Andrews lane by the same course 100 ft., we change the 
 direction, running N 11° 30' E, intersecting with Hall road. 
 The width of Andrews lane is 30 ft. 
 
 Starting from the southeast corner O of the map, we 
 measure westward along the south boundary 320 ft. to the 
 center /'of the old Scranton and Montrose turnpike. From 
 this point we follow the center line of the turnpike as fol- 
 lows: N 27° 45' W 440 ft.; thence, N 7° 45' W 330 ft.; 
 thence, N 2° 15' E 1,280 ft., intersecting the Waverly and Hall 
 
804 MAPPING. 
 
 roads. The latter intersection makes the eastern limit of 
 Hall road. Thence, N 5° 45' W to the north boundary of 
 the map. The width of this turnpike is 50 ft. Returning 
 to point E^ the terminus of the Benton and Hall roads, we 
 follow the center line of Hall road S 89° 45' E 1G5 ft. to the 
 west end of a bridge 20 ft. wide ; thence, by same course, 
 30 ft. to east end of bridge; thence, by same course, 400 
 ft. to an intersection with the center line of Prospect road, 
 which extends in the direction N 40° 15' E to the north 
 boundary of the map. Call this point of intersection G. 
 From the point G the center line of Hall road extends in 
 the same direction, viz., S 89° 45' E to its intersection with 
 the center line of the old Scranton and Montrose turnpike. 
 Call this intersection point H. The widths of the Hall and 
 Prospect roads are 40 feet. 
 
 The right of way of the S. & L. R. R. is 100 ft. in width, 
 50 ft. each side of the center line, excepting at the station, 
 where the railroad company's property extends in width 100 
 ft. on the east side from the center line of the track, and in 
 length from the north boundary of the map to the highway. 
 On the west it extends in width 200 ft. from the center line 
 of the track and in length from the north boundary of the 
 map to the Benton road. At a point 390 feet from Sta. 
 43 + 72.5 of the main track, as measured on the west right 
 of way boundary, is the end of the boundary line between 
 lands of James Henderson and John Andrews, the bearing 
 of which is S 57° 45' E. This boundary extends to the west 
 boundary of the map. At a point in the center of Hall 
 road, 10 feet west of intersection G, is a corner at the 
 schoolhouse lot which fronts 100 feet on Hall road, and 220 
 feet in depth, as measured from the center line of the road, 
 the sides being at right angles to the center line of the road. 
 All property lines bounding on or intersecting higlnvays follow 
 or extend to the center line of the highway. Immediately 
 adjoining the schoolhouse lot on the west is the lot of John 
 Stark, with front of 200 ft. and depth of 220 ft. A point 
 300 ft. east of intersection 6", as measured on the center 
 line of Hall road, is a corner of lot of F. Swartz. This 
 
MAPPING. 805 
 
 boundary is at right angles to the center line of Hall road 
 and extends to the center of Prospect road. The other 
 boundaries of the lot are marked by the center lines of the 
 roads upon which the lot fronts. At a point 300 ft. south 
 of intersection //, as measured on the center line of the old 
 turnpike, is a corner of lot belonging to John Edwards. 
 The sides of the lot are at right angles to the center line of 
 the turnpike and the ends parallel. The lot fronts 300 ft. 
 on the turnpike and has a depth of 425 ft. The south 
 boundary of this lot forms a part of the north boundary of a 
 lot belonging to Jane Gregory. A line joining the south- 
 west corner of John Edwards's lot with the northeast corner 
 of Henry Watson's lot completes the north boundary of the 
 Gregory lot. The bearing of this line is N 87° 10' E. The 
 west boundary has a bearing of N 4° 45' E, and extends to 
 the center line of Waverly road, with which it forms an 
 angle of 90°. The south and east boundaries of the lot are 
 formed by the center line of the Waverly road and the old 
 turnpike, the courses of which are already given. The 
 point of intersection of the center line of the Waverly road 
 with the old turnpike is a corner of lot belonging to A. 
 Atherton. The north boundary extends along the center 
 line of Waverly road 425 feet; thence, at right angles to 
 that road, S 4° 45' W 420 ft. ; thence, on a line parallel to 
 the Waverly road, to the center of the old turnpike. The 
 west boundary is formed by the center line of the turnpike. 
 The west boundary of lot belonging to Jane Gregory 
 forms the east boundary of lot belonging to Henry Watson, 
 which has a frontage of 150 feet and a depth of 220 feet. 
 The west boundary of Henry Watson's lot forms the east 
 boundary of lot belonging to James Lenox, and extends 
 N 4° 45' E 220 from the center of the Waverly road. 
 Thence, N 85° 15' W to the center of the Scranton turn- 
 pike. The remaining boundaries of the Lenox lot are 
 formed by the center lines of the adjoining highways. By 
 prolonging the boundary between Henry Watson and James 
 Lenox northward 275 feet, we form the east boundary of 
 John Andrews's lot. The same line prolonged to the center 
 
806 MAPPING. 
 
 of Hall road forms the east boundary of Clayton Andrews's 
 lot. The boundary between lots of John and Clayton 
 Andrews is formed by the center line of the lane, and that 
 center line produced to the east boundary of the lots. The 
 remaining boundaries of these lots are formed by the center 
 lines of the adjacent highways. At 210 feet from inter- 
 section Cy as measured on the center line of the Waverly 
 road and Lenox lane, is the northwest corner of a lot belong- 
 ing to the Lenox estate. This lot has a front of GO feet and 
 a depth of 180 feet, the sides being at right angles to the 
 center line of Lenox lane. 
 
 All buildings the student will locate by eye, giving to 
 them the same shape and proportions as shown in the plate. 
 Shade trees are spaced 50 feet, their rows being placed 
 10 feet inside the road boundaries. Fruit trees are spaced 
 40 and 30 feet. The usual conventional signs are employed 
 to represent the topography. As grass and cereals are much 
 alike in appearance, the conventional sign for grass may be 
 varied so as to represent them all and so give variety to the 
 drawing. A part of the lot belonging to James Henderson 
 is occupied by a vineyard, which is represented by rect- 
 angles enclosed in wavy outlines. These signs might also 
 be used to represent small fruits growing on trellises. All 
 other conventional signs employed have been previously 
 described, with appropriate illustrations. 
 
 1 386. Colored Topography. — All conventional signs 
 so far described are made with a pen. Often, where sur- 
 veys cover extensive areas, the labor and time for pen work 
 can not be spared, and colors applied with a brush are used 
 instead. With a skilful hand, work of this character may 
 be rapid and very effective. But three colors besides India 
 ink are required; gamboge (yellow), indigo (blue), and lake 
 (scarlet). The colors used in the drafting room are of 
 two kinds, viz., dry and moist. Dry colors are sold in the 
 form of rectangular cakes, wrapped in tin foil. Moist colors 
 are packed in small dishes of porcelain. These dishes are 
 rectangular in form, open at top. The surface of the paint 
 
MAPPING. 807 
 
 is covered with wax and the entire dish wrapped in tinfoil. 
 In using, rub the cake of color with a moistened brush 
 which will take up sufficient color. Dilute the color in 
 water to the proper tint, which should always be light and 
 delicate. To cover a surface with a uniform tint, use a 
 camel's hair or sable brush. Use a separate brush for each 
 tint and provide plenty of dishes for the various colors. 
 Confusion in the use of brushes is sure to spoil a tint. For 
 large masses of the same tint, a large brush should be used, 
 but for vegetation or small details, small brushes are indis- 
 pensable. Avoid heavy strokes. Light and rapid strokes 
 produce smooth and pleasing effects. The map should be 
 pinned to a light drawing board, so that it may readily be 
 inclined at an angle. Keep the brush well filled with color 
 and begin at the top of the surface, inclining the board 
 towards you. If the outline is very irregular, moisten 
 the edge with water. Apply the tint the full length 
 of the surface and continue it down the surface, 7iever 
 allowing the edge to dry, which is the secret of a smooth 
 tint. 
 
 Woods are commonly colored yellow; grass land, green, 
 made of gamboge and indigo; cultivated land, brown, made 
 of lake, gamboge, and India ink; brushwood, marbled green 
 and yellow; vineyards, purple, made of lake and indigo; 
 lakes and rivers, of light blue, with a darker tint at the 
 shore line; seas, dark blue, with a little yellow added; 
 marshes, the water blue, with patches of green applied hori- 
 zontally, and roads, dark brown. Woods may be made very 
 effective by drawing the trees, coloring the angle towards 
 the light (the upper left hand) with a touch of yellow, and 
 indigo on the opposite, or lower, right-hand side. 
 
 Skill and judgment in mixing and applying colors can be 
 acquired only by practice. When a combination tint, such 
 as brown, is required, the draftsman must estimate how 
 much coloring is required and provide accordingly. He is 
 liable to use too much color producing a heavy tint, which 
 is almost certain to become streaked when applied. A 
 separate brush should be used to take up each color, the 
 
808 MAPPING. 
 
 brush being moistened and rubbed on the cake. A tinting 
 dish of either glass or porcelain contains the water. The 
 brushes carrying the colors are dipped into the water, each 
 giving off its proportion of color. The water is then stirred 
 until every particle of color is dissolved. If the tint is too 
 light, add more color; if too heavy — a common fault — add 
 more water until the proper shade is obtained. Any tint is 
 deepened by repeating the application of it. When a tint is 
 to be shaded from light to dark, give the entire surface one 
 coat, which will give the lightest shade. Decide how many 
 coats are to be applied to produce the deepest tint and 
 divide the length of the surface into the same number of 
 equal spaces. Beginning at the top of the surface to be 
 shaded, apply a second coat, stopping one space from the 
 bottom. Then take a clean brush and dip it into clear 
 water and wash the edge of the second coat at its finishing 
 line, brushing downwards, taking up in the brush all excess 
 of coloring matter. Another coat is then applied, com- 
 mencing again at the top and stopping two spaces from the 
 bottom, washing down the edge with clear water. The 
 paper must not be allowed to dry between the successive 
 applications of the tint. If from any cause it should be- 
 come dry, the entire surface must be moistened with clear 
 water before another application of the tint. Careful prac- 
 tice will enable the student to produce a smooth tint. 
 When a marbled effect is desired, first cover the entire sur- 
 face with one tint and then apply the other in shorter or 
 longer strokes of the brush, according to the effect which it 
 is desired to produce. 
 
 In tinting shore lines, first trace the outline of the shore 
 with a brush moistened with clear water, extending the wash 
 as far as the tint is to be used. Prepare a color dark blue in 
 shade. Next dip a fine brush in the color and trace the out- 
 line of the shore. The adjoining paper being moist will cause 
 the color to run. Then moisten a brush in clear water and 
 wash the shore line, the strokes of the brush being drawn 
 from the shore. The effect will be a dark blue shore line 
 shaded to light blue. The dark brown color for roads is 
 
MAPPING. 809 
 
 produced by adding India ink to the brown representing 
 grass land, 
 
 1387. Scales. — The scale of a topographical map 
 should depend upon the character of the work involved, but 
 should always be large enough to clearly admit all necessary 
 details without making the map unwieldy. The work should 
 be so well done that dimensions may be accurately scaled 
 from the map without any calculation. For small plats, 
 such as public squares and small parks, 50 feet to the inch 
 would be a suitable scale, admitting the smallest detail. 
 For larger areas, such as town sites, extensive parks, sub- 
 urban resorts, etc., a scale of 200 feet to the inch is com- 
 monly used. The scale must be reduced in proportion as 
 the area is increased. Published topographical maps are 
 usually made to a scale of one inch to the mile, admitting 
 of the representation of all towns, villages, farms, woods, 
 isolated buildings, and every stream of 600 feet in length, 
 and every hill of 100 feet in height and 500 or 600 feet in 
 horizontal extent. 
 
 On a scale of two inches to the mile, the various features 
 of the ground can be clearly and accurately represented. 
 All streams of 300 feet in length, every pond not less than 
 50 feet broad, and all towns, villages, roads, foot-paths, 
 farms, and isolated buildings, 
 
 A scale of six inches to the mile is best for military pur- 
 poses, admitting of a complete delineation of a country. In 
 all cases the character of the surface and the purpose of the 
 map should determine the scale. 
 
 1388. Size of Maps. — Maps for use in the field may 
 vary in size from 18 by 24: inches to 24 by 30 inches. Both 
 sizes are suitable for railroad work. The lines should be so 
 arranged on the different sheets that they may be fitted 
 together, making a continuous map of the line of survey. 
 The sheets should be numbered in regular rotation, and 
 when pinned together they will appear as shown in Fig. 
 354. 
 
 Where possible, arrange the sheets so that each curve 
 
810 
 
 MAPPING. 
 
 with its center and limiting radii may come on the same 
 sheet. Sometimes this cannot be done. The points where 
 the different sheets join on to each other should be fixed by 
 a line drawn at right angles to the center line or radial line 
 
 l:^ 
 
 
 
 / 
 
 
 
 
 
 
 A . '? 
 
 
 
 ^^^^^^ 
 
 3 
 
 
 
 o 
 
 
 °f /(( 
 
 'i 
 
 k ,, 
 
 
 
 
 
 Br 
 
 V. 1 
 
 "■-J-—* 
 
 
 \C^ \ 
 
 
 o III 
 
 -■!' 
 
 o 
 
 
 L=>'«=« 
 
 
 
 \ 
 
 ,yA 
 
 \~^'''--i 
 
 
 \^-\^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Fig. 354. 
 at the point of junction, as at A or B. This simplifies the 
 work of fitting the sheets and greatly promotes accuracy. 
 
 1389. Lettering. — Legibility and uniformity are the 
 requisites for good lettering. Ornamental letters, ex- 
 cepting for titles, are entirely out of place, and they are 
 only admissible for titles of very elaborate maps. All let- 
 tering in the body of the map or details should be in 
 italics. Small letters should be two-thirds the height of 
 capitals, ordinary capitals | of an inch in height, and small 
 letters f of ^ or -^^ i^^h in height. Uniformity in spacing 
 letters is as important as uniformity in size. There is no 
 work where practice is more essential, if skill is to be ac- 
 quired, and nothing adds more to the finish of a drawing 
 than good lettering, while poor and slovenly lettering will 
 rob of all merit an otherwise perfect drawing. 
 
 1390. General Instructions. — If the entire map is 
 to be contained on a single sheet, judgment is required in 
 fixing the direction of the first course so as to attain that 
 result. The points of the compass must also be in their 
 
MAPPING. ■ 811 
 
 natural order, viz., North at the top of the map and South 
 at the bottom. 
 
 The outline of the map will determine the position of the 
 title. Yery fine lines are a blemish rather than a merit, and 
 heavy lines are likewise to be avoided except when used for 
 shading or boundaries. Boundaries of private property are 
 represented by bold, full lines, and those of state, county, 
 or municipality by heavy broken and dotted lines. All 
 dimensions should be expressed in figures, and all impor- 
 tant lines and objects briefly but accurately described. 
 
RAILROAD LOCATION. 
 
 1391. Need of a Railroad. — This subject presup- 
 poses that there is, beyond a doubt, need, both present and 
 prospective, for the railroad whose location is to be decided 
 upon. 
 
 1392. Available Capital.— The first duty of the 
 Chief Engineer is to know how much money those having the 
 direction of the enterprise, commonly known as tJic company, 
 have or can command, as all subsequent operations will be 
 governed by that fact alone. Having obtained that infor- 
 mation, he collects all available maps of the country to be 
 operated in, and from them derives a general knowledge of 
 the mountain ranges, valleys, rivers, together with their 
 tributaries, and the location of all towns and villages lying 
 within that territory, their relative size and importance. 
 
 1393. Terminals. — The terminals or extremities of 
 the proposed railroad are known, and the first problem be- 
 fore the engineer is to determine the general route which 
 the line connecting them should take. A careful study of 
 the maps in hand will indicate to him the different possible 
 routes whose comparative merits he can know only by care- 
 ful investigation. The number of these possible routes will 
 probably be further reduced by the location of certain towns 
 which must be reached for traffic considerations. These 
 towns will divide up the line into two or more sections, each 
 offering considerable range in choice of location, which in- 
 dicate to the engineer the scope of the country to be covered 
 by the reconnaissance. 
 
 1394. Important Considerations. — The engineer 
 should preserve an optimistic habit of mind, believing noth- 
 ing to be too difficult to be overcome, and fully expecting 
 
814 RAILROAD LOCATION. 
 
 to find a line in every way superior to that which had been 
 regarded as possible. It is of the highest importance that 
 he should regard the proposed line from a business point of 
 view, and be able to distinguish between what is commer- 
 cially important and physically important. He should keep 
 constantly in mind this vital fact, viz., that a line of rail- 
 road is built for the pifrpose of making money for its project- 
 ors; that any expenditure which will add proportionately to 
 the earning power of the road is wise^ and that any which 
 will not is criminal zaaste. 
 
 1395. Relative Economy. — The engineer must, 
 however, be able to distinguish between wise and unwise 
 economy. Because a line is brought to sub-grade cheaply, it 
 is not necessarily economical grading. It requires an average 
 continuous cut and fill of 7 feet, with the usual proportion 
 of masonry, to equal the cost of the superstructure, i. e., 
 ties, rails, fastenings, and ballast, while the cost of rolling 
 stock, machinery, buildings, etc., of an active road, cost 
 nearly as much as roadbed and track complete. 
 
 1396. Towns and Terminals. — Towns, which are 
 always the main sources of traffic, and terminals, which, 
 besides being sources of traffic, are the main points of 
 traffic exchange, are considerations of vital importance to 
 the road. No expense within the possible reach of the com- 
 pany should be spared in reaching the heart of towns and in 
 providing the best traffic facilities. A small saving in time 
 and a small increase in comfort will, other things being 
 equal, secure the traffic. Where the new line comes into 
 competition with old and favored lines, no pains which tact 
 or ingenuity can devise should be spared to induce favor and 
 patronage. It is at such a juncture that tact and enterprise 
 count. No source of business, however insignificant, should 
 be overlooked, and every point gained should be held at any 
 reasonable cost. Provide ample terminal grounds at any 
 possible cost; with them a new road will have a hard fight, 
 while the lack of them places the road at a great disadvan- 
 tage from the first, and may cause its ruin. 
 
RAILROAD LOCATION. 815 
 
 1397. Comparative Cost of Different Lines. — 
 
 In order that the engineer may correctly estimate the com- 
 parative cost of different lines, he must know the actual 
 cost of work of various kinds, and be able, from his exami- 
 nations of the country, to properly classify it. Experience 
 in the location and construction of other lines will alone 
 enable him to decide between the comparative merits of the 
 different routes. 
 
 The almost universal fault of engineers is to underesti- 
 mate cost, a fault common to all persons who are about to 
 undertake construction of any kind. Experienced engineers 
 make it a rule to add 10 per cent, to the estimate which is 
 intended to cover all possible cost. 
 
 1398. Considerations Which Determine the 
 Route. — Traffic and engineering considerations will usually 
 reduce the possible routes to tivo if not to one^ thus narrow- 
 ing the field of operations. The work of reducing the traffic 
 and engineering possibilities of a section of country to their 
 lozvest terms is emphatically the work of the chief engineer, 
 and is embraced in that most important, though much mis- 
 understood, term, viz., the reconnaissance. Let the young 
 engineer keep prominently before his mind that the largest 
 half of a railroad survey is the reconnaissance. Let him 
 ponder well the varied interests and problems which con- 
 front him, and let him know his country before he drives a 
 stake. This knowledge can be had only by hard work and 
 a good deal of it. 
 
 RECONNAISSANCE. 
 
 1399. General Directions. — Having provided him- 
 self with the best available map of the section immediately 
 in hand, an aneroid barometer, and a guide who is familiar 
 with the section, the engineer is ready for a start. He 
 should avoid highways if he is to acquire the knowledge he 
 is seeking, as they give the traveler an erroneous impres- 
 sion of the character of the surrounding country. He un- 
 consciously believes because the " walking is good " that the 
 
816 RAILROAD LOCATION. 
 
 surrounding country is smooth and tractable, and obstacles 
 to railroad building few and insignificant. On the other 
 hand, by taking a cross-country route, he will be likely to 
 exaggerate those obstacles, simply because they have im- 
 peded his travel. All experience goes to prove that in 
 America, at least, the railways avoid the highways; not 
 through the intent of the engineer, but, as it were, in silent 
 condemnation of the incapacity of those who directed their 
 building. The engineer should keep constantly in mind 
 that his examinations are not to be confined to the strip of 
 country within his immediate vision, but are to cover a 
 range of several miles on either side of his line of march. 
 Much information he can obtain from his guide; more he 
 must find out for himself — taking nothing for granted where 
 a doubt is raised. Very often an apparent obstruction 
 which, did it really exist, would effectually bar the way, 
 will disappear upon a careful inspection of the country, or 
 at the worst prove an insignificant obstacle compared to 
 those already passed. Obstacles to travel are not neces- 
 sarily obstacles to railway building. Narrow defiles, ob- 
 structed by boulders, underbrush, and timber will, when 
 cleared, appear comparatively smooth. 
 
 1400. Use of the Hand Level.— The hand-level is 
 of the greatest value, and should be in constant use. The 
 unaided eye is of little use in estimating comparative 
 elevations. The hand level determines relative heights, 
 constantly affording needed information and saving much 
 time, which, without it, would be spent in useless tramping. 
 
 1401. Keeping Notes. — A careful record should be 
 kept of all streams encountered; their direction, and of 
 what larger streams they are tributaries. 
 
 The sizes of different streams in the same section, to a 
 certain degree, determines their relative elevations. The 
 larger the stream the lower its elevation. The velocity of 
 its current, in a measure, indicates the grade of a stream, 
 though a fall which would make a torrent of a river Avould 
 give but a feeble current to a shallow stream. The recon- 
 
RAILROAD LOCATION. 817 
 
 naissance should cover a complete section of the proposed 
 line before the work of actual survey is commenced, though 
 it is not to be considered as complete until the final location 
 is fixed. 
 
 1402. Deceptive Appearances of Country. — The 
 
 natural eyesight is easily deceived, and rarely gives to 
 objects their true relative proportions.. Two reasons for 
 this deception are the following: 
 
 First, the eye foreshortens the distance in an air line, and 
 exaggerates a lateral offset. This fact is illustrated by 
 Fig. 355, in which let the points A a.ndB, which are 10,000 
 
 ft. apart, be in an air line between two towns, and suppose 
 this line to cross a ridge, the highest point of which is at C, 
 and that the ridge flattens out at D, 2,000 feet from C, the 
 middle point of A B. To the inexperienced, the offset C D, 
 as seen on the ground, will be greatly exaggerated, appear- 
 ing to be fully one-half the straight line A B, and the con- 
 viction will follow that in passing from A to B hy way of C, 
 not only will a great deal of curvature be introduced, but 
 the length of the line will be so greatly increased over that 
 of A B as to make a careful consideration of the route out 
 of the question; even though the line A Z>' should require 
 steep grades and a heavy cut at C. This exaggeration is 
 apparent when we find by calculation that the distance from 
 A to B hy way of D is only 770.33 ft. greater than the 
 direct line between A and B. This illusion of the eye ex- 
 plains the aversion to sivinging the line, too common among 
 engineers, and the undue importance attached to good 
 alineinent. The chances are four to one that the line 
 A D B is immensely superior to the line A B, both in cost 
 
818 
 
 RAILROAD LOCATION. 
 
 and grades, while the increase in distance of the line A D B 
 over the line A B vs, less than 8 per cent. 
 
 Frequently a deflection, which will not, in reality, add 
 more than 15 per cent, to the length of a line, will appear 
 to double it, and the deplorable mistake is often miade of 
 adopting the air line, even though it cost 25 per cent, in 
 excess of what the deflected line would cost. 
 
 Second, the eye exaggerates the sharpness of projecting 
 points and spurs and the degree of curvature necessary to 
 pass around them. All slopes when looked at from in front, 
 are exaggerated by the eye. Few mountains have slopes 
 exceeding 1^ to 1 or 33^°, yet the eye will estimate such a 
 slope at from 45° to 50°. 
 
 In running the line A B C D, Fig. 356, the engineer, if he 
 were to accept his natural estimate of the angles at B and C, 
 
 Fig. 356. 
 
 would make the angle at C about twice as large as the angle 
 at B; even though he had walked over the line. The reason 
 for this is that while standing at any point on the line B C, 
 his view of the line C D is cut off by the profile £ C of the 
 hill in front, and, in spite of himself, the unseen will be 
 distorted and invariably magnified. 
 
 Nowhere is the proverb, "appearances are deceiving," 
 so true as in an apparently smooth or gently rolling country. 
 The undulations are so gradual that their aggregate is rarely 
 suspected. Abundant experience goes to prove that an air 
 line in such a country is only possible at the cost of heavy 
 grades and long and heavy cuts and fills. To avoid them, 
 frequent deflections must be made, introducing curvature 
 in proportion, though the increase in length of line is in no 
 
RAILROAD LOCATION. 
 
 819 
 
 degree proportional to the saving in cost of construction and 
 operation. 
 
 1403. Discredit All Unfavorable Reports. — An 
 
 unfavorable report of a locality, more than any other, should 
 challenge a careful examination. The inexperienced are 
 easily daunted by obstacles which are really insignificant. 
 A section heavily timbered and covered with boulders, and 
 appearing to them as forbidding in the extreme, would likely 
 show an alinement and grades incomparably better than the 
 line of their choice. In reconnaissance it is the unexpected 
 which happens, and the line which appears least promising 
 will often prove, by far, the best. 
 
 1404. Choice of Lines. — Never believe that only one 
 line is possible. There are always two, and generally sev- 
 
 FIG. 357. 
 
 eral. The important question is, which line is the best, and 
 
820 RAILROAD LOCATION. 
 
 that is the one to settle upon. The following instance well 
 illustrates this point. The facts in the case are shown in 
 Fig. 357. The line had followed the river A B for several 
 miles, keeping a uniform grade of about 30 feet per mile. It 
 became necessary to leave the river valley and climb a ridge 
 in order to reach a town lying in another valley. The entire 
 country was thickly covered with timber and undergrowth, 
 and consisted of abrupt, irregular hills, called hog-backs. 
 The brook C was known to the engineer, who endeavored to 
 trace it to its junction with the river, but the brook lost it- 
 self in a cedar swamp at Z>, and it was impossible to find the 
 outlet. After repeated effort to find the outlet and encoun- 
 tering each time the ridge E which lay between the river and 
 the valley D C, he continued the line up the river, crossing 
 it at B, where a precipitous ledge prevented further progress 
 along the river, and crossing the neck of land /% and the 
 river at G, commenced to climb the ridge doubling about 
 the sharp headland at //, . and then swinging backwards, 
 making the line K L with a heavy fill at M. This seemed 
 the only possible line, but it was so rough and crooked that 
 the engineer determined to make another trial. He spent 
 two days in hard tramping during a continual downpour of 
 rain, discovering the narrow opening at N through which 
 the brook found its way. He also found the brooks /*and Q, 
 and blazed a line through from E \.o K. A line was then 
 run, following this course with the most satisfactory results, 
 saving two river bridges and three miles in distance, though 
 getting through the ridge at E entailed a heavy cut. The 
 railroad company was opposed to any further investigation 
 after the completion of the first line, as a month of hard 
 work had been expended upon it. Yet the saving in first 
 cost accomplished by the adoption of the second line over 
 the first would have paid the engineering expenses of the 
 entire line of 100 miles. In general, a better line than the 
 one already in hand can be found by looking for it. 
 
 1405. Advantages of Valley Lines. — Wherever 
 possible, stick to the valleys. Bottom lands, though low- 
 
RAILROAD LOCATION. 821 
 
 lying, are generally above flood line, or, if below it, are only 
 covered by back-water, else they would have been long since 
 washed away. Though a crooked channel may necessitate 
 frequent and sharp curves, yet they are more than compen- 
 sated for by the low grades fixed by that channel. As fre- 
 quently happens, the bends in the channel are caused by 
 projecting heads of hills. These sharp and often rocky 
 points usually require but short cuts, and furnish the best 
 of material for the adjacent embankments. 
 
 Notes should be kept of all important information gained. 
 Points where two promising lines diverge should be so 
 marked as to be readily recognized. 
 
 The reconnaissance being completed and all economical 
 and topographical questions settled, the next duty of the 
 engineer is the preliminary survey. The party should be 
 organized and all ready for service the moment the recon- 
 naissance and general route is decided upon. 
 
 1406. Organization of Party. — The size of the 
 party will depend upon the character of the country in which 
 the work is to be done. If thickly settled, smaller; if thinly 
 settled, larger. 
 
 A well-equipped party in ordinary country should number 
 sixteen men, as follows: The transit party, comprising 
 chief of party, transitman, two chainmen, three axmen, 
 one stakeman, and one back flagman; the level party, com- 
 prising the leveler, rodman, and one axman, and the topo- 
 graphical party, comprising the topographer and two assist- 
 ants. The last to be named, though not the last in point 
 of importance, is the teamster, who should be provided with 
 a strong, active team, and spring wagon that will not break 
 down. It is a most wasteful economy to require a party to 
 walk from two to five miles before commencing work, and 
 then to quit work in time to make another long tramp be- 
 fore reaching shelter. A chief of party who does not know 
 the necessity for a team and insist upon having it, is not fit 
 for the work in hand. No company will refuse to provide 
 it, if the matter be properly presented, yet many parties are 
 
822 RAILROAD LOCATION. 
 
 deprived of this important part of the outfit. If the party 
 are living in camp, a team is an absolute necessity for 
 moving the camp, which will be done at least once a week, 
 and usually once in three or four days. 
 
 1407. Caqip Outfit. — For camp work the following 
 outfit will be necessary: 
 
 Two wall tents with flies, or extra roofs, for the accom- 
 modation of the men, and, if the work is to be carried on 
 during the winter season, a tent must be provided for the 
 team ; a sheet-iron stove and provision chest for the com- 
 missary ; a cook who can prepare wholesome food and plenty 
 of it, and keep himself and belongings clean and orderly; a 
 drafting table, which is nothing more than a large draw- 
 ing board, a straight-edge and triangles, an ordinary pocket 
 case of drafting instruments, together with a beam com- 
 pass, will answer for all preliminary drafting. Drawing 
 and profile paper, note books, etc., are carried in a camp 
 chest. Each man provides his own bedding, which consists 
 of blankets alone. 
 
 The field instruments will comprise the following, viz. : 
 A surveyor's compass, plain transit, and transit poles, Y level 
 and Philadelphia leveling rod, aneroid barometer, clinom- 
 eter, slope rod, chain, axes, marking crayons, tacks, and 
 stake straps about the width and length of ordinary trunk 
 straps. A supply of stakes should be kept constantly on 
 hand. If possible, have these of light, well-seasoned wood 
 (pine is best) and of the following dimensions: Length 
 2 ft. 6 in., width 2 in., thickness ^ in., and planed on one 
 side so as to admit of easy and plain numbering. Special 
 conditions may require additional equipment, but the above 
 outfit will meet all ordinary requirements. 
 
 1408. The Compass for Preliminary Work. — If 
 
 the section be comparatively free from iron deposits, the 
 preliminary line should be run with the compass, for in spite 
 of small inaccuracies in alinement due to errors in reading 
 the needle, the average accuracy of a number of readings 
 will closely approximate to those read with the transit 
 
RAILROAD LOCATION. 823 
 
 vernier. The comparative advantages of compass and tran- 
 sit for preliminary railroad surveys was discussed in Art. 
 1217. Suffice to say, that where the conditions warrant 
 it, the compass is always the more economical and expedi- 
 tious instrument. If, however, iron exists in quantities 
 sufficient to hinder the perfect freedom of the magnetic 
 needle, the compass must be discarded for the transit, with 
 the injunction to never record an angle without first check- 
 ing it ; and after recording, read the angle a second time. 
 The assurance of accuracy is worth many times the labor 
 and care of checking work. 
 
 FIELD WORK. 
 1409. The Starting Point.— In general, the start- 
 ing point of the survey will be at an extremity of one of the 
 sections into which the proposed line is divided. If it is to 
 connect with some already existing line, a point on that line 
 is taken; if not, a street line or some other fixed boundary 
 is chosen and the line tied into it. The chief of party ac- 
 companied by a flagman, goes ahead and fixes the points 
 where the angles are to be taken. The flagman carries, be- 
 sides the transit pole, an ax for making plugs, one of 
 which he drives flush with the ground at every transit 
 point. A galvanized tack, or, better still, a small galvan- 
 ized nail, is driven in the center of the plug and the transit 
 pole (flag) held on the point while the transitman reads the 
 angle. A point having been fixed, and the flag set up, the 
 transitman measures the angle between the boundary at 
 Station and the first course. The angle and bearing of the 
 line being recorded, the transitman walks rapidly to the 
 point where the flag is standing and sets up the instrument 
 at that point. The head flagman should carry about a dozen 
 pieces of red flannel to be used as targets. As soon as a 
 transit point is set and the transitman has signaled that the 
 angle is read, the flagman should tie a piece of target flan- 
 nel to a light stake of about the same length as the transit 
 pole, and plant the pole firmly in line directly behind the 
 
824 RAILROAD LOCATION. 
 
 plug or transit point. This affords the chainman a good 
 target for liJiing in, and allows the flagman to join the chief 
 of party who has gone ahead to select another transit point. 
 The transit being set up, a backsight is taken to a flag held 
 at the starting point (Station 0). The bearing is then 
 checked and the angle turned to the next point ahead. The 
 chainmen having come up with the transit, they report the 
 number of the station of the transit point to the transitman, 
 who records it in the transit book. He then directs the 
 chainman on the next course, reads the forward angle and 
 records it together with the bearing of that course, and then 
 moves up to the next transit point. 
 
 1410. The Level Party. — The level party follows 
 the transit party as closely as possible. The levels of the 
 proposed line and the line with which it is to connect should 
 be referred to the same datum plane, so as to secure a con- 
 tinuous profile; especially if the levels of the established 
 line are referred to the sea level. If such a base is not 
 practicable, an elevation for the starting point must be as- 
 sumed, but of such a. height as will bring all elevations of 
 the proposed line above the assumed datum plane. 
 
 In case the country is wooded, with the added hindrance 
 of thick underbrush, the transit party will of necessity move 
 slowly, and the level party will consequently have much 
 spare time on their hands. They should provide themselves 
 with profile paper and keep the profile platted as the work 
 progresses. 
 
 1411. Bench Marks. — Bench marks are established 
 at intervals of from 1,000 to 1,500 feet, according as the line 
 is rough or smooth. At every stream which the line crosses 
 the elevation of the surface of the water and of the bed of 
 the stream should be taken. If there are any marks indica- 
 ting the elevation of high water, a rod reading should be 
 taken at such point and a record made of it. 
 
 141 2. The Topographical Party. — The topograph- 
 ical party follows the level party, though their rate of progress 
 will be more uncertain than either of the parties preceding 
 
RAILROAD LOCATION. 825 
 
 them. Where the slopes are uniform, they need not be 
 taken oftener than every third or fourth station. If, how- 
 ever, the country is broken and rough, it may be necessary 
 to take them .at each hundred feet, and with great 
 minuteness. 
 
 1413. Office Work. — At the conclusion of each day's 
 work, the field notes, both transit and level, are carefully 
 checked, and a plat of the line is made, either by tangents 
 or by latitudes and departures, carefully marking the cross- 
 ings of streams and highways, and noting any important 
 point which would enable the chief engineer to readily 
 locate any particular section of the line. Where the coun- 
 try is smooth the line may be platted to a scale of 400 feet 
 to the inch. Rough parts of the line may not exceed a 
 scale of 200 feet to the inch, and where difficult country is 
 encountered, involving detailed topographical maps, a scale 
 of 100 feet to the inch is advisable. Plat the line on sheets 
 24' X 30' in size, numbering them in regular order, each 
 sheet containing a part of the line on the immediately pre- 
 ceding sheet, so that by matching and pinning them 
 together, there may be had a continuous map of the line. 
 So arrange the line on the different sheets that when the 
 paper location is made they shall contain as many curve 
 centers as possible. 
 
 The topographer will do his proportional share of the 
 work, which will consist mainly in a detailed explanation of 
 the notes of the day's work to the draftsman, whose princi- 
 pal work is the contour maps. The leveler will plat the 
 day's levels on the continuous profile kept in the office, the 
 rodman reading the notes. This profile will contain as full 
 information as possible, especially relating to highways and 
 watercourses. 
 
 Some engineers prefer to wait for a rainy day in which to 
 do the office work, but more make it an invariable rule to 
 plat each night the work of the day. This practice enables 
 the chief of party to have a complete record of his work 
 always ready for the inspection of the chief engineer, who 
 
626 
 
 RAILROAD LOCATION. 
 
 is liable to appear at any time. If he is his own chiefs per- 
 sonal interest in the work would warrant him in making 
 such a rule. Notes which are platted when/V^.f// are always 
 of more value than when stale, and the daily office work 
 unites the different parties which are separated during the 
 day, sustaining a common interest in the work. If the con- 
 tour maps are to keep pace with the survey, the draftsman 
 must be an expert. Each day he plats the work of the pre- 
 ceding day, and under the direction of the topographer, 
 every point is covered. 
 
 1414. Spur Lines. — At certain points of the main 
 line, two and sometimes three different routes will present 
 
 Fig. 368. 
 
RAILROAD LOCATION. 827 
 
 themselves for reaching another point of that line, and re- 
 quire the running of spur lines to determine the most advan- 
 tageous route. The main line being run, the spur lines are 
 tied into it, designating them by different letters, as liney^, 
 line B^ etc. The comparative advantage of the different 
 alinements will show themselves in the plat. Their com- 
 parative profiles are commonly shown by platting them in 
 different colors. A case requiring spur lines is shown in 
 Fig. 358. Here the general direction of the main line is 
 C D E F, D being the point where the spur lines A and B 
 diverge from the main line, and E where they again unite. 
 It will be evident from an inspection of the map that 
 the main line is superior to both the spur lines in point 
 of alinement. Their comparative lengths are already 
 known. With the comparative profiles before the engineer, 
 he, knowing the nature of the ground on the different lines, 
 will have no difficulty in making a judicious choice of lines. 
 Sometimes where the merits of the different lines are nicely 
 balanced, it becomes necessary to locate on two lines and 
 base a decision upon actual estimate of cost of construction. 
 
 1415. Gradients. — The preliminary survey having 
 been completed, a careful study of the profiles will enable 
 the chief engineer to establish a gradient whose maximum 
 will limit the train loads passing over it. 
 
 The character of the expected traffic will greatly modify 
 this maximum. If the road is to do a passenger business 
 principally, the gradient may be raised, but if the bulk of 
 the business is to be freight, the gradient must bcplaced at 
 the lowest possible limit which the finances of the company 
 and the nature of the country will permit. 
 
 Should all the heavy grades occur on a short section of the 
 line, it may be policy to mass them within the smallest pos- 
 sible limits and proportionately reduce the gradient of the 
 remainder of the line. In such an arrangement of grades, 
 an assistant engine would be used on the summit section, 
 and so cover the entire line without any change of train 
 loads. 
 
828 
 
 RAILROAD LOCATION. 
 
 1416. Curvature. — There is no absolute rule for 
 limiting curvature. The approximate limit will depend 
 upon the topography of the country and upon the character 
 of the expected traffic, a freight traffic admitting a higher 
 and a passenger traffic requiring a lower degree of curvature. 
 For all ordinary traffic conditions, i. e., where freight and 
 passenger traffic will be about equal, the invariable rule is 
 use such curves as zvill best conform to the existing 
 topographical conditions. 
 
 Any curve up to 10 degrees will be no obstacle to a speed 
 of 30 miles per hour, the average speed of passenger trains. 
 This affords a range in curvature which will meet the 
 requirements of most localities. 
 
 Curvature is no blemish to a line, if it secures the great 
 advantages of low gradients and moderate cost. At points 
 
 Fig. 359. 
 
 where moderate curves are possible only at great cost, it is 
 often a wise policy to build a temporary line, using sharp 
 curves, and put off the expensive work until the financial 
 strength of the company warrants its undertaking. 
 
RAILROAD LOCATION. 8'29 
 
 An instance where a temporary line is expedient is shown 
 in Fig. 359. Here the track follows the windings of a stream 
 in a narrow valley, whose sides are steep and rough. Unless 
 the company is financially strong, it will be much better 
 policy to build the line A B C D £, using curves as high as 
 15°, and reducing cost to a minimum, than to build the line 
 A F B, giving a single curve of G°, but requiring a heavy 
 rock cut at /% or perhaps a tunnel at that point. The line 
 A F £ is always possible, and when the road has built up a 
 paying traffic and finances are easy, the cut or tunnel at F 
 can be made without interfering in any way with traffic, and, 
 in all probability, at much better prices than when the. 
 temporary line was built. 
 
 The question of gradients being decided, a preliminary 
 profile is made, which will serve as a basis for a paper 
 location. 
 
 1417. A Paper Location. — The paper location is 
 substantially the one which takes permanent form in the 
 final or located line. It is laid down on the contour maps, 
 which contain all the information accumulated by the pre- 
 ceding surveys. The grade for each station is taken from 
 the preliminary profile and marked on the contour maps 
 opposite the corresponding station. This is readily done, as 
 the contours are but five feet apart, and intermediate eleva- 
 tions can easily be estimated. These grade points are com- 
 monly marked by small red dots enclosed in small circles of 
 the same color, and show where the plane of the grade 
 would cut the surface of the ground. A piece of fine thread 
 is then stretched, covering as many of these points as pos- 
 sible, and a pencil line drawn in place of the thread. This 
 pencil line will locate a tangent on the map. In the same 
 way any number of tangents may be located. 
 
 A set of office curves will be of great assistance in fitting 
 curves to the tangents, the curves like the tangents fol- 
 lowing the grade line as nearly as possible. Having 
 determined the degrees of curve uniting the tangents, the 
 intersection angles are calculated by tangents and the 
 
830 
 
 RAILROAD LOCATION. 
 
 Fig. 360. 
 
 tangent distances accu- 
 rately scaled from the 
 intersection points. 
 
 1418. Field Notes 
 from the Paper Lo- 
 cation. — In taking notes 
 from the paper location 
 for actual field work, the 
 points of curve and points 
 of tangent should be care- 
 fully referred to fixed 
 points in the preliminary 
 line (either stakes or 
 plugs, the latter are pref- 
 erable) so that if, upon 
 the completion of any 
 curve, the following tan- 
 gent does not take the 
 position prescribed for it 
 in the notes, it may be 
 stvnng into that position. 
 It is impossible, especial- 
 ly in a rough country, to 
 make the actual measure- 
 ments agree with the cal- 
 culated measurements, 
 hence small inaccuracies 
 need cause no concern. 
 
 The platting of a paper 
 location is illustrated in 
 Fig. 300. Here the grade 
 of the line is determined 
 by the grade of the stream, 
 which it closely follows. 
 The grade averages . 5 per 
 cent. The preliminary 
 line is shown dotted, and 
 
RAILROAD LOCATION. 831 
 
 the located line is drawn full. Let the grade for Sta. 1 be 11.0 
 feet. The grade for Sta. 2 will, therefore, be 11.0 feet plus. 5 
 foot, or 11.5 feet. The grade for Sta. 3 will be 11. 5 + .5, 
 or 12 feet. By the same process we find the grade for each 
 of the stations given in the plat. The grade for each station 
 is then marked on the contour map opposite the correspond- 
 ing station of the preliminary line by a small dot enclosed 
 in a circle. Straight lines A B and C D, which are to form 
 tangents in the paper location, are then drawn, covering as 
 many of these small circles as may be, and produce, until 
 they intersect at E. The line ^ ^ is then produced to F, 
 making E F = 300 feet or any other convenient length of 
 radius suitable for measuring the intersection angle by its 
 tangent. At /^ erect the perpendicular F G, which will 
 be the tangent of the intersection angle F E G. Meas- 
 uring F G hy scale F G = 140 feet, though by calculation 
 139.89 feet. Dividing 140 by 300 we have a quotient of 
 .4667 = tan 25°. We find By trying different curves that 
 an 8° curve will most nearly cover the grade points between 
 the tangents A B and C D. From formula 9 1 , 7" = /? tan \ I 
 (Art. 1251), we find the tangent distance = 158. 9 feet. 
 Scaling from the intersection point E on both tangents this 
 distance we locate the P. C. and P. T. The station of the 
 P. C. we determine by scaling from the P. T. of the last 
 curve. The station of the P. T. is, of course, found by, 
 calculation. 
 
 1419. Paper Location Profile. — A profile, called a 
 paper location proflle, is made from elevations taken 
 from the contour map at each station of the paper location, 
 and a grade line drawn on it which should be substantially 
 that of the final location, and if the preliminary work has 
 been thoroughly done, the discrepancy will be but slight. 
 
 1420. Actual Location. — The location party has the 
 same organization as the preliminary party, excepting the 
 topographer and his assistants. Their work is supposed to 
 be completed. The chief of party carries, besides the notes 
 of the location, which is to be run in on the ground^ the map 
 
832 RAILROAD LOCATION. 
 
 covering the section immediately in hand, as not infre- 
 quently it is necessary to slightly modify the paper location. 
 He will need in addition a short scale and compass carrying 
 a pencil point. 
 
 Where the country is open, it is good practice to locate 
 the tangents by offsets from the preliminary line and make 
 the intersections on the ground ; but if the ground is covered 
 with brush or timber, the paper location must be strictly 
 followed, and the results will generally fulfil all reasonable 
 expectations. 
 
 PROBLEMS IN LOCATION. 
 
 1421. Problems in Location. — The tangents being 
 fixed in the paper location, the purpose is to so fix the point 
 of curve, the P. C, that, the curve being run, its tangent 
 shall coincide with the following tangent as laid down in the 
 paper location. Frequently, the actual tangent fails to 
 coincide with the theoretical tangent, in which case it must 
 be swung- into place. Sometimes the tangents not only fail 
 to coincide, but form an angle with each other, in which 
 case the central angle of the curve must be either increased 
 or diminished, as the case demands. These modifications 
 of the paper location give rise to the following problems, 
 which will cover all ordinary cases: 
 
 1422. Problem I. — To change the P. C. of a curve so 
 that the curve shall terminate in a tangent parallel to a 
 given tangent and at a given distance from it: 
 
 Let A />', Fig. 3G1, be a curve terminating in the tangent 
 B C, and it is required to change the P. C. of the curve 
 from A to A' , so that it shall terminate in a tangent B' C 
 parallel to B C and at a fixed distance from it. 
 
 The angle B B' D = I, the angle of intersection of the 
 tangents. 
 
 We have sin B B' D = -rm, whence B B' = —. — ,. 
 B B sm / 
 
 B B' ■= O O' = A A\ the required distance to move the 
 P. C. of the curve either backwards or forwards, according 
 
RAILROAD LOCATION. 
 
 833 
 
 as the required tangent is within or without the given 
 tangent. 
 
 Substituting A A' ior B B' we have A A' = -. — j. 
 
 In the figure the required tangent is within the given 
 
 Fig. 361. 
 
 tangent. Let the intersection angle be 68° and the distance 
 
 40 
 B D = iO feet. Sin G8° = .92718, whence A A' = —z^^ = 
 
 43.14 feet. 
 
 That is, the P. C. of the required curve must be moved 
 
 backwards 43.14 feet from the P. C. of the given curve. 
 • 
 
 1 423. Problem II. — To change the point of compound 
 curvature, the P. C. C, so that the second curve shall ter- 
 minate in a tangent parallel to a given tangent, and at a 
 given distance from it. 
 
 Case I. When the second curve is of shorter radius than 
 the first curve: 
 
 Let A B D, Fig. 362, be a compound curve terminating 
 
834 
 
 RAILROAD LOCATION. 
 
 in the tangent D H, and let it be required to change the 
 
 P. C. C. from B to some 
 point E, so that the curve 
 shall terminate (as shown in 
 the figure) in a tangent F G, 
 parallel to and at a given 
 distance H G from D H. To 
 determine the point E (the 
 new P. C. C. ) the angle ELF 
 must be determined, and sub- 
 stituted for the known angle 
 B K D. From C, the center 
 of the larger curve, let fall 
 upon F G the perpendicular 
 C G. From K and L let fall upon C G the perpendiculars K M 
 and L N. Call the longer radius C B,R\ the shorter radius 
 K D, r; the distance I F or its equal H G, D; the angle 
 B K D ox its equal K C M,x, and the required angle ELF 
 or its equal L C N, y. Then, 
 
 MN 
 
 Fig. 362. 
 
 {R — r) COS x-\- D 
 cos y = ^ ^_^ ^ • 
 
 (99.) 
 
 That is, //le distance I F or H G measured rectangularly 
 between the two tangents, being added to the difference of the 
 radii times cos x, and the result divided by the difference of 
 the radii, tvill give the cosine of the angle ELF, or y, to be 
 turned on the smaller curve. 
 
 Subtracting the angle j' from the angle.!', will give the 
 angle B C E, to be added to the larger curve; and dividing 
 this angle by the degree of curvature in ^ .5 we find the 
 distance from B to E, the required P. C. C. 
 
 \i E F h^ the second curve located, and the required 
 tangent lies within, i. e., D H '\s the required tangent, it is 
 evident that instead of advancing on the curve A B, we must 
 retreat on it to find the required P. C. C. Accordingly, 
 we subtract D instead of adding, as in the preceding case. 
 
 Example. — A B, Fig. 362, is a 4° curve to the right, located and 
 compounding at B into a 7'" curve, the latter being continued through 
 an angle of 38°. At the P. T. we find that the proper tangent is 46 ft. 
 
RAILROAD LOCATION. 835 
 
 to the left, i.e., without the actual tangent, so that the curve will be 
 thrown out to meet the required tangent. How far must the 4° ciirve 
 be continued? 
 
 Solution. — The radius of a 4° curve is 1,432.69 ft. ; the radius of a 
 7= curve is 819.02 ft., hence, R - r= 613.67 ft. The cosine of 38° = 
 .78801. Substituting known quantities in formula 99, 
 
 (/? - r) cos X 4- Z? 613. 67 X . 78801 + 46 ^ _„. . 
 
 ^^^■^ = -R^r = 613:67 = '^^^^^ 
 
 Hence, angle y — 30° 21'. Subtracting this angle from 38" 00', there 
 remains a difference of 7° 39', which must be added to the 4° curve. 
 7° 39' reduced to decimal form is 7.65' -e- 4 gives 1.9125 stations = 
 191.25 feet, which must be added to the 4" curve to reach the correct 
 P. C. C. Ans. 
 
 In the above example, it is evident that, had the required 
 tangent been within the given tangent, it would have been 
 necessary to move the P. C. C. backwards instead of advan- 
 cing it. This will increase the angle y of the second curve, 
 and, consequently, its cosine will be reduced. The distance 
 D will, therefore, be subtracted and the formula will read^ 
 
 {R — r) cos X — D 
 Q,o^yr=- '^ — . (lOO.) 
 
 K — r 
 
 1424. Problem II. — Case II. When the second curve 
 is of longer radius than the first curve: 
 
 Let A B F,in Fig. 363, be a compound curve terminating 
 in the tangent FH, and it is required to change the P. C. C. 
 from B to some point £ so that the curve shall terminate in 
 the tangent D G parallel to F H and at a given distance 
 H G from it. 
 
 Let the required tangent D G ho. without the given 
 tangent F H. Calling the perpendicular distance H G 
 between the tangents D\ the radius of the larger curve, /?, 
 and the radius of the smaller curve, r; the given angle 
 B O F oi the second curve, ,r, and the required angle E C G 
 of the second curve j, we have, as in formula lOO, 
 
 _ (/? — r) cos X — D 
 
 cos J 
 
 R-r 
 
 That is, the distance // 6^, measured rectangularly between 
 the two tangents, should be subtracted as in formula lOO. 
 
836 
 
 RAILROAD LOCATION. 
 
 It will be seen that the required tangent is without the 
 given tangent, consequently, it will be necessary to move 
 
 E 
 
 Fig. 363. 
 
 the P. C. C. backwards on the first curve, i. e., the angle of 
 the first curve must be reduced. 
 
 Example. — A ^ is a 6° curve compounding at B into a 3' curve 
 whose angle is 42° 30', and whose tangent F H is 52 ft. within the 
 required tangent. How far backwards must the P. C. C. be moved ? 
 
 Solution. — The radius of a 6° curve is 955.37 ft., and the radius of 
 
 a 3° curve is 1,910.08 ft.; hence, /?- r = 1,910.08 - 955.37 = 954.71. 
 
 Cos x= cos 42° 30' = .73728. Substituting the known values in formula 
 
 ^„„ , 954.71 X. 73728 -52 ._„. . _ , 
 
 lOO, we have cos y ~ -., „^ = .68281 ; whence, we find 
 
 •^ 9o4.71 
 
 y = 46° 56'. Deducting 42° 30' from 46° 56', we have a diflference of 
 
 4° 26', which must be deducted from the first curve. 4° 26' in decimal 
 
 form is 4.433; 4.433 -¥■ 6, the degree of the first curve, gives a quotient 
 
 of .739 of a full station = 73.9 ft., the distance backwards from B to the 
 
 correct P. C. C. at E. Ans. 
 
 If the required tangent were within the given tangent, 
 the P. C. C. would be advanced and the angle y would be 
 
RAILROAD LOCATION. 
 
 837 
 
 reduced. The distance D would then be added and the 
 formula would read 
 
 cos J 
 
 
 1425. Problem III. — To avoid obstacles on a curve : 
 Let it be required to run a curve A DEC between the 
 points A and C, and suppose an obstacle lies directly in the 
 path of the curve. The obstacle may be avoided by tracing 
 a parallel curve FG HI, and from the stations on this par- 
 allel curve, the corresponding stations on the required 
 
 Fig. 3&4. 
 
 curve may be located. The process is as follows (see 
 Fig. 364): 
 
 Having determined either P. C. or P. T., erect a per- 
 pendicular A F to the tangent A K. Now, io the curve 
 FGH I it is evident that while the angle AO C remains 
 constant, the chords F G, G H, and HI shorten as we 
 approach the center of the required curve. L,etAF = 
 
838 RAILROAD LOCATION. 
 
 90 ft., and the radius A (9 = 819 ft. The chords of the 
 required curve being 100 ft. in length, we have the follow- 
 ing proportion : O A : O A — A F::100 : F G, Xhe^ length of 
 the chord of the parallel curve. 
 
 Substituting known values in the proportion, we have 
 819 : 729:: 100 : FG; whence, /^ 6' = 89.01ft. Set up the in- 
 strument at Fand trace the curve F G H I, setting a transit 
 point at each station of 89.01 ft. Then set the transit at 
 each of these points, as at 6", and turn to a tangent of the 
 curve as run. Then, turning a right angle, set a stake 90 
 ft. from G, locating the point D. In a similar manner 
 locate each of the stations upon the required curve. 
 
 1426. Problem IV. — Having given two angles of 
 intersection Z? -5 E and G F H, and the distance ^/'between 
 the points of intersection (Fig. 365), it is required to find 
 the radius of the easiest reverse curve which will unite 
 
 Fig. 365. 
 
 the tangents A D and FK. The angle D B E \s equal to 
 the angle A O E, half of which is B O E. The angle G FN 
 is equal to the angle J5" CG, half of which is EC F. Then, 
 (tan B O E -\- X.z.n E C F) \\.2.n BO E\\ BE : BE. But 
 E F — BE— BE. Reducing the proportion, we have 
 
 _ tan BO Ex BE 
 tan B O E -\- tan ECF' 
 
 Now, BE is the tangent distance 7^ of the curve A E, and 
 
RAILROAD LOCATION. 839 
 
 substituting known values in formula 91, T=R tan |/ 
 (Art. 1251), v^e have B £= O £ tsin B O £; whence, 
 
 B£ EF 
 
 radius O E =z and radius C E = 
 
 tan B O E' ^<^^^^^ ^ ^ - ^^^ ^f-p- 
 
 Example.— Let the angle D B E, Fig. 365, = 40° 00', the angle 
 G F H=m° W, and the distance i? 7^= 922 ft. Find the radius of 
 the reverse curve. 
 
 Solution.— The angle BOE=\DBE = 20°, and the angle ECF= 
 
 iGFH= 31° 15'. Tan 20° = .36397; tan 31° 15' = .60681. The sum of 
 
 these tangents is .97078, and we have the proportion .97078 : .36397:: 
 
 922 : B E\ whence, we find ^ £"= 345.68 ft. Substituting the value 
 
 oi BE in the formula, T = B tan i /, we have 345.68 = OEx -36397 ; 
 
 345 68 
 whence, we have radius 0E= ,^"^-, =949.75 ft. Substituting this 
 
 . ooo9 I 
 
 50 
 value of ^ in the formula, B = -. — = (Art. 1249), we have sin D = 
 
 sin D ' 
 
 50 
 x-T7r-=rr, whcncc, sin D = .05264 and Z> = 3° 01', which, multiplied by 2, 
 949. 75 
 
 gives 6° 02', the required degree of the curve A E. To show the 
 
 student that the curve EG is of the same degree as the curve A E, 
 
 we complete the calculation as follows : B F= 922 ft. and E F = 922 — 
 
 345.6» = 576.32 ft. Substituting the value oi EF'in the formula T = 
 
 576 S'> 
 R tan \ I, we have radius CE= Z'JZ = 949.75 ft. Ans. 
 " .60681 
 
 50 
 Substituting this value of R in the formula, R = —. — ^, we have 
 
 50 
 sin D = „,_ ... , whence sin D = .05264, and Z> = 3° 01' ; this, multiplied 
 949. 7o > r 
 
 by 2, gives 6° 02', the required degree of the curve EG, which is the 
 
 same as that of the curve A E. Ans. 
 
 1427. Problem V. — To find the radius of a curve 
 which will be tangent to three given straight lines: Let 
 A B, B C, and C D, in Fig. 366, be the given lines, then the 
 required radius will be equal to 
 
 BC^ 
 
 tan \ E B C + tan \ E C B' 
 
 Example.— Let ^C = 428 feet, the angle ^^^ C= 23" 20, and the 
 angle EC B = 'i>^° 20'. Find the radius of the curve that will be tan- 
 gent Xo A B, B C, and CD. 
 
 Solution.— Tan i EBC=. 20648, and tan i i5"Cy? = .22475. The 
 sum of these tangents is .43123. Substituting these values in the 
 
840 RAILROAD LOCATION. 
 
 equation, radius = — „ _ ^^ . ^^ „ , we have radius = 
 
 tan i £B C + tan ^ ECB' .43123' 
 
 whence the required radius = 992.51 ft. Substituting this value of Ji 
 
 50 
 in formula 89, Art. 1249, we have sin Z> = p^-^ = .05038, and 
 
 Z> = 2° 53.3', which, multiplied by 2, gives 5° 46.6', the required degree 
 
 of the curve. Ans. The required degree of curve may be found by 
 the following and simpler operation, viz.: Dividing 5,730 ft., the 
 approximate radius of a 1° curve, by the given radius, 992.51 ft., we 
 obtain a quotient of 5.773° = 5° 46.38', a result amply close for practical 
 work. The angle of intersection C£Fis equal to EBC+ECB = 
 48° 40'. Having found the radius and angle of intersection, the tan- 
 gent distance is calculated by formula 91, T= R tan | /. (See Art. 
 1251.) 
 
 1428. Problem VI. — To swing a tangent so that it 
 will pass through a given point: 
 
 Let A B^ in Fig. 367, be a curve whose tangent .5 ^ passes 
 through the point C, and it is required to swing the tangent 
 B X into the position B' X\ so that it shall pass through 
 the point C . With the instrument at B measure the angle 
 C B C. Divide this angle by the degree of the curve A B. 
 The quotient will be the distance, in stations, which must be 
 added to the curve A B to bring the P. T. at B\ and the 
 tangent will pass through the required point C. 
 
 Example. — Let A B he a. 6° curve, and the angle C B C = 4" 30'. 
 
 Swing the tangent .5 C so as to pass through the point C 
 
 Solution. — Reducing 4° 30' to decimal form and dividing by 6, the 
 
 4 5 
 degree of the curve A B, we have-^ = .75 of a full station = 75 ft., 
 
 which we must add to the curve A B, bringing the P. T. at B', and the 
 tangent B' X' will pass through the point C. Ans. 
 
 It will be evident that, had B' X' been the given tangent 
 and C the required point, it would have been necessary to 
 
RAILROAD LOCATION. 
 
 841 
 
 move the point of tangent B' backwards to B, i. e., to 
 subtract 75 ft. from the given curve. 
 
 3130 
 
 1 429. Problem VII. — To find the distance across a 
 river in a preliminary survey: 
 
 Let the line A B, Fig. 368, 
 cross a river, too wide for 
 direct measurement. With 
 the instrument at A^ sight 
 to a flag held at B, and turn 
 a.n 2ing\e B A C = \° . Seta 
 plug at C, opposite B in the 
 line A C, and measure the 
 distance B C. 
 
 The required distance 
 ^ C" X 100 
 
 ^^= 1.745 
 Example 1.— If BC- 
 
 Fig. 368. 
 10.6 ft., how long is A B7 
 
 Solution.— y? B = ^^f^)^^ = 607. 45 ft. Ans. 
 1.745 
 
842 
 
 RAILROAD LOCATION. 
 
 Example 2.— If /)'t" = 8.8 ft., how long is A B? 
 8.8 X 100 
 
 Solution. — A B ■ 
 
 1.745 
 
 = 504.3 ft. Ans. 
 
 1430. Engineers' Field Books. — The problems 
 given cover the cases which are liable to arise under ordi- 
 nary conditions, and the explanations have been fully given. 
 The engineer must necessarily carry a field book containing 
 the usual tables of reference. All standard field books con- 
 tain demonstrations of problems covering all those special 
 cases which do not properly come within the scope of this 
 work. 
 
 1431. Relative Position of Preliminary and 
 Located Line. — The relative position of the preliminary 
 and of the located line, 
 where the work has 
 been intelligently per- 
 formed, is shown in the 
 following sketch, Fig. 
 369, in which the pre- 
 liminary line is shown V' The location is 
 in dotted and the loca- ^^ practically fixed 
 tion in full lines. fV X \ \ by the preliminary 
 
 line, leaving little 
 to do but to run in 
 the curves. The 
 slight changes in the 
 direction of the tan- 
 gents and the degrees of the curves 
 will be determined by an inspection of 
 the contour map, which is the basis of 
 every intelligent location. 
 
 1432. Field Profiles.— The profile is kept plat- 
 ted as fast as the line is located, in order that the chief 
 of party may know how nearly the actual profile ap- 
 proximates to the theoretical one (the one that is made 
 from the paper location) and what changes may be 
 necessary. 
 
 Fig. 3C9. 
 
RAILROAD LOCATION. 
 
 843 
 
 1433. Final Location. — After the right of way has 
 been cleared, affording an unobstructed view of the ground, 
 it will frequently be seen that slight changes in the located 
 line will greatly reduce the cost of construction ; and not 
 until such changes are made will the engineer have made 
 the fitial location. 
 
 None but experienced engineers can understand how a 
 
 Area^4.5 Sq.ft. 
 
 Fill 30ft 
 
 T 
 
 Fig. 370. 
 
 slight change in location, especially on a side hill line, can 
 so greatly affect cost; and it is first cost which generally de- 
 termines the success or failure of the enterprise. 
 
 The accompanying sketches will afford some light where it 
 is oftenest needed. Fig. 370 is an example of poor location 
 more often met with than that of any other kind, and yet 
 one where a little conscientious work, together with common 
 
 nil 5.8ft 
 
 Fig. 371. 
 
 sense, would have produced amazing results, as shown in Fig. 
 371, which is decidedly good location. Side hills afford op- 
 portunity for almost the cheapest form of construction. A 
 
844 RAILROAD LOCATION. 
 
 grade line, i. e. , where the grade coincides with the surface 
 of the ground on the center line, as in Fig. 371, can, unless 
 rock is encountered, be graded with pick and shovel alone, 
 the men casting the material taken from the cut directly 
 into and making the fill. The area of the cut in Fig. 370 is 
 49.8 sq. ft., while the area of the fill is but 4.5 sq. ft., leaving 
 an excess of excavation of 45.3 sq. ft., or ten times the area 
 of the fill. There is no way by which this excess of mate- 
 rial can be utilized ; it must, therefore, be wasted, as has 
 been the labor of excavating it. By moving the center line 
 4 feet to the right, we obtain the cross-section shown in Fig. 
 371, in which the calculated areas of cut and fill are as fol- 
 lows: Cut, 19.2 sq. ft. ; fill, 20.3 sq. ft. ; a difference of less 
 than 1 sq. ft., and the excess is on the right side, for a ditch 
 should be made four feet from the top of the upper slope to 
 prevent the washing down of the slope, and this material 
 will more than equal the excess of the fill over the cut. 
 
 1434. Referencing Transit Points. — Having com- 
 pleted the final location, the points of curve and points of 
 tangent must be referenced, and also intermediate points 
 where a change of grade requires it. Such an intermediate 
 point is shown in Fig. 372. 
 
 Fig 372. 
 
 The line ABC from the P. T. at A to the P. C. at C is 
 straight, but the transit pole at C can not be seen through 
 the transit SitA on account of the change of grade at B. It 
 is, therefore, necessary to establish an intermediate point at 
 B on the line ABC. The transit being set up at B, both 
 P. T. and P. C. are in full view. 
 
 A good example of referencing is shown in Fig. 373. The 
 reference points consist of plugs driven flush with the 
 ground and protected by substantial guard stakes, which are 
 
RAILROAD LOCATION. 
 
 845 
 
 marked with the letters JR. P. Where the located line trav- 
 erses timber or brushwood, the ordinary stakes on the 
 center line should be replaced by much larger ones. They 
 are best cut from saplings about 3 feet in length and from 
 2^ to 3^ inches in diameter. A place for the stake is made 
 with an iron bar, and the stake driven at least one foot in 
 the ground with a sledge hammer. Special care is taken in 
 
 *lug and 
 Guard Stake 
 
 Plug and 
 Guard Stake 
 
 £C 
 
 Fig. 373. 
 
 guarding points of curve and tangent. While the right of 
 way is being cleared a man is detailed to look after the 
 stakes and hubs on the center line, as many will be disturbed 
 or torn out of the ground while hauling logs and timber 
 from the right of way. When the clearing and burning is 
 completed, the center line should be rerun, restoring all 
 lost or disturbed stakes. Transit points, if well set, will 
 rarely be disturbed. When the center line is restored the 
 transit points are referenced. A little care and judgment 
 will enable the engineer to select reference points which will 
 remain undisturbed during the work of construction. 
 Where the work is heavy these points will be further re- 
 moved from the center line than at points where the work 
 is light. 
 
 When the grading is completed, the original points of 
 curve and tangent can be restored and the center line run 
 in from both ends of the curve. Any small error in aline- 
 ment due to inaccuracies in the measurement of the original 
 line will then be thrown on the middle of the curve, where 
 
846 RAILROAD LOCATION. 
 
 they will not in any way affect the excellence of the work, 
 and the tangents will remain unchanged. 
 
 1435. Final Levels. —While the transit points are 
 being referenced, the leveler takes the final levels^ reading 
 all turning points with the target and correcting all bencli 
 marks. He need not hurry, as accuracy is all important. 
 An error in final levels is unpardonable, as the work of con- 
 struction is based upon them. Most errors in field work are 
 directly chargeable to carelessness. A bench mark is estab- 
 lished at each bridge site, and at all points of the line where 
 permanent structures, such as arch culverts, trestles, water 
 tanks, stations, etc., are to be built. The final profile is 
 platted from these levels and the grade line drawn in pencil. 
 The points of curve and tangent are marked in small cir- 
 cles on one of the horizontal lines at the bottom of the pro- 
 file. That portion of the line corresponding to tangents is 
 drawn in a full line, and the balance, representing the 
 curves, in broken line. The stations of the points of curve 
 and tangent are also numbered on the profile. 
 
 The compensations for curvature are then calculated, and 
 the final grade line drawn in ink. 
 
 1436. Compensation for Curvature. — From .03 
 
 to .05 ft. per degree is the compensation or reduction in 
 grade, made for the added resistance due to curvature, i. e. , 
 where the established grade for tangents is 1 per cent., the 
 grade on a 6° curve, allowing a compensation of .03 ft. per 
 degree, would be LOO— (.03 ft. x 6) — .82 per cent. Where 
 a compensation of .05 ft. per degree is made, the grade on 
 a G° curve would be 1.00 — (.05 X n) = .70 per cent. 
 
 1437. Final Grade Lines. — The establishing oi final 
 grade lines is illustrated in Fig. 374, where the uncompen- 
 sated grade is 1.3 per cent., and the compensation for 
 curvature as shown in the final grade line is .03 ft. per 
 degree. 
 
 The location notes for the line included in the diagram are 
 
 as follows: 
 
 I* 
 
RAILROAD LOCATION. 
 
 847 
 
 Stations. 
 
 Intersection Angles. 
 
 52 + 00 
 
 End of Grade. 
 
 49 + 75 P. T. 
 
 
 44 + 25 P. C. 9° R. 
 
 49° 30' 
 
 ~ 42 + 00 P. T. 
 
 
 37 + 50 P. C. 6° L. 
 
 27° 00' 
 
 33 + 00 P. T. 
 
 
 29 + 00 P. C. 8° R. 
 
 32° 00' 
 
 27 + 00 
 
 Beginning of Grade. 
 
 The profile is made to standard scales, viz., horizontal 
 400 ft. = 1 in. ; vertical, 20 ft. = 1 in. The elevation of the 
 grade at Sta. 27 is fixed at 120 ft., and at Sta. 52 at 152.5 ft., 
 giving between these stations an actual rise of 32.5 ft. and 
 an uncompensated grade of 1.3 per cent. These grade points 
 we mark on the profile in small circles. The total curvature 
 between Sta. 27 and Sta. 52 is 108^°. The resistance due to 
 each degree of curvature being taken as equivalent to an in- 
 crease of .03 ft. in grade, the total resistance due to 108. 5° is 
 equal to .03 ft. X 108.5 = 3.255 ft., and is equivalent to 
 adding 3.255 ft. to the actual rise between Sta. 27 and Sta. 52. 
 Hence, the total theoretical grade between these stations is 
 the sum of 32.5 ft., the actual rise, and 3.255 ft. due to 
 curvature, which is 35.755 ft. Dividing 35.755 by 25, the 
 
 35 755 
 number of stations in the given distance, we have^ — ^-- — = 
 
 25 
 
 + 1.4302 ft., the grade for tangents on this line. The starting 
 
 point of this grade is at Sta. 27. The P. C. of the first curve 
 
 is at Sta. 29, giving a tangent of 200 ft. = 2 stations. As 
 
 the grade for tangents is + 1.4302 ft. per station, the rise in 
 
 grade between Stas. 27 and 29 is 1.4302X2 = 2.8604 ft. 
 
 The elevation of the grade at Sta. 27 is 120 ft., and the 
 
 elevation of grade at Sta. 29 is 120 + 2.8604 = 122.8604 ft., 
 
 which we record on the profile as shown in Fig. 374, with the 
 
848 RAILROAD LOCATION. 
 
 rate of grade, viz., -j- 1.4302 written above the grade line. 
 The first curve is 8°, and as the compensation per degree is 
 .03 ft. for 8°, or a full station, the compensation is .03 ft. X 
 8 = .24 ft. The grade on the curve will, therefore, be the 
 tangent grade minus the compensation, or 1.4302 — .24 ft. = 
 + 1.1902 ft. per station. The P. C. of this curve is at 
 Sta. 29, the P. T. at Sta. 33, making the total length of the 
 curve 400 ft. = 4 stations. The grade on this curve is -|- 
 1.1902 ft. per station, and the total rise on the curve is 
 1.1902 X 4 = 4.7608 ft. The elevation of the grade at the 
 P. C. at Sta. 29 is 122.8604; hence, the elevation of grade at 
 the P. T. at Sta. 33 is 122.8604 + 4.7608 = 127.6212 ft., 
 which we record on the profile together with the grade, viz., 
 + 1.1902, written above the grade line. The P. C. of the 
 next curve is at Sta. 37 + 50, giving an intermediate 
 tangent of 450 ft. = 4.5 stations. The grade for tangents 
 is + 1.4302 ft. per station; hence, the total rise on the 
 tangent is 1.4302 X 4.5 = 6.4359 ft. Adding 6.4359 ft. 
 to 127.6212 ft., we have for the elevation of grade at Sta. 
 37 + 50, 134.0571 ft., which we record on the profile, to- 
 gether with the rate of grade for tangents. 
 
 The next curve is 6° and the compensation in grade per 
 station is .03 ft. X 6 = .18 ft. The grade on this curve will, 
 therefore, be 1.4302 — .18 = 1.2502 ft. per station. The 
 length of the curve is 450 ft. = 4.5 stations, and the total 
 rise in grade on this curve is + 1.2502 ft. x 4.5 = 5.6259 ft. 
 The elevation of the grade at Sta. 37 + 50, the P. C. 
 of the curve, is 134.0571. The elevation of the grade at 
 Sta. 42, the P. T., is, therefore, 134.0571 + 5.6259 = 139.683 
 ft., which we record on the profile together with the rate of 
 grade on the 6° curve, viz. , + 1. 2502. The P. C. of the next 
 curve is at Sta. 44 + 25, giving an intermediate tangent of 
 225 ft. = 2.25 stations. The total rise on the tangent is, 
 therefore, 1.4302 X 2.25 = 3.21795 ft. The elevation of grade 
 at the P. T. at Sta. 42 = 139.683; therefore, the elevation of 
 grade at Sta. 44 + 25 = 139.683 + 3.21795 ft. = 142.90095 ft., 
 which we record on the profile together with the grade, viz., 
 + 1.4302. The last curve is 9° and the compensation in 
 
RAILROAD LOCATION. 
 
 849 
 
 30 
 
 grade per station is 
 .03 ft. X 9 = .27 ft. 
 The grade on 9° curve 
 is, therefore, 1.4302 — 
 .27 = 1.1602 ft. per sta- 
 tion. The length of 
 the curve is 550 ft. = 
 5.5 stations, and the 
 total rise on the curve 
 is 1.1602X5.5 = 6.3811 
 ft. The elevation of 
 grade at Sta. 44 + 25, 
 the P. C. of the 9° 
 curve, is 142.90095 ; 
 hence, the elevation of 
 grade at the P. T., 
 at Sta. 49 + 75, is 
 142.90095 + 6.3811 = 
 149.28205 ft., which we 
 record on the profile to- ? ^q 
 gether with the grade, % 
 + 1.1602. The end of 
 the line is at Sta. 53, 
 giving a tangent of 
 225 ft. = 2.25 stations. 
 The rise on this tan- 
 gent is 1.4302x2 25 = 
 3.21795 ft., which we 
 add to 149.28205, the 
 elevation of the P. T. at 
 Sta. 49+75. The sum, 
 152.5 ft., is the eleva- 
 tion of grade at Sta. 
 52. The sum of the 
 partial grades should 
 equal the total rise be- 
 tween the extremities 
 of the grade line. 
 
 60 
 
850 
 
 RAILROAD LOCATION. 
 
 The points where the changes of grade occur are marked on 
 the profile in small circles, which are connected by fine lines 
 which represent the grade line. These points of change are 
 projected on a horizontal line at the bottom of the profile. 
 Those portions of this line representing curves are dotted, 
 and those portions representing tangents are drawn full. 
 The points of curve P. C. and P. T. are marked in small 
 circles on this horizontal line, and lettered as shown in the 
 figure. 
 
 Where the grades are light and the curves easy, there will 
 be no need of compensation for curvature. Where the grades 
 exceed .5 per cent, and the curves 5°, compensation should 
 be made. 
 
 1 438. Changing of Grade Lines. — Unforeseen diffi- 
 culties sometimes arise during construction which warrant 
 the changing of grade lines, but these occasions are rare. 
 If the final grade line has been properly considered, it would 
 better remain unchanged. The engineer should learn to 
 make up his mind and stick to it. 
 
 1 439. Vertical Curves. — Vertical curves are used to 
 round off the angles formed by the meeting of two grade 
 
 lines. Let A C and C B, Fig. 375, be two grade lines 
 meeting at C. 
 
 These grades are given by the rise per station in going in 
 some particular direction. Thus, starting from A, the 
 grades A C and C B may be denoted by g and g' \ that 
 is, the grade for any station on y^ (7 is found by adding the 
 
RAILROAD LOCATION. 851 
 
 rate of grade g to the grade of the preceding station, and 
 the grade for any station on C ^ is found by adding the rate 
 of grade g' to the grade of the preceding station. But C B 
 is a descending grade. Therefore, the rate^', to be added 
 to each station, is a minus quantity and^' is negative. 
 
 The parabola furnishes a simple method of putting in a 
 vertical curve. 
 
 1440. Problem.— Given the grade ^ of A C, Fig. 375, 
 the grade ^' of C B, and the number of stations n on each 
 side of C to the tangent points A and B, to unite these 
 points by a parabolic vertical curve : 
 
 Let A £ B he the required parabola. Through B and C 
 draw the vertical lines F K and C H, and produce A C to 
 meet F K in F. Through A draw the horizontal line A K 
 and join A and /?, cutting C H \n D. Then, if a represents 
 the vertical distance of the first station M on the curve 
 from the corresponding station 7" on the tangent, the ver- 
 tical distance at the second station will be the square of 
 2, or 4 «, and at the third station the square of 3, or 9 «, 
 and at B, which is 2 « stations from A, the vertical distance 
 to the curve will be the square of 2 « or 4 «" « ; that is, F B =^ 
 
 FB 
 4 «' a, and a = - — j. To find a, it will first be necessary 
 
 to find F B. This may be done by means of the following 
 formula, in which g and g' are the grades mentioned in 
 Art. 1439, and n is the number of stations between A 
 and C: 
 
 4 n 
 
 (lOl.) 
 
 Having determined the value of a, the distances of the 
 several stations in A C and C B from the curve, viz., a, 4 a, 
 9 a, 16 n, etc., are readily known. Let T and F' be the 
 first and second stations on the tangent A C, and if from T 
 and T' perpendicular lines T P and T' P' be drawn to the 
 horizontal line A K, T P, the height of the first station T 
 above A, equals^, and 7 ' P' equals 2^, and for succeeding 
 stations we shall find the heights 3 g, 4 g, etc. We have 
 
852 RAILROAD LOCATION. 
 
 already found T M—a, T' M' = A: a, etc. The heights of 
 the curve above the level of A will, therefore, be as follows: 
 K\.M, heights TP- T M=g- a; at J/', height = T' P' 
 
 — T' M' = 2g-Aa, and at E, height =C H - C E^Zg 
 
 — 9 rt, and for succeeding points A g — 16 «, etc. To find 
 the grades for the curve at successive stations from A, that 
 is, the amount which must be added to the grade or height 
 of one station'to equal the grade of the following station, we 
 must subtract each height from the next following height. 
 Thus, calling the height of A 0, we have (^ — «) — = ^ 
 
 — a^ the height of M above A K, called the grade of M; 
 (2^—4 a) —{g — (i) = g — 3 a, which must be added to the 
 grade of J/ to find the grade of J/' ; (3^ — 9 «) — (2 ^ — 4 «) 
 = g— 5 a, which must be added to the grade of Af to find 
 the grade of E. The succeeding quantities are (4^ — 16 a) 
 -{3g-9a)=g-'7 a,{5 g- 25 a) - (4^-16 a) = g - 
 9 a, and {& g —ZQ a) — {5 g — 2b a) = g — \l a. The suc- 
 cessive grades or additions for the vertical curve. Fig. 
 375, are ^ - ^, g-Z a, g- 5 a, g-7 a, g-d a, and 
 g-lla. 
 
 In finding these grades, strict regard must be paid to the 
 algebraic signs. The results are then general. 
 
 1441. Example 1. — Let the number of stations on each side 
 of C, Fig. 375, be 3, and let A Che an ascending grade of 1.2 feet per 
 station, and C B a. descending grade of .8 ft. per station. Assume the 
 elevation of the grade at Sta. A to be 120 feet, and find the grade at 
 each station from A to B. 
 
 Solution. — Here « = 3, ,^ = + 1.2 ft., and ^' = — .8 ft. Substitu- 
 
 -^' 1- 1.2-(- 
 -i-2-,we have a — . ^ ^ 
 
 — 1 AAA ft- onH fVio crfiir1*»c frf\rr\ A \r\ 
 
 12 
 
 p— z' 1 2 — (— .8) 
 
 ting known values in formula 1 Ol , a = , ,we have a — 
 
 4« 
 
 2 
 
 Yq = .1666 ft., and the grades from A to B will be 
 
 Heights of Curve 
 above A. 
 g- a =1.2- .167= 1.033 ft. 1.033 ft. 
 g- Za = 1.2 - .500 = .700 ft. 1.733 ft. 
 ^-5^=1.2- .833= .367 ft. 2.100 ft. 
 ^- 7a =1.2-1.166= .034 ft. 2.134 ft. 
 ^- 9a =1.2-1.500=- .300 ft. 1.834 ft. 
 g - 11a = 1.2 - 1.833 = - .633 ft. 1.201 ft. 
 
RAILROAD LOCATION. 
 
 853 
 
 Since the elevation of the grade at Sta. A, Fig. 375, is 120.00 feet, the 
 grades for the following stations of the vertical curve will be : 
 
 Elevation of „^ ^. Elevation of 
 
 tation. „ . Station. „ . 
 
 Grade. Grade. 
 
 A 120.000 ft. O 122.134 ft. 
 
 M 121.033 ft. 
 
 M' 121.733 ft. 
 
 E 122.100 ft. 
 
 Ans. 
 
 R 121.834 ft. 
 
 B 121.201 ft. 
 
 Example 2. — Let A C, Fig. 376, be a descending grade of 1.0 ft. per 
 station, and C B an ascending grade of .5 ft. per station. Let the 
 vertical curve include 2 stations each side of C. Find the grade at 
 each station from A \.o C. 
 
 Solution.— Here g =— 1.0 ft., ^' = + .5 ft., and « = 2. Substituting 
 
 GTade=120.0 
 
 Fig. 376. 
 
 these values in formula lOl, a=.'^^ — ^— , we have 
 
 4 « 
 
 -1.5 
 
 a^-\.0-{.h) _ 
 
 = — .IS'* 5, and the four grades required will be: 
 
 Ans. 
 
 g- a = 
 g-Za = 
 g -oa = 
 g-'7a = 
 
 1.0 -(- .1875) = 
 1.0 -(- .5625) = 
 1.0 -(- .9375) = 
 1.0 -(-1.3125) = 
 
 1.0+ .1875 = -.8125 ft. 
 1.0 + .5625 = - .4375 ft. 
 1.0+ .9375 =- .0625 ft. 
 1.0 + 1.3125= + .3125 ft. 
 
 It will be seen that after finding the first grade, the suc- 
 ceeding grades are found by a continual subtraction of 2 a. 
 Thus, in the first example, each grade after the first is .333 ft. 
 less than the preceding grade. In the second example, a is 
 a negative quantity, and each grade after the first is. 375 ft. 
 greater than the preceding grade. 
 
 The grades in the foregoing examples are calculated for 
 whole stations, and are sufficient for all purposes except for 
 track laying or ballasting, when- grade stakes on the vertical 
 curve should be driven at intervals of 25 feet, and the grades 
 must be calculated for these sub-stations. To do this, let g" 
 
854 RAILROAD LOCATION. 
 
 and^' represent the grades for a sub-station of 25 feet, and 
 11 the number of such sub-stations on each side of the 
 intersection of the grade lines. 
 
 Example. — In the last example divide the curve into sub-stations of 
 25 ft. each. Assume the grade at A to be 130 feet, and find the grade 
 at each sub-station. 
 
 Solution.— Here ^=—.25 ft, ^' = +.125 ft., and « = 8. Sub- 
 stituting these values in formula lOl, <? = . * , we have a-= 
 -.25 -(.125) ^ -^ ^ _ ^^^^2 ^^^ ^^^^ g^^^^ .^^ therefore. 
 
 ^ - rt = - .25 - (- .01172) = - .23828. Each subsequent grade in- 
 creases 2a; that is, —.02344, and we have the following: Grade at 
 Sta. 2 = - .21484; Sta. 3, - .19140; Sta. 4, - .16796; Sta. 5, - .14452; 
 Sta. 6, -.12108; Sta. 7, -.09764; Sta. 8, -.07420; Sta. 9, -.05076; 
 Sta. 10. - .02732; Sta. 11, - .00388; Sta. 12, + .01956; Sta. 13, + .04300; 
 Sta. 14, +.06644; Sta. 15, +.08988; Sta. 16, +.11332. 
 
 The distance A />', Fig. 376, is 400 feet divided into 16 sub-stations of 
 25 feet each. Since the grade of A is 120.0 feet, the grades of the fol- 
 lowing stations will be: 
 
 f Stations. Grades. Stations. Grades. 
 
 A 120.000 9 118.699 
 
 1 119.762 10 118.672 
 
 2 119.547 11 118.668 
 
 3 119.355 12 118.688 
 
 4 119.187 13 118.731 
 
 5 119.043 14 118.797 
 
 6 118.922 15 118.887 
 
 7 118.824 16, i5... 119. 000 
 
 8 118.750 
 
 The purpose served by vertical curves will be at once ap- 
 parent to the student. The sudden and severe stress upon 
 the rolling stock caused by passing from one grade to 
 another results in great harm to rolling stock and much 
 discomfort to passengers. Vertical curves should always be 
 put in the grade during construction. Where the meeting 
 grades are very slight, no curve is necessary. 
 
 1 442. Preliminary Estimates. — Having established 
 the final grades, the next work of the engineer is the pre- 
 liminary estimate. This estimate gives in detail the approx- 
 imate quantities of all material to be handled in the work of 
 
 Ans. 
 
kAILROAD LOCATION. 856 
 
 construction, and of all probable cost attending such work. 
 Work and materials to be furnished, together with the prices 
 ruling in the locality where the work is to be done, are 
 classified as follows: 
 
 1 443. Classification of Preliminary Estimates. — 
 
 1. Clearing per acre $20.00. 
 
 ^ Earth, per cubic yard 20c. 
 
 } Loose rock, per cubic yard. . 40c. 
 
 ■ ' ' ' ( Solid rock, per cubic yard. . . 80c. 
 
 Overhaul exceeding 1,000 feet, per cubic yard Ic. 
 
 Piles, per lineal foot 25c. to 30c. 
 
 3. Trestling. \ Frame, per 1,000 ft. bd. meas- 
 ure, Ga. pine $35.00. 
 
 Ist-class rock-face range 
 
 work, per cubic yard $10. 00 to $12 00. 
 
 '2d-class good lime mortar 
 
 rubble, per cubic yard. . . . $8.00. 
 
 Dry rubble, per cubic yard. . $4. 00 to $4. 50. 
 Riprap per square yard, in 
 
 place $1.50to$2.50. 
 
 Wooden 
 
 [ron and steel 
 
 4. Masonry.. ■< 
 
 5. Bridgmg . -j ^^ 
 
 Classification not only affects price, but quantity. Cuts 
 in solid rock, which are the most costly, stand at a slope of 
 ^ horizontal to 1 vertical, while earth ordinarily requires a 
 slope of 1 horizontal to 1 vertical, and sometimes as flat a 
 slope as 1|^ horizontal to 1 vertical. All materials excavated, 
 and all masonry, are estimated by the cubic yard. Trest- 
 ling is estimated by the 1,000 feet, board measure, and 
 piling by the lineal foot. Wooden bridges, of moderate 
 span, are sometimes estimated at a fixed price per 1,000 feet 
 for lumber, and a fixed price per lb. for iron, but generally 
 a special estimate is made for each bridge. The cost of 
 bridges increases rapidly as the span increases. In metal 
 bridges the cost will increase about as the square of the 
 
856 
 
 RAILROAD LOCATION. 
 
 span, i. e., if one bridge has twice as great a span as another, 
 the first will cost the square of 2 or 4 times as much as the 
 second. 
 
 1444.* Quantities. — The material to be handled in 
 grading the roadbed is generally estimated by level cuttings, 
 which process assumes that the cross-section surfaces are 
 
 1/ 9.0 ft 
 
 t 4.4ft 
 
 Fig. 377. ' 
 
 level, and the areas are calculated from the center cuts and 
 Ji//s. Let Fig. 877 represent the actual cross-section at a 
 given station, and Fig. 378 the cross-section based upon the 
 center cut. The area of the section A B C D m Fig. 377, 
 calculated from the actual cross-sections, is 160.78 sq. ft. 
 The area of the section A' B' C D\ in Fig. 378, calculated 
 
 Cut 6.4 ft 
 
 Cut 6.4 ft 
 
 JS.4- -i 
 
 15.4.^- > 
 
 1^ 6^ 1— 
 
 Fig. 378. 
 
 Cut 6.4ft 
 
 V 6d . 
 
 from a level section, with the same center cut, viz., 6.4 feet, 
 is 156.16 sq. ft., giving a discrepancy of 4.62 sq. ft. ; that is, 
 the area of the section, calculated by level cuttings, is 4.62 
 sq. ft. less than the area calculated from the actual cross- 
 sections. This deficiency is about 3 per cent., but where 
 the slope is very steep, the difference increases rapidly. As 
 the invariable custom is to add 10 per cent, to the estimated 
 
RAILROAD LOCATION. 
 
 857 
 
 
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858 RAILROAD LOCATION. 
 
 cost, such addition will fully cover any deficiency resulting 
 from table calculations. Where time is not an object, it is 
 good practice to take the slopes with a clinometer and plat 
 them on cross-section paper. The estimate thus obtained 
 will be a close approximation to the actual quantities 
 handled in the work of construction. For work in the 
 Northern and Middle States the following rates of slope are 
 standard: For embankments, H horizontal to 1 vertical; 
 for earth cuts, 1 horizontal to 1 vertical, and for rock cuts, 
 ^ horizontal to 1 vertical. In Western and Southern States 
 it is the usual custom to give to cuts the same slope as to 
 embankments, viz., 1^ horizontal to 1 vertical. 
 
 1445. Traut^vine's Engineers' Pocket Book con- 
 tains complete tables of level cuttings for standard widths 
 of roadway, both single and double track. The slopes are 
 given for earthwork, both excavation and embankment. 
 The quantities are calculated for sections 100 feet apart. If 
 the sections are taken oftener than each 100 feet, the quan- 
 tities will be proportionally less. The table of Level Cut- 
 tings shows the arrangement for single-track excavation, 
 roadway 18 feet wide, slopes 1 horizontal to 1 vertical. 
 
 The use of this table is explained as follows: Suppose the 
 
 center cut at vStation 10 is 1.5 ft. and the center cut at 
 
 Station 11 is 3.0 ft. The sum of these two center cuts, 
 
 1.5 -|- 3.0 = 4.5 ft. The mean or average center cut at 
 
 4 5 
 these stations is, therefore, -jr- = 2.25ft. As the nearest 
 
 tenth is always used, we will call the average cut between 
 Stations 10 and 11, 2.2 ft. 
 
 Referring to the table, we find in the column headed 
 depth of cut in feet, the figure 2, and on the same horizontal 
 line, under the column headed .2, we find 1(54.0, which is 
 the number of cubic yards of material to be excavated 
 between Stations 10 and 11. 
 
 The quantities are given for center cuts from .1 foot to 60 
 feet. For cuts greater than 60 feet, the quantities are 
 calculated for only even feet. 
 
RAILROAD LOCATION. 
 
 859 
 
 1446. Sections. — The line is divided into lengths of 
 one mile each, called sections, which are numbered in regu- 
 lar order, the first mile of the line 
 being section 1, the second mile section 
 2, and so on. At the division points, 
 i. e. , where one section ends and another 
 begins, posts are set up with boards at- 
 tached, facing in both directions, with 
 the number of the section towards which 
 they face written in large figures. See 
 Fig. 379. 
 
 The section boards enable one to 
 readily locate any particular part of the 
 line. 
 
 1447. Right of Way.— Before 
 construction can be commenced, the ., 
 right of way must be secured, a matter 
 always attended by more or less difficulty. 
 The standard width of right of way is 
 100 feet, though, in some cases, but 4 rods or 66 feet is 
 adopted, with additional widths wherever needed. 
 
 Where the local needs for the road are great, and the 
 enterprise popular, much right of way is often donated, a 
 nominal sum, usually one dollar, being paid as considera- 
 tion. The ordinary mode of securing right of way is by 
 direct purchase. The company employs an agent specially 
 fitted for his business, who makes the most advantageous 
 bargains possible with the different owners. When there is 
 failure to agree on price, a common alternative is to leave 
 the question to three arbitrators, each of the parties to the 
 transaction choosing one and agreeing together upon the 
 third. The arbitrators unite upon a valuation-which the 
 contracting parties have agreed to accept. Occasionally, an 
 owner, taking advantage of the situation, attempts extor- 
 tion, in which case the only recourse is to the laxv of euii- 
 nent domain. Articles of condemnation are taken out and 
 appraisers appointed by the court, who fix the amount of 
 
800 RAILROAD LOCATION. 
 
 compensation. The process is always attended by expense, 
 delay, and vexation, and should only be a last resort. 
 
 1448. Right of Way Maps. — A careful survey is 
 made of each separate piece of property bought for right 
 of way or station grounds, and stone corners established for 
 future reference. These surveys should be platted in a 
 "right of way" book in the same order in which they occur 
 on the line, and a copy of the contract for and description 
 of the property written on the same page or that adjoining 
 the plat. The plat should specify content, boundaries, 
 corners, and any information which may be of future use. 
 A copy of the contract and a tracing of the plat is delivered 
 to the person or persons from whom the property is bought. 
 
 1449. Specifications. — Specifications describe the 
 manner in which the work of construction is to be con- 
 ducted and the materials to be used in structures. 
 
 Specifications are of two kinds; \\z., gc7ieral, those de- 
 scribing the different general classes of work, and special, 
 those referring to a particular structure or other work 
 requiring special plans or processes. In this work only 
 general specifications will be given. 
 
 A., B., & C. R. R. 
 
 GENERAL SPECIFICATIONS FOR GRADING AND 
 BRIDGING. 
 
 1. Clearing. — The surface is to be cleared the full 
 width of right of way and such additional width as the 
 engineer in charge shall direct, of all trees, bushes, and 
 other perishable matter. 
 
 2. Grubbing. — In cuttings, and in embankments where 
 the fill is two feet and less, all trees and stumps between the 
 slope stakes must be grubbed out; where the fill is more 
 than two feet, all trees and stumps must be cut down even 
 with the surface of the ground. No payment will be made 
 for grubbing. 
 
RAILROAD LOCATION. 861 
 
 3. Grading. — Under this head will be included all ex- 
 cavations and embankments required for the formation of 
 the roadbed, side tracks, and station grounds; the founda- 
 tion pits for bridges, culverts, and cattle-guards; the cutting 
 of ditches and drains contiguous to the roadbed; all excava- 
 tions and embankments in constructing farm and highway 
 crossings, and in the changing of channels for streams. 
 
 4. Borrow Pits. — The embankment shall be con- 
 structed from material borrowed from the right of way. 
 No embankment shall be constructed from material de- 
 posited by casting without special permission of the engineer 
 in charge. If borrow pits are required outside the right of 
 way, they shall be procured by the railroad company. 
 
 5. Provision for Settling. — Cuts and ditches shall be 
 measured in excavation; all other work shall be measured 
 and paid for in embankment. The embankments shall be 
 made from 5 to 10 per cent, higher than the established 
 grades. This additional percentage is an allowance for 
 shrinkage, and shall be fixed by the resident engineer. No 
 allowance for such shrinkage shall be made in the estimate. 
 
 6. Single-Track Work. — In single-track work the 
 roadway shall be eighteen feet in width at sub-grade in cuts, 
 and fourteen feet in width on embankments. The side 
 slopes of earth cuts shall be one horizontal to one vertical, 
 and of rock cuts one-quarter horizontal to one vertical, un- 
 less otherwise specified by the engineer in charge. The side 
 slopes for embankments shall be one and one-half horizontal 
 to one vertical. A berme six feet in width shall be left 
 between the slope stakes and the edge of the borrow pits. 
 
 7. Double-Track Work. — In double-track work the 
 roadway shall be twenty-eight feet in width at sub-grade in 
 cuts, and twenty-four feet in width on embankments. Side 
 slopes of earth cuts shall be one horizontal to one vertical; 
 of rock cuts, one-quarter horizontal to one vertical, unless 
 otherwise specified by the engineer in charge. The side 
 slopes for embankments shall be one and one-half horizontal 
 
m RAILROAD LOCATION. 
 
 to one vertical. A berme six feet in width shall be left 
 between the slope stakes and the edge of the borrow pit. 
 
 8. Borrow Pits. — A space three feet in width shall be 
 left between the borrow pits and the right-of-way lines. 
 The slopes of borrow pits shall not be steeper than one and 
 one-half horizontal to one vertical, and shall generally be of 
 such depth as will secure proper drainage. 
 
 9. Ditches. — All excavations shall be finished with side 
 ditches of such dimensions as the engineer shall direct, and 
 to prevent the washing of slopes, ditches shall be cut on the 
 up-hill side, such ditches to be not less than four feet from 
 the top of the slope. 
 
 10. Excavation. — The classification for all excavated 
 material will be as follows: 
 
 Earth will include clay, sand, gravel, loam, decomposed 
 rock, and slate, and all other matters of an earthy kind, how- 
 ever hard, stiff, or compact, and all boulders containing less 
 than three cubic feet each. 
 
 Loose rock will include all stone and detached rock 
 found in separate masses, containing not less than three 
 cubic feet nor more than one cubic yard; also, all slate, 
 coal, or other rock, soft or loose enough to be removed with- 
 out blasting, although blasting may be resorted to; also, 
 stratified limestone ip layers eight inches thick and under, 
 separated by strata of clay. 
 
 Solid rock will include all rock in masses of more than 
 one cubic yard which can not be removed without blasting. 
 
 11. Foundation excavation above the general water 
 level at the time shall be excavated by the contractor and 
 paid for at his grading prices. The residue of foundation 
 work will be executed by the contractor, and paid for by 
 the company at actual cost, with ten per cent, added for 
 contractor's supervision, use of tools, etc. The price per 
 yard bid for masonry will include centerings, scaffoldings, 
 and all other expenses connected with the work, excepting 
 the foundation work above specified. 
 
RAILROAD LOCATION. 863 
 
 12. Tunnel Excavation. — The price for tunnel ex- 
 cavation will include all excavation between the portals of 
 the tunnel proper, and within the area of the cross-section, 
 as determined by the engineer, and it will include also all 
 temporary supports, scaffolding, etc. The area of the cross- 
 section for tunnel excavation will be measured six inches 
 outside the wall and arch, and all excavation outside of this 
 cross-section will not be paid for unless in the opinion of the 
 engineer such irregularities could not be prevented by the 
 exercise of proper care and judgment in excavating, and 
 paid for at such prices as the engineer shall determine, 
 
 13. Masonry. — Masonry shall be built according to 
 plans furnished by the engineer, and estimated and paid for 
 by the cubic yard. Masonry in which mortar is required shall 
 be kept well wet while being laid, and every stone shall be 
 clean and thoroughly wet when laid. Arches shall be built 
 on substantial centers extending the entire length of the 
 arch, and the mode of construction, as well as the plan, shall 
 be approved by the engineer. Centers shall not be removed 
 or loosened without the direction of the engineer. The 
 price per yard shall in all cases include the furnishing of 
 centers, scaffolding, and all other cost and expense incidental 
 to the completion of the work. All joints of face walls of 
 masonry laid in mortar shall be suitably pointed, and the 
 work finished to the satisfaction of the engineer. 
 
 Tunnel Masonry. — The masonry for tunnels and all 
 bridge piers and abutments shall be of Rock Face Range 
 Work. All of the arch stones shall be well and smoothly 
 cut on the beds, ends, and face, and shall be laid so that 
 their beds shall be at right angles to the tangent of the 
 curve. The beds of each stone shall have full and solid 
 bearings, and the joints shall be close and straight. 
 
 Walls and arches shall belaid in regular courses of uniform 
 thickness. No course shall be less than four inches in thick- 
 ness. The faces shall be Rock Face with edges pitched to 
 straight and true lines. 
 
 The vacancies behind tunnel walls and above tunnel arches 
 
864 RAILROAD LOCATION. 
 
 shall be filled with concrete or dry packing, at the discre- 
 tion of the engineer. All packing must be well rammed in 
 place as the work progresses. 
 
 First-Class Masonry. — In all first-class masonry the 
 stones of each course shall be gauged to the same thickness, 
 and after each course is laid and grouted or filled with mor- 
 tar, the tops of the stones shall be dressed so as to bring the 
 top of the course to a common level. 
 
 Stretchers shall be not less than three feet in length, with 
 bed not less than sixteen inches. Headers shall be not less 
 than eighteen inches in width, nor less than three times 
 the thickness of the course in length. Stretchers and 
 headers should be in the proportions of 3 to 1. All face 
 stones shall be dressed full to the square for their entire 
 length and width, and shall be so cut and laid as to have 
 a full bearing for their entire bed. All joints shall be 
 close and straight, and be so broken as to make a perfect 
 bond. 
 
 Backing shall be of good-sized and well-shaped stones and 
 so dressed that each stone shall lie firmly on its bed. The 
 backing shall be laid with reference to each succeeding 
 course, affording good header bearers and so bonding the 
 whole into one solid mass. All stones shall be laid in mor- 
 tar, and if the engineer shall so direct, the vertical joints 
 shall remain open until the course is finished. All unfilled 
 parts of the wall shall be filled with mortar or grout. The 
 tops of the walls shall be coped with large broad stones, not 
 less than three feet in length, the same to be well-dressed 
 on the top and ends, and all face joints pointed with good 
 mortar. 
 
 Culvert Masonry. — Arched and box culverts shall be 
 built of good-sized and well-shaped stones, and laid dry 
 unless otherwise directed by the engineer in charge. Stones 
 shall be straightened on faces and ends with fair proportion 
 of headers, and laid with joints broken so as to form a com- 
 pact and substantial body. Covering stones shall be of such 
 length and thickness as the engineer in charge shall direct. 
 
RAILROAD LOCATION. 8G5 
 
 The top courses of wing waits shall be of wide stones with 
 good joints, so as to form a good and smooth coping. 
 
 14. Pavement. — Between the side walls and at the 
 ends of culverts and bridges where required, paving will be 
 laid of good smooth stones set on edge and well fitted, so as 
 to make a close, smooth surface. Paving shall be of such 
 thickness as the engineer shall direct, and it shall be secured 
 at ends and sides by curb stones not less than two feet in 
 depth. To prevent undermining, broken stone shall be 
 deposited outside the curbing. Paving will be paid for by 
 the cubic yard. 
 
 15. Mortar and grout shall be made of clean sharp 
 sand and fresh slacked lime, in the proportions of one part of 
 lime to two of sand. Mortar shall be thoroughly mixed 
 and allowed to stand until all particles of lime are thoroughly 
 slacked. Hydraulic cement to be substituted for lime at 
 the discretion of the engineer, the difference in actual cost 
 to be refunded to the contractor. The proportion of the 
 ingredients of mortar and grout may be varied at the dis- 
 cretion of the engineer. 
 
 16. Protection. — When required by the engineer, em- 
 bankments will be protected by cribbing built of round logs 
 and filled with stone, or riprap laid with beds at right angles 
 to the slope of embankment, affording a close and generally 
 smooth surface. Contractors shall hold themselves in readi- 
 ness to perform such work with promptness and dispatch. 
 Cribbing will be paid for by the lineal foot, and riprap by 
 the cubic yard — both to be measured in place. 
 
 17. Piling. — Piles shall be of white or burr oak, long 
 leaf pine, or other suitable timber, sound and without loose 
 or rotten knots. They shall measure not less than seven 
 inches in thickness at the small end, and average not less 
 than eleven in thickness. The bark must be removed before 
 driving. 
 
 18. Driving. — Piles must be driven at the places staked 
 out for them by the engineer in charge, and they must be 
 
866 RAILROAD LOCATION. 
 
 driven, if the engineer so desires, to such a depth that a 
 hammer weighing 2,000 pounds, falling upon the pile from 
 a height of twenty feet, will not sink the pile more than one 
 inch. 
 
 19. Timber. — All timber shall be of sound, straight- 
 grained white or long leafed southern pine or other suitable 
 timber, free from rotten knots or shakes, and with no sap 
 extending more than two inches from any edge. 
 
 20. Framing. — The framing shall be done in the most 
 workmanlike manner and in accordance with plans furnished 
 by the engineer. 
 
 2L Inspection. — The kind and quantity of all material 
 in the work shall be subject to the approval of the engineer 
 in charge. Timber shall be estimated in place and paid for 
 by the thousand feet,, board measure. All iron used in 
 structures will be paid for by the pound. 
 
 22. Montlily Estimates. — During the progress of the 
 work, on or about the first of every month a monthly esti- 
 mate shall be made of the kind, quality, amount, and value 
 of work done during the preceding month, eighty-five per 
 cent, of which value will be paid to the contractor on or 
 about the fifteenth of said month, and when the work is 
 completed and accepted there shall be a final estimate made 
 by the engineer of the quantity, character, and value of the 
 entire work, according to the terms of the contract, and the 
 balance, after deducting the several monthly payments, and 
 upon the contractor giving release to the company from all 
 claims or demands whatsoever, will be paid in full. 
 
 23. The contractor shall render an account monthly, 
 through the proper superintending engineer, of any extra 
 work which he may have been authorized to do; and to pre- 
 vent disputes hereafter, it is hereby understood that no bills 
 for extra work will be allowed unless authorized and ordered 
 in writing by the engineer in charge, and the bill for said 
 extra work presented at the end of the month in which the 
 work was done, and approved by said engineer. 
 
RAILROAD LOCATION. 867 
 
 24. During the progress of the work and until it shall 
 be completed and accepted by the company, it shall be the 
 duty of the contractor, at his own expense, to sufficiently 
 guard and protect the same by barriers, fences, or otherwise, 
 so as to prevent travelers or other persons from sustaining 
 injury to themselves or property by falling into any excava- 
 tion or running over any dangerous fill or embankment, or 
 over or against stumps, timber, or any material, or in any 
 other way whatsoever; and in blasting stone, the contractor 
 shall use the utmost precaution and care to avoid injuring 
 persons or property, and the contractor shall save and keep 
 the company free and harmless from the payment of any 
 damage for injury to persons or property arising from any 
 malfeasance or negligence of the contractor or of any of his 
 sub-contractors, agents, or servants. 
 
 25. The contractor shall not let or transfer his contract 
 or any part of it, or withdraw his personal attention there- 
 from, without the consent of the engineer. 
 
 26. The contractor shall put on and maintain night 
 forces at such points and to such extent as the engineer shall 
 direct. 
 
 27. In all disputes the decision of the engineer shall be 
 final. 
 
 28. By engineer is meant the chief engineer. 
 
 1450. Advertising for "Work. — A classified estimate 
 is made of the amount of work in each section, and the road 
 is advertised for contract. These advertisements name a 
 date for the opening of bids. Contractors are provided with 
 a printed copy of the general specifications and of the esti- 
 mated quantities in each section, and are allowed to take 
 such notes as they may require from the map and profile. 
 In walking over the line they can readily locate any par- 
 ticular section from the section boards. 
 
 1451. Reservations. — The company should invari- 
 ably reserve the right to reject any or all bids, in order that 
 
8G8 RAILROAD LOCATION. 
 
 they may shut out irresponsible men or prevent a combina- 
 tion of contractors from charging exorbitant prices for 
 work. 
 
 1452. Bond. — Contractors should be required to fur- 
 nish a bond signed by two responsible parties to insure the 
 proper fulfilment of their contract. This bond is usually 
 to the amount of ten per cent, of the estimated cost of the 
 work undertaken. The contract specifies the date on or 
 before which the contractor shall complete the work, and 
 often specifies a forfeit to be imposed in case of any default 
 on the part of the contractor to fulfil the conditions of his 
 contract. 
 
RAILROAD CONSTRUCTION. 
 
 1453. The Engineer Corps. — The engineer corps in 
 charge of construction differs in organization from that in 
 charge of location. In general, when construction is com- 
 menced, it is prosecuted with vigor throughout the entire 
 line, and, as the work requires constant inspection, the 
 force of engineers is considerably augmented. 
 
 1454. Subdivisions of the Line. — The entire line 
 is divided into sections of about 30 miles each, called divi- 
 sions, each division being placed in charge of a division 
 engineer. The divisions are further divided into lengths 
 of about 10 miles each, called residencies. Each residency 
 is placed in charge of a resident engineer. 
 
 1455. The Division Engineer, His Authority 
 and Duties. — The division engineer has general charge of 
 an entire division and is directly accountable to the chief 
 engineer, from whom he receives general orders relating 
 to the work of his division. He should go over his entire 
 division twice each week, giving particular directions to the 
 resident engineers for the conduct of the work and main- 
 taining a general supervision of the whole. His office 
 should, if possible, be so situated as to afford prompt mail 
 service. Telegraphic communication with the chief engineer 
 is important, though not always possible. Plans of all the 
 important structures on a division, excepting large bridges, 
 are made at the division office and forwarded to the chief 
 engineer for approval. The monthly estimates made by the 
 resident engineers of his division are inspected by the divi- 
 sion engineer, a careful record of them kept at his office, 
 and forwarded by him to the chief engineer for approval. 
 
870 RAILROAD CONSTRUCTION. 
 
 1456. The Resident Engineer, His Corps, and 
 Their Duties. — The corps in charge of each residency, 
 comprises the resident engineer, instrument man, rodman, 
 tapeman, and axman. The resident engineer has immediate 
 charge of all work on his residency, a profile of which is 
 given him with the grade lines drawn upon it, with the 
 gradients and compensation for curvature clearly stated. 
 At each watercourse shown in the profile, a brief descrip- 
 tion is written, giving the character and dimensions of the 
 structure required at that place. He is given a copy of the 
 specifications which are to guide him in making a proper 
 inspection of the work. A suitable office is provided him at 
 or as near the middle of his residency as possible, and fur- 
 nished with drawing table, drawing materials, field books, 
 pads, and official stationery. A horse and strong two-seated 
 buckboard are an important part of his outfit, especially 
 when in thickly settled country, where the line of road is 
 readily accessible from public highways. 
 
 The first duty of the resident engineer is to check the 
 alinement and levels on the line of his work, transferring 
 bench marks from trees or rocks, which are liable to be dis- 
 turbed, to permanent objects far enough from the center 
 line to be outside of the slope stakes. 
 
 1457. Setting Slope Stakes. — His next work is set- 
 ting slope stakes, commonly called cross-sectioning, 
 which consists of setting stakes in the ground at the points 
 which will mark the top of the cut or foot of the slope of the 
 finished roadway. The following dimensions are suitable 
 for cross-section stakes: Length, 2 feet; width, 2 inches, 
 and thickness, 1 inch. They should be planed on one side 
 to admit of easy marking, and sharpened for driving. In a 
 country of average smoothness, the level, rod, and tape 
 are used in locating slope stakes; but in very rough locali- 
 ties, the Y level is used to carry the continuous line of 
 levels, while the side elevations, from which the slope stakes 
 are located, are determined by means of the hand level 
 and rods. 
 
RAILROAD CONSTRUCTION. 
 
 871 
 
 ^ 1^ 8 
 
 The process of setting slope stakes is illustrated in Figs. 
 380 and 381. In Fig. 380, the elevation of the grade is 
 103.0 feet. The height of in- 
 strument A is 97.5 feet, and, 
 hence, the instrument is 5.5 
 feet below grade. The rod read- 
 ing at the center line is CO feet, 
 hence, the surface of the ground 
 at the center line is below 
 grade, i. e., there must be a 
 fill, the amount of which is 
 made up of two quantities, viz. : 
 First, the difference between 
 the elevation of grade and the 
 height of instrument ; and, sec- 
 ond, the rod reading at the 
 center line. 
 
 The first of these quantities is 
 5. 5 feet, the second 6.0 feet, and 
 their sum, 11.5 feet, is the 
 amount of the fill at center. If 
 this cross-section is taken at a 
 full station, there will already 
 be a stake in place, and the Jil/ 
 is marked on the back of the 
 stake F. 11.5. If the section is 
 taken at an intermediate point, 
 i. e., a sub-station, say 20 + 50, 
 the center line is located by rang- 
 ing in from the stakes at the 
 regular stations and the stake 
 is marked 20 -j- 50 on one side 
 and the fill, F.11.5, on the other 
 side, and the stake driven with 
 the numbering facing Station 
 20. The s/ope stakes are located by holding the leveling rod 
 where, in the judgment of the rodman, the foot of the 
 slope of the completed embankment will be. In Fig. 380, 
 
872 
 
 RAILROAD CONSTRUCTION. 
 
 the rod reading at the right of the center line is 9.5 feet, 
 which, added to 5.5 feet, the difference between the height 
 of instrument and ^ 
 
 grade, gives a fill of «; 
 
 15 feet. The natural 
 slope of earth is one 
 and one-half horizon- 
 tal to one vertical, 
 called a slope of 1^ 
 to 1. Therefore, in 
 a fill of 15 feet, the 
 foot of the slope will 
 be 1^ times 15, which 
 is 22.5 feet from the 
 top of the slope, to 
 which must be added 
 one-half the width of 
 the roadway, viz., 8 
 feet, making 30.5 
 feet from the center 
 line. The rod is ac- 
 cordingly held at 30.5 
 feet from the center 
 line. If the rod read- 
 ing at this distance 
 is the same, i. e. , 9.5 
 feet, it marks the 
 foot of the slope, and 
 a stake marked F. 
 15.0 is driven in the 
 place of the rod. 
 Usually the rod will 
 not read exactly the * 
 same when held at 
 the calculated dis- 
 tance, and another calculation will be necessary, two trials 
 generally proving sufficient. In Fig. 381, the right slope 
 stake is fixed in the same way. The left slope stake is 
 
 -Fill 16:2- 
 
RAILROAD CONSTRUCTION. 
 
 873 
 
 located by means of rods and a hand level. First, a point 
 C is found where the line of sight from the level A cuts 
 the surface of the ground. A cross-section rod, which is 
 similar to a transit pole, is held at this point, which is 
 5.2 feet below grade. At 5.2 feet above C, a rod is held in 
 a horizontal position, and the point D where it meets the 
 ground marked by a stake. This point is at grade, i. e., 
 where the plane of grade cuts the ground. The stake is 
 marked by two ciphers 0.0, and its location recorded in the 
 note book. By means of the rods, the left slope stake at£"is 
 located. As the left slope is in excavation, the left half of 
 the roadway will be one foot greater in width than the right 
 half, viz., 9 feet. As the slopes in excavation are but one 
 horizontal to one vertical, called a slope of 1 to 1, the dis- 
 tance of the slope stake from the center line is the sum of 
 
 sta.eo 
 
 Fig. 382. 
 
 one-half the width of the roadway, viz., 9 feet, and the depth 
 of cutting. In Fig. 381, the cut is 6.8 feet; consequently, 
 the slope stake is set at 9 + 6.8 = 15.8 feet from the center 
 line. When the cross-section is irregular, intermediate 
 readings are taken as shown in Fig. 382. 
 
 In this section, besides finding the center fill, 6.8 feet at 
 A, and the fill 14.4 feet at foot of right slope at B, and a fill 
 of 3.8 feet at C at foot of left slope, intermediate read- 
 ings are taken at D and E where the slope of the cross- 
 section changes. These readings are recorded in the note 
 books, but no stakes are driven at the points of change of 
 slope. 
 
874 
 
 RAILROAD CONSTRUCTION. 
 
 1458. Form of Cross-Section Notes. — The levels 
 are carried continuously from bench mark to bench mark, 
 the level notes being recorded on the left-hand page of the 
 note book and the cross-section notes recorded on the right- 
 
 c 
 
 o 
 
 1 
 
 c 
 •S 
 
 o 
 
 Pi 
 
 c 
 
 1— 1 
 
 > 
 
 >- 2 
 
 c 
 
 u 
 
 o 
 
 4-> 
 o 
 
 ■(-> 
 C 
 
 O 
 
 C 
 
 Left Line. 
 
 Right Line. 
 
 20 
 40 
 60 
 
 6.0 
 
 2.7 
 
 97.5 
 114.8 
 
 • 
 
 91.5 
 112.1 
 
 103.0 
 120.0 
 
 
 11.5 
 
 7.9 
 6.8 
 
 F. 9.0 
 
 21.5 
 
 C.G.8 0.0 
 
 15.8 5.0 
 
 F.3.8 F.6.8 
 
 F.15.0 
 
 30.0 
 
 F.16.2 
 
 32.3 
 
 F.7.0F.14.4 
 
 13.7 8.0 
 
 8.0 29.6 
 
 hand page. The above form of cross-section notes is simple 
 and complete, and contains the notes for Figs. 380, 381, and 
 382. 
 
 The cross-section notes are recorded in the form of frac- 
 tions, the amount of cut or fill being the numerator of 
 the fraction, and the distance of the slope stake from the 
 center line, called the side distance, being the denomi- 
 nator. 
 
 It will be seen in comparing the notes for Station 20 with 
 Fig. 380 that the rod reading at the center stake is 6.0 feet, 
 which gives a center fill of 11.5 feet. The figure shows at 
 the foot of the right slope a rod reading of 9.5 feet. The in- 
 strument man instead of determining the elevation of the 
 ground at this point by subtracting the rod reading from 
 the height of instrument and then calculating the fill by 
 subtracting the elevation of the surface of the ground from 
 the calculated grade for that station, calculates the fill in 
 this way. If a rod reading of G.O feet gives a fill of 11.5 
 feet, a rod reading of 9.5 feet must require as much more 
 filling than 11.5 feet as 9.5 feet \% greater \h2in 6.0 feet. The 
 
RAILROAD CONSTRUCTION. 
 
 875 
 
 
 «5l 
 
 or 
 
 O 
 
 "S^" 
 
 *« 
 
 
 «- 
 «■ 
 
 •5" 
 
 - -*H- 2 6 
 
 -C- 
 
 
 difference 9.5 — 6.0 = 3.5 feet; 11.5 + 3.5 = 
 15.0 feet, i, e., a rod reading of 9.5 feet 
 requires a fill of 15.0 feet. 
 
 In the notes for Sta. GO, corresponding to 
 Fig. 382, it will be observed that the inter- 
 mediate readings taken at D and £ are re- 
 corded in the same order in which they are 
 taken. The calculations of the side dis- 
 tances are simple problems in mental arith- 
 metic, and, with a little practice, they can 
 be made with great rapidity. A tape 
 especially adapted to cross-section work is 
 graduated on both sides, one side giving 
 the varying fills from 1 foot to 28 feet, and 
 the other side being graduated to feet and 
 tenths of a foot. Fig. 383 illustrates the 
 principle upon which the tapes are made. 
 
 As shown in the figure, the eight-foot 
 mark on the right side of the tape corre- 
 sponds with the zero mark on the reverse 
 side. The reason for this is that, whatever 
 the fill, the slope stake must be placed at 
 least eight feet from the center line in 
 order to afford sufficient width for the road- 
 way. Each division representing tenths of 
 feet of filling is equivalent to 1^ tenths of 
 feet of lineal measurement, that is, a fill of 1 
 foot, as marked on the reverse side of the 
 tape, corresponds to the division 9.5 feet 
 on the right side of the tape. In using the 
 tape, a man stands at the center stake 
 holding the tape case. The rodman holds 
 the end of the tape besides carrying the 
 rod. The man at the center stake lines in 
 the rodman, that is, he places him as 
 nearly at right angles to the center line 
 as he can estimate by the eye. The rodman 
 
876 RAILROAD CONSTRUCTION. 
 
 first holds the rod at where he judges will be the foot of 
 the slope. The instrument man calculates the fill and 
 calls the amount of the fill to the tapeman, who finds on 
 the reverse side of the tape the numbers corresponding to 
 the given fill, and holds the tape at that point on the center 
 stake, causing the rodman to approach or recede from the 
 center line according as his calculation has differed from the 
 true one. Again, a rod reading is taken and the amount of 
 the fill called out, and the corresponding fill being found on 
 the tape, the rodman is checked again by the level. Two 
 trials, unless the slopes are very irregular, will generally be 
 sufficient. 
 
 1459. Clearing. — All trees, logs, and bushes are 
 cleared from the right of way. Ordinarily, this work is let 
 by contract at a fixed price per acre to experienced woods- 
 men. A skilful axman will fall and trim more trees in one 
 day than five inexperienced men, and the work will be bet- 
 ter done. The resident engineer should require the con- 
 tractor to clear the right of way immediately after his 
 taking charge of the work, as the work of staking out must 
 be deferred until after the clearing is completed. As all 
 timber on the right of way belongs to the railroad company, 
 the resident engineer should require the contractor to avoid 
 unnecessary destruction of merchantable timber while clear- 
 ing the right of way. Timber suitable for cross-ties should 
 be worked up at once, the ties being piled in safe places and 
 in such form as will admit of rapid seasoning. Logs large 
 enough for boards and square timber are piled well out of 
 reach of the work of construction. Clearing will cost from 
 $20 to $50 per acre. 
 
 1460. Grubbing. — Grubbing includes the removing 
 of all trees and stumps lying within the slope stakes in cut- 
 tings and in embankments where the fill is two feet or less. 
 Formerly all trees and stumps were grubbed by digging 
 about the stump and exposing the roots, which were cut off 
 with an ax. After the large roots were severed, a long 
 
RAILROAD CONSTRUCTION. 877 
 
 lever was used to complete the work by overturning the 
 stump. A better method succeeded this very slow and 
 expensive work of grubbing. The trees were left standing 
 and as soon as the large roots were cut, horsepower was 
 employed as follows: A strong rope was fastened to the 
 trunk high above the ground. A strong team (often two 
 teams) were then hitched to the rope at a safe distance 
 from the tree. The leverage gained was great, and the tree 
 could often be overset with half or even less than half the 
 grubbing that was required by the older process. In mod- 
 ern practice dynamite is almost exclusively employed. The 
 trees are first felled and their trunks and branches removed. 
 A round-pointed bar of steel 2 inches in diameter is driven 
 at an angle beneath the stump, penetrating far enough to 
 bring the explosive directly beneath the stump. The bar is 
 then removed, and the hole loaded with dynamite, precisely 
 as in blasting rock. A little experience will enable one to 
 gauge the amount of the charge. The execution of the 
 powder is thorough, generally blowing the stump, together 
 with the roots, completely out of the ground and splitting 
 the stump into several pieces, which greatly facilitates the 
 work of handling them. In grubbing stumps with dyna- 
 mite, the gain in first cost over other methods is great, but 
 the gain in time is greater still. 
 
 Grubbing is sometimes paid for by the acre, oftener by 
 the stump, and in some cases the cost of grubbing is in- 
 cluded in the price paid for excavation. 
 
 As stated in Art. 1433, the clearing of the right of way 
 will often afford opportunity for slight changes in the line 
 which will considerably reduce the cost of construction. It 
 is important that the work of cross-sectioning be completed 
 at the earliest possible date after construction has com- 
 menced, as the demands upon the engineer's time multiply 
 when construction is well under way. Where the line 
 traverses open and timbered country in about equal propor- 
 tions, the cross-sectioning on the open stretches can be 
 pushed while the clearing is being done; in this manner the 
 work can be kept well in hand. 
 
878 RAILROAD CONSTRUCTION. 
 
 CULVERTS. 
 
 1461. Classification of Culverts. — Culverts are 
 
 of three classes, viz., box, tile, and arched. The dimen- 
 sions of a culvert will depend upon the amount of water to 
 be discharged. This amount will depend upon the area 
 and character of the water shed. The engineer can approxi- 
 mately determine this area either from an inspection of 
 county maps or from personal examination of the country. 
 Local records of high water will be of great service to him. 
 Culverts should always be made large enough to meet the 
 requirements of the greatest freshets. The following for- 
 mula is used by some engineers in determining the area of 
 a culvert opening : 
 
 A=c^^, (102.) 
 
 in which A is the area of the opening of the culvert in 
 square feet, M is the drainage area in acres, and c the vari- 
 able coefficient depending upon the nature of the country, 
 1.6 being used for compact hilly ground, 1 for comparatively 
 level ground, and being raised to 4 for abrupt rocky slopes. 
 For example, under average conditions, a drainage area 
 of 200 acres with a coefficient of 1.6 will give the following 
 cross-section area for a culvert : 
 
 A = l.Gi/200- 22.62 sq. ft. 
 
 In this situation a double-box culvert would be suitable, 
 with openings three feet in width and four feet in height, 
 separated by a wall two feet in thickness. 
 
 1462. Box Culverts. — Foundations will be prepared 
 as follows: Excavate a pit, including the entire area of the 
 opening and the side walls, to a depth of 1 foot. Cover 
 this area with a paving of stones set on edge 1 foot in 
 depth, with a curb two feet in depth at each face of the 
 drain, and start the walls on this paving. The paving, after 
 being laid, should be well rammed, in order to afford a firm 
 foundation for the superstructure. If the fall of the drain 
 does not exceed 9 inches, drop the upper end to a level with 
 the lower end. When the fall is greater than 9 inches, 
 
RAILROAD CONSTRUCTION. 
 
 879 
 
 make a sufficient number 
 of drops of 9 inches each 
 to equal the difference in 
 the elevation of the two 
 ends of the drain. 
 
 At each drop, place a 
 cross-sill 2 feet in depth. 
 Box culverts are not made 
 of greater span than 3 feet. 
 When a wider opening is 
 required, a double-box cul- 
 vert is built with a division 
 wall 2 feet in thickness. 
 
 A general plan for a 
 single-box culvert is shown 
 in Fig. 384. The distance 
 marked 10 ft. is termed 
 the height of the embank- 
 ment at center line. 
 
 Box culverts are gen- 
 erally constructed of dry 
 rubble masonry. The 
 stones in the abutments 
 (also called side walls, and 
 having a height of 3 ft., in 
 Fig. 384) should be of 
 good size, faced with beds 
 roughly dressed and laid 
 with joints well broken. 
 Binders reaching through 
 from face to face of wall 
 must be used in sufficient 
 numbers to insure a com- 
 pact and stable structure. 
 Covering flags (4 ft. 6 in. 
 wide and 1 ft. thick, in 
 Fig. 384) must be of com- 
 pact stone free from seams 
 
 ,20' 121. 
 
 'I2f 
 
 ■t 
 
880 RAILROAD CONSTRUCTION. 
 
 and with faces dressed so as to insure a complete cov- 
 ering. Mortar is used at the discretion of the engineer 
 in charge. The parapet, 1 ft. thick, is laid on the covering 
 flags. 
 
 In soft, marshy soils, a 1-foot paving will not afford a se- 
 cure foundation, especially if quicksand be present. A pit 
 2 feet in depth and filled with stone, leaving only sufficient 
 depth for the 1-foot paving, and well rammed, will, together 
 with the paving, bear any ordinary box culvert. In wet, 
 boggy soils, a secure foundation may be obtained by exca- 
 vating a pit of double the area of the superstructure to the 
 depth of 2 feet and laying a course of logs of uniform size 
 over the entire bottom of the pit. A layer of broken stone 
 is then spread over the logs of sufficient depth to secure a 
 uniformly level surface. The paving is laid upon this 
 surface, and the foundation is then in readiness for the 
 abutments. 
 
 Rule I.— To Lay Out a Box Culvert on the Ground.— 
 Take the height of the top of the parapet from the height ,of 
 the embankment at the center line. With this difference as 
 height of embankme7it, find the side distance as in setting 
 slope stakes. To these side distances add 18 inches, and if the 
 embankment is 10 feet in height or over, add I inch on each 
 end for each foot in height above the parapet. 
 
 The covering flags are 1 foot in thickness and the parapet 
 1 foot in height, making the top of the parapet 2 feet above 
 the top of the abutment or side walls. The height of the 
 parapet is, therefore, the height of side walls -|- 2 feet. The 
 thickness of side walls must never be less than 2 nor more 
 than 4 feet in thickness. 
 
 Rule U. — To Find the Length of Wing Wails. — Add to 
 
 the height of side tea I Is the thickness of the covering fiags. 
 One and a half times this sum plus 2 feet will give the dis- 
 tance from the inside face of the side wall to the end of 
 tving. 
 
 The wing walls (marked 8 ft. long, in Fig. 384) must be 
 parallel to the center line of the road. 
 
RAILROAD CONSTRUCTION. 881 
 
 Example. — The roadway is 16 feet in width, the height of the 
 embankment at the center line is 22 feet, the abutments are 4 feet in 
 height, the covering flags 1 foot thick, the parapet is 1 foot in height ; 
 what is (a) the distance from the center line to end of abutment wall, 
 and (d) the distance from face of abutment wall to end of wing wall ? 
 
 Solution. — (a) Applying rule I, we have 22 — (4 + 2) = 16. 
 16 X H + 8 4- 1 ft. 6 in. + 1 ft. 4 in. = 34 ft. 10 in. Ans. 
 
 ((5) Applying rule II, we have 4 + 1 = 5. 5 X li + 2 = 9ft. 6 in. Ans. 
 
 1463. — Tile Culverts. — In localities where stone is 
 
 scarce and costly, culvert pipe furnishes an economical 
 and efficient substitute. Culvert pipe is made of clay, which 
 is subjected to a high degree of heat, when it is known as 
 vitrified pipe. The manufacture of culvert pipe is carried 
 on extensively in most of the chief American cities, the 
 range in sizes being sufficient to meet all requirements. 
 The pipes vary in length from 24 to 30 inches, and in di- 
 ameter from 12 to 24 inches. They are fitted with socket 
 or bell joints similar to those on cast-iron water pipes. 
 
 The thickness of the shell is -^^ the diameter of the pipe, 
 and the width of the socket ^ the diameter. The pipe is 
 laid on a concrete foundation with sufficient fall to prevent 
 water from standing in the pipes. A shallow pit is dug to 
 receive the concrete, the pipes being laid as soon as the con- 
 crete is in place and brought to a grade. The pipes are 
 laid with joints of cement mortar, and covered with concrete 
 to one-half their height; the latter are held in place by side 
 boards, secured by banking with earth or by stakes driven 
 in the ground. The concrete affords a secure foundation 
 and prevents leaking at the joints, which is the chief cause 
 of failure of pipe culverts with earth foundations. 
 
 The parapet walls are of rubble masonry laid in cement 
 mortar, and carried far enough below the bottom of the 
 pipe to prevent undermining. In alluvial soils, such as are 
 traversed by many of our western lines, it is frequently 
 necessary to carry the parapet walls to a depth of six and 
 even eight feet to guard against the undermfning of the 
 embankment. The parapet walls need not be built until 
 after the completion of the road, when the stone may be 
 
882 
 
 RAILROAD CONSTRUCTION. 
 
 hauled by construction trains, thereby saving the great cost 
 of transporting building stone by teams. A general plan 
 
 C^ 
 
 Wii^H-:.)-] 
 
 :o5 J Ql \^A^- ^^^ 
 
 
 of pipe culvert is given in Fig. 385. When a single pipe is 
 not sufficient to pass all the water, two or more pipes are 
 placed side by side, with concrete well rammed between. 
 
RAILROAD CONSTRUCTION. 883 
 
 1464. Open "Water Culverts. — These are generally 
 of 2 feet span, with walls 2 feet thick, and of not greater 
 depth than 3 feet. The foundation is of 12-inch paving 
 placed as in foundations of box culverts. The walls, 
 directly under the stringers, should be capped with large 
 well-finished stones, so as to afford good bearings for the 
 stringers, and properly distribute the loads of passing trains. 
 Both stringers and cross-ties should be of sawed timber. 
 
 1465. Cattle Guards. — These are placed on each side 
 of a public road crossing when the crossing takes place at 
 grade. Formerly they were built like open culverts, with 
 spans of from 3 to 5 feet and from 3 to 4 feet in depth. The 
 abutment walls, upon which the wooden track stringers 
 were laid, were from 2 to 2^ feet in thickness. The rails 
 were laid directly upon the stringers, thus dispensing with 
 cross-ties and leaving the space between the rails and abut- 
 ments entirely open. Although possible for stock to get 
 into these pits it was almost impossible for them to get out, 
 and they often proved a cause of instead of a protection 
 against accident. 
 
 The modern cattle guard dispenses with both masonry 
 and excavation. It consists of two strips of 3-inch plank 
 laid on cross-ties at a distance apart of 8 feet. Triangular 
 strips of either wood or iron laid parallel to the rails are 
 spiked to these pieces of plank, completely covering the 
 space between the rails excepting space for the wheel flanges. 
 A space 2 feet in width outside the rails is similarly covered, 
 the whole closely resembling a gridiron, which is the name 
 given to this form of cattle guard. It is quickly and cheaply 
 made and thoroughly efficient. 
 
 1466. Open Passage W^ays. — These are passage 
 ways for public roads which cross the railroad below grade. 
 The walls in part serve the purpose of retaining walls, and 
 should have a thickness at their base of about y%- of their 
 height. The coping of the walls is arranged in the form of 
 steps, as shown in the general plan of highway culvert; see 
 Fig. 386. The height A B oi the embankment is 15 feet. 
 
884 
 
 RAILROAD CONSTRUCTION. 
 
 The steps CD, etc., 
 are so arranged that 
 the natural slope E F 
 of the embankment 
 will just touch the 
 back of the steps. 
 The steps are not car- 
 ried down to the level 
 of the ground, but 
 stop at G where the 
 wall has a height be- 
 tween 4 and 5 feet. 
 The section shows the 
 thickness of the walls, 
 which are 2^ feet 
 thick on the line of 
 slope where the steps 
 chow. The thickness 
 at the base is at all 
 points about ^ of 
 the height of the 
 embankment at that 
 point, giving a thick- 
 ness of about G feet 
 where the embank- 
 ment attains its full 
 height, and finishing 
 at the top with a 
 thickness of 2^ feet. 
 The back of the wall 
 is indicated by the 
 line 77 A". The 
 stringer L consists 
 of two timbers 8 
 inches wide by IG 
 inches deep by 17 
 feet in length, sep- 
 arated by cast-iron 
 
RAILROAD CONSTRUCTION. 885 
 
 spools M, and called a packed stringer. The stringers 
 rest on wooden bed-plates N^ N^ 12 inches wide by 3 inches 
 thick, and are notched down 1 inch on the bed-plates. 
 They are spaced 1 ft. 8 in. from the center line of the track, 
 and are held in place by a strut (7, 3 in. by 12 in, by 3 ft. 
 4 in. Stringer bolts P oi \ in. round iron pass through both 
 stringers, one on each side of the strut, and are fastened with 
 nuts fitted with cast washers. The cross-ties (2? 8 in. wide 
 by 7 in. deep, are spaced 18 in. between centers and notched 
 down 1 in. on the stringers. The guard-rail 7? is 7 in. by 
 7 in. bj' 17 ft., and notched down 1 in. on the cross-ties and 
 bolted to every fourth or fifth cross-tie with \ in. bolts. 
 The bridge seat 5 for the stringers is 18 in. deep. The 
 abutments behind the bridge seat are built up to the top of 
 the embankment, thus keeping the earth from falling down 
 upon the bridge seat. The spool M and a device for holding 
 the strut O in position are shown in detail at T. 
 
 In ordinary open culvert masonry the bridge seat and 
 steps are the only dressed stone used in the structure, the 
 body of the walls being built of well-scabbled rubble. Large 
 stones with good beds should compose the bulk of the walls, 
 and when under-sized stones are used they must be 
 thoroughly bonded by large ones. The wall plates should 
 be placed as nearly over the center of the wall as possible, so 
 that the shock and load of the passing train may be equally 
 distributed throughout the abutments. 
 
 1 467. Arched Culverts. — When the volume of water 
 is too great to be discharged by a double-box culvert with 
 openings 3 X 4 feet, an arcbed culvert is substituted with 
 a single opening of the required area. In determining 
 dimensions of culvert openings, the greater danger lies in 
 making them -too small. The volume of surface water 
 discharged from a given area depends on widely differmg 
 conditions, and is often in apparent violation of all pre- 
 scribed rules. It is not within the province of the engineer 
 to attempt to meet phenomenal conditions, but he should 
 meet common extremes, and there is no branch in railroad 
 
886 
 
 RAILROAD CONSTRUCTION. 
 
 construction where he so often blunders as in the matter of 
 culverts. 
 
 1468. Parts of an Arch. — Fig. 387 represents an 
 arched culvert in which the distance D £ is called the span, 
 O F the rise, the lower boundary line D F E the soffit 
 or intrados, the upper boundary G B H the back or 
 extrados. The end of the arch included between the lines 
 
 Fig. 387. 
 
 D F E and G B H is, called the face. Lines level with D 
 and E and at right angles to the face of the arch are called 
 springing lines or springs. The blocks of which the 
 arch is composed are called arcti stones or voussoirs. 
 The center one B F is the keystone, and the lowest ones 
 A and C the springers. The parts B G and B H are the 
 baunclies. The spaces BGNK and B H ML are the 
 spandrels. The material deposited in these spaces is 
 the spandrel fllling. It is sometimes earth and sometimes 
 masonry or partly of both. 
 
 Arches according to their forms have different names. 
 
RAILROAD CONSTRUCTION. 887 
 
 That in Fig. 387 is a semicircular arch, and is the form 
 commonly adopted in culvert building. A circular arch 
 containing an arc of less than 180° is called a segmental 
 arch (see Fig. 388). The arch shown in Fig. 389, composed 
 
 Fig. 388. Fig. 389. 
 
 of three circular arcs, is called either an elliptical or a 
 three-centered arch. 
 
 1469. To Find the Depth of Keystone. — For cut 
 
 stone arches, whether circular or elliptic, find the radius O D, 
 Figs. 387, 388, and 389, which will touch the arch at Z>, F, 
 and^. 
 
 Rule I. — Add together this radius and half the span D E. 
 Take the square root of the sum. Divide this square root by Jf. 
 and add to the quotient -^ of a foot. 
 
 Or, by formula, 
 
 depth of keystone in feet = 
 
 {r^dt^i±M^j^,^foot. (103.) 
 
 For second-class work, increase this depth of keystone about 
 I part; for brickwork or fair rubble, about \ part. 
 
 Example. — The radius (9 D\% 18 feet, the span Z> .£"36 feet; required, 
 the depth of an arch of cut stone for second-class work and for brick- 
 work. 
 
 Solution. — Applying formula 103, we have 
 
 4/18 + 18 
 For cut stone, depth of arch = r +.2 foot = 1.7 feet. Ans. 
 
888 RAILROAD CONSTRUCTION. 
 
 For second-class work, increase depth of cut stone arch | = 1.7 + 
 iX 1.7 = 1.91 feet. Ans. 
 
 For brick or fair rubble, increase depth of cut stone arch ^ = 1.7 + 
 iX 1.7 = 2.12 feet. Ans. 
 
 Rankine's formula for depth of keystone in feet is, 
 
 dcptJi of keystone in feet = \^.1'Z radius. (104.) 
 
 The latter formula may serve where all conditions are 
 theoretically perfect, but, under ordinary conditions, the re- 
 sults given by this formula are too small. The arch stones 
 of a 3G-foot arch should be at least 1 ft. 9 in. in depth, for 
 considerations of appearance as well as security. 
 
 To find the radius O D, Figs. 387, 388, and 389, whether 
 the arch be circular, segmental, or elliptical: 
 
 Rule II. — Square half t/ie span; square the whole rise ; 
 add these squares together and divide the sum by twice the 
 rise. The quotient is the required radius O D. 
 
 Example. — The span is 30 feet; the rise 10 feet; required, the 
 radius O D. 
 
 -, „ ,. 15» + 10' 325 ,«o..* * A 
 Solution. — Radius = -^ — = -^ = 16.25 feet. Ans. 
 
 1470. To Proportion the Abutments for a Stone 
 Arch, whether Circular or Blliptical : 
 
 Rule. — Find the radius O D, Fig. 387, in feet which will 
 touch the arch at D, F, and E. Divide this radius by 5. To 
 the quotieyit, add -^^ of the rise afid 2 feet. The sum ivill be 
 the thickness D N or E M of each abutment at the springing 
 line for any abutment whose height E T does not exceed li^ 
 times its base T U. If of rough rubble, add 6 inches to E M 
 to insure full thickness in every part. 
 
 Or by formula. 
 
 Thickness of abut- 
 ment at spring line in 
 feet, when the height 
 does not exceed 1\ 
 times the base 
 
 radius in feet , rise in feet , ^ ^ , 
 ^ ^^ (106.) 
 
 Mark the points M and A'^ thus obtained. Next, from the 
 
RAILROAD CONSTRUCTION. 881) 
 
 center 6> of the span or chord D E, lay off O F(Fig. 387) 
 equal to ^^ of the span, and join F and V. Through the 
 point J/ draw the line R 6^ parallel to F V, which will mark 
 the back of the abutment E T U M. In the same way, 
 draw the line 5 NX , marking the back of the other abutment. 
 Now on the lines MR and A^ 5 mark the points R and 5, their 
 height above the line M N being half O B, the full height of 
 the arch. Produce the line B O, and upon that line as at P 
 locate a center from which an arc may be described, 
 passing through S, B, and R. This arc will mark the top of 
 the masonry filling above the arch, except when the rise is 
 about \ of the span or less, in which case the masonry back- 
 ing must be carried up solid to the level K L oi the top of 
 the arch. Ordinarily, the height E T oi the abutment will 
 not exceed 1^ times the base T U. Incase the height should 
 exceed E T, a.s E ]', make the base V Z equal to T 6^ in- 
 creased by \ the additional height T Y. Then, from ^ draw 
 a line parallel to U R, which will mark the back line of the 
 abutment. It is a common practice to give to the faces of 
 the abutment a batter of from ^ inch to 1 inch to the foot, 
 shown in the dotted line^ T' V. This considerably in- 
 creases the base of the abutment, and, proportionately, its 
 stability. An arc struck from the center P' with a radius 
 P' R', R' being level with R, will mark the top of the masonry 
 filling above the arch. 
 
 1471. Foundations for Arch. Culverts. — As arch 
 culverts usually require a greater amount of masonry than 
 box culverts, their foundation must be proportionally 
 stronger. The general directions given for box culvert 
 foundations will answer for arch culverts of small span, say 
 from 4 to 8 feet. For greater spans, unless the natural 
 foundation is firm and secure, such as hard clay, sand, gravel, 
 or rock, a deep trench must be dug to receive the founda- 
 tion. If the soil is soft or marshy, it may be necessary to 
 drive piles and cut them off at a uniform elevation below 
 the water-line, and fill between and to the depth of one foot 
 above tops of piles with concrete made with hydraulic cement. 
 
800 
 
 RAILROAD CONSTRUCTION. 
 
 The trench should extend outside the lines of the founda- 
 tion at least 12 inches, in order that the pressure of the 
 superstructure may be sufficiently distributed. The first 
 course of masonry should project at least inches outside 
 the main body of the abutment for the same reason, and 
 should be composed of much larger stones than those which 
 form the main body of the superstructure. The paving be- 
 tween the abutments and curbing at ends of arch should be 
 of the same dimensions as adopted for box culverts. A 
 partial section of arch culvert with concrete foundation is 
 shown in Fig. 390. The stones forming the impost course 
 
 at A, in a culvert of 16 feet span, should be from inches to 
 12 inches thick. 
 
 1472. Concrete. — The concrete for the foundations 
 should be composed of the following ingredients: Cement, 
 1 part; sand, 3 parts; broken stone, 5 parts. If the con- 
 crete is to be deposited below the water level, Portland 
 cement should invariably be used. If the pit is free from 
 water at the time of construction, though ordinarily below 
 water level, Rosendale or any other good American cement 
 may be used. The value of concrete depends much upon 
 the quality of the sand and broken stone used and the man- 
 ner of mixing. Sand containing loam should never be used, 
 
RAILROAD CONSTRUCTION. 891 
 
 and if none other is available, the sand should be washed in 
 a slight current of water, which will remove all the loam. 
 The stone should be broken to a fairly uniform size, and con- 
 tain no piece which will not pass through a 2^-inch ring. 
 If suitable stone is not available, hard-burned brickbats, 
 broken to the requisite size, form an excellent substitute. 
 For mixing concrete a level platform of rough boards is pre- 
 pared, convenient to the foundation pit. A suitable quantity 
 for mixing is the above given proportions in barrels of 
 material, viz., 1 barrel of cement, 2 barrels of sand, and 5 
 barrels of broken stone. The broken stone is deposited in 
 a regular pile, 12 inches in thickness. Upon the same plat- 
 form the sand and cement are mixed in a dry state, after 
 which water is added to them and they are worked into a 
 mortar of uniform consistency. The mortar is then spread 
 evenly over the stones, and the whole mixed with shovels, 
 commencing at the outside of the pile and working towards 
 the middle; which when reached, the shovelers reverse the 
 movement, working towards the outside and casting the con- 
 crete towards the middle, so that when the outside of the 
 pile is reached, the whole will be thoroughly mixed. It is 
 injurious to work the concrete over repeatedly. Twice 
 handling with the shovel, if thoroughly done, is sufficient. 
 The concrete should be deposited in the foundation pit 
 without delay, before setting commences; and with quick 
 setting cements, especially in summer weather, the process 
 is rapid. It is most conveniently handled in wheelbarrows, 
 and can be deposited directly from them into the pit. In 
 marshy situations, it is a common practice to confine the 
 concrete by inclosures of rough boards held together by 
 stakes driven in the ground. As soon as the concrete is de- 
 posited from the barrow, it must be spread with hoes or 
 shovels into uniform layers, the thickness of which will de- 
 pend upon the depth of concrete to be deposited. If only 
 12 inches of concrete, it should be deposited in two layers of 6 
 inches each, and each layer well rammed as soon as deposited. 
 Rammers of about 35 pounds weight, similar to those used 
 in street paving, are recommended. They are of wood 4 
 
892 RAILROAD CONSTRUCTION. 
 
 feet long, G to 8 inches in diameter at foot, with a lifting 
 handle. Ramming, when properlj' done, consolidates the 
 mass of concrete about 5 or 6 per cent., rendering it less 
 porous and increasing its strength. Water collecting upon 
 the surface of the concrete gives evidence of sufficient ram- 
 ming. The surface of the concrete should be brought to a 
 uniform level, and sufficient time be allowed for setting 
 before the abutments are started. 
 
 1473. Mortar. — Cement mortar should be exclusively 
 used in the construction of arch culverts, the cement to be 
 well tested and approved before being allowed to go into the 
 work. Cement which does not show a tensile strength of 
 40 pounds to the square inch after remaining in water 2-t 
 hours should be rejected. The common American cements, 
 if of good quality, mixed in the proportion of 1 part of ce- 
 ment to 2 parts of sand, will afford a mortar suitable for any 
 ordinary engineering structure. Mortar should never be 
 mixed in large quantities, lest its strength be impaired by 
 setting before using. The proper practice is to mix only 
 such quantities as can be used immediately, thus keeping 
 the supply perfectly fresh and insuring the highest results. 
 The cement and sand should always be mixed dry, the water 
 being added afterwards, and the whole thoroughly worked 
 with a hoe before using. 
 
 The use of cheap brands of cement is false economy. 
 Ordinary cement will admit of sand in the proportion of tzuo 
 parts of sand to one of cement. The best Portland cement, 
 especially for work not requiring rapid setting mortar, will 
 bear four parts of sand. Hence, the latter may be used 
 with the same economy as the former, even at twice the cost 
 per barrel. 
 
 1474. Pointing of Joints. — Arch culverts for water- 
 ways are invariably rubble masonry, but of the best of its 
 kind. Sometimes the corner stones of the abutments, as well 
 as the arch stones of the faces, are of cut stone. The joints 
 of these should be left open at the faces until the work is 
 well advanced or completed, when they should be pointed 
 
RAILROAD CONSTRUCTION. 
 
 893 
 
 with mortar made of the best cement in the proportions of 
 1 part of cement to 1 part of sand, and neatly dressed with 
 a pointing tool. The joints of the rubble masonry are 
 simply struck, i. e., the trowel is pressed against the mortar 
 and drawn the full length of the joint, forming a water- 
 shed for each joint. The joints are struck as the stones 
 are laid, the same mortar being used at the faces as in the 
 interior of the walls. 
 
 There are two principal methods used in pointing cut 
 stone, as shown in Figs. 391 and 392. Fig. 391 shows the 
 form in most general use. It is not so ornamental as that 
 
 Fig. 391. Fig. 39~'. 
 
 shown in Fig. 392, but it is less exposed to the weather, and, 
 hence, is more enduring and a more certain protection to 
 the joints. Mortar intended for pointing must be used 
 immediately after mixing, and the pointing tool repeatedly 
 run over the joint or bead, under considerable pressure, in 
 order to compress the mortar and give it a smooth surface 
 and uniform groove or projection. 
 
 1 475. Centers for Arches. — A center is a temporary 
 wooden structure for supporting an arch while it is being 
 built. Centers are built lying flat on a fixed platform, to a 
 full-sized drawing, and vary widely in design, according to 
 the type and dimensions of the arch. The different parts of 
 a center are given in Fig. 393, which is a standard type of 
 centering for all arches of moderate span, say from 6 to 16 feet. 
 
894 
 
 RAILROAD CONSTRUCTION. 
 
 The frames A, A are made of ribs of 1^-inch plank and 
 united as shown in the figure, breaking joints and fastened 
 together with spikes. The ribs are fitted to the drawing as 
 the frames are built. The ribs are 4 ft. 1 in. in length, 8 in. 
 in width at ends, and 10 in. in width at middle, the edge 
 being trimmed down to fit the curve of the arch. The chord 
 B is composed of two planks, each \^ in. thick by 10 in. in 
 width and 1(5 ft. in length, spiked securely to the frames. 
 The upright strut C is 3 in. thick by 10 in. in width, placed 
 
 ' 1 
 
 pr 
 
 1 
 
 
 \ I 
 
 1 
 
 1 
 
 1 
 
 I 
 
 1 
 
 1 I 
 
 1 
 
 
 Ij^ 
 
 1 1 
 
 jCD 
 
 I 
 
 
 directly under the crown of the arch and fastened to the 
 frame by two cleats D securely spiked to both frame and 
 strut. Its foot passes between the planks forming the chord 
 to which it is spiked. The brace E is fastened at top to the 
 strut with spikes. Its foot passes between the chord planks 
 and is shaped to abut against the rib at the spring line, 
 being securely spiked to the chord. The frames are spaced 
 3 feet from center to center, and rest on G in. by G in. caps 
 / which are supported by 6 in. by G in. posts G. These posts 
 rest on 4 in. by G in. ground sills H which rest on the stone 
 paving. On the caps directly under each frame are striking 
 or lowering wedges K, by means of which the frames are 
 raised in case any of the posts should settle. 
 
RAILROAD CONSTRUCTION. 895 
 
 1476. Striking Centers. — Upon the completion of 
 the masonry, the lowering wedges are removed, which per- 
 mits of the removal of the centering. This process is called 
 striking the centers. There is great difference of opinion as 
 to the length of time which should elapse after the comple- 
 tion of the masonry before the centers are struck. In the 
 case of brick and rubble arches where the mortar forms a 
 considerable part of the mass, a period of two or three 
 months should elapse before the centers are struck. This 
 will allow the mortar to harden and prevent undue com- 
 pression of the joints and consequent settlement of the arch. 
 
 1477. General Directions for the Building of an 
 Arch. — All arch stones must be laid with beds in radial 
 lines. The joints at the intrados, or soffit, will, therefore, 
 be thinner than at the extrados, or back. All rough pro- 
 jections must be removed from the beds of the stones, and 
 the stones laid in firm beds with broken joints. Until the 
 arch is half built, the backing need not be started, as an ex- 
 cess of weight on the haunches is liable to cause a lifting of 
 the crown. In arches of large span it is a common practice 
 to load the centering at the crown until 45° of the arch 
 above the springing line is completed. When the 45° line is 
 passed and the pressure on the centering becomes more 
 nearly vertical, the backing must be carried up to take the 
 pressure. The continuance of the centering will be no 
 hindrance to traffic over the bridge. 
 
 1478. Wing Walls. — Wing walls are generally built 
 with faces diverging at an angle of 130° from the face of the 
 arch. Their foundations are prepared at the same time as 
 the abutment foundations, and varied to suit the different 
 heights of wall above them. Abutments and wing walls are 
 carried up together, the stones of both walls interbonding so 
 as to form one solid mass of masonry. The thickness of the 
 wing walls at foundation line should ordinarily be y*g- of the 
 full height of the wall at that point, with faces battered from 
 1 to 1^ inches to the foot and having a thickness of 2^ feet 
 at the top. 
 
896 RAILROAD CONSTRUCTION. 
 
 When y\ of the height of the wall (allowing a batter of 
 1 inch to the foot) does not give a thickness of 2^ feet at 
 the top, the thickness of foundation must be sufficiently in- 
 creased to insure that thickness at the top. Where wing 
 walls attain a height of 12 feet and over, make the thickness 
 of the foundation ^ of the height. Sometimes the slope of 
 the back of the wall is broken up into steps instead of being 
 uniform. Some advantage is gained from such treatment, 
 as the weight of the back filling bears directly upon the pro- 
 jecting stones. Any attempt to give the back a smooth, 
 uniform slope should be avoided. It adds nothing to the 
 appearance of the work, as it is covered by the embankment, 
 and lessens the friction of the filling against the back of the 
 wall, which tends to prevent its overturning. It is far 
 better to increase, the size of the stones, allowing their rough 
 edges to project from the rear face. The large stones act 
 as binders for the smaller ones, greatly increasing the sta- 
 bility of the wall, and the projections afford the necessary 
 friction to the filling. A general plan of a semicircular arch 
 culvert, including parapet and wing walls, is given in 
 Fig. 394. 
 
 The span A B is m feet, and the rise CD 8 feet. The 
 
 thickness of arch D £ is found by applying formula 103, 
 
 Art. 1469, 
 
 » / /- F • /- i^ radius 4- half span , ^ ^ , 
 aeptli of keystone tn feet = -^—^ (- . 2. foot. 
 
 ^ ^ . . . ^. . , 4/8 feet -4- 8 feet 
 
 Substitutmg given dimensions, we have — 
 
 4 
 
 .2 foot = 1.2 feet, which is the depth of key given for cut 
 
 stone. As the rule calls for \ greater depth for arches 
 
 of rubble, which is the material supposed to be used in the 
 
 1 2 feet 
 
 arch under consideration, — ^ — = .3 foot; 1.2 + .3 = 1.5 
 
 4 
 
 feet = required depth of keystone. The length of the soffit 
 
 A D F is equal to half the circumference of a circle whose 
 
 diameter is 10 feet. Its length is, therefore, 25.13 feet. 
 
 The number of stones in an arch should always be an odd 
 
 number, which will place the keystone in the center of the 
 
RAILROAD CONSTRUCTION. 
 
 897 
 
 arch and give an equal number of arch stones on both sides 
 of the key. If now we make the thickness of the arch 
 stones 12 inches from center to center of joint on the soffit, 
 the arch will contain 13 such stones on each side of the key 
 and leave 13|- inches for the thickness of the keystone. 
 The height of the abutments F F' we take at 6 feet. The 
 
 thickness F G oi the abutments at spring line we find by 
 applying formula 105, Art. 1470. 
 
 Thickness of abut- " 
 mcnt at spring line in 
 feet, when height of 
 abutment does not ex- 
 ceed 1^ times its base 
 
 Substituting given dimensions, we have thickness of abut- 
 
 8 8 
 jnent at spring line in feet = — -f- — -|- 2 ft. =4.4 feet. 
 
 radius in feet . rise in feet , „ ,. ^ 
 
 = 5-^+ j/-+2A^'. 
 
898 
 
 RAILROAD CONSTRUCTION. 
 
 This thickness of abutment is for first-class masonry. As 
 our structure is of rubble, we add ^ foot to 4.4 feet, which 
 gives 4.9 feet.. We further increase the thickness of the abut- 
 ments to 5.0 feet, which will insure perfect stability without 
 any excess of masonry. We give to the back of the abut- 
 ment wall a batter of 1 inch to the foot, making the thick- 
 ness of the abutments at the ground line X Y 5 feet 6 
 inches. The height of the points L and J/ above the spring 
 line is 4 feet and 9 inches, equal to one-half the full height 
 C £ of the arch. The arc L E M which limits the top of 
 the backing or spandrel filling is struck with the radius 
 W L^ 18 feet 9 inches in length, found by trial. The wing 
 walls O and Pare shown in plan at Q and R. A section of 
 wing wall at 5" 7" is shown in full at U. The top N of the 
 parapet is 1 foot 9 inches above top of arch. The parapet 
 and wing walls have a coping of dressed stone 6 in. in 
 thickness. 
 
 1479. General Directions for Building Rubble 
 Walls. — Small stones, excepting for back filling, should not 
 be used, provided those of suitable size can be had at 
 reasonable cost. Stones of too great size are equally 
 
 objectionable unless they have 
 full beds and reach from face to 
 face of wall. Many rubble walls 
 are built, as shown in Fig. 395, 
 of large stones showing on one 
 face, but extending only a short 
 distance into the wall, while the 
 back and body of the wall are 
 composed of small stones. The 
 back of the wall, having so much 
 greater proportionof mortar than 
 the front, will in high walls settle 
 considerably more than the front, producing cracks in the 
 masonry. The almost total lack of binders is an even 
 greater source of weakness. Such a wall is objectionable in 
 any situation, but when serving as a retaining wall for a 
 
 Fig. 395. 
 
 Fig. 396. 
 
RAILROAD CONSTRUCTION. 
 
 899 
 
 railroad embankment where the back filling is subjected to 
 the constant vibrations caused by passing trains, its ultimate 
 failure is almost certain. 
 
 A full proportion of large stones should show on both 
 front and back and extend well into the wall, binding the 
 wall compactly together, as shown in Fig. 396. 
 
 RETAINING WALLS. 
 
 1480. A retaining wall is one for sustaining the 
 pressure of earth, sand, rock, or any other substance 
 deposited behind it after it is built. The material deposited 
 is called filling or backing. Retaining walls are much 
 used in railroad construction, especially in sections where 
 the natural slope of the ground approaches closely to that 
 
 Fig. 397. 
 
 of the angle of ordinary earth filling, viz., 1^ horizontal to 
 1 vertical. Railway tracks entering towns, especially where 
 they cross or crowd other lines, terminal grounds, etc., 
 invariably require retaining walls. The pressure exerted 
 by the backing will vary greatly, depending upon the slope 
 of the ground behind the wall, the nature of the material 
 composing the backing, and the manner of depositing it; but 
 chiefly depending upon the height of the backing. The 
 usual form of retaining wall is shown in Fig. 397. There is 
 
900 
 
 RAILROAD CONSTRUCTION. 
 
 no invariable rule for determining the dimensions of retain- 
 ing walls, and the rules of various authors differ widely. 
 The following rule by Trautwine is based upon careful 
 experiments and is widely adopted. The back of the 
 wall is vertical, and the foundations not more than 3 ft. 
 deep. 
 
 Rule. — 1 V lie 71 the backing is deposited loosely, being du mped 
 from earts, barrows, etc., zuall of cut stone or first-class large 
 ranged nibble in mortar, base C D equals .35 of the vertical 
 height D B; wall of good common scabbled mortar rubble, or 
 brick, base C D equals .Jf. of the vertical height D B; wall of 
 well-scabbled dry rubble, base C D equals .5 of the vertical 
 height D B. 
 
 When the backing is deposited in layers and well rammed, 
 these dimensions may be somewhat reduced, but there is no 
 fixed rule. In general, the additional cost of spreading and 
 ramming will quite equal the saving in masonry. 
 
 In Fig. 397, the height B B is 6 feet. The wall, supposed 
 to be of dry rubble, has a base of 3 feet 4 inches. The 
 foundation is laid in a trench about 1 foot in depth, with a 
 footing or offset F G 6 inches in width. The face is 
 battered 1 inch to the foot, which gives the wall a more sub- 
 stantial appearance, though clearly adding nothing to its 
 stability. 
 
 Earth and sand are the materials commonly used for 
 backing. When broken stone, 
 gravel, boulders, or clay are 
 to be used, additional weight 
 must be given to the wall. 
 
 By inclining the base A B 
 of the wall (see Fig. 398), the 
 friction of the wall against the 
 foundation is increased and 
 the danger of overturning 
 lessened. As was stated in 
 Art. 1478, the rough bat- 
 tered back of the wall also *''0' 896. 
 
RAILROAD CONSTRUCTION. 
 
 901 
 
 increases the friction of the backing, tending to prevent 
 overturning. The batter of the face should not exceed 1^ 
 inches to the foot. Any increase is liable to catch water 
 running down the face and carry it into the wall. This 
 danger is increased where the joints of the masonry are in- 
 clined backwards, as in Fig. 308. To obviate this danger, 
 the face stones are sometimes laid in mortar. 
 
 1 481 . Guarding Against Frost. — Where deep freez- 
 ing occurs, the back of the wall should be sloped 
 forwards, as shown in Fig. 399 at ad, and smoothly 
 finished to lessen the hold of the frost, which 
 might otherwise displace the masonry. The foot 
 of the slope d should be at the frost line, usually 
 three or four feet below the surface a. 
 
 1482. Bulging. — Where walls are too thin, Fig.399. 
 they usually first manifest their weakness by bulging out- 
 wards at about one-third of their height above the ground, 
 as at a, Fig. 400. This effect is sometimes owing to the 
 
 yielding of fresh mortar, 
 and if not more than \ inch 
 for each foot in thickness 
 of wall at a, it need not 
 cause apprehension. 
 
 Sometimes retaining walls 
 fail on account of the com- 
 pression of the backing, 
 causing settlement and in- 
 creased pressure against the 
 wall. This is especially fre- 
 quent where the backing 
 supports railway tracks car- 
 rying heavy and rapidly 
 moving trains. In design- 
 ing walls for such situa- 
 tions, this heavy additional 
 
 weight must be provided for by additional weight in the 
 
 wall. 
 
 Fig. 400. 
 
902 
 
 RAILROAD CONSTRUCTION. 
 
 1483. Offsetted Back. — Having proportioned a re- 
 taining wall abdc in Fig. 401, by the foregoing rule, we 
 can, by offsetting the back, as shown 
 in the figure, considerably increase its 
 stability without adding to the volume 
 of the masonry. 
 
 The offsets are determined as fol- 
 lows: Through ^', the middle point of 
 the back, draw any line f g. From 
 /"erect the perpendicular ///. Divide 
 g Ji into any even number of parts, in 
 this instance 4, and draw through 
 these points of division lines parallel 
 to/" //. Then divide/// into 1 great- 
 er number of equal parts than gJi, and through these points 
 of division draw lines at right angles to f h, forming the 
 offsets as shown in the figure. By increasing the thickness 
 
 Fig. 401. 
 
 Fig. 402. 
 
 Fig. 403. 
 
 of the wall at the base, the center of gravity is lowered and 
 the stability consequently increased. The backing included 
 by the lines ^/z and /// exerts only vertical pressure against 
 the offsets, which tends greatly to prevent the overturning 
 of the wall. 
 
RAILROAD CONSTRUCTION. 
 
 903 
 
 1484. Surcharged Walls. — When the backing is 
 higher than the top of the wall and slopes upwards from its 
 inner edge a, at the natural slope a b oi 1^ to 1 (see Fig. 
 402), the dimensions given in Art. 1480 will be inadequate 
 for the increased pressure. The following table prepared 
 by Trautwine gives dimensions of walls for all probable 
 heights of backing: 
 
 TABLE 29. 
 
 ^ a 
 ^•g- 
 
 4> 
 C 
 
 o 
 
 u 3. 
 
 
 
 c 
 o 
 
 
 •o" 
 
 8i> 
 
 33 ^ en 
 
 '^ J5 
 
 t^m 
 
 0;0 
 
 
 "JB 
 
 t: m 
 
 O J2 
 
 J3 
 
 O S 03 
 
 n o 
 
 S o 
 
 3 
 
 ® l3 rt 
 
 OO 
 
 ^ o 
 
 3 
 
 Total Height 
 ing as Comp 
 Height of W 
 
 
 
 
 ffi tn x: 
 
 If a 
 
 
 T3 9i 
 
 
 Thick 
 Pari 
 
 ness of \ 
 .8 of Hei 
 
 Vail in 
 ght. 
 
 Thickness of Wall in 
 Parts of Height. 
 
 1.0 
 
 .35 
 
 .40 
 
 .50 
 
 2.0 
 
 .58 
 
 .63 
 
 .73 
 
 1.1 
 
 .42 
 
 .47 
 
 .57 
 
 2.5 
 
 .60 
 
 .65 
 
 .75 
 
 1.2 
 
 .46 
 
 .51 
 
 .61 
 
 3.0 
 
 .62 
 
 .67 
 
 .77 
 
 1.3 
 
 .49 
 
 .54 
 
 .64 
 
 4.0 
 
 .63 
 
 .68 
 
 .78 
 
 1.4 
 
 .51 
 
 .56 
 
 .66 
 
 6.0 
 
 .64 
 
 .69 
 
 .79 
 
 1.5 
 
 .52 
 
 .57 
 
 .67 
 
 9.0 
 
 .65 
 
 .70 
 
 .80 
 
 1.6 
 
 .54 
 
 .59 
 
 .69 
 
 14.0 
 
 .66 
 
 .71 
 
 .81 
 
 1.7 
 
 .55 
 
 .60 
 
 .70 
 
 25.0 
 
 
 
 
 1.8 
 
 .56 
 
 .61 
 
 .71 
 
 or more 
 
 .68 
 
 .73 
 
 .83 
 
 When the slope a b oi the backing starts at the front a 
 of the top of the wall (see Fig. 403), additional thickness is 
 required. The triangle a c d showing section of earth 
 above top of wall exerts only vertical pressure against the 
 top of wall, and, hence, increases its stability. When the 
 backing reaches above the top of the wall, as in Figs. 402 
 and 403, the wall is surcharged. The following table by 
 Poncelet gives thickness of walls surcharged with dry sand 
 from the outer edge a, Fig. 403: 
 
904 
 
 RAILROAD CONSTRUCTION. 
 
 TABLE 30. 
 
 i§^ 
 
 c 
 o 
 
 
 
 0) 
 
 c 
 o 
 
 
 
 *^ ll 
 
 kl 
 
 m & 
 
 ■^ c 
 
 u 
 
 
 ^1 
 
 a 1- 
 
 
 03 "^ tn 
 
 3 t 
 
 
 o h «? 
 
 iJl 
 
 o ^ 
 
 ° rt « 
 
 
 "^ i 
 
 bo o o 
 
 ^ c 
 
 - 
 
 J= 6 L^ 
 
 bo o o 
 
 .2 c 
 
 
 *S O *i 
 
 rt 
 ^ 
 
 
 'v o z. 
 
 
 03 
 
 3^ffi 
 
 Thickness 
 
 of Wall in 
 
 
 Thickness 
 
 of Wall in 
 
 o - 
 
 Parts of 
 
 Height. 
 
 Parts of 
 
 Height. 
 
 1.0 
 
 .350 
 
 .452 
 
 2.0 
 
 .707 
 
 .930 
 
 1.1 
 
 .393 
 
 .498 
 
 2.4 
 
 .762 
 
 1.020 
 
 1.2 
 
 .439 
 
 .548 
 
 3.0 
 
 .811 
 
 1.110 
 
 1.3 
 
 .485 
 
 .604 
 
 4.0 
 
 .852 
 
 1.180 
 
 1.4 
 
 .533 
 
 .665 
 
 6.0 
 
 .883 
 
 1.250 
 
 1.5 
 
 .579 
 
 .726 
 
 11.0 
 
 .909 
 
 1.280 
 
 1.6 
 
 .617 
 
 .778 
 
 21.0 
 
 .922 
 
 1.310 
 
 1.7 
 
 .645 
 
 .824 
 
 31.0 
 
 .926 
 
 1.320 
 
 1.8 
 
 .668 
 
 .847 
 
 Infinite 
 
 .934 
 
 1.340 
 
 1.9 
 
 .690 
 
 .903 
 
 
 
 
 The table is applied as follows : If the height of the 
 backing is 20 feet and the retaining wall 10 feet, the tabular 
 height of backing is given as 2, and the thickness of the re- 
 taining wall, if of cut stone, should be 10 X .707 = 7.07 feet. 
 
 1485. To Prevent Sliding. — ^ retaining ivall may 
 slide from its foundation ivithout losing its vertical position. 
 Where the wall is built on a timber platform or a smooth 
 rock surface, the danger of sliding is great, owing to insuf- 
 ficient friction between the wall and foundation. To pre- 
 vent this, strong projecting beams are built into a timber 
 platform running at right angles to the direction in which 
 the wall would slide, as shown in Fig. 404. On wet clay the 
 friction is about ^ the weight of the wall ; on dry earth, from 
 \ to I, and on sand or gravel, from f to f the weight of the 
 wall. 
 
RAILROAD CONSTRUCTION. 
 
 905 
 
 The friction of masonry on a timber platform is about ^jj 
 of its weight if dry and f- of its weight if wet, i. e., a retain- 
 
 ing wall under the above given conditions will not slide 
 under a pressure of ^, f, f, etc., of its total weight. 
 
 1486. On the Theory of Retaining ^Valls. — Let 
 
 a bdc. Fig. 405, be a retaining wall with battered face and 
 vertical back. The 
 top b e oi the back- 
 ing is level with the 
 top of the wall. 
 Let d e represent 
 the natural slope of 
 the material com- 
 posing the filling, — « g ^ 
 
 viz , 1^ horizontal fig. 405. 
 
 to 1 vertical, which is the average of materials used for back 
 
 filling. 
 
 It is assumed that the wall a b d c\s heavy enough to re- 
 sist sliding along its base, and that it can fail only by over- 
 turning, i. e., rotating about its toe c. Now, if the angle 
 
906 RAILROAD CONSTRUCTION. 
 
 ode between the vertical line o </ drawn from the inner bot- 
 tom edge of the wall and the natural slope d c be divided by 
 the line d f \w\.o two equal angles o d / and / d c, thQ angle 
 o ^/y is called the angle and the line d/the slope of maxi- 
 mum pressure. The triangular prism of earth o d f\s called 
 the prism of maximum pressure because, if considered as a 
 wedge acting against the back of the wall, it would exert a 
 greater pressure against it than would the entire triangle 
 d e oi earth considered as a single wedge. For though the 
 last is more than double the weight of the former, yet it re- 
 ceives much greater support from the underlying earth. It 
 has been proved by experiment that if the triangle of earth 
 d e be divided by any line df into wedges, the wedge that 
 will press most against the wall is that formed when the line 
 ^/divides the angle ode into two equal parts. 
 
 The angle o d /i formed by the vertical o d and the hori- 
 zontal ^f// is 00°. The angle of natural slope /i d e is 33° 
 41'; hence, the angle o d f oi maximum pressure is equal to 
 90° - 33° 41' -^ 2 = 28° 09'. 
 
 In making calculations, only 07ie foot of the length of ivall 
 and of the backing is taken, so that all that is necessary is to 
 take the area of the section of the wall and backing. The 
 material composing the backing is supposed to be perfectly 
 dry and possessing no cohesive power, which is practically 
 true of pure sand. 
 
 If we conceive the wall a b d e. Fig. 405, to be suddenly 
 removed, the triangle b d f oi sand included between the 
 line of maximum pressure df and the vertical back b d oi the 
 wall would slide downwards impelled by a force ;/ P, acting 
 in a direction n Pat right angles to the side b d oi the tri- 
 angle, i. e., at right angles to the vertical back b d oi the 
 wall, its center of force being at /-* distant ^ way between b 
 and d, measured from the bottom of the wall d. The amount 
 of this force is expressed by the following formula: 
 
 Perpendicular _ zveight of triangle cf earth bdfx of . 
 pressure n P ~ vertical depth od ' ^ '' 
 
 This formula not only applies to walls with vertical backs, 
 
Fig. 406. 
 
 RAILROAD CONSTRUCTION. 907 
 
 as in Fig. 405, but to those with inclined backs, as in Fig. 
 406, for inclinations as high as 6 inches horizontal to 1 foot 
 vertical, which is rarely met with and never exceeded. 
 
 1487. Friction Caused by Pressure of Back- 
 ing. — If all the backing material contained between the 
 line of natural slope and 
 the back of the wall were 
 unconfined, it would slide, 
 producing motion, but 
 confined by the retaining 
 wall, the force is converted 
 into pressure of earth 
 against the back of the 
 wall, resisted by \.\\^ fric- 
 tion between the compressed earth and the wall. 
 
 If the wall were to begin to overturn about its toe c 
 (Figs. 405 and 406) as a fulcrum, its back b d would rise, 
 producing friction against the backing. So long as the wall 
 does not move, the friction of the backing acts constantly, 
 and must, therefore, be one of the forces which prevent 
 overturning. We ascertain the amount and effect of this 
 friction as follows: Let a bdc, Fig. 407, be a retaining 
 wall, and let n P represent to some scale the perpendicular 
 pressure against the back of the wall calculated by formula 
 106, 
 
 perpendicular _ iveiglit of triangle b df x of 
 pressure n P ~ vertical depth o d 
 
 Make the angle n P h equal to the angle of wall friction, 
 viz., that at which a plane of masonry must be inclined in 
 order that dry sand and earth may slide freely over it, and 
 taken at 33° 41' with the horizontal. Draw ;/ // perpendicu- 
 lar to n P and complete the parallelogram // h k P. Then, 
 k /'will represent to the same scale the amount of friction 
 against the back of the wall. As the friction acts in the di- 
 rection of the back ^ ^ of the wall, it may be considered as act- 
 ing at any point Poi the line of the back, and we will have two 
 forces, viz., the perpendicular pressure n /*and the friction 
 
908 
 
 RAILROAD CONSTRUCTION. 
 
 k P acting at P. By composition and resolution of forces, 
 the diagonal h P measured to the same scale will give us the 
 amount of their resultant, which is approximately the single 
 
 a X b o e tlicorctical 
 
 force both in 
 amount and di- 
 rection which 
 the wall has to 
 resist. This 
 force includes 
 the wall fric- 
 tion. The force 
 Ji P is always equal to the perpendicular 
 force n P divided by the cosine of the 
 angle of wall friction. The cosine of the 
 angle of wall friction is .832, and the value 
 of the force h P mzy be expressed in the 
 following formula : 
 
 Approximate theoretical pressure h P= 
 iveight of triangle bdfxof 
 vertical height od X .^'i'l ' ' 
 
 When the back of the wall does not incline forwards more 
 than (j inches horizontal to 1 foot vertical, equal to an angle 
 of about 26° 34', the following formula by Trautwine is 
 used, viz. : 
 
 Approximate theoretical pressure Ji P=. 
 weight of triangle bdfx. G43, ( 1 08.) 
 
 which includes friction of earth against the back of the wall. 
 When the back of the wall is offsetted, as in Fig. 401, the 
 direction of the pressure of the earth will be the same as 
 though the wall had the batter/^. 
 
 1488. To Find the Overturning and Resisting 
 Forces. — To find the overturning tendency of the earth pres- 
 sure and the resistance of the wall against being overturned 
 about its toe c, as a fulcrum, see Pig. 407. Find the center 
 of gravity g of the wall, and through g draw the vertical 
 
RAILROAD CONSTRUCTION. 909 
 
 line g i. Produce the line of pressure Ji P, and draw c v at 
 right angles to this line. To any convenient scale, lay off 
 / / equal to the weight of the wall and to the same scale / ;// 
 equal to the pressure // P. Complete the parallelogram 
 / ;// s t. The diagonal / j will be the resultant of the pres- 
 sure and the weight of the wall. The stability of the wall 
 will be the greater as the distance c r, from the toe to the 
 point where the resultant / s cuts the base, increases. To 
 insure stability, c r must be greater than \ c d. 
 
 The pressure h P, if multiplied by its leverage c v, will 
 give the moment of the pressure about c, and the weight of 
 the wall // multiplied by its leverage c r' will give the 
 moment of the wall. The wall is secure against overturn- 
 ing in proportion as its moment exceeds that of the pressure. 
 
 For example, let the height of the wall^;^ d c, in Fig. 407, 
 be 9 ft. ; the thickness at the base c d, 4.5 ft., and at the 
 top a b^l ft., and the batter oi a c be 1 in. to the ft. The 
 triangle of earth b d f has a base b f ^^ 6.57 ft. and altitude 
 d =■ S^ it. Taking the section as 1 foot in thickness, Art. 
 1486, we have the contents equal to 6.57 X 9 -^ 2 = 29.56 
 cu. ft. Assuming the material to weigh 120 lb. per cu. ft., 
 the weight of the triangle b df is 29.50 X 120 = 3,547 lb., 
 ^/= 4.81 ft. 3,547x4.81 = 17,001. 17,001^^^^=1,895.7 
 lb. = the perpendicular pressure n P. Lay off on a line per- 
 pendicular to the back of the wall at P, to a scale of 2,000 lb. 
 = 1 in., 71 P— 1,895.7 h- 2,000 = .948 in., the perpendicular 
 pressure. Draw P h, making the angle « P h=z 33° 41'. 
 Draw n h intersecting h P in // ; then will n h to the same 
 scale equal the friction of the earth against the back of the 
 wall. Completing this parallelogram, n h k P, the diagonal 
 h P= 1.139 in., which, to a scale of 2,000 lb. to the inch, 
 amounts to 2,278 lb., and is the resultant of the pressure 
 and the friction. 
 
 Produce the resultant h P to u. We next find the center 
 of gravity^ of the wall a b d c. The section of the wall is 
 a trapezoid, and the center of gravity g is readily found as 
 follows: Produce the upper base of the section to x, making 
 a X =1 c d ^= 4.5 feet. Produce the lower base in the opposite 
 
910 
 
 RAILROAD CONSTRUCTION. 
 
 direction toj, making ^j = a d = 2 it. Joiner andj. Find 
 the middle points x' and /' of the upper and lower bases of 
 the section. Join these points. The intersection ^ of the 
 lines X y and x' y' is the center of gravity of the trapezoid 
 a b d c. 
 
 The volume of the section of wall a b d c \% readily found. 
 The sum of top and bottom widths = 2.0 + 4.5 = 6.5 ft. 
 6.5^2 = 3.25 ft. 3.25 X 9 = 29.25 cu. ft. 29.25x154 = 
 4,504 lb. (the weight per cubic foot of good mortar rubble 
 
 Fig. 408. 
 
 = 154 lb.) = the weight of the section a b d c. Draw 
 through g a vertical line g /, and lay off in it to a scale of 
 2,000 lb. to the inch from the point /, where the line of 
 gravity intersects the prolongation of the line of pressure 
 // P^ the length / / equal to 4,504 lb., the weight of the wall. 
 Lay off from / on the prolongation of // /*, / in equal to 
 2,278 lb. to the same scale. Complete the parallelogram 
 / VI s t. The diagonal / s represents the resultant of the 
 pressure and of the weight of the wall. The distance c r 
 from the toe c to the intersection of the resultant / s with 
 the base ^ ^ is more than \ of the width of the base, which 
 insures ample stability. 
 
RAILROAD CONSTRUCTION. 911 
 
 1489. Pressure of the Backing on Surcharged 
 Walls. — In Fig. 408, the surcharge of backing m b o slopes 
 from b at its natural slope and attains its maximum pressure 
 where the slope of maximum pressure d k intersects the 
 natural slope b in at/. Any additional height of surcharge 
 does not increase this pressure. If the surcharge slopes 
 from a, as shown by the line a p, or from any point between 
 a and b, then the slope of maximum pressure must be ex- 
 tended intersecting the slope from a in the point k. The 
 prism of maximum pressure will then be d i k. The triangle 
 of earth a b i on the top of the wall exerts no pressure 
 against the back of the wall, but adds to its stability. 
 
 Having found the weight of the triangle b d f, we have, by 
 formula 108, Art. 1487, 
 
 approximate pressure = weight of triangle b d f x .643, 
 
 which includes the pressure of the backing and the friction 
 of the earth against the back of the wall. 
 
 Draw P n perpendicular to the back of the wall and draw 
 h P, making the angle n P h — 33° 41', the angle of wall fric- 
 tion. Then, h P will be the direction of the pressure. The 
 point of application of this pressure will not always be at /*, 
 \ of the height oi b d measured from d, but above P, as at r, 
 where a line drawn from the center of gravity g of the 
 prism of maximum pressure d i k (omitting any earth rest- 
 ing directly upon the top of the wall) and parallel to the 
 line d k oi maximum pressure cuts the back b d oi the wall. 
 The center of pressure P will be at ^ the height of the wall 
 when the sustained earth d b s ox d b f iorms, a complete tri- 
 angle^ one of whose angles is at b, the inner top edge of the 
 wall. For all other surcharges, the point of pressure will 
 be above P. 
 
 1490. General Directions and Precautions. — 
 
 The batter of the face of the wall should not (unless circum- 
 stances require it) be greater than \\ inches to the foot. 
 When the batter is greater, the joints catch more or less of 
 the water running down the face, which is carried into the 
 joints, tending to weaken the mortar. All mortar used in 
 
912 
 
 RAILROAD CONSTRUCTION. 
 
 retaining walls should have some admixture of cement, es- 
 pecially in the lower courses of masonry. Common lime 
 mortar will not set so long as it is kept wet by the moisture 
 which comes from the foundation and the moist earth back- 
 ing. If allowed to remain long in this condition, it becomes 
 worthless. When the batter is considerably greater than 1^ 
 inches to the foot, the water may be excluded from the joints 
 by careful pointing. 
 
 EXCAVATION. 
 
 1491. Earth Work. — Earth work embraces the exca- 
 vation of all earthy material included within the section of 
 the roadway above the grade line and the transporting and 
 depositing of it upon those sections of the roadway below 
 the grade line, forming the embankment. It also includes 
 all excavations for foundations above the water-line, the 
 cutting of ditches, changing of watercourses, and all excava- 
 tion ordinarily required in the formation and protection of 
 the roadway. Those parts of the roadway formed by ex- 
 cavation are called cuts and, according to their various sec- 
 tions, are called through cuts, those in which the entire 
 width of the roadway is in excavation, and side cuts, in 
 which only a part of the roadway is in excavation and a part 
 in embankment. 
 
 Ordinarily the side slopes in excavation are made at an 
 
 FIG. 409. 
 
 inclination of 1 horizontal to 1 vertical, and the side slopes 
 of embankments at an inclination of 1^ horizontal to 1 verti- 
 cal. The slopes for cuts in the alluvial soils of our western 
 
RAILROAD CONSTRUCTION. 
 
 913 
 
 prairies are commonly made 1^ horizontal to 1 vertical, on 
 account of their small resistance to frost and water. Fig. 
 409 represents a section of a through cut, Fig. 410 a com- 
 
 FlG. 410. 
 
 plete section of embankment, and Fig. 411 a side cut, in 
 which part is excavation and part embankment. 
 
 Methods in handling earth vary widely, depending upon 
 the character of material, the situation, the magnitude of 
 
 Fig. 411. 
 
 the work, and very greatly upon the contractor. The sec- 
 tion of roadway shown in Fig. 411 admits of very eco- 
 nomical construction. The material is loosened with the 
 plow or pick, and cast by hand directly from the cut to the 
 adjacent embankment. 
 
 1492. The Use of a Road Machine. — A more ex- 
 peditious and economical practice is to handle the material 
 with a road machine. A road machine of great strength, 
 especially designed for railroad use, is much used for work 
 of this character. The blade of the machine cuts and 
 scrapes the material from the higher points and carries it 
 
914 RAILROAD CONSTRUCTION. 
 
 along, depositing it in the low places. An experienced fore- 
 man, with a good and well-manned machine, can almost 
 complete the work on a side hill line, leaving only a little 
 trimming and ditching to be done by hand. Before using 
 the road machine, the ground is broken with a plow. Earth 
 under favorable conditions can be handled by road machines 
 at from 10 to 12 cents per cubic yard. A plow especially 
 designed for loosening earthy material is called a "railroad 
 plow." It is amply strong enough to stand the draft of 
 
 Fig. 412. 
 three heavy teams, and is an important part of a grading 
 outfit. Fig. 412 shows a good form of a railroad plow. 
 
 1493. Wheel bar ro^w Work. — The transportation of 
 earth by wheelbarrows has of late years been practically 
 abandoned by the more progressive contractors. There are, 
 however, situations where they may be used to advantage. 
 When the haul is short and the work difficult of access to 
 teams, the pick, shovel, and wheelbarrow, on account of their 
 portability, are brought into use. 
 
 It frequently happens, especially after protracted rains, 
 that teams can not be used on account of miring. Under 
 such conditions, the work can be carried on with wheel- 
 barrows. A runway of planks under all circumstances is 
 necessary to secure a firm and even tread for the wheels. 
 
 In wheelbarrow work, each man loads his own wheelbar- 
 row. A sufficient number of pickers must be employed to 
 keep a constant supply of loosened material. The gangway 
 planks must be kept smooth, in order that there may be no 
 impediment to wheeling. A wheelbarrow carries y'y of a 
 cubic yard of ordinary material. The men in wheeling move 
 
RAILROAD CON*STRUCTION. 915 
 
 at the rate of about 200 feet per minute, or 2^ miles per hour, 
 which is equivalent to 100 feet each way per minute, techni- 
 cally called 100 feet of lead. The length of time required in 
 making a round trip from the pit (as the place of excavation 
 is called) to the dump will be as many minutes as there are 
 100 feet of lead; to which must be added 1:^^ minutes for 
 loading and dumping. Delays of various kinds are met with, 
 which will consume about yV of the time; so that in calcu- 
 lating the number of trips which each man will make in a 
 day the total number of minutes in a working day of 10 
 hours, viz., 600 minutes, must be reduced by 60 minutes, 
 leaving 540 minutes for actual work. We will, therefore, 
 have 
 
 the number of trips for each man per day = 
 
 540 
 
 1.25 + the number of 100 feet lengths of lead' 
 
 Example. — Allowing $1.20 per day as wages for men, what will be 
 the cost to the contractor for handling earth with wheelbarrows, the 
 lead being 500 feet ? 
 
 Solution. — The number of trips per day = tj-^^ = = 86.4 trips. 
 
 As 14 trips are required for each cubic yard of material, the number 
 
 of cubic yards handled per day per man = -zrj- = 6.17 cubic yards, and 
 
 the cost per cubic yard to the contractor for loading and wheeling will 
 
 §1.20 
 be -K-ry = 19.45 cents per cubic yard. 
 
 It will require one picker for each 5 wheelbarrows. Five wheel- 
 barrows will handle 6.17x5 = 30.85 cubic yards. Consequently, we 
 must add to the above cost per cubic yard §1.20, the wages of the 
 
 1.20 
 picker, divided by 30.85, the number of yards loosened, = 
 
 3.89 cents. 
 
 In addition to the above items, there must be added the wages of a 
 
 foreman and water carrier, one each for a gang of 30 men, of which 24 
 
 handle wheelbarrows. A foreman will cost $2.50 per day and water 
 
 carrier $1.00 per day, making $3.50 per day. The additional charge 
 
 $3 50 
 against each wheelbarrow will, therefore, be ' = 14.59 cents, and 
 
 this sum divided by the number of cubic yards carried by each wheel- 
 barrow will give amount to be added to each cubic yard for superin- 
 
 14- tSQ cpnts 
 tendence and water carrier, or — " _ = 2.36 cents per eubic yard. 
 
916 RAILROAD CONSTRUCTION. 
 
 Placing the various items of cost in order, we have 
 
 Cost of wheeling 19.45 cents per cu. yd. 
 
 Cost of picking 3.89 cents per cu. yd. 
 
 Cost of foreman and water carrier 2.36 cents per cu. yd. 
 
 Wear of tools and wheelbarrows 50 cent per cu. yd. 
 
 Total cost to contractor 26.20 cents per cu. yd. 
 
 Add 15 per cent, for contractor's profit. . 3.93 cents per cu. yd. 
 
 Cost to R. R. Company 30. 13 cents per cu. yd. 
 
 A contractor can not undertake wheelbarrow work under 
 30 cents per cubic yard, which is much in excess of prices 
 paid for earth excavation for railroad work in 1804-5. If, 
 however, the contractor is enabled through the use of the 
 wheelbarrow to do work which would be difficult to accom- 
 plish without it, its value is at once manifest, and losses which 
 he may suffer on sections requiring wheelbarrow work he 
 can readily make good on sections admitting of more modern 
 methods. 
 
 1494. Cart Work. — The cost of loading, hauling, and 
 dumping material by carts may be calculated in the same 
 way as in calculating cost by wheelbarrows. An ordinary 
 earth cart weighs about ^ ton and will carry on an average 
 ^ cubic yard of the various soils encountered in railroad con- 
 struction, measured in place before being loosened. The 
 material to be excavated is loosened in two ways, viz., by 
 pick and by plow. When picks are used, the cut is taken out 
 complete to grade, commencing where the grade line cuts 
 the surface of the ground and working backwards, the ma- 
 terial being hauled and dumped to form the adjacent em- 
 bankment. The carts are backed up to the breast of the 
 cut (as it is called), and the material loaded with shovels. A 
 shoveler can shovel ^ cubic yard of sandy soil into a cart in 
 about 5 minutes; of loam, in 6 minutes, and of heavy clayey 
 soil, in 7 minutes. By working constantly without any de- 
 lays, he could shovel in a day of 10 hours, or 600 minutes, of 
 light sandy soil, 120 loads; of loam, 100 loads, and of heavy 
 soil, 86 loads. He will, however, lose about y\ of his time 
 through delays in waiting for carts and from other causes. 
 The cost of loading carts is determined as follows: 600, the 
 
RAILROAD CONSTRUCTION. 917 
 
 whole number of minutes in a working day, less 180 minutes 
 lost through delays, leave 420 minutes actually employed in 
 
 work; and — — = 84, the number of cart loads of light sandy 
 
 
 
 420 
 soil which will be a day's work for one shoveler; — - = 70, 
 
 420 
 the number of loads of loam, and — — = 00, the number of 
 
 loads of heavy soil. The cost of shoveling into carts, with 
 
 1.20 
 wages at $1.20 per day, will be, respectively, -^-j— =1.43 
 
 84 
 
 1 20 
 cents per load for sandy soil; -^—- = 1.71 cents per load for 
 
 1 20 
 loam, and -—— = 2 cents per load for heavy soil. As it re- 
 quires 3 loads to make one yard, the cost for shoveling per 
 cubic yard will be 1.43 X 3 = 4.29 cents per cubic yard for 
 sandy soil; 1.71 X 3 == 5.13 cents per cubic yard for loam, 
 and 2x3 = cents per cubic yard for heavy soil. The cost 
 of picking will, of course, be the same as that given in Art. 
 1493 for the wheelbarrow work, viz., 3.89 cents per cubic 
 yard. A horse will haul a cart at the rate of about 2^ miles 
 per hour, equivalent to 200 feet per minute, or 100 feet going 
 and coming per minute, i. e., 1 minute for each 100 feet of 
 lead. Besides the time consumed in going and coming to 
 and from the dump, there is a loss of about 4 minutes to 
 each trip, which time is consumed in loading, turning, and 
 dumping. The number of trips per day for each cart will, 
 therefore, be the number of minutes in a working day divi- 
 ded by 4 plus the number of 100 feet lengths of lead. For 
 example, suppose the lead is 800 feet, we will then have 
 
 number of cart trips per day = = 50 trips. 
 
 •± -\- o 
 
 As 1 cubic yard of material in place, i. e., before being 
 
 loosened, will make 3 cart loads, the number of cubic yards 
 
 transported by each cart per day will be the number of cart 
 
 50 
 loads handled divided by 3. Accordingly, we have — = 
 
 o 
 
918 RAILROAD CONSTRUCTION. 
 
 16.66 cubic yards, a day's work for each cart. With labor 
 at $1.20 per day, the expense of a horse will be about $1.00, 
 the use of cart and harness 25 cents, and as 1 driver at $1.00 
 per day can attend to 4 carts, the total charge against each 
 cart will be 
 
 Horse $1.00 
 
 Cart and harness. . : 25 
 
 Driver . .25 
 
 Total $1.50 
 
 The cost of hauling per cubic yard will, therefore, be the 
 cost of cart divided by the number of cubic yards hauled, 
 
 and we have ^ / = 9 cents per cubic yard. 
 10.60 
 
 A man is constantly employed on the dump to assist in 
 dumping the carts and spreading material in layers, which 
 will cost an average of 1 cent per cubic yard. A gang of 10 
 carts will require 1 foreman at $2.50 per day and water car- 
 rier at $1.00 per day. The cost per cubic yard for superin- 
 tendence and water carrier will, therefore, be $3.50 divided 
 by the total number of cubic yards hauled by 10 carts. Each 
 cart hauls 16.66 cubic yards, and 10 carts will haul 16.66 
 
 X 10 = 166.6 cubic yards and ' ' ^ =2.1 cents per cubic 
 
 160.0 
 
 yard. 
 
 In hauling loam, the amount of the foregoing items of cost 
 per cubic yard will be: 
 
 Loosening 3.89 cents per cubic yard. 
 
 Shoveling 5.13 cents per cubic yard. 
 
 Hauling 9.00 cents per cubic yard. 
 
 Dumping and spreading. 1.00 cent per cubic yard. 
 
 Superintendence 2.10 cents per cubic yard. 
 
 Add for sharpening and 
 
 use of tools 50 cent per cubic yard. 
 
 Total cost to contractor 21.62 cents per cubic yard. 
 
 Add 15 per cent, for con- 
 tractor's profit 3.24 
 
 Cost to R. R. Company 24.86 cents per cubic yard. 
 
RAILROAD CONSTRUCTION. 
 
 919 
 
 The items given are supposed to include repairs of cart 
 roads (a very important matter) and the trimming and 
 ditching of cuts. The cart, like the wheelbarrow, is becom- 
 ing obsolete in modern railroad construction. Its place is 
 being taken by road machines, wheeled scrapers, dump cars, 
 and steam excavators. The pick and shovel are still largely 
 used, especially on the western plains. Hundreds of miles 
 of road are built on the level prairies by casting, that is, by 
 shoveling the material directly from borrow pits at the side 
 of the roadway into the embankment. The soil is generally 
 soft enough to move without the use of a pick, and often for 
 miles the expense of hauling is entirely saved. Under such 
 conditions earth may be handled at from 14 to 16 cents per 
 'cubic yard at fair profit. The embankment on such sections 
 has an average height of about 2 feet. Not an economic in- 
 vestment for the bondholders of the road, but it is often 
 very profitable for those who sell the bonds. 
 
 1495. Wheeled Scraper ^Vork.— The body of the 
 wheeled scraper (see Fig. 413) is of sheet steel about 3^ 
 
 Fig. 413. 
 
 feet square and 15 inches deep, containing about ^ cubic 
 yard when level full. The box is open in front, and can be 
 raised or lowered and revolves on a horizontal axis. All 
 
920 RAILROAD CONSTRUCTION. 
 
 movements of the box are made by means of levers. In load- 
 ing, the box is lowered so that the cutting edge of the open 
 front cuts into the ground. A strong team, and usually a 
 second team called a snatch team, haul the scraper, which fills 
 itself in the same way as an ordinary hand shovel is filled. 
 When full, the box is raised about 1 foot from the ground 
 by means of a lever, and the snatch team is detached. The 
 loaded scraper is then hauled to the dump, the dumping 
 being effected by means of a lever, without stopping the 
 team, which is constantly moving. The wheels have broad 
 tires, which prevent their cutting into the ground. Where 
 wheeled scrapers are used, the material is always loosened 
 with a plow. The cut is not worked from a breast, as with 
 carts, but is taken out in successive layers from the full area 
 of the cut. 
 
 The scrapers are loaded while the teams are moving, and 
 as they are continually in motion, their rate of speed will be 
 somewhat slower than with carts or wagons. Taking the 
 rate of movement of scrapers at 150 feet per minute, the 
 distance traveled in going and coming will be but 75 feet 
 per minute, or 75 feet of lead per minute. Besides the 
 actual length of lead, each team will travel about 25 feet 
 additional in turning and dumping. Hence, the number of 
 trips for each wheeled scraper per day will be the total num- 
 ber of minutes in a working day, viz., GOO divided by the 
 number of 75 feet lengths in the lead -f- 25 feet, and suppo- 
 sing, for example, there is a total lead of 800 feet, the number 
 
 i ^ ■ ' A -11 K 600 600 _ . . . 
 
 of trips per scraper per day will be — — = -— — = 54.54 trips 
 
 oZo 11 
 
 per day, and the number of cubic yards for each scraper 
 
 ^ J. '^ J- 
 
 will be — - — = 27.27 cubic yards per day. 
 z 
 
 It will cost an average of 1 cent per cubic yard to loosen 
 
 soils and 1 cent per cubic yard to load and dump them. An 
 
 additional charge of -^\ cent per 100 feet of lead must be 
 
 made for keeping the road in order. 
 
RAILROAD CONSTRUCTION. 
 
 921 
 
 Spreading, water carrier, and superintendence will cost 
 2 cents per cubic yard. A man and team will cost 13.50, 
 with 50 cents added for snatch team, making 14.00 per day, 
 the charges against each scraper for hauling. We have, 
 
 therefore, the cost of hauling ' = 14.67 cents per cubic 
 
 yard. 
 
 For handling ordinary earthy material with wheeled 
 scrapers, the amount of the foregoing items of cost will be 
 as follows: 
 
 Loosening with the plow 1.00 cent per cubic yard. 
 
 Loading and dumping 1.00 cent per cubic yard. 
 
 Hauling. 14.67 cents per cubic yard. 
 
 Maintaining road at a cost of ^ 
 
 cent for each 100 ft. of lead. . . .80 cent per cubic yard. 
 Superintendence, water carrier, 
 
 and spreading .... 2.00 cents per cubic yard. 
 
 Total cost to contractor. . .19.47 cents per cubic yard. 
 Adding 15^ for contractor's 
 
 profit 2.92 cents per cubic yard. 
 
 Cost to R. R. Company 22.39 cents per cubic yard. 
 
 1496. Drag Scraper W^ork. — The drag scraper 
 
 (see Fig. 414) holds from .15 to .25 of a cubic yard of 
 
 material. The same labor 
 
 of horse and man is required 
 
 for the drag scraper as for 
 
 the wheeled scraper, except- 
 
 ^ ing the snatch team. The 
 
 team will move at the 
 
 same rate, viz., 75 feet of 
 
 lead per minute, but only 
 
 15 feet need be added to 
 
 the lead for dumping and 
 Fig. 414. ^ . T>w 
 
 turnmg. Drag scrapers are 
 
 rarely used for a longer haul than 400 feet. 
 
922 
 
 RAILROAD CONSTRUCTION. 
 
RAILROAD CONSTRUCTION. 923 
 
 The number of trips in a day for a 400-foot lead will, there- 
 
 600 (number of minutes in day) _600_ 600 _ 
 
 ' number of 75 feet length in lead -|- 15 ~~ 415 5.53~ 
 
 108.5 trips at ^ cu. yd. per trip = 21.7 cubic yards, the 
 amount of material hauled by each team per day. As the 
 team and driver cost $3.50 per day, the cost of hauling 
 
 per cubic yard will be -^^t-^ = 16.13 cents. Other charges 
 
 will be the same for drag scrapers as for wheeled scrapers, 
 and we have the items giving total cost to contractor fof 
 delivering material at the dump, as follows: 
 
 Loosening with plow. 1.00 cent per cubic yard. 
 
 Loading and dumping 1.00 cent per cubic yard. 
 
 Hauling 16.13 cents per cubic yard. 
 
 Maintaining road, yVcent for 
 
 each 100 feet of lead. . . .40 cent per cubic yard. 
 
 Superintendence, water car- 
 rier, and spreading. ... 2.00 cents per cubic yard. 
 
 Total cost to contractor, 
 
 exclusive of profit. .... 20.53 cents per cubic yard. 
 Add 15^ for contractor's 
 
 profit 3.08 cents, per cubic yard. 
 
 Total cost to R. R. Com- 
 pany 23.61 cents per cubic yard. 
 
 The above figures are only approximate, and will vary 
 largely with conditions. Much depends upon the material 
 handled, the situation, and the weather; but far more upon 
 the energy, skill, and judgment of the contractor and fore- 
 man. 
 
 1497. Work with a Steam Excavator and Dump 
 Cars. — In cuttings from 8 feet upwards, a steam excavator 
 may be employed to great advantage. A first-class exca- 
 vator, such as is shown in Fig. 415, will excavate and load 
 into dump cars 600 cubic yards per day. 
 
924 RAILROAD CONSTRUCTION. 
 
 The excavator stands on a track a, and as the material 
 ahead of the machine is cut away, the track is extended and 
 the excavator is advanced by means of its own machinery. 
 This is accomplished as follows: The car axles b, b are fitted 
 with sprocket wheels driven by pitch chains c. These 
 chains work on sprocket wheels d^ fixed to the countershaft e. 
 The countershaft carries a pinion, not seen in the drawing, 
 which is driven by the large spur/', which is itself driven by 
 a pinion attached to the main shaft g. The main shaft also 
 carries another pinion which drives the spur //, and the 
 drum attached to its shaft. This drum carries the chains k 
 which give to the crane / its lateral motion. The boom m 
 is formed of heavy steel angles, between which the dipper 
 handle n works. The power for crowding the dipper out- 
 wards is applied through the steel rack and the pinion 
 attached to the dipper shaft, and derived from the hoisting 
 chain q, where it passes over a pocket sheave r. This 
 pocket sheave drives the intermediate shaft s by friction 
 clutch and steel pitched chain. 
 
 The dipper / holds from 1 to If- cubic yards. The teeth 
 are of heavy pointed steel and attached so as to be renew- 
 able. The handle is of oak with racking of heavy cast steel. 
 Steam is generated in the boiler w, and the machinery is 
 driven by the engine v. The reversing levers are shown 
 at w. The excavator crew consists of three men, viz., an 
 engineer, foreman, and craneman. The duty of the latter 
 is to see that the excavator does full work, i. e., that the 
 dipper is filled at each cut of the machine. Six pitmen are 
 required to lay track, see to the shifting of the machine, 
 and help in shifting cars and making up train loads. The 
 bulk of the work connected with the shifting of cars and 
 making up of trains is performed by horsepower. 
 
 A pit foreman takes charge of all work not immediately 
 connected with the working of the excavator. The cost of 
 an excavator is about $6,000. For interest on same and 
 wear and tear of machine, charge 110.00 per day. 
 
 The several items of cost to be charged to the excavator 
 will be the following: 
 
RAILROAD CONSTRUCTION. 925 
 
 Cost of. excavator $10.00 per day. 
 
 1^ tons coal @ 16.00 per ton 9.00 per day. 
 
 Water 4.00 per day. 
 
 Oil, waste, etc 3.00 per day. 
 
 Engineer 4. 50 per day. 
 
 Fireman 2.00 per day. 
 
 Craneman 3.00 per day. 
 
 6 pitmen @ $1.50 9.00 per day. 
 
 Foreman 3.00 per day. 
 
 Horse and driver for shifting cars. . 2.25 per day. 
 
 Total ; $49.75 
 
 At 600 cubic yards per day, the cost per cubic yard for 
 
 $49 75 
 excavating will be ' = 8.29 cents. 
 
 Teams will haul 6 cars holding 1^ cubic yards each and 
 travel at the rate of 3 miles per hour, or an average of about 
 260 feet per minute, which will bean average of 130 feet go- 
 ing and coming, i. e., 130 feet of lead per minute. About 
 3 minutes are consumed in stopping, dumping, and chang- 
 ing team for return to the excavator. It will require about 
 1:^ minutes per car to load, making 9 minutes per train of 
 6 cars. The number of trips per team per day will, there- 
 fore, be equal to 600, the number of minutes in a working 
 day of 10 hours, divided by 9 minutes, the time of loading + 
 3 minutes, the time of unloading + the number of 130 feet 
 lengths of lead. Calculating upon a haul of 1,300 feet equal 
 to ten 130 feet lengths of lead, we have the number of trips 
 
 per team per day = -————— = 27.3. Deducting for de- 
 y — |— o ~j~ j-U 
 
 lays caused by defective track, derailed cars, etc., 3.3 trips, 
 we have 24 trips per day for each team. As each train car- 
 ries 9 cubic yards, the total yardage per team per day is 
 24 X 9 = 216 cubic yards. The team and driver will cost 
 
 $3 75 
 $3.75 per day. The cost for hauling will, therefore, be ' ' 
 
 = 1. 74 cents per cubic yard. Five men are required to main- 
 tain the tracks and take charge of the dump, 4 men at $1.25 
 
926 RAILROAD CONSTRUCTION. 
 
 per day and foreman at $2 per day, making 17.00 per day. 
 The cost per cubic yard for track and dump charges will, 
 
 therefore, be -^— = 1.17 cents per cubic yard. It will re- 
 quire 24 cars to handle the materials, at a cost of 50 cents 
 per car per day, making a total daily charge of $12.00, which, 
 divided by 600, gives an additional charge of 2 cents per 
 cubic yard for use of cars. The total cost to the contractor 
 for excavating, loading, hauling, dumping, and spreading 
 will, therefore, be as follows: 
 
 Excavating and loading 8.29 cents per cubic yard. 
 
 Hauling 1.74 cents per cubic yard. 
 
 Care of track, dumping, and 
 
 spreading 1.17 cents per cubic yard. 
 
 Use of cars 2.00 cents per cubic yard. 
 
 Total cost to contractor 13.20 cents per cubic yard. 
 
 Adding 25;^ for contractor's 
 
 profit 3. 30 cents per cubic yard. 
 
 Cost to R. R. Company 16.50 cents per cubic yard. 
 
 On account of the great cost of plant and heavy contin- 
 gent expenses, the contractor should calculate on a profit of 
 25 per cent, when making estimates on this class of work. 
 
 1498. Rock Excavation. — A cubic yard of hard rock 
 in place, i. e., before being blasted, weighs on an average 
 1.9 long tons, or 4,256 lb., equal to 158 pounds per cubic foot. 
 A cubic yard of hard or solid rock w/irn broken up by blasting 
 so that it may be loaded into carts will occupy about 1.8 cubic 
 yards of space, or 48.6 cubic feet of space. Each cubic foot 
 
 of broken rock will, therefore, weigh ' = 87. 6 lb. A cart 
 
 will carry about -^ of a cubic yard of solid rock, i. e., 9.7 cubic 
 feet of broken rock, which will weigh on an average 850 lb., 
 which is only 50 lb. more than an average cartload of earth. 
 A horse may, therefore, be expected to haul as many loads 
 of broken rock as of earth. It will cost on an average 
 40 cents per cubic yard in place to cover the cost of loosen- 
 
RAILROAD CONSTRUCTION. 927 
 
 ing, including sharpening tools, drilling, powder, etc. It 
 will cost an average of 10 cents per cubic yard in place to 
 load the stone into carts. As the number of cubic yards of 
 rock handled per day is less than the number of cubic yards 
 of earth, the cost of superintendence and of water carrier 
 will be greater, say 3 cents per cubic yard. Repairs of road 
 will cost ^ cent for each 100 feet of lead. Dumping and 
 spreading will cost 2 cents per cubic yard. Carts will cost 
 same as in earth excavation, viz., $1.50 per day. It will 
 require an average of 5 minutes to load and dump carts. 
 
 Example. — For a lead of 600 feet, what will be the cost to the con- 
 tractor for delivering solid rock on the dump ? 
 
 Solution. — The number of cart trips per day will be 600, the 
 number of minutes in a working day, divided by 5 + the num- 
 ber of 100 feet lengths of lead. We have, accordingly, number of 
 
 cart trips per day = ;; ^ = 54.5 trips. At ^ cubic yard per cart, the 
 
 54 5 
 number of cubic yards hauled per cart per day will be —^ = 10.9 
 
 cubic yards in place. The cost of hauling will, therefore, be $1.50, the 
 cost per day per cart, divided by 10.9, the number of cubic yards 
 hauled per cart, which gives 13.76 cents per cubic yard in place, that 
 is, of solid rock. We have then for handling solid rock with carts, 
 the following items of cost, viz. : 
 
 Loosening 40.00 cents per cubic yard. 
 
 Loading 10.00 cents per cubic yard. 
 
 Hauling 13.76 cents per cubic yard. 
 
 Dumping and spreading 2.00 cents per cubic yard. 
 
 Superintendence and water car- 
 rier 3.00 cents per cubic yard. 
 
 Repairs of road 1.20 cents per cubic yard. 
 
 Total cost to contractor 69.96 cents per cubic yard. 
 
 Add 15 per cent, for contractor's 
 
 profit 10.49 cents per cubic yard. 
 
 Cost per cubic yard to the R. R. 
 Company 80.45 cents per cubic yard. 
 
 All stone and detached rock found in separate masses, con- 
 taining not less than 3 cubic feet nor more than 1 cubic yard, 
 and all masses of rock, slate,, or coal, or other rock soft 
 enough to be removed without blasting, are classified as 
 
928 RAILROAD CONSTRUCTION. 
 
 loose rock and may be handled at about half the cost of 
 solid rock. 
 
 1 499. Hand Drilling:. — Hand drilling is performed in 
 two ways, viz., by churn drilling and by Jumping. A 
 
 churn drill is made of a round iron bar about 1^ inches in 
 diameter and from 6 to 8 feet in length, having a piece of 
 tool steel a little wider than the diameter of the bar welded 
 to one end of it. This, after being properly hardened and 
 sharpened, forms the cutting edge. In ordinary work, the 
 holes are from 1^ to 3 inches in diameter and from 2 to 4 feet 
 in depth. Holes drilled with the churn drill are usually 
 vertical. In drilling the bench in tunnel work the drills are 
 inclined slightly backwards from a vertical line. In drilling, 
 the churner raises the drill a few inches, turning it slightly 
 in the hole and allowing it to fall. The drill in a free, hole 
 rebounds so that but little effort is required by the driller 
 in lifting the drill. An experienced driller will in a working 
 day of 10 hours drill from 5 to 12 feet of 2-inch hole, de- 
 pending upon the character of the rock. In granite or hard 
 limestone from 7 to 8 feet of If-inch hole is a fair day's 
 work and from 9 to 10 feet in ordinary sandstone. When 
 the hole is more than -4 feet in depth, two men are put to 
 the drill. 
 
 The Juniper is a short drill which is held and turned by 
 a man in a sitting posture while blows from 8 to 12-lb. ham- 
 mers are delivered upon the head of the drill by two other 
 men called strikers. The average depth of a hole per man 
 is considerably greater with the churn drill than with the 
 jumper. The advantage of the jumper lies in its admitting 
 of drilling holes at any angle and in many places where the 
 churn drill could not be worked on account of limited 
 space. In drilling with jumpers, drills of various lengths 
 are used, depending upon the depth of hole. Drill bits re- 
 quire sharpening at each G to 8 inches of hole. Great skill is 
 required in tempering in order that the drills may do full duty. 
 
 On surface work, good d,rillers are paid from $1.50 to 
 $1.75 per day. In tunnel work from $1.75 to $2.00 per day. 
 
RAILROAD CONSTRUCTION. 929 
 
 1 500. Percussion Drills. — Percussion drills are usu- 
 ally spoken of as rock drills, and are built to be driven by 
 steam, compressed air, or electricity. They should be de- 
 signed for hard service, such as sinking shafts and drilling 
 tunnels in the hardest rock. They should strike a hard 
 blow, and be so built as to stand the most severe usage, yet 
 be readily kept in repair with the facilities available in re- 
 gions remote from machine shops. They must stand up to 
 the work of pounding a hole in the hardest kind of rock at 
 the rate of 150,000 to 200,000 blows a day, with all the 
 shocks and jars which that would mean. The blow should 
 be an uncushioned blow; that is, in steam and compressed 
 air drills, the exhaust, during the forward stroke, should 
 remain open until the blow is struck, and none of the force 
 of the blow should be taken up by a cushion of steam or air 
 in the front end of the cylinder. The bit or drill proper 
 must hit the rock, which is the only proper cushioning, and 
 hit it before the pressure enters the front end. Expansive 
 working of the steam or air in rock drills, as has been at- 
 tempted, is a mistake. It is permissible and advisable in 
 engines where the length of the stroke is fixed and where 
 the weight of the machine is not of very great account, but 
 in a rock drill the object is to get the hardest possible blow 
 f.-om the smallest cylinder and the lightest machine. The 
 smaller and lighter the machine, the less space required for 
 working and the easier handled. The value of a hard blow 
 in hard rock is well known. The average drill runner is 
 not careful to keep his bits sharp, and it is a common sight 
 to see a rock drill pounding away with a bit which has no 
 edge at all. It then becomes a question of pounding the 
 rock to pieces instead of cutting it. 
 
 A hard blow will do this, while a tappet drill, which has 
 the force of the blow materially checked by the early admis- 
 sion of pressure to form a cushion, will run along at a lively 
 speed, but accomplish very little in proportion to power 
 consumed. Another quality a rock drill must have is the 
 power to pull the bit out of the hole as well as to drive it in, 
 and that when the hole is blocky, crooked, or muddy. 
 
930 
 
 RAILROAD CONSTRUCTION. 
 
 The best rock drills on the market are the Ingersoll- 
 Sergeant and the Rand drills, operating by steam or com- 
 pressed air, and the General Electric Co. 's drill, operating 
 by electricity. Fig. 416 is a sectional view of one form of 
 a drill using steam or compressed air, without tripod or 
 column. 
 
 The principal parts are as follows: 1 is the cylinder. At 
 the right hand or "back" end of the cylinder there is a 
 washer 2, and a buffer 3, to receive the piston when it 
 strikes at this end. Immediately behind these are the 
 "rotation washer" 4, and the "rotating ratchet" 5, both 
 inside of the back cylinder head 6. To the left, 7 is the 
 brass "rifle nut," 8 is the "rifle bar," and 9 is the piston. 
 The rifle nut 7 is secured to the piston 9 and slides back 
 
 .17 i» ^ 
 
 Fig. 416. 
 
 and forth with it over the rifle bar 8. This compels a 
 relative rotation between the bar and the piston, but as the 
 piston is very much the heavier, the tendency is that only 
 the bar will rotate. It is controlled, however, by the rota- 
 ting ratchet 5, and allowed to turn only in one direction. 
 The piston, therefore, must turn on its return stroke, and 
 in this way it is made to rotate a little at every blow and so 
 drive the bit to a new place. At the extreme left, 10 is the 
 piston bushing to take the wear off the bit. The key 11 is 
 drawn down by the U bolt 12, and so clamps the bit. The 
 front cylinder head 13 and the gland IJ^ are both in halves. 
 The washer 15 and the buffer 10 ease up the blow when the 
 piston strikes here On top we have the steam chest 17, 
 the steam chest covers 18, valve 19, valve guide 20, valve 
 washers 21, and buffers 22. The "goose neck " ^5 carries 
 
RAILROAD CONSTRUCTION. 
 
 931 
 
 one end of the feed screw, which is driven by the crank 
 25 turned by hand. 
 
 Fig. 417 represents a drill mounted on a tripod and ready 
 for work. The feed-screw A is collared at its upper end to 
 the frame B and is thus prevented 
 from moving longitudinally when 
 revolved by the crank fixed to its 
 top. Its lower end works in a nut 
 fixed to the cylinder, which last 
 moves longitudinally backward as 
 the crank is turned. 
 
 The drilling is begun with a short 
 drill called a starter, the first few 
 blows being lightly given until the 
 hole is fairly started, when the full 
 force of the steam is turned on. 
 As the drill penetrates the rock, 
 the cylinder is fed forward by means 
 of the feed-screw A as far as the 
 shell permits. The steam is then 
 shut off gind the drill withdrawn by reversing the movement 
 of the feed-screw. A longer drill is then substituted and 
 the drilling continued. The cutting edges of the bits are 
 necessarily worn by the drilling and constant rotation in the 
 hole so that the diameter of the bottom of each section of 
 hole is slightly less than that at the top ;. accordingly, at each 
 change of drill, one is selected with a bit from ^ to -^^ 
 inch narrower than the one removed. 
 
 In tunnel driving, the drills used in the heading are 
 usually mounted on columns, similar to that shown in Fig. 
 418. The column A is set in an upright position near the 
 face of the heading, the top B of the column being forced 
 against the roof of the tunnel by the capstan screws C 
 which rest in special castings D on the floor of the heading. 
 It is a common practice to place strong blocks of wood on 
 the head of the column and under the feet of the capstan 
 screws, which prevent the rock supports from becoming 
 loosened by the continued jarring of the column, due to the 
 
 Fig. 417. 
 
932 
 
 RAILROAD CONSTRUCTION. 
 
 working of the drills. The arm E at right angles to the 
 column slides up or down the column by means of the 
 
 collar F^ and may be clamped 
 in any position by the clamp G. 
 The drill is carried on this arm 
 and revolves about it as an axis, 
 thus giving a wide range of 
 action. Usually two drills are 
 mounted on each column. In 
 sinking shafts and driving tun- 
 nels, as well as in mine work, 
 compressed air is used instead of 
 steam, which loses much of its 
 pressure through condensation. 
 The use of compressed air greatly 
 promotes ventilation. Percus- 
 sion drills are tinder a pressure 
 of from 60 to 70 lb. per square 
 inch. In one hour one will drill 
 a hole from 2 to 2i^ inches in 
 diameter and from 4 to 10 feet 
 in depth, depending upon the 
 character of the rock, the position 
 of the strata, and the size of the 
 machine. The cost of drilling 
 will vary from 8 to 20 cents per 
 FIG. 41B lineal foot. 
 
 1501. I>rill-bits are of different shapes, being 
 varied to suit the work to be done. For uniform hard rock, 
 the bit is cross-shaped, with the arms of equal length and at 
 right angles to each other. For seamy rock, the arms of 
 the bits are of equal length, but cross each other X fashion. 
 For soft rock, frequently a bit with a Z-shaped cutting edge 
 is used. 
 
 Fig. 419 shows the usual form of drill-bit, and Fig. 420 the 
 tool for sharpening same. On surface work, a drill is 
 usually worked by one man; in tunnel work, two men are 
 
RAILROAD CONSTRUCTION. 
 
 933 
 
 commonly employed. The man in charge of the drill is 
 called the drill runner and his assistant the helper or tailer. 
 
 II m Three or four men are required 
 I I in moving and placing the larger 
 i ■ drills. 
 
 1502. Air Compressors, — 
 
 As before stated, when percussion 
 drills are used for surface work, 
 they are operated by steam which 
 is usually generated in a portable fig. 420. 
 boiler and conveyed to the drills through iron 
 pipes. The direct connection with the drills is 
 FIG. 419. made by means of steam Jiose. When the work 
 is of great magnitude and confined to a small area, a sta- 
 tionary boiler of adequate size is set up. 
 
 When compressed air is required for working the drills, as 
 in mine or tunnel work, air is forced into a receiver by an 
 
 Fig. 421. 
 
 air compressor and conveyed thence by iron pipes and steam 
 hose to the drills. The receiver is a wrought-iron cylinder, 
 from 2 to 4 feet in diameter and from 5 to 12 feet long. A 
 cut of a light duplex compressor made by the Rand Drill Co. 
 is shown in Fig. 421. It is so made that it can readily be 
 
934 
 
 RAILROAD CONSTRUCTION. 
 
 taken apart and transported on mule-back. A and B are 
 the steam cylinders, and C and D are the air cylinders. E 
 is the air delivery pipe and F the steam pipe. Some of the 
 advantages of the duplex type are the following: Since the 
 cranks are set at right angles, the engine can not get on a 
 dead center. One cylinder can be detached when only half 
 the capacity of the machine is required. The power and 
 resistance being equalized through opposite cylinders, large 
 fly-wheels are not necessary. 
 
 A borizontal air receiver is shown in Fig. 422. The 
 air enters the receiver at A, flows through a series of pipe 
 coils, and discharges through B. Cold water constantly cir- 
 
 FlG. 422. 
 
 culates about these coils, cooling the air and drying it at the 
 same time, the moisture dropping to the bottom of the coils. 
 The glass gauge £ indicates the amount of moisture de- 
 posited. When the gauge indicates too great an accumu- 
 lation of water, it is drained off. The cooling water enters 
 the receiver at C and is discharged at D. The gauge F 
 shows the pressure of the air, and // is a safety valve which 
 regulates the pressure. 
 
RAILROAD CONSTRUCTION. 
 
 (CONTINUED.) 
 
 TUNNEL WORK. 
 
 1503. Tunnels. — The location and construction of 
 tunnels are so intimately connected that it has seemed best 
 to consider them under the head of construction alone. 
 
 When grading requires a cutting to exceed 60 feet, it be- 
 comes expedient to drive a tunnel. Tunnels should, when 
 possible, be driven on straight lines, especially for single- 
 track roads, in order to reduce the danger of collisions. 
 
 1504. Laying Out the Surface Line. — The first 
 work of the engineer in preparing for tunnel work is to lay 
 out the tunnel line on the surface of the ground. If the 
 tunnel line is a tangent, it should be run in by foresights, so 
 far as possible, in order to obviate those errors due to defects 
 in the adjustment of the transit, and the work repeated a 
 sufficient number of times to insure a true line. As a per- 
 fect line is of the utmost importance, great pains should be 
 taken, and considerable expense may be incurred in securing 
 long sights. Special transits, called /wwwr/ transits, of double 
 the weight and power of ordinary instruments, are used in 
 running the lines. Frequently, platforms of either timber 
 or masonry, several feet in height, are erected at the suc- 
 cessive points on the line, their elevation admitting of much 
 longer and clearer sights. The hours of the early morning 
 are the most favorable time for running the test line." The 
 air is then of uniform temperature, and the rays of the sun so 
 low as not to interfere with sights. It is useless to attempt 
 work of this kind when the wind is blowing. A cool, cloudy 
 morning is the best time, and in most situations it may be 
 
93G 
 
 RAILROAD CONSTRUCTION. 
 
 O^ had by watching one's chances. 
 Some engineers prefer to run 
 the surface Hne (if it is one con- 
 tinuous tangent) at night, using 
 plummet lamps for sights. The 
 center line of the Cascade tun- 
 nel, on the Northern Pacific 
 Railroad, was run in this way. 
 The laying, out of the surface 
 line is illustrated in Fig. 423. 
 
 Let E B C G represent the 
 profile of the hill or mountain 
 to be tunneled. Setting up the 
 instrument at A and foresight- 
 ing to E^ a point is set at i?, 
 the highest point on the surface 
 line which can be seen from A. 
 Intermediate points H, P, and 
 
 1 /fare also set ivomA. Moving 
 
 2 the instrument to B, a backsight 
 is taken to A and a second 
 principal point set at C, an in- 
 termediate point being at L. 
 Removing the instrument to C, 
 a backsight is taken to B, an 
 intermediate point set at Q, and 
 a fourth principal p©int-"Bet-«rt- 
 D in the opposite tunnel ap- 
 proach. Intermediate points 
 AT, N, and O are also set from 
 C. This surface line may be 
 from 2,000 to 10,000 feet in 
 length, and yet not have more 
 than half a dozen intermediate 
 points. Frequently the surface 
 is so broken as to require more. 
 The instruments require the 
 most careful and repeated ad- 
 
RAILROAD CONSTRUCTION. 
 
 037 
 
 justments. Mountainous country is especially favorable for 
 making careful adjustments, on account of the long sights 
 which are easily obtained in such localities. Substantial 
 monuments should be set at each of the principal points. A 
 short section of log, cut off square, or a section of sawed tim- 
 ber of equal length, set on end in a pit and bedded in cement 
 mortar rubble, answers this purpose well. The timber should 
 extend three inches above the surface of the ground. 
 
 On each monument two points are set about four inches 
 apart. At one of these points a vertical hole one inch in 
 diameter by six inches in depth is bored to hold the per- 
 
 
 Fig. 424. 
 
 manent target, which is set up at each of the principal points. 
 A monument corresponding with the above description is 
 shown in Fig. 424, and target in Fig. 425. 
 
 The target is made of pine or spruce. The shank which 
 fits the hole in the monument and the target are of one 
 piece. The surface of the target is divided as shown in Fig. 
 425, the inner figures painted either red or black and the 
 outer figures white. The target is set up plumb, the points 
 of the squares of different colors uniting in a vertical line 
 which coincides with the established center line denoted in 
 both figures by the letters C L. Such a target can be readily 
 distinguished with a good instrument at a distance of one 
 mile, and is easily and cheaply made. 
 
938 RAILROAD CONSTRUCTION, 
 
 1505. Measuring the Line. — After the line is estab- 
 lished, it is measured, a work requiring great care and re- 
 peated checking. Either of the following methods may be 
 used to obtain horizontal or true measurement: The first 
 method is by the use of a steel tape, plumb-bobs, and spring 
 balance, in which the tape is held in a horizontal position 
 and strained to the same tension at each measurement, the 
 strain being measured by a spring balance. There will be, 
 of course, no uniformity in the length of the sections of line 
 measured, the varying lengths depending mainly upon the 
 degree of the slope. Before the measuring is commenced, 
 stakes are firmly set on line at such distances apart as will 
 permit easy plumbing. A 100-foot standard tape is used, 
 unless the sections are very short, when a 50-foot tape is 
 used. Tacks with small heads are set on line in each stake. 
 In measuring, an allowance of .0000066 part of the length 
 per degree is made for expansion or contraction, according as 
 the temperature at the time of measurement is above or 
 below the normal temperature, which will of course vary 
 in different latitudes. 
 
 Example. — If a temperature of 50° is assumed as normal and at a 
 temperature of 90° a line measures 72.421 feet, what is its normal 
 length ? 
 
 Solution.— 90° - 50° = 40°. 40 x .0000066 (the rate of expansion 
 per degree) = .000264, the amount of expansion for each unit of length 
 of line. The line measures 72.421 feet. The total expansion will, 
 therefore, be .000264 X 72.421 =- .019 ft. 72.421 ft. M-.019 ft. = 72.440, the 
 normal length of the line. 
 
 For measurements of 100 feet or less a tension of 16 pounds 
 is sufficient. This process of measuring is illustrated in 
 Fig. 426. 
 
 The head tapeman holds the zero end of the tape with the 
 spring balance attached at B. 
 
 The hind tapeman, standing at A, holds the tape above 
 the stake until it is in a horizontal position. The tape 
 carries a rider containing a spirit level and a small eye 
 through which the plumb-bob cord is passed. There are 
 two rear tapemen. One holds the tape and gives it the 
 
RAILROAD CONSTRUCTION. 
 
 939 
 
 requisite tension, which is reported by the head tapeman at 
 B\ the other directs the raising or lowering of the tape while 
 bringing it into a horizontal position, adjusts the plumb- 
 
 bob, and reads the tape. The reading is then recorded. 
 The rear tapemen then change places and repeat the work 
 and record the measurements. Each man must read and 
 
 ^ 
 
 ""' '" 
 
 liiiili 
 
 i 
 
 a|iMiliii^iiiiliiii|ft 
 
 ®c 
 
 rliiiTliiiiljiiir \ 
 
 E 
 
 Fig. 427. 
 
 record his measurements independently of the other, in order 
 that they may the better check each other's work. Accord- 
 ingly they do not call out the measurements, but after each 
 
940 RAILROAD CONSTRUCTION. 
 
 has read and recorded his measurements, they compare 
 results, and if there is any considerable discrepancy, the work 
 must be repeated. 
 
 Fig. 427 shows form of tape rider for plumbing tape. It 
 consists of a piece of sheet brass A B, 6 inches in length, an 
 end view being shown at C. It is bent so as to fit closely 
 to the sides and top of the tape when stretched, and slides 
 along the tape. An open slot a d, 2 inches in length, in the 
 side of the rider shows the graduationson the tape. A spirit 
 level D £ is attached to the under side of the rider. To 
 the under side of the bubble tube at its middle point an eye 
 c is attached, from which the plumb-bob /^ is suspended. 
 Directly over this eye and fastened to the rider is a fine 
 point ^, which indicates to the tapemen the precise reading 
 of the tape. 
 
 The second method of measuring is as follows: The 
 stakes are driven as in the first method, and the slope meas- 
 urements from center of tack to center of tack are taken, 
 the spring balance used, and allowance for expansion or 
 contraction made as in the first method. The levels are 
 then taken between the different stakes, the tack in the top of 
 each stake being taken instead of the surface of the ground, 
 and the slope distances are then reduced to horizontal dis- 
 tances. This method is illustrated in Fig. 428. 
 
 The distance a b measured on the slope is 68.10 feet, 
 ^^ = 75.111 feet, ^Trt'^z 57.166 feet. The difference in ele- 
 vation between a and b \% a a' ■= 10.811 ; between b and c is 
 (^(^' = 20.42 feet; between c and d is rr' = 20.752 feet. 
 aa' b forms a right-angled triangle, right angled at a\ in 
 which the hypotenuse is the slope distance, 68.10 feet, and 
 the altitude a a' is the difference in elevation between a 
 and ^=16.811 feet. From the trigonometrical formula 
 
 side opposite , ■ u < 16.811 nAaop 
 
 sm = -, i-5- , we have sm a o a =^ —r;7r^r- = .24686, 
 
 hypotenuse 08.1 
 
 whence angle a ba' = 14° 17'. The base a' b, which is the 
 horizontal distance between a and b, is obtained by apply- 
 ing the formula tan a b a' = -^ f^ . Substituting 
 
 side adjacent 
 
RAILROAD CONSTRUCTION. 
 
 941 
 
 known 
 
 have tan 14° 17' = 
 
 quantities, we 
 10.811 
 
 .16.811 
 
 a' b 
 1G.811 
 
 whence a! b — ,..,.^ 
 
 6G. 032 feet. By a similar 
 process we determine the 
 length of b' c, and find 
 that it equals 72.242 feet, 
 and that c' d = 53.272 
 feet. The total horizon- 
 tal distance between a 
 and d is the sum of 
 a' b-{-b'c-\-c'd = 191.54:6 
 feet. This method of 
 measurement is possible 
 where the slopes are so 
 abrupt as to render the ^ 1 
 use of the plumb-bob P J$ 
 practically impossible. ^ ^ 
 
 1506. Stationing. 
 
 — Stations are estab- 
 lished at each 50 feet, and 
 if the surface be very 
 rough, at each 25 feet, in 
 order that a correct pro- 
 file of the surface may be 
 obtained. 
 
 1507. Curved Tun- 
 nel Lines. — When the 
 tunnel line is curved, the 
 tangents are made to 
 intersect, if possible, and 
 the angle of intersection 
 is measured with the 
 
942 
 
 RAILROAD CONSTRUCTION. 
 
 transit. The tangent distances are calculated and the P. C. 
 and P. T. located by direct measurement. The work and 
 calculations are repeated many times, and every possible 
 precaution taken to secure perfect accuracy of results. 
 
 Orad&H-0. 75 
 
 Fig. 430. 
 
 The sketch given in Fig. 429 shows the difficulties attending 
 the laying out of the Rockport tunnel on the Lehigh Valley 
 Railroad. • 
 
 The original line A B C D followed the course of the 
 Lehigh river, which hugs the bluff E. The tunnel line 
 A F G H \iov\di have been adopted and the tunnel driven 
 when the road was first constructed, but a rival line was 
 building on the opposite side of the river, and there was a 
 
RAILROAD CONSTRUCTION. 943 
 
 race to reach the Wyoming Valley coal fields and command 
 the coal traffic. The tunnel line was accordingly postponed 
 and the river line adopted. After a lapse of twenty years 
 the tunnel was driven in 1882-3. The neck F G through 
 which the tunnel passes (a profile of which is shown in Fig. 
 430) reached a height of more than 300 feet. The hillsides 
 were so steep that in places a man could hardly stand. The 
 tangent K F \s the prolongation of the original tangent A K. 
 The grade of the original line was about 20 feet per mile, 
 and as there was a gain in distance of nearly 1^ miles, there 
 resulted a discrepancy in grades at L of about 30 feet. In 
 order to dispose of this difference, the grade on the old 
 tangent A K and on the tunnel curve was increased to 
 40 feet per mile. In place of the original tangent L D, the 
 tangent G H was substituted, and z.'a G H has a grade of 
 40 feet per mile against L D oi 20 feet, it will be seen that 
 the two grade lines constantly approach each other. The 
 difference in grade being 30 feet, it required, at a gain in 
 grade of 20 feet per mile, a distance of 1^ miles for the two 
 grades to meet. The tangents A K and G H being estab- 
 lished, they were produced intersecting at M. The inter- 
 section angle G M N measured 57°. A 5° 18' curve was 
 decided upon, and the tangent distances M F and M G 
 measured by direct measurement, and the P. C. and P. T. 
 set. 
 
 On account of the steepness of the slopes and the height 
 of the hill, much difficulty was experienced in making a 
 satisfactory intersection. Within a distance of 500 feet 
 there was a difference in elevation of more than 300 feet, and, 
 though taking every precaution, some of the sights contained 
 a vertical angle of more than 60°. The lines were run 
 principally in the early morning hours, though some of the 
 best results were obtained on cloudy days. A large tunnel 
 transit with powerful lenses, and of more than double the 
 weight of an ordinary transit, was used. Common pins 
 against a dark background were used for backsights. First 
 an intersection was made, large plugs (6 inches square) 
 being used. The tangent K M was then repeatedly run, 
 
944 RAILROAD CONSTRUCTION. 
 
 and each line marked on the plugs O and P, Fig. 431, with 
 tacks, each one of which was numbered, as shown in the 
 figure. The lines varied each time, no two coinciding. 
 One or two fell wide of the mark and were ignored. Finally 
 the mean of the lines (as shown by the heavy line in the 
 figure) was adopted as final. The tangent G M was then 
 
 Fig. 431. Fig. 43a. 
 
 run an equal number of times, and each intersection on the 
 line O' P' , Fig. 432, marked on the plug Q' with a tack and 
 numbered. The mean of these intersections, as indicated 
 by the heavy line, was taken as final. 
 
 Equally great difficulty was experienced in locating the 
 P. C. and P. T. The distance was measured many times, 
 and each distance marked. The mean was then taken as 
 the correct measurement. The top of the hill had the form 
 of a plateau, and the center of the curve, O, was located by 
 turning a right angle to the tangent A' F at .F, the P. C, 
 and measuring the radius 1,081.44 feet, locating the center 
 O. The central angle F O G oi 57° was then turned, and 
 the second radius O G run out and measured. The line and 
 measurement falling on the plug at the P. T. at G proved 
 the work correct. The reward for all this care and pains 
 was in the almost perfect alinement of the tunnel. The 
 tunnel was driven from both ends, and when the headings 
 met there was found to be less than a half inch discrepancy 
 in the two lines. 
 
 1508. Tunnel Sections. — Tunnel sections vary 
 somewhat, according to the material to be excavated, but 
 the general form and dimensions are much the same. 
 
RAILROAD CONSTRUCTION. 
 
 945 
 
 The general dimensions are as follows : For double track 
 from 22 to 27 feet wide and from 21 to 24 feet high, and 
 
 Section of Double Track Ttinnel. 
 
 Section of Sin-^'.r Trn-'k Tunnel. 
 
 Fig. 433. 
 
 Fig. 4.34. 
 
 for single track from 14 to 10 feet wide and from 17 to 20 
 feet high. See Figs. 4;3o and 434. 
 
 In seamy or rotten rock the section is sufficiently enlarged 
 to receive a lining of substantial rubble or brick masonry 
 laid in good cement mortar. When the material has not 
 sufficient consistency to sustain itself until the masonry 
 lining is built, resort is had to timbering, which furnishes the 
 necessary support. 
 
 1509. Tunnel Driving. — Tunnels in rock are driven 
 either by hand or machine drills. The requirements of 
 modern railroad construction are such that hand drills play 
 a very important part in tunnel work. There are many 
 points in favor of hand drills and hammers, viz., portability, 
 cheapness, and immunity from the accidents which fre- 
 quently cause delays where machine drills are used. But 
 the process is slow, compared with machine work, and time 
 limitations have made the use of machine drills compulsory. 
 
 1510. Plant. — The plant for furnishing the com- 
 pressed air used in working the drills consists of a boiler 
 house where steam is generated, and an engine house 
 
946 RAILROAD CONSTRUCTION. 
 
 containing the engines, air compressor, and air receiver. Both 
 houses are usually under one roof. If the tunnel is short, a 
 single plant, situated near one of the tunnel portals, furnishes 
 power for all the machinery used at both working faces. 
 When the tunnel is of great length, an air compressing plant 
 is stationed at both ends. About 12 horsepower is required 
 to run each drill (drill cylinders 3i to 3^ inches in diameter), 
 and as each tunnel face requires six drills, a 70-horsepower 
 boiler and engine is required to work each tunnel face. 
 When the air is conveyed a great distance, there is some 
 loss of power through friction. A three-inch pipe will carry 
 sufficient air for six drills. The pipe couplings are well leaded 
 to prevent waste of air. 
 
 1511. Method of Driving. — When the material is 
 rock, the mode of driving is the following : The tunnel sec- 
 tion is divided into two parts, viz., the heading and the 
 bench. The heading comprises from one-fifth to one-fourth 
 of the entire section extending from the roof downward. It 
 is from G to 8 feet in height, and is kept from 50 to 250 feet 
 in advance of the remainder of the section, which is the 
 bench. The drills working in the heading are mounted 
 upon columns, two drills on each column. The drills work- 
 ing on the bench are mounted upon tripods. The air pipe 
 is carried to within about 50 feet of the bench, where a bench 
 hose of equal diameter is attached to the air pipe, lead- 
 ing directly to the bench. At the end of the hose is a metal 
 nozzle called a manifold, containing hose connections for 
 each of the drills. 
 
 A section of heading showing arrangement of drill holes 
 in the face is given in Fig. 435. The two middle rows of 
 holes A B and CD converge at an angle of about 20°, 
 nearly meeting on the center line E F oi the tunnel, and are 
 called the center cut holes. The mass of rock included 
 by these holes is wedge-shaped and shown in plan at A in 
 Fig. 43G. The removing of this wedge by blasting i«j called 
 breaking the cut. Fig. 437 shows a longitudinal section 
 through the center cut holes. The rows of holes G, H, A', 
 
RAILROAD CONSTRUCTION. 
 
 947 
 
 and Z, Fig. 435, on each side of the center cut holes, are 
 called side rounds. If but one row on each side, they are 
 
 Fig. 435. 
 
 Fig. 437. 
 
 Fig. 436. 
 
 Pig. 438. 
 
 called single side rounds ; if two rows, double side 
 rounds. A longitudinal section through the side holes is 
 
 Fig. 439. 
 
 Fig. 440. 
 
 Fig. 441. 
 
 FlO.442. 
 
 given in Fig. 438. The cut and side rounds are loaded at 
 the same time. 'I^he cut is fired first (see Fig. 439), followed 
 
948 
 
 RAILROAD CONSTRUCTION. 
 
 by the side rounds, which are fired either single, i.e., one 
 row on each side of the cut (see Figs. 440 and 441), or 
 double fired, i. e., both rows fired simultaneously, as shown 
 in Fig. 442. 
 
 1512. Enlarging the Heading. — In that portion of 
 the heading shown in the preceding figures, the holes are 
 drilled directly into the face of the heading. After the 
 holes are fired and the material removed, side holes are 
 
 Fig. 444. 
 
 Fig. 445. 
 
 drilled at an angle of about 60° with the center line denoted 
 by the letters C. Z., as shown in section in Fig. 443 and* 
 plan in Fig. 444. 
 
 1513- Removing the Bench. — The bench is taken 
 out in two sections, B and />', as shown in section in Fig. 
 445. The full tunnel section is shown by dotted lines. 
 
 The holes in the bench are inclined backward from a ver- 
 tical line. A longitudinal section through the center line, 
 showing the usual mode of drilling headings and benches, is 
 given in Fig. 440. The center cut holes in the heading // 
 and all the bench holes at B and B' are usually fired 
 
RAILROAD CONSTRUCTION. 949 
 
 together, followed by double side rounds in the heading. 
 The center cut offers the greatest resistance to blasting. 
 The holes are consequently loaded with more powerful 
 explosives than are used for either side rounds or bench. 
 
 In driving the New York aqueduct tunnel, the cut was 
 loaded with dynamite containing from GO to 80 per cent, of 
 hitro-glycerine, while the average bench powder contained 
 but 40 per cent, of nitro-glycerine. On some sections, 
 where rock of special hardness was encountered, the cut 
 was loaded with pure nitro-glycerine. This operation is 
 
 .^;^-.^-~^^ 
 
 Fig. 446. 
 
 always attended with great danger. After several prema- 
 ture explosions, resulting in considerable loss of life, the use 
 of pure nitro-glycerine was abandoned. The effect of firing 
 the cut is generally to pulverize the rock, and all tunnel 
 blasting is intended to so break the rock as to render the use 
 of the sledge-hammer unnecessary in reducing masses of 
 rock to sizes convenient for loading. 
 
 The execution of the powder depends largely upon the 
 judgment used in locating the holes and the angle at which 
 they are bored. The position of the machine while drilling 
 holes at foot of the bench is shown at C, Fig. 446. 
 
950 RAILROAD CONSTRUCTION. 
 
 1514. Drainage. — The grade of a tunnel must be 
 established with reference to securing complete drainage. 
 When the grade at both portals is the same, the grade of the 
 tunnel is made to ascend from both ends, the grades being 
 united by a flat vertical curve. The grade of the St. Goth- 
 ard tunnel is 0.1 per cent. ; that of Mt. Cenis 0.05 per cent., 
 but these grades are very light. A grade of 0.25 per cent, 
 will insure complete drainage and need not be exceeded. If 
 the tunnel is short, a continuous grade may be employed. 
 In such a case, if the tunnel is driven from both ends, it will 
 be necessary to remove the water from the descending por- 
 tion by pumping. In tunnels of considerable length, the 
 grade is usually made to ascend from both ends. This pro- 
 vides complete drainage during construction and also i educes 
 the cost of removing the excavated material, as the loaded 
 cars will either run of themselves or with small draft. 
 When shafts are sunk, the water is removed frorn the tunnel 
 by pumping. 
 
 1515. Shafting. — When the tunnel is of considerable 
 length, and dispatch in driving is of great importance, ad- 
 ditional working faces are obtained by sinking one or more 
 shafts, each shaft affording two additional working faces. 
 Shafting adds very considerably to ^the cost of tunnel dri- 
 ving; for, besides the cost of sinking the shaft, there is the 
 constant expense of hoisting the excava:ed material to the 
 surface, to which must be added the expense of pumping. 
 On the New York aqueduct tunnel, which has a total length 
 of about 33 miles, a shaft was sunk at each interval of one 
 mile, the shafts varying in depth from 80 to 380 feet. Where 
 shafts are employed, the greatest care and skill are neces- 
 sary in transferring the alinement from the surface of the 
 ground to the tvmnel at the foot of the shaft. 
 
 1516. Shaft Lining. — When the shaft is sunk through 
 solid rock, the walls are self sustaining, and no timber lining is 
 required except a curb at the top of the shaft. If, however, 
 the material is earth, loose rock, or shale, the shaft must be 
 timbered. The timbers are put in place as the shaft is sunk. 
 
RAILROAD CONSTRUCTION. 
 
 951 
 
 Frames {se/s, they are commonly called) of timber, shown 
 at A in Fig. 447, are placed about 4 feet apart, and behind 
 these frames, lagging^, of either sawed timber or half round 
 poles split from young trees, is placed on end and in close 
 contact. As each frame is placed in position it is supported 
 by struts footing on the bottom of the shaft, or if the walls 
 are sufficiently firm, the frames are held in place by wedges, 
 
 Fig. 447. 
 
 until another set is required, when timber struts C, mortised 
 into the frames, form the permanent support. These struts 
 are placed one above the other, and, together with the 
 frames into which they are mortised, form continuous tim- 
 ber columns extending from the bottom to the top of the 
 shaft. With each set of timbers a horizontal timber D, 
 called a bunton, is placed with ends abutting against the 
 
952 RAILROAD CONSTRUCTION. 
 
 vertical timber E. A beveled seat with a square shoulder 
 is cut on the vertical timber for each bunton. The buntons 
 are held in place by wedges shown at /^and F' . These 
 wedges are forced between the bunton and the shoulder of 
 the beveled seat. As the wedges are tightened, the bunton 
 is forced downwards until it is perfectly rigid. Vertical tim- 
 bers 6", G' are spiked to the buntons and to the ends of the 
 frames, to serve as guides for the carriage. A detail of the 
 splice of the carriage guide is shown at H and of the wedges 
 at K. As all shafts are moist, and many decidedly wet, 
 iron should only be used in timbering when no substitute 
 can be found. The pressure of earth or loose rock against 
 the timbers is usually sufficient to hold them in place, and 
 most of the joints do not require keying. Treenails 
 (wooden pins) should be used in place of iron. The lagging 
 must be put in place as fast as the work progresses, and all 
 spaces behind it filled with welUrammed earth. In very 
 wet ground or in quicksand, special devices are employed 
 to meet the needs of the situation. Shaft sinking in bad 
 ground is exceedingly dangerous work, and every known 
 precaution is essential if loss of life would be avoided. 
 
 1517. Removing Excavated Material. — The ma- 
 terial excavated in tunnel driving is called muck. The 
 muck is loaded into dump cars at the foot of the bench, 
 which, when there is a sufficient descending grade, run by 
 gravity either to the foot of the shaft, where they are hoisted 
 to the surface, or to the dump outside the tunnel. When 
 there is not sufficient grade to run the cars of themselves, 
 mules are employed to haul them. 
 
 A single track A^ Fig. 448 (ordinarily of 3 feet gauge), is 
 laid on the center line of the tunnel, with passing branches 
 at suitable intervals. At a distance of about 100 feet from 
 the bench a simple switch is built, and two tracks C and D 
 laid to the bench, which permit the loading of two cars at 
 the same time, and provide for shifting cars. On a level 
 with the top of the bench, and directly over the cars, a scaf- 
 fold E is erected, and upon it a runway of planks F is laid. 
 
RAILROAD CONSTRUCTION. 
 
 953 
 
 extending from the scaffold to the heading. The heading 
 muck is loaded into barrows and wheeled on this runway to 
 the scaffold, and emptied directly into the cars. 
 
 A simple and very effective bench scaffold is made of 
 wrought iron pipe supports and shown in Fig. 448. Each 
 support consists of two pieces of pipe, one telescoping within 
 
 v^?^^-*/y///y////riu/////////Znc////^////////)i^////////ZZ'iii,'^//^^^ 
 
 
 ¥^- 
 
 .,-C^.JRsx 
 
 "---■Jiitb ifrajic. -^ 
 
 Fig. 448. 
 
 the Other, and provided with clamps by means of which 
 they are adjusted to any desired length. The plank is laid 
 directly upon these pipe supports. The air for working the 
 drills is carried from the air pipe G to the bench by means 
 of the bench hose //. The manifold K attached to the end 
 of the bench hose contains hose connections for all the drills. 
 A ditch L on the opposite side of tunnel from the air pipe 
 drains the tunnel. 
 
954 
 
 RAILROAD CONSTRUCTION. 
 
 3 5 
 
 As the work advances from the tunnel entrance, or from 
 the foot of the shaft, more time is required to haul away 
 the loaded cars and bring back the 
 empty ones. When one mule is no 
 longer able to perform the work a 
 second one is added, and passing 
 branches are built in the main track 
 at suitable intervals, where returning 
 empty cars are switched while the 
 loaded cars are passing outward. A 
 passing branch contains two switches, 
 which are made self-acting by the 
 following simple device, shown in 
 Fig. 449. The points of the switch 
 rails a and b are connected by a 
 clamp rod, attached to a spring c d, 
 which is constantly acting, and holds 
 the point a close against the main 
 rail c f, and the switch is constantly 
 set for the passing branch k I. The 
 switch points ;;/ and fi of the second 
 switch are kept in place by the spring 
 op, the switch being always set for 
 the main track q r. An outgoing 
 car running in the direction r q finds 
 the switch Y set for the main track. 
 Upon reaching the switch X, the 
 flange of the right-hand wheel, pass- 
 ing between the rail e f and the 
 switch point a, forces the switch 
 point b against the rail s /, and the 
 car passes the switch in safety. A 
 returning empty car finds the switch 
 X set for the passing branch k /, and in passing from the 
 branch to the main track, the flange of the head wheel, in 
 passing between the rail u t and the switch point ;//, forces 
 the switch point n against the main rail c f, and the car 
 passes safely on to the main track. The springs c ^and op 
 
RAILROAD CONSTRUCTION. 955 
 
 are elastic young saplings, kept in place by strong staples 
 driven into the switch ties. 
 
 151S. Care of Track. — A common fault of contract- 
 ors and their employes is neglect of track. Usually poor 
 material is furnished, worn cut and crooked rails, poor 
 fastenings, poor ties, and often no ties, requiring every 
 sort of makeshift. With such material a good track is im- 
 possible, and requires constant tinkering. Derailments are 
 continually occurring, involving costly delays. Tunnel 
 tracks should be built of good material and in a thorough 
 manner. Short rails of varying lengths are required in 
 keeping the track well up to the bench. With proper care 
 of tracks, the cars may be kept within easy shoveling dis- 
 tance of the bench. The foreman in charge of the muckers 
 should keep a small stock of ties and rails constantly on 
 hand, together with the necessary track tools, and do his 
 own track work. 
 
 1519. Keeping Down to Grade. — The invariable 
 tendency in tunnel work is to keep above grade. The prin- 
 cipal cause is the unconscious effort to avoid the water which 
 is constantly accumulating. This tendency can only be 
 avoided by establishing grade stakes at every 25 feet and 
 keeping the excavation on true lines. The holes drilled at 
 the foot of the bench should penetrate a foot below grade, 
 which will insure the removal of the entire section. Much 
 of the muck in the bottom of the tunnel will require severe 
 use of the pick to remove it. Wedges and a heavy sledge 
 are often of great service in this work. 
 
 1520. Timbering. — When the material is rotten rock 
 or earth, the tunnel must be timbered. The timbered sec- 
 tion should be enough larger than the standard section to 
 admit of a masonry lining. When the material is such that 
 the side walls will stand of themselves for a time, hitches 
 A and B are excavated near the springing line and sets of 
 timbers placed as shown in Fig. 450. Iron clamps shown at 
 C and D hold the timbers together while the lagging is 
 
956 
 
 RAILROAD CONSTRUCTION. 
 
 being placed. It is laid over the timbers lengthwise of the 
 tunnel and as close together as possible. • The spaces G, H 
 
 [Fig. 150. 
 
 between the lagging and the roof are filled with dry rubble 
 or cordwood. 
 
 Roof timbers should be either 12 in. X 12 in. or 12 in. 
 X 14 in. in cross-section, and placed with 2 to 4 feet clear 
 space between each set. Where the ground is very soft 
 with a tendency to expand, larger timbers may be necessary. 
 Hemlock, yellow pine, or spruce is commonly used. In 
 special cases, where great pressure is to be resisted, oak is 
 used. When the side walls will not support the roof tim- 
 bers, they are carried on supports arranged as shown in 
 Fig. 451. Four posts A, C, D and i), resting on sills O, P, Q 
 and Ry are mortised into the cap E F. 
 
 The roof timbers G, H, AT are clamped together as in Fig. 
 
RAILROAD CONSTRUCTION. 
 
 957 
 
 450, and mortised into the cap at spring line. The pressure 
 against the roof timbers is relieved by the struts Z, J/, N^ U, 
 and V, which transfer the stress to the posts C and D and 
 the cap E F. The dimensions of timber given in the draw- 
 ing are such as are used where the pressure is great; they 
 will meet the requirements of most situations. The lagging 
 may be either sawed timber or split poles, obtained by split- 
 
 FlG. 451. 
 
 ting in half straight grained chestnut or oak saplings. The 
 backing may be either dry rubble or cordwood. The latter 
 is preferable, as it is light, portable, and uniform in shape. 
 The side walls are all of well-scabbled rubble of good-sized 
 stones, even beds, and laid in courses with cement mortar. 
 The impost courses S and T should be of well-cut stone, 
 twelve inches in thickness and of full width of wall. The 
 arch is either' brick or rubble. The caps and roof struts 
 
958 
 
 RAILROAD CONSTRUCTION. 
 
 interfere somewhat with arching. Holes are left in the 
 masonry where these timbers interfere until a section of the 
 arch is complete, when they are removed and the gaps filled 
 with masonry, the joints being thoroughly grouted. All 
 other timbers are left in place. The spaces /f, Z, etc., Fig. 
 450, between the arch and roof timbers, are usually filled 
 with concrete. 
 
 When the material through which the tunnel passes is 
 very soft, with slight coherence, all the energy and skill 
 of engineer and workmen are required to make headway. 
 It is considered the better practice to drive the heading at 
 the bottom of the tunnel instead of the top, as by the time 
 
 
 Fig. 452. 
 
 the heading is driven the ground composing the remainder 
 of the section will have become thoroughly drained, and may 
 be taken out with much greater safety and less expense 
 than with a top heading. The mode of driving a heading 
 through such material is illustrated in Fig. 452, in which 
 A represents a cross-section and B a longitudinal section of 
 the heading, with complete system of timbering. 
 
 A full section of timbers is called a set^ of which the up- 
 right timber C is called the leg; the horizontal timber D the 
 sill, and E the cap or collar. The short boards F, F, which 
 extend from collar to collar, and are in direct contact with 
 the sustained material, are caUed poling- doards. They are 
 sharpened to a cutting edge, and are driven into the face of 
 the heading with sledges, a wedge-shaped block G being 
 
RAILROAD CONSTRUCTION. 959 
 
 placed above them to keep them at a proper angle. The 
 planks H which protect the sides of the heading are termed 
 lagging. The flooring K serves to exclude the liquid mud, 
 which would otherwise be forced from underneath by the 
 external pressure. The horizontal cross timber Z, as well 
 as the longitudinal timbers M and A^, are called struts. The 
 floor O serves as a footing for the workmen while driving 
 the poling boards. 
 
 If the material penetrated is wet enough to run, it is 
 necessary to constantly maintain a bulkhead of planks 
 /*, called face boards, which is held in place by struts Q. As 
 the poling boards are driven forward, the top face board is 
 removed, allowing the released material to flow into the 
 gangway. This forms a cavity in the face of the heading, 
 and immediately another bulkhead is started by placing a 
 face board R in advance of those at /*, with a strut 5 to 
 keep it in place. When the heading is advanced half the 
 length of the poling boards, a new set of timbers is put in 
 place, the collar of which takes the strain from the poling 
 boards, which would otherwise be soon broken by the great 
 pressure above them. 
 
 As the section is enlarged, other timbers are substituted, 
 until the complete section is excavated. The masonry 
 lining should follow immediately. The less important tim- 
 bers may be removed as the masonry advances, and their 
 stresses transferred to it; but the main supports should re- 
 main in place, and the masonry be built around them, and 
 not disturbed until the arch is keyed. They can then be 
 removed with safety, and the vacancies in the masonry 
 carefully filled and grouted. All open spaces between the 
 masonry and the timber should be filled with well-rammed 
 concrete. 
 
 1 521 . Centering. — Tunnel centers are built on much 
 the same plan as those used in arched culverts, a full 
 description of which was given in Arts. 1475 and 1476. 
 
 1522. Portals. — Tunnel portals correspond to the 
 face and wing walls of an arched culvert. Usually some 
 
9G0 RAILROAD CONSTRUCTION. 
 
 regard is paid to architectural effect, the walls being of 
 dressed stone laid in courses. 
 
 1523. Alinement and Levels. — During construc- 
 tion, the alinement and levels must be frequently tested. 
 At least once a week the heading should be carefully 
 centered, and a grade stake set at the foot of the bench. 
 
 In running the center line, plummet lamps are used in- 
 stead of the transit poles used on surface lines. A plummet 
 lamp consists of an oil reservoir of brass of the shape of an 
 ordinary plumb-bob, the stem of which contains the wick. 
 The lamp is suspended by a bail, at the crown of which is 
 an eye for the cord which suspends the lamp. When sus- 
 pended, the cord, the flame of the lamp, and the point of the 
 plumb-bob are in the same vertical line. A man holds the 
 cord against the roof of the heading, moving it right or 
 left until the intersection of the cross wires coincides with 
 the flame of the lamp. A point is then marked on the roof, 
 and a hole accurately drilled by hand to a depth of about 
 three or four inches. A plug of dry pine is then driven 
 into the hole, projecting two inches below the roof. The 
 plug is carefully centered and a screw-eye securely fastened 
 in its center, from which a plummet lamp may be suspended. 
 A piece of copper wire equal in length to the full height of 
 the tunnel is attached at one end to the screw-eye and the 
 other end fastened to the wall of the tunnel. 
 
 When the full section of the tunnel is excavated, a plumb- 
 bob is suspended from the wire, just touching the floor of 
 the tunnel. A hole is drilled at the point, plugged, and 
 centered, as on a surface line. For bench marks, holes are 
 drilled in the tunnel wall about two feet above the floor, 
 and plugs of either wood or iron are firmly driven and 
 allowed to project far enough from the wall to allow the 
 rod to be held upon them in a vertical position. In testing 
 the grade of the roof, the rod is held in an inverted position, 
 the foot of the rod being placed against the roof. In this 
 case the elevation of the roof is obtained by adding the rod- 
 reading to the height of instrument. For example, suppose 
 
RAILROAD CONSTRUCTION. 
 
 961 
 
 the tunnel section is 24 feet in height, the floor grade at 
 say Station 160, is 240.5 feet and the height of the instru- 
 ment, which is standing on the bench, is 259.6 feet, what 
 should the rod read to give roof grade for Station IGO ? The 
 floor grade at Station 160 being 240.5 feet, the roof grade 
 will be 240.5 feet + 24 feet (the height of the tunnel section) 
 which is 264.5 feet. As the height of instrument is 259.6 
 feet, the rod-reading for roof grade will be 264.5 — 259.6 = 
 4.9 feet. A common bulls-eye lantern is used to illuminate 
 the cross hairs, and a small headlight reflector affords the 
 best light for reading the level rod and tape, and for taking 
 notes. 
 
 1524. Measuring Excavation. — Various methods 
 are adapted for checking the dimensions of the tunnel sec- 
 
 Pig. 453. 
 
 tion and measuring up the work. The best device is the 
 following, shown in Fig. 453. A semi-circular protractor 
 A B oi a diameter from 8 to 10 feet, and made of light pine, 
 
962 RAILROAD CONSTRUCTION. 
 
 is set up at right angles to the center line of the tunnel. 
 The diameter A B oi the protractor is brought into a hori- 
 zontal position by means of the spirit level C and placed at 
 any desired height above the floor of the tunnel. A sliding 
 rod D E, one end of which is fastened to the center D of 
 the protractor, measures the distances to the tunnel walls on 
 radial lines. The angles which these lines make with the 
 horizontal are read directly from the protractor. The tun- 
 nel section and the actual working measurements are then 
 platted on cross-section paper, from which the amount of 
 excavation is readily calculated. 
 
 1525. Plumbing Shafts. — When a shaft is sunk to 
 increase the number of working faces, the process by which 
 the center line is transferred from the surface of the ground 
 to the bottom of the shaft is called plumbing the shaft. 
 Fig. 454 illustrates the process. Two pieces of plank C and 
 D are spiked to the shaft timbers where the center line 
 crosses, the edges of the plank projecting over the shaft 
 wall. 
 
 Slots E and E are cut in the plank on the center line. 
 An iron plate with a carefully drilled hole in its center is 
 placed over each slot with the center hole exactly on the 
 center line of the tunnel. Holes are drilled in the corners 
 of the plates for screws, by means of which the plates are 
 fastened to the plank. 
 
 Plumb-bobs weighing from 20 to 30 pounds are suspended 
 by fine steel wire which passes through the eye-hole in the 
 plate. On the shaft bottom a pail of oil is placed directly 
 under each plumb-bob, which is entirely immersed in the 
 oil to check the vibrations. When the plumb-bobs come to 
 rest, the lines which suspend them are exactly in the center 
 line as laid down on the surface of the ground. A transit is 
 set up at / (the tunnel having been driven some distance 
 from the foot of the shaft) and moved until both wires are 
 exactly in the line of sight. A plug is then set on the line 
 at K, after which the instrument is moved to A' and a plug 
 set at /, thus establishing the line. ' 
 
RAILROAD CONSTRUCTION. 
 
 9G3 
 
 1526. Ventilation. — In clear weather, the gases 
 formed by the combustion of the powder used in blasting 
 pass rapidly from the tunnel to the outer air. In heavy 
 weather, and especially when the heading is at a consider- 
 able distance from the portal or shaft, several hours are 
 required to clear the tunnel of powder smoke. Under such 
 
 conditions the question of ventilation becomes an important 
 one. In order that a man may do effective tunnel work, he 
 should have a supply of 100 cubic feet of pure air per min- 
 ute. And as there is an average force of 25 men in each 
 
964 RAILROAD CONSTRUCTION. 
 
 heading, the aggregate supply of pure air per heading should 
 therefore be 2,500 cubic feet per minute. A 70-horsepower 
 compressor will deliver to the drills about 500 cubic feet of 
 free air per minute, and there will still be required for ven- 
 tilation the difference between 2,500 cubic feet and 500 
 cubic feet, which is 2,000 cubic feet per minute. 
 
 Exhaust fans with air pipes leading to the headings 
 should provide the balance of 2,000 cubic feet per minute. 
 A 24-inch air pipe, carrying air at a velocity of about 10 feet 
 per second, will provide the necessary ventilation. The air 
 pipe should reach as near to the bench as may be without 
 injury from blasts. Contractors are invariably negligent in 
 the matter of ventilation, causing much needless suffering 
 to their men and much loss to themselves. Men can not 
 and will not do full work in a tunnel reeking with powder 
 smoke. 
 
 Exhaust fans give much better results than blowers, as 
 they remove the foul air and powder smoke direct from the 
 heading, instead of forcing it out through the shaft or portal, 
 as in the case with blowers. 
 
 1527. Cost of Tunnel Excavation. — The cost of 
 tunnel excavation varies widely, depending principally upon 
 the character of the material excavated. Firm rock of 
 moderate hardness can be removed at from $4.50 to $0.50 
 per cubic yard for the entire tunnel section. The heading 
 will cost about 40 per cent, more than the balance of the 
 section, on account of the limited space for working drills 
 and the greater amount of powder required in blasting. 
 Where unusual obstacles are met, the cost may increase 
 200 per cent, or 300 per cent, over the above figures. 
 Earthy material is easily broken, but the expense and delay 
 in timbering and lining brings the cost to about the same 
 figures as for solid rock. 
 
 1528. A Day's Work for a Machine Drill. — An 
 
 average day's work for a machine drill in heading or on 
 bench is 50 feet of 2-inch to 2^-inch hole. The great records 
 made on the surface of the ground are not possible in tun- 
 
RAILROAD CONSTRUCTION. OCTo 
 
 nels where the accumulated muck from each preceding blast 
 must be partially removed and the roof trimmed before the 
 columns can be set up. Before firing, drills, tripods, bench 
 hose, and scaffolding must be removed to a safe distance, 
 which requires considerable time. 
 
 1529. Average Progress in Driving. — Eight sec- 
 tions of the New York aqueduct tunnel gave an average 
 monthly progress of 127 feet for full section of about IG X 
 16 feet. The average weekly progress in best ten headings, 
 using IngersoU drills, was 38.73 feet, an average of 6. 45 feet 
 per day. Average monthly progress made by IngersoU 
 drills at Vosburg tunnel on the Lehigh Valley Railroad was 
 202 feet, the tunnel section being about 24 X 26 feet. By 
 hand drills the average monthly progress at the two ends of 
 the same tunnel was 61 and 73 feet, respectively. Material 
 was a hard gray sandstone. A monthly average of 150 feet 
 for a full tunnel section is first-class work. The day is 
 divided into two shifts of ten hours each. There is an hour's 
 interval for changing shifts, and a dinner hour at 12 o'clock 
 noon and 12 o'clock midnight. • 
 
 1530. Lighting. — In modern tunnel work electric 
 lights are almost exclusively used. Oil lamps are to be 
 condemned, as they pollute the air. Tallow candles may be 
 used instead. 
 
 1531. Track work in Tunnels. — In laying the per- 
 manent track, only first-class material is admissible. As the 
 roadbed is free from the action of frost, the track, after two 
 or three thorough surfacings, should require comparatively 
 little attention, except that given by the track walker. Rock 
 ballast is invariably used. Ditches should be large enough 
 to secure complete drainage. Oak ties are to be preferred, 
 of uniform dimensions, and spaced 18 inches center to cen- 
 ter of tie. Tunnel ties should be of the following dimensions : 
 Length, 8 feet; breadth, 8 inches; thickness, 7 inches. 
 There should be at least 8 inches of rock ballast between 
 bottom of tie and tunnel floor, giving a total thickness of 
 
966 
 
 RAILROAD CONSTRUCTION. 
 
 ballast of 15 inches. When the tunnel lining has an invert, 
 i. e., when the section of the floor is concave, the drain is 
 sometimes built under the track, and covered with flags to 
 prevent clogging with ballast. Side ditches are to be 
 preferred, as they are always accessible and easily cleared. 
 
 PROTECTION WORK. 
 
 1532. Classification. — Under this head will be con- 
 sidered surface ditches, changing channels of streams^ crib 
 work, paving, etc. 
 
 1533. Surface Ditches. — Surface ditches are cut at 
 the top of slopes, but at sufficient distance from them to 
 prevent the water from breaking through and washing 
 down the slope. Where the natural slope of the ground is 
 towards the center line and of such a degree that a large 
 proportion of storm water runs off, the surface ditches 
 should be cut before construction commences. When this 
 important precaution is neglected, it often occurs that a 
 great amount of storm water is discharged into open cuts, 
 effectually stopping all work until the water is drained off 
 
 mi^///////////////'/////^^^^^ 
 
 Pig. 455. 
 
 and the ground becomes dry enough to handle. The sight 
 of men and animals floundering in flooded cuttings is too 
 common in railroad work. Many contractors, and especially 
 sub-contractors, are of limited experience, financially irre- 
 sponsible, and generally follow a penny-wise policy. In such 
 cases, the engineer in charge must insist on such precau- 
 
RAILROAD CONSTRUCTION. 
 
 967 
 
 tions being taken as will insure a vigorous prosecution of 
 the work. Ditches are usually paid for at the same price 
 per cubic yard as ordinary excavation. 
 
 Fig. 455 shows a section of a surface ditch which will meet 
 the requirements of most situations. The line A B repre- 
 sents the natural slope of the ground ; C, the surface ditch ; 
 B D, the side slope of the cutting, and D E, the half width 
 of the roadway. The center line of the road is denoted by 
 E F. 
 
 1534. Changing Channels of Streams. — It fre- 
 quently happens when the line of road is parallel to the gen- 
 eral direction of a stream that the windings of the stream 
 repeatedly cross the line of the road. 
 
 By changing the channel of the stream at favorable points, 
 a great saving is made in the cost of construction. A situa- 
 
 FIG. 456. 
 
 tion which warrants the changing of a channel is shown in 
 Fig. 456, in which the located line ABC crosses the stream 
 D G L a.t F and //, requiring an expensive bridge at each 
 point. By cutting a channel across the narrow neck E, both 
 bridges are avoided. Such instances are of frequent 
 occurence. 
 
 1 535. Crib Work. — When the foot of an embankment 
 is subject to the erosion of a current of water, as at L in Fig. 
 456, a crib work of logs and stones is built into the embank- 
 
968 
 
 RAILROAD CONSTRUCTION. 
 
 ment at the exposed point. Protection cribs are ordinarily 
 built of round timber, so combined as to form compartments, 
 which are filled w'th stone to give them stability and with- 
 
 FlG. 457. 
 
 stand the action of the current. A general plan of the crib 
 is given in Fig. 457. 
 
 Cribs serve the purpose both of retaining walls and of re- 
 vetments. Their chief advantage lies in their adaption to 
 situations where the cost of retaining wall foundations 
 would be excessive. They can be readily built on wet, 
 marshy soils or in swift running water. When weighted 
 with stone, the structure sinks, and additional courses are 
 added to the top until the required height is attained. The 
 usual custom is to excavate a pit to a depth of from 12 to 
 18 inches, the bottom course of rangers, i. e., the logs run- 
 ning lengthwise in the crib, being laid close together. Where 
 there is danger of scour from the current, the outside com- 
 partment is sometimes built with an open bottom. As the 
 water works under the crib, the stone drops from the com- 
 partment above, forming a rip rap which prevents further 
 action of the current. The lower courses of the crib, being 
 kept constantly moist, are free from decay. The earth and 
 sand from the sustained embankment are gradually washed 
 into the cavities in the ballast until the whole forms one 
 compact mass of great strength and solidity. In Fig. 457 
 A B is the front elevation, the line A B being parallel to the 
 
RAILROAD CONSTRUCTION. 
 
 969 
 
 direction of the current, C D shows a section of the crib, 
 and E the foot of the embankment which slopes away at the 
 natural slope of earth, viz., 1^ to 1. A plan of the crib 
 is shown at F and the foot of the embankment by the broken 
 line G H. A detail of a joint is shown at K. The log Z, 
 corresponding to r j in the elevation, is called a ranger ; 
 and the log il/, corresponding to C Dm. the section, is called 
 a cross-tie or tie. At each joint a drift bolt, usually a 
 piece of f-inch round iron sharpened at one end, is driven to 
 fasten the logs together. The bolt should be of sufficient 
 length to pass through three logs. A hole of slightly 
 less diameter than the bolt is bored to receive the bolt. A 
 compartment filled with stone is shown at O. 
 
 1536. Paving. — Paving as applied to protection work 
 consists of a stone covering laid on the surface of embank- 
 ments where they are exposed to the action of water. The 
 paving is usually 12 inches in depth and composed of good- 
 
 FiG. 468. 
 
 sized stone of fairly regular shape and even beds, the beds 
 being laid perpendicular to the slope of the embankment, 
 and when finished the whole to present a fairly uniform sur- 
 face. The slope of the embankment should be smoothed and 
 well rammed before the paving is laid. 
 
 A foundation course of heavy stones A, Fig. 458, is laid 
 at the foot of the embankment in a pit from 12 to 18 inches 
 in depth, depending upon the nature of the soil. When the 
 stream has a rocky bed the foundation course is laid 
 
970 RAILROAD CONSTRUCTION. 
 
 upon the surface. The profile of the surface of the 
 ground is shown by the irregular line B C\ the earth 
 embankment by D\ the bed of the stream by E F\ the sur- 
 face of low water by G //, and of high water by L M, 
 The elevation of the protected surface is shown at K, with 
 the joints of the stones well broken. The grade of the 
 roadway is indicated by the line N O. 
 
 ROUTINE WORK. 
 
 1537. Routine Work of the Engineer Corps. — 
 
 The initial work of the construction corps, viz., the checking 
 and betterment of the alinement, the referencing of transit 
 points and cross-sectioning, together with the location and 
 conduct of tunnel work, have already been described. The 
 routine work which occupies the engineers' time from the 
 commencement of the construction to its completion will be 
 considered under one head. 
 
 1538. To Lay Out a Culvert at Right Angles to 
 the Center Line, W^hich is a Tangent: The rule for 
 laying out box culverts was given m Art. 1462. The 
 stakes for pit excavations and for neat lines of masonry are 
 arranged as shown in Fig. 459. 
 
 The broken lines show the outlines of the foundation pit, 
 which extends from six to twelve inches outside the neat 
 lines of the masonry, depending upon the depth of the 
 foundation. Ordinarily six inches is sufficient. The pit 
 should be large enough to permit a thorough inspection of 
 the masonry. The face lines of the masonry are located with 
 the transit. The center line X Fof the culvert being at 
 right angles to the center line P Q oi the road, a plug is set 
 at K, Fig. 459, at the intersection of the center line of the 
 road and the center line of the culvert. The instrument is 
 then set up at K and a right angle turned in the line X V 
 for locating face lines. The height of the embankment at 
 this point is nine feet ; the culvert opening two feet wide and 
 two feet high ; the covering flags are one foot thick, and the 
 parapet one foot high. Then, according to the rule for find- 
 
RAILROAD CONSTRUCTION. 
 
 971 
 
 ing the dimensions of a box culvert, given in Art. 1462, 
 we have 9 feet — 4 feet = 5 feet; 1^ X 5 feet = 7. 5 feet; 7.5 
 feet + 1.5 feet = 9.0 feet ; 9 feet + 8 feet, the half-width of the 
 roadway =17 feet, the distance from center line of road to 
 the end of the culvert. We then measure on the line X V the 
 distance K L = 17 feet, setting a plug at L. On the same 
 line six or eight feet from L set a temporary point M. Then, 
 set large stakes at A and C, twelve inches from M, in lines 
 at right angles to L J/, estimating the angles by the eye. 
 Measure accurately the distances MA and MC, each twelve 
 inches, and drive a lath nail in both stakes, checking the 
 distance ri 6^=24 inches. Then, reverse the instrument, 
 setting a plug at ^V, 17 feet from K, and a point at O for 
 locating the stakes at B and D, checking the measurements 
 
 < ip" 
 
 A 
 
 tI 
 
 rrHl 
 
 -W'i- 
 
 <^K- 
 
 l=U 
 
 *B 
 
 P 
 Fig. 459. 
 
 iLj 
 
 G* 
 
 -Oo-T 
 
 as at A and C. Next, set the instrument at iVand turn the 
 angle A'A^//'= 90°. Applying the rule given in Art. 1462, 
 for finding the length of wing walls, we have 2 feet, the 
 height of abutments + 1 foot, thickness of flags = 3 feet; 
 1| X 3 feet = 4.5 feet; 4.5 feet + 2 feet =0.5 feet, the dis- 
 tance from the face of the opening to the end of wing wall. 
 On the line N //set a stake at H, ten or twelve feet from N, 
 and drive a lath nail in the stake on line. Reverse the 
 instrument, and at the same distance from N set a stake at 
 G, with a tack on line. Next move the instrument to L, and 
 turning a right angle to X V, set stakes at E and F. With 
 these stakes for a guide, the engineer can locate the pit 
 
972 RAILROAD CONSTRUCTION. 
 
 ■rt 
 
 t 
 
 fr- 
 
 \ 
 
 corners with the tape alone. A stake is driven at each 
 corner of the pit, and after the excavation is made and the 
 paving is laid, cord is stretched from 
 the tacks in the stakes from A to B^ C 
 to D, E to F, and G to H , marking the 
 face lines. All other needed lines the 
 mason can lay out for himself. 
 
 1539. When the Center Line 
 of the Road is a Curve. — On 
 
 curves, as on tangents, wherever pos- 
 sible, th« center line of the culvert is 
 placed at right angles to the center 
 line C L on the road, i. e., at right 
 FIG. 460. angles to the tangent D E oi the 
 
 curve at the center D of the culvert (see Fig. 460). The wing 
 walls F and G are parallel to this tangent. The dimensions 
 of a culvert on a curve are the same as those on a straight 
 line, with the same height of embankment. 
 
 1540. When the Center Line of the Culvert 
 Makes an Oblique Angle with the Center Line of 
 the Road, i. e., W^hen the Culvert is Askew. — First 
 find what the length of the culvert would be if it were at 
 right angles to the center line of the road. This will give 
 the base of a right-angled triangle, one of whose angles is the 
 angle of skew. The other is easily found by subtracting 
 the angle of skew from 90°. The hypotenuse will be the 
 required side distance. The wing walls must, in all cases, 
 be parallel to the center line of the road. 
 
 Example. — A railroad embankment is 12 feet in height. A box 
 culvert with opening 3 feet wide and 3 feet high must be built askew 
 at an angle of 70° with the center line. What is the distance from the 
 center line of the road to the center of the opening at the face of the 
 culvert ? 
 
 Solution. — Let A B, Fig. 461, be the center line of the road, and 
 CD the center line of the culvert, .-/ K C = 70^ being the angle of skew. 
 At A' draw E Fat right angles to A B. From the given dimensions of 
 culvert and height of embankment, we have for a right-angled culvert, 
 side distances as follows: 12 — 5 = 7, H X 7 = 10.5, 10.5 -h 1.5 = 12, 
 
RAILROAD CONSTRUCTION. 
 
 973 
 
 12 -h 8 = 20 feet, the side distance. Lay off on K E the distance KG = 
 20 feet. Draw G H perpendicular to KG, forming the right-angled 
 triangle K G H, ot which the angle G K H =W and the side K G = 
 
 Fig. 461. 
 
 20 feet. The side length, which is the hypotenuse K H, is found by 
 
 the formula cos 20° 
 20 
 
 gA'=20feet 
 hypotenuse K H 
 
 , or hypotenuse K H . 
 
 20 
 
 cos 20° 
 
 Tioki;?; - 21.28 feet = the side distance. Ans. 
 .yoyby 
 
 The wing walls for a right-angled culvert of the given 
 dimensions would have a length of 1^x4=6; 6 + 2 = 8 
 feet. Their length L M for the given culvert is found by 
 the following proportion : 
 
 20 ft. : 21.28 ft. ::8 ft. : L M, 
 
 21.28 X 8 
 
 whence the length of skewed wing wall L M =^ 
 
 20 
 
 8.51 feet. 
 
 Side and wing walls are 2^ feet thick and covering stones 
 1 foot thick. The dimensions of the foundation pit are pro- 
 portionately the same as in Fig. 459. The stakes for the 
 neat lines of the masonry are located as in that figure. 
 
 Skewed culverts are of greater length and contain more 
 material than those at right angles to center line of road, 
 and, when arched, they are much more costly to build. 
 Considerable expense may, therefore, be properly incurred 
 in altering a channel so as to obtain a right-angled crossing. 
 
974 RAILROAD CONSTRUCTION. 
 
 1541. Borrow Pits. — Borrow pits are excavations 
 made for the purpose of obtaining additional material for 
 embankments when the regular excavation does not furnish 
 an adequate supply. The simplest form of borrow pit is a 
 trench dug parallel to the center line, a space of suitable 
 width being left between the slope stakes and the edge of 
 the pit. This space, or berme, as it is called, should be 
 six feet in width. Formerly, much of the material taken 
 from such borrow pits was handled with wheelbarrows. In 
 modern practice, where the material admits of it, the 
 wheeled scraper is invariably used. The amount of ma- 
 terial needed for the embankment in excess of that fur- 
 nished by the adjacent cuts is readily calculated. This 
 excess is first excavated from side borrow pits and deposited 
 in place, after which the material from the adjacent cuttings 
 is added. 
 
 Another means of borrowing material, and one which is 
 always adopted where the haul is not too great, is by widen- 
 ing the cuts. In proportion as the cut is widened, the 
 danger of the ditches being filled up by caving embankments 
 or snow is removed. 
 
 Where embankment is made from material cast from the 
 sides of the road, the berme is rarely more than four feet in 
 width. When the building of a road is only possible 
 through the exercise of the greatest economy, a berme of 
 four feet is admissible, even though it may involve increased 
 expense at some future time. Side work of this kind has 
 been let on some of the cheap Dakota lines at a price as low 
 as 12 cents per cubic yard, with an average height of em- 
 bankment of 2 feet. These lines were built through an 
 unsettled country, and carried the settlers who were to fur- 
 nish the future business for the road. As the country set- 
 tled up and traffic increased, these roads were practically 
 rebuilt. The original grade lines, whenever practicable, 
 followed the undulations of the prairie. In rebuilding, 
 these grades were greatly improved by filling up the sags. 
 On many sections the amount of material added was double 
 that put in the original work. 
 
RAILROAD CONSTRUCTION. 
 
 975 
 
 fi^. 
 
 loa 
 
 1542. Calculating the Contents of Borrow 
 Pits. — Where the entire embankment is made from side 
 borrow pits, the contents of the embankment with an allow- 
 ance for shrinkage is taken as the contents of the pits. 
 This process of measurement saves work and is more 
 accurate than measuring the dimensions of the several pits, 
 especially when they are made with wheeled scrapers which 
 leave the pits in irregular shape. 
 
 When the cuts are widened for borrowed material, the 
 surface cross-sections are extended far enough to include the 
 additional excavation. After 
 the work is completed, the 
 cross-sections are again 
 taken. Both cross-sections 
 are platted on the same sheet, 
 which, at once, shows the 
 amount of the excavation. 
 
 Frequently the embank- 
 ment is many times greater 
 in volume than the tributary 
 cuttings, involving an ex- 
 tended borrow pit. In such 
 cases the cross-sections some- 
 times extend several hun- 
 dred feet from the center 
 line. Fig. 462 shows a bor- 
 row pit of this character with 
 the usual form of cross- 
 section. 
 
 In this figure the proposed 
 borrow pit is situated on the 
 left of the center line, and 
 the cross-sections include an 
 area extending in length 
 from station 100 to station 
 105, and in width 250 feet from the center line. A bench 
 mark is established at a convenient distance from the bor- 
 row pit, to be used in taking cross-sections for monthly 
 
 c: S* ® J5 
 »^ e« © *^ 
 
 «♦ ©» *j "^ 
 
 •s *^ •«< 
 Fig. 462. 
 
 104 
 
 109 
 
 102 
 
 101 
 
 lOOtM 
 lOO 
 
976 RAILROAD CONSTRUCTION. 
 
 estimates and final cross-sections. The surface levels are 
 taken as follows: Stakes are driven on the center line 
 25 feet apart, commencing at station 100, and an equal 
 number at corresponding points on a line 350 feet from and 
 parallel to the center line. A rope 250 feet in length, with 
 tags tied at intervals of 25 feet, is stretched from station 
 100 to the stake at A, 250 feet distant. ' A rod reading is 
 then taken at each 25-foot tag and recorded. The line is 
 then moved forward 25 feet, one end being held at station 
 100 -{-25, and the other at B, and the levels on this line 
 taken. In the same way the entire surface is covered. 
 This arrangement divides the surface into squares of 25 feet 
 on a side. For monthly and final estimates the cross- 
 sections are taken at the same points, which insures accuracy 
 and greatly simplifies calculation. 
 
 The surface sections are platted on cross-section paper, 
 and placed far enough apart on the sheet to avoid over- 
 lapping when the monthly and final sections are platted. 
 The cross-sections for each monthly estimate are platted in 
 a different color, excepting the surface and final sections, 
 which are in black. Cross-section books, the leaves of 
 which are ruled like standard cross-section paper, are very 
 convenient for platting sections of borrow pits and special 
 excavations. They may be used in the field, like ordinary 
 note-books, the notes being recorded in pencil, and inked 
 in at the office when leisure time permits. For platting 
 work of this kind, cross-section books are far prefer- 
 able to loose sheets, which are sure to become soiled from 
 repeated use, and, in spite of the greatest care, some are 
 lost. 
 
 1543. Checking the Center Line. — During con- 
 struction, and especially on embankments, the center line 
 should be frequently checked, i. e., run in on the incom- 
 pleted embankment. All materials will not at once take 
 the natural slope of 1^ horizontal to 1 vertical. Frequently 
 the embankment becomes one-sided, and a line of centers 
 reveals at once any irregularity. Contractors of ten sustain 
 
RAILROAD CONSTRUCTION. 977 
 
 a loss on account of material being wasted. It is the duty 
 of the engineer to restore centers whenever they are needed, 
 whether asked for or not. 
 
 1544. Grade Stakes. — When the roadway, either in 
 cutting or on embankment, is brought approximately to 
 grade, a grade stake is set at intervals of 100 feet. On 
 embankments the stake is driven on the center line, with 
 its top at grade. In cuttings the stake is driven at the side 
 of the roadway, and a peg is driven near the foot of the 
 stake. The elevation of the top of the peg is taken, and 
 the amount of cutting which must be made below the top 
 of the peg to reach the grade line is written upon the 
 stake. 
 
 1545. Care of Stakes. — The destruction of stakes 
 by contractors' workmen, and the disregard of them by 
 contractors themselves and their foremen, is about universal. 
 There is no regularly prescribed penalty for such criminal 
 carelessness. The cost of restoring stakes should be charged 
 to the contractor at double price. A literal enforcement of 
 specifications in minor details, where they might be relaxed 
 to the advantage of the contractor and with no detriment 
 to the railroad company, has caused many a contractor to 
 regret his carelessness in this matter. A trick of dishonest 
 contractors is to move slope stakes nearer to the center line, 
 and so reduce the quantity of excavation or of embank- 
 ment. An alert engineer will soon get the true measure 
 of the contractors under him, and detect deceit of this 
 kind. 
 
 1546. Provision for Settling. — Embankments are 
 raised from 5 to 10 per cent, above the established grade to 
 provide for the shrinkage which invariably takes place in all 
 earth embankments. The amount of this percentage is 
 fixed by the engineer in charge, and depends upon the 
 nature of the material composing the embankment. Com- 
 pact clay or gravel will noL settle or shrink more than half 
 as much as soft alluvial soils. 
 
978 RAILROAD CONSTRUCTION. 
 
 1547. Overhaul. — Many contracts for railroad work 
 specify the maximum distance to which material shall be 
 transported at the given price per yard. When the distance 
 exceeds that specified in the contract, the excess is termed 
 overhaul, and a clause in the contract stipulates what addi- 
 tional compensation shall be made for each hundred feet of 
 overhaul. Free haul \s commonly limited to 1,000 feet, and 
 for each hundred feet of overhaul an addition of 1 cent 
 per cubic yard is made to the contract price per yard. In 
 recent years the overhaul clause is omitted from most 
 contracts, as it is almost sure to involve litigation. 
 
 BRIDGE WORK. 
 
 1548. The Location of Bridges. — There are two 
 important factors in the location of a bridge, viz., first, the 
 determination of the angle which the center line of the 
 road shall make with the general direction of the channel, 
 and, second, the measurement of the span. 
 
 In all cases it is desirable that there should be a right- 
 angled crossing, and for bridges of large span the aline- 
 ment is often modified to obtain that result. The amount 
 of such modification, if any, will depend upon the impor- 
 tance and character of the traffic. If the line is for through 
 business where numerous passenger trains are to be run at 
 high speed, the angle of the crossing will be subservient to 
 the alinement; that is, a skewed bridge will be adopted 
 rather than to introduce curvature and mar the directness 
 of the line. 
 
 Skewed bridges are always more expensive and generally 
 less satisfactory than those crossing streams at right angles. 
 
 The character of the crossing being determined upon, 
 the next thing in order is the measurement of the span. 
 This may be effected in two ways, and, when practicable, 
 both methods should be used, the one serving as a check 
 upon the other. The first method is by direct measure- 
 ment; the second by triangulation. Before either method 
 is applied, the center line must be accurately checked and 
 
RAILROAD CONSTRUCTION. 979 
 
 established by fixed monuments set on both sides of the 
 stream. 
 
 1 549. Direct Measurement of Span. — The direct 
 measurement of the span is made as follows: A light strong 
 steel wire is stretched from monument to monument, 
 spanning the stream. One end of the wire is fixed so that 
 the wire is either in actual contact with the point in the 
 monument or directly over it. To the other end a spring 
 balance is attached, which indicates by a dial the amount of 
 tension placed upon the wire. 
 
 The wire is then stretched until the sag is practically 
 removed, and the amount of tension noted. If the wire is 
 not in direct contact with the monument centers, the 
 measurement is found by plumbing from the wire to the 
 monuments. The points of measurement are then marked 
 on the wire and the measurement repeated. The measure- 
 ment should be made at least three times, the wire being 
 subjected to the same tension. As one end of the wire is 
 fixed, any variations in measurement will show at the free 
 end. If the measurements show any considerable variation, 
 the process must be repeated until tJiree measurements 
 practically agree. Two supports are then erected upon a 
 level surface, at a distance from each other equal to the span 
 of the stream, and of such height that the wire w/// clear the 
 groujid when stretched between the supports at the same 
 tension as used in the original measurement. The wire is 
 then stretched with the proper tension, and the points of 
 measurement transferred to the ground by plumbing. The 
 measurement on the ground is made with a standard steel 
 tape, and repeated three times. The average of the three 
 measurements, providing their discrepancy is slight, may be 
 accepted as the correct measurement of the span. 
 
 1550. Measurement of the Span by Triangula- 
 tion. — If practicable, the same monuments used in direct 
 measurement are used in triangulating. The first step is 
 the establishing of a base line, which should be of approxi- 
 mately the sajue length as the span, and laid out on as smooth 
 
980 RAILROAD CONSTRUCTION. 
 
 ground as the situation will permit. The measurement of 
 the base line is made with the greatest care and repeatedly 
 checked. When the ground is practically level the following 
 method is recommended (see Fig. 463): Strong stakes are 
 driven at A, B, C, etc., approximately 100 feet apart, their 
 tops being on the same level and pointed, with a small tack 
 in each stake. The spaces between the stakes are then 
 measured with a steel tape at a tension of about 15 pounds. 
 The measurements are made three times, and the average 
 of them taken as correct. Greater accuracy in measure- 
 ment is secured by having different persons read the tape 
 for each measurement, each recording his own reading, and 
 after the third reading place the three readings in a column 
 
 and take the average for the correct measurement. The 
 sum of the averaged measurements will be the length of the 
 base line A G. Suppose for this case that they are as 
 follows: 
 
 99.892 
 
 99.997 
 
 99.8963 
 
 99.957 
 
 99.9466 
 
 99.880 
 
 699.5689 feet, 
 
 which gives f.or the total length of the ^<2;jf' //«^ 599. 5689 feet. 
 Let Fig. 464 be the plan of the bridge crossing. A and 
 G are monuments in the center line on each side of the 
 river, and B G the base line^ whose length we have deter- 
 termined by direct measurement to be 599.5689 feet. The 
 angles at A, Z>', and G are measured three times, and the 
 average of the readings taken as the correct reading. It is 
 desirable to use a transit which will read to 10 seconds, On 
 
RAILROAD CONSTRUCTION. 981 
 
 bridges of great length the angle readings are taken in three 
 sets of five readings each, and the average of all accepted 
 as the correct reading. This mode of angle measurement 
 was adopted in measuring the span of the Washington 
 bridge over the Harlem river, at New York. Suppose that 
 the average of three readings makes the angle at A^ 
 57° 29' 35"; at B, 59° 01' 03.3" and at G, 63° 39' 20". Their 
 sum is equal to 179° 59' 58.3*, which proves the angle meas- 
 
 FIG. 464. 
 
 urement to be practically correct. The length of the side 
 A G, i. e., the span, is determined by the principles of 
 trigonometry (see Art. 1243), as follows: 
 
 Sin 57° 29' 35' : sin 59° 01' 03.3' :: 599.5G9 : side A G. 
 
 sin 59° 01' 03.3' = .85733 
 599.569 X .85733 = 514.028491 
 
 sin 57° 29' 35' =.84333 
 514.028491 
 
 .84333 
 
 = 609.522 ft. =side^ G. 
 
 If the temperature of the air in this case were 60° Fahren- 
 heit, it may be considered normal, so that there need be no 
 allowance made for the expansion or contraction of the 
 tape. The base line B G'\s practically parallel to the direction 
 
982 RAILROAD CONSTRUCTION. 
 
 of the channel current as indicated by the arrow, and 
 the angle at G of 63° 29' 20' will be the angle of skew to 
 
 which the bridge will be built. 
 
 i 
 
 1551. The Location of Piers and Abutments. — 
 
 The number of piers to be built will depend upon whether 
 the stream is navigable or not, and upon the cost of founda- 
 tions. If the stream is navigable there must be one channel 
 span of such width as the Government authorities shall 
 determine. 
 
 When no provision is required for navigation, the cost of 
 foundations alone will determine the number of piers. In 
 general, the cost of bridges will increase about as the square 
 of the span ; that is, if 07ic bridge is of twice the span of an- 
 other, the first will cost about four times as much as the 
 second. If the stream is shallow and its bed of rock or com- 
 pact gravel or clay, suitable for foundations, it will be 
 cheaper to increase the number of piers, and shorten the 
 spans proportionately. 
 
 1552. Foundations. — This subject is too broad for 
 any but general treatment. A bridge foundation must meet 
 two conditions, viz., stability and security; that is, it must 
 be able to safely support the maximum load imposed upon 
 it, and must be protected against those natural forces which 
 either periodically or continually attack it. The principal 
 enemies of bridge foundations are the erosive action of the 
 current and floating ice, both of which are most active at 
 high stages of water. Bridge piers, with few exceptions, 
 are of stone. Pier foundations may be divided into three 
 classes, viz., rock ox concrete foundations, ///i" foundations, 
 and caisson foundations. 
 
 1553. Rock and Concrete Foundations. — When 
 the bed of the stream is rock or compact gravel, sand, or 
 clay, the pier site is prepared as follows: When of rock, 
 trenches equal in width to the thickness of the outside walls 
 of the pier are excavated to a depth of 12 inches. The 
 bottom of the trench is brought to the same general level, 
 
RAILROAD CONSTRUCTION. 983 
 
 and a layer of concrete added to furnish an even bed for the 
 masonry. As foundations are generally built at low stage 
 of water, the action of the current is but slight. 
 
 When compact sand or hard clay forms the bed of the 
 stream, a dam is built enclosing the foundation site. If the 
 water is stagnant and of a depth not exceeding 4 feet, a 
 trench is dug from 12 to 24 inches in depth, enclosing the 
 foundation, and the trench is then filled with clay and gravel, 
 well mixed and thoroughly rammed, forming a wall which 
 is carried above the surface of the water. The enclosed 
 water is then pumped out and the foundation area excavated 
 to a depth of from 12 to 24 inches, depending upon the 
 erosive force of the current and the weight of the proposed 
 pier. The pit is then filled with well-rammed hydraulic 
 concrete, and the masonry laid precisely as on shore. The 
 two lower courses of masonry are stepped outwards, that is, 
 they project beyond the main body of the pier, increasing 
 the bearing surface of the foundation. These footings or 
 offsets are made from 4 to inches wide. The foundation 
 courses should be of larger stones than those composing 
 the main body of the pier. The faces of the pier are usually 
 battered from |- to 1 inch horizontal to 1 foot vertical. 
 Where the piers must resist heavy masses of floating ice, 
 the up stream ends are brought to an edge, forming ice 
 breakers. 
 
 1554. Cofferdams. — For depths of stagnant water 
 greater than four feet and for less depths having a current, 
 the clay dam is replaced by a cofferdam. This construc- 
 tion consists of two rows of piles which are driven enclosing 
 the foundation site. The distance apart of these rows of 
 piles, as well as the spacing of the piles in the rows, will de- 
 pend upon the depth of the water surrounding the founda- 
 tion site, and the nature of the material into which the piles 
 are to be driven. The piles will also be required to support 
 a platform, upon which are placed the derricks, hoisting 
 machinery, and building material used during construc- 
 tion. 
 
^84 
 
 RAILROAD CONSTRUCTION. 
 
 The usual form of construction of a cofferdam is shown in 
 Fig. 465. Two rows of piles /*, P are firmly driven, enclo- 
 sing the foundation area. 
 Longitudinal pieces of 
 squared timber Wy Uncalled 
 string pieces or wales 
 are bolted to the piles a 
 little above the water level. 
 Directly opposite the string 
 pieces on the inside of the 
 piles, guide pieces g^ g 
 are bolted, the same bolt 
 passing through both string 
 piece and guide. The 
 guide pieces serve to keep 
 the sheet piles 5, 5 in line 
 while being driven. Cross 
 timbers B^ B called bind- 
 ers are notched down on 
 the string pieces to which 
 they are bolted. The de- 
 positing and ramming of 
 the puddle tend to cause 
 the rows of piles to spread. 
 The bindei:s prevent this and give strength and stability to 
 the structure. The plank flooring e supports the derricks, 
 hoisting machinery, building material, etc. The consistency 
 of the cofferdam filling must be such as to exclude the 
 water, and the weight and strength of the entire structure 
 must be sufficient to resist the pressure of the excluded 
 water. Taking the weight of water at G2^ pounds per cubic 
 foot, the external pressure of the water against the sides of 
 a cofferdam is determined by the following rule (see Art. 
 976, Vol. L): 
 
 Rule. — Tlie pressure upon atiy vertical surface due to the 
 •weight of the liquid is equal to the weight of a prism of the 
 liquid whose base has the same area as the vertical surface ^ 
 
 Fig. 465 
 
RAILROAD CONSTRUCTION. 985 
 
 and whose altitude is the depth of the center of gravity of the 
 vertical surface beloiv the level of the liquid. 
 
 Cofferdams are really retaining walls, which were fully 
 described in Arts. 1486 to 1490, inclusive, and the forces 
 acting against them are the same, though somewhat differ- 
 ent in application. In the case of retaining walls, the backing 
 being of earth or broken rock, only that part of the backing 
 included between the back of the wall and the line of natural 
 slope, extending from the inner foot of the wall upward at a 
 slope of 1^ horizontal to 1 vertical, exerts any pressure upon 
 the wall. In the case of water, however, the particles, hav- 
 ing no cohesive force, all exert pressure against the dam. 
 The center of pressure of the water, like the center of pres- 
 sure of the forces acting against a retaining wall with 
 backing level with its top, is taken at one-third of the depth 
 of the water above the bottom. The direction of the water 
 pressure is at right angles to the face of the cofferdam, and 
 the moment of the water pressure is the product of the 
 pressure found by the above rule multiplied by one-third the 
 depth of the water. The moment of the resistance of the 
 cofferdam, that is, its stability^ or resistance to overturiiing, 
 is the product of its weight multiplied by the distance from 
 the inner toe of the cofferdam to the vertical line drawn 
 from the center of gravity of the cofferdam. 
 
 Example. — If, in Fig. 465, the length of a cofferdam is 50 feet, its 
 height 7 feet, its thickness 4 feet, and the 'depth of water 6 feet, {a) 
 what is the pressure of the water against the side of the cofferdam ? 
 (b) What is the overturning moment of the water pressure, and the 
 resisting moment of the dam ? (r) What is the factor of safety of 
 the dam ? 
 
 Solution.— («) 6 x 50 x 3 x 62.5 = 56,250 lb., the pressure against 
 the side of the cofferdam. Ans. 
 
 ib) In determining the moments of the water pressure and of the 
 resistance of the dam, we take a section of the dam 1 foot in length. 
 The pressure of the water against a 1-foot section of the cofferdam is 
 6 X 3 X 62.5 = 1,125 lb. Its center of pressure is at one-third the depth, 
 or 2 feet, above the bottom. The moment of the water pressure is, 
 therefore, 1,125 X 2 = 2,250 lb. Ans. 
 
 Taking the weight of the puddle filling at 130 pounds per cubic foot. 
 
980 RAILROAD CONSTRUCTION. 
 
 we have for the weight of a 1-foot section 7 X 4 X 120 = 3.360 lb. The 
 moment of resistance of the dam is the product of its weight by the 
 perpendicular distance from the inside toe of the dam to the vertical 
 line from the center of gravity of the section. This peVpendicular 
 distance is 2 feet. 3,360 X 2 = 6,720 lb. Ans. 
 
 (c) This moment opposes the moment of the water pressure, which 
 we found to be 2,250 lb. The factor of safety of the dam is, therefore, 
 the quotient of 6,720 h- 2,250 = 2.99, nearly. Ans. 
 
 In this calculation we have ignored the weight of the 
 piles and timber composing the cofferdam, as well as the 
 resisting power of the piles. These would considerably in- 
 crease the factor of safety of the dam. The water pressure 
 per square foot upon the bottom of the enclosed area will be 
 equal to the depth of the water (G feet) multiplied by 02.5, 
 or X 02:5 = 375 pounds. This pressure is resisted by the 
 material composing the bed of the stream and the sheet 
 piling. 
 
 If the bed of the river is composed of compact sand or 
 clay, little trouble need be anticipated. If, however, the 
 bed consists of loose sand and gravel, special provision must 
 be made to exclude the water. 
 
 An effective device used by French engineers is the fol- 
 lowing (see Fig. 400) : Two rows of piles P, P are firmly 
 driven. Wales TF, W and guides G", G are bolted to the 
 piles. A row of close piles C of square timber is driven 
 and bolted or pinned to the outside guide. The foimdation 
 area and the space to be covered^ by the cofferdam filling 
 are dredged to the depth of 3 or 4 feet and the entire pit 
 filled with concrete. Before the concrete has had time to 
 set, the inside row D of close piles is driven, their feet pene- 
 trating 2 feet into the concrete. The clay filling is deposited 
 to the depth of one foot upon the fresh concrete and rammed, 
 so there may be a perfect connection between the puddle 
 and the concrete. This work must be done with dispatch. 
 The remainder may be deposited more gradually. After 
 sufficient time has elapsed to allow the bed of concrete to 
 become thoroughly hardened, the water is pumped out of 
 the enclosure. If the pressure of the water is great enough 
 
RAILROAD CONSTRUCTION. 
 
 987 
 
 to lift the concrete foundation, additional weight must be 
 added to keep it secure until the weight of masonry insures 
 stability. 
 
 P JP 
 
 Fig. 466. 
 
 1555. Pile Foundations. — When the river bed is 
 composed of soft, yielding alluvium extending to a consider- 
 able depth, hut underlaid by a firm soil of ample depth, a 
 pile foundation is commonly adopted. The piles should not 
 exceed in length thirty times their butt diameter, and 
 should be cut from live straight trees. Oak piles are the 
 most durable and strongest; rock elm, spruce, and yellow 
 pine are of about equal strength and durability. The out- 
 line of the proposed pier will to some measure determine the 
 arrangement of the piles, but the general arrangement is 
 always the same, and is as follows: The piles are driven in 
 rows, spaced not less than two and a half feet, center to 
 center, and cover the entire foundation area. 
 
 In some special cases the outside row of piles is made 
 double, the outer piles projecting beyond the outlines of the 
 pier. The calculation of the bearing power of piles and the 
 various methods of driving are fully explained in succeeding 
 pages. The piles, after being thoroughly driven, are sawed 
 
988 RAILROAD CONSTRUCTION. 
 
 off at a uniform level at a suitable depth below low water 
 level. 
 
 A general plan of the pile foundation and the masonry 
 usually adopted for bridge piers is shown in Fig. 407. The 
 dimensions of the foundation from center to center of out- 
 side piles are width 9 feet and length 33 feet, the pier being 
 -*» for a standard double-track roadway. The piles are cut off 
 4 feet below low water. A timber platform, or grillage, 
 of heavy timbers is built upon the piles, to receive the 
 foundation. First, a course of cap timbers is laid crosswise 
 upon the heads of the piles. The caps are commonly 12 by 
 14 inches, and notched down 2 inches upon the pile heads, 
 leaving 12 by 12 inches of solid timber above the piles. 
 The caps extend six inches outside the piles, to which they 
 are fastened with 1 inch square drift bolts. Care must be 
 taken that the tops of the caps are on a uniform level. The 
 second course of timbers is stringers 12 by 14 inches laid 
 lengthwise of the pier, and notched down 2 inches on the 
 caps to which they are drift-bolted at each intersection. 
 They are laid close together, forming a complete flooring. 
 A third course of 12 by 12-inch timbers is laid at right angles 
 to the stringers to which they are securely drift-bolted. The 
 top of the grillage should be at least 1 foot below low water. 
 Upon it the masonry is started. 
 
 In Fig. 467 A shows the side elevation of the foundation 
 and pier; B^ the elevation of the up-stream end of the 
 foundation and pier; C, the arrangement of piles in the 
 foundation, and Z>, the plan of the pier. The courses g and 
 h are the coping courses, the latter forming the seat upon 
 which the bridge rests. The foundation piles are spaced 3 
 feet center to center. The grillage of timber extends on all 
 sides 12 inches from the centers of the outside row of piles. 
 The first course of masonry is laid flush with the outside of 
 the grillage, and extends on all sides 6 inches beyond the 
 second course. The second course projects on all sides 6 
 inches beyond the main body of the pier. 
 
 Beginning with the third course, the north end of the 
 pier gradually develops into a conical-shaped ice breaker, 
 
RAILROAD CONSTRUCTION. 
 
 989 
 
 and in construction consists of the intersection of a cone 
 with a wedge. The curve of intersection is shown in the 
 
 h f—r 
 
 ^ . ■; I 
 
 i' ' \k'^ K.' 
 
 V k ■'." L.l'.TT-T 
 
 na 
 
 iii^:!;:;.k:J''".L,:t-r 
 
 2SzE:~zEE^3: 
 
 £.^ i ,^': :/: te:r - ^. 
 
 ETE 
 
 ^S& 
 
 Ei5 
 
 r d a?;:':^r J"lfc-i^;'— -K^l^ - fc 
 
 
 r.i^p^::''-^^:":. \ ^V'^^: 't''% 
 
 m 
 
 ^;:^x^XM^. :::' - }^ :. ::t 
 
 
 . ,j, ,■.:. Af-.f....liy....tl'i- ..R-r.-.-. . ByvK-.-l'-a.- 
 
 
 
 
 
 
 ,1 '; ' ." pf ; "r ;t^'"g^; '! ^::R '2?i? ;^^ 
 
 
 lEl 
 
 'i^w K;: fe : ii ^ 
 
 'fe, !" ^ ^ 
 
 g^ju-XK.r BJ^Zfey v^^:.k^^E^^ 
 
 s 
 
 feW-.V...^.^; IV>S<r. 
 
 :: r^.:::L ' 
 
 
 Fig. 467. 
 
 elevation by the curve e /, and in the plan by the curve e'f. 
 The arrangement of the stone in each course is shown in the 
 
990 RAILROAD CONSTRUCTION. 
 
 elevation A. It will be observed that in no instance is the 
 bond less than 12 inches, and the proportion of headers 
 (stones showing their short side at the' face of the pier) to 
 stretchers (stones showing their long side at the face of the 
 pier), and their arrangement is such as to form one compact 
 mass of masonry. 
 
 Where there is a rapid current, causing frequent changes 
 of channel, as is the case with many Western and Southern 
 rivers, it may be necessary to rip-rap the foundation. This 
 process consists of depositing stone about the piles to a 
 depth of 4 or 5 feet, the deposit extending several feet be- 
 yond the piles in all directions. Any action of the current 
 tending to undermine the foundation is promptly checked 
 by the rip-rap, which fills any cavity worn out by the 
 current. 
 
 In making working drawings for bridge piers, the arrange- 
 ment of the stones in each course should be carefully planned 
 before the masonry is started. If only two or three courses 
 are planned beforehand, confusion is sure to follow. By 
 furnishing quarrymen with complete plans, they have a 
 wider range of sizes, and will be enabled to take better ad- 
 vantage of the stone as it comes from the quarry. The 
 probable result will be better prices and prompter delivery 
 than when only partial plans are furnished. 
 
 In giving dimensions to quarrymen, no allowance is made 
 for mortar joints, which in bridge masonry are usually one- 
 half inch in thickness. When the given dimension is taken 
 from an angle to the middle of a joint, the stone cutter will 
 deduct one-fourth inch from the dimension for the neat 
 length of the stone. When the dimension is from center of 
 joint to center of joint, the stone cutter deducts one-half 
 inch. Detailed plans are usually sent to the quarry where 
 the stone is cut to dimension, and the several stones for each 
 course numbered, the courses being designated as Course 
 A, Course B, etc., or in some other way. The quarry fore- 
 man lays out the work, deducting the allowance for joints, 
 and the stone is cut, marked, and shipped to the bridge site 
 in shape for laying. Stones of irregular and intricate form 
 
RAILROAD CONSTRUCTION. 991 
 
 are drawn to a large scale of from 1^ to 3 inches to the foot, 
 and often full-sized drawings are made, from which tem- 
 plates of sheet zinc are cut for use in the quarry. 
 
 1556. Stone Suitable for Bridge Masonry. — 
 
 Stone for bridge foundations and piers must be free from 
 seams and defects common to surface stone. Stones con- 
 taining free iron are objectionable, as they are sure to be- 
 come discolored from the action of the elements. Granite 
 is to be preferred, but limestone, hard sandstone, bluestone, 
 and marble are all suitable. In ordinary bridge work, the 
 stone is laid rock face, i. e., with undressed faces, and 
 pitched to line at the joints. By giving the corner stones a 
 draft of two inches, i. e., so. as to show two inches of 
 dressed surface on each side of the angle, an effect of much 
 higher finish is imparted to the entire work at compara- 
 tively small additional cost. 
 
 In cutting the stone, great care should be taken to make 
 the beds even and the stone of uniform thickness through- 
 out, so that when laid the beds will be truly horizontal. In 
 coursed masonry all the stones in each course have the same 
 thickness throughout. A variation of ^ inch in the thick- 
 ness of the stones is readily detected, even by an unpractised 
 eye. All mortar used in bridge building should be prepared 
 under the direction of a competent inspector, and under no 
 circumstances used after setting has commenced. 
 
 1 557. Backing. — The space inclosed by the face stone 
 is usually filled with a less expensive material, called back- 
 ing. In large piers, concrete is much used. It forms a 
 homogeneous mass, and when well rammed, as it always 
 should be, fills all the space between the faces. Rubble 
 masonry is largely used for backing, and in laying, care 
 must be taken to secure proper bond, especially between the 
 backing and the headers which reach from the face into the 
 body of the pier. Piers erected on caisson foundations are, 
 on account of the great cost of sinking, given as small 
 dimensions as are consistent with safety. To give increased 
 weight and strength to the pier, the backing is cut to 
 
992 RAILROAD CONSTRUCTION. 
 
 dimension, so that, when laid, the masonry of each course, 
 with the exception of the joints, forms one solid mass of 
 stone. 
 
 1558. Coping. — The top course of masonry forms the 
 coping and should project 2 or 3 inches over the main body 
 of the pier. When the coping is of two courses, the projec- 
 tion is divided between them, and the outer edge of the top 
 course is beveled to an amount equal to the total projection. 
 The coping courses are usually dressed stone, which adds 
 greatly to the finish of the work. 
 
 1559. Pneumatic Caisson Foundations, — River 
 beds of alluvium extending to great depth, exposed to the 
 scour of a constantly shifting channel, are not suited to pile 
 foundations. The Mississippi and Missouri rivers are stri- 
 king examples of this class. A firm bearing stratum of suf- 
 ficient thickness to support a foundation is often from 80 to 
 100 feet below the bed of the river. To meet these condi- 
 tions, caissons built of heavy timbers are sunk either to bed 
 rock or to a firm stratum of clay or gravel of such depth as 
 to insure permanent safety. 
 
 1560. Test Holes. — After the bridge site has been 
 determined upon and before the bridge plan has been con- 
 sidered in detail, test holes are sunk on the center line at 
 intervals of from 100 to 200 feet, to determine the character 
 of the material forming the river bed. The results of these 
 examinations will largely determine the lengths of the 
 spans. The deeper the foundations the greater will be the 
 spans. Having determined the locations of piers, test holes 
 are sunk at each pier site, in sufficient number to afford 
 ample knowledge of the character of the material to be en- 
 countered in sinking the caisson. A complete record of 
 each test hole is kept, and a sectional profile platted, showing 
 the specification. 
 
 1561. Modes of Sinking Test Holes.— Test holes 
 are sunk either by diamond drills or by driving wrought- 
 iron pipe. Piles are driven to support a platform, upon 
 
RAILROAD CONSTRUCTION. 
 
 993 
 
 which is placed the machinery used in sinking test holes. 
 Wrought-iron pipe is commonly adopted. It is cut in sec- 
 tions of from 6 to 10 feet. The thread on pipe and couplings 
 should be so cut that when coupled the ends of pipe will 
 abut and so prevent the stripping of thread which is liable 
 to result from the repeated blows of the driver. A steel 
 cap, shown in Fig. 468, is screwed to the top of the pipe to 
 receive the blows of the hammer. 
 
 B 
 
 JELO 
 
 n 
 
 C0 
 
 Ei 
 
 Fig. 469. 
 
 Jk^. 
 
 i»-A 
 
 M Water. 
 
 1562. The Driver. — The driver is constructed on 
 the principle of the pile driver. The hammer consists of a 
 section of an oak or other hard wood tree, from 9 to 
 12 inches in diameter, turned to a uniform size and fitted 
 at the sides with steel grooves, through which pass the 
 guides extending the full length of the leaders. An iron 
 ring is fastened in the top of the hammer to which is at- 
 tached the rope used in raising the hammer. This rope 
 passes through a common pulley with wooden sheave, 
 which is fastened with fig. 468. 
 
 rope to the head of the 
 leaders. 
 
 The leaders are of 
 sufficient length to 
 allow the hammer a 
 drop of 4 feet after a 
 new section has been 
 attached. A force of 
 4 or 5 men is required 
 for the efficient work- 
 ing of the machine. 
 In sinking into the 
 earth, the pipe cuts a 
 section equal to the 
 inside area of the pipe. 
 At intervals of 6 or 8 
 feet in sinking, and 
 before an additional section is attached, the pipe is cleared 
 by a sand pump. 
 
 Silt. 
 
 Sand. 
 
 — *'-M 
 Mil 
 
 Coarse Gravel. 
 
 Fine Gravel. 
 
 41 
 
 1" 
 
 Fig. 471. 
 
 Hard Clay. 
 
994 RAILROAD CONSTRUCTION. 
 
 1563. Tlie Sand Pump. — This pump consists of a 
 section of iron pipe of such size as will work freely inside 
 the pipe being driven. Fig. 4G9 shows longitudinal section 
 and plan of sand pump. The valve A consist^ of a ball of 
 iron which, rests in a hollow seat and acts automatically. 
 The pump is lowered into the pipe by means of a rope 
 attached to the ball B. Water is poured into the pipe so 
 that the contents may be reduced to a fluid state. As the 
 descending pump strikes the surface of the water in the 
 pipe, the valve A is forced upwards and the water and sand 
 pass through the hole C. The upper part of the valve 
 chamber D is ribbed, as shown at E. This arrangement 
 confines the valve and at the same time allows the sand 
 and water to pass into the chamber F. When small stones 
 and pebbles enter the pipe and are too large to pass 
 through the valve opening, they must be broken up by a 
 churn drill. The best form of drill is one with a cutting 
 edge or bit similar to that commonly used in steam drills, 
 shown in Fig. 470. 
 
 The drill A B is about 18 inches in length. The cutting 
 edge or bit A is in the form of a cross with equal arms. To 
 the end B an ordinary pipe coupling is attached. The body 
 of the drill is of gas pipe in sections, which are added as the 
 hole deepens. The bit must be kept sharp and the couplings 
 frequently examined that no stripping of thread occurs, 
 which might easily result in the loss of the drill and prevent 
 further sinking. Any change in the material removed from 
 the pipe is readily detected, and the depth of the stratum is 
 determined by measuring from the top of the pipe. 
 
 1 5<>4. Record of Test Holes. — A good form for 
 keeping a record of test holes is given in Fig. 471, which 
 shows a sectional profile, giving the thickness and character 
 of each stratum passed through. The profile given in Fig. 
 471 is of a test hole driven in the bed of a river. After pass- 
 ing through different strata of sand and gravel, a stratum 
 of hard clay is encountered. After penetrating 9 feet into 
 this clay, any further sinking is unnecessary, since 9 feet of 
 
RAILROAD CONSTRUCTION. 995 
 
 hard clay will afford a foundation amply strong for any 
 ordinary bridge. 
 
 1565. Dimensions of Caisson. — The depth of the 
 foundation stratum will affect the size of the caisson as the 
 faces of the pier are battered, increasing the size of the plan 
 as the depth increases. 
 
 For example, suppose the neat dimensions of a bridge pier 
 at the top are 6 feet by 30 feet, and all the faces batter at 
 -^ inch to the foot. If the stratum upon which the caisson 
 is to rest is 93J feet below the top of the pier, and the height 
 of the caisson from cutting edge to deck is 13 feet 4 inches, 
 and the deck is to extend on all sides 6 inches outside of the 
 base of the pier, what will be the dimension of the caisson 
 floor ? As the pier faces batter at a rate of -^ inch to the 
 foot, the increase in each dimension will be as many inches 
 as the pier is feet in height. The height of the pier is 93 ft. 
 4 in. — 13 ft. 4 in. = 80 feet. We, therefore, add 80 inches, 
 or 6 feet 8 inches, to each dimension and we have for the 
 base of the pier, length 30 feet 8 inches, and width 12 feet 
 8 inches. The caisson deck, which projects 6 inches on all 
 sides beyond the pier base, will have a length of 37 feet 
 8 inches and a width of 13 feet 8 inches. The sides of the 
 caisson are battered on all sides to reduce the friction of the 
 earth against them during the progress of sinking. The 
 total batter on each side is 12 inches. This batter will give 
 to the base of the caisson the following dimensions, viz., 
 length 39 feet 8 inches, and width 15 feet 8 inches. With 
 the general dimensions of the caisson floor as determined 
 above, the details may be modified to suit special conditions. 
 
 All caisson plans must meet certain requirements, viz. : 
 There must be adequate supply shafts for admitting men 
 and materials; air pipes for the compressed air, and a con- 
 crete shaft by means of which the concrete used in sealing 
 and filling the caisson may be conveyed from the top of the 
 masonry, where it is mixed, to the caisson ch-amber. Supply 
 shafts are of boiler iron and from three feet to four feet in 
 diameter, depending upon the size of the caisson. The 
 
996 
 
 RAILROAD CONSTRUCTION. 
 
 shafts are built in sections of from four to eight feet, the 
 connections being made by means of exterior flanges, which 
 are bolted together. 
 
 E %=^^'^ 
 
 c 
 
 o ' ^^jr^ 
 
 Q^ 
 
 
 1 566. Air Locks. — The shafts (usually two in num- 
 ber) are fitted with air locks, by means of which men and 
 materials pass from the outer air to 
 the caisson chamber, and vice versa^ 
 without the escape of the compressed 
 air. The principle upon which the 
 air lock is constructed is explained in 
 Fig. 472. 
 
 A is the air lock leading to the 
 shaft B^ which extends to the caisson 
 chamber. A person entering the cais- 
 son finds the outer door in th« posi- 
 tion C. He first closes the air cock 
 D, and swings the door shut, the door 
 taking the position E. He then opens 
 the air cock F^ and the air in the lock 
 A receives the pressure of the air in 
 the caisson, forcing the door E firmly 
 against the casing, which is usually 
 fitted with a rubber gasket, making 
 an air-tight joint. The pressure 
 against the door G being removed, it 
 opens of itself, taking the position H. The person is then 
 in direct communication with the caisson chamber, descend- 
 ing to it by means of the ladder K. At the bottom of the 
 shaft is another door, which is closed when the air lock at 
 the surface is removed for adding another section to the 
 shaft. One of the shafts is used for admitting men and 
 tools, the other for removing material. The air lock used 
 in removing material is provided with a windlass, the axle 
 of which has air-tight bearings and extends through the 
 sides of the lock, being fitted with two cranks which are 
 operated by laborers. Most caissons are fitted with a sand 
 pipe, by means of which the pressure of the air in the 
 
 Fig. 472. 
 
RAILROAD CONSTRUCTION. 997 
 
 caisson chamber is utilized in blowing out the sand or any 
 fine material excavated in sinking. 
 
 1567. Plan of Caisson. — A general plan of a timber 
 caisson is shown in Fig. 473, in which G represents the 
 plan ; H the longitudinal section, and K the cross-section. 
 The walls 6^ and F, enclosing the caisson chamber, are 
 built of three courses of timber 12' X Vl' square. The 
 outer and inner courses consist of superimposed horizontal 
 timbers extending the full length and width of the caisson. 
 The inner course of timbers is laid in an upright position, 
 and extends to within 1 foot of the top of the caisson deck. 
 The timbers in the walls are securely bolted together with 
 drift bolts, each bolt passing entirely through two timbers 
 and penetrating fully 6 inches into the third. As the tim- 
 bers are laid, they are poured with hot coal tar or pitch. 
 At frequent intervals, the horizontal layers of timber are 
 bolted to the upright timbers with screw bolts. The bolt 
 heads must be countersunk and the sockets filled with pitch. 
 Rubber washers are used to insure tight joints. 
 
 The cutting edge a \s oi \ inch boiler plate, 8 inches in 
 width, and backed by 4-inch oak plank. The walls above 
 the cutting edge increase in thickness with each course of 
 timber, attaining their full thickness of 3 feet in the third 
 course. When the caisson is of great size, longitudinal 
 division walls are built dividing the caisson chamber into 
 compartments. Openings are made in these walls to admit 
 of free communication between the various compartments. 
 The caisson shown in Fig. 473 has not sufficient breadth to 
 require any interior division walls. Struts V of 12' X 12' 
 timber placed at intervals of about 8 feet insure lateral 
 stiffness, and 2-inch iron tie-rods Z fitted with turnbuckles 
 prevent the walls from spreading. 
 
 The deck consists of six courses of 12' X 12' timbers so 
 laid as to render the chamber as nearly air-tight as possi- 
 ble, and give the greatest possible stiffness and strength to 
 the structure. The first course A forms the ceiling of the 
 chamber, the timbers extending the entire width of the 
 
998 
 
 RAILROAD CONSTRUCTION. 
 
RAILROAD CONSTRUCTION. 999 
 
 caisson. A layer of zinc enclosed between two layers of 
 felt is laid over the entire ceiling course and ceiling, and 
 floated with pitch. The timbers are laid close, with joints 
 filled with pitch and fastened to the walls with heavy anchor 
 bolts. Course B is laid diagonally to course A and bolted 
 to it, a share of the bolts extending into the side walls. 
 The diagonals stop at 6^ feet from the ends of the caisson. 
 The balance of the course is laid longitudinally, with the 
 alternate timbers passing between the uprights and extend- 
 ing to the outside sheathing of the caisson. Course C is 
 laid transversely ; course D diagonally, the diagonal timbers 
 being at right angles to those in course B^ and stopping at 
 ^\ feet from the ends of the caisson, as in course B, and the 
 balance of the course laid longitudinally, as in that course. 
 Course E is laid transversely. Course /% forming the deck 
 of the caisson, is laid transversely, and the masonry is 
 started upon it. 
 
 An adz is used to give to the outside walls their proper 
 batter. They are sheathed with 4-inch plank, tongued and 
 grooved, the joints of which are filled with either hot coal 
 tar or pitch. The sheathing affords a smooth outside sur- 
 face, which greatly reduces the friction of the earth against 
 the sides of the caisson. The timbers forming the inside 
 walls and ceiling of the caisson chamber are first thoroughly 
 calked and then covered with a layer of 1^-inch hemlock or 
 spruce. This surface is then covered with tarred paper and 
 a second layer of 1^-inch matched spruce boards, with leaded 
 joints. L and M are supply shafts — L for admitting men 
 and tools, and M for removing excavated materials. N is 
 a shaft for admitting concrete for sealing. The small shaft 
 shown between L and N is an air pipe for conveying air 
 from the compressor to the caisson chamber. The pipes /*, 
 Q, and R are sand pipes, by means of which sand and other 
 fine material encountered in sinking may be forced out of 
 the chamber by compressed air. 
 
 The air lock connecting with shaft L is shown in plan at 
 S, and in elevation at T. It is fitted with exterior flanges, 
 which fit the flanges of the sections of the shaft L. 
 
1000 RAILROAD CONSTRUCTION. 
 
 Ordinarily the air lock Tis used. When, however, the masonry 
 has reached the height of the air lock T, the air lock d at 
 the foot of shaft L is closed. The air lock T is then re- 
 moved, another section of shafting added, and the lock again 
 placed in position. The air lock d is then opened and the 
 door fastened to the caisson ceiling. The air lock for shaft 
 Mis placed within the caisson chamber at X. This shaft is 
 used in hoisting excavated material, which is placed in buck- 
 ets and raised by a windlass placed on the top of the masonry. 
 The buckets are filled and placed in the lock. Connection 
 with the caisson chamber is then cut off, and the bucket 
 hoisted to the surface. 
 
 The caisson is usually built near the shore, and when 
 completed it is floated to the pier site, where it is held in 
 position by strong hawsers fastened to cluster piles. The 
 masonry is then started on the caisson deck, and the pres- 
 sure of the air increased as the weight of the masonry causes 
 the caisson to sink. As the caisson approaches the bed of 
 the stream, it must be accurately located, so that when 
 grounded it will take the exact position prescribed for it in 
 the plan. Though of great weight, so long as the caisson 
 floats, its position may be readily changed, but, once 
 grounded, only a slight change of position is possible. 
 
 1568. Sinking tlie Caisson. — Once grounded in the 
 proper position, the sinking of the caisson should be pros- 
 ecuted with vigor. Since all excavated material must pass 
 through an air lock, the process of hoisting it to the surface 
 is necessarily slow. 
 
 After the enclosed area has been excavated to a depth of 
 from 12 to 18 inches, the cutting edge of the caisson is un- 
 dermined to an equal depth. The air pressure is then re- 
 laxed, and the weight of the caisson, together with its load 
 of masonry, causes it to sink until it again rests on a firm 
 footing. When the excavated material is sand, it is usually 
 removed from the chamber by the sand pipe. To effect this 
 a piece of flexible hose is attached at one end to the air pipe 
 near the ceiling. The other end is fitted with a shear valve. 
 
RAILROAD CONSTRUCTION. 1001 
 
 The sand is shoveled into piles, and the hose brought into 
 direct contact with it. The valve is then opened, and the 
 air pressure forces the sand through the hose and air pipe 
 to the surface, where another piece of hose is attached, which 
 carries the sand outside the masonry. When rock is en- 
 countered it is broken by blasting, and removed in buckets 
 through the shaft. The rock encountered in sinking the 
 caisson of the Washington bridge at New York was drilled 
 with an air drill, the compressed air being furnished by the 
 same plant which supplied compressed air to the caisson. 
 Dynamite was used to break the rock. The caisson was 
 lighted by electricity generated by a small dynamo stationed 
 in the compressor house. 
 
 When the caisson is situated at a distance from the shore, 
 the compressor plant is placed on a boat securely anchored 
 at a short distance from the caisson. 
 
 1569. To Determine the Air Pressure in tlie 
 Caisson. — The air pressure in a caisson must be sufficient 
 to resist two external forces — the one due to the atmospheric 
 pressure and the other due to the pressure of the water. 
 The atmospheric pressure is taken at 15 pounds per square 
 inch. The pressure of the water in pounds per square inch 
 is found by multiplying the depth by .434. The sum of the 
 two pressures will be the amount of the air pressure which 
 must be maintained in the caisson in order to exclude the 
 water. 
 
 Example. — At a depth of 50 feet, what will be the working pressure 
 in a caisson ? 
 
 Solution.— .434 x 50 = 21.7; 21.7 + 15 = 36.7 lb. Ans. 
 
 1570. Sealing tlie Caisson. — When the caisson 
 reaches a secure foundation the process of sealing at once 
 follows. This process consists in filling the entire chamber 
 with concrete. The concrete is mixed on top of the pier and 
 conveyed to the caisson chamber through the concrete shaft. 
 This shaft or pipe is from 12 to 18 inches in diameter and 
 fitted at both top and bottom with an air-tight door. While 
 charging the pipe with concrete the bottom door is closed. 
 
1002 RAILROAD CONSTRUCTION. 
 
 When the pipe is full the surface door is shut, the bottom 
 door opened, and the contents of the pipe is discharged with- 
 in the chamber. The concrete is then carried in wheelbar- 
 rows to the extremities of the chamber, which are first filled, 
 the concrete being forced into every cavity. The chamber 
 is completely filled from floor to ceiling, the space about the 
 concrete pipe and shaft being left until the last. When the 
 space has become too small to work in, the workmen leave 
 the chamber, and the remaining space is readily filled with 
 material from the top of the shaft. 
 
 PILE WORK. 
 
 1571. Pile Driving. — There is no subject connected 
 with construction upon which there is so little accurate 
 knowledge. This is partly accounted for by the fact that 
 the material into which piles are driven lies below the sur- 
 face of the ground, and exact knowledge of it is difficult to 
 obtain. 
 
 Nor will a knowledge of the material into which the piles 
 are driven enable the engineer to accurately measure the 
 forces which give to the pile its bearing power. 
 
 The bearing power of a pile depends upon two things, viz. : 
 first, the strength of the pile considered as a column, and, 
 .f^^<7«^, the friction of the ground against the sides of the pile. 
 
 1572. Pile-Driving Formulas. ^A number of for- 
 mulas for guiding engineers in pile work have been prepared 
 by eminent engineers. Most of these formulas are more or 
 less complicated. Some employ values which are difficult to 
 obtain and are not suited to practical constructors. The fol- 
 lowing formula, published by the " Engineering News," and 
 known as the Engineering Nezas' formnla, is very simple, 
 andean be safely followed under all circumstances: 
 
 L = '^ (109.) 
 
 in which L — safe ioadm tons, pounds, or other units; u> = 
 weight of hammer in same unit; /i = fall of hammer in feet; 
 5 = penetration of pile in inches at the last blow, and as- 
 
RAILROAD CONSTRUCTION. 1003 
 
 sumed to be sensible at an approximately uniform rate 
 (and head of pile in good condition, i. e. , not split or broomed). 
 This formula gives a factor of safety of 6, i. e., the actual 
 load which the pile can safely carry is only ^ of its total 
 bearing power, and is applicable to all forms of raflroad con- 
 struction from an ordinary trestle to a drawbridge pier or 
 turntable foundation. 
 
 1573. Methods of Driving. — There are six methods 
 of driving piles. 
 
 First Method. — Ordinary method, in which a hammer 
 weighing from 2,000 to 3,000 pounds or more is dropped 
 from a height of from 20 to 30 feet, falling free upon the 
 head of the pile. Intervals between blows, from 5 to 20 
 seconds. 
 
 Second Method. — The same as first, except that the ham- 
 mer is attached to rope which is slacked on the winding 
 drum, allowing the hammer to fall. This method permits 
 more rapid blows than the first method, but there is a loss of 
 from 20 to 40 per cent, of the force of the blow, caused by 
 the friction of rope on the drum and the hoisting sheave. It 
 also admits of deliberate deception on the part of the con- 
 tractor, who can check the fall of the hammer by the friction 
 brake, delivering blows of not half the force which the 
 amount of fall would indicate. This method is, however, 
 very convenient and fair if properly used. 
 
 Third Method. — By Water Jet. In this a stream of 
 water under pressure is ejected at or near the point of the 
 pile, the water rising along the sides of the pile and remov- 
 ing nearly all the end and side resistance, so that the pile 
 sinks by its own weight, though sometimes extra pressure is 
 added. This method is specially adapted to compact sandy 
 soils, and is often efficacious where all other methods fail. 
 
 Fourth Method. — By Direct Pressure of a Constant 
 Weiglit. This method is applicable to soils of a wet silty 
 nature (practically saturated with water). 
 
 This method is much employed in dock building at and in 
 the neighborhood of New York. The method is sometimes 
 
1004 RAILROAD CONSTRUCTION. 
 
 knovina.s pulling down piles. In the mud of the Hudson 
 river, it is almost impossible to drive a pile by ordinary 
 methods, and the process oi fulling is employed by placing 
 part of the weight of a scow as an insistent weight upon the 
 pile, which sinks it into the mud. 
 
 Fifth Method. — By Nasmyth or Other Steam Pile 
 
 Drivers. In this the hammer weighs from 3,000 to 5,000 
 pounds. The fall is short, usually about 3 feet, but the blows 
 are correspondingly rapid, usually about GO per minute. 
 Otherwise the principle is the same as Method 1. 
 
 Sixth Method. — By Gunpowder Pile Driver. In 
 
 this each blow is a double one, the first caused by the fall of 
 the hammer, and the second by the explosion of the powder 
 on the head of the pile, which in turn throws the hammer 
 upwards. By this method, there is scarcely any intermission 
 in the downward movement of the pile. 
 
 1574. The Striking Force of the Hammer. — In 
 
 calculating the striking force of the hammer, the resistance 
 of the air and friction is not regarded. The leaders, i. e., 
 the upright timbers between which the hammer works, are 
 supposed to be vertical, and the hammer, held in place by 
 well lubricated guides, falls about as freely as though uncon- 
 fined. Thus, a 3,000-pound hammer falling a height of 20 
 feet will strike a blow of 3,000 X 20 = 00,000 ft. -lb. 
 
 1575. Interval of Time Between Blows. — Blows 
 should be delivered at as nearly uniform intervals as possible, 
 and the driving continued until the pile is completely driven. 
 The effect of an interval of rest of even a few minutes is to 
 permit the ground to settle about the pile, thereby greatly 
 increasing its resistance to driving. This effect is most 
 marked in fine, soft, and wet earth, and least in coarse gravel 
 and sand. When driving in soft, wet soils, the penetration 
 from last blow should not be taken for value of S, but after 
 allowing an interval of rest, depending upon the action of 
 the material upon the piles, the mean penetration from 
 several blows should be taken. 
 
RAILROAD CONSTRUCTION. 
 
 1005 
 
 1576. Effects, of Broomed Heads. — According to 
 best authorities, a broomed head will destroy from half to 
 three-quarters of the effect of a blow, even where the broom- 
 ing is not more than half-inch deep. To apply a formula, 
 it will be necessary to adz or saw off the head of the 
 pile so as to secure the full force of the hammer. Apply the 
 formula to several cases, the average result of which may be 
 depended upon. 
 
 1 577. Effect of Driving with Hammer Attached 
 to Rope. — The common practice of driving with hammer 
 attached to rope is to be condemned. The force necessary 
 to uncoil the rope from the drum and the friction of rope on 
 hoisting sheave rob the blow of at least one-fourth of its 
 force. In an actual case in practice, a pile penetrated 0.5 
 foot with a 40-foot fall of a 2,470 pound hammer with line 
 attached to hammer and slacked on drum; it penetrated 
 0.7 foot when hammer was allowed to fall free, the gain in 
 penetration from a free fall of hammer being 40 per cent, 
 greater than when the hammer was attached to a rope. 
 
 1578. Pile Shoes. — In cases where piles are to be 
 driven through a stratum of boulders, old cribwork, or any 
 substance offering great resistance to driving, resort 
 is frequently had to shoeing the piles with either cast or 
 wrought iron. Common forms of shoes are shown in Figs. 474 
 and 475. The shoe in Fig. 474 is of wrought iron, the point 
 
 Fig. 474. Fig. 475. 
 
 Fig. 476. 
 
 Fig. 477. 
 
 being fastened to the pile by spikes through the strap s. The 
 shoe in Fig. 475 is an inverted cone of cast iron. The bolt 
 
1006 RAILROAD CONSTRUCTION. 
 
 «, which fastens the shoe to the pile, is of wrought iron, the 
 cone being cast around it. The fiat base of the cone affords 
 a good bearing for the foot of the pile. The practice of 
 shoeing piles has of late years fallen into disuse. In a great 
 many instances where shoes have failed, piles cut off square 
 have driven fairly well. Shod or pointed piles are liable to 
 cant or drive at an angle. In average ground a pile cut off 
 square at the point will drive better, truer, and almost as 
 rapidly as when pointed. There are, however, situations 
 where either shoeing or pointing is absolutely necessary. 
 
 1 579. Pile Hoops. — To prevent the pile from splitting 
 while driving, the head is surrounded by an iron hoop from 
 one-half to one inch thick and from 1^ to 3 inches wide, 
 as shown in Fig. 47G. They are, however, an uncertain 
 security, especially in hard driving, when often the pile 
 splits below the hoop and bulges to such an extent that it 
 must be cut off before the driving can be continued. 
 
 1580. Slight Penetration Often Indicates Poor 
 Driving. — When the penetration caused by a high fall of 
 a heavy hammer is less than one-fourth inch with oak or 
 one-half inch with soft wood piles, there is danger of over 
 driving. A common mode of failure is shown in Fig. 477. 
 
 1581. Spacing Piles. — Bearing Piles, i. e., those 
 used for foundations, should not be spaced less than three 
 feet center to center; those spaced less than 2^ feet are 
 worse than wasted. Where piles are overcrowded, the soil 
 either becomes churned to a liquid mass or so compressed 
 that those already driven are forced upwards while others 
 are being driven. This effect sometimes occurs where the 
 surface soil is underlaid with quicksand or soil of a buoyant 
 nature, even where there is no overcrowding. A remedy 
 for this trouble is often found in driving piles with the large 
 end or top downwards. Where a considerable area is to be 
 piled, those at the center should be driven first, then 
 working towards the outside of the area. Where the reverse 
 order is used, the soil of the enclosed area often becomes so 
 compressed that piles can not penetrate it. 
 
RAILROAD CONSTRUCTION. 
 
 1007 
 
 1582. Computing Loads. — Calling the average 
 weight of masonry two tons per cubic yard, piles spaced 
 three feet center to center will carry a wall of masonry from 
 50 to 75 feet in height. Piles spaced 24 feet center to 
 center will support a wall of masonry from 75 to 100 feet in 
 height. Greater loads are not warranted by good practice. 
 Where a greater mass of masonry is required, the founda- 
 tions should be stepped out so as to admit another row of 
 piles, thus distributing the pressure over a greater surface. 
 
 Example. — A double row of foundation piles carries an 18-inch 
 masonry wall. The piles are spaced 3 feet center to center, i. e., as 
 shown in Fig. 478, and driven with a 
 1,000-pound hammer, until a fall of 15 
 feet causes a penetration of one-fourth 
 inch. What height of wall can be safely 
 carried by the piles ? 
 
 Solution. — By formula 109, L — 
 
 -^ — -, we have Z, safe load in tons; w, 
 
 weight of hammer = .5 ton; h, height 
 of fall of hammer = 15 feet; 5, last pene- 
 tration = \ inch. Substituting these 
 values in the formula, we have L = fig. 478. 
 
 — ^ — = T^o^^ ^^ tons, i.e., each pile will safely support 13 tons. 
 
 .^5 -f- 1 l./wO 
 
 Each yard in length of the wall is supported by two piles, which 
 
 together can safely carry 24 tons. Taking the average weight of 
 
 masonry at two tons per cubic yard, such a foundation would support 
 
 an 18-inch wall 72 feet in height. Ans. 
 
 Modern depot buildings often carry roof trusses, which 
 tax foundation piles to their safe limit. 
 
 1583. Trestle Loads. — In computing loads for pile 
 trestles it is not too great an allowance to assume that the 
 entire weight of the driving wheel base falls upon each 
 bent, or row of piles, in succession. Suppose, for example, 
 a bent of four piles is driven in building a trestle for heavy 
 railroad traffic. In driving, a hammer weighing 3,000 
 pounds is given a free fall of 30 feet, and suppose the average 
 penetration for the last three blows for the different piles is 
 as follows: 
 
1008 RAILROAD CONSTRUCTION. 
 
 First pile, ^ inch; second pile, | inch; third pile, f inch; 
 fourth pile, f inch. 
 
 Applying formula 109, L = c- i i > ^^ have 
 
 Of 1 A( 1. -1 r 2X1.5X30 90 tons ^^ ^ ^ 
 Safe load for 1 st pile, L = = — — - — = 60. tons. 
 
 . ~|~ X i. 
 
 cf 1 A( ^A -1 r 2X1.5X30 90 tons ^_ ^ 
 Safe load for 2d pile, L = — — = = G5. 5 tons. 
 
 . O i O ~\~ X 1. o / o 
 
 „ - , . , _ , ., J. 2 X 1.5 X 30 90 tons _. . ^ 
 Safe load for 3d pile, L = — ^,^ , ^ — = ^ ^.^^ = 5o. 4 tons. 
 
 .bJio -|- 1 l.u«o 
 
 o i: 1 /If ^^u -1 r 2X1.5X30 90 tons „^ . 
 Safe load for 4th pile, L ■= — = — — — — = 51.4 tons. 
 
 Total safe load for four piles 232.3 tons. 
 
 Taking the weight on wheel base of a consolidation engine 
 at 48 tons, which load each bent must successively carry, and 
 dividing the combined safe load of the four piles, viz., 232.3 
 tons, by 48 tons, the weight on the wheel base, we have a 
 quotient of 4.84, i. e., the bent is able to safely carry 4.84 
 times as great a load as it will ever be required to carry. 
 The above values of JS" are much smaller than can be obtained 
 in many soils. Often the penetration from the last blow is 
 several inches. If, however, the piles are allowed to stand 
 24 hours and the earth to settle firmly about them before 
 being tested with the hammer, it will usually require two or 
 three heavy blows to start them. Supposing the average 
 penetration for the last three blows on the above given 
 piles had been, respectively, 2 in., 3 in., 3^ in., and 2J in., 
 the safe loads would have been the following, viz., 30 tons, 
 22.5 tons, 20 tons, and 24 tons, and the aggregate safe load 
 90.5 tons, which, divided by 48 tons, the weight on wheel 
 base of locomotive, gives a quotient of 2.00 -[- , i- e., the 
 trestle can safely carry twice as great a load as will ever be 
 required of it. 
 
 1584. Piles Acting as Columns. — Piles penetrating 
 through soft, yielding material into a comparatively hard, 
 unyielding material act as columns, and should be given a 
 
RAILROAD CONSTRUCTION. 1009 
 
 factor of safety not less than six. Assuming the weight of 
 hammer at 3,000 pounds and the fall 20 feet, we have a blow 
 of 3,000 X 20 = 00,000 ft. -lb., and for penetration of 1 in., 
 2 in., 3 in., 4 in., 5 in., and 6 in., the safe load in pounds by 
 our formula is 00,000, 40,000, 30,000, 24,000, 20,000, 17,143 
 lb., respectively, which is about ^ of the ultimate breaking 
 load of a 10-inch column of wood of a height of 8 feet, 14 
 feet, 18 feet, 21 feet, 24 feet, and 20 feet, respectively. Where 
 the length of the column without side support is greater 
 than this and the safe load by the formula is less, in the 
 same proportion will the safe load given by the formula ex- 
 ceed the safe load of the column, i. e., the safe load indi- 
 cated by the penetration will be in excess of the load which 
 an unsupported column can carry. 
 
 1585. Pile-Driving Machines. — Pile-driving ma- 
 chines are of two general classes, viz., land machines and 
 floating machines. In both classes the framework of 
 the pile driver is essentially the same. This framework 
 consists of the upright timbers called the guides or leaders 
 which hold the pile in position and between which the ham- 
 mer rises and falls, the wooden bracing of the leaders, and 
 the iron stayrods for the same. 
 
 The machinery for hoisting the hammer may be either a 
 simple crab-winch or a stationary engine, or horse power 
 may be used. For all important modern work a hoisting 
 engine is used. The land machine (see Fig. 479) rests on 
 longitudinal sills A, A, which in turn rest on rollers^. The 
 hoisting machinery, contained in the house C, and the coal 
 and water supply D and £ are well to the rear of the frame- 
 work. When a row of piles is driven, they are cut off at a 
 fixed elevation and capped and temporary or permanent 
 stringers laid. The pile driver is then moved forwards on 
 its rollers, the leaders F projecting far enough beyond the 
 last bent to reach the line of the next row of piles. The 
 engine, boiler, coal and water supply, resting on the rear end 
 of the framework of the machine, serve as a counterweight. 
 The side braces 6", G extend nearly to the heads of the 
 
1010 
 
 RAILROAD CONSTRUCTION. 
 
 leaders, and foot upon the cross timber //, where they are 
 securely braced with timber knees A', K. The back braces 
 Z, J/, and N are bolted at top to the leaders and at bottom 
 to the sills O and /*and to the cross timber Q. The main 
 back braces L are fitted with rounds, forming a ladder, by 
 
 Fig. 479. 
 
 means of which ascent is made to the hammer sheave R. 
 Stayrods 5 and 7", fitted with turnbuckles, extend from 
 the heads of the leaders to anchorages in the sills at the 
 rear end of the framework. The hammer rope ^^ winds on 
 a drum not shown in the drawing. The brackets Fand W 
 
RAILROAD CONSTRUCTION. 1011 
 
 support cross-bars upon which the hammer rests when not 
 working. The sizes of the timbers will depend upon the 
 character of the work to be done and upon the length of the 
 piles to be driven. 
 
 The floating machine (see Fig. 480) is carried on a power- 
 fully built scow A of light draught. The machine shown is 
 of the latest model, and the heaviest in New York harbor. 
 The hull is 56 feet 6 inches long and 23 feet 6 inches wide 
 over all ; each of the sides of the hull is made of four pieces 
 of yellow pine, the two lower 8 X 14 inches, the third 7 X 14 
 inches, the top piece 6 X 14 inches, all securely tied by 
 through bolts. 
 
 The bow planking is oak 5 inches thick ; the bottom and 
 end plank, yellow pine 3 inches thick. The bow is further 
 strengthened by a 16 X 16-inch cross timber at top, and at 
 the stem is an 8 X 12-inch cross timber of yellow pine. Oak 
 is used on the bow as being better adapted to stand the con- 
 stant wear of the piles hauled against it. To prevent knots 
 or inequalities on the piles from interfering with their posi- 
 tion under the hammer, the bow planking overhangs 6 inches 
 in its total height. 
 
 The hull is especially designed to obtain longitudinal stiflf- 
 ness so that the strain between the bow and engine may be 
 properly distributed. To attain this end the hull is strength- 
 ened lengthwise by four longitudinal bulkheads, or keelsons 
 /", each 6 inches thick and braced laterally by four sets of X 
 braces g, made of 6 X 6-inch timber. The hull is further 
 braced in the center by two 3 X 12-inch yellow pine braces 
 //, and tie-rods or " log chains " k of iron If inches in diam- 
 eter. Wale pieces and fender plank / 3 inches thick protect 
 the outside of the hull against chafing; the deck has a crown 
 of about 6 inches in its total width. 
 
 The leaders in, in are made of two pieces of 12' X 12' yel- 
 low pine 67 feet long from out to out, with inside guides ;/ 
 of 4 X 5-inch stuff protected by plate iron one-fourth inch 
 thick; five-eighths inch bolts with countersunk heads fas- 
 ten the inner guides to the main sticks and at the same time 
 secure the iron work to the same. The bottoms of the leaders 
 
1012 
 
 RAILROAD CONSTRUCTION. 
 
 are connected with the 12 X 12-inch bed pieces o by two 
 timber knees not shown, and are tied at the top by the cap/. 
 The arrangement of the back braces q, r, and s is clearly 
 shown in the elevation. Their dimensions are, respectively, 
 6 X 12, 5 X 10, and 5 X 12 inches. They are of yellow pine 
 
 Fig. 480. 
 
 and securely bolted at the top and bottom with seven-eighths 
 inch bolts. 
 
 The side braces « and v are of round timber 16 inches in 
 diameter at butt, and each anchored to the hull by two heavy 
 timber knees. The bed pieces o are fastened down to the 
 hull by four bolts each one inch in diameter, the forward 
 bolt passing through the 16 X 16-inch oak piece w on the 
 
RAILROAD CONSTRUCTION. 
 
 1013 
 
 bow, and the after bolts passing through a cross timber x^ 
 6 X 14 inches. The bottoms of the back braces are secured 
 to the bed timbers by 1-inch strap bolt in each timber, the 
 strap portion of the bolt being 2 inches x i inch in section. 
 A seven-eighths inch through bolt ties the three braces 
 together. The iron stayrods running from heads of lead- 
 ers to the after part of hull are two in number, and each one 
 inch in diameter. 
 
 The hoisting sheaves on top are two in number, placed 
 side by side. They are 12 inches in working diameter, 
 15^ inches from out to out, and 3^ inches wide, and the pin 
 passing through them is 2|- inches in diameter at the sheaves 
 and 2 inches in diameter in the boxes. These dimensions 
 are none too great to stand the severe work frequently put 
 upon the sheaves in hoisting heavy weights and tearing out 
 timber. The fall or hammer rope is 2 inches in diameter, 
 and the "runner " used in hoisting up piles is If inches in 
 diameter. 
 
 The hoisting engine is double-drummed and of nominally 
 25 H. P. The detail of the hammer, shown at E, gives a 
 clear idea of its general design. The weight is 3,300 pounds. 
 
 1586. Sheet Piles. — In building cofferdams for 
 foundations and often in protection work, piles are driven 
 in close contact to prevent leakage. Such piles are called 
 
 LXlXiOj 
 
 I«g^g3 
 
 Fig. 481. 
 
 Fig. 482. 
 
 sheet piles. Sheet piles are always of sawed timber. 
 Where the water is shallow and without a current, 2-in':h 
 planks will be sufficient. As the depth of water and pressure 
 
1014 
 
 RAILROAD CONSTRUCTION. 
 
 increase, the dimensions of sheet piles increase. Usually 
 they are thinner than they are wide, but frequently they 
 are of square timber and as large as bearing piles, and are 
 then called close piles. 
 
 . To make sheet piles drive close together at foot, the points 
 are sharpened as shown at/* in Fig. 481. Any lateral move- 
 ment is prevented by the wales o, o. 
 
 To keep the edges at top close to those already driven, a 
 dog iron, such as shown at a in Fig. 482, is often used. 
 
 A cut of a standard sheet pile driver is given in Fig. 
 483. A general plan of cofferdam illustrating the use of 
 
 Fig. 483. 
 
 sheet piling was given in Fig. 465, Art. 1554. The frame 
 is light, and readily shifted by hand. The hammer A is 
 oak. It is raised by the rope B^ which works in the single 
 pulley C. The hammer is usually worked by hand, three or 
 four laborers generally being sufficient. 
 
 1587. Cost of Pile Driving.— The following figures 
 on the cost of pile driving are taken from reports published 
 in the Engineering Nezvs : 
 
RAILROAD CONSTRUCTION. 
 
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1016 RAILROAD CONSTRUCTION. 
 
 Cost of Piles. — At Chicago, and points on the Mississippi 
 river at and above St. Louis, pine piles cost from 10 to 
 15 cents per lineal foot, according to length and location. 
 Soft wood piles, including cottonwood, rock elm, etc., can 
 be had at any point for from 8 to 10 cents per lineal foot. 
 Oak piles 20 to 30 feet long cost from 10 to 12 cents per foot ; 
 30 to 40 feet long, from 12 to 14 cents; 40 to 60 feet long, 
 from "20 to 30 cents per foot. 
 
 The tables of cost which follow are for various classes of 
 work. 
 
 Railroad Construction. — The accompanying table of cost is 
 exclusive of first cost of piles and of the expense of hauling. 
 Piles used in construction of the Chicago branch of the 
 Atchison, Topeka and Santa Fe Railroad. Piles were 
 driven ahead of the track by a horsepower drop hammer 
 weighing 2,200 pounds. Average depth driven, 13 feet. 
 Table includes cost of driving piles for foundations of Howe 
 truss bridge, and for false work used in the erection of 
 same. The contractor received the same price for all 
 classes of work. . The work was varied, the piles being 
 driven into all kinds of soil. Wages for labor were high, 
 and as follows: Foreman, $4 per day; six laborers, at 12; 
 two teams at $3.50; total cost for labor, 123 per day. Work 
 in progress in the year 1887. 
 
 Number of piles included in report 4,409 
 
 Number of lineal feet included in report. . . .109,578 
 
 Average length of piles in feet 24.8 
 
 Number of days employed in driving 491 
 
 Number of lineal feet driven per day 223.2 
 
 Cost of driving, per pile $2.53 
 
 Cost of driving, per foot 10.2 cents 
 
 Bridge construction, Northern Pacific Railroad bridge 
 over Red River, at Grand Forks, Dakota, constructed in 
 1887. Soil, sand and clay. The penetration under a 2,250 
 pound hammer, falling 30 feet, was 2 to 4 inches. The 
 foreman received $5 per day, stationary engineer $3.50 per 
 day, and laborers $2 per day. 
 
RAILROAD CONSTkT:fCTlON. 
 
 1011 
 
 In the construction of a railroad in Southern Wisconsin 
 during 1885- 87, the contract price — the lowest competitive 
 bid — for piles in place under the piers of several large 
 bridges, averaged as in the following table. The piles were 
 driven in a strong current and sawed off under water; hence, 
 the comparatively great expense : 
 
 CONTRACT PRICE FOR FOUNDATION PILES. 
 
 
 Kind of 
 Driving. 
 
 Contract Price per Lineal Foot. 
 
 Material of Pile. 
 
 For Part 
 
 Remaining in 
 
 Structure. 
 
 For Pile Heads 
 Sawed Off. 
 
 Rock Elm 
 Pine 
 Oak 
 Oak 
 
 Ordinary 
 
 Ordinary 
 
 Ordinary 
 
 Hard 
 
 40 cents. 
 40 cents. 
 48 cents. 
 50 cents. 
 
 15 cents. 
 20 cents. 
 25 cents. 
 30 cents. 
 
 ESTIMATES. 
 
 1588. Calculating Cross-Sections. — Cross-sections 
 are the basis of most calculations employed in determining 
 the amount of material handled in grading the roadway. 
 A full description of the method of taking and recording 
 cross-sections was given in Arts. 1457 and 1458. The 
 cross-section notes are copied into a Qtia^ttity Book, and the 
 total end areas of the cross-sections, together with the 
 partial areas representing the classification of the material 
 as determined by the excavations, are placed in regular 
 order. On the same line, under their proper headings, are 
 placed the quantities of the different materials excavated 
 between .the two points of the line where the cross-sections 
 are taken. 
 
 The common practice in calculating quantities from 
 cross-sections is to multiply the mean or average area in 
 
1018 RAILROAD CONSTRUCTION. 
 
 square feet of two consecutive sections by the distance in 
 feet between them. 
 
 Thus, let A represent the area in square feet of one sec- 
 tion; B, the area in square feet of the next section; C, the 
 number of feet between the sections, and Z>, the total num- 
 ber of cubic feet in the prismoid lying between these sections. 
 Then, by common practice, 
 
 /) = ^±^XC. (IIO.) 
 
 Example. — Two consecutive cross-sections are 50 feet apart. The 
 area of one is 150.4 square feet, and of the other is 191.3 square feet. 
 What is the volume of the included prism ? 
 
 Solution. — Substituting the given quantities in the above formula. 
 
 we have volume = ^^^-^ + ^^^-^ X 50 = 8.542.5 cu. ft. = 316.39 cu. yd. 
 
 Ans. 
 
 1589. The Prismoidal Formula. — A more accurate 
 result is obtained by the use of the prismoidal formula. In 
 applying the prismoidal formula to the calculation of cubic 
 contents, it is requisite to know the middle cross-section 
 between each two that are measured on the ground. The 
 dimensions of this middle section are the mean of the 
 dimensions of the end sections. 
 
 Calling one of the given sections A, the other B, the 
 average or mean section M, the distance between the sec- 
 tions L, and the required contents S, we have, by the 
 prismoidal formula, 
 
 S = ^{A + 4.M+B). (111.) 
 
 In calculating the cubical contents of the prismoid in- 
 cluded between the following sections, both methods of cal- 
 culation will be used and the two results compared. The 
 sections are represented by Figs. 484 and 485, and are 
 denoted by the letters y^i and B. The perpendicular distance 
 between them is 50 feet. The section given in Fig. 484 is 
 composed of the four triangles a, hy f, and d. The triangles 
 
RAILROAD CONSTRUCTION. 
 
 1019 
 
 a and b have equal bases of 9 feet, the half width of the 
 roadway; hence, if we take half the sum of their altitudes 
 and multiply it by the common base we shall have the sum 
 of the areas of the triangles a and b. 
 
 The triangles c and d have a common base "8 feet, the 
 center cut of the section, and if we take the half sum of the 
 side distances and multiply it by 8 feet, we shall obtain 
 
 Fig. 484. 
 
 Fig. 485. 
 
 the areas of the triangles c and d. Taking the dimensions 
 of section A given in Fig. 484, we have 
 
 Area of triangles a -{- b = — '—^ — X 9 = 80. 1 sq. ft. 
 
 21 8 -I- 14 
 Area of triangles c -^ d = — '-^ — X 8 = 143.2 sq. ft. 
 
 Total area of section A — 223.3 sq. ft. 
 
 Taking the dimensions of the section B given in Fig. 485, 
 we have 
 
1020 
 
 RAILROAD CONSTRUCTION. 
 
 9 7 -j_ 2 2 
 Area of triangles a'-^ d'= —- — f- ^ — X 9 = 53.55 sq. ft. 
 
 Area of triangles c'-\- d' — — '■ — ^ — — X 5 = 74.75 sq. ft. 
 
 Total area of section B = 128.3 sq. ft. 
 
 AT f ^- ^ A n 223.3 + 128.3 _^ ^ 
 Mean area or sections A and z> = ir = 175.8 
 
 ^^ sq. ft. 
 
 Contents of the included prismoid = 175.8 x 50 = 8,790 
 cu. ft. =325.6 cu. yd. 
 
 In applying the prismoidal formula we calculate the area 
 of a section midway between the given sections, and for its 
 dimensions we take the mean of the dimensions of the given 
 sections. These dimensions will be as follows: 
 
 Center cut, 
 
 8 + 5 
 
 = 6.5 ft. 
 
 R.ight side distance, — ^^^^r — — = 12.6 ft. 
 
 Left side distance, — '- — ^ — '— = 20.25 ft. 
 
 With these dimensions, construct the section M shown in 
 Fig. 486. 
 
 Fig. 486. 
 
 The area of section M is computed by the same method 
 as that used with sections A and B in Figs. 484 and 485, 
 and is as follows: 
 
RAILROAD CONSTRUCTION.* 1021 
 
 Area of triangles a' + b" = "*"' — -X 9 =66.6 sq. ft. 
 
 on 9_1_ 19 R 
 
 Area of triangles c' -^d" = I^ x 6.5 = 106.6 sq. ft. 
 
 Total area of section M= 173. 2 sq. ft. 
 
 Denoting the distance between the sections by Z, and the 
 cubical contents of the prismoid by S, we have, by applying 
 the prismoidal formula 111, 
 
 S=^{A+4.M+B). 
 
 Substituting known values in the formula, we have S = 
 y (223.3 + 4 X 173.2 + 128.3) = 8,703 cu. ft. = 322.3 cu. yd. 
 Ans. 
 
 Comparing the results, we have 
 
 By averaging end areas, contents = 325.6 cu. yd. 
 By prismoidal formula, contents = 322.3 cu. yd. 
 A difference of about 1 per cent. 
 
 Fig. 487 represents a mixed section of which the part 
 a b c \^ solid rock, the partcde/is loose rock and the 
 part d e g h is earth. The slope a c in solid rock is ^ hori- 
 zontal to 1 vertical. In a section where the excavated 
 material is classified, the foregoing methods of computing 
 areas can not be employed except to check the aggregate 
 area, and when the slopes vary with the different materials 
 other methods must be entirely used. 
 
 Where there is no indication of rock, the slope stakes are 
 set to the usual slope of 1 horizontal to 1 vertical. If rock 
 is encountered before the rock excavation is commenced, 
 the slope is contracted to ^ horizontal to 1 vertical. 
 
 It has been customary to plat irregular sections on cross 
 section paper. The original or surface cross-sections are 
 first platted, and when the top material (usually earth) has 
 been removed, a cross-section of the remaining material is 
 taken and platted on the original sheet, the lines being 
 
1022 
 
 RAILROAD CONSTRUCTION. 
 
 drawn in colored ink. If there is still another classification 
 of material, as shown in Fig. 487, a final cross-section is 
 taken and platted in lines of a separate color. 
 
 The different colored lines at once indicate the outlines of 
 the various materials and assist in checking the calculations 
 of the partial areas. The original cross-sections and the fin- 
 ished section should be in black, the others in distinct, sep- 
 arate colors. 
 
 The partial areas are easiest calculated by dividing them 
 into triangles and carefully scaling all dimensions not 
 given. 
 
 hyCut 13' 
 
 Fig. 487. 
 
 In Fig. 487 we have, remembering that the slopes of /^ 
 and c Ji are 1 to 1 : 
 
 
 
 Total. 
 
 9x3 
 
 = 18.0 sq.ft. 
 
 18.0 sq.ft. 
 
 9X1 
 
 = 9.0 sq.ft. 
 
 
 11X2.1 
 
 = C3.1 sq.ft. 
 
 
 10x2.1 
 
 = 21.0 sq.ft. 
 
 
 Area of triangle a b c oi solid rock = 
 Area of triangle b e /oi loose rock = 
 Area of triangle b e k oi loose rock = 
 Area of triangle c b koi loose rock = 
 Area of triangle c d /& of loose rock =13.2x1. lo= 15.2 sq. ft. 68.3sq. ft. 
 Area of triangle rt'*? ^'- of earth =27.2x1.65= 44.88 sq. ft. 
 Area of triangle ^/^^ // of earth =34. x2.2=74.8 sq. ft. 119.7sq. ft. 
 Total area of section 206.0sq. ft. 
 
 1590. Quantity Books. — Quantity books spoken of 
 in Art. 1588 are of various forms. The following is rec- 
 ommended. It contains station and cross-section notes of 
 Fig. 487, together with the end areas: 
 
RAILROAD CONSTRUCTION. 
 
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1024 RAILROAD CONSTRUCTION. 
 
 This form of notes includes both left and right-hand pages 
 of the book, and the classification of material meets the re- 
 quirements of most railroad work. When the material in- 
 cluded between two consecutive cross-sections is of the same 
 character, the prismoidal formula should be used in calcu- 
 lating the cubical contents of the. included prismoid, but 
 when the sections are classified, as in Fig. 487, the mean 
 area of each material shown in both sections should be taken 
 and multiplied by the distance between the sections. When 
 one kind of material, such as rock, shows in one section and 
 not in the next following, the point where that particular 
 material ends should be determined and the distance from it 
 to the section containing rock should be measured. This 
 mass of rock will be considered either as a pyramid or a 
 wedge, according to its form. When of wedge form, its vol- 
 ume is the product of its base by one-half its altitude or 
 length, and when of pyramid form its volume is the product 
 of its base by one-third its altitude or length. 
 
 The partial and total areas of each section are placed on 
 the same line under their proper headings. As the number 
 of the station at which each cross-section is taken is given 
 in the station column, the distance between any two sec- 
 tions is readily found by subtraction. The quantities are 
 carried out on the same line as the end areas and placed 
 under their proper headings. Thus, in calculating the ma- 
 terial between Sta. 50 and Sta. 50 -f- 50, place the quanti- 
 ties on the Sta. 50 + 50 line, which is next below Station 50. 
 When a page of the quantity book is filled, add the several 
 columns of quantities which are given in cubic feet, and re- 
 duce them to cubic yards by dividing by 27. At the end of 
 each mile section a blank page should be left in the quantity 
 book. A summary of the total yardage of each kind of ma- 
 terial handled in the grading of the section is then made out 
 and placed on this blank page, together with the contract 
 price and value of the work. Wherever a trestle or cul- 
 vert occurs, a space should be left in the quantity book at 
 the proper station, large enough to contain a sketch and 
 estimate of the materials for the same. Spaces should alsq 
 
RAILROAD CONSTRUCTION. 1025 
 
 be left for borrow pits and any special excavation. All 
 these partial estimates will appear in the summary in proper 
 order. The following will serve for a guide: 
 
 SUMMARY OF QUANTITIES. 
 
 SECTION lO. 
 
 Excavation. 
 
 Earth 10,000 cubic yards @ 20c $2,000.00 
 
 Loose rock 1,500 cubic yards® 40c 600.00 
 
 Solid rock 850 cubic yards @ 80c 680.00 
 
 Borrow 2,000 cubic yards @ 20c 400.00 
 
 Masonry. 
 
 First-class .... 190 cubic yards @ 110.00 $1,900.00 
 
 Second-class ... 220 cubic yards @ 6.00 1,320.00 
 
 Rubble 270 cubic yards® 4.00 1,080.00 
 
 Rip-rap 300 cubic yards ® 60c 180.00 
 
 Paving 120 sq. yd. @ 90c 108.00 
 
 Piling. 
 
 4,000 lineal feet @ 30c .^ $1,200.00 
 
 Trestle Timber. 
 
 100,000 feet board measure, in work @$30 $3,000.00 
 
 Iron. 
 
 3,000 pounds @ 4c $120.00 
 
 Total cost of grading, masonry, and trestling on 
 
 Section 10 $12,588.00 
 
 1591. Monttily Estimates. — On or about the last 
 day of every month during the progress of construction, 
 measurements are taken to determine the total amount of 
 work done and materials furnished up to that date. It is 
 frequently necessary to take measurements for both monthly 
 and final estimates at other times than the closing days of 
 the month. This is especially the case in foundation work 
 where the masonry is started as soon as the excavations are 
 completed. When the roadway has been completed, the 
 
1026 RAILROAD CONSTRUCTION. 
 
 monthly and final estimate will be the same. The quanti- 
 ties are taken directly from the quantity book, where end 
 areas of sections and volumes are carefully calculated and 
 carried out in regular columns. 
 
 An approximate estimate is made of all work in progress, 
 care being taken to make it as exact as the nature of the 
 work will allow. 
 
 A special field book is used for monthly estimates, in 
 which a description is given of the particular work or struc- 
 ture measured, together with the date of measurement. The 
 notes consist principally of the cross-sections of incompleted 
 roadway. Wherever the roadway is completed to grade, 
 the word " completed " is commonly written opposite the 
 station and the quantities computed from the original cross- 
 sections. Notes of foundation pits are made doubly clear 
 by a sketch of the excavation with dimensions marked on 
 the outlines. All special work, concerning which a misun- 
 derstanding may possibly arise, must be particularly 
 described. 
 
 Materials, such as lumber, stone, etc., furnished by the 
 contractor and not put into any structure at the time the 
 estimate is taken, should be measured and the amounts 
 placed under the head of temporary allowances^ the price 
 allowed being somewhat less than the actual value of the 
 material as delivered. 
 
 Blank forms are used by the resident engineer in reporting 
 monthly estimates. In these forms a column is provided for 
 each of the different classes of material and work contained 
 in the contract. The stations are numbered in the first col- 
 umn in regular order, and opposite each station in the 
 proper column the amount of excavation, masonry etc., is 
 written. 
 
 An estimate is made for each particular mile section into 
 which the line of railroad is divided for letting. 
 
 The resident engineer should keep, in a separate book, a 
 record of each monthly estimate. 
 
 The monthly estimates are forwarded to the division en- 
 gineer, who reviews them, copying the footings of the several 
 
RAILROAD CONSTRUCTION. 1027 
 
 columns into a separate book in which the sections of his di- 
 vision are placed in regular order. The prices are affixed to 
 the quantities and the total amounts carried out. From the 
 totals, the amounts of previous estimates are deducted, and 
 the remainder is the amount due the contractor for the 
 month. From this amount a certain percentage (usually 15 
 per cent.) is deducted to be reserved by the company until 
 the completion of the contract. 
 
 A summary of the monthly estimate is then forwarded by 
 the division engineer to the chief engineer for auditing and 
 approval. 
 
 1592. The Final Estimate. — The final estimate is 
 a complete statement in detail of the amount of work done 
 and the materials furnished in the construction of the road, 
 and is the basis of final settlement between the company and 
 the contractor. It should be commenced as soon as con- 
 struction is under way and continued as fast as the necessary 
 data may be collected. 
 
 Full notes must be kept of each particular structure and 
 complete measurements taken while the work is under way 
 and the circumstances fresh in mind. This is particularly 
 important in the case of bridge and culvert foundations and 
 other structures, either under water or covered with earth at 
 the completion of the work. These sketches and notes will 
 be recorded at their proper station in the quantity book 
 described in Art. 1590. When the work is completed, a 
 final summary is made containing the aggregate quantities 
 of the entire line. 
 
 Full notes are kept of all classified materials and of all 
 material affected by length of haul (providing a haul clause 
 occurs in the contract) and arranged in the order in which 
 the work occurs on the line. 
 
 The calculations for final estimate limit the monthly 
 estimates and guide the engineer in making approximate 
 estimates of either work or material. 
 
TRACK WORK. 
 
 TRACK LAYING. 
 
 1593. There is no department of modern railroad 
 engineering which is receiving so much attention as the 
 care and maintenance of the track. In the great strife for 
 business, freight and passenger rates have been reduced to 
 a minimum, and to meet these conditions speed and train 
 loads have been nearly doubled. These conditions demand 
 a good track. 
 
 A track to be good must be laid on sound ties, well 
 ballasted and surfaced, full spiked and bolted, and in perfect 
 line and surface. 
 
 1594. New Road. — In America practically all newly 
 constructed railroad is built of new material throughout, 
 though the cross-ties are often cheap and the rails light. 
 
 CROSS-TIES. 
 1595. Cross-ties are of wood. Their size and variety 
 of timber will depend upon the locality and financial ability 
 of the railroad company. The best ties are of white oak. 
 
 The following list gives in a descending scale the com- 
 parative values of woods for cross-ties : 
 
 Hard Wood. Soft Wood. 
 
 White Oak. Red Cedar. 
 
 Rock Oak. Black Cypress. 
 
 Burr Oak. White Cedar. 
 
 Chestnut. White Cypress. 
 
 Southern Pine. Tamarack. 
 
 Walnut. Butternut. 
 
 Cherry. White Pine. 
 
 Red Beech. Hemlock. 
 
 Red Oak. Spruce. 
 
1030 
 
 TRACK WORK. 
 
 It is generally accepted that hewn ties are superior to 
 sawed ties. The surface of a well-hewn tie is a series of 
 comparatively smooth surfaces. The effect of the ax is to 
 close the pores as the chip is removed, which tends to exclude 
 the moisture. The effect of the saw is exactly the reverse 
 of the ax. While given, an average smoother surface, it 
 tears the fiber of the wood, leaving the pores open. These 
 minute broken fibers which cover the entire surface of the 
 tie act like sponges in attracting and retaining moisture, 
 and eventually hasten decay. 
 
 1 596. Importance of Seasoning. — Too little atten- 
 tion is paid to the seasoning of cross-ties before they are 
 laid in the track. This is especially true on newly con- 
 structed lines where scarcity of capital and the necessity for 
 keeping down expenses compel the use of the cheapest 
 material and methods. Cross-ties thoroughly seasoned will 
 last fully one-quarter longer than those used while green, 
 and they are better in every way. Well-seasoned wood will 
 hold the spikes better and resist the shearing tendency of 
 
 the rails due to passing 
 loads better than green 
 ties. The most favorable 
 months in Northern lati- 
 tudes for cutting ties are 
 August, December, Janu- 
 ary, and February. Dur- 
 FiG. 488. ing these months there is 
 
 comparatively no movement in the sap of the trees. The 
 ties should be hewn to uniform thickness and piled in square* 
 piles about 4^ feet in height, as shown in Fig. 488, so as to 
 admit of the free circulation of the air and to hasten the 
 seasoning process. 
 
 1597. Specifications for and Inspection of 
 Cross-Ties. — Specifications should include dimensions, and 
 kind and quality of timber. Ties for standard gauge tracks 
 should be from 8 to 9 feet in length, from 6 to 8 inches in 
 thickness, and show not less than 6 inches of face. The 
 
TRACK WORK. 1031 
 
 standard tie is 8 feet 6 inches in length, 7 inches in thick- 
 ness, and shows at least 7 inches of face. In the Northern, 
 Middle, and Western States, log ties, i. e., ties cut from 
 entire trees and showing two rounded sides, are principally 
 used. In the Southern, Atlantic, and Gulf States, yellow 
 pine ties are in almost universal use. They are square hewn 
 and made of heart timber, not more than 1 inch of sap being 
 allowed on the corners. In Southern latitudes, where the 
 process of decay goes on throughout the year, sap timber is 
 almost worthless. The sap timber soon softens, the spikes 
 loosen and the rails cut into the wood, leaving the track in 
 a dangerous state. In those portions of the South where 
 oak is abundant, oak ties are much used. They are generally 
 square hewn. This is a mistake, especially if the ties are 
 cut from young thrifty trees (and no other timber should be 
 used), since a considerable portion of the weight of the tie 
 is sacrificed in squaring. This lost weight is all needed to 
 give stability to the track. The ties should be cut off square 
 and to uniform lengths, and be of a uniform thickness 
 throughout their entire lengths. Before being inspected, 
 they should be delivered along the right-of-way of the rail- 
 road and piled in regular piles, each tie showing both ends. 
 Ties are commonly graded as firsts and seconds. The in- 
 spector carries a brush and pot of paint, marking each class 
 of ties with a distinctive mark. Firsts are usually marked 
 by a full circle, and seconds by a cross. 
 
 PREPARATION OF A ROADBED. 
 1598. It is a rare thing to find a new roadbed in proper 
 condition for track laying. Often it is in poor surface, being 
 left by the contractors in a rough, uneven state. If the track 
 is being laid in heavy, wet weather and .the ties are being 
 distributed by teams, the wheels are sure to cut deeply into 
 the roadbed, and unless some precaution is taken to bring 
 the tops of the ties to a uniform surface, there is great 
 danger of the rails being bent by the passage of the 
 construction train. 
 
1033 TRACK WORK. 
 
 1599. Track Centers. — Center stakes marking the 
 alinement are driven at intervals of 100 ft. on tangents and 
 50 ft. on curves, where the degree of curve does not exceed 
 12°. On curves exceeding 12°, stakes should be driven at 
 intervals of 25 ft. A tack is driven in each stake, marking 
 the center of the track. Grade stakes for surfacing ties 
 should be placed at intervals of 10 ft. A straight edge 
 placed upon these stakes marks the grade for the inter- 
 vening ties. The ties are bedded with earth taken from 
 the roadbed and tamped with the shovel. 
 
 The placing of grade stakes so close together is contrary 
 to common practice, but the increased labor for the engineer 
 is more than compensated for by the saving of the time or- 
 dinarily consumed in sighting in ties where grade stakes are 
 set at intervals of 50 or 100 ft. The surface is sure to be 
 better where the straight edge is brought into use, and the 
 danger of kinking rails or bending them out of surface is 
 obviated. 
 
 1600. Track - Laying Machines. — Track - laying 
 machines have been used to some extent. The ties, as well 
 as rails and fastenings, are carried on cars. With some 
 machines they are conveyed to the front on rollers; in 
 others, on an endless belt which runs along the sides of the 
 cars. The process of track laying is as follows: Two rail 
 lengths are laid, bolted, and partially spiked, and the ties 
 partially bedded. The cars are then run forwards and the 
 process repeated. The progress of track laying with a ma- 
 chine is limited by the amount of track which can be full 
 bolted, spiked, and made fit for the running of trains, and 
 ranges from 1 to 1^ miles per day, 1 mile being a common 
 average. Economy in the force of track layers and the 
 saving of team work are the principal advantages claimed 
 for track-laying machines. In mountainous country, where 
 the roadbed is difficult of access to teams, the track-laying 
 machine has decided advantages over ordinary methods, but 
 in open country where the roadbed is readily accessible, 
 both ties and rails should be hauled by teams. With 
 
TRACK WORK. 
 
 1033 
 
 material distributed a considerable distance in advance of 
 the construction train, a much larger force of men may be 
 economically employed. If the track laying is to be rushed, 
 the track-laying machine must take second place. 
 
 1 60 1 . Track-Laying Outfit. — Before starting out to 
 lay new track on a new road, the boss track layer should 
 make requisition for all the tools necessary for expeditious 
 work. These tools are loaded on a car and shipped to the 
 point where work is to be commenced. Everything should 
 be in readiness for making a good beginning before the men 
 are brought on the ground. Any lack of proper tools is cer- 
 tain to cause awkward and often serious delay, and opera- 
 tions must often be suspended until the lack can be supplied 
 from headquarters. The following list of tools will amply 
 supply a force of 100 track layers, with a reserve for extra 
 men in case they should be needed, and will be sufficient to 
 take the places of tools worn out or broken until a supply 
 can be brought to the front : 
 
 Hand cars 1 
 
 Steel cars 3 
 
 Push cars 2 
 
 Shovels 150 
 
 Picks 50 
 
 Lining bars 12 
 
 Claw bars 12 
 
 Tamping bars 12 
 
 Nipping bars 24 
 
 Cold chisels 24 
 
 Rail punches 6 
 
 Chopping axes 6 
 
 Hand axes 6 
 
 Striking hammers 42 
 
 Bush scythes and snaths, 
 
 . each 3 
 
 Hand saws 6 
 
 Adzes 6 
 
 Track gauges 12 
 
 Covered water barrels. . . 2 
 
 Track levers 2 
 
 Chalk lines 2 
 
 Spirit levels 6 
 
 Tape lines. 6 
 
 Nail hammers 3 
 
 Monkeywrenches 3 
 
 Lanterns, red 3 
 
 Lanterns, white 3 
 
 Water pails 6 
 
 Tin dippers 6 
 
 Oil cans 2 
 
 Oilers 3 
 
 Gallons of oil 2 
 
 Pick handles 24 
 
 Nails, 10 penny, kegs ... 1 
 Nails, 20, 40, GO penny, 
 
 kegs, of each 1 
 
 Cross-cut saws 3 
 
1034 
 
 TRACK WORK. 
 
 Adz handles 6 
 
 Ax handles 6 
 
 Maul handles 30 
 
 Red- flags 12 
 
 Sledges, 16 lb. each 2 
 
 Grindstones 1 
 
 Track wrenches 24 
 
 Iron tongs, pairs 3 
 
 Rail forks 6 
 
 Expansion shims 200 
 
 Switch locks 6 
 
 Rail drills 2 
 
 Torpedoes, dozens 4 
 
 Track jacks 4 
 
 Rail benders 2 
 
 Curving hooks 2 
 
 Post hole diggers 2 
 
 Tie poles, 30 ft. long 2 
 
 Tie lines, 1,000 ft. long. . 1 
 
 Sets double harness 1 
 
 Sets single harness 1 
 
 Sets double and single- 
 trees, each 1 
 
 Wagon 1 
 
 Scraper 1 
 
 Horses or mules 2 
 
 Tool boxes 2 
 
 Files 6 
 
 l:J^-inch rope, feet 300 
 
 Car accommodations for track laying should be the 
 following : 
 
 One supply and office car. 
 One kitchen car. 
 Two dining cars. 
 Three sleeping cars. 
 
 Where track laying is being done a long distance from 
 the base of supplies, a blacksmith with forge and tools 
 should accompany the outfit. 
 
 1 602. Distributing Ties.— When ties are distributed 
 along the foadbed by teams, they are strung out in proper 
 numbers, so that the labor of carrying them to their place in 
 the track may be as light as possible. The largest of them are 
 reserved for joint ties, the joints being located by measuring 
 from the ends of the rails already in place in the track. By 
 measuring with a 30-foot pole, the joints of rails may be 
 accurately located, a small stake driven marking each joint. 
 This practice admits of the placing of ties several rail lengths 
 in advance of the rail, thus affording working room for a 
 much larger force than could otherwise be handled. A tie 
 line for lining the ends of the ties is spaced at the proper 
 
TRACK WORK. 1035 
 
 distance from the center line and stretched taut, being 
 fastened at suitable intervals by well-driven stakes. Joints 
 should not be located at any considerable distance in ad- 
 vance of the rails, as the measurements are likely to vary a 
 little and soon accumulate an error. These inaccuracies 
 are obviated by checking the measurements frequently from 
 the ends of the rails already in place in the track. Care 
 must be taken to place the ties at right angles to the center 
 line. Ties laid askew prevent proper gauging of the track. 
 Ties should be assorted with reference to thickness in order 
 that those of uniform thickness may come together in the 
 track, thus greatly reducing the labor of bedding. 
 
 1603. Bedding Ties. — As soon as the- ties are dis- 
 tributed and lined they are bedded for the rails. The process 
 is as follows : The straight edge is placed on the grade stakes 
 and the faces of the ties brought to a uniform surface by 
 first sinking those which are above grade and then raising 
 those remaining to grade by throwing dirt or ballast under 
 them and settling them to the correct level. It has been a 
 general and most pernicious custom to spike the rails to the 
 ties without bedding. Most rails will be found to carry 
 from one to a half dozen swinging ties, some of which are 
 sure to get skewed before the ballast secures them. The 
 track is full of undulations and as the foundation is rough 
 and uncertain, many of the rails are kinked or surface-bent 
 by the passing construction train. Where ties are bedded, 
 the spiking can be better and more expeditiously done, and 
 the construction train can follow at once with entire safety. 
 
 If the track is to be ballasted with cinders or broken stone, 
 the ties must not be bedded, in order that the ballast may 
 occupy all the vacant space in the roadway. Nevertheless, 
 the dressing down of uneven places in the roadway before 
 distributing the ties is time and money well spent. The 
 ballasting must be kept well up with the track laying if 
 kinking of the rails is to be avoided. 
 
 1604. Organization of Forces. — The foreman in 
 charge of track-layers should thoroughly organize his forces, 
 
1036 
 
 TRACK WORK. 
 
 placing each man where his work will give the best results. 
 Spikers and iron men are first choice. They should be alert, 
 sober men, and should be paid higher wages than the rest, 
 as upon their efficiency depends the excellence and progress 
 of the work. The prospect of promotion which is thereby 
 held out to the others promotes the industry and discipline 
 of the entire force. 
 
 A small surfacing gang immediately follows the track- 
 layers. Any scarcity of men at the front can be supplied 
 from this gang, and any extra men at the front can at any 
 time be profitably added to the surfacing gang. 
 
 1605. Locating Joint Ties. — The foreman should 
 detail two trustworthy men to locate the joint ties. They 
 carry a measuring pole of the standard rail length, usually 
 30 feet, and locate the joints by measuring from the ends of 
 the fixed rails. They also complete the work of spacing the 
 intervening ties, which can not be done until after the joint 
 ties are placed. 
 
 TRACK JOINTS. 
 1606. There are two forms of rail joints in general use, 
 viz., suspended and supported. Both forms have merits 
 peculiar to themselves, but both are rarely found on the 
 
 1^ 
 
 Fig. 489. Pig. 490. 
 
 same road, either one or the other being used exclusively. 
 A cut of a suspended joint is given in Fig. 489, and of a 
 
TRACK WORK. 1037 
 
 supported joint in Fig. 490. In the suspended joint there 
 are two joint ties spaced about 6 inches in the clear. The 
 joint is spaced midway between the ties, which should be 
 carefully selected, have broad faces, and be of uniform thick- 
 ness throughout. In the supported joint the tie is placed 
 directly under the joint. The angle splices A and B, which 
 are shown in section at C, vary in length from 24 to 36 inches. 
 Those 24 inches in length have 4 bolts, and those from 
 30 inches upwards have 6 bolts. A joint to be perfect should 
 have the same strength as the rail itself, but such a joint 
 has not yet been devised. A vast amount of time and 
 money has been expended upon the development of rail 
 fastenings. Iron chairs and fish-plates, once in universal use, 
 have disappeared. The angle splice shown in section at C, 
 Fig. 489, is generally accepted as the best rail fastening yet 
 invented. The prerequisite of a good rail fastening is a 
 strong shoulder which will closely fit under the head of the 
 rail, and a broad base closely fitting the base of the rail and 
 extending its entire width, reaching down so as to bear upon 
 the tie. The plates do not fit closely to the web of the rail, 
 
 H 3^-0- — ->f 
 
 ae 
 
 FIG. 491. 
 
 but are curved as shown in the section C. The holes in the 
 plates as well as those in the rails are oblong so as to admit 
 of the expansion and contraction of the rails due to changes 
 of temperature. 
 
 Bolts should be of a size suited to the weight of the rail, 
 though there is small danger of getting them too heavy. 
 Track bolts are usually fitted with nut-locks of either metal 
 or fiber. Trackmen should avoid straining the bolts when 
 setting up the nuts. A half turn of the wrench after the 
 nut has come to a bearing is sufficient. Though there are 
 still some railroad men who strongly adhere to the supported 
 joint, yet general experience has abundantly proved the 
 
1038 
 
 TRACK WORK. 
 
 superiority of the suspended joint. The angle splice in gen- 
 eral use on trunk lines is 3 feet in length, carries 6 bolts, and 
 complete weighs from 40 to 60 pounds. The joint is sus- 
 pended, and the ends of the splices also come midway 
 between ties, as in Fig. 491. 
 
 The angle splices should be slotted and spikes driven 
 through them into the tie to prevent the creeping of the 
 rails. In the suspended joint there are two slots in each 
 splice, as shown in Fig. 489, and in the supported joint but 
 one. 
 
 Spike slots in the rails are not admissible, as they prevent 
 the full expansion and contraction of the rails. 
 
 RAILS. 
 
 1607. Care in Unloading Steel. — Rails are often 
 bent in consequence of careless handling. There is no ex- 
 cuse for either foremen or workmen for this. The rails are 
 unfit for laying until straightened, but they are often laid 
 in a bent state, giving a bad surface and line. The surest 
 remedy is proper Jiandling. The rails are always loaded 
 properly at the rolling mill, and the kinks are put in them 
 either in transfer or in delivering on the grade. When rails 
 are to be transferred from one car to another, rails of suit- 
 able length should be used as skids upon which the rails to 
 be transferred are pushed from one car to another. When 
 from scarcity of flat cars, rails are shipped in box cars, 
 rollers are placed in the end doors of the box car, and the 
 rails are rolled as they are transferred. The rails should 
 always be placed in regular order, as shown in Fig. 492. 
 
 hmPs^ 
 
 Fig. 492. 
 
 Fig. 493. 
 
 In unloading, there should be enough men to handle the 
 rails with ease and dispatch. The rail should be lifted clear 
 
TRACK WORK. 1039 
 
 of the car floor and carried to the edge of the car. All 
 should be ready, and at the word, the rail dropped clear of 
 the car so that it will fall in the position shown in Fig. 493, 
 in which position the danger of kinking is entirely avoided. 
 Other men should stand on the ground removing each rail 
 as soon as it drops, so that one rail shall not fall on top of 
 another. Rails must not be dropped from the cars on rock 
 or loose stones, but on dirt, which will insure their safety. 
 
 None but the best men should be employed on the steel 
 car. They should be strong physically, understand plain 
 English thoroughly, and be prompt and active. When 
 men, because of difference of nationality, fail to readily 
 understand each other, confusion is sure and accident 
 almost certain to follow. The same gang of men should 
 handle all the steel. If the track laying is to be rushed, at 
 least two, and better three, steel cars should be provided, 
 which permits of one being constantly at the front. As 
 soon as a load of steel is transferred from the flat car to the 
 steel car, a team of horses should be hitched to it and the 
 car hauled to the front. The steel men at the front, having 
 unloaded their car, return with it until they meet the loaded 
 car. They then lift their empty car from the rails to the 
 side of the track, allowing the loaded car to pass. The 
 steel men push the loaded car the balance of the way unless 
 the grade is heavy enough to require a team. 
 
 Steel cars should be light and strong, and capable of 
 carrying a heavy load. The car should be of such weight 
 as to be readily handled by the steel crew. The wheel base 
 should be 8 inches in width, so that the car may pass safely 
 over rough and poorly gauged track. 
 
 1608. Straightening Rails. — If from any cause, 
 rails should be bent, they should be carefully straightened 
 
 A 
 
 Fig. 49^. 
 
 before being placed in the track. If kinked, i. e., bent lat- 
 erally as shown in Fig. 494, they may be straightened by 
 
1040 
 
 TRACK WORK. 
 
 nicking the flange of the rail with a cold chisel on the con- 
 vex side of the rail at the point A where the bend is the 
 sharpest. Then, laying the rail on its base, a few sharp 
 blows with a sledge on the side of the head of the rail at 
 the point A will remove the kink. Kinks may also be 
 removed by means of a rail bender or Jim crow, shown 
 in Fig. 495. The jim crow consists of two heavy hooks 
 
 Fig. 495. 
 
 a and d, which fit over the head of the rail. The curved 
 barV, which unites these hooks, is drilled at its crown, and 
 threaded to receive the screw d. The cross-bar i- unites with 
 the two hooks a and d, and serves as a guide to the screw c/. 
 Force is applied to the screw by means of the wrench /y 
 having a long handle. 
 
 If surface-bent, as shown at A in Fig. 496, they are easiest 
 
 Fig. 496. 
 
 Straightened with the jim crow. The straightening of 
 the rails befoi;e laying will avail but little unless the ties are 
 
TRACK WORK. 
 
 1041 
 
 well bedded, and all of the rails given a good bearing when 
 the track is laid. 
 
 1609. Curved Rails. — Rails laid on curves should 
 always be curved before being placed in the track. When 
 laying track on new road, it is a much better policy to curve 
 the rails in the material yard before forwarding to the track- 
 layers. The material foreman should have a list of the 
 curves in the same order in which they occur in the track. 
 He should be able to determine the middle and quarter 
 ordinates of a 30-ft. rail for any degree of curve, and should 
 curve each rail accordingly. His list 
 of curves will give the station of the 
 P. C. and P. T. of each, from which 
 he will determine the length of each 
 curve and the number and length of 
 rails required for each. These rails 
 should be marked with the number of 
 the degree of the curve for which they 
 are intended, and the rails for each 
 curve should be kept separate from the 
 other rails by pieces of board, so as to 
 prevent any confusion when they ar- 
 rive at the front. One 29|-foot rail is 
 laid for each 6° of angle in the curve; 
 hence, for a curve with a central angle 
 of 30°, the number of 29|-ft. rails re- 
 
 • J • 30 . 
 quired is — = o. 
 6 
 
 In laying the track, 
 
 the short rails should be equally dis- 
 tributed throughout the curve. The 
 rails are curved either with a rail ben- 
 der, shown in Fig. 495, or by the aid 
 of a track lever and curving hook, 
 shown in Fig. 497. 
 
 The latter process is as follows : A fig, 4»7. 
 
 tie A is placed under each end of the rail B which is to 
 be curved. A hook C is placed under the main track rail 
 
1042 
 
 TRACK WORK. 
 
 between two ties, at about 6 feet from the end of the 
 rail to be curved. The track lever D is then let into 
 the hook C^ and the men pry down upon the rail B, 
 giving it the required curve. The quarter points should 
 always be curved before the center, as it often happens that 
 the center curves with the quarter points, thus saving time. 
 The practice of curving rails by dropping them across 
 two ties, or pounding them with a sledge hammer, can not 
 be too severely condemned. By the former method, an 
 angle instead of a curve is often put in the rail, and sledging 
 is liable to break a rail outright, or, at least, put a flaw 
 in it which may result in actual fracture when laid in the 
 track. Some of the worst accidents on record have been 
 caused by broken rails, weakened by hard usage while being 
 curved. The following table contains a list of curves and 
 tangents and the number and lengths of rails required for 
 each. With such a list, the material foreman can forward 
 the rails curved and assorted. His facilities for curving 
 rails should be of the best, and with a skilled gang of 
 men he can turn off much more and better work than 
 would be possible at the front : 
 
 MATERIAL FOREMAN'S LIST OF RAILS. 
 
 
 
 
 No. of 
 
 No. of 
 
 
 Station. 
 
 Deg. 
 Curve. 
 
 Central 
 Angle. 
 
 30-Ft. 
 Rails Re- 
 quired. 
 
 29i-Ft. 
 Rails Re- 
 quired. 
 
 Remarks. 
 
 40 + 90 
 
 
 
 
 
 End of track. 
 
 25 -f 50 
 
 P. T. 
 
 43° 12' 
 
 29 
 
 7 
 
 
 20 + 10 
 
 P. C. 8° L. 
 
 
 
 
 
 o 
 
 
 
 35 
 
 
 
 14 + 80 
 
 P. T. 
 
 
 
 
 
 10+ 60 
 
 P. C. G^ R, 
 
 25° 12' 
 
 24 
 
 4 
 
 
 1610. Assorting Rail Lengttis. — Rails of different 
 lengths should never be laid promiscuously. The short 
 
TRACK WORK. 1043 
 
 rails should be piled by themselves in the supply yard and 
 forwarded to the track-layers in such order and numbers as 
 they may require. On curves, as the inner rail forms a 
 smaller circle than the outer rail, it is sure to gain, and to 
 maintain the joints in the same relative position, this gain 
 must be compensated by the use of short rails. A list of 
 the curves and the number of short rails required for each 
 should be given to the supply foreman, whose business it is 
 to forward the track material in the order named on the 
 list. This table shows how the material foreman makes out 
 his list. 
 
 EXPANSION AND CONTRACTION. 
 
 1611. In laying track, provision must be made for 
 expansion and contraction of the rails, due to changes of 
 temperature. As the temperature rises the rail lengthens, 
 and unless sufficient space is left between the ends of the 
 rails to allow for the expansion, the ends of the rails abut 
 one against another with such force as to cause the rails to 
 kink or buckle, marring the appearance of the track and 
 rendering it unsafe for trains, especially those running at 
 high speeds. If, on the other hand, too much space is left 
 between the rails, the contraction or shortening of the rails 
 due to severe cold may do equally great harm by shearing off 
 the bolts from the splice bars, leaving the joints loose and 
 unprotected. The coefficient of expansion, i. e., the amount 
 of the change in the length of an iron bar due to an increase 
 or decrease of 1° F. is taken at .00000686 per degree per unit 
 of length. 
 
 Example. — If an iron rod measures 30.015 ft. at a temperature of 
 90°, what is its normal length, assuming 60° as the normal tempera- 
 ture ? The temperature of the bar must be 90' — 60° = 30° above the 
 normal temperature. 
 
 Solution.— As the increase in length is .00000686 ft. per degree for 
 each foot in length of the bar, the total increase for 1 foot of the bar 
 due to a rise of 30' in temperature is .00000686 X 30 = .0002058 ft., and 
 for 30 ft. the increase in length above the normal is .0002058 X 30 =^ 
 ,006174 ft , or about -^^ of an inch. As the rail at a temperature of 90 
 
1044 
 
 TRACK WORK. 
 
 measures 30.015 ft., of which length .00617 ft, say, .006 ft., is due to 
 expansion, the normal length of the rail is 30.015 — .006 = 30.009 ft. 
 
 Ans. 
 
 To provide against the effects of expansion, an opening 
 is left between the ends of the rails, and to provide against 
 contraction, the holes in both rail and splice bar are made 
 oblong, allowing about ^ inch for extreme movement. The 
 following /ab/e of expansion is a safe guide to track-layers 
 for most latitudes in the temperate zones: 
 
 TABLE 31. 
 
 Temperature 
 When Laying Track. 
 
 At 90° above zero 
 At 70° above zero 
 At 50° above zero 
 At 30° above zero 
 At 10° above zero 
 At 10° below zero 
 
 Space to be Left 
 Between Ends of Rails. 
 
 1 
 
 T15" 
 
 i 
 
 3 
 
 i 
 
 6 
 T6 
 
 of an inch 
 of an inch 
 of an 
 of an 
 of an inch 
 of an inch 
 
 nch. 
 nch. 
 
 To give to the track the proper opening at the joints, 
 expansion shims are used. They are made of iron, and 
 are of various forms. A simple and effective shim is made 
 by bending a piece of ^-inch iron into the form of a right 
 angle, as shown in Fig. 498. This gives a combination 
 
 shim of two thicknesses, 
 viz., y^^ and | inches. 
 After the angle is formed, 
 the Y^g-inch shim is ob- 
 tained by hammering 
 the ^-inch bar to the re- 
 Fi«-498. quired thickness. The 
 
 thickness of each shim should be clearly stamped upon it. 
 When put in place, the shim reaches the full depth of the 
 head of the rail, and the bent portion lies flat on the top of the 
 rail. The shims should not be removed until the joint is 
 
TRACK WORK. 
 
 1045 
 
 full bolted, and there should be a sufficient number of them 
 on hand to keep the track-layers constantly employed, and 
 not require them to wait until shims can be removed from 
 bolted joints. 
 
 SPIKING RAILS. 
 
 1612. There is no part of the track laying more likely 
 to sujffer from carelessness than the spiking. A spike, to 
 be driven properly, should be started in a really vertical 
 position. The spikes at the joints, centers, and quarters of 
 the rail should be driven first. The right-hand rail is usual- 
 ly spiked first. The gauge is then placed on the fixed rail, 
 and the free one brought to the gauge and spiked. 
 
 The common and slovenly custom of driving spikes at an 
 angle should not be tolerated. An almost equally pernic- 
 ious custom is to drive the spike with the track at loose 
 gauge and then bending the head so as to give the rails their 
 proper gauge. 
 
 First see to it that the free rail is brought to the gauge. 
 Then start the inside spike a little removed from the base 
 of the rail, the head inclined slightly backwards. Having 
 started the spike, a good blow will bring it to a vertical 
 position, after which the blows should be delivered vertically 
 upon the head. The last blow should slightly draw the head 
 towards the rail base. AVhere the gauge is widened on curves, 
 a special gauge should be provided and the eye not trusted 
 to give the proper increase in gauge. Spikes should not be 
 driven in the middle of the tie, especially in severe freez- 
 ing weather, as they are 
 liable to split it, but at 
 from 2^ to 3 inches from 
 the outside of the tie, 
 where the wood is sure to 
 be sound and the grain less 
 open. 
 
 The proper arrangement 
 of the spikes in the tie is 
 show.n in Fig. 499. Ties spiked in this fashion can not 
 
 Fig. 499. 
 
1046 
 
 TRACK WORK. 
 
 become skewed, and the track, in consequence, thrown out 
 of gauge. 
 
 In spiking, the tie must be held firmly against the base 
 of the rail. If from any cause the rail does not lie directly 
 
 Fig. 500. 
 
 upon the tie, the tie must be held against the rail with a 
 nipping bar, shown in Fig. 500. 
 
 The ends of the ties should be spaced at a uniform distance 
 from the rail, both for the sake of appearance and to give 
 to the rail a uniform foundation. A gauge made of hard 
 wood and meeting this requirement is shown at A and B in 
 Fig. 501. 
 
 The spiker first places the gauge upon the tie with its 
 head close against the end of the tie, as shown at A. The 
 
 Pig. 501. 
 
 base of the rail is then brought against the end of the gauge 
 and the inside spike started. The gauge is then removed 
 and the outer spike started, and both driven home. The 
 other rail being spiked to a proper gauge will make the rails 
 equidistant from the ends of the ties. The gauging of the 
 ties is too often done by guesswork, as is evinced by a 
 ragged line. 
 
 1613. Spiking Bridge Ties.— Holes should be bored 
 in bridge ties to receive the spikes instead of driving the 
 
TRACK WORK. 1047 
 
 spikes directly into the tie. As bridge ties are sawed, they 
 are often cross-grained and liable to split unless holes are 
 bored for the spikes. The diameter of the spike holes should 
 be about ^^ inch less than the diameter of the spike, so that; 
 in driving, the hole will be completely filled with the fiber of 
 the wood. 
 
 1614. Pulling Spikes. — When a spike is to be drawn 
 from a tie in frosty weather, or from an oak tie at any time 
 of year, it should always be given a light blow with a spike 
 maul before using the claw bar. The blow breaks the hold 
 which the wood has upon the spike, and permits of the spike 
 being drawn with safety. Without this precaution the 
 spike is liable to break off under the head. The instrument 
 for drawing spikes is called a cla-w bar, and is shown in 
 Fig. 503. Its weight is about 25 lb. The end a of the claw 
 
 Fig. 502. 
 
 bar is divided like the claw of a carpenter's hammer and the , 
 bar bent into a goose-neck to increase the distance through 
 which the opposite end b can move. In drawing a spike 
 care should be taken that the claw is well under the spike- 
 head before a strain is put upon the bar. When only the 
 lip of the claw is under the head, there is great danger of 
 the claw being broken, especially if a heavy stress is put 
 upon it. When the spike is driven so deeply into the tie 
 that the claw can not be forced under it, the end b of the 
 claw bar, which is wedge-shaped, may be forced under the 
 spike-head, lifting it so the claw may be used. 
 
 1615. Gauging Tracl«. — In track laying, no part of 
 the work should receive more careful attention than the 
 gauging of the track. A track gauge, to be in proper 
 position, must be at right angles to the center line of the 
 
1048 TRACK WORK. 
 
 track, and with this fact in view the gauge shown in Fig. 
 503 was devised. The gauge consists of two U-shaped cast- 
 ings connected bv a short iron pipe which is threaded at 
 both ends, and screws into them. The castings have lugs 
 on their under sides, as shown at A and B. The distance 
 A B between the lugs determines the gauge. A line drawn 
 across the faces of the gauge lugs is at right angles to a 
 line drawn through the center of the iron pipe. To place 
 the gauge at right angles to the center line of the track, 
 bring both lugs shown at C against the head of the rail. A 
 notch filed in the gauge at D marks the center of the track. 
 
 G 
 
 ^ ^ h ~'^ *^£' 
 
 3 C 
 
 Fig. 503. 
 
 Never crowd the gauge in spiking the rails. Let the rails 
 only touch the gauge marks. Place the gauge about eight 
 inches ahead of the tie to be spiked. This places the gauge 
 out of danger of the spiking hammers, and insures a perfect 
 gauge. 
 
 SURFACING TRACK. 
 
 1616. As soon as the track is full bolted and spiked, it 
 is put into surface. This is an easy matter where the tics 
 have been bedded to grade, an3 requires much less material 
 than where they have been placed upon the roadway and 
 the rails spiked to them without any attempt at grade. If 
 the track is to be earth ballasted, the material is taken 
 from the shoulder of the roadway. If cinders, gravel, or 
 broken stone is to serve as ballast, construction trains 
 should furnish the material as fast as it is needed. 
 
 Ordinarily, earth is used on new lines, as the finances of 
 
TRACK WORK. 1049 
 
 the company seldom warrant the use of costlier material. 
 ^_^ T) It is only on prairie lines that sufficient ma- 
 
 %Jw terial can be borrowed from the roadway 
 
 IK to put the track in permanent surface, but 
 
 ilNS in most cases enough is available to place 
 
 Fig. 504. 
 
 the track in safe condition for the full 
 operation of the construction train. 
 The tools used in surfacing are the 
 fc track jack, shovel, and tamping bar. 
 ^ The track jack, which takes the place 
 of the ancient track lever, is one of the 
 most economical and indispensable oi 
 the trackman's tools. One of the best track jacks on the 
 market is that made by Joyce, Gridland & Co., of Canton, 
 Ohio, and is shown in Fig. 504. 
 
 This jack is simply and strongly made. The foot A of 
 the jack is placed between the ties with the lug B under the 
 rail. By means of the lever C the toothed bar D is raised. 
 The lug B forms a part of the bar D, the two forming one 
 casting, and, consequently, in moving together, carry the 
 rail with them. A tripper £ is so arranged that if desired 
 the bar D may be made to drop instantaneously. In using 
 the jack it should always be placed on the outside of the rail 
 with the lever pointing from the track. Numerous acci- 
 dents have been caused by misplaced track jacks, some of 
 them entailing great loss of life and property. 
 
 The track is raised to grade with the jack, and the ma- 
 terial deposited with the shovel. Many trackmen use 
 only the shovel blade in surfacing track for the first time, 
 and this is probably the wiser policy, as the prime object of 
 the first surfacing is to make the track safe for the 
 
1050 . TRACK WORK. 
 
 construction train, and any work which unnecessarily delays 
 the construction train is manifestly unwise. There should 
 be no confusion in the work as a result of changing work. 
 Each man should be assigned to his special work and 
 required to do it. 
 
 1617. Lining Track. — As soon as the track has a 
 safe surface, it must be brought to line. This is done with 
 lining bars, shown in Fig. 505. 
 
 In lining, the trackmen with bars are placed at the joints, 
 quarters, and centers of the rails nearest a center stake. 
 
 <■ « • m \\ 
 
 < y 
 
 Weight, 27\(i lb. 
 Fig. 505. 
 
 The foreman places the gauge on the track at the center stake 
 and orders the track thrown until the center mark on the 
 gauge coincides with the tack in the center stake. He then 
 moves his men to another center stake and repeats the 
 operation. Having placed the track on center at the 
 stakes for 300 or 400 feet, he lines in the intermediate por- 
 tions by eye. He should then check the line at the center 
 stakes to make sure that the track has not moved while lin- 
 ing the intermediate portions by eye. It is needless to say 
 that if the ties have been laid to a tie line, the track will 
 not require any lining until after the first surfacing. 
 
 1618. Final Surfacing. — After the construction 
 train has run over the track for a few days, the track will 
 show numerous low places, especially at the joints. A sur- 
 facing crew should then go over the line, putting the track 
 in good surface. The material required for the final surfa- 
 cing can be borrowed from the roadway or obtained by 
 widening and ditching the cuts. That required for the 
 track in the cuts is shoveled directly from the ditch into the 
 track, while that required for the embankment should be 
 hauled by the gravel train. This plan is in every way bet- 
 ter than to borrow the material from the embankment. 
 
TRACK WORK. 1051 
 
 The freezing and thawing of the following winter will cause 
 the slopes of most cuts to break and cave, filling the ditches 
 with heavy mud, which must be removed to make the track 
 safe. Hence, the removal of this material for surfacing at 
 the time of track laying is practically clear gain 
 
 In the final surfacing, all ties should be thoroughly tamped. 
 This is best done with the tamping bar shown in Fig. 506. 
 
 Fig. 506. 
 
 An excellent substitute for the tamping bar is the iron- 
 handled shovel, which serves both purposes of the shovel 
 and tamping bar. When using them, the foreman can 
 spread out his forces, giving to each man his share of ties, 
 and thus obtaining equal service from all. When the ties 
 are to be hard tamped, the tamping bar is the tool for 
 effective service. The ballast should be tamped under the 
 tie, throughout the entire length, but hardest at the points 
 directly under the rails, where the load is heaviest. In case 
 the ballast midway between rails is tamped the hardest, 
 there is danger of the ties being broken in two at the middle 
 by a heavy train. This danger is especially great when the 
 ties are of soft wood. 
 
 The object of ballasting track is not only to secure a firm 
 foundation for the ties, but to so bed them that the track 
 shall not be thrown out of line by the lateral thrust of pass- 
 ing trains. That mode of ballasting is best which most com- 
 pletely beds the ties and at the same time provides for the 
 prompt removal of all water which falls upon the roadbed. 
 
 In filling in the track the material should be deposited in 
 the middle of the track and not against the rails. It should 
 be raised to a height of about 2^ inches above the ties at 
 their middle point A (see Fig. 507), and sloped towards the 
 ends of the ties. Its surface at the inside line B of the rails 
 should be such as to permit the shovel to be passed freely 
 underneath the rail between the ties, and the slope 
 
1052 
 
 TRACK WORK. 
 
 continued to the end of the tie where it should just meet the 
 base of the tie. Outside of the ties, the shoulder CD should 
 continue at a slope of 1^ inches to the foot to the edge of 
 the embankment. 
 
 This insures complete drainage. Rain falling upon the 
 
 roadway will run off before it can penetrate the ground. 
 
 \k 8-0' 
 
 Fig. 507. 
 
 Provision must be made for conducting this surface water 
 into natural channels. This is accomplished by means of 
 side ditches. 
 
 DRAINAGE. 
 
 1619. Ditching and Ballasting. — All railroad man- 
 agers and operators are united in their estimate of the im- 
 portance of thorough drainage. This can be effected only 
 by a thorough system of drains and ditches. These should 
 be of such number and size that they will not only meet the 
 requirements of an ordinary rainfall, but also of the heaviest 
 freshets. 
 
 Ditches are of two kinds, viz., side ditches, those excava- 
 ted in cuts on both sides of the roadway, and surface ditches, 
 those excavated above the slope of cuts to prevent the slope 
 from being washed down. Side ditches are partially made 
 during the grading of the roadway; surface ditches should 
 always be completed during construction, as they are of the 
 first importance in affording protection to the slopes against 
 the floods of surface water which invariably accompany a 
 heavy freshet. The water which, during a heavy shower, 
 falls upon the side slopes and track, is about all that ordinary 
 side ditches can accommodate; and if the protection of sur- 
 face ditches is lacking, great quantities of surface water are 
 
TRACK WORK. 1053 
 
 discharged at different points directly upon the unprotected 
 slopes, soaking the roadbed, carrying with it quantities of 
 earth and gravel which choke the side ditches, and, where the 
 quantity of water is sufficient, producing a washout. In fact, 
 the surface ditch is indispensable to a newly constructed 
 road, and the question of its construction should not be open 
 to debate. 
 
 As stated above, the side ditches are partially made during 
 the grading of the roadway, and their completion deferred 
 until the ballasting and final surfacing of the track. All the 
 material excavated in completing the ditching should be used 
 in surfacing the track, and any additional material required 
 should be obtained by widening the cuts. 
 
 Wet, springy cuts are a serious annoyance and expense to 
 any railroad, especially where the widths of roadways and 
 slopes are limited by a fixed standard. A cut whose width 
 and slopes are ample for sand or gravel is totally inadequate 
 for clay. Springs in the bottom of the cut keep it constantly 
 wet, and a firm track is impossible. Frost and rain cause the 
 slopes to cave, filling up the ditches and often covering the 
 ties from sight. Such a track will be full of sags in summer 
 and badly heaved in winter, and at no time safe for trains at 
 high speed. There is nothing to be gained from tinkering 
 with and patching up such a track. The permanent cure 
 is in widening the cut and reducing the slopes, so that 
 whatever material caves in will lodge well outside the ditch 
 line. The ditches should be from 8 to 10 feet from the rails, 
 and so deep that the ballast will not be soaked by the water 
 flowing through them. The cost of such work will often be 
 heavy, but it will end the trouble and prevent the further 
 wasting of money in useless tinkering. 
 
 During the construction of the road, the slopes and zvidth 
 of roadivay should, so far as possible, be suited to the charac- 
 ter of the material in which the excavations are made. 
 
 The dotted lines in Fig. 508 show a standard section of a 
 through cut as made during the grading of the line, and the 
 full lines show the section after the track has been laid, the 
 cut widened, the ditches made, and the track ballasted. The 
 
1054 
 
 TRACK WORK. 
 
 material excavated in this work is used for ballasting the 
 track. In establishing the grades for a new line, the com- 
 petent engineer will make provision for the drainage of the 
 cuts. Sometimes the grade is continuous throughout the 
 cut, carrying all the water one way; but where the average 
 grade is level, the drainage is effected by making the grade 
 to ascend from both ends of the cut, uniting them by an easy 
 vertical curve at the middle. 
 
 Where the cut is short, it is a mistake to break the gradient, 
 but rather depend for drainage upon well-constructed ditches. 
 Where the grade of the cut is level, the ditches at the middle 
 of the cut are made shallow, and the depth gradually in- 
 creased towards the ends. The grades of such ditches should 
 
 Fig. 508. 
 
 be given by the engineer, and the excavation made to con- 
 form to those grades. It is the continuous grade which 
 gives to a ditch its full efficiency. Where the grade is a suc- 
 session of levels and sudden drops, the level places accumu- 
 late mud on account of a sluggish current, and the steep 
 places wash badly because of a rapid current ; and in a 
 comparatively short time a new ditch must be made. 
 
 Particular attention should also be paid to the alinement 
 of the ditch. Crooks in the ditch impede the flow of the 
 water and tend to increase the deposit of mud. First 
 determine the line of the ditch, with a view of avoiding any 
 unnecessary excavation, and then cut the ditch to a true line. 
 
 When gravel or broken stone is used for ballast, the section 
 of the roadbed is somewhat altered, although its general 
 dimensions remain the same. As stated in Art. 1603, the 
 ties should not be bedded when cinders, gravel, or stone 
 
TRACK WORK. 
 
 1055 
 
 ballast is to be used. A section of roadway ballasted with 
 either cinders or gravel is shown in Fig. 509. The ballast is 
 filled in between the ties, flush with their tops, and extends 
 to a depth of 8 inches below them, sloping from the outer 
 top edge A of the tie to the edge of the ditch. 
 • On some roads the shoulders at B and C are rounded off, 
 as shown by the \m& D E, before the ballast is deposited. 
 The effect of this is to improve the drainage. 
 
 The ditch extends 12 inches in depth below subgrade; 
 i. e., the line B C. 
 
 The subgrade is the grade line laid down by the en- 
 gineers for the grading of the roadway, and marks the bot- 
 
 FlG. 509. 
 
 toms of cuts and the tops of embankments. The actual 
 Q^rade line marks the elevation of the top of the rail, and is 
 from 15 to 24 inches above subgrade. When gravel or 
 broken stone is used as ballast, the material excavated in 
 ditching the cuts should be loaded on a gravel train and de- 
 posited upon the embankments wherever needed. The more 
 
 Fig. 510. 
 
 material deposited on the embankments the better, as they 
 are bound to cave more or less from the effects of frost and 
 rain, before grass has grown in sufficient quantities to pro- 
 tect them. 
 
 A section of track ballasted with broken stone is shown in 
 
1056 TRACK WORK. 
 
 Fig. 510. The ballast extends from 10 inches below the 
 bottom of the ties to the level of their tops, and is shouldered 
 outwards from the ends of the ties as shown in the figure. 
 The side ditches are 12 inches in depth, the slope of the bal- 
 last and that of the ditch forming practically a straight line. 
 The slopes of the cuts given in Fig. 510, as well as those 
 given in Figs. 508 and 509, are 1 horizontal to 1 vertical 
 This is the steepest slope at which earth will stand. The 
 certain effect of weather is to cause the slope to cave, flat- 
 tening it and at the same time filling up the ditches. In all 
 recent railroad construction, where the finances of the com- 
 pany will permit, the slopes of both cuts and embankments 
 are made the same, viz., 1| horizontal to 1 vertical. Cuts 
 can be widened much more cheaply before than after track- 
 laying, but it is often a difficult question to decide where it 
 is safest to economize. 
 
 The proper time to clean ditches is in the fall, commen- 
 cing about October 1 and finishing by or before November 1. 
 Occasionally the slopes of a cut cave in so badly that ditches 
 require frequent clearing. The only permanent cure is to 
 widen the cut to such an extent that caving material can not 
 encroach upon the ditches and track. Some writers on 
 track insist that there should be no side ditch nearer than 
 10 feet from the rails, nor slopes less than 1^ horizontal 
 to 1 vertical. This would require a roadway at least 
 twenty-four feet in width for a single track, and involve 
 an outlay which would prohibit the building of nearly all 
 new lines. 
 
 The roadway and track sections given in the preceding 
 pages are entirely consistent with moderate expense and 
 thorough construction. When the line is fully equipped, 
 traffic connections established, and business on a paying 
 basis, there will be ample time for betterments and a pros- 
 pect of money with which to pay for them. 
 
 The purpose of all ditches and drains is to convey the 
 water to natural channels and thence out of reach of the 
 track. In Arts. 1461 and 1467, mention was made of 
 the common fault of making culvert openings too small. 
 
TRACK WORK. 1057 
 
 They should be designed to meet the requirements of the 
 severest storms and freshets. At all low places where the 
 water remains standing alongside the track, open culverts 
 should be built, allowing the free passage of the water. 
 Brooks liable to overflow and wash the track should have 
 their channels deepened or their banks raised. After every 
 freshet, all water passages should be thoroughly examined 
 and all obstructions, such as sticks, brushwood, weeds, 
 etc., removed. Brush and weeds not only obstruct the 
 passage of water, but, when dry, are easily ignited by sparks 
 from the engine and are a continual menace to the safety of 
 the track. 
 
 Open passages for water, built of framed timber, are to be 
 condemned. They are likely to be undermined by a freshet, 
 and are at best a cause for anxiety. If stone is not avail- 
 able, the track should be carried on piles. The bents of 
 piles next the embankment should be sheathed up with plank 
 to prevent the washing of the embankment. 
 
 1620. Side Tracks. — The opinion still prevails on 
 some roads that any kind of work or material will answer 
 for a side track. This is entirely wrong. The same skill, 
 work, and materials that go into the main track should be 
 expended upon all side tracks. The tax upon trainmen and 
 rolling stock is always greater on side tracks than on the 
 main line, and it is there that time is either saved or lost. 
 With a good track, shippers can move a loaded car with a 
 team; whereas, if the track is rough, they are compelled to 
 wait for a freight train, which must stop until the car can 
 be shifted. It is admissible to use No. 2 ties in a side track, 
 except that all joint ties should be strictly first-class. Where 
 No. 2 ties are used they should be placed closer together in 
 the track, so as to insure a first-class foundation for the 
 rails. All side tracks should, as far as possible, have a 
 switch at both ends. This permits trains to enter the side 
 track from both directions without passing a switch and 
 backing into the siding; it also effects a saving of time, 
 labor, and fuel. 
 
1058 TRACK WORK. 
 
 CARE AND MAINTENANCE OF TRACK. 
 
 SPRING TRACK WORK. 
 
 1621. At the first break up of winter the spring track 
 work begins. The section foreman should plan his work so 
 as to take advantage of each day as the season advances. 
 As soon as the snow has disappeared from the track, which 
 will always be a "few days earlier than from less exposed 
 places, he should set his men to work at cleaning up the 
 station grounds and yard. All scattering track material 
 should be collected and neatly piled at a place convenient to 
 the hand-car house. All rubbish which may have accumulated 
 during the winter must be removed and used either to fill up 
 low places in the right of way, or burned, if necessary. 
 
 All switches should be thoroughly repaired and put in per- 
 fect line. Battered rails should be replaced by good ones; 
 guard-rails and frogs examined and defects in them rem- 
 edied, and all ties collected, loaded on cars, and distributed 
 along the section, where they will be ready at hand when 
 needed to put in the track. All breaks in fences should be 
 repaired at the earliest opportunity. The approaches to 
 highway crossings should be made safe, and everything done 
 in the way of repairs which the season will permit of. As 
 the frost begins to leave the track, settlement commences, 
 and the track should be carefully watched, thick shims being 
 replaced by thinner ones as the settlement goes on, and all 
 shims removed as soon as it is possible to spike the rails to 
 their proper surface. 
 
 Every joint throughout the section should be examined; 
 all loose bolts tightened ; nut-locks or washers supplied 
 where needed, and broken bolts replaced by new ones. As 
 the frost leaves the track, especially in wet cuts, soft places 
 will appear. These must be reported to the train dispatcher 
 at once. By keeping the side ditches clear and deepening 
 them as the frost leaves the ground, soft places can usually 
 be made safe until the ground settles, when thorough re- 
 pairs should be made. If the place becomes dangerous the fact 
 
TRACK WORK. 1059 
 
 must be reported by telegraph to the roadmaster, who will fur- 
 nish the necessary men and materials to make the track safe. 
 
 1622. Washouts. — The melting snow together with 
 the spring rains greatly increase the volume of surface 
 water, and as the frost comes out of the ground but slowly, 
 ditches and natural water channels are taxed to their utmost 
 capacity. It is at this season of the year that washouts and 
 landslides are chiefly to be feared. All ditches, culverts, and 
 bridges must be kept clear of obstructions, and the track 
 watched night and day so long as danger is to be appre- 
 hended. In case of a severe storm, the section foreman 
 should send a responsible man to one end of the section with 
 the proper signals to stop trains in case of danger, while he 
 goes to the other end of the section, leaving a man to guard 
 any dangerous spot until the section is entirely covered. In 
 case he laches the means to repair any damage done, he must 
 report the fact by telegraph to both the train dispatcher and 
 roadmaster, in order that the former may hold trains at 
 convenient points while the latter can rush a construction 
 train through to the point of danger. The foreman should 
 include in his report the location of the break or washout, 
 the number of the bridge or culvert, the length of thebreak,^ 
 the number of missing bents, and any information which 
 will aid the roadmaster in making a Correct estimate of the 
 men and materials necessary to repair the damage. He can 
 then set to work with his men, making such repairs as his 
 limited force will permit of, and being ready to render every 
 assistance in his power to the roadmaster, who assumes 
 charge on his arrival. A foreman should never attempt any 
 repairs of track until he has inspected his entire section, as 
 two or more breaks may occur simultaneously, and while re- 
 pairing one break an accident is liable to occur at another. 
 
 1623. Repairs of Track. — As soon as the frost has 
 left the track and all shims have been removed, bringing 
 the rails down to the surface of the ties, the section foreman 
 should go rapidly over his section, making such repairs as 
 will render the track safe and reasonably smooth. If the 
 
1060 TRACK WORK. 
 
 track is well ballasted with gravel or broken stone these re- 
 pairs will be quickly made, as such track will hold a good 
 line and surface after the severest winter. If, however, the 
 ballast is clay, the track will show many low places and an 
 uneven line. The track jack, shovels, and picks are all the 
 tools needed for the first repairs. A man is set to dig block 
 holes for the jack at the lowest points in the sags. The 
 track is then raised until it is in average surface with the 
 track at either end of the sag. Dirt is then shoveled under 
 the ties, care being taken to throw it well back to the middle 
 of the tie. No attempt should be made to tamp the ties other 
 than to fill up the cavities formed by raising them. A part 
 of the force will follow, dressing up the track and filling 
 block holes. The foreman should stop raising track about two 
 hours before quitting time, taking with him sufficient hands 
 to line up and gauge the track surfaced during the day. 
 The line side of the track is then given a perfect line. 
 Either rail may be taken as the line side, but the same rail 
 should always be used for lining. A part of the force take 
 the gauge and spike maul and spike the track to gauge, 
 while the rest follow, dressing up the track. This work will 
 put the track in perfect line and fair surface, and by the time 
 the entire section is covered the ground will be thoroughly 
 settled and the track in shape for permanent surfacing. 
 
 1624. Lining Track. — When lining track the fore- 
 man should stand with his back to the sun and as far from 
 the piece of track which he is to line up as his eyesight will 
 permit. This gives him a better view of the straight 
 portions on each side of the crooked portion, all three of 
 which are to be brought into the same straight line. A 
 simple device, much practiced by trackmen when lining 
 track, is to place small lumps of dirt on the top of the rail 
 to be straightened. These lumps show plainly in contrast 
 to the bright, unbroken surface of the rail, and when 
 brought into range insure a good line. 
 
 With a strong section gang the foreman can readily per- 
 form any of the tasks which confront him ; but when from 
 
TRACK WORK. 1061 
 
 necessity his force is reduced to a minimum, he is obHged to 
 resort to every expedient within his knowledge. He must 
 not only direct the work, but lead in its execution. Fre- 
 quently a foreman will have charge of ten miles of track, 
 and have but four hands besides himself wherewith to main- 
 tain it. It is under such circumstances that ingenuity and 
 energy count at their full value. 
 
 When a sag in the track has caused a crook in the line, and 
 there is not sufficient force to throw the track to line, the 
 following scheme will enable the foreman to straighten the 
 track and hold it in place. He can only straighten one rail 
 length at a time, and-to do that he should remove the spikes 
 from three or four of the ties under the rail. The ties so 
 detached from the rail are called dead ties. The lining 
 bars are then placed under the rail upon the dead ties, which 
 afford a far firmer foundation and leverage than ordinary 
 ground. The track is then thrown to line, after which the 
 dead ties are shifted to their proper position. If the track 
 has a tendency to slip back out of the line, the rails can be 
 temporarily spiked to the dead ties, which, being securely 
 bedded, will hold the rails permanently in place. 
 
 1625. Straining of Track Bolts. — Reference has 
 already been made to this serious fault, which is almost 
 universal among trackmen and generally due to ignorance 
 on their part. The rail splices on most American roads are 
 fitted with nut locks of either metal or fiber, the object of 
 which is to lock the nut and at the same time permit of the 
 expansion and contraction of the rail. In order that expan- 
 sion and contraction may take place, the nut should only be 
 brought to a snug bearing on the nut-lock, whereas, the 
 common practice is to screw on the nuts as far as the strength 
 of the trackman will permit. This places the bolt, nut-lock, 
 and nut under a severe strain, with the result that the rail 
 can not freely expand and contract; the nut-lock is deprived 
 of all power to act, and at the first abrupt change of tem- 
 perature the nuts are liable to snap off on account of the 
 sudden strain. One of the first duties of the section fore- 
 man is to explain to his men the object of the slots in the 
 
10G2 TRACK WORK. 
 
 rails, expansion shims, and nut-locks. In putting in track 
 bolts, first bring the nut to a bearing, after which a half 
 turn with the wrench is sufficient. Track wrenches should 
 not be longer than 16 inches for f-inch bolts. Spike slots 
 should always be made in the angle splice. These prevent 
 the creeping of the rails and at the Same time permit the 
 free expansion and contraction of the rails. 
 
 1626. Removing Old Track Bolts. — In removing 
 old track bolts they should never be battered with either 
 hammer or wrench. The nut should not be entirely re- 
 moved from the bolt until the bolt is loosened in the 
 splice. When the nut is nearly off the bolt, give it a 
 slight tap with the track wrench. This will loosen the bolt 
 without injuring the thread. The thread of the old bolts 
 should be oiled and the nuts well screwed on so that they 
 will be complete and in readiness for service when needed. 
 
 1627. Loose Track Bolts. — Changes of temperature 
 often cause the loosening of track bolts. These are most 
 noticeable in the spring and fall of the year. Trackmen 
 should watch for and promptly tighten all loose track bolts, 
 as they are one of the main causes of low joints. 
 
 1628. Line and Surface of Bridge Approaches. 
 
 — Special care should be taken to make the line and surface 
 of the track on bridge approaches as nearly perfect as pos- 
 sible. Pile bridges are liable to heave, especially when the 
 ice surrounding them is lifted by a spring freshet. Section 
 men should not attempt to repair bridges unless circum- 
 stances require it. They have neither the experience nor 
 tools for such work. 
 
 Bank sills (those resting upon the embankment and 
 supporting bridge stringers) are continually settling, and 
 cause a bump, or lift, in the track at the bridge line. The 
 sills should be raised and kept in perfect surface by hard 
 tamping, and all bank ties kept well tamped. If possible, 
 avoid placing a rail joint over a bank sill. It is almost cer- 
 tain to be low at times; but. rather arrange the track so as 
 to bring the center of the rail at that point. 
 
TRACK WORK. 1063 
 
 SUMMER TRACK WORK. 
 
 1629. General Repairs. — On Northern railroads, 
 general track work commences with the month of May. By 
 that time all frost has left the track and settlement has 
 taken place generally. 
 
 The section foreman should go to the end of his section 
 to commence track repairs, and work towards home, finish- 
 ing as he goes, raising all small sags and low joints to 
 a proper surface, tightening all loose bolts, relining the 
 track, and correcting all defects in gauge. He should fill 
 in the middle of the track and dress it down to the track 
 shoulder. He should allow nothing short of actual com- 
 pulsion to call him from his work until the entire section 
 is covered. He will then be in readiness to put in new 
 ties, lay new steel, surface track, or cut weeds according 
 as the work demands. In going over the track, the fore- 
 man can correctly estimate the number of new ties needed 
 and make early requisition for them in order that they 
 may be on hand when needed. He should keep a record 
 of the places where new ties are needed and distribute them 
 accordingly. 
 
 1630. Track Ties. — Track ties constitute one of the 
 most important items in the initial cost and maintenance of 
 a railroad. The company should provide the best ties 
 within their means, and, if possible, have them well seasoned 
 before being placed in the track. Ties made from logs split 
 in two parts should be laid with the sap side up. This 
 brings the wide or heart side of the tie underneath, which 
 is the position it would naturally take. Pole ties, those 
 made from young trees, are more lasting than those made 
 from large logs, as the older the tree, the more open and 
 brittle the timber. Sawed ties are usually smaller than 
 hewn ties. They are also often cross-grained, and hence 
 more easily broken. Tie specifications should always 
 require uniformity in length and thickness and the removal 
 of all bark. Tie inspectors should strictly enforce these 
 specifications. Tie contractors are quick to note any 
 
1064 TRACK WORK. 
 
 laxness in the enforcement of specifications and always ready 
 to take advantage of it. 
 
 Ties in the roadbed should be not less than 8 feet in 
 length, 7 inches in thickness, and show at least 7 inches of 
 face and be hewn to a uniform thickness throughout their 
 entire length. Winding ties should be promptly rejected. 
 They are dear as a gift. 
 
 The life of a tie depends not only upon the kind and 
 quality of its timber, but also upon the weight of the rails, 
 condition of the roadbed, and much upon the climate. In 
 Northern latitudes, decay is almost entirely suspended dur- 
 ing the late fall and winter months, while in Southern 
 latitudes decay goes on almost uninterruptedly throughout 
 the year. The yellow pine ties of the South are best fitted 
 to withstand the effects of the climate, and when of sound 
 heart timber they are fairly lasting. 
 
 The loss sustained from the use of inferior ties is apparent 
 when one considers the cost of repairs and renewals. A 
 track laid on ties with an average life of 8 years, and cost- 
 ing 60 cents each, is vastly more economical than a track 
 laid on ties with an average life of 5 years and costing 40 
 cents each. The track laid on the more expensive ties will 
 be superior from the start to that laid on cheaper ones, and, 
 besides requiring far less repairs, it will be in good condition 
 when the cheap track must be entirely rebuilt. The break- 
 age of spikes and angle splices is much greater where cheap 
 ties are used, and accidents more frequent and severe. 
 
 1631. Placing New Ties in Traclc. — When renew- 
 ing ties, no more material should be removed from the 
 track than is necessary to allow the new tie to go into its 
 proper place. Where the track is mud ballasted, remove 
 the dirt from the sides and from the ends of the tie to a 
 depth a little below its bed, but without disturbing the bed 
 of the old tie. If two ties side by side need renewal, a 
 single trench between them will serve for removing both. 
 Remove the spikes and spring the rail up from adjoining 
 ties, slipping a spike under it. Then knock an old tie into 
 
TRACK WORK. 1065 
 
 the trench and pull it out. Pull the new tie into the trench 
 from the opposite side of the track and have two men slide 
 it into place, keeping it well up against the rail until it is in 
 place. If the track is low, throw some fine dirt under the 
 tie and spike the tie to the rail. The ballast removed in 
 putting in additional ties should be thrown into the trenches 
 made when removing the first ties. When all the rotten 
 ties are removed from one rail length, fill in and dress the 
 track before beginning on another rail length. If, after the 
 ties are in place, the track proves to be a trifle high, the 
 defect will disappear after the passage of a loaded train. 
 This method of putting in new ties does away with most of 
 the labor of tamping, and the work is better done. A gang 
 can put in from one-quarter to one-third more ties in 
 this way than by any other method, but it is restricted to a 
 mud-ballasted track alone. If the ballast is gravel or 
 broken stone, all new ties must be tamped. The tie must 
 be held up against the rail with a bar while it is spiked, and 
 the ballast thoroughly tamped with a tamping bar. All 
 new ties must be placed square across the track, and if the 
 old ones are too widely spaced, additional ties must be put 
 in the track with selected ones at the joints. Never spring 
 the rails off the ties on stone or gravel-ballasted tracks, as 
 the ballast collects under the base of the rail and prevents 
 its proper bearing upon the ties. 
 
 The prime object of track repairs is to make the track 
 safe, and if some parts of the section are more needy than 
 others, the foreman should first make those places safe and 
 then go ahead with continuous repairs. 
 
 1632. Estimating New Ties for Repairs. — The 
 
 proper time for estimating the number of new ties needed 
 for repairs is in the fall of the year. In the Northern States 
 the winter is the proper season for manufacturing ties, and 
 most tie contracts are let in that season. If the estimates 
 are made up and sent in to the roadmaster in the fall, he 
 can make more favorable contracts and be sure of having a 
 supply when needed. 
 
1066 
 
 TRACK WORK. 
 
 In making his estimate, the foreman should walk over his 
 entire section, testing every tie of which he is in doubt and 
 reporting the actual number needed, and no more. The 
 renewing of ties is one of the great items of cost in the 
 maintenance of a railroad, and a careful foreman can do 
 much towards prolonging their life. 
 
 1 633. Disposition of Old Ties. — All labor spent in 
 handling old ties is unremunerative, but they must be dis- 
 posed of. In sections where timber is scarce they can 
 usually be sold for fuel. If, however, fuel is abundant and 
 cheap, the best way to dispose of them is to burn them. 
 
 1634. Tie Account. — The foreman should keep an 
 accurate tie account, which will show at once the number of 
 ties received, put in the track, and on hand. The following 
 is a good form for tie accounts: 
 
 TIE ACCOUNT FOR ONE YEAR. 
 
 Months. 
 
 Ties Received. 
 
 Ties Put in 
 Track. 
 
 Ties on Hand. 
 
 Hard 
 Ties. 
 
 Soft 
 Ties. 
 
 Hard 
 Ties. 
 
 Soft 
 Ties. 
 
 Hard 
 Ties. 
 
 Soft 
 Ties. 
 
 January 
 
 
 
 
 
 
 
 February. ...... 
 
 March 
 
 1,000 
 800 
 
 400 
 300 
 
 
 
 1,000 
 
 1,800 
 
 1,400 
 
 800 
 
 400 
 
 
 
 700 
 
 April 
 
 400 
 600 
 800 
 
 100 
 400 
 200 
 
 600 
 
 Mav 
 
 
 
 200 
 
 / j 
 
 June 
 
 
 
 Tulv 
 
 
 
 
 
 August 
 
 September 
 
 
 
 
 
 
 
 
 
 
 
 
 
 October 
 
 
 
 
 
 
 
 November 
 
 
 
 
 
 
 
 December 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TRACK WORK. 
 
 1067 
 
 1635. Cutting Weeds. — On all mud-ballasted roads 
 the cutting of weeds is an important item in the cost of 
 track repairs. All weeds within a distance of 3^ feet from 
 the rail should be kept cut clean to the surface of the ground. 
 It is important to prevent their getting an early start; 
 hence, when making track repairs early in the spring the 
 surface of the ground should be shaved over either with a 
 shovel or weed cutter. This will increase the labor of early 
 track repairs, but it will save much subsequent labor and 
 loss of time. 
 
 A heavy growth of weeds seriously checks the speed and 
 efficiency of a train, especially on heavy grades, besides 
 
 FIG. 511. 
 
 promoting decay of ties. For cutting weeds the blades of 
 shovels or weed cutters should be ground to an edge, and a 
 file kept handy for resharpening. The men should be dis- 
 tributed one to each rail length to prevent crowding and 
 insure an equal share of work from each. 
 
 The weed cutter shown in Fig. 511 does inore effective 
 work, and is less severe upon the men than the shovel. 
 
 The handle of the weed cutter is considerably longer and 
 the blade lighter than that of the ordinary track shovel. In 
 using the weed cutter, men are not compelled to keep their 
 backs continually bent as when using the shovel, and they 
 can cover from one-sixth to one-fourth more ground in a 
 
 day. 
 
1068 TRACK WORK. 
 
 1636. Mowing Weeds, Grass, and Brush. — If the 
 
 section force will admit of it, all weeds, grass, and brush 
 should be cut from the right of way. This work should be 
 commenced by July 20th, mowing first the grass and weeds 
 about all wooden structures and burning them as soon as 
 they are dry enough. This forms a barrier against fire, and 
 insures the safety of these structures while burning other 
 brush or weeds along the right of way. If possible, mow 
 the entire right of way, burning the grass and brush as fast 
 as they are dry enough. With the right of way clear of 
 combustible matter there is comparatively small danger of 
 fire being communicated to adjoining property. This as- 
 surance is well worth the cost of the work, and it is well 
 known that by keeping the right of way clear of weeds and 
 brush, grass is induced to grow, which is far easier to keep 
 in order than brush or weeds. 
 
 ^^ORK ON OLD TRACK. 
 
 1 637. Combination Ballast. — A track can be better 
 ballasted with a combination of stone and gravel than with 
 either of these materialsseparately. Each material has ad- 
 vantages peculiar to itself. Stone is more solid, more open, 
 and heavier than gravel, and, hence, better suited to form 
 the foundation of the track where solidity and drainage are 
 of first importance. Gravel is more abundant, more elastic, 
 and much easier handled than stone. It does not wear the 
 ties, rails, and rolling stock like stone, and is comparatively 
 free from weeds, and, hence, is well suited to form the top 
 course of ballast. Where stone is used only for the founda- 
 tion of the ballast, it need not be broken so finely as when 
 composing the entire roadbed. 
 
 Two carloads of gravel to a 30-foot rail length will make 
 a first-class track where there is a foundation of stone 
 12 inches in depth. 
 
 1638. Preparing Old Track for Ballasting:. — 
 
 When old track is to be newly ballasted with stone, gravel, 
 or cinders, all dirt should be removed from between and from 
 the ends of the ties down to the base of ties and placed on 
 
TRACK WORK. 1069 
 
 the shoulder of the roadbed. This will considerably 
 strengthen the roadbed and afford a support to the ballast. 
 The engineer should set grade stakes 50 feet apart, giving 
 the elevation of top of rail for the finished track. Where 
 sags occur, if it is intended to fill them, the material 
 necessary for raising the track should be delivered, and the 
 track raised to the required grade before the ballasting is 
 begun. 
 
 1 639. Reserve the Best Ballast for Cuts. — When 
 gravelis, the best available ballast, and that of inferior quality, 
 select the cleanest gravel for the cuts, where drainage is most 
 difficult and the track most affected by tlie frost. All mud 
 ballast removed from the roadbed in cuts should be deposited 
 upon the adjacent embankments, which are constantly being 
 reduced in width by the action of rain and frost. If the bal- 
 last is a mixture of gravel, sand, and loam, it should be 
 raised a full 3 inches above the tie at the center of the track 
 and carried out flush with the tops of the ends of the ties. 
 All gravel beds contain streaks of clear gravel. With a little 
 care and calculation the clean gravel can be loaded on sep- 
 arate cars and the train made up with the selected cars by 
 themselves. The inferior ballast should be unloaded on the 
 embankment and the selected ballast deposited in the adja- 
 cent cuts. Make the track shoulders of equal weight. Track 
 with unequal shoulders is sure to work out of line. 
 
 Embankments should be made at least 14 feet in width at 
 the top before depositing the gravel ballast, and 16 feet in 
 width if the means of the company will permit. With a 
 16-foot embankment there is no loss of ballast from its being 
 crowded over the shoulder. 
 
 1640. Ballast Required for a Mile of Track. — 
 
 Allowing an average length of 33 feet per car, 160 cars will 
 cover 1 mile of track. If the trains average 8 cubic yards 
 per car, they will form a continuous bed 12^ feet in width at 
 bottom, 12 feet in width at top, and 6 inches in thickness. 
 Of this amount it will require about one-half to fill in between 
 the ties and dress the middle of the track. This will leave 
 
1070 TRACK WORK. 
 
 a bed of 3 inches beneath the ties. By unloading two cars 
 in a place, the depth of the ballast under the ties is increased 
 to 8^ inches, which will make a first-class track, providing 
 the subgrade is compact and thoroughly drained. 
 
 Gravel may be loaded at the pit for 75 cents per car, 
 making the cost per mile, 2 cars to a rail length, about $250. 
 Under favorable conditions, gravel can be loaded with a steam 
 excavator for considerably less than the above figures. 
 
 1641. Gravel Pits. — The cost of loading gravel at 
 the pit depends largely upon the manner in which the exca- 
 vation is conducted. The prerequisite for cheap loading is 
 a long, high, and regular working face. In laying out a 
 track to a gravel pit, the ground should be well considered 
 and the track placed so as to meet the above conditions for 
 loading. The switch should be so placed that the turn-out 
 curve is passed before the gravel pit is reached. If the face 
 of the gravel bed is uneven at the start, commence loading 
 at the projecting points and continue until the face is uni- 
 form. With each movement of the track, excavate deeper if 
 the depth of the gravel will permit, and so increase the height 
 of the working face. Gravel is generally overlaid with a 
 layer of earth. This earth mixes with the gravel in loading, 
 and the proportion of earth grows less as the height of the 
 working face increases. The grade of the track should be 
 made as uniform as possible, and the track maintained in 
 such order that an engine may draw a full train load from 
 the pit. Under fair conditions, 10 loaded cars constitute a 
 train. If a steam excavator is being used, there should be 
 enough cars on hand to keep the machine constantly em- 
 ployed. The empty cars should be placed on a spur track, 
 connecting with the track leading to the pit, and shifted by 
 teams as they are needed. When a train of empty cars is 
 returned to the pit, the cars are switched to the spur track, 
 and the loaded train hauled out. 
 
 1642. RalsinR Track. — When raising a track to a 
 surface, the following method is recommended: Take a 
 piece of board 1 by 4 inches and 5 feet in length. Cut two 
 
TRACK WORK. 1071 
 
 notches, each 3 inches deep, to fit over the rails, the space 
 between the notches being equal to the gauge of the track. 
 Place this sighting board at a high place in the track, from 
 8 to 10 rail lengths ahead of the point where you intend to 
 commence track raising. Shim up the sighting board to a 
 perfect level, giving it the same height to which the top of 
 the rail is to be brought in the raising. Then, go to the 
 point where you intend to commence track raising and lift 
 the track to a proper height, bringing both rails to the same 
 level. The spirit level is then laid aside and the intervening 
 track brought to a surface by sighting. When sighting, 
 stand from 50 to 75 feet from the track being raised. Raise 
 and tamp each joint about \ inch higher than the actual 
 surface. In raising, two jacks, a heavy and a light one, 
 should be used, the heavy one to raise the joints, and the 
 light one to raise the centers of the rails. Do not attempt 
 to raise a rail center until the jack is in place at the next 
 joint, and then raise together. This prevents the springing 
 of the rails and insures a smooth surface. 
 
 By sighting in -the rails, a more uniform surface is ob- 
 tained, and the delay occasioned by the repeated use of the 
 spirit level is avoided. When the sighting board is reached, 
 it is removed, and the track brought up to the proper 
 surface by sighting. 
 
 In sighting in a curved track, sight along the inside of 
 the rails. This permits of longer and better sights. The 
 foreman should know the time when each regular train is 
 due, and have the track safe for its passage. This is accom- 
 plished by a run off, extending from the new to the old 
 surface. This should be 30 feet in length for each G inches 
 of difference of elevation between the old and new track 
 surface. 
 
 The amount and quality of work done will depend much 
 upon the organization of the force. A good foreman will 
 soon learn the good points of his men and distribute them 
 accordingly. A gang of 14 or 16 men should be distributed 
 as follows: Two with jacks; two to tamp the ends of the 
 ties; four to tamp the centers, and the remaining men 
 
1072 TRACK WORK. 
 
 equally divided, one-half to be employed in filling in ahead 
 of the tampers and the other half in dressing up the track 
 behind them. By dividing up the men equally, placing one- 
 half the force on each side of the track, competition, both in 
 amount and quality of work, naturally follows. With such 
 an organization, a foreman can effectively employ a force 
 within comparatively small limits, enabling him to give 
 thorough inspection to all work, and to give directions 
 wherever needed. 
 
 In raising track, both sides should be lifted together. 
 The common custom of raising and tamping one side of the 
 track at a time should not be permitted, as ties can not be 
 given a uniform bearing. 
 
 The centers of track ties should not be hard tamped. 
 The greater part of the train load comes upon the ends of 
 the ties, and if their centers are hard tamped there is great 
 danger of the ties being broken, especially if they are sawed 
 ties. The ties should be hard tamped only 18 inches inside 
 the rails. This will insure a firm bed and prevent all danger 
 of breaking. 
 
 Uniformity of work is the secret of a smooth track, and 
 the more alike the men work, the better will be the results. 
 
 1643. Yard Work. — All yard tracks should be uni- 
 formly surfaced throughout their entire length. The grade 
 for all yard tracks should be given by the company's engin- 
 eer, and should practically conform to that of the main line. 
 If possible, yard tracks should be level. Cars are then 
 much more manageable and easier handled. Where the 
 yard and main tracks are of the same level, the main line 
 should be put in perfect surface first. The adjoining yard 
 track may then be given an equal height by a level and 
 straight-edge. In the same way, any number of side tracks 
 can be brought to the level of the main track. It is, how- 
 ever, much the better practice to have all elevations given 
 with an instrument. 
 
 1644. Gravel as a Destroyer of Weeds. — One of 
 
 the great advantages of gravel ballast is the saving in the 
 
TRACK WORK. 1073 
 
 cost of weed cutting. Although ballasting with gravel is a 
 heavy initial expense, the outlay ceases when the work is 
 complete. Weed cutting, on the other hand, is a constant 
 and heavy expense, and one of the great arguments in favor 
 of gravel ballast is that gravel discourages the growth of 
 weeds and thereby saves to the company a large annual ex- 
 pense. A railroad company should commence ballasting 
 with gravel at the earliest possible moment, even though it 
 is done in a fragmentary way, as every rail length of gravel 
 is clear gain. 
 
 1645. A Day's Work.— Two rail lengths, or GO feet 
 of finished track, ballasted and dressed, per man, is con- 
 sidered a fair day's work. Foremen should stop raising 
 track long enough before quitting time to line up, fill in, and 
 dress all the track raised during the day. Track left with- 
 out the ties being filled in and the shoulders properly dressed 
 is easily thrown out of line. A heavy shower falling upon 
 track which has not been properly filled in and dressed is 
 certain to do great injury. In all cases, track should be 
 left in a finished condition. 
 
 FALL TRACK WORK. 
 
 1646. Importance of Fall Work. — On Northern 
 railroads, the prime object of fall track work is to prepare 
 for the ensuing winter. One day's work in the fall expended 
 in intelligent track work is worth an entire week of repairs 
 in winter. The section foreman should lay out his work 
 according to the needs of his section, and, as far as possible, 
 adhere to his program. 
 
 1647. Surfacing and Lining Track. — The most 
 important part of the fall work is the surfacing and lining 
 of track. In addition, the track must be put in perfect 
 gauge and dressed down. 
 
 In dressing the track, give as much strength to the 
 shoulders as the available material will permit. With 
 drainage provided for, the heavier the shoulder, the longer 
 the track will hold its line and withstand frost. 
 
1074 
 
 TRACK WORK. 
 
 1648. Seeding^ and Repairing Embankments. — 
 
 It is the severe frosts of winter, followed by heavy spring 
 and summer rains, which destroy embankments. After a 
 heavy spring freshet, embankments are furrowed with deep 
 gulleys, though the usual effect is the gradual wasting of the 
 slopes. The only protection against these destructive agents 
 is a good sod, and foremen should be supplied with grass 
 seed of suitable variety to seed embankments whenever the 
 conditions are favorable. 
 
 Until embankments are protected by grass they must be 
 repaired from time to time. Narrow embankments give 
 insufficient support to the track, and sags are the result. 
 The fall of the year is the best time to repair embankments. 
 All the material obtained from cleaning ditches, widenmg 
 cuts, or from any other source, should be deposited upon 
 the embankments where there is greatest need of repair. 
 This material the section men can transport on a push car, 
 
 Fig. 612. 
 
 which should be fitted with sideboards so as to carry a full 
 load. A section foreman can do much towards keeping his 
 embankments in proper shape, especially if he be well pro- 
 vided with men. If there are bad sags on his section, he 
 should not attempt to take them out until he knows how 
 much material is required for raising the roadbed to the 
 proper height. He can determine the necessary amount of 
 filling by the following approximate method (see Fig. 512). 
 Drive a stake at C against the rail at the middle point of 
 the sag until its top is on line with the track surface at 
 A and B. Measure the height C D oi the stake above the 
 rail. Multiply one-half the distance A B by the top width 
 of the embankment and by the height C D oi the stake 
 above the rail; divide the product by 27. The quotient is 
 the number of cubic yards of material required. 
 
TRACK WORK. 1075 
 
 Example. — A B is 200 ft., C D \%\ ft., and the top of the embank- 
 ment is 14 ft. in width ; how many cubic yards of material are necessary 
 to take out the sag ? 
 
 Solution. — Number of cubic yards = -5- x 14 x 1 -^ 37 = 52, nearly, 
 Ans. 
 
 A push car with sideboards will carry 1 cubic yard of 
 material. If the men and material are at hand, commence 
 by raising the sag near the middle, extending the raising on 
 both sides until the ends are reached. Raise the track at 
 the middle of the sag about y^ higher than the total depth 
 of the sag, to allow for shrinkage of the material. 
 
 1649. General Repairs. — Carefully examine all 
 joints, tightening loose nuts and renewing bolts where they 
 are broken or stripped of their thread. See that proper pro- 
 vision is made for expansion, and that all ties are full spiked. 
 Rotten ties left over from the work of the previous spring 
 should be replaced with new ones. If new steel is required, 
 see to it that it is laid early in the fall and the track well 
 settled before winter begins. 
 
 Thoroughly repair the right of way and snow fences. 
 The winter season puts all fences to the test, and they 
 should be in thorough repair if they are to do service the 
 following summer. 
 
 1650. Building Ne-w Fence. — Though the spring is 
 the most favorable season of the year for building fence, the 
 more urgent track repairs fully occupy the time of every 
 section man. Consequently, fence building is deferred 
 until the late summer or fall. The one disadvantage to 
 building fence when the season is well advanced is the hard- 
 ness of the ground, which makes the digging of post holes 
 much more laborious than in the early spring, when the 
 ground is soft and yielding. There are, however, the fol- 
 lowing advantages in favor of building fence in the fall 
 season. Posts and lumber are usually much better seasoned 
 in the fall than in the spring; streams are low, and swampy 
 places are either entirely dry or at least accessible. It is 
 
1076 
 
 TRACK WORK. 
 
 important that posts should be peeled and well seasoned be- 
 fore setting; and as they are usually cut in the winter 
 season, by delivering them at the section house in the win- 
 ter or early spring, the section men can peel and pile them 
 on stormy days; they will thus be thoroughly seasoned 
 when needed the following fall. 
 
 The most effective fence js of barb wire with one board at 
 the top, as shown in Fig. 513. Posts are spaced 8 feet between 
 centers and set 2 feet 6 inches into the ground. At intervals 
 of 500 feet on straight lines, and at every angle, braces 
 A B should be built into the fence. The brace is mortised 
 into the post at the top and gained into the post at the bot- 
 tom. The wires are spaced as follows, beginning at the 
 bottom wire, which is 9 inches above the ground : The first 
 
 Fig. 51S. 
 
 and second wires are 9 inches apart ; the second and third, 
 10 inches; the third and fourth, 10 inches apart, and the 
 fourth is spaced 10 inches from tKe top board or rail, which 
 is 6 inches in width. This makes the total height of the 
 fence 4 feet 6 inches, which is a lawful fence in most of the 
 States, and the total length of the posts 7 feet. In laying 
 out a fence, measure from the center line of the track, one- 
 half the width of the right of way, and set a temporary 
 post. Place these posts from 50 to 80 rods apart on tan- 
 gents and from 50 to 100 feet apart on curves. Then stretch 
 a light wire between these posts, with tags at intervals of 
 8 feet for spacing and lining the posts. A man then takes 
 a lining bar and spade and plumbs down from each tag with 
 the bar, making a mark with the point of the bar. He then 
 removes the sod from around the hole made with the bar. 
 
TRACK WORK. 1077 
 
 The hole marks the center of a post and guides the men 
 
 who dig the post holes. The wire is removed while the 
 
 holes are being dug, and replaced to give line for setting the 
 
 posts. The diggers should be provided with a gauge giving 
 
 the proper depth of hole. Those nailing on either boards or 
 
 wire must be provided with a gauge giving top of fence and 
 
 the spacing of each strand of wire. 
 
 A handy gauge for spacing wires is 
 
 shown in Fig. 514. It consists of a 
 
 foot piece of pine 2 feet in length. 
 
 6 inches in width, and 1 inch in 
 
 thickness. Another piece of pine 
 
 3 inches wide and 4 feet 6 inches in 
 
 length, equal to the height of the 
 
 fence, is nailed to the foot piece at 
 
 its middle, as shown in the figure. 
 
 The spacing of each wire from the ...-^ 
 
 1 
 
 .. 
 
 
 
 o 
 
 ^ 
 
 
 
 ?.« 
 
 1 ■ ■ 
 
 ground is marked by a notch cut ^'°- ^''*- 
 
 into the edge of the upright piece. The foot piece, besides 
 giving the height from the average surface of the ground, 
 helps to keep the gauge in an upright position. 
 
 In building the fence described above, judgment should 
 be used in distributing the force if first-rate progress is to 
 be made. With a force of a dozen men, the following dis- 
 tribution is recommended : Two men to lay out the work, 
 four digging holes, three setting posts, and three nailing on 
 boards and stringing wires. 
 
 A wire stretcher is necessary to first-class work and prog- 
 ress, though good work at stretching wire can be done 
 withi a crowbar if sufficient care and strength is used. 
 
 At highway bridges and culverts, the fence usually re- 
 turns to the ends of the abutments. The angles made in 
 the fence by these returns must be thoroughly braced. 
 Effective braces for such returns are shown in Figs. 515 and 
 516. 
 
 In Fig. 515 the angle of the return is 00°, and a brace in 
 each panel abutting on the angle is sufficient, but in Fig. 
 516, where the angle contains 150°, an inside brace is added. 
 
1078 
 
 TRACK WORK. 
 
 This brace abuts against a short post set in the ground to 
 receive the thrust of the brace. 
 
 Braces must be placed at each opening, such as farm and 
 
 Fig. 515. 
 
 Fig. 516. 
 
 road crossings, and at all points where changes in direction 
 require it. 
 
 At streams crossed by pile bridges, it is customary to make 
 a return in the fence on both sides of the stream, and to 
 string the wires across the stream, fastening them to the 
 piles. 
 
 On tangents, and on the outside of curves, place boards 
 and wire on the farmers' side of the posts, but on the inside 
 of curves place them on the track side of the line of posts. 
 
 1651. Material for One Mile of Fence.— It will 
 require 661 posts spaced 8 feet between centers to build one 
 mile of fence. One fence board 16 ft. long, 6 in. wide, and 
 1^ in. thick contains 10 sq. ft. of lumber, and 330, the num- 
 ber of boards required for 1 mile of fence, will contain 
 330 X 10 = 3,300 sq. ft. 
 
 Barb wire, of average weight, weighs 1 lb. per rod of sin- 
 gle wire or 4 lb. per rod of finished fence. Hence, for 1 
 mile, or 320 rods, it will require 320 X 4 = 1,2801b. Adding 
 10 lb. for splices, we have 1,280 + 10 = 1,2901b., the amount 
 of barb wire required for 1 mile of fence. It will require 
 ^ lb. of staples for 1 rod of fence, and for 1 mile, or 320 
 rods, it will require 320X^=40 lb., and we have the 
 followin'T 
 
TRACK WORK. 10l9 
 
 TABLE OF MATERIAL FOR 1 MILE OF FENCE. 
 
 Posts. 
 
 Boards. 
 
 Barb Wire. 
 
 Staples. 
 
 661 
 
 3,300 sq. ft. 
 
 1,290 lb. 
 
 40 lb. 
 
 When barb-wire fences were first introduced, the posts and 
 braces were the only wood material used, but they proved 
 very injurious to live stock, which, failing to see the wire, 
 continually came in hurtful contact with the barbs. This 
 objection is removed by placing a single board for the top 
 rail. This board clearly marks the fence line, and, together 
 with the barb wire, makes the most effective fence known. 
 
 1652. A Day's Work at Fence Building.—From 
 
 12 to 14 rods per man is a fair day's work at fence building, 
 though much depends upon the hardness of the ground, the 
 quality of the work, and the skill and industry of the work- 
 men. Fence building requires intelligent industry. A 
 poorly built fence is little better than no fence. 
 
 1653. Distributing Emergency Material. — In the 
 
 late fall, but before any snow falls, place at each mile post, 
 and well up from the ground, a number of rails and joint 
 splices to be used in case of emergency, and known as 
 emergency material. Such supplies are available when 
 most needed, and are constantly near at hand. 
 
 All track material lying about the yard should be collected 
 and piled well off the ground. Piles of ties must be placed 
 far enough apart to avoid catching fire from one another in 
 case of fire. All loose spikes, splices, bolts, and nuts 
 should be collected and placed under covef, and everything 
 about the station made snug and safe for the winter. 
 
 WINTER TRACK WORK. 
 
 1654. General Repairs. — As winter approaches, the 
 
 entire section should be gone over carefully, tightening up 
 
 all loose splices, correcting defects in gauge, and closing up 
 
 joints which the contraction of the rails has left too open. 
 
1080 TRACK WORK. 
 
 The joints of switches are most liable to be open and the rails 
 battered. Close up these joints and renew the rails if neces- 
 sary. See that switch joints, rods, and frogs are in proper or- 
 der, and that guard-rails are properly spaced and well spiked. 
 Keep all spikes driven home, clear the snow from yard 
 tracks and switches, flange out the main track after every 
 snow storm, and remove ice from the ditches. 
 
 1655. Shimming Track. — There is no work con- 
 nected with track repairs requiring more care and judgment 
 than shimming. All mud-ballasted tracks are bound to 
 heave from the action of the frost, and heaving spoils the 
 surface of the track. Inequalities as small as ^ inch should 
 be corrected by shims placed beneath the rail. Shims should 
 be made of hard wood, slightly wedge-shaped, and driven 
 crosswise under the rail. All shims over ^ inch in thick- 
 ness should have a hole bored in them to receive the spike. 
 They are easiest made by boring a hole- through the end of 
 a straight-grained plank and cutting off a piece to the re- 
 quired length, after which the plank may be split into shims 
 of the required thickness. If the rail has cut into the tie, 
 the edges of the groove must be adzed smooth before pla- 
 cing the shims, in order that the rails may have a solid bear- 
 ing. If the track continues to heave, thin shims must be 
 replaced by thicker ones. Where a number of ties side by 
 side require shimming, a plank should be placed lengthwise 
 under the rail and spiked to the ties with boat spikes and 
 track spikes driven through the plank to hold the rail. 
 Where shims exceed 1 inch in thickness, spikes 7 or 8 inches 
 in length should be used. 
 
 For 4-inch shims use 1-inch shims on top of 3-inch plank, 
 and for 5-inch shims, use 5-inch timber. Where shims ex- 
 ceed 1 inch in thickness, old rail splices should be set with 
 one end against the outside of the rail and the other end 
 spiked to the tie to serve as rail braces. These braces 
 should be spiked to every second, third, or fourth tie, 
 according to the height of the shim. 
 
 All high-shimmed track should be closely watched, and 
 
TRACK WORK. 1081 
 
 as the frost leaves the track and the track settles, thinner 
 shims must be substituted for the thick ones. The last 
 shim must not be removed until the frost has left the ground. 
 When the shimmed rail is higher than the rest of the track 
 by the thickness of the shim, you may know that the frost 
 has left the track. All good shims, spikes, and braces 
 should be stored in the tool house, to be in readiness when 
 needed the following winter. 
 
 1 656. Heaved Bridges and Culverts. — Pile bridges 
 and pile culverts require careful watching during the winter 
 season, and whenever they are found to be heaved out of 
 surface or line, the bridge carpenters should be promptly 
 notified. Pile foundations, when heaved by frost, unlike 
 earth foundations, do not resume their original position 
 after the frost has left the track. Neither does the frost 
 affect them equally, as one or two piles in a bent may be 
 heaved out of surface while the others are not stirred. This 
 places the track in a dangerous condition. To remedy the 
 evil, either the track must be shimmed to the surface of the 
 heaved piles or they must be cut down to the original sur- 
 face. Where piles are driven in deep water, the ice should 
 be cut away from them whenever a thaw is imminent, as a 
 sudden rise in the water may lift the body of ice, and the 
 piles, being frozen fast in the ice, must rise also. 
 
 SNOW. 
 1657. Its Prevalence and Effects. — Nearly all 
 roads in the Northern States are obliged to contend with 
 snow, and, in the Northwest especially, the keeping of the 
 track clear of snow constitutes one of the main items of cost 
 of track maintenance. Snow must be contended with in 
 many forms, the most common of which is drifted snow; 
 but it is almost equally difficult to contend with it when it 
 fills the flanges of the rails with ice, or in melting and freez- 
 ing it fills the track ditches and flows across the track, 
 covering the rails with ice and threatening derailment to the 
 first passing train. 
 
1082 TRACK WORK. 
 
 1 658. Snow Keports. — Immediately after every snow 
 storm, the section foreman should ascertain the condition of 
 his track, noting which cuts are clear and which are blocked, 
 and how much snow is in each cut, and the lengths of the 
 drifts. These facts he should report immediately by tele- 
 graph to the roadmaster, in order that preparations may be 
 made to clear the track. If the section is clear of snow, it 
 should be so reported. 
 
 1659. Preparing Track for Snow Plow. — After a 
 storm, as soon as the condition of the section has been re- 
 ported to the roadmaster, the foreman .should take all his 
 force and put his section in shape for the snow plow. In all 
 cuts where the drifts are over two feet in depth, the track 
 should be cleared of snow and flanged out to where the snow 
 has a depth of at least 18 inches, leaving a clean face to the 
 drift. Both ends of the cut should have the same treatment. 
 Snow is most apt to cause derailment when it is of slight 
 depth and hard, and so ground into the flanges that the 
 engines mount the rail. By clearing the track of snow at the 
 commencement and ends of drifts, this danger is avoided. 
 
 1660. Clearing Switches and Flanging Track.— 
 
 As soon as the track is ready for the snow plow, the men 
 should clear the switches of snow from heel of switch to frog, 
 special care being taken to clear the switch rails, rods, and 
 switch stand. The platform, track, and approaches to the 
 station should also be promptly cleared. 
 
 The section foreman should next give his attention to 
 flanging out the main track, beginning near the summits of 
 the hard grades, and at all points where the work upon the 
 engines is most severe. 
 
 1 661 . Clearing Ditclies and Culverts. — If possible, 
 keep the ditches and culverts clear of snow. If, in the fall, a 
 tall stake is driven at both ends of a culvert opening, there 
 will be no trouble in locating it when the culvert is com- 
 pletely covered with drifted snow. By keeping the ditches 
 open, all snow water can run off instead of accumulating 
 and flooding the track, where it is bound to freeze, making 
 
TRACK WORK. 1083 
 
 the track not only hard to operate, but a continual menace to 
 the safety of trains. The ditch for snow water should be 
 fully 6 feet from the rails to insure the safety of the track. 
 
 1662. Snow Fences. — All railroads exposed to severe 
 and repeated snow storms should have some protection 
 against drifting snow. This protection is best provided in 
 the form of fences. Their efficiency will depend upon their 
 strength, height, position, and distance from the track. The 
 fence should be placed at such a distance from the track that, 
 when drifted full, the snow will not reach within 30 feet of 
 the track. To effect this, the distance of the fence from the 
 track should be 12 feet for each foot in height of fence. 
 When the fence is placed too near the track, the snow will be 
 carried to the track before the fence is drifted full ; if, on the 
 other hand, the fence is placed too far from the track, the 
 wind, after clearing the fence, will fall and gather up all 
 the snow between the foot of the drift and the track, and 
 carry it into the cut. Usually but one side of the track re- 
 quires protection from snow, viz., that side from which snow 
 storms most prevail. Most railroads in the snow belt of the 
 United States run in two general directions, viz., east and 
 west, and as most of the severe storms prevail from the north, 
 northwest, and northeast, the north side of most tracks is the 
 only one requiring protection from snow. At some excep- 
 tional points on the line, the topography of the country may 
 cause complex currents of air which may produce results at 
 variance with general rules. At all points, fences should be 
 built to meet the existing conditions. In general, snow fences 
 are built parallel to the track. For fences of ordinary height, 
 the following rule can be safely followed: Place the fence 
 75 feet from the nearest track rail, extending it parallel to 
 the track the entire length of the cut. Change the direction 
 of the fence at both ends of the cut, gradually approaching 
 the track until the ends of the fence are 100 feet from the 
 ends of the cut and 50 or GO feet from the track. 
 
 If the cut ends abruptly at the beginning of a high embank- 
 ment, the turn in the fence must be made before the end of 
 
1084 TRACK WORK. 
 
 the cut is reached, in order to protect the cut from head and 
 quartering winds. Cuts which are lined on the storm side 
 by brush or heavy timber do not require fencing, as the only 
 snow which reaches the track is that which falls directly 
 upon it. The brushwood and timber prevent the blowing of 
 the snow. Cuts made in a side hill where the ground slopes 
 off abruptly into a valley do not require fencing. But where 
 there is a long level or gently rolling stretch of ground on 
 the storm side of the track, the cut is liable to drift full un- 
 less properly fenced. When a fence becomes drifted full, its 
 height may be readily increased by adding a wall of blocks 
 of snow taken from the inside face of the drift. So long as 
 the weather remains cold a snow wall will serve the full 
 purpose of a fence. 
 
 A first-class snow fence, kept in perfect repair, will not 
 last above 10 years, and it becomes a question whether to 
 build a snow fence or grade down the cut so that it will not 
 hold snow. The items of cost to be considered are the first 
 cost of the fence, the annual repairs, the interest on each 
 charge for the time it is to serve in the fence, and if these 
 combined items equal or exceed the cost of grading down 
 the slopes so as to keep the cut clear of snow, the grading 
 should be done. 
 
 1663. Bucking Snow. — The clearing of the track of 
 snow belongs to the Roadmaster's Department, but it is 
 essentially track work and at times of vital importance to a 
 railroad. 
 
 A man should be thoroughly familiar with the best 
 methods of bucking snow before taking charge of an outfit 
 to open up a road for traffic after a blockade. 
 
 Before starting out on the road, he should be as thoroughly 
 informed as possible as to the condition of the road, the 
 location, length, and depth of drifts. He should have strong, 
 live engines and willing engineers. The snow plow should 
 be of the best make and able to throw snow out of a 10-foot 
 cut. There should be two engines in the outfit. The 
 second engine follows closely, with a car, conductor, train 
 
TRACK WORK. 1085 
 
 crew, and shoveling gang. When heavy drifts are encoun- 
 tered too deep for one engine to successfully buck, the 
 second engine is coupled to the first, and besides doubling 
 the momentum, serves to pull out the head engine and plow 
 in case they are stalled. The pilot should be removed from 
 the second engine, and the coupling made short and very 
 strong. No car or caboose should ever be placed between 
 the engines, as they are likely to cause a wreck. When the 
 drifts are more than 10 feet deep, the top of the drift must 
 be shoveled out down to that depth, and a space made 
 wide enough that effective work may be done by the plow. 
 
 When the snow is reported hard, each drift must first be 
 carefully examined and its length and height noted. If the 
 drift has not been faced by section men (that is, shoveled 
 out from the end of the drift to where its depth is from 15 
 to 18 inches), the gang of shovelers must do the work before 
 a run is made with the plow. 
 
 Unless the drifts are properly facedj the plow is liable to 
 mount the rails, especially on curved track, and often the 
 engine is derailed along with the plow. All cars attached 
 to the helper engine shpuld be left behind while bucking 
 snow. If both engines are not necessary to buck a drift, it 
 is better to-do the work with one. The helper engine should 
 only be used where necessary. If the snow is not too hard, 
 a good, heavy engine will clear a drift from 3 to 5 feet deep 
 and from 500 to 800 feet in length at one run. There is 
 comparatively no danger in bucking soft, deep snow with an 
 engine at top speed. 
 
 The engines with a snow-plow outfit should take fuel and 
 water to their utmost capacity at every point reached where 
 a supply can be obtained. Unforeseen delays and mishaps 
 may be encountered, and there must be no risk of a short 
 supply of fuel or water. When the road is badly blockaded, 
 the helper engine should carry an extra carload of coal. 
 The water supply can be readily replenished by shoveling 
 snow into the tank. 
 
 Each engine in the outfit should carry a piece of steam 
 hose, which can be attached to the siphon cock, and reach 
 
1086 TRACK WORK. 
 
 from it to the water hole in the tender. When the water 
 supply needs replenishing, by shoveling snow into the tender 
 and turning on the steam, a tank full of water can be quickly 
 made. The steam hose can also be used to thaw the snow 
 and ice from the machinery and track rails. 
 
 In plowing snow the speed of the engine should always be 
 regulated by the length and depth of the drifts. When the 
 drift is deep and long, the engine should back up far enough 
 to attain full speed before striking the drift. An experienced 
 engineer will so regulate the speed of his engine as to leave 
 but little work for the shovelers. 
 
 The engineer of the plow engine should always sound the 
 whistle when approaching a cut, in order that section men, 
 if working there, may be warned in time to ^et out of the 
 cut. Failure to sound the whistle has been a frequent cause 
 of accident. When it is necessary to buck a drift a second 
 time, the engineer must sound the whistle and be sure that 
 all hands are out of the cut before entering it. It is almost 
 impossible for men to climb up out of a snow cut when first 
 opened up. 
 
 When the snow drift is of such depth and length that two 
 runs are likely to not clear it, it is the better policy to shovel 
 out from both ends until it is certain that two runs will leave 
 a clear track. 
 
 When the snow is both deep and very hard, the crust 
 should be broken up and shoveled out before any attempt is 
 made with the plow. Bucking deep, hard snow with the 
 crust unbroken is very severe work for a locomotive, and is 
 often attended with danger to trainmen. It is far better to 
 insure safety even at the price of delay. It is not advisable 
 to start out to clear a track of snow during a heavy storm, 
 but everything should be in readiness to start the moment 
 the storm abates. 
 
 The invention of the rotary snow plow has practically 
 solved the snow problem, especially for clearing the track of 
 hard snow. Many roads which suffer little from snow do 
 not yet possess rotary plows, and the old custom of bucking 
 snow is still practised when occasion requires it. 
 
TRACK WORK. 1087 
 
 CURVED TRACK. 
 
 1664. Difference in Lengtti of Inner and Outer 
 Rails of a Curve. — It is evident that the radius of the 
 outer rail of a curve is greater than that of the inner rail, 
 and, consequently, its length is greater. This difference 
 may be taken at 1 3V inches per degree of curve per 100 feet, 
 for standard gauge track. The difference in length between 
 the inner and the outer rails of a curve may be found by 
 any of the three following rules : 
 
 Rule 1. — Multiply the degree of the curve by the length 
 in stations of 100 feet, and this prodiict by 1^^ inches. The 
 result will be the difference in length between the inner and 
 outer rails in inches. 
 
 Example. — The degree of a curve is 4° ; its length 520 feet; what is 
 the difference in length between the inner and outer rails of the curve ? 
 
 Solution.— 520 feet = 5.2 stations of 100 feet each. 4 X 5.2 = 20.8. 
 I5V in. = 1.03125 in. 20.8 X 103125 = 21.45 in. = 1.7875 ft. Ans. 
 
 Rule 2. — Multiply the distance between the center lines of 
 the rails by the length of the curve in feet and divide the 
 product by the radius of the track curve. 
 
 Example. — A 4° curve is 520 feet in length ; the distance between 
 the center lines of the rails is 4 ft. 10^ in. ; what is the difference in 
 length between the inner and outer rails of the curve ? 
 
 Solution. — The radius of a 4° curve is 1432.69 ft. (See table of 
 
 Radii and Deflections.) lOi in. reduced to the decimal of a foot is 
 
 „^„ , 4.875 X 520 , ^^ . 
 .87o ft. - ,.^cx nr. = 1- " ft. Ans. 
 1,432.69 
 
 Rule 3. — Multiply the excess for a whole circumference by 
 
 the total number of degrees in the curve, and divide the 
 
 product by S60. The excess of a whole circumference, no 
 
 matter what the degree of curve, is equal to twice the distance 
 
 between rail centers multiplied by 3. II^IQ. 
 
 Example. — A 4° curve is 520 feet in length ; the distance from center 
 to center of the rails is 4 ft. lOi in. ; what is the difference in length 
 between the inner and outer rails of the curve ? 
 
 Solution. — The distance between rail centers is 4.875 ft. 4 875 x 
 2x3.1416 = 30.6306 ft. A 4" curve for 520 ft. contains 20.8°. 30.6306 X 
 20.8-^-360= 1.77 ft. Ans. 
 
1088 TRACK WORK. 
 
 For light curves laid to exact gauge, the first rule is the 
 simpler one, but for short curves where the gauge is widened 
 use either the second or the third method. 
 
 These rules should be applied in determining the number 
 of short rails for curves, when loading material at the sup- 
 ply yard for forwarding to the track layers. As previously 
 stated, a safe rule is one 29^-foot rail per 100 feet for each 
 6 degrees of curvature. In laying track with either even 
 or broken joints, the required number of short rails must be 
 laid in proper order if a first-class job is to be expected.. 
 
 1665. Curving Rails. — When laying track on curves, 
 in order to have a smooth line, the rails themselves must 
 conform to the curve of the center line. To accomplish 
 this the rails must be curved. The curving should be done 
 with a rail bender (see Fig. 495) or with a lever, as shown in 
 Fig. 497. The rail bender is preferable. 
 
 To guide those in charge of this work, a table of middle 
 and quarter ordinates for a 30-foot rail for all degrees of 
 curve should be prepared. 
 
 The accompanying table of middle ordinates for curving 
 rails is calculated by using the formula 
 
 in = ^, (112.) 
 
 in which in is the middle ordinate ; c, the chord, assumed to 
 be of the same length as the rail, and R, the radius of the 
 curve. 
 
 Example. — What is the middle ordinate m of a 30-foot rail for an 
 8° curve ? 
 
 Solution. — The radius of an 8° curve is 716.78 ft. 
 Applying the formula, we have 
 
 ^ = 83r7T6?78= 5773424 = ^■'^' ^'- = '^ '"• ^"^^ 
 The results obtained from this formula are not theoreti- 
 cally correct, yet the error is so small that it may be ignored 
 in practical work. With a table of radii such as is given in 
 the table of Radii and Chord and Tangent Deflections, a 
 table of ordinates may be readily calculated by substituting 
 the known values in formula 112. 
 
TRACK WORK. 
 TABLE 32. 
 
 1089 
 
 MIDDJLB ORDINATES FOR CURVING RAILS. 
 
 
 
 
 Lengths 
 
 of Rails. 
 
 
 
 Degree of 
 
 
 
 
 
 
 
 Curve. 
 
 
 
 
 
 
 
 
 30 Ft. 
 
 28 Ft. 
 
 26 Ft. 
 
 24 Ft. 
 
 23 Ft. 
 
 20 Ft. 
 
 
 In. 
 
 In. 
 
 In. 
 
 In. 
 
 In. 
 
 In. 
 
 1 
 
 oi 
 
 OA 
 
 OtV 
 
 OtV 
 
 Of 
 
 Of 
 
 2 
 
 Oi 
 
 OtV 
 
 Of 
 
 OtV 
 
 Oi 
 
 OtV 
 
 3 
 
 OH 
 
 Of 
 
 OA 
 
 OiV 
 
 Of 
 
 OiV 
 
 4 
 
 OH 
 
 OH 
 
 OH 
 
 Of 
 
 Oi 
 
 OiV 
 
 5 
 
 h\ 
 
 ItV 
 
 Oi 
 
 Of 
 
 Of 
 
 OtV 
 
 6 
 
 ItV 
 
 U 
 
 iiV 
 
 0| 
 
 Of 
 
 Of 
 
 7 
 
 If 
 
 1 rV 
 
 u 
 
 ItV 
 
 Of 
 
 Of 
 
 8 
 
 li 
 
 If 
 
 lA 
 
 ItV 
 
 1 
 
 o| • 
 
 9 
 
 2i 
 
 u 
 
 If 
 
 If 
 
 If 
 
 OH 
 
 10 
 
 2f 
 
 3tV 
 
 If 
 
 U 
 
 li 
 
 lA 
 
 11 
 
 2f 
 
 n 
 
 HI 
 
 iH 
 
 If 
 
 If 
 
 12 
 
 m 
 
 2i 
 
 2i 
 
 iH 
 
 ItV 
 
 U 
 
 13 
 
 3iV 
 
 2H 
 
 2tV 
 
 iH 
 
 If 
 
 If 
 
 14 
 
 3A 
 
 n 
 
 2i 
 
 n 
 
 If 
 
 U 
 
 15 
 
 3^ 
 
 3tV 
 
 2H 
 
 2i 
 
 IH 
 
 iiV 
 
 16 
 
 3f 
 
 3i 
 
 m 
 
 2f 
 
 2iV 
 
 IH 
 
 17 
 
 4 
 
 3i 
 
 3 
 
 9 9 
 
 2iV 
 
 If 
 
 18 
 
 4t\ 
 
 3H 
 
 3A 
 
 2H 
 
 2J, 
 ''T¥ 
 
 11 
 
 19 
 
 4tV 
 
 3J 
 
 3f 
 
 n 
 
 9 ' 
 
 2 
 
 20 
 
 4H 
 
 4i 
 
 3tV 
 
 3 
 
 2tV 
 
 n 
 
 In curving rails, the ordinate is measured by stretching a 
 cord from end to end of the rail against the gauge side, as 
 shown in Fig. 517. Suppose the rail .^ .5 is 30 feet in length, 
 and the curve 8°. Then, by the previous problem, the mid- 
 dle ordinate at a should be IJ inches. To insure a uniform 
 curve to the rails, the ordinates at the quarters d and d' 
 should be tested. In all cases the quarter ordinates should 
 
1090 
 
 TRACK WORK. 
 
 be three-quarters of the middle ordinate. In Fig. 517, if 
 the rail has been properly curved, the quarter ordinates at 
 b and b' will be f X l|in. = l^f, say If in. 
 
 With practice, a man having a good eye and good judg- 
 ment will soon find his eye measurements closely checking 
 his table measurements. When a quantity of rails are to be 
 curved for curves of different degrees, it is a good plan to 
 
 mark the degree of the curve of each rail in white paint on 
 the web of the rail on the concave side. There should be 
 ample force to handle the rails with dispatch, else much time 
 will be wasted. The use of sledges in* curving rails should 
 under no circumstances be allowed. There is great danger 
 of fracture, and often a flaw is caused which at the time is 
 not perceptible, but which may, under the stresses caused 
 by frost and heavy trains at high speed, result in a broken 
 rail, with serious consequences. 
 
 In track work it is often necessary to ascertain the degree 
 of a curve, though no transit is available for measuring it. 
 The following table contains the middle ordinates of a one 
 degree curve for chords of various lengths: 
 
 TABLE 33. 
 
 Length of Chord 
 
 Middle Ordinate 
 
 in Feet. 
 
 of a V Curve. 
 
 20 ft. 
 
 \ in. 
 
 30 ft. 
 
 iin. 
 
 44 ft. 
 
 i in. 
 
 50 ft. 
 
 fin. 
 
 62 ft. 
 
 1 in. 
 
 100 ft. 
 
 2tin. 
 
 120 ft. 
 
 3f in. 
 
TRACK WORK. 1091 
 
 The lengths of the chords are varied so that a longer or 
 shorter chord may be used, according as the curve is regular 
 or not. 
 
 The table is applied as follows: Suppose the middle ordi- 
 nate of a 44-foot chord is 3 inches. We find in the table 
 that the niiddle ordinate of a 44-foot chord of a one-degree 
 curve is ^ inch. Hence, the degree of the given curve is 
 equal to the quotient of 3 -=- ^ = 6° curve. 
 
 Additional examples are given as follows: 
 
 1. The middle ordinate of a 100-foot chord is 14f inches; 
 what is the degree of the curve ? Ans. 5.G°, nearly. 
 
 The degree of the curve is probably 5° 30'. 
 
 2. The middle ordinate of a 50-foot chord is 5^ inches; 
 what is the degree of the curve ? Ans. 8.4°. 
 
 The degree of the curve is probably 8° 30'. 
 
 3. Calculate by rule 1 the difference in lengths between 
 the inner and the outer rails of a 7° curve 475 feet in 
 length. Ans. 34.29 in. =2. 857 ft. 
 
 4. Solve Example 3 by rule 2. Ans. 2.827 ft. 
 
 1666. Springing Rails into Curve. — Rails should 
 never be sprung and spiked to a curve; the elastic force of 
 the steel is constantly acting, and is sure to force the track 
 out of line. Each passing train, through its centrifugal 
 force, aids the rails to regain their original form. The re- 
 sult is that in a short time the curve, especially it a sharp 
 one, will show an angle at each joint. The effect at these 
 angles is to cause a sudden lurch of the car at each joint, 
 causing not only discomfort to passengers, but serious and 
 constant wear and strain upon the roiling stock. 
 
 1667. Widening Gauge of Curves. — In passing 
 over curved track, the car wheels bind hard against the out- 
 side rail at the curve. The reason for this is that the differ- 
 ence between the gauge of the track and the gauge of the 
 wheels is taken up by the wheel base, which forms a chord 
 to the curve of the track, instead of being parallel to the 
 rails, as is the case on a straight line. To lessen this friction, 
 
1092 TRACK WORK. 
 
 the gauge is usually widened on curves to the amount 
 of y^^ inch per degree, but never to exceed 1 inch on 
 any curve. The increase in gauge is usually made in 
 quarter-inches, that being the amount allowed for 4 degrees. 
 The necessity for widening the gauge on sharp curves is 
 still more apparent when we consider that provision must 
 be made to accommodate cars of both standard gauge (4 
 feet 8^ inches) and for those of 4 feet 9 inches gauge, com- 
 mon to Southern roads. 
 
 When the gauge is not widened, a wide-gauged car is 
 liable to mount the rail, especially if the flanges of the 
 wheels are badly worn and sharp. The effect of all curva- 
 ture is to increase the train resistance, and on sharp curves, 
 this resistance, due to friction, becomes so great as to 
 largely reduce the train load. All train loads are limited 
 by the maximum resistance which they must overcome. 
 This maximum resistance may be concentrated upon a 
 single curve, and it is at once apparent that a railroad com- 
 pany might well incur heavy expense in reducing this curv- 
 ature, if by so doing they could add one extra car to each 
 train load. Another charge against curvature is the loss of 
 time to passenger trains which can not run over sharp 
 curves, except at reduced speed. All curves exceeding eight 
 degrees, besides their resistance to trains, cause a direct 
 loss of time to all fast passenger trains. 
 
 1668. Guard Rails on Short Curves. — On straight 
 track, laid to exact gauge, the guard rail is spaced 1|^ inches 
 from the gauge rail; but when the gauge is widened, as on 
 sharp curves, the amount of the increase in gauge must 
 be added to the space between the gauge and the guard 
 rail, 
 
 1 669. LiniuK Curves. — A common habit of trackmen 
 when lining curves is to throw the curve outwards to line. 
 The effect of this, in time, is to reduce the degree of curva- 
 ture at the ends of the curve and sharpen it at the cen- 
 ter, besides crowding the roadway on the outside of the 
 curve. 
 
TRACK WORK. 1093 
 
 A safe rule is to always throw the track inzvards^ i. e. , tow- 
 ards the center of the curve. It is at once apparent that 
 the effect of the cen- 
 trifugal force of the 
 train in passing over 
 a curve is to throw 
 the track outwards, 
 and in lining curves, 
 the track should be 
 thrown inwards, if 
 for no other purpose 
 than to (Overcome this 
 effect of the trains. 
 The effect of throw- 
 ing the track out- 
 wards when lining a 
 curve is shown in 
 Fig. 518, in which fig.sis. 
 
 ABC represents the true line of the curve and A E C the 
 position of the tracks due to improper lining. 
 
 When track is first laid, there should be a track center 
 stake driven at every 50 feet and carefully centered with a 
 tack. Before and after ballasting, the track should be care- 
 fully lined to the center stakes, and if the rails have been 
 properly curved the track will hold its line, with occasional 
 retouching, for years. 
 
 In the case of a badly lined curve, select a piece of track 
 60 feet in length, which appears to be in good line. There 
 are few curves, however badly out of line, but will show at 
 least 60 feet of good line. At each end of the 60 feet of 
 good track set an accurate center stake, and one in the cen- 
 ter of the track midway between them. In Fig. 519, A 
 and B represent the center stakes 60 feet apart, and C 
 the stake midway between them. Stretch a cord from A 
 to B, and measure the distance from Z, its middle point, 
 to C. The distance C L\s the middle ordinate of a 60-foot 
 chord. Next, mark the middle point L of the chord, and 
 move the end A of the chord to C. Measure from B the 
 
1094 TRACK WORK. 
 
 distance B M— C L, and carry the measuring cord forwards, 
 stretching it taut, and in the line C M, as determined by the 
 offset B M. The forward end D of the cord will mark the 
 spot for another track center. Then, move ahead as before, 
 measuring another offset and stretching the cord to locate 
 another center stake at E. In this way a perfect curve may 
 be run in without the use of an instrument. It is better 
 policy to set the track centers in line with the faces of the 
 stakes for line rather than the tack centers, as the cord is 
 sure to line properly to the faces of the stakes, but in order 
 
 E 
 
 Pig. 519. 
 
 to line their centers they must be practically of the same 
 height, which is sometimes difficult to obtain, especially if 
 the ballast contains stone. 
 
 Having set all the track centers, select a track gauge 
 which is square and true, and mark a point midway between 
 the gauge lines. Then, place the gauge on the track close 
 to the track center, and direct the men to move the track 
 until the middle point of the track gauge coincides with the 
 track center. Line up the track at each track center until 
 the entire curve has been moved to line; then, repeat the 
 operation, giving the final touches, as a second lining should 
 be sufficient. 
 
 1 670. Elevation of Curves. — To counteract the cen- 
 trifugal force which is developed when a car passes around 
 a curve, the outer rail is elevated. The amount of elevation 
 will depend upon the radius of the curve and the speed at 
 
TRACK WORK. 1095 
 
 which trains are to be run. There is, however, a limit 
 in track elevation, as there is a limit in widening gauge, 
 beyond which it is not safe to pass. 
 
 When we consider that the centrifugal force of a car in- 
 creases as the degree of curvature, and as the square of the 
 speedy we readily see how a slight decrease in speed will 
 equalize a great increase in curvature. 
 
 To illustrate: A car passing around an 8-degree curve 
 will have double the centrifugal force of a car passing around 
 a 4 degree curve at the same speed. But to neutralize the 
 eflfect of sharpening the curve from 4 to 8 degrees, it is not 
 necessary to halve the speed, but only to reduce it in an inverse 
 proportion to the square root of the degrees of curvature. 
 Thus, if a speed of 60 miles per hour is admissible on a 4-de- 
 gree curve, the speed on an 8-degree curve is obtained by the 
 proportion 60 : a' = |/8^ : 4/4, or .r = 42.43 miles per hour. 
 If we again double the degree of the curve to 16 degrees, 
 we only reduce the admissible speed of equal safety to 30 
 miles per hour. Hence, it will be seen that the centrifugal 
 force developed by an increase in speed is not proportional 
 to the centrifugal force developed by an increase in curva- 
 ture. In consequence of this varying relation between curva- 
 ture and speed, no fixed rule can be followed for elevating 
 the outer rail of curves. 
 
 It is a safe rule to elevate all curves to suit the highest 
 speed of trains passing over that part of the track. Ordi- 
 narily freight trains require the same track elevation as pas- 
 senger trains. All railroad men know that freight trains 
 repeatedly run at passenger train speed. The aim of every 
 freight train conductor is to "make time, " and he makes 
 it whenever the grades and train loads permit. 
 
 On rolling grades it is often necessary to run down a grade 
 at top speed in order to acquire sufficient momentum to 
 carry the train to the summit of the following grade. Every 
 day fast running is necessary in order to make up for time 
 lost through unavoidable delays; hence, if a curved track is 
 elevated to meet the requirements of passenger trains, freight 
 trains will be equally well served. All curves, when possible, 
 
1096 TRACK WORK. 
 
 should have an elevated approach on the straight main 
 track, of such length that trains may pass on and off the 
 curve without any sudden or disagreeable lurch. The 
 length of the approach should be in proportion to the 
 elevation of the curve and not to its degree. 
 
 A good rule for curve approaches is the following: For 
 each half-inch or fraction thereof of curve elevation, add 
 30 feet or 1 rail length to the approach ; that is, if a curve 
 has an elevation of 2 inches, the approach will have as many 
 rail lengths as ^ is contained in 2, which is 4 times. The 
 approach will, therefore, have a length of 4 rails of 30 feet 
 each, or 120 feet. 
 
 The following formula by Searles, viz. , 
 
 c = 1.5S7V, (113.) 
 
 gives the length of the chord c, whose middle ordinate is 
 equal to the proper elevation of the outer rail of the curve 
 for any velocity V in miles per hour. 
 
 Example. — The curve is 8°, and the velocity 40 miles pei hour ; what 
 is the proper elevation for the outer rail of the curve ? 
 
 Solution. — Substituting the given values in formula 113, 
 ^ = 1.587 V, 
 we have c — 1.587 X 40 = 63.48 feet, the length of the required chord. 
 To find the middle ordinate of this chord, we apply formula 112. 
 We have just found c — 63.48 feet, and R — the radius of an 8° 
 curve = 716.78 feet. 
 
 Substituting these values of c and R in the above formula, we have 
 63.48* 4,029.7 
 
 ^ = 83<-7T6:78 = 57734:2 = -'^^'-"^^'"^y = ^^'"- ^"^- 
 
 This result is too great. The best authorities on this 
 subject place the maximum elevation at \ the gauge, or 
 about 8 inches for standard gauge of 4 feet 8^ inches. The 
 gauge on a 10° curve elevated for a speed of 40 miles an 
 hour should be widened to 4 feet ^d\ inches. 
 
 The following table for elevation of curves is a com- 
 promise between the extremes recommended by different 
 engineers. It is a striking fact that experienced trackmen 
 never elevate track above 6 inches, and many of them 
 place the limit at 5 inches: 
 
TRACK WORK. 
 TABLE 34. 
 
 1097 
 
 Degree 
 of Curve. 
 
 Length of 
 Approach. 
 
 Elevation. 
 
 Width of 
 Gauge. 
 
 Speed 
 
 of Trains. 
 
 1 
 
 60 ft. 
 
 1 in. 
 
 4 ft. 8| in. 
 
 60 m] 
 
 . per hr. 
 
 2 
 
 120 ft. 
 
 2 in. 
 
 4 ft. 8^ in. 
 
 60 mi 
 
 . per hr. 
 
 3 
 
 150 ft. 
 
 2^ in. 
 
 4 ft. 8f in. 
 
 60 mi 
 
 . per hr. 
 
 4 
 
 180 ft. 
 
 2f in. 
 
 4 ft. Si in. 
 
 55 mi 
 
 . per hr. 
 
 5 
 
 180 ft. 
 
 3 in. 
 
 4 ft. 8| in. 
 
 50 mi 
 
 . per hr. 
 
 6 
 
 210 ft. 
 
 Biin. 
 
 4 ft. 8| in. 
 
 45 mi 
 
 . per hr. 
 
 7 
 
 210 ft. 
 
 3iin. 
 
 4 ft. 9 in. 
 
 40 mi 
 
 . per hr. 
 
 8 
 
 240 ft. 
 
 3iin. 
 
 4 ft. 9 in. 
 
 35 mi 
 
 . per hr. 
 
 9 
 
 240 ft. 
 
 4 in. 
 
 4 ft. 9 in. 
 
 30 m 
 
 . per hr. 
 
 10 
 
 270 ft. 
 
 4iin. 
 
 4 ft. 9 in. 
 
 25 m 
 
 . per hr. 
 
 11 
 
 270 ft. 
 
 4iin. 
 
 4 ft. 9i in. 
 
 20 m 
 
 . per hr. 
 
 12 
 
 270 ft. 
 
 4f in. 
 
 4 ft. 9i in. 
 
 15 m 
 
 . per hr. 
 
 13 
 
 240 ft. 
 
 4i in. 
 
 4 ft. 9i in. 
 
 10 m 
 
 . per hr. 
 
 14 
 
 240 ft. 
 
 4iin. 
 
 4- ft. 9iin. 
 
 10 m 
 
 1. per hr. 
 
 15 
 
 240 ft. 
 
 4 in. 
 
 4 ft. 9^ in. 
 
 10 m 
 
 I. per hr. 
 
 16 
 
 240 ft. 
 
 4 in. 
 
 4 ft. 9^ in. 
 
 10 m 
 
 . per hr. 
 
 Many persons overrate the objections to sharp curves, 
 especially where the grades are low. Their great objection 
 is not in their being an obstacle to high speed, but in their 
 great resistance to traction. Freight trains, which are 
 usually heavily loaded, are much more impeded by sharp 
 curves than passenger trains, which are generally lighter 
 and made up of cars which more readily adjust themselves 
 to irregularities in line and surface. 
 
 No curve exceeding 10 degrees should be placed in the 
 main line of any railroad. The additional cost of operating 
 and maintaining a sharper curve would pay for tne addi- 
 tional outlay necessary to bring the degree within the 10- 
 degree standard. Many roads place the maximum curve at 
 6 degrees, and though beyond the reach of many roads, it is 
 a safe standard. 
 
1098 TRACK WORK. 
 
 Besides the loss of time necessitated by running slowly on 
 short curves, there is a much greater loss due to the wear 
 and tear on rolling stock and upon the rails themselves. 
 The friction of the wheel flanges against the rails rapidly 
 wears them out, and the continual lurching and rolling of 
 the cars detract greatly from the comfort of passengers. 
 
 Most of the trunk lines in the United States have been 
 greatly improved since their first construction, especially in 
 their alinement, some of them being practically rebuilt. 
 The Pennsylvania R. R. between Philadelphia and Harris- 
 burg is a striking instance of the great improvement, both 
 in alinement and grade, of a line originally cheaply and 
 poorly built. Many of the original curves have been re- 
 moved, and all of them lightened. In many places the 
 original line has been entirely abandoned, and a new and 
 better one adopted. This road is, however, an exceptional 
 case, as few lines in the world could afford to make slight 
 changes involving so great cost. 
 
 1671. The Elevation of Turnout Curves. — The 
 
 speed of all trains in passing over turnout curves and cross- 
 overs is greatly reduced, so that an elevation of ^ inch 
 per degree is amply sufficient for all curves under 16 degrees. 
 On curves exceeding 16 degrees, the elevation may be held 
 at 4 inches until 20 degrees is reached, and on curves ex- 
 ceeding 20 degrees, -^ of an inch of elevation per degree 
 may be allowed until the total elevation amounts to 5 inches, 
 which is sufficient for the shortest curves. 
 
 1672. Curve Approaches liet^'een Reverse 
 Curves. — If possible, there should be a level piece of track, 
 at least 60 feet in length, between reverse curves, besides 
 the elevated approaches to the curves. When the whole of 
 the intermediate tangent is required in making the elevated 
 approaches to the curves, commence at the middle of the 
 intermediate tangent, if both curves are of the same degree. 
 If, however, they are of different degrees, make the ap- 
 proach to each curve in proportion to its degree. In ele- 
 vating the approaches to the curves, give to the first rail 
 
TRACK WORK. 
 
 1099 
 
 length an elevation of ^ inch, after which give ^ inch addi- 
 tional elevation per rail length, or, if necessary, 1 inch 
 additional elevation, so as to make the total elevation of the 
 approach equal to the elevation of the outer rail of the 
 curve. 
 
 When a curve is compounded, commence to increase or 
 decrease the elevation far enough back from the point of 
 compound curvature to give to the second branch of the 
 compound curve the elevation which it requires. This in- 
 crease or decrease in elevation is made at the rate of ^ inch 
 per rail length, precisely as in elevating the approach to a 
 regular curve. When the changes in a compound curve are 
 frequent and abrupt, it is best to elevate the outer rail for 
 the highest degree of the curve and carry this elevation 
 uniformly throughout the curve. 
 
 1673. Putting the Elevation in Curves. — If the 
 
 track is in good surface, first catch up all the low joints on 
 the inner rail of the curve. The elevation of the outer rail 
 is determined by means of the track level shown in Fig. 
 520. For leveling track, the edge a boi the track level is 
 
 Fig. 520. 
 
 placed upon the rails, and when perfectly level the bubble c 
 of the spirit level will rest in the middle of the tube. The 
 steps d, e, etc., of the track level are made 1 inch in height, 
 so that when the step ^-is placed on the outer rail of a curve 
 and the rail raised until the bubble of the spirit level rests 
 in the middle of the tube, the outer rail has an elevation of 
 1 inch. Similarly, the step e, when brought to a level, 
 would indicate a track elevation of 2 inches, etc. 
 
 Having determined the amount of elevation required for 
 the curve, the outer rail is raised with the track jack and the 
 ballast thoroughly tamped under the ties. The elevation 
 
1100 TRACK WORK. 
 
 should be about ^ inch in excess of that required, in order 
 that provision may be made for settlement. 
 
 In dressing the track after the elevation has been made, 
 make the crown of the ballast at not more than one-third 
 of the width of the gauge from the outer rail, in order to 
 secure drainage. The raising of the outer rail reduces the 
 outer slope and increases the inner slope of the ballast. If 
 the curve is sharp, the ballast on the outer half of the track 
 is practically level and holds water, instead of shedding it. 
 By crowning the ballast as directed, thorough drainage is in- 
 sured. 
 
 1674. The Effects of Curved Track upon Loco- 
 motive and Car Wheels. — The effect of all curved track, 
 however easy the curve, is to wear the flanges and treads of 
 car wheels. This effect is due to the centrifugal force which 
 forces the flanges of the wheels against the head of the out- 
 side rail of the curve. 
 
 The elevation of the outer rail, the widening of the gauge, 
 and the coning of the car wheels, all combine to reduce this 
 friction and consequent wear. 
 
 Where the elevation is insufficient, the friction increases, 
 and if the gauge is the same as on straight track, there is 
 great danger of the wheels mounting the rails, especially if 
 the flanges are badly worn. The conclusion from many 
 years of experiment and close observation is that the wear 
 of rails on curved track is largely due to the driving wheels 
 of the engine. When the tires become worn, the wear of 
 the rails rapidly increases, and hence the importance of 
 careful and repeated inspection of the driving wheels. As 
 soon as they show considerable wear, the tires should be 
 turned off to true lines. Besides preventing unnecessary 
 wear of rails, this greatly increases the tractive power of 
 the engine. When the treads of car wheels become badly 
 worn, especially at the flanges, there is bound to be more or 
 less slipping of the wheels. For the outer rail, being the 
 circumference of a greater circle, should require a wheel of 
 greater diameter than the inner wheel, if both are to make 
 
TRACK WORK. 
 
 1101 
 
 the same number of revolutions. This increased diameter is 
 given by the coning of the wheels, shown in Fig. 521, in 
 which the rail a is on the outside of the curve. An inspec- 
 tion of the figure will show that the cone-shaped tread of the 
 wheel b gives a greater diameter to the wheel at c d than at 
 e f. In passing around the curve, the flange of the wheel b 
 is forced against the rail a, while the flange of the wheel Ji 
 recedes from the rail g. This increases the diameter of the 
 wheel b, while decreasing that of the wheel //, and so the ex- 
 
 Fig. 521. 
 
 cess in length of the outer rail of the curve is at least par- 
 tially covered. 
 
 Careful experiment proves that under the most favoring 
 conditions some slipping of the wheels is bound to occur. 
 The friction between wheels and rails rapidly increases as the 
 rails become worn, and, as soon as the head of the outer rail 
 of a curve becomes badly worn, the outer rail should be 
 taken up and placed on the inside of the curve, and the 
 inner rail put in its place. This furnishes almost new wear- 
 ing surfaces to the wheel, and the life of the rails is greatly 
 prolonged. 
 
 1675. Care of Curved Track. — As curved track 
 offers greater resistance and greater danger to passing 
 trains than straight track, special eff"ort and pains should be 
 taken to maintain it in perfect order. All trackmen know 
 that a low spot on a curve will cause every car in a train to 
 
1102 
 
 TRACK WORK. 
 
 lurch heavily towards the low side. By careful watching, 
 and by prompt and thorough repairs, 
 curved track may be kept in perfect or- 
 der. It is highly important that the ele- 
 vation of the outer rail be kept uniform, 
 and no foreman, however experienced, 
 should place dependence upon his eye in 
 estimating curve elevation. 
 
 Both the civil engineer and the track 
 forepian will do well to cultivate each 
 other, the engineer imparting theoretical 
 knowledge in exchange for practical 
 knowledge. The result will certainly pro- 
 mote mutual respect and enhance the 
 efficiency of both. 
 
 FROGS AND SWITCHES. 
 
 FROGS. 
 1676. Turnouts. — A turnout is a 
 device for enabling an engine and train to 
 pass from one track to another. It con- 
 sists of two lines of rails a b and c d (see 
 Fig. 522), so laid as to form a reversed 
 curve uniting the two tracks A B and 
 C D. The several parts of a turnout are 
 as follows: The switch rails r / and 
 gh^ the frogX', and the two guard-rails 
 / m and n o. The stationary ends c and 
 g of the switch rails are called the heels, 
 and the movable ends / and h are called 
 the toes. The distance / /», through 
 which the toes /"and // move, is called the 
 throw. The throw must equal the width 
 of the head of the rail, with sufficient 
 additional width to allow the flanges of the 
 wheels to pass freely between the main rails r s and / ti and 
 
TRACK WORK. 1103 
 
 the turnout rails a b and c d. The throw on tracks of stand- 
 ard gauge is 5 inches; that is, the toes /"and // are moved 5 
 inches from their original position in the main track in 
 forming the turnout curve on which the train is to pass 
 from the main track ^ ^ to the siding C D. 
 
 The movement of the switch rails is effected by means of 
 a lever. 
 
 1677. The Frog. — The frog is a device by means of 
 which the rail at the turnout curve crosses the rail of the 
 main track. The frog shown in Fig. 523 is made of rails 
 having the same cross-section as those used in the track. 
 Its parts are as follows: The wedge shaped part A is the 
 tongue, of which the extreme end a is the point. The 
 space b, between the ends c and ^^of the rails, is the mouth, 
 
 Fig. 533. 
 
 and the channel which they form at its narrowest point e is 
 the throat. The curved ends/ and g are the wings. 
 
 That part of the frog between A and A' is called the 
 heel. The width h of the frog is called its spread. Holes 
 are drilled in the ends of the rails c^ d, k, and / to receive the 
 bolts used in fastening the rail splices, so that the rails of 
 which the frog is composed form a part of the continuous 
 track. 
 
 1678. The Frog Point.— The theoretical point of 
 frog a' (see Fig. 523) and the actual point a are quite dis- 
 similar. The reason for making a the point of frog is that 
 if the theoretical and actual point of frog were the same, 
 the point would be so small that the first blow inflicted by 
 a passing locomotive or car would completely destroy it. 
 The frog point is accordingly placed at rt, where its width 
 is about \ of an inch. 
 
1104 
 
 TRACK WORK. 
 
 1(>79. The Frog Number. — The number of a frog is 
 the ratio of its length to its breadth, i. e., the quotient of 
 its length divided by its breadth. 
 
 Thus, in Fig. 523, if the length a' /, from point to heel of 
 frog is 5 feet, or 60 inches, and the breadth h of the heel is 
 15 inches, the number of the frog is the quotient of GO -r- 15 = 
 4. Theoretically, the length of the frog is the distance 
 from a to the middle point of a line drawn from k to /; 
 practically, we take as the length the distance from a to /. 
 As it is often difficult to determine the exact point a of the 
 frog, a more accurate method of determining the frog num- 
 ber is to measure the entire length d I of the frog from mouth 
 to heel, and divide this lefigth by the sum of the mouth width 
 b and the heel width h. The quotient will be the exact number 
 of the frog. 
 
 For example, if in Fig. 523, the total length d I oi the 
 frog is 7 feet 4 inches, or 88 inches, and the width /; is 15 
 inches, and the width b of the mouth is 7 inches, then the 
 frog number is 88 -=- (15 -f 7) = 4. Frogs are known by 
 their numbers. That in Fig. 523 is a No. 4 frog. 
 
 1680. The Frog Angle. — The frog angle is the 
 
 angle formed by the gauge lines of the rails, which form its 
 tongue. Thus, in Fig. 523, the frog angle is the angle la' k. 
 The amount of the angle may be found as follows: The 
 tongue and heel of the frog form an isosceles triangle (see 
 Fig. 524). By drawing a line from the point a of the frog 
 
 to the middle point b of the heel c d, we form a right-angled 
 triangle, right-angled at b. The perpendicular line a b. 
 
TRACK WORK. 
 
 1105 
 
 bisects the angle a, and, by rule 5, Art. 754, we have tan 
 
 be 
 ^ a =: —J. The dimensions of the frog point given in Fig. 
 
 52-4 are not the same as those given in Fig. 523, but their 
 relative proportions are the same, viz., the length is four 
 times the breadth. The length a ^ .— 4, and the w^idth 
 c d = 1; hence, d c — ^. Substituting these values, we have 
 
 tan ^ rtr = f = ^ = 0. 125. Whence, ^ a = 7° 7^', and a = 
 
 14° 15'; that is, the angle of a No. 4 frog is 14° 15'. 
 
 Frog numbers run from 4 to 12, including half numbers, 
 the spread of the frog increasing as the number decreases. 
 
 1 681 . Classification and Description of Frogs. — 
 
 Frogs, as manufactured to-day, are of two classes, viz., sti^ 
 frogs and sprtng-rail frogs. Each has advantages peculiar 
 to itself, which specially adapt it to certain situations. 
 Stiff frogs contain much less material and require less 
 shop work than spring frogs. For a given angle a stiff 
 frog requires less space, and hence is better adapted to yard 
 work than spring-rail frogs. They are more simply con- 
 structed than spring frogs, and can be made at any well- 
 equipped machine shop. 
 
 Spring-rail frogs, because of their furnishing an unbroken 
 surface to the wheel treads, are particularly adapted to the 
 heavy traffic of a trunk line. 
 
 Pig. 625. 
 
 Figs. 525 and 526 represent the best types of stiff frogs. 
 The frog shown in Fig. 525 is called a plate frog. The 
 rails composing the frog are fastened to a plate of wrought 
 iron or steel a c d b by means of rivets through the rail 
 flanges, as shown in the figure. Square holes r, f are 
 
1106 TRACK WORK. 
 
 punched in the plate to receive the railroad spikes, which 
 are driven into the cross-ties supporting the frog, holding it 
 firmly in place. Plate frogs are perfectly rigid, and by many 
 railroad men are considered inferior to the keyed frog, 
 shown in Fig. 526, which is somewhat flexible and better 
 
 (fix iff r£fe\ 
 
 ^ B 
 
 Fig. 526. 
 
 suited to yard work where the curves are sharp and the frog 
 angles correspondingly large. 
 
 In this frog, the pieces of rails a and I?, forming the point, 
 are dovetailed together and secured by heavy rivets. To 
 retain the full strength and durability of the steel, all the 
 parts are fitted without being heated, excepting the wings, 
 which are bent at a very low heat. Hence, the strength of 
 the rails is in no respect diminished, and the method of 
 securing the parts together has advantages over bolts or 
 rivets passing through the webs or flanges of the rails, as 
 there is nothing which can come in contact with the wheel 
 flanges. From its peculiar construction, it has the same 
 elasticity as the rails in the track, which makes it an easy 
 riding frog, more durable than a rigid frog, and less liable 
 to injury from uneven ballasting. It presents little obstruc- 
 tion to tamping, and, when fastened into the track with the 
 usual angle splices, it is firm, stable, and free from any 
 tendency to jump or move. 
 
 The parts are bound together by heavy wrought-iron 
 clamps c and d^ shown in the cross-sections A and />, A 
 being a cross-section through the first clamp and B one 
 
TRACK WORK. 1107 
 
 through the second clamp. These clamps are tightened by 
 means of beveled split keys, or wedges, e and/", the ends of 
 the clamps being bent over a form to an exact angle, at one 
 end to fit the brace blocks k and k' on the outside of the 
 rail, and at the other end to fit the beveled keys, which are 
 driven into the spaces between the end of the clamp and the 
 smaller brace blocks /, /'. The keys lie on the flange of the 
 rail, which prevents them from dropping down in case they 
 loosen. The flange way between the frog point and the wing 
 rails is maintained by iron throat-pieces g, h, g\ and h\ 
 which fit the rails perfectly, and, extending beyond the 
 point, thoroughly brace and stay it against lateral stresses. 
 After tlie keys are driven to the extent necessary to bind 
 the parts solidly together, the split ends are spread to 
 prevent the keys from working out. 
 
 The throat-pieces, as well as the brace blocks, are effect- 
 ually prevented from sliding out of their positions. The 
 clamps are firmly secured to the flanges of the rails, and the 
 only movable pieces in the frog are the keys which, being 
 thicker on their lower edge (owing to being beveled un- 
 equally), together with the angles of the clamps, prevent 
 the keys from working upwards. Trackmen, when inspect- 
 ing track, should always examine the frogs, and any key 
 loosened by the wearing of the parts should be tightly driven, 
 and the split end spread open. Unless a key is loose it 
 should never be hammered. 
 
 A standard type of a spring-rail frog of keyed pattern 
 is shown in Fig. 527. For main line tracks, and especially 
 for those sections where the heavy traffic moves principally 
 in one direction, the spring-rail frog is recommended. It 
 gives to the main line the smoothness of an unbroken track; 
 it is simple in its construction, thoroughly substantial, and is 
 placed in position with the least amount of labor. 
 
 As shown in the figure, the fixed parts of the patent keyed 
 spring frog 2st. bound together by two heavy clamps rt and b^ 
 shown in the details A and B, which are sections through 
 the clamps zX. C D and E F. The parts within the clamps 
 are secured by split keys or wedges c and d. The frog point 
 
1108 
 
 TRACK WORK. 
 
 G is made of two 
 pieces of steel rail 
 fitted and dovetailed 
 together by machin- 
 ery, without being 
 heated, and securely 
 riveted together. The 
 flange way between 
 the point and wing 
 rails is maintained by 
 closely fitting iron 
 throat-pieces e and f 
 (shown in the detail 
 sections A and B^, 
 which are prevented 
 from slipping by rivets 
 and pins through the 
 rails. The clamps 
 have side notches g 
 and g' at one end 
 (shown in detail at Z), 
 which engage with 
 notches in the flange 
 at the frog point, and 
 prevent the clamps 
 from slipping down, 
 even if loose. The 
 other end of the clamp 
 is bent over a form to 
 an exact angle to fit 
 the beveled split key, 
 which is driven into 
 the space between the 
 clamp and the block, 
 which is fitted and se- 
 cured to the side wing 
 rail. When the key is 
 driven, the parts of 
 
/ 
 
V* "j ^ ii , Lil |ii| 
 
 
.\.\. 
 
 i— -- 
 
 /' 
 
TRACK WORK. 1109 
 
 the frog are tightly bound together, and the key resting 
 upon the flange of the rail is prevented from working down 
 and loosening. The outer end of the clamp is secured by 
 clips, which are riveted to the flange of the rail. 
 
 In case the parts of the frog become loosened by wear, 
 they may be tightened by driving the wedge further in and 
 spreading the split ends so as to hold the key firmly in place. 
 
 That part of the flange of the spring rail next to the frog 
 point is planed off, allowing the head of the spring rail to 
 lie close to the frog point, forming almost a continuous rail 
 and fully accommodating all classes of wheels passing the 
 frog. Powerful springs H and K hold the spring rail firmly 
 against the frog point, and the slide arm //, which is held in 
 place by the clip k, attached to the slide plate (shown in the 
 detail section M N), prevents the spring rail from rising up 
 or moving out too far. The usual length of this spring frog 
 for any angle is 15 feet. 
 
 1682. Crossing Frogs. — Where one railroad crosses 
 another at grade, frogs of special design, called crossing 
 frogs, are required. They are of various patterns, depend- 
 ing upon the angle of the crossing and the importance of 
 the line. In Fig. 528 a cut is given of a standard crossings 
 which embodies the best features as determined by ex- 
 perience. 
 
 This crossing is made of the best quality steel rails, fitted 
 with exactness. The points are mitered, dovetailed, welded, 
 or forged out of solid rails, the angle of the crossing and the 
 requirements of the case determining which method is the 
 most practicable. The rails are mounted on strong wrought- 
 iron bed-plates A, B, etc., to which they are securely riveted 
 through the flanges of the rails. The guard-rails a, b, c, and 
 d, inside the intersecting tracks, extend unbroken on all 
 sides, and extend outside the frog points so as to guide the 
 trucks, causing them to pass squarely through the crossing. 
 
 At all the angles the flange way is completely filled by 
 wrought-iron throat fillers c, /, and c, which are shaped to 
 exactly fit the rails. 
 
1110 
 
 TRACK WORK. 
 
 All the corners are braced with heavy wrought-iron 
 braces^, h, k^ etc., forged to shape and planed to fit solid 
 in the fishing spaces of the rails. Strong bolts, /, m, etc., 
 passing through the webs of the rails, the throat fillers, 
 and corner braces, bind the parts of the crossing firmly to- 
 gether. 
 
 All the inside splice joints are provided with solid iron 
 throat blocks «, o between the rails in addition to the usual 
 splice bars. The splice bolts / and q pass through splice 
 bar, throat block, and rail, binding all securely together. 
 Care should be taken that no bolts project through the bed- 
 plates, necessitating the cutting of pockets in the crossing 
 timbers to receive the bolt heads, as increased decay is sure" 
 to follow. 
 
 1683. Replacing Frogs. — A replacing frog is a 
 
 device for replacing derailed cars upon the track. Such a 
 frog must combine portability and great strength. It must 
 be flexible and compact, and of simple construction. 
 
 The replacing frog shown in Fig. 529 combines practically 
 all of these qualities. This frog consists of a heavy steel 
 
 Fig. 529. 
 
 bar a slightly curved. The bar is bolted at one end to a 
 heavy steel hook b which hooks under the head of the rail. 
 The joint r, connecting the bar and hook, allows the frog to 
 be placed in any desired position. The end d oi the bar is 
 hooked and pointed. In using the frog, the hook b is first 
 adjusted; the end d is then placed directly in front of the 
 wheel of the derailed truck, and the point d of the bar 
 driven into the cross-tie with a sledge. This holds the 
 
TRACK WORK. 1111 
 
 replacing frog rigidly in place. A replacing frog is placed in 
 position on both rails, and the car pulled on to the track 
 with a locomotive. Where the trucks are slewed crosswise 
 to the track, the car must be jacked up and the trucks 
 straightened before placing the frogs. 
 
 SWITCHES. 
 
 1 684. Classification of Switches. — Although there 
 have been many different kinds of switches devised, only two 
 of them have ever been in general use; viz., stub and split, 
 or point, switches. Stub switches are now rarely used on 
 first-class roads, even in yards, the split or point switch hav- 
 ing entirely supplanted them. It is estimated that 50 per 
 cent, of the derailments on American lines have been direct- 
 ly chargeable to the defects of the stub switch. 
 
 The principal defect in the stub switch lies in the open 
 joint at the head-block. In passing over this joint, each 
 wheel delivers a heavy blow on the ends of the rails at the 
 point, which not only batters the rails but also causes a 
 heavy jolt to the car, injurious to the rolling stock and caus- 
 ing much discomfort to passengers. Stub switches are 
 more liable to misplacement than split switches, and there is 
 the constantly recurring need of recutting the ends of the 
 rails at the head-block, to provide for expansion and for the 
 removal of battered ends. 
 
 1685. The Stub Switch.— The essential parts of a 
 stub switch are shown at A in Fig. 530. The rails a b and 
 c d are the switch rails placed for the turnout track. 
 Their position when placed for the main track is indicated 
 by dotted lines at e and/". The switch rails are commonly 
 used in lengths of 30 feet, the standard rail length, of which 
 only 22 feet are free to move or slide, the remaining 8 feet 
 being spiked to the ties, as shown in the figure. The mov- 
 ing portions of the switch rails are held in place by rods g^ h, 
 k, and /, called s^vitch rods. These rods keep the switch 
 rails at proper gauge, and serve the purpose of track spikes. 
 
1112 
 
 TRACK WORK. 
 
 
 
 
 ^fe^M 
 
 
 1 
 
 
 F 
 
 ' 
 
 ^ 
 
TRACK WORK. 1113 
 
 The first switch rod g is called the head rod. It extends 
 outside the rails, and by means of the connection rod in, 
 
 it is attached to the lever n of the switch stand, by means 
 of which the switch rails are moved from their connection 
 with the main track rails o and />, to a connection with the 
 turnout rails ^ and r. This movement of the switch rails is 
 termed throwing the switch. 
 
 The switch stand, and connection and head rods of this 
 switch are shown in detail at B. The switch stand Z> con- 
 sists of a cast-iron plate s to which is cast a semicircular 
 lug /. A hole in this lug receives a pin, which is attached 
 to the end of the lever n. The connection rod ;// is attached 
 to the lever by means of the pin u, and is held in place by a 
 nut. The lever handle is slotted, and when the switch is 
 set for either track, the slot fits over a staple v, projecting 
 above the lever far enough to receive a padlock w which 
 locks the switch. 
 
 The switch rods clamp the switch rails firmly, as shown at 
 X. The head chair, shown at E, is of cast iron, and con- 
 tains sockets^, y, into which the ends of the main and turn- 
 out rails o and q securely fit. The lateral movement of the 
 switch rail is limited by the lugs z and z\ which are cast into 
 the chair. The head chair is usually fastened to the head- 
 block with track spikes. 
 
 The cross-tie F, which supports the head chairs and switch 
 stand, is called the head block. The head block and all 
 other switch ties should be of hard wood — oak preferably. 
 The ties under the switch rails should be of sawed timber, 
 so as to present a smooth even surface for the sliding 
 rails. 
 
 This type of switch stand is equally well suited to split 
 switches, and on account of its compactness is especially 
 suited to yard work. 
 
 The stub switch is cheaper than the split switch, and for 
 tracks owned by private concerns, it serves very well ; but 
 for railroads doing a regular freight and passenger business, 
 it is not only out of date, but should be condemned as 
 unsafe. 
 
1114 
 
TRACK WORK. .1115 
 
 1686. Split, or Point, Switches.— The split, or 
 point, switch does away with the open joint at the head 
 block and gives a continuous bearing to the car wheels. The 
 two common types of split switches are shown in Figs. 531 
 and 532. In Fig. 531, the rails A A' and ^^' are called the 
 stock rails. In the split switch, the heels and toes of the 
 switch rails are exactly the reverse of those in the stub 
 switch, i. e. , the heels in the split switch are in the places 
 occupied by the toes in the stub switch. The stock rails are 
 spiked throughout their entire length. The switch rails 
 C C\ D D' are usually 15 feet in length for all turnouts 
 excepting those in yards where limited space requires very 
 sharp curves, and switch points 12 feet in length, or even less, 
 are used instead. 
 
 The switch rails are usually straight and planed down so 
 as to fit closely to the stock rails for 6 or 7 feet. The points 
 C and D are planed down to a thin edge, the web of the 
 switch rail being grooved so as to fit under the head of the 
 stock rail. 
 
 The base of the switch rail is planed so that it fits snugly 
 against the upper part of the base of the stock rail. The ex- 
 treme points of the switch rails are slightly below the level 
 of the stock rails, so that the wheel treads do not come in 
 contact with them until their size and strength are sufficient 
 to stand the hard pounding which all switches receive. 
 
 The slide plates a, b, c^ d^ e^ and /"extend under the stock 
 rails and points, and are spiked to the cross-ties. The 
 switch rods g, h, k, /, and m are of wrought iron, and of such 
 dimensions as the size and weight of the rail require. They 
 are fastened to the switch rails in various ways. In Fig. 531, 
 the connection is made by means of cast steel sockets which 
 are belted to the webs of the rails. The switch rod g, con- 
 necting directly with the switch stand, is called theliead rod, 
 and is shown in detail at E. The cast-steel sockets // and n' 
 are longer, and extend low enough to permit the head rod to 
 pass under the rails, as shown in the detail. The head rod 
 is fastened to each socket with two bolts, while the other 
 switch rods are single bolted. 
 
1116 . TRACK WORK. 
 
 The stock rails are spiked only on the outsides of the rails, 
 and to prevent the rails from getting out of line, the slide 
 plates are bent upwards at the outside of the rail, forming 
 the lip o (see detail at 7^), which holds the rail brace p solidly 
 against the stock rail. 
 
 The connection rod q is fastened at one end to the head 
 rod and at the other end to the crank r of the switch stand, 
 shown in detail at G. The switch stand rests upon two 
 cross-ties s and s\ being securely fastened to them either 
 with bolts or track spikes. The switch stand consists of the 
 column-shaped support /, the lever «, used in throwing the 
 switch, the target ?', and the crank-shaft r. 
 
 The target v consists of two rectangular pieces of sheet 
 iron fastened to the target rod at right angles to each other. 
 One-half of the target is usually painted white, indicating 
 safety, and the other half red, indicating danger. They 
 are so adjusted that an open switch always indicates 
 danger. 
 
 The lever u carries a. cam or eccentric-shaped disk u> which, 
 when in the position u, fits between lugs x\ the lugs are 
 bolted to the pedestal t, and form a part of the rigid stand. 
 When the lever is in the position //, the switch may be locked, 
 holding the switch firmly in place. To throw the switch, 
 raise the lever to the position u'. This releases the cam w 
 from the lug x, and the lever being clamped to the target 
 rod or shaft J, any movement of the lever u is communi- 
 cated to the crank r, which, by means of the connection rod 
 g, acts directly upon the switch rails. 
 
 The throw of the switch is from 4^ to 5 inches. The rail 
 braces / are usually of forged steel, though some are still 
 made of cast iron. 
 
 1687. Safety Switches. — When a train passes from 
 the main track to the side track, it necessarily passes 
 the points of the switch first. Such a switch is called a 
 facing switcti. When, on the other hand, a train passes 
 from the side track to the main track, it passes the frog 
 first. Such a switch is called a trailing switch. 
 
TRACK WORK. 
 
 1117 
 
1118 TRACK WORK. 
 
 William Lorenz, chief engineer of the Philadelphia and 
 Reading Railroad, has the credit of designing a self-acting 
 switch, which is provided with a powerful spring that holds 
 the switch points firmly against the stock rail, thus keeping 
 the main track constantly unbroken. With the switch 
 points in this position, a train can make a trailing switch, 
 the wheel flanges forcing the switch open as they pass from 
 the side to the main track. As the spring is constantly act- 
 ing, each wheel throws the switch, which instantly resumes 
 its position for the main track. 
 
 Such a switch is called a Lorenz, or safety switch, 
 and is shown in Fig. 532. With the exception of the spiral 
 spring'^, which is attached to the head rod and holds the 
 switch point a against the stock rail b, this switch is similar 
 to that shown in Fig. 531. 
 
 The switch rods c, d, and e, instead of being single rods 
 "W^ith arms at their ends for attaching them to the switch 
 rails, as in Fig. 531, have a trussed center piece, shown in 
 detail at B, composed of two bars/" and g, riveted together 
 and leaving between them just space enough to allow the 
 ends of the arms // and k to move as the switch is thrown 
 from one side of the track to the other, the arms pivoting 
 on the rivets / and in at the end of the center piece. 
 
 This form of switch rod combines flexibility with great 
 strength, insuring easy movement to the switch and great 
 resistance to the severe stresses which are continually 
 brought to bear against it. 
 
 The switch rods are bent downwards near the arms, bring- 
 ing them nearly on a level with the top of the tie, where 
 they are less exposed to injury from derailed cars or from 
 broken parts of the cars, such as brake rods or beams, which 
 dragging on the ties frequently catch in switch rods, doing 
 much harm. 
 
 The safety switch, shown in Fig. 532, is of a pattern com- 
 monly used in yards and terminals. The switch points vary 
 in length from 7^ feet to 12 feet, the former fitting all frog 
 numbers as high as 7, and the latter serving for frogs of all 
 numbers. 
 
TRACK WORK. 1119 
 
 The advantages of this switch are its compactness, requi- 
 ring little more than half the space of an ordinary switch; 
 lightness, which insures easy handling, and its adaptation to 
 sharp curves which abound in yards and terminals. The 
 short points permit of trailing switches equally as well as 
 facing switches, as the planed portion of the points is short, 
 and, consequently, carries a much shorter proportion of the 
 wheel base of an engine or car than the switch of the standard 
 length. The short points also require lighter springs than 
 the standard lengths, and are much easier cleared of snow. 
 The details of the switch are practically the same as those of 
 the switch shown in Fig. 531, which were fully described. A 
 common yard stand suitable for this switch is shown in both 
 plan and elevation at C. The target is about 4 feet above the 
 ground, and is provided with an attachment for signal 
 lamp. The lever is hinge-jointed, and in throwing the switch, 
 the lever is brought into a horizontal position, resting on 
 the semicircular iron latch plate E. In the edge of this 
 plate are two slots n and o^ into which the lever hinges after 
 the switch is thrown. Lugs/ and q at the sides of the slots, 
 limit the lateral movement of the lever. The switch stand 
 is secured to the head-block by either bolts or track spikes, 
 usually the latter. 
 
 1688. Three-Throw Switches. — A cut of a three- 
 throw, or double-throw, switch is given in Fig. 533. The 
 type is that of the ordinary stub switch, except that the mov- 
 ing or switch rails serve two turnout tracks instead of but 
 one. The head chair A is usually of cast iron and contains 
 sockets rt, ^, and c (see detail B) for the fixed rails d^ e, and/". 
 
 The switch rails ^ and h have a total lateral movement at 
 the head chairs of from 10 to 12 inches, depending upon the 
 dimensions of the rails. Their lateral movement is fixed by 
 the lugs^, k on the head chairs. 
 
 The switch stand is shown in elevation at C, and in plan 
 at D. The three positions of the switch are fixed by the 
 slots /, w, and o in the latch plate into which the switch lever 
 hinges. 
 
1120 
 
 TRACK WORK. 
 
 A more comprehensive idea of a double-throw switch may 
 be obtained from the detail given at E, which shows to a re- 
 
 FIG. KM. 
 
 duced scale the switch and both turnout curves with main 
 rail frogs/ and v, and the crotcli frog r, by means of which 
 
TRACK WORK. 
 
 1121 
 
 the outer rails of the turnout curves cross each other. The 
 turnout curves of a double-throw switch are usually of the 
 same degree, which brings the crotch frog in the middle of 
 the main track. 
 
 The defects of the stub switch already described should 
 prevent its use.in the main track at yards, and at terminals 
 where trains move slowly, as well as at intermediate points 
 where trains run at top speed. 
 
 A double-throw split switch has been invented and used 
 in a limited way, and though a perfect switch so far as mech- 
 anism is concerned, it is much more expensive and 
 complicated than a double-throw stub switch, and is not 
 enduring. 
 
 The object of the double-throw switch, viz., economy of 
 space, is practically attained by substituting two single split 
 
 Fig. 534. 
 
 switches, placed as close together as is consistent with their 
 safe operation. Such an arrangement is shown in Fig. 534, 
 in which a a' and b b' are the rails of the main track. A 
 7° 30' turnout curve c e \^ laid out to the right of the main 
 track. This calls for a head block at c and a No. 9 frog at/". 
 A 17° turnout curve g in is next laid out to the left of the 
 main track, with its P. C. located so as to bring the head 
 block ^ of the second switch far enough from the heel d of 
 the first switch to afford suflEicient room for operating the 
 second switch. This calls for a No. 6 frog at k and a No. 5^ 
 crotch frog at /. 
 
 1689. Derailing Switches.— A derailing switch 
 
 is a device for derailing cars, and so preventing them from 
 accidentally running out of the siding on the main track. 
 
1122 
 
 TRACK WORK. 
 
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TRACK WORK. 1123 
 
 They are, of course, needed only for sidings built with 
 grades descending towards the switch. 
 
 An effective type of a derailing switch is shown at A in 
 Fig. 535. It consists of a single switch rail a, which is 
 hinged at the rail joint d. The switch point c is beveled, as 
 shown in the detail at C. When the switch is closed, this 
 beveled switch point rests against the outside rail of the 
 siding, which is bent at an angle corresponding to the bevel 
 of the switch point and shown at d, forming a lap switch. 
 When the switch is open, the switch point rests against the 
 guard rail e, the end of which is beveled to form a seat for 
 the switch point. The beveled ends of both track and 
 guard rail rest upon a wrought-iron head chair /, shown in 
 detail at C, upon which the switch point slides. 
 
 This switch is connected with and operated by the move- 
 ment of the main line switch B. The figure shows the 
 switch set for the main line, and the derailing switch set to 
 throw from the track a car moving out of the siding. 
 
 The derailing switch is operated as follows: A bell-crank 
 g is pivoted to a cross-tie, with one end of the crank at- 
 tached to the head rod of the switch B. To the other end 
 of the crank is attached a strong steel wire which extends to 
 a sheave //, directly opposite the derailing switch A, and 
 thence to an eye k, as shown in detail at C and D, in the 
 end of the head rod. This wire is kept taut, so that any 
 movement of the switch B is communicated directly to the 
 switch rail a. The connection rod / is attached to the short 
 arm in of the switch lever; and when the switch is set for 
 the main line E E, as shown in the figure, the resulting 
 stress in the wire is transmitted to the short arm m of the 
 derailing switch lever; the long arm of the lever which 
 carries the weight o is then brought into the position n, and 
 the switch rail or point takes the position a (see detail C), 
 leaving the derailing switch open and protecting the main 
 track from runaway cars. 
 
 When, on the other hand, the switch is placed for the 
 siding E F, the tension on the wire is relaxed and the long 
 arm n of the derailing switch lever, being acted upon by the 
 
1124 
 
 TRACK WORK. 
 
 weight <?, is made to take the position n' , and the short arm 
 of the lever, the position ;;/'. This movement is transmitted 
 by the connection rod to the switch rail, which takes the 
 position a' (see detail C), securely closing the switch. The 
 guard rail e is secured to the main rail/ by two heavy bolts, 
 the space between them being maintained by a cast-iron 
 throat filler q. Near the derailing switch, a guard rail r is 
 placed, diverging from the outside rail, the object of which 
 is to prevent derailed cars from running on to the main line. 
 A heavy plank s is spiked to the ties close to the outside rail 
 to prevent any derailed trucks from turning up the rails. 
 
 1690. Automatic Turnouts. — For dummy or 
 street car roads using a light T rail, the automatic switch 
 
 Fig. 536. 
 
 shown in Fig. 536 may be used on turnouts, or passing 
 tracks, to great advantage. There are two switch points 
 a and b, one of which, a, is rigid, forming a combination of 
 frog and switch point. It consists of a guard rail r, two 
 throat fillers d and r, and the switch point a. The throat 
 fillers between the switch point and the head block unite, 
 forming a single filler, which is grooved at f. When 
 
TRACK WORK. 
 
 1125 
 
 approaching or leaving the switch, the wheel flange enters this 
 groove, bringing the wheel tread safely upon the stock 
 rail g-. 
 
 In America, at least, it is the universal custom for cars 
 approaching a passing track to take the right-hand track in 
 the direction indicated in the figure by the arrows m and n. 
 Accordingly the switch is always set for the right-hand 
 track, the switch point d being held firmly against the stock 
 rail /i by means of the iron rod k, which is acted upon by a 
 powerful spring confined in the shell /. This shell is spiked 
 to the head block between the rails, as shown in the figure, 
 and hence is not an obstruction to travel, as it would be if 
 placed outside the rails, and it is also comparatively safe 
 from injury from the wheels of heavy trucks and drays. 
 
 A car moving in the opposite direction, as indicated by 
 the arrows, throws the switch automatically. As the wheel 
 flanges come in contact with the switch rail d, the spiral 
 spring which holds the switch rail in place yields to the 
 pressure, and the switch opens, allowing the car to pass 
 from the siding to the main track. The wheel flanges, after 
 passing the switch point a, enter the groove /, before men- 
 tioned, and the wheel treads pass safely on to the stock rail 
 g: As the spring is constantly acting, each wheel throws 
 the switch, which closes the instant the wheel flange passes 
 the point. 
 
 Pig. 587. 
 
 There are three forms of turnouts, or passing tracks, in 
 general use; they are shown in Fig. 537, at A, B, and C, 
 
1126 
 
 TRACK WORK. 
 
 the arrows indicating the direction in which cars enter and 
 leave the turnout. It will be seen that some one of these 
 three forms of passing tracks will meet practically any given 
 situation. That shown at B is particularly suited to track 
 laid along the side of a street or highway, which may be 
 widened at the points requiring passing tracks. The form 
 shown at C should always be adopted for tracks laid on the 
 center line of streets. The extra room required for passing 
 tracks is equally distributed on both sides of the main center 
 line of the street, so that there will be the least possible 
 encroachment upon the space left for vehicles, 
 
 1691. Y Tracks. — The form of turnout shown in 
 Fig. 538 is called a Y. It is used as a substitute for a 
 
 Fig. 538. 
 
 turntable. Sometimes the switches are automatic, as shown 
 in the figure, in which case all locomotives must enter the Y 
 from the same end, viz., at a, and leave at b. Usually, 
 however, the switches are operated by hand levers and the 
 Y is entered from both directions. One special advantage 
 of a Y track is that both engine and train may be turned 
 together, and where favorably situated, they are much 
 used in shifting light trains which are run at frequent in- 
 tervals for the accommodation of suburban travel. 
 
TRACK WORK. 
 
 1127 
 
 1692. The Parts of a Turnout.— The several parts 
 of a turnout are represented in Fig, 539. The distance 
 //from the P. C. of the 
 turnout curve to the 
 point of frog is called 
 the frog distance. 
 The frog number and 
 frog angle we have al- 
 ready defined. The ra- 
 dius c o oi the turnout 
 curve, the frog distance, 
 the frog angle, and the 
 frog number bear cer- 
 tain relations to each 
 other, which are ex- 
 pressed by the following 
 formulas : fig. S39. 
 
 Tangent of half frog angle = gauge -t- frog distance. (11 4.) 
 Frog number = ^radius c o -^ twice the gauge. (11 5.) 
 
 Frog number = half the cotangent of half the frog angle. 
 
 (116.) 
 
 Radius c o:= twice the gauge X square of the frog number. 
 
 (117.) 
 
 Radius c o =^ {ffog distance p f -^ sine of frog atiglc) — ^ the 
 gauge. (118.) 
 
 Radius c o z=z gauge -i- {1 — cosine of frog angle') — ^ the 
 gauge. (119.) 
 
 Frog distance p f=- ffog number X tivice the gauge. ( 1 20.) 
 
 Frog distance p f z=. gauge p q -^ tangent of half the frog 
 attgle. (121.) 
 
 Frog distance p f = {radius c o -\- half the gauge) X sine of 
 frog angle. (122.) 
 
 Middle ordinate {approximate) = \ the gauge. (123.) 
 
1128 
 
 TRACK WORK. 
 
 Each side ordinate {approximate) = f the middle ordinate = 
 
 j%, (^'' • 188) of the gauge. (124.) 
 
 Switch length approximate = 
 
 ^ 
 
 throw infeetY. 10,000 
 
 tan deflection for chords of 100 ft. for radius c o of turnout cUrve. 
 
 (125.) 
 
 The tangent deflection may be obtained from the table 
 of Tangent and Chord Deflections. • 
 
 TABLE 35. 
 
 TURNOUTS FROM A STRAIGHT TRACK. 
 
 Gauge, Jf. feet 8^ inches. Throw of Switch, 5 inches. 
 
 Frog 
 
 Num- 
 ber. 
 
 Frog 
 Angle. 
 
 Turnout 
 Radius. 
 
 Degree 
 
 of 
 
 Turnout 
 
 Curve. 
 
 Frog 
 Dis- 
 tance. 
 
 Middle 
 Ordi- 
 nate. 
 
 Side 
 Ordi- 
 nate. 
 
 Stub 
 Switch 
 Length. 
 
 
 o / 
 
 Feet. 
 
 o , 
 
 Feet. 
 
 Feet. 
 
 Feet. 
 
 Feet. 
 
 12 
 
 4 46 
 
 1,356 
 
 4 14 
 
 113.0 
 
 1.177 
 
 .883 
 
 34 
 
 Hi 
 
 4 58 
 
 1,245 
 
 4 36 
 
 108.3 
 
 1.177 
 
 .883 
 
 32 
 
 11 
 
 5 12 
 
 1,139 
 
 5 02 
 
 103.6 
 
 1.177 
 
 .883 
 
 31 
 
 10^ 
 
 5 28 
 
 1,038 
 
 5 31 
 
 98.9 
 
 1.177 
 
 .883 
 
 29 
 
 10 
 
 5 44 
 
 942 
 
 6 05 
 
 94.2 
 
 1.177 
 
 .883 
 
 28 
 
 9i 
 
 6 02 
 
 850 
 
 6 45 
 
 89.5 
 
 1.177 
 
 .883 
 
 27 
 
 9 
 
 6 22 
 
 763 
 
 7 31 
 
 84.7 
 
 1.177 
 
 .883 
 
 25 
 
 8i 
 
 6 44 
 
 680 
 
 8 26 
 
 80.0 
 
 1.177 
 
 .883 
 
 24 
 
 8 
 
 7 10 
 
 603 
 
 9 31 
 
 75.3 
 
 1.177 
 
 .883 
 
 22 
 
 n 
 
 7 38 
 
 530 
 
 10 50 
 
 70.6 
 
 1.177 
 
 .883 
 
 21 
 
 7 
 
 8 10 
 
 • 461 
 
 12 27 
 
 65.9 
 
 1.177 
 
 .883 
 
 20 
 
 6i 
 
 8 48 
 
 398 
 
 14 26 
 
 61.2 
 
 1.177 
 
 .883 
 
 18 
 
 G 
 
 9 32 
 
 339 
 
 16 58 
 
 56.5 
 
 1.177 
 
 .883 
 
 17 
 
 H 
 
 10 24 
 
 285 
 
 20 13 
 
 51.8 1.177 
 
 .883 
 
 15 
 
 5 
 
 1126 
 
 235 
 
 24 32 
 
 47.1 1.177 
 
 .883 
 
 14 
 
 4^ 
 
 12 40 
 
 191 
 
 30 24 
 
 42.4 
 
 1.177 
 
 .883 
 
 13 
 
 4 
 
 14 14 
 
 151 
 
 38 46 
 
 37.7 
 
 1.177 
 
 .883 
 
 11 
 
TRACK WORK. 1139 
 
 The switch lengths in the above table merely denote the 
 shortest length of stub sivitch that will at the same time 
 form part of the turnout curve, and give 5 inches throw. 
 Pohit or split sivitchcs require a throw of not more than 3^ 
 inches, though many have a throw of 5 inches, with an 
 equal space between the gauge lines at the heel. The heels 
 of a split switch, which occupy the same position as the toes 
 of a stub switch, should be placed at the point where the 
 tangent deflection or offset is 5 inches. The point where 
 the tangent deflection is but 4^ inches will answer for many 
 rail sections, but for those above 65 lb. per yard, 5 inches 
 should be taken. 
 
 In the table of Tangent and Chord Deflections, tangent 
 deflections for chords of 100 feet are given for' all curves up 
 to 20°, and for a curve of higher degree, the tangent deflec- 
 tion may be found by applying formula 93, Art. 1255, 
 
 tan deflection = — ^. 
 
 In complicated track work where space is limited, curves 
 must be chosen to meet the existing conditions, and not 
 with reference to particular frog angles, in which case the 
 frogs are called special frogs, and are made to fit the par- 
 ticular curve used. The determination of the frog distance, 
 switch length, and frog angle may be understood by refer- 
 ring to Fig. 540. 
 
 Let the main track a b he 3. straight line; the gauge /^ = 
 4 feet Scinches (==4.71 feet) ; the degree of the turnout curve 
 = 13° ; the chord q d = 100 feet ; c d— the tangent deflection of 
 the chord q d, and// = the frog distance. From the table 
 of Tangents and Chord Deflections, we find the tangent deflec- 
 tion for a chord 100 feet long of a 13° curve is 11.32 feet. 
 
 Then, from Fig. 540, we have the proportion (see Art 
 
 1^^^) cd: efwYc-- T^- 
 
 Now, in curves of large radius q c and q d are assumed to 
 be equal. Also, q e^=.p f, the frog distance, and substitu- 
 ting these equivalents, we have the proportion 
 
 a . a 
 
 c d : e f '.'. q d \ p f . 
 
1130 
 
 TRACK WORK. 
 
 Substituting the above given quantities in the proportion, 
 
 we have ^ 
 
 11.32 : 4.71:: 100' ://; 
 
 whence, 
 
 // = 
 
 100' X 4.71 
 
 11.32 
 frog distance p f= 64. 5 feet. 
 
 and 
 
 If the space between the gauge lines of the rails at the 
 
 heels of a split switch 
 be taken at 5 inches = 
 0.42 of a foot, the dis- 
 tance from the P. C. 
 of the turnout curve 
 to the heel of the 
 switch may be found 
 \ as follows: 
 
 In Fig. 540, let h, 
 
 the tangent offset at 
 
 the heel of the switch 
 
 = 0.42 of a foot, and 
 
 "^-. \ we have the propor- 
 
 -----Ij 
 
 FIG. 540. 
 
 tion 
 c d 
 
 h'.'.q d '. q h ^ 
 
 and substituting known values, we have 
 11.32 : 0.42:: 100' :.^/; 
 
 whence, 
 
 qh = 
 
 « 10,000x0.42 
 
 =. 371.02, and 
 
 11.32 
 qh = 19.26 feet. 
 
 This locates the heel of a split switch and the toe of a stub 
 switch. 
 
 Th.Q frog angle is the angle k f I (see Fig. 540) formed by 
 the gauge line of the main rail f k and the tangent to the 
 outer rail q f oi the turnout curve at the point where the 
 two rails intersect. This angle is equal to the central 
 angle q o f. The arcs q /"and r s are assumed to be of the 
 same length. The turnout curve being 13°, the central 
 
TRACK WORK. 
 
 1131 
 
 1 Q \/ PC\ 
 
 angle for a chord of 1 foot is — = 7. 8', and the central 
 
 angle for 64.5 feet, the fro^ distance, is 7.8' X 64.5 = 8° 23', 
 the frog angle for a 13° curve. By this process the frog 
 distance, switch length, and frog angle may be calculated 
 for curves of any radius. 
 
 1693. To Lay Out a Turnout from a Curved 
 Main Track. — There are two cases: 
 
 Case I. — When the two curves deflect in opposite direc- 
 tions, illustrated by Fig. 541, and 
 
 d 
 
 ^iO 
 
 Fig. 541. 
 
 Case II. — When the two curves deflect in the same direc- 
 tion, illustrated in Fig. 542. 
 
 In Fig. 541, the curve a d is 3° 30', and it is proposed to 
 use a No. 8 frog. By reference to Table 35, we find that 
 the degree of curve 
 corresponding to a No. 
 8 frog is 9" 31'. Ac- 
 cordingly, we use a 
 turnout curve a e, 
 whose degree when 
 added to the degree of 
 curve of the main 
 track shall equal the 
 degree required for a 
 No. 8 frog, i. e., we 
 use a 6"^ turnout curve, 
 which is within one 
 minute of the required fig. 542. 
 
1132 TRACK WORK. 
 
 degree, and close enough for practical purposes. From our 
 knowledge of tangent and chord deflections we know that 
 for curves of moderate radii, i. e., from 1° up to 12°, the 
 tangent deflections or offsets increase as the degree of the 
 curve. That is, the tangent deflection of a 2°, 4°, and 
 G° curve is two, four and, six times, respectively, that of a 
 Incurve. In the accompanying figures illustrating the loca- 
 tion of frogs and switches, each curve is represented by two 
 lines indicating the rails, whereas only the center lines of 
 the curves are run in on the ground. In Fig. 541, the line 
 c d is tangent to the center lines of the curves. These center 
 lines do not appear in the cut. 
 
 Now, if, in Fig. 541, a tangent c d he drawn at c, the point 
 common to the center lines of the curves, the sum of the 
 deflections of both curves from the common tangent will be 
 equal to the tangent deflection of a 9° 30' curve from a 
 straight line. 
 
 Accordingly, to find the frog distance for a 6° turnout 
 curve from a 3° 30' 'curve, the curves being in opposite 
 directions, as shown in Fig. 541, we find the tangent deflec- 
 tion of a 9° 30' curve for a chord of 100 feet. This deflec- 
 tion is 8.28 feet (see table of Radii and Deflections). As- 
 suming the gauge of track to be standard, viz., 4 ft.^ 8^ in. = 
 4.71 ft., and denoting the required frog distance by x, we 
 have the following proportion: 
 
 8.28 : 4.71 :: 100' : x"; 
 
 , , 10,000X4.71 ^^oQ t A 
 whence, x^ = — —;^-^ = 5.688.4, and 
 
 o. /CO 
 
 frog distance x = 75.42 feet. 
 
 We use the tangent deflection for a 9° 30' curve, which is 
 practically the same as for a 9° 31' curve, and so save the 
 labor of a calculation, which will not appreciably affect the 
 result. 
 
 We locate the heel of the switch in the same way, using 
 for the second term of the proportion 0.42 foot, the dis- 
 tance between the gauge lines at the heel, instead of 4.71 
 feet, the gauge of the track. 
 
TRACK WORK. 1133 
 
 In Fig. 542, which comes under Case II, both curves de- 
 flect in the same direction, and the rate of their deflection 
 from each other is equal to the rate of the deflection of a 
 curve whose degree is equal to the difference of the degrees 
 of the two curves from a tangant. 
 
 Let the main track curve a b he: 5°, and the turnout curve 
 a c be 10°. Then the rate of deflection or divergence of 
 the 10° curve from the 5° curve is equal to the divergence 
 of a (10° — 5°) 5° curve from a straight track or tangent. 
 
 Accordingly, we find, in the table of Radii and Deflections, 
 the tangent deflection for a 5° curve for a chord of 100 feet = 
 4.36 feet. Denoting the required frog distance by x, we 
 have the following proportion : 
 
 4.36 : 4.71:: 100' : jr*; 
 
 whence, x^ = ^^'^.^^ ^"^^ = 10,802.8, and 
 
 4.30 
 
 frog distance x = 103.9 feet. 
 
 Distances are not calculated nearer than to tenths of feet. 
 
 1694. How to Lay Out a Switch. — In laying out a 
 switch, locate the frog so as to cut the least possible num- 
 ber of rails. Where there is some latitude in the choice of 
 location, the P. C. of the turnout curve can be located, so 
 as to bring the frog near the end of a rail. 
 
 To do this, take from Table 35 the frog distance cor- 
 responding to the number of the frog to be used. Locate 
 approximately the P. C. of the turnout curve, and measure 
 from it along the main track rail the tabular frog distance. 
 If this brings the frog point near the end of the rail, the 
 P. C. of the turnout curve may be moved so as to require 
 the cutting of dut one main track rail. Measure the total 
 length of the frog and deduct it from the length of the rail 
 to be cut, marking with red chalk on the flange of the rail 
 the point at which the rail is to be cut. Measure the width 
 of the frog at the heel and calculate the distance from the 
 heel to the theoretical point of frog. For example, if the 
 width of the frog at the heel is 8^ inches, and a No. 8 frog 
 
1134 TRACK WORK. 
 
 is to be used, the theoretical distance from the heel to the 
 point Qf frog is 8.5x8=08 inches = 5 feet 8 inches. 
 Measure off this distance from the point marking the heel 
 of the frog. This will locate the point of frog, which should 
 be distinctly marked with red chalk on the flange of the 
 rail. It is a common practice to make a distinct mark on 
 the web of the main track rail, directly opposite to the point 
 of frog. This point being under the head of the rail, it is 
 protected from wear and the weather. The P. C. of the 
 turnout curve is then located by measuring the frog dis- 
 tance from the point of frog. From Table 35 we find the 
 frog distance for a No. 8 frog is 75.3 feet, and the switch 
 length, i. e., the distance from the P. C. of the turnout 
 curve to the heel of the split switch or toe of the stub 
 switch, is 22 feet. 
 
 If a stub switch is to be laid, make a chalk mark on both 
 main track rails on a line marking the center of the head 
 block. A more permanent mark is made with a center 
 punch. Stretch a cord touching these marks, and drive a 
 stake on each side of the track, with a tack in each. This 
 line should be at right angles to the center line of the track, 
 and the stakes should be far enough from the track as not 
 to be disturbed when puttmg in switch ties. Next, cut the 
 switch ties of proper length; draw the spikes from the track 
 ties, three or four at a time, and remove them from the 
 track, replacing them with switch ties, and tamping them 
 securely in place. When all the long ties are bedded, cut 
 the main track rail for the frog, being careful that the 
 amount cut off is just equal to the length of the frog. If, 
 by increasing or decreasing the length of the lead 5 per 
 cent, you can avoid cutting a rail, do not hesitate to do so, 
 especially for frogs above No. 8. 
 
 Use full length rails (30 feet) for moving or switch rails, 
 and be careful to leave a joint of proper width at the head 
 chair. Spike the head chairs to the head block so that the 
 main track rails will be in perfect line. Spike from 8 to 
 10 feet of the switch rails to the ties, and slide the cross 
 rods on to the rail flanges, spacing them at equal intervals. 
 
TRACK WORK. 
 
 1135 
 
 The cross rods are placed between the switch ties, which 
 should not be more than 15 inches from center to center of 
 tie. The switch ties, especially those under the moving 
 rails, should be of sawed oak timber. Southern pine is a 
 good second choice. Attach the connection rod to the head 
 rod and to the switch stand. With these connections made, 
 it is an easy matter to place the switch stand so as to give 
 the proper throw of the switch. 
 
 It is common practice to fasten the switch stand to the 
 head block with track spikes, but a better fastening is made 
 with bolts. The stand is first properly placed and the holes 
 marked and bored, and the bolts passed through from the 
 under side of the head block. This obviates all danger of 
 movement of the switch stand in fastening, which is liable 
 to occur when spikes are used, and insures a perfect throw. 
 
 The use of track spikes is quite admissible when holes are 
 bored to receive them, in which case a half-inch auger 
 should be used for standard track spikes. The switch stand 
 should, when possible, be placed facing the switch, so as to 
 be seen from the engineer's side of the engine — the right- 
 hand side. 
 
 Next stretch a cord from ^, Fig. 543, a point on the outer 
 main track rail opposite the P. C. of the 
 turnout curve, to b^ the point of the frog. 
 This cord will take the position of the chord 
 of the arc of the outer rail of the turnout 
 curve. Mark the middle point c and the 
 quarter points d and e. Whatever the 
 degree of the turnout curve, the distance 
 from the middle point c of the chord to the 
 arc a b 'v& 1.18 feet, and the distances from 
 the quarter points d and e are .88 foot; al 
 hence, at c lay off the ordinate 1.18 feet, 
 and at both d^and e the ordinate .88 foot, 
 three-quarters of the middle ordinate. 
 These offsets will mark the gauge line of 
 the rail a b. Add to these offsets the dis- 
 tance from the gauge line to outside of the rail flange, 
 
 Fig. 543. 
 
1136 TRACK WORK. 
 
 and mark the points on the switch ties. Spike a lead rail 
 to these marks and place the other at easy track gauge from it. 
 Spike the rails of the turnout as far as the point of frog to 
 exact gauge, unless the gauge has been widened owing to 
 the sharpness of the curve. Beyond the point of frog the 
 curve may be allowed to vary a little in gauge to prevent a 
 kink showing opposite the frog. In case the gauge is 
 widened at the frog, increase the guard rail distance an 
 equal amount. For a gauge of 4 feet 8^ inches, place the 
 side of the guard rail which comes in contact with the car 
 wheels at 4 feet G| inches from the gauge line of the frog. 
 This gives a space of 1|- inches between the main rail and 
 the guard rail. 
 
 In case the gauge is widened :^ or ^ inch, increase the 
 guard rail distance an equal amount. 
 
 When the turnout curve is very sharp, it will be neces- 
 sary to curve the switch rails, to avoid an angle at the 
 head block. The lead rails should be carefully curved be- 
 fore being laid, and great pains taken to secure a perfect 
 line. 
 
 If 2i point, or split, switch is to be laid, the order of work 
 is nearly the same. The same precautions must be taken to 
 avoid the unnecessary cutting of rails, with the additional 
 precaution of keeping the switch points clear of rail joints, 
 as the bolts and angle splices will prevent the switch points 
 from lying close to the stock rails. As already stated, 
 these conditions can usually be met where there is some 
 range in the choice of the location of the switch. Where 
 there is none, the main track rails must be cut to fit the 
 switch. 
 
 Having located the point of frog, the P. C. of the turnout 
 curve, and the heel line of the switch, measure back from the 
 heel line a distance equal to the length of the switch rails, 
 and place on the flange of each rail a chalk mark to locate 
 the ends of the switch points. This will also locate the head 
 block. Prepare switch ties, of the requisite number and 
 length, and place them in the track in proper order. As in 
 
TRACK WORK. 1137 
 
 the case of stub switches, see to it that all long switch ties 
 are in place before cutting the rail for placing the frog; 
 also, that the ends of the lead rails, with which the switch 
 points connect, are exactly even ; otherwise the switch rods 
 will be skewed, and the switch will not work or fit well. 
 Fasten the switch rodsjn place, being careful to place them 
 in their proper order, the head rod being No. 1. Each rod 
 is marked with a center punch, the number of the punch 
 marks corresponding to the number of the rod. 
 
 Couple the switch points with the lead rails and place the 
 sliding plates in position, securely spiking them to the ties. 
 Connect the head rod with the switch stand, and close the 
 switch, giving a clear main track. 
 
 Adjust the stand for this position of the switch, and bolt 
 it fast to the head block. Next, crowd the stock rail against 
 the switch point so as to insure a close fit, and secure it in 
 place with a rail brace at each tie; then continue the laying 
 of the rails of the turnout. 
 
 If there is no engineer to lay out the center line of the 
 turnout, the section foreman can put in the lead from or- 
 dinates, as explained in Fig. 543. In modern railroad prac- 
 tice, however, most track work is done under the direction 
 of an engineer, in which case the center line of the turnout 
 is located with a transit. This ensures a correct line and ex- 
 pedites work. For ordinary curves, center stakes at inter- 
 vals of 50 feet are sufficient, excepting between the P. C. of 
 the turnout and the point of frog, where there should be a 
 center stake at each interval of 25 feet. Place a guard rail 
 opposite the point of frog on both main track and turnout. 
 The guard rail should be 10 feet in length; this is an 
 economical length for cutting rails, as each full-length rail 
 makes three guard rails. 
 
 Two styles of guard rails are shown in Fig. 544. That 
 shown at B is in general use, but the style shown at A is 
 growing in favor. 
 
 The latter is curved throughout its entire length. At its 
 middle point a^ directly opposite the point of frog, the 
 
1138 
 
 TRACK WORK. 
 
 guard rail is spaced 1|- inches from the gauge line of the 
 turnout rail b c. From this point the guard rail diverges in 
 both directions, giving at each end a flange-way of 4 inches. 
 This allows the wheels full play, excepting at the point of 
 frog, where the guard rail is exactly 
 adjusted to the track gauge, and holds 
 the wheels in true line, preventing them 
 from climbing or mounting the frog. 
 The style of guard rail shown at B^ 
 though still much used, has two ob- 
 jectionable features, viz., first, the 
 abruptly curved ends d and e often re- 
 ceive an almost direct blow from the 
 wheel flanges, which causes a car to 
 lurch violently; and second, the flangCr 
 way of uniform width, though proper 
 for the main track when straight, as 
 in Fig. 544, is unsuited for sharp curves 
 on either a main track or a turnout, as 
 it compels the wheels to follow a curved 
 line; whereas, the normal position of 
 the wheel base of each truck is that of a chord of, or a tan- 
 gent to, the curve. These two defects alone produce what 
 is known as a rough-riding frog, even though the frog is 
 well lined and ballasted. 
 
 It is customary to bend the stock rail with a rail bender in 
 the proportion of about 1 to 40, placing the angle about 10 
 inches back from the switch points, so that the beveled 
 points will lie snugly against the stock rail. Exception to 
 this rule is found in the practice of the Philadelphia and 
 Reading R. R., where the switch points are curved so as to 
 fit the stock rail, which is not bent at the switch point, but 
 laid to an exact curve. 
 
 The custom of half spiking side tracks should be con- 
 demned as unsafe and very poor economy. Side tracks 
 should receive as thorough work as the main line, though, of 
 course, they require less of it. This point has been touched 
 upon before. 
 
 Pig. 644. 
 
TRACK WORK. 1139 
 
 1695. Laying Frogs in Track. — In placing a frog 
 in the track, special care should be taken to put it in perfect 
 line and surface with the rails with which it connects. 
 Couple the frog to the main track rails and put them in perfect 
 line before spiking. This is more certain to give a true line 
 to the frog than to spike the connecting rails before coupling 
 with the frog. If the main track is in poor line, put in track 
 centers for lining the frog, for it is very difficult to correct 
 defects in line after a switch is once in place. Having spiked 
 the frog in place, put the rail opposite the frog in perfect 
 gauge for the full length of the frog, if on a tangent, and at 
 the point of frog, if on a curve. To have a frog in perfect 
 gauge, try the gauge at each end of the frog, and at about 
 six inches back of the frog point. 
 
 If the curve is very sharp and laid to a uniform gauge 
 throughout, an ugly kink is left opposite the frog. This 
 defect is caused by the frog rail, which is necessarily straight, 
 and can be remedied by spiking the rail to gauge ojily 
 at the point of frog, and allowing it to assume its natural 
 curve for the remainder of the frog's length. 
 
 Turnout curves of long radii require long frogs, and the 
 track can be spiked to proper gauge throughout its length 
 without any perceptible kink at the frog. 
 
 Long frogs and long leads are the best where it is practi- 
 cable to use them. The wear from sharp curves and short 
 frogs, both upon rails and rolling stock, is great, and 
 they are to be used only where limited space requires 
 them. 
 
 1696. Switch Timbers. — Every first-class railroad 
 has its own standards for switches, which include the neces- 
 sary switch timbers. The following rule will answer well 
 for general use: 
 
 Rule. — To find the number of tics required for any switch 
 lead, reduce to inches the distance from the head-block to the 
 last long tic behind the frdg, and divide this distance by the 
 number of inches from center to center of tie; the quotient 
 ivill be the number of ties required. 
 
1140 TRACK WORK. 
 
 Example. — The distance from the head block to the last tie behind 
 the frog is 77 feet. The ties are spaced 21 inches center to center. 
 What is the number of ties required for the switch ? 
 
 Solution.— 77 feet = 924 inches; 924 h- 21 = 44, the number of ties 
 required. Ans. 
 
 Switch ties should be 10 inches in width and at least G 
 inches in thickness, though 7 inches is preferable. The 
 head-block should be 12 inches in width and 8 inches in 
 thickness, and 16 feet in length. When timber may be 
 furnished in odd lengths, the following list will furnish the 
 necessary timber for a given switch, which is a single throw, 
 and requiring a No. 8 frog: 
 
 SWITCH TIES 21 INCHES TO CENTER. 
 
 1 head-block 8" X 12" X 16' long. 
 
 8 pieces 6" X 10" X 9' long. 
 
 8 pieces 6" X 10" X 10' long. 
 
 8 pieces 6" X 10" X 11' long. 
 
 5 pieces 6" X 10" X 12' long. 
 
 5 pieces 6" X 10" X 13' long. 
 
 5 pieces 6" X 10" X 14' long. 
 
 3 pieces 6" X 10" X 15' long. 
 
 When even lengths only can be ordered, the list must be 
 modified, only care must be taken to have the timber long 
 enough. 
 
 Switch ties in important yards should not be more than 9 
 inches apart, if they are to be kept in proper surface. It is 
 poor economy to use inferior timber for switch ties, or a scant 
 number of ties. Switch building is expensive work, and 
 should be made as permanent as is practicable. 
 
 To cut switch ties the proper length apply the following 
 rule: 
 
 Rule. — Measure the length of the tie next the head block 
 and the length of the last long tie behind the frog. Find the 
 difference in inches betiveen them. Divide this difference by 
 the number of ties in the sioiteh lead ; the quotient i^'ill be the 
 increase in length per tie from the head block towards the frog 
 
TRACK WORK. 1141 
 
 to have the ends of the ties in proper line on both sides of the 
 track. 
 
 Example. — The length of the tie next the head block is 
 8 feet 6 inches = 102 inches. The length of the last tie 
 behind the frog is 15 feet = 180 inches. The difference 
 between the lengths of the ties, 180 — 102 = 78 inches, 
 which, divided by 44, the required number of ties, gives 1.8, 
 say If inches, the average increase in length per tie. 
 
 There is nothing gained by giving to switch ties a greater 
 projection outside the rails than ordinary track ties. They 
 add to the labor of raising the track, are unsightly, and 
 labor is wasted in tamping up the long ends. The switch 
 ties should be cut to proper length, marked with chalk in 
 consecutive numbers, and a mark for the outside flange of 
 the main track rail placed on each tie for lining them. Any 
 one acquainted with track work knows that the labor 
 of cutting ties to exact length, numbering them, and mark- 
 ing them for proper lining is labor saved. There is then 
 no time wasted in cutting and trying; the work can be 
 pushed from start to finish, and the result is a perfect piece 
 of work. 
 
 1697. Tamping Switch Ties. — Before tamping up 
 a set of switch ties, raise the track to a uniform surface. 
 Tamp the ties under the frog and main track rail first, rais- 
 ing the frog a shade higher than the rest of the switch. 
 The head block should also be about one-quarter of an inch 
 above the common surface, especially if a stub switch, as 
 the continual jarring caused by wheels passing the open 
 joint will cause the head block to settle slightly. Tamp up 
 the middle of the ties first and then the outer ends. This 
 will prevent any sagging of the ties at center and a corre- 
 sponding rise at the ends. If possible, complete the tamp- 
 ing before a train passes the switch. 
 
 1698. Three-Throw Switch Timbers. — The 
 
 lengths of switch timbers for a three-throw switch are found 
 by doubling the lengths of those for a single turnout, and 
 subtracting from each the length of the standard cross-tie, 
 
1142 
 
 TRACK WORK. 
 
 Before placing them in the switch, draw a chalk line across 
 the middle of each tie, and number them in the same order 
 as in a single turnout. Then, place them under the main 
 track rail, and make the middle mark of each switch tie 
 coincide with the middle point of the track gauge placed on 
 the main track above the tie. 
 
 1 699. Location of Crotch Frog. — A crotch, or mid- 
 dle, frog is a frog placed at the point where the outer rails 
 of both turnouts of a three-throw switch cross each other. 
 When both turnouts are of the same degree, the crotch frog 
 comes midway between the main track rails. Its location 
 and angle may be determined as follows : Let the turnout 
 curves A and B, Fig, 545, be each 9° 30', uniting with the 
 
 Fig. 545. 
 
 main track C by a three-throw switch. Let a be the P. C. 
 
 common to both curves, and d, the location of the crotch or 
 
 middle frog. 
 
 It is evident that the point of the crotch frog should be 
 
 exactly midway between the gauge lines of the main track 
 
 rails, and if the gauge is 4 feet 8^ inches = 4.71 feet, the 
 
 4 71 
 pomt of the crotch frog will be — -— = 2.35 feet from each 
 
 rail. Now, the problem is to find the frog distance from a, 
 the P. C, to the point c, where the tangent deflection will 
 equal 2.35, or half the gauge. From the table of Radii and 
 Deflections, we find the tangent deflection of a 9° 30' curve 
 is 8.28 feet. Applying the principle explained in Art. 1692 
 
TRACK WORK. 1143 
 
 and Fig. 540, and letting x represent the required frog dis- 
 tance, we have the following proportion: 
 
 8.28 : 2.35:: 100' :;r'; 
 
 whence, x"" = l^^l^Al^ = 2,838.2 feet, 
 
 8. Zo 
 
 and X = 53.3 feet, nearly, 
 
 the required frog distance. 
 
 Now, there are two curves starting at the common point a ; 
 
 the outer rails intersect at If,. and the angle d b c, formed by 
 
 tangents drawn to the point of intersection, is the angle of 
 
 the crotch or middle frog. The angle is equal to the sum 
 
 of the angles a f b and a f b\ that is, equal to double the 
 
 central angle of either curve between the P. C. and the point 
 
 of intersection b. The degree of the curve is 9" 30' = 5?0', 
 
 570' 
 and the central angle or total deflection for each foot is -— = 
 
 5.7', and for the frog distance of 53.3 feet, the central 
 angle is 53.3 X 5.7 = 303.8' = 5"* 03.8'. The angle of the 
 crotch frog is double this angle, i. e., 5° 03.8' X 2= 10° 
 07. G'. The crotch frog should be accurately located and 
 spiked in place before the lead rails are placed. 
 
 The one objection to the three-throw switch is the open 
 joint at the head block, the inevitable attendant of the stub 
 switch, but its advantages are so great that it will continue 
 to be used, especially in yard service. 
 
 1 700. Cross-Over Tracks. — A cross-over is a track 
 by means of which a train passes from one track to another. 
 The tracks united are usually parallel, as are the tracks of 
 a double track road. Such a cross-over is shown in Fig. 
 540. The tracks a b and c d are 13 feet apart from center to 
 center, which is the standard distance for double tracks. 
 The cross-over consists of two turnout curves, e f and ^ h. 
 These curves are usually, though not necessarily, of the 
 same, degree. The curve terminates at the points of frog/" 
 and //, between which the track f h is a tangent. The 
 essential point in laying out a cross-over is to so place the 
 
1144 TRACK WORK. 
 
 frogs that the connecting track shall be tangent to both 
 cu^'ves. In Fig. 546, suppose the frogs are No. 9, requiring 
 7° 31' turnout curves. 
 
 From Table 35, we find the required frog distance is 
 84.7 feet, and the switch length 25 feet. As previously 
 noted, if there is considerable range in choice of location, 
 the frogs can be so placed as to largely avoid the cutting of 
 rails; but usually cross-overs are required at certain precise 
 places, and the rails must be cut as occasion demands. 
 Having located the point of frog at /, we determine the 
 point of the next frog at /z, as follows: A No. 9 frog is one 
 
 Fig. 546. 
 
 which spreads 1 inch in width to every 9 inches in length, 
 and as the track between the frog points is straight, the 
 distance / Jl between these points will be as many times 
 9 inches as is the space k between the tracks at the frog point 
 f. The main track centers are 13 feet apart, making the 
 space between the gauge lines of the inside rails 8 feet 
 3^' inches. As it is the rail / of the turnout which joins the 
 second frog at h, we subtract the gauge, 4 feet 8^ inches, 
 from 8 feet 3^ inches, leaving 3 feet 7 inches, the distance k, 
 between the gauge line of the rail /, opposite the frog point 
 y, and the gauge line of the nearest rail of the track c d. 
 This distance multiplied by 9 inches will give the distance 
 from the frog point f to the frog point // ; 3 feet 7 inches 
 = 43 inches, 43 X 9 = 387 inches = 32 feet 3 inches. Ac- 
 cordingly having located the point of frog /", we mark a 
 corresponding point on the nearest rail of the opposite track. 
 From this point we measure along the rail the distance 32 
 feet 3 inches, locating the second frog point //, and again the 
 frog distance 84.7 feet to the P. C. of the second turnout 
 curve at g. 
 
 If frogs of different numbers, say 7 and 9, were to 
 
Mr. 
 
 r 
 
TRACK WORK. 1145 
 
 be used, the distance between the frogs is found as fol- 
 lows: 
 
 As the No. 7 frog spreads 1 inch in 7 inches, and the No. 9 
 frog 1 inch in 9 inches, the two will together spread 2 inches 
 in 7 + 9 = 16 inches, or 1 inch in 8 inches. Now, if the rails 
 to be united are 3 feet 7 inches, or 43 inches apart, as in the 
 previous problem, the distance between the frog points will 
 be 43 X 8 = 344 inches = 28 feet 8 inches. 
 
 In locating cross-over tracks, regard should be paid 
 to the direction in which the bulk of the traffic moves, 
 and the cross-over tracks should be so placed that loaded 
 cars will be backed, not pushed, from one track to the 
 other. 
 
 At all stations on double track roads there should be a 
 cross-over to facilitate the exchange of cars and the making 
 up of trains. 
 
 YARDS AND TERMINALS. 
 
 1701. This subject includes the laying out and main- 
 tenance of the extensive railway yards which are found at 
 all terminal and division points. 
 
 A terminal to be effective must provide ample track room 
 for all cars being stored, unloaded, or exchanged, with the 
 tracks so arranged that terminal business may be transacted 
 with facility and dispatch. To save time is to save money 
 in all departments of a railroad. Much time is unavoidably 
 consumed in transferring cars to foreign lines, making up 
 trains, and shifting cars to freight depots or side tracks for 
 unloading; but a badly arranged yard involves waste of 
 time and increased forces of men and engines. Hence, the 
 laying out of yards and terminals should be placed in the 
 hands of men of judgment and large experience. Further- 
 more, a railroad company can well afford to incur large 
 expenditure in first cost if they thereby avoid the con- 
 tinual extra expense due to badly arranged yards and 
 terminals. 
 
 A well-arranged terminal is shown in Fig. 547, in which 
 practically all the requirements for local and through traffic 
 
1146 TRACK WORK. 
 
 and for traffic exchange, both by rail and water, are fully 
 met. 
 
 The railroad has a double track, a a' and b b' . The 
 passenger station A is placed where two important streets 
 intersect, and should be as near the center of population 
 and business as is practicable. This station combines two 
 buildings, the one c in front, containing the passenger, 
 baggage, and express rooms on the first floor and the general 
 offices of the company on the upper floors. The rear build- 
 ing rtT is a train shed, and contains six tracks, with platforms 
 between. These platforms should be from 8 to 10 feet in 
 width, so that passengers need not crowd each other while 
 taking the cars. In many of the best stations, these plat- 
 forms are of concrete, finished smooth with Portland cement. 
 This makes an excellent walk, is fireproof and enduring. 
 The roof should be of iron, and the entire station made 
 fireproof, if practicable. 
 
 Empty passenger coaches are stored on the tracks ^, con- 
 venient to the station. The freight station and offices are 
 shown at B. This station is in four parts. The first part 
 y, in front, contains the freight offices, and is usually two or 
 three stories in height. The parts g and // are freight 
 rooms for receiving and discharging freight. The part k is 
 a train shed, containing six tracks, allowing three rows or 
 banks of cars for each freight room. The cars are backed 
 into the train shed with the car doors on each track on line 
 with those on the adjoining tracks. Bridges of either planks 
 . or sheet iron extend from car door to car door, so that two 
 or three rows of cars may be loaded at the same time. By 
 this means a way freight train for a long line with numer- 
 ous stations may be loaded with dispatch and without 
 confusion. 
 
 The freight rooms have no outside platforms. Drays 
 loaded with outgoing freight back up to the doors of the 
 freight room; the freight is discharged directly into the 
 freight room, and often is carried by trucks directly from 
 the drays to the car. This saves the delay and expense of 
 rehandling, which would result from discharging from 
 
'Track work. lut 
 
 drays to a platform. Trains of local freight are stored on 
 the tracks / while awaiting their turn for unloading, and 
 cars laden with outgoing- freight may be stored on the 
 tracks in until a train is made up. 
 
 It will be observed that the main tracks a a! and b b' are 
 comparatively free from switches, excepting at the pas- 
 senger train yard and station. All tracks entering the 
 passenger station A connect with the outbound track b b' . 
 All the tracks connecting with the freight station B are 
 thrown from the main stem track ;/, which connects with 
 the outbound main track b b' . The streets o and/, adjoin- 
 ing the freight station, are extended to accommodate drays 
 or other vehicles while unloading freight in car lots from 
 the adjoming sidings. 
 
 The track ^ r is sometimes called a ladder track. It runs 
 diagonally across the yard, intersecting all tracks and con- 
 necting with each by means of slip switches, shown in detail 
 at A' and B' . This track extends to the steamship wharves 
 C and D. Two tracks run alongside each pier, the tracks 
 being depressed so as to bring the car floors nearly on a 
 level with the deck of the pier. The passenger room and 
 steamship offices are at E. Additional side tracks for local 
 freight in car lots are shown at s and /. Additional rail- 
 road wharves are shown at F, G, and H. Wharves should 
 be covered with strong sheds, and when the pier foundation 
 is of stone or creosoted piles, it is economy to build the shed 
 of iron. Grain elevators are shown at / and K. The 
 tracks, five in number, run between the elevators, giving 
 abundant dockage for ships on either side. 
 
 The wharves Z, M, N, O, P, and Q are for coal traffic. 
 The piers support coal pockets, which have sufficient eleva- 
 tion to cause the coal to run by gravity into the holds of 
 vessels lying alongside. The track v, connecting with the 
 main track b b\ has an ascending grade not to exceed 2 per 
 cent., which gives sufficient elevation to the spur tracks 
 running on to the coal wharves. 
 
 Track x^ connecting with the elevated track v, leads to a 
 coal chute R. The buildings shown at S, T, and U are 
 
1148 TRACK WORK. 
 
 warehouses, where freight is stored in bond or otherwise 
 for future deHvery. A foundry is represented by J\ a car 
 shop by IV, a machine shop by A', a roun'd house with turn- 
 table by V, and a chute for coaling engines by Z. The 
 engine and boiler house j is so situated that it can supply 
 steam to foundry, car, and machine shops. Track r, as well 
 as (/ r, is a ladder track. The tracks C are for outgoing 
 trains and for cars to be transferred to foreign lines. 
 Tracks D' are for storing local and steamship freight. 
 Tracks approach the turntable at V from both directions, 
 which saves time and switching. Cross-overs are placed at 
 the points where there is frequent shifting of cars from one 
 track to another. The slip switches, shown at A' and /?' in 
 detail A, combine economy of space with great flexibility 
 and greatly simplify the work of shifting cars and making 
 up trains. 
 
 GENERAL INSTRUCTIOXS. 
 
 1702. Inspecting a Section from a Car or 
 Engine. — Section foremen should occasionally ride over 
 their section either on an engine, a caboose, or the rear car 
 of a passenger train, and note carefully the action of the 
 car while passing over the track. A defect in line or sur- 
 face, which would scarcely have any effect upon a car run- 
 ning 20 miles an hour, would cause one running at a speed 
 of 45 miles an hour to lurch violently. This is owing to 
 the fact that a speed of 20 miles an hour will permit a car 
 to become righted after passing one defect before coming to 
 a second, while a car running at a speed of 45 miles an 
 hour may encounter several defects in line or surface in a 
 second of time. 
 
 If a car lurches badly when passing over a straight line, 
 the track at that spot is either low or badly out of gauge. 
 If, in passing over a curve, the car swings to the outside of 
 the curve, there is not sufficient elevation to the outer rail, 
 but if the car swings towards the inside of the curve, there 
 is too much elevation in the outer rail at that place. 
 
TRACK WORK. 1149 
 
 An observing, alert man will soon become expert in 
 detecting the different movements of the c^r as it swings 
 to either side of the track, and should determine the cause 
 by walking over the track immediately after riding over it, 
 and remedy the defects in the track. 
 
 1 703. Avoid Attaching Hand or Pusb Cars to 
 Trains. — Foremen should never attach a hand or push car 
 to a train to avoid the labor of pumping or pushing the car 
 to its destination. Many serious accidents have resulted 
 from such action. The sudden slackening or stopping of a 
 train is likely to throw the hand or push car under the train 
 in spite of every effort to prevent it, and serious injury, if 
 not death, is the sure result. 
 
 1704. Al^vays Carry a Track JTack. — Foremen 
 should never be out on their sections without a track jack. 
 Keep it on the hand car when not in use, so it will always be 
 available. In no way is time oftener wasted than in 
 attempting to raise a rail with a makeshift lever when the 
 track jack has been left behind at the section house. Fre- 
 quently, the spikes are drawn from the ties and the track 
 marred both in gauge and surface by it. 
 
 The track jack is one of the best and most economical 
 tools in use upon a railroad, and every section should 
 possess one and make the utmost use of it. 
 
 1 705. The Track Level. — Always carry a track level 
 when going out on the section to pick up or surface track. 
 It is useless to attempt to surface track without a spirit 
 level, though low spots in a track which has once been put 
 in good surface may be put in proper surface by sighting. 
 
 1 706. Rails of Different Heights.— Where rails of 
 different heights meet at a joint, they should be connected 
 by a step splice, and an iron shim should be placed under the 
 low rail, to bring the tops of both rails to the same level. 
 The shim should be slotted at the sides, and spikes driven 
 through the slots, to hold the shim in place. 
 
iloO TRACK WORK. 
 
 1707. Extra Men. — When a section foreman is about 
 to largely increase his force for temporary work, he should 
 take time to carefully plan his work and the disposition of 
 his men. Work well organized is half done. 
 
 1708. Getting Acquainted with tlie Section.— 
 
 Every section foreman should, immediately upon taking 
 charge of his section, thoroughly acquaint himself with 
 everything connected with it and his work. He should 
 know the length of his section, the location and degree of 
 each curve, the number and location of each bridge, trestle, 
 cattle guard, crossing, and culvert, the weight, brand, and 
 age of all steel and its location, the number of panels of 
 snow fence, the height of bridges from the ground, the loca- 
 tion of whistling posts, the numbers of all frogs, and any 
 information which can assist a foreman in making out 
 correct and prompt reports to the roadmaster. 
 
 1709. Drilling Rails. — When it is necessary to cut 
 rails in putting in switches, or in repairing track, the rails 
 should be full drilled and bolted at every joint. A joint but 
 half bolted is sure to sag in a short space of time. 
 
 1710. Lining Disconnected Track. — When lining 
 disconnected track that has been washed out, always com- 
 mence at the connected end, else it will be practically 
 impossible to get the track in line. 
 
 1711. Cutting Steel. — Section foremen should care- 
 fully instruct their men how to cut rails. The cut of the 
 chisel should be a continuous line extending entirely around 
 and square across the rail. Iron rails require deeper cutting 
 than steel rails. To break off a rail at the cut, lift up the 
 end nearest the cut and let it fall across a piece of rail laid 
 on a tie. If but a short piece of the rail is to be broken off, a 
 sharp blow from a sledge is the surest way to break it. 
 Hard steel, if cut too deep, is liable to become softened by 
 the battering of the chisel, and in breaking leave a rough, 
 unshapely end on the rail. A spike maul should not be 
 used to strike the head of either chisel or punch, as it is 
 
TRACK WORK. 1151 
 
 sure to destroy the face of the maul and split pieces out of 
 the head of steel tools. A sledge of suitable weight, made 
 for the purpose of striking hard steel tools, should be used 
 instead. 
 
 Cold chisels when first dressed by the blacksmith are 
 not always well tempered at the point, and in using a newly 
 sharpened chisel, light and careful blows should be given 
 first. If the tool is well tempered, the edge will hold, but 
 if poorly tempered, the edge will chip slightly. The chisel 
 should then be ground to a true edge, which generally 
 toughens it, and it will cut a number of rails before it is 
 necessary to send it to the shop again. 
 
 1712. Distance at Which to Place Danger Sig- 
 nals. — Danger signals should be placed at distances not 
 less than 3,500 feet in each direction from the point where 
 the track is impassable for trains. The distance can be 
 measured by counting 117 rails of 30 feet each from the 
 point of danger, or, where the telegraph poles are 150 feet 
 apart, place the signals 23 poles distant from the point of 
 danger. If the point of danger is at the foot of a heavy 
 grade, where it is difficult to stop a train, the distance of 
 the danger signal should be increased to even double the 
 ordinary distance, or the telegraph operator at the nearest 
 station informed of the danger, so that he may notify the 
 train dispatcher, who will at once warn all trains within 
 danger, and they can be held until the track is safe for 
 their passage. Where there is a suflficient force of men to 
 make repairs, the flagman should remain with the danger 
 signal until the track is repaired or the train stopped. 
 In foggy or stormy weather, the flagman imist ahi>ays 
 remain out with the signals until all danger is passed. 
 As soon as the track is safe for the passage of trains, 
 flags, torpedoes, or other signals should be removed at 
 once. 
 
 Foremen should always carry flags and torpedoes on 
 their hand cars, and fully instruct their men in the use of 
 them. They should be fully posted on the time of all 
 
1152 TRACK WORK. 
 
 regular trains, and should be on the watch for signals 
 carried by regular trains. 
 
 1713. Signals. — In setting a signal requiring a train 
 to run slowly, called a slow flag, place the flag on the 
 engineer's side of the tracks the right hand side, slightly 
 leaning, so that most of it can be seen, and just far enough 
 from the rail to clear the engine and cars. 
 
 A slow signal is set out one-half mile, about 17 telegraph 
 poles, distant. 
 
 A red flag or light, which is a stop signal, should be placed 
 in the center of the track. Two torpedoes should be 
 placed on the same rail, about 60 feet apart, between the 
 stop signal and the approaching train. 
 
 1714. Location of Whistling Posts and Signs. — 
 
 Station whistling posts should be placed one-half mile out- 
 side the switch, not the depot, and on the engineer's side 
 (the right side) of the track to one approaching the station. 
 Station mile boards should be placed one mile outside the 
 switches. If the post were placed but one mile from the 
 station, it would, in large yards, often fall inside the 
 switches. The object of these signs is to warn trainmen of 
 the near approach of a station in order that they may have 
 the train under control before reaching the station. 
 
 Whistling posts for highways should be placed one-quarter 
 of a mile from the crossing, and on the engineer's side of 
 the track. Whistling posts or other signs should never be 
 placed in a cut where they will not be readily seen. If on 
 a descending grade, place the sign- outside the cut, increas- 
 ing the distance; if on an ascending grade, decrease the 
 distance. This rule also applies to sharp curves. All 
 signs carrying a cross-board should have the board placed 
 at right angles to the track. Highway crossing signs 
 should be placed parallel to the rails, so that they may be 
 distinctly read by persons approaching the track. All posts 
 carrying signs should be vertical, and securely set in the 
 ground, and so placed as not to come in contact with either 
 trains or vehicles. 
 
TRACK WORK. 1153 
 
 1715. Obstructing the Track. — The track should 
 never be so used as to obstruct a regular train, nor should 
 any work be undertaken which can not be finished, and the 
 track made safe, fully 15 minutes before the train is due. 
 In case of a delayed passenger train, the track must be 
 kept constantly safe and clear, and if repairs must be 
 made, a responsible man, preferably the foreman himself, 
 should remain out with signals until the track is safe and 
 clear. 
 
 Some foremen have a habit of leaving the hand or push 
 car on the track while repairs are being made. This is a 
 dangerous practice, and contrary to the rules of any well- 
 managed railroad. The hand car should not only be kept 
 clear of the track when not in use, but should not be left in 
 the way of road or farm crossings. 
 
 1716. Hand-Car and Tool Houses. — Hand car and 
 tool houses should be placed outside the switches at yards 
 and stations, so that trains standing on the side track will 
 not deter section men with their hand car from going to 
 work. Tool houses must be far enough from the track to 
 prevent obstructing the view of passing trains. 
 
 1717. Throwing Sivitches. — Foremen should not 
 throw switches for trivial reasons. An empty hand car or 
 push car should always be carried from one track to another, 
 and, if carrying a light load, it can be handled without 
 throwing a switch. Most foremen carry a switch key, but 
 it should be used with proper discretion and never -in the 
 absence of the foreman. The person tending to the switch 
 should always retnain by it until it is set for the main track 
 and locked. Any foreman who makes a practice of throw- 
 ing switches where it is unnecessary should be discharged 
 at once. 
 
 1718. Care of Tools. — The section foreman is re- 
 sponsible to the railway company for all tools and other 
 supplies issued to him. The systematic use and care of 
 tools will greatly increase their efficiency and prolong their 
 
1154 TRACK WORK. 
 
 service, and it is evident that the foreman can not better 
 serve his company than by instructing his men in the proper 
 handling and care of tools. 
 
 Hand cars and push cars should be oiled regularly, the 
 axle and other boxes kept tight, and the cars kept always 
 ready for service. Hand cars should not be used to carry 
 steel except in emergencies, and then only a light load 
 should be taken, the rails being placed on both sides of the 
 car so as to balance. Both rails and ties should be trans- 
 ported on the push car. 
 
 Shovels figure largely in the tool account chargeable to 
 track repairs. On most sections this account is unneces- 
 sarily large, owing to the many improper uses to which the 
 shovel is put. A shovel should never be used to hold up 
 the end of a tie for spiking, -nor driven into a tie in place of 
 a pick to pull the tie into its trench in the track. As soon 
 as the edge begins to turn, it should be straightened, and, 
 if necessary, trimmed with a cold chisel. Proper care will 
 often double the life of a shovel. 
 
 Claw bars should never be used to pry up the track, and, 
 above all, in frosty weather, as the claws are then easily 
 broken, and are always difficult to repair. 
 
 1719. Care of Material. — A sure test of a good fore- 
 man is his care for all material placed in his charge. When- 
 ever track repairs of any kind are made, all loose material 
 of every kind should be collected, and, with the exception 
 of rails, should be carried to the section house, where it 
 may be sorted. Much old material, such as splice bolts 
 and spikes, rtiay, with a little straightening, be made to 
 serve a second time and be as serviceable as new mate- 
 rial. All old iron should be piled in places convenient to 
 the track, whence it may be shipped at the direction of the 
 roadmaster. 
 
 1720. Care of Station Grounds. — It is particularly 
 to the section foreman's interest to keep the station grounds 
 in perfect order. By a little thought and planning, he can 
 find time to grade the approaches to the station, plant a few 
 
TRACK WORK. 1155 
 
 shade trees, and do some sodding where it will tell. This 
 work must not be done at the expense of regular track work, 
 but a spare hour is often available, and the results, if the 
 time has been wisely expended, amply pay for the outlay. 
 Neat station grounds encourage travel, and are sure to win 
 the approbation of superior officers. 
 
 1721. Work-Train Service. — The foreman in 
 charge of a work train should make it his business to keep 
 his men at work whenever the train is delayed. There is 
 always plenty of work to do along the track at any point, 
 and by proper forethought and planning, these unavoidable 
 delays may be turned to full account. 
 
 Every work train should be in charge of a thorough track- 
 man, who should, in addition, be thoroughly competent to 
 run a train. 
 
 Work-train conductors and foremen in pharge of gravel 
 pits or of steam-shovel outfits should receive their orders 
 from and be responsible to the roadmaster of the division 
 upon which they are working. They should send in a daily 
 report to the roadmaster, and every evening after quitting 
 send in to the dispatcher a lay-tip report, stating where they 
 will work the following day. Work trains should always lay 
 up at a telegraph station. 
 
 Conductors in charge of work trains should see that all 
 axle boxes are properly packed and oiled, and any accidents 
 to cars or any part of the outfit should be promptly reported 
 to the roadmaster. 
 
 1722. T.rack Inspection. — There shou4d be a well- 
 organized system of track inspection on every railroad. The 
 amount of inspection should be in proportion to the excel- 
 lence of the track and the amount of traffic. Whatever the 
 amount of traffic, the entire section should be inspected each 
 day. In ordinary weather this work may be entrusted to a 
 careful section hand, but in stormy weather the sect ion fore- 
 man should give his entire section a careful inspection. It 
 is best that the track inspection, especially at the more dan- 
 gerous points, should be made before the passage of express 
 
1166 TRACK WORK. 
 
 trains. On double-track roads where the traffic is heavy, 
 track inspection is performed by regular track walkers. They 
 should always carry a track wrench, to tighten loose bolts, 
 and a flag and torpedoes for signals. During the winter 
 months, when the ground is frozen solid, the frost, which 
 hinders many kinds of general track work, is constantly 
 heaving the track out of line and surface, and greatly in- 
 creasing the danger of accident. A rule requiring the sec- 
 tion foreman to see his entire section daily should be strictly 
 enforced. During extremely cold weather the track requires 
 constant watching. ' During heavy storms, it is a good plan 
 to go by train against the storm, to the end of the section, 
 and inspect the track while returning on foot. Two or 
 three inspections in a day are none too many for severe, 
 stormy weather. 
 
 1 723. Methods of Work. — Every foreman should be 
 on the alert to learn new and approved methods of 
 work. By careful thought he may devise time and 
 labor-saving methods himself. Work slowly done is not 
 necessarily well done. In fact, expedition is an adjunct to 
 excellence, as no man can do work rapidly without giving it 
 his full attention, and any work, however simple, that has 
 heart put into it, will show it by superior excellence. 
 
 1724. Discipline. — A foreman to succeed must be 
 superior to his men both in knowledge and in force of will. 
 Abusive and profane language will soon demoralize men, 
 robbing them of all respect for their foreman and for them- 
 selves. Patience in teaching men their duties. and habitual 
 fair treatment will make an enviable reputation for any fore- 
 man. He will always receive prompt and efficient service 
 from his men, can always count on a full gang, and can 
 readily increase his force for an emergency. Railroad com- 
 panies always prefer to fill their important offices with men 
 who have been tried and promoted in their own service. The 
 young foreman may be sure that competence and faithful- 
 ness will not go unrecognized or unrewarded. He should 
 take advantage of every opportunity to increase his know- 
 
TRACK WORK. 
 
 1157 
 
 ledge of his craft, and do all in his power to make it rank as 
 a profession. 
 
 1725. Section Records. — Every section foreman 
 should keep a record of everything connected with the track 
 under his charge. This record should be neatly and clearly 
 arranged, and should contain all information which may be 
 used as a basis for estimates, for the location of structures, 
 or for the distribution of material. 
 
 The following will suggest suitable forms for such a record : 
 
 SECTION NO. 8- 
 
 Length of section 6 miles 1,500 feet 
 
 Length of east side track 1,200 feet 
 
 Length of station side track 1,600 feet 
 
 Length of west side track 1,400 feet. 
 
 Bridge Number. 
 
 Number of 
 Bents. 
 
 Length of Span. 
 
 Distance from 
 Station. 
 
 60 
 61 
 62 
 
 4 
 
 7 
 Iron 
 
 48 feet 
 84 feet 
 90 feet 
 
 3 miles 
 3f miles 
 4^ miles 
 
 Culvert Number. 
 
 Box Culvert. 
 
 Iron Pipe. 
 
 Distance from 
 Station. 
 
 176 
 
 177 
 
 1 
 
 1 
 
 1\ miles 
 2 miles 
 
 178 
 
 1 
 
 54- miles 
 
 
 
 
 Cuts, Length 
 in feet. 
 
 Height above 
 Rail. 
 
 Material. 
 
 Distance from 
 Station. 
 
 One, 425 
 One, 650 
 One, 500 
 
 6 feet 
 4 feet 
 8 feet 
 
 Clay 
 
 Gravel 
 
 Rock 
 
 2^ miles 
 3|- miles 
 5 miles 
 
 Steel Rails, 
 Amount. 
 
 When Laid. 
 
 Brand. 
 
 Extends from 
 Station. 
 
 3 mi. 1,000 ft. 
 3 mi. 500 ft. 
 
 1884 
 
 1889 
 
 E. Thompson 
 L. L & S. Co. 
 
 North 
 To end of Sec. 
 
1158 TRACK WORK. 
 
 1726. Average Day's W^ork for One Man. — The 
 
 following is a list of the various kind of labor connected with 
 track work, and gives the amount of each which a good man 
 can perform in one day. This will serve to show the relation 
 existing between the labor of one man and a gang of men at 
 any of the different kinds of work specified: 
 
 One man can 
 
 Place on a grade one-eighth of a mile of ties. 
 
 Spike one-tenth of a mile of track laid on soft ties. 
 
 Spike one-fourteenth of a mile of track laid on hard ties. 
 
 Splice and bolt one-sixth of a mile of track. 
 
 Clean with a shovel one-eighth of a mile of average weeds. 
 
 Unload 10 cars of gravel. 
 
 Unload 8 cars of dirt. 
 
 Load upon cars, 18 to 24 cubic yards of gravel. 
 
 Load upon cars, 20 to 25 cubic yards of dirt. 
 
 Load coal into buckets for engines, 15 to 20 tons. 
 
 Unload coal into sheds, 25 to 30 tons. 
 
 Put into dirt ballast track, 20 new ties. 
 
 Put into gravel ballast track, 15 new ties. 
 
 Put into stone ballast track, 8 to 10 new ties. 
 
 Do labor equal to ballasting 60 feet of gravel ballasted 
 track. 
 
 Do labor equal to ballasting 35 feet of stone ballasted 
 track. 
 
 Chop 2 cords of 4 ft. wood. 
 
 Make 15 to 25 hard wood ties. 
 
 Make 35 to 40 soft wood ties. 
 
 Sixty men can lay one mile of track in a day. 
 
 1 727. Tables of Material Required for One Mile 
 of Track : 
 
TRACK WORK. 
 
 1159 
 
 TABLE 36. 
 
 TONS OF RAILS REQUIRED PER MILE OF TRACK. 
 
 Weight 
 
 Tons (2,240 Lb.) 
 
 Weight 
 
 Tons (2 
 
 ,240 Lb.) 
 
 per Yard. 
 
 per Mile. 
 
 per Yard. 
 
 per 
 
 Mile. 
 
 Pounds. 
 
 Tons. Pounds. 
 
 Pounds. 
 
 Tons. 
 
 Pounds. 
 
 8 
 
 12 1,280 
 
 56 
 
 88 
 
 .... 
 
 12 
 
 18 1,920 
 
 57 
 
 89 
 
 1,280 
 
 16 
 
 25 320 
 
 60 
 
 94 
 
 640 
 
 25 
 
 39 640 
 
 62 
 
 97 
 
 960 
 
 28 
 
 44 
 
 64 
 
 100 
 
 1,280 
 
 30 
 
 47 320 
 
 65 
 
 102 
 
 320 
 
 35 
 
 55 
 
 68 
 
 106 
 
 1,920 
 
 40 
 
 62 1,920 
 
 70 
 
 110 
 
 .... 
 
 45 
 
 70 1,600 
 
 72 
 
 113 
 
 320 
 
 48 
 
 75 960 
 
 76 
 
 119 
 
 960 
 
 50 
 
 78 1,280 
 
 80 
 
 125 
 
 1,600 
 
 52 
 
 81 1,600 
 
 
 
 
 To find the number of gross 
 one mile of track: 
 
 Rule. — Divide the weight per 
 quotient by 11. 
 
 Example.— For 70 lb. rail. 70 h- 7 = 10; 10 x 11 = 110 tons. 
 
 tons of rails required for 
 yard by 7 and multiply the 
 
 TABLE 37. 
 
 NUMBER OF CROSS-TIES PER MILE. 
 
 Distance, Center 
 to Center. 
 
 Number of Ties. 
 
 \\ feet 
 
 3,520 
 
 If feet 
 
 3,017 
 
 2 feet 
 
 2,640 
 
 2i feet ' 
 
 2,348 
 
 2^ feet 
 
 2,113 
 
 2| feet 
 
 1,921 
 
 3 feet 
 
 1.761 
 
1160 
 
 TRACK WORK. 
 
 TABLE 38. 
 
 NUMBER OP RAILS, SPLICBS, AND BOLTS PER MILE OP 
 
 TRACK. 
 
 Length of Rail. 
 
 No. of Rails 
 per Mile. 
 
 No. of Splices. 
 
 No. of Bolts, 
 
 4 to Each 
 
 Joint. 
 
 No. of Bolts, 
 
 6 to Each 
 
 Joint. 
 
 18 feet 
 
 584 
 
 1,168 
 
 2,336 
 
 3,504 
 
 20 feet 
 
 528 
 
 1,056 
 
 2,112 
 
 3,168 
 
 21 feet 
 
 503 
 
 1,006 
 
 2,012 
 
 3,018 
 
 22 feet 
 
 480 
 
 960 
 
 1,920 
 
 2,880 
 
 24 feet 
 
 440 
 
 880 
 
 1,760 
 
 2,640 
 
 25 feet . 
 
 422 
 
 844 
 
 1,688 
 
 2,532 
 
 26 feet 
 
 406 
 
 812 
 
 1,624 
 
 2,436 
 
 27 feet 
 
 391 
 
 782 
 
 1,564 
 
 2,346 
 
 28 feet 
 
 377 
 
 754 
 
 1,508 
 
 2,262 
 
 30 feet 
 
 352 
 
 704 
 
 1,408 
 
 2,112 
 
 TABLE 39. 
 
 RAILROAD SPIKES PER MILE OP TRACK. 
 
 Size Measured 
 Under Head. 
 
 Average Num- 
 ber per Keg 
 of 200 lb. 
 
 Ties 2 Ft. Between 
 
 Centers, 
 4 Spikes to a Tie. 
 
 Rails Used, 
 
 Pounds 
 
 per Yard. 
 
 
 
 Pounds. 
 
 Kegs. 
 
 
 H X tV 
 
 375 
 
 5,870 
 
 2H 
 
 45 to 70 
 
 5 Xt\ 
 
 400 
 
 5,170 
 
 26 
 
 40 to 56 
 
 5 X i 
 
 450 
 
 4,660 
 
 23i 
 
 35 to 40 
 
 4iX i 
 
 530 
 
 3,960 
 
 20 
 
 28 to 35 
 
 4 X i 
 
 600 
 
 3,520 
 
 17f 
 
 24 to 35 
 
 Hx^ 
 
 4 XtV 
 
 680 
 720 
 
 3,110 
 2,910 
 
 15^ 
 141 
 
 i 20 to 30 
 
 Hx^ 
 
 4 X f 
 
 900 
 1,000 
 
 2,350 
 
 2,090 
 
 11 
 10^ 
 
 [ 16 to 25 
 
 Hx 1 
 
 3 X 1 
 
 1,190 
 1,240 
 
 1,780 
 1,710 
 
 9 
 8i 
 
 [• 16 to 20 
 
 nx i 
 
 1,342 
 
 1,575 
 
 n 
 
 12 to 16 
 
TRACK WORK. 
 
 IIGI 
 
 TABLE 40. 
 
 NUMBER OF TRACK BOLTS IN A KEG OF 200 LB- 
 
 Rails Used. 
 
 Bolts. 
 
 Size Nuts. 
 
 Bolts in Keg. 
 
 Kegs per Mile. 
 
 40 to 70 
 
 |X4i 
 
 Usq. 
 
 195 
 
 7.3 
 
 40 to 70 
 
 f X 4 
 
 Hsq. 
 
 200 
 
 7.1 
 
 40 to 70 
 
 |X3| 
 
 lisq. 
 
 208 
 
 7.0 
 
 40 to 70 
 
 f X3i 
 
 Hsq. 
 
 216 
 
 (}.6 
 
 25 to 40 
 
 f X4 
 
 Usq. 
 
 305 
 
 4.7 
 
 25 to 40 
 
 f X3i 
 
 lisq. 
 
 329 
 
 4.3 
 
 25 to 40 
 
 iXU 
 
 1 sq. 
 
 . 576 
 
 2.6 
 
 18 to 20 
 
 i X 2i 
 
 1 sq. 
 
 654 
 
 3.3 
 
 40 to 70 
 
 1 X 3^ 
 
 If hex. 
 
 170 
 
 8.3 
 
 40 to 70 
 
 |X 3f 
 
 If hex. 
 
 237 
 
 6.0 
 
 40 to 70 
 
 f X3i 
 
 1^ hex. 
 
 228 
 
 6.3 
 
 40 to 70 
 
 f X 4 
 
 If hex. 
 
 220 
 
 6.5 
 
 25 to 40 
 
 tx3^ 
 
 1 hex. 
 
 415 
 
 3.4 
 
RAILROAD STRUCTURES. 
 
 WOODEN TRESTLES. 
 
 1 728. Extent of Trestling. — The amount of wooden 
 trestling in use on American roads is very large, and covers 
 a wide range in both material and design. As the period of 
 construction is always a severe test of the financial strength 
 of a railroad com'pany, it has been the almost universal 
 policy in this country to use temporary structures of moder- 
 ate cost, wherever possible, and to defer the erection of 
 permanent structures until traffic is on a paying basis and 
 finances are easy. Hence it follows that of the 2,500 miles 
 of trestle now in use on American roads, fully one-quarter will 
 be replaced by embankment. Of the remaining 1,900 miles, 
 at least 800 miles will be maintained in wood. It is, there- 
 fore, a matter of great importance that these structures, 
 whether temporary or permanent, should be well planned 
 and constructed in order that they may best meet the 
 requirements of safety and economy. 
 
 1729. Average Life of a Wooden Trestle. — The 
 
 average life of a wooden trestle is taken at 8 years, and 
 the question of renewal will depend upon the compara- 
 tive cost of an embankment with the requisite amount of 
 masonry for watercourses, or for the rebuilding of the 
 wooden structure at intervals of 8 years. Trestles which are 
 to be replaced by embankments may properly differ consider- 
 ably in design from those which are to be periodically re- 
 newed. Temporary trestles should possess the qualities of 
 simplicity and strength alone, while those which are to be 
 
1164 
 
 RAILROAD STRUCTURES. 
 
 
 
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RAILROAD STRUCTURES. 1165 
 
 maintained in wood should be so designed that they may be 
 renewed without any interruption of traffic. In either case, 
 the use of any other than the best available material is to be 
 condemned as poor economy. The cost of the construction 
 of a trestle is a considerable percentage of its total cost, and 
 is but slightly affected by the character of the materials com- 
 posing it, and, hence, the small saving effected by the use 
 of cheaper materials is neutralized by the shortened life of 
 the structure and its general lack of excellence 
 
 A good wooden structure is preferable to a cheap iron one, 
 though the impression commonly prevails that an iron 
 structure must necessarily be strong and efficient. Many 
 new lines traverse sections where timber is abundant and 
 cheap, bringing the cost of wooden structures within safe 
 reach of the railroad company, whereas costly structures of 
 iron or heavy fills might have wrecked the company and the 
 enterprise. 
 
 1 730. Comparative Cost of Trestles and Em- 
 bankments. — The height at which it becomes more eco- 
 nomical to substitute trestling for embankment varies 
 widely, depending upon the locality, the cost of timber, 
 labor, and the character of material available for making the 
 fill. There are, of course, many situations, such as deep 
 swamps or waterways, where an embankment is out of the 
 question. It then becomes a choice between wooden and 
 iron structures. 
 
 The cost of an embankment increases in a vastly greater 
 ratio than its height, as will be seen from Table 41. The 
 cost of trestling, on the other hand, does not increase nearly 
 as rapidly as its height, especially for heights under 50 feet. 
 The cost of pile and framed trestles for heights from 5 to 
 45 feet, inclusive, is given in Table 42. 
 
 1731. Mathematical Formulas of Slight Use in 
 Trestle Designing. — Few engineers employ mathematical 
 formulas in designing trestles. The strength and properties 
 of timber vary with each separate piece, and in proportioning 
 
1166 
 
 RAILROAD STRUCTURES. 
 
 the parts of a trestle it is far safer to rely upon one's own 
 judgment, if supported by large experience, or to follow 
 the approved examples of other men, than to rely upon any 
 set of mathematical formulas. American railroads show a 
 wide range in trestle design, each important road having 
 a set of standard designs which may differ more or less from 
 those employed on other lines. The designs given in this 
 paper are copies of some of the best standards in use on 
 American roads, and cover a range wide enough to meet the 
 requirements of all ordinary situations. 
 
 TABLE 42. 
 
 Cost of Pile and Framed Trestles, complete, including 
 Floor Systems for Different Heights in Sections of 100 
 feet. 
 
 Height 
 
 Pile. 
 
 Framed. 
 
 in Feet. 
 
 $30 
 
 $35 
 
 $40 
 
 $30 
 
 $35 
 
 $40 
 
 5 
 
 1546 
 
 $605 
 
 $665 
 
 $453 
 
 $528 
 
 $604 
 
 10 
 
 611 
 
 674 
 
 738 
 
 555 
 
 647 
 
 740 
 
 15 
 
 678 
 
 742 
 
 806 
 
 634 
 
 739 
 
 844 
 
 20 
 
 746 
 
 811 
 
 877 
 
 711 
 
 829 
 
 947 
 
 25 
 
 918 
 
 1,001 
 
 1,084 
 
 966 
 
 1,126 
 
 1,286 
 
 30 
 
 986 
 
 1,070 
 
 1,154 
 
 1,042 
 
 1,215 
 
 1,389 
 
 35 
 
 1,160 
 
 1,263 
 
 1,366 
 
 1,228 
 
 1,432 
 
 1,636 
 
 40 
 
 1,227 
 
 1,332 
 
 1,444 
 
 1,303 
 
 1,520 
 
 1,736 
 
 45 
 
 
 
 
 1,372 
 
 1,602 
 
 1 832 
 
 
 
 
 
 
 1 732. Classes of Trestles. — Wooden trestles are 
 
 divided into two general classes, viz., pile trestles, in which 
 the bents consist of piles united by a cap, and framed 
 trestles, in which the bents consist of squared timbers 
 framed together. Pile trestles are rarely used for heights 
 exceeding 30 feet. Framed trestles may be of almost any 
 
RAILROAD STRUCTURES. 
 
 1167 
 
 height, though special designs are required for those ex- 
 ceeding a height of 30 feet. 
 
 Fig. 548. 
 
 1733. Technical Terms and IVames. — In order 
 that the student may understand the various parts com- 
 posing a trestle, the following technical terms and names are 
 
 V 0° 
 
 
 °o 4 
 
 n m 
 
 V 
 
 
 *. 
 
 
 8^ 
 
 
 Fig. 549. 
 
 given, the number accompanying each term corresponding 
 to the parts given in Figs. 548 and 549: 
 
1168 
 
 RAILROAD STRUCTURES. 
 
 Bent, Framed, 1. 
 Bent, Pile, 2. 
 Cap, 3. 
 Cross-tie, 4. 
 Dapping, 5. 
 
 Gaining, see Dapping, 5. 
 Guard-rail, 0. 
 Jack-stringer, 7. 
 Longitudinal Brace, 8. 
 Mortise, 9. 
 Mud-sill, 10. 
 
 Notching, Gaining, Dap- 
 ping, 5. 
 Packing-block, 11. 
 
 Packing-bolts, 12. 
 
 Piles, Batter, Inclined, 
 Brace, 13. 
 Vertical, Plumb, Upright, 
 14. 
 
 Posts, Vertical, Plumb, Up- 
 right, 15. 
 Batter, Inclined, 16. 
 
 Sill, 17. 
 
 Stringer, 18. 
 
 Sway-brace, 19. 
 
 Tenon, 20. 
 
 Waling-strip, see Longi- 
 tudinal Brace, 8. 
 
 1734. Pile Bents. — As the subject of pile driving 
 
 was fully discussed in the section on Railroad Construction, 
 no reference will be made in this section to the theory of pile 
 driving. Where the line traverses low, marshy ground, 
 either constantly overflowed or subject to occasional over- 
 flow, and where the height of the rails above the surface of 
 the ground does not exceed 30 feet, a pile bent is generally 
 adopted. When pile bents are used for greater heights than 
 30 feet, only the tops of the piles penetrate the ground, and 
 though they may reach a substantial bottom, the bent is 
 essentially weak, owing to the small diameter of the pile 
 and the small proportion of heart timber at the top of the 
 tree. It is the heart timber alone which can long resist 
 decay, and at the surface of the ground, where the timber is 
 alternately wet and dry, decay sets in as soon as the struc- 
 ture is erected, and in a few years, at best, the piles must be 
 renewed, though the remainder of the trestle may be in a 
 comparatively sound condition. 
 
 Piles should be cut from live, straight, thrifty trees, free 
 from dead or loose knots, wind shakes, and all descriptions 
 of decay, and be stripped of bark. They should have a butt 
 diameter of from 12 to 15 inches, and a top diameter of from 
 7 to 10 inches inside the bark. Squared piles are used in a 
 
RAILROAD STRUCTURES. 
 
 1169 
 
 limited way, and when so used they should measure 12 inches 
 square at the butt, and not show more than 2 inches of sap 
 wood on the corners. It is the custom on some lines to 
 paint the pile for a short distance above and below the 
 ground line with hot tar, thus tending to retard decay. 
 
 Timber suitable for piles may be found in most sections 
 of the United States. The different varieties of timber 
 commonly used for piling are named in the following list in 
 the order of their excellence: 
 
 Red Cedar, 
 Black Cypress, 
 Pitch Pine, 
 Yellow Pine 
 (long-leaf), 
 
 White Pine, 
 Redwood, 
 Elm, 
 Spruce, 
 
 White Oak, 
 Post Oak, 
 Tamarack, 
 Hemlock. 
 
 The arrangement of the piling forming the bent varies 
 considerably with different constructors in the matter of 
 
 I- 5*0 
 
 12-0 
 
 4-0 
 
 s 
 
 14-0' 
 
 33r 
 
 4-6 
 
 fh 
 
 ! i i I I i 
 
 Figs. 550 and 551. 
 
 Figs. 552 and 553. 
 
 spacing the piles, though the general arrangement is the 
 same. 
 
 For a height of bent not exceeding 5 feet, and where the 
 
1170 RAILROAD STRUCTURES. 
 
 road is to carry only a moderate traffic, a three-pile bent is 
 generally adopted, one pile being placed directly upon the 
 center line and the others spaced from 3 feet 6 inches to 
 
 5 feet out, the piles being driven vertically. (Fig. 550.) 
 For trunk lines, however, whatever the height, all bents 
 should contain four piles. 
 
 For heights of from 5 to 15 feet, each bent should contain 
 four piles driven vertically. The inner piles may be spaced 
 from 4 to 5 feet and the outer ones about 11 feet from center 
 to center. (Fig. 551.) Pile bents of this height will not 
 require sway bracing, provided the penetration amounts to 
 
 6 or 8 feet in firm earth. For heights exceeding 15 feet, it 
 is well to batter the outside piles, as shown in Fig. 552. By 
 this means the width of the base is considerably increased, 
 giving in appearance, as well as in fact, greater stability to 
 the structure. Piles are battered from 2 to 4 inches to the 
 foot, 3 inches being commonly adopted. 
 
 On Western roads, vertical pile bents of heights of 20 
 feet and over are frequently seen, but they give the im- 
 pression of a lack of stability, which the battered piles at 
 once remove. Where the diameter of the pile at the cut-off 
 point exceeds the width of the cap, the part of the pile 
 which projects should be adzed off at an angle of 45°, 
 (Fig. 553.) 
 
 1 735. Splicing Piles. — When the material into which 
 the piles are driven is soft ground, extending to a great 
 depth, it may be necessary to splice the piles in order to 
 reach a firm foundation. In splicing, the piles are placed 
 end to end, and united either by dowels, bands, or scarf- 
 ings. Three different forms of splices are shown in Figs. 
 554, 555, and 55G. Those shown in Figs. 554 and 555 are 
 commonly adopted. The first pile is driven until its top is 
 within easy reach from the surface of the ground. It is 
 then cut off and trimmed up for splicing, and the second 
 pile placed upon and fastened to it. When the ground is 
 in a partially fluid state, the pile already driven will have 
 but little stiffness, so that if either of the splices shown in 
 
RAILROAD STRUCTURES. 
 
 1171 
 
 Fig. 554. 
 
 Fig. 555. 
 
 Fig. 556. 
 
 Figs. 554 and 555 is used, the piles are liable to 
 cant in driving and the splice to give way. In 
 such cases it is better to 
 strengthen the splice with 
 scarfings, say 3 inches by 3 
 inches by 8 or 10 feet in 
 length, spiked to the piles as 
 shown in Fig. 556. This 
 splice was used in the false 
 work for the erection of the 
 Poughkeepsie bridge, and 
 proved very efficient. When 
 the band splice (Fig. 555) is used, some de- 
 vice must be used to keep the band in place, 
 else, after a few blows of the hammer, it will 
 be found wholly on one pile or the other. Rail- 
 road spikes driven above and below the band, as 
 shown in Fig. 555, will prevent this movement. 
 
 1736. Determining the Length of 
 Piles Required. — If the bridge is to be a 
 long one, requiring a large number of piles, it 
 'is important that the approximate lengths of the 
 piles required and the number of each should be 
 known before ordering the material. The fol- 
 lowing method, adopted by the Northern Pacific 
 Railroad Company for their bridge over the St. 
 Louis river, at Duluth, proved very satisfactory. 
 Test piles were driven every 300 feet along the 
 center line, and where any considerable variation 
 in penetration was noticed, an intermediate pile 
 was driven. The piles were driven from a scow, 
 the space between the piles being regulated by a 
 rope attached to the last pile driven. After the 
 piles were all driven, their exact location was de- 
 termined by triangulation. A careful record was 
 kept of the driving of each test pile, the notes 
 being kept in the following form; 
 
1172 
 
 RAILROAD STRUCTURES. 
 
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RAILROAD STRUCTURES. 
 
 1173 
 
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 1737. Record Ta- 
 bles of Progress and 
 Cost of Pile Driving. — 
 
 The penetration of the 
 pile was not measured 
 until the rate of sinking 
 indicated firm bottom, af- 
 ter which the penetration 
 was measured for the last 
 twenty or thirty blows, 
 in sets of ten consecutive 
 blows. In all cases the 
 piles were driven until the 
 requirements of the speci- 
 fications were met, viz., a 
 20-foot fall of a 2,000 lb. 
 hammer to cause a pene- 
 tration not to exceed 1 
 inch. The notes relatin-g 
 to the size and driving 
 of the pile were taken by 
 the inspector at the time, 
 the elevations by the en- 
 gineer afterwards. A 
 profile was then made up 
 from these notes, and the 
 piles ordered according 
 to the lengths measured 
 upon this profile. This 
 scheme for estimating 
 piling from actual tests 
 proved a complete suc- 
 cess, there being few dis- 
 crepancies between the 
 material in place and that 
 ordered. The waste of ma- 
 terial was consequently 
 reduced to a minimum. 
 
1174 
 
 RAILROAD STRUCTURES. 
 
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RAILROAD STRUCTURES. 
 
 117^ 
 
 A permanent record of each structure should be made in 
 detail during construction for the future use of the main- 
 tenancc-of-way department. An excellent form of such a 
 record, and the one used on the above work, is given here. . 
 
 This gives actual cost of driving after the piles were 
 delivered at the pile driver, but it is a very low average of 
 cost, the work being done by the firm of Winston Bros., of 
 Minneapolis, noted for their energy and excellence of plant 
 equipment. 
 
 In making approximate estimates of cost of piling and 
 trestles, when exact data are not available, the preceding 
 table of cost will serve as a safe guide, as it is based on 
 actual contract prices. 
 
 1 738. Capping Piles. — When a floating pile driver is 
 used, the sawing off and capping of the piles may follow the 
 
 Fig. 557. 
 
 driving, at the convenience of the contractor, though it is 
 better to follow the driving closely with the caps and 
 stringers. When a land driver is used, each bent must be 
 cut off and capped and timbers laid before the driver can 
 advance to the next bent. As soon as a bent of piles is 
 ready for cutting off, the height of the top of pile is given 
 with an instrument, and a narrow, straight-edged strip of 
 board (ordinary roofing lath serves well) is nailed on each 
 side of the bent, with its top edge at the proper height for 
 cutting off. (Fig. 557.) The cutting off is best done with a 
 cross-cut saw worked by two men. If the piles are tenoned 
 to the caps, the cutting necessary to form the tenon is done 
 with the cross-cut saw. 
 
117G 
 
 RAILROAD STRUCTURES. 
 
 1 739. Caps may be fastened to the piles in three differ- 
 ent ways, viz. : By mortise and tenon, by drift bolts, or by 
 dowels. For solid caps, a tenon 3 inches thick, 8 inches 
 wide, and 5 inches long is a good size (see Fig. 558). The 
 
 top edges of the tenon should be chamfered 
 and the mortise and tenon made so as to fit 
 snugly. The parts are held together by 
 means of wooden pins, called treenails. Tree- 
 nails are from 1 mch to 1^ inches in diameter, 
 and slightly tapering (see Fig. 558). They 
 should be made of hard wood, oak or locust 
 to be preferred. The hole made in the cap 
 to receive the pin should be spaced a little 
 further from the base of the cap than the hole 
 in the tenon from the tenon shoulder, so that 
 in driving the pin, the parts will be drawn together. Iron 
 bolts or pins should never be used in place of wooden pins. 
 Instead of crowding or drawing the parts together, the iron 
 punches or cuts away any wood which lies in its path, 
 merely increasing the size of the hole. 
 
 1740. When drift bolts or dowels are used, the piles 
 are cut off level, and holes are bored in both cap and pile 
 to receive the drift bolt or dowel. Sometimes two drift bolts 
 or dowels are used at each pile, but commonly only one. 
 
 Fig. 559 Fig. 560. Fig. 561. 
 
 which is amply sufficient. A hole is first bored through the 
 cap into the pile head to receive the drift bolt, which should 
 be somewhat larger than the hole, so that in driving, every 
 cavity in the hole may be completely filled (see Fig. 559). 
 
RAILROAD STRUCTURES. 1177 
 
 1741. Dowels are of shorter length than drift bolts 
 and extend only about half way through the caps (see 
 Fig. 5G0). 
 
 Another method of fastening caps to piles, and one which 
 is rapidly growing in favor, is by means of split caps, shown 
 in Fig. 561, in which the cap, instead of being a single piece 
 of timber, consists of two pieces, each half the size of the 
 single piece. 
 
 For example, instead of using for the cap a single stick 
 of timber 12 inches by 12 inches, as shown in Figs. 559 and 
 560, we substitute two pieces a and b (Fig. 561), each 
 6 inches by 12 inches. A tenon r, 3 inches wide and extend- 
 ing the full width of the pile, is formed at its top, and a cap 
 is placed on each shoulder against the tenon. A f -inch bolt 
 ^ is passed through the caps and tenon, holding them firmly 
 in place. The caps should not be notched, and the piles 
 should be sawed off smooth and level, so as to afford a good 
 bearing for the caps. Some of the advantages claimed for' 
 split caps are the following: 
 
 1st. On account of smaller size, better timber can be 
 obtained at less cost. 
 
 2d. Repairs can be made with ease and great economy of 
 time and labor. 
 
 3d. Traffic need not be interrupted nor endangered while 
 repairs are being made. 
 
 4th. The caps may be replaced without cutting or 
 injuring any other part of the structure. 
 
 oth. Economy in material, because it is not necessary to 
 replace the whole cap unless both sticks are decayed, but 
 only that part which is no longer in a serviceable condition. 
 
 FRAMED BENTS. 
 
 1742. Foundations. — Framed bents are composed 
 entirely of sawed timber, and are placed upon a foundation, 
 the objects of which are to ensure stability to the structure, 
 and, by raising it from the ground, to prolong its life. All 
 timber placed in direct contact with the ground partakes of 
 
1178 
 
 RAILROAD STRUCTURES. 
 
 all its changing conditions of drouth and moisture, which 
 soon induce decay. It is also desirable that the foundation 
 should be as little affected by changes of temperature and 
 moisture as possible. Among the various kinds of founda- 
 tions used for trestle bents are the following: masonry, pili\ 
 sub-sill, grillage, crib, solid rock, and loose rock. 
 
 1743. Masonry foundations are the best. They are 
 ordinarily composed of rubble masonry, laid either in lime 
 or cement mortar. The latter is recommended, as it is not 
 aflfected by moisture. 
 
 Suitable masonry foundations are shown in Figs. 502 and 
 563. In northern latitudes, trenches at least 12 inches in 
 depth should be excavated for these foundations, to prevent 
 
 their being heaved by hard freezing. In exposed localities, 
 where the freezing is more severe, it may be necessary to 
 excavate the foundation trenches to a depth of 2 feet. 
 
 It is bad policy to use irregularly shaped stone, especially 
 cobble stone, in building trestle foundations. The continual 
 jar caused by passing trains is liable to seriously injure ma- 
 sonry of an inferior quality. Dry rubble, if built of long 
 stones with horizontal beds, and well bonded, is much supe- 
 rior to mortar rubble of poor quality. The foundation walls 
 shown in Figs. 502 and 563 are supposed to be laid in foun- 
 dation pits 12 inches deep, and to extend 2 feet above the 
 surface of the ground. The ends of the wall should be 
 vertical, and the sides battered about 2 inches to the foot. 
 
 When pile foundations are employed for marshy ground 
 of not too great depth, it is a good plan to allow the piles to 
 extend far enough above the surface of the ground to form 
 a bent, which is capped and a framed bent placed on top of 
 
RAILROAD STRUCTURES. 
 
 lltO 
 
 it. Where the trestle crosses a waterway, it is good practice 
 to place a framed bent upon a pile foundation of such height 
 as to remain always under water. The decay due to alter- 
 nate wetting and drying is thus confined to the framed 
 portion, which can easily be renewed. 
 
 1744. Sub-sills, or mud-sills, are blocks of timber 
 placed under the main sills to raise them above the ground 
 and so prevent decay. Some recommend planks 3 or 4 inches 
 in thickness, but 12-inch by 12-inch timber is far better, 
 and the additional cost is trifling compared with the solidity 
 of foundation and security agamst decay. The sills and sub- 
 sills should be fastened together, to prevent the latter from 
 being displaced. As the strain is slight, G-inch cut spikes, 
 
 FIG. 564. 
 
 driven as shown at «, a, in Fig. 564, will serve for a 
 fastening. 
 
 1745. A grillage of timber may be employed as a 
 foundation when the trestle crosses a marsh extending to a 
 great depth, but covered by a layer of earth possessing con- 
 siderable supporting power. Such marshes are frequent 
 in Canada and the States bordering on Canada. The grill- 
 age may be constructed either of sawed or round timber, 
 according to which is the most available. The grillage shown 
 in Fig. 5G5 was employed on the Northern Adirondack Rail- 
 road in crossing a subterranean lake. The lake was covered 
 with earth to the depth of several feet and overgrown with 
 brush and timber, but was unsafe for an embankment. The 
 longest piles failed to reach bottom, and the grillage shown 
 in the figure was employed. Each bent was supported by 
 four logs or rangers laid lengthwise the bent, and cross-tied 
 
1180 
 
 RAILROAD STRUCTURES. 
 
 by short logs which were drift-bolted to the rangers. The 
 logs were notched at each intersection, as shown in the de- 
 tail at A. The tops of the cross logs were adzed at their 
 middle to a common level to receive the bent sills which 
 were drift-bolted to the grillage. By this means the weight 
 of the trestle and trainload was distributed over a consid- 
 erable area. Though the road has been in operation more 
 
 mEj 
 
 X4-0 — 
 
 iriKm 
 
 h 8-0 ■\ 
 
 Fig. 565. 
 
 than a dozen years, no considerable settlement has taken 
 place. 
 
 1 746. Cribs may be employed for foundations where 
 the ground is very sidling, or they may be used as a sub- 
 stitute for masonry foundations where the line crosses or 
 borders on streams with rapid currents. At such points 
 timber and cobble stones for ballast are often to be had for 
 the asking, when masonry would prove very expensive. 
 
 A crib suitable for such foundations is shown in Fig. 566. 
 
RAILROAD STRUCTURES. 
 
 1181 
 
 The crib is of pyramidal form and built entirely of round 
 timber, notched together as shown in Fig. 505. On side 
 hill ground, the surface is broken up into steps, as shown in 
 the figure. The logs are drift-bolted together at the joints, 
 and the enclosed spaces filled with stone. The crib should 
 be long enough at the top to contain the sills, after full 
 
 Fig. 566. 
 
 allowance has been made for the batter posts. This makes 
 a cheap and substantial foundation, and it can be easily 
 built in a swift current of water. 
 
 1 747. If the surface is solid rock, all that is neces- 
 sary in preparing a foundation is to smooth off a place for 
 each post to stand on. The readiest way to fasten each post 
 is by means of a dowel, which should reach 5 or 6 inches 
 into the rock and an equal distance into the post. In some 
 instances, holes are blasted into the surface rock, and the 
 posts stood in the holes. After the posts are fastened to- 
 gether, forming a bent, the vacant space about the foot of 
 each post is filled with rich cement mortar. When such 
 foundations are used, the system of bracing should be ample, 
 especially where the trestle is built on a side hill requiring 
 posts of much greater length on the lower than on the upper 
 side. 
 
 1748. Loose Rock. — Where masonry foundations 
 would prove too costly, satisfactory foundations may be 
 
1182 
 
 RAILROAD STRUCTURES. 
 
 made of loose rock. These are made by excavating a short 
 trench directly under each post, as shown in Fig. 5fi7. 
 
 Fig. 567. 
 
 These trenches are filled rounding full of broken stone, and 
 sub-sills placed upon them, forming the supports for the sills. 
 If water accumulates in the trenches, it may be drained olT 
 by digging shallow open ditches around the foundations and 
 leading them away to lower ground. This will at least save 
 the sub-sills from contact with water and so preserve them 
 from rapid decay. 
 
 1749. Drip Holes. — The tendency of water to ac- 
 cumulate in mortises hastens decay of the timbers. To 
 
 prevent this, every 
 
 \y/^ 
 
 mortise forming a re- 
 ceptacle for water 
 should be provided 
 with a drip hole | inch 
 in diameter, bored with 
 a downward inclina- 
 tion from the bottom 
 of the mortise to the 
 
 Fig. 669. 
 Fig. 568. 
 
 outside of the timber. Two methods of boring drip holes 
 are shown in Figs. 508 and 5G9. 
 
 There are usually four posts to a bent; two vertical, or 
 plumb, posts, and two inclined, or batter, posts. The stand- 
 ard dimensions of trestle posts are 12 inches by 12 inches, 
 though other dimensions are sometimes used. The plumb 
 
RAILROAD STRUCTURES. 
 TABLE 44. 
 
 1183 
 
 LENG 
 
 rTH 
 
 OF 
 
 BATTER 
 
 POSTS. 
 
 BATTER 
 
 3 IIV. PER 
 
 FOOT. 
 
 
 
 
 Length 
 
 of Stick. 
 
 
 
 
 
 Length 
 
 of Stick. 
 
 
 Distance 
 Between 
 
 
 
 
 
 Distflr*'"* 1 
 
 
 
 
 
 Shr 
 
 ul- 
 
 St 
 
 ck 
 
 With 
 
 Betw« 
 
 en 
 
 She 
 
 ul- 
 
 Stick 
 
 With 
 
 Cap. 
 
 ind 
 
 der to 
 
 with 
 
 Two 
 
 Cap and 1 
 
 der to 
 
 with 
 
 Two 
 
 Sil 
 
 I. 
 
 Shoul- 
 
 Square 
 
 6-in. 
 
 Sill 
 
 
 Shoul- 
 
 Square 
 
 5- 
 
 n. 
 
 
 
 der. 
 
 Ends. 
 
 Ten 
 
 ons. 
 
 
 
 der. 
 
 Ends. 
 
 Tenons. 
 
 ft. 
 
 in. 
 
 ft. 
 
 in. 
 
 ft. 
 
 in. 
 
 ft. 
 
 in. 
 
 ft. 
 
 in. 
 
 ft. 
 
 in. 
 
 ft. 
 
 in. 
 
 ft. 
 
 in. 
 
 3 
 
 
 
 3 
 
 1 
 
 3 
 
 4 
 
 4 
 
 2 
 
 23 
 
 
 23 
 
 Si 
 
 23 
 
 IH 
 
 24 
 
 9i 
 
 3 
 
 6 
 
 3 
 
 n 
 
 3 
 
 lOi 
 
 4 
 
 8i 
 
 23 
 
 6 
 
 24 
 
 2f 
 
 24 
 
 H 
 
 25 
 
 3i 
 
 4 
 
 
 4 
 
 n 
 
 4 
 
 4i 
 
 5 
 
 2i 
 
 24 
 
 
 24 
 
 8| 
 
 24 
 
 Hi 
 
 25 
 
 n 
 
 4 
 
 6 
 
 4 
 
 n 
 
 4 
 
 lOf 
 
 5 
 
 8f 
 
 24 
 
 6 
 
 25 
 
 3 
 
 25 
 
 6 
 
 26 
 
 4 
 
 5 
 
 
 5 
 
 n 
 
 5 
 
 H 
 
 6 
 
 n 
 
 25 
 
 
 25 
 
 H 
 
 26 
 
 Oir 
 
 26 
 
 lOi 
 
 5 
 
 6 
 
 5 
 
 8 
 
 5 
 
 11 
 
 6 
 
 9 
 
 25 
 
 6 
 
 26 
 
 m 
 
 26 
 
 H 
 
 27 
 
 4| 
 
 6 
 
 
 6 
 
 2i 
 
 6 
 
 5i 
 
 7 
 
 3i 
 
 26 
 
 
 26 
 
 n 
 
 27 
 
 Of 
 
 27 
 
 lOf 
 
 6 
 
 6 
 
 6 
 
 8f 
 
 6 
 
 llf 
 
 7 
 
 9f 
 
 26 
 
 6 
 
 27 
 
 3f 
 
 27 
 
 6f 
 
 28 
 
 4i 
 
 7 
 
 
 7 
 
 2i 
 
 7 
 
 H 
 
 8 
 
 H 
 
 27 
 
 
 27 
 
 10 
 
 28 
 
 1 
 
 28 
 
 11 
 
 7 
 
 6 
 
 7 
 
 81 
 
 7 
 
 llf 
 
 8 
 
 n 
 
 27 
 
 6 
 
 28 
 
 4i 
 
 28 
 
 n 
 
 29 
 
 H 
 
 8 
 
 
 8 
 
 3 
 
 8 
 
 6 
 
 9 
 
 4 
 
 28 
 
 
 28 
 
 10| 
 
 29 
 
 If 
 
 29 
 
 llf 
 
 8 
 
 6 
 
 8 
 
 9i 
 
 9 
 
 Oi 
 
 9 
 
 lOi 
 
 28 
 
 6 
 
 29 
 
 4i 
 
 29 
 
 7i 
 
 30 
 
 H 
 
 9 
 
 
 9 
 
 H 
 
 9 
 
 n 
 
 10 
 
 H 
 
 29 
 
 
 29 
 
 lOf 
 
 30 
 
 1* 
 
 30 
 
 llf 
 
 9 
 
 6 
 
 9 
 
 H 
 
 10 
 
 Oi 
 
 10 
 
 10^ 
 
 29 
 
 6 
 
 30 
 
 H 
 
 30 
 
 n 
 
 31 
 
 5i 
 
 10 
 
 
 10 
 
 3f 
 
 10 
 
 H 
 
 11 
 
 4f 
 
 30 
 
 
 30 
 
 11 
 
 31 
 
 2 
 
 32 
 
 
 
 10 
 
 6 
 
 10 
 
 H 
 
 11 
 
 Oi 
 
 11 
 
 10| 
 
 30 
 
 6 
 
 31 
 
 H 
 
 31 
 
 Si 
 
 32 
 
 H 
 
 11 
 
 
 11 
 
 4 
 
 11 
 
 7 
 
 12 
 
 5 
 
 31 
 
 
 31 
 
 m 
 
 32 
 
 ^ 
 
 33 
 
 Oi 
 
 11 
 
 6 
 
 11 
 
 m 
 
 12 
 
 u 
 
 12 
 
 Hi 
 
 31 
 
 6 
 
 32 
 
 H 
 
 32 
 
 8f 
 
 33 
 
 6f 
 
 12 
 
 
 12 
 
 ^ 
 
 12 
 
 n 
 
 13 
 
 H 
 
 32 
 
 
 32 
 
 m 
 
 33 
 
 2| 
 
 34 
 
 Oi 
 
 12 
 
 6 
 
 12 
 
 lOf 
 
 13 
 
 If 
 
 13 
 
 IH 
 
 32 
 
 6 
 
 33 
 
 6 
 
 33 
 
 9 
 
 34 
 
 7 
 
 13 
 
 
 13 
 
 4| 
 
 13 
 
 n 
 
 14 
 
 51 
 
 33 
 
 
 34 
 
 Oi 
 
 34 
 
 3i 
 
 35 
 
 li 
 
 13 
 
 6 
 
 13 
 
 11 
 
 14 
 
 2 
 
 15 
 
 
 33 
 
 6 
 
 34 
 
 6| 
 
 34 
 
 9f 
 
 35 
 
 n 
 
 14 
 
 
 14 
 
 H 
 
 14 
 
 8i 
 
 15 
 
 6i 
 
 34 
 
 
 35 
 
 Oi 
 
 35 
 
 3i 
 
 36 
 
 H 
 
 14 
 
 6 
 
 14 
 
 111 
 
 15 
 
 2| 
 
 16 
 
 Of 
 
 34 
 
 6 
 
 35 
 
 6f 
 
 35 
 
 9f 
 
 36 
 
 7f 
 
 15 
 
 
 15 
 
 U 1 15 
 
 8i 
 
 16 
 
 H 
 
 35 
 
 
 36 
 
 0| 
 
 36 
 
 3i 
 
 37 
 
 li 
 
 15 
 
 6 
 
 15 
 
 111 
 
 16 
 
 2i 
 
 17 
 
 Of 
 
 35 
 
 6 
 
 36 
 
 n 
 
 36 
 
 m 
 
 37 
 
 8i 
 
 16 
 
 
 16 
 
 H 
 
 16 
 
 8J 
 
 17 
 
 6i 
 
 36 
 
 
 37 
 
 n 
 
 37 
 
 H 
 
 38 
 
 2i 
 
 16 
 
 6 
 
 17 
 
 
 
 17 
 
 3 
 
 18 
 
 1 
 
 36 
 
 6 
 
 37 
 
 n 
 
 37 
 
 lOi 
 
 38 
 
 Si 
 
 17 
 
 
 17 
 
 H 
 
 17 
 
 H 
 
 18 
 
 n 
 
 37 
 
 
 38 
 
 If 
 
 38 
 
 4| 
 
 39 
 
 2f 
 
 17 
 
 6 
 
 18 
 
 Oi 
 
 18 
 
 3* 
 
 19 
 
 n 
 
 37 
 
 6 
 
 38 
 
 n 
 
 38 
 
 lOi 
 
 39 
 
 8i 
 
 18 
 
 
 18 
 
 6| 
 
 18 
 
 H 
 
 19 
 
 n 
 
 38 
 
 
 39 
 
 2 
 
 39 
 
 5 
 
 40 
 
 3 
 
 18 
 
 6 
 
 19 
 
 Oi 
 
 19 
 
 H 
 
 20 
 
 n 
 
 38 
 
 6 
 
 39 
 
 Si 
 
 39 
 
 Hi 
 
 40 
 
 9i 
 
 19 
 
 
 19 
 
 7 
 
 19 
 
 10 
 
 20 
 
 8 
 
 39 
 
 
 40 
 
 2f 
 
 40 
 
 H 
 
 41 
 
 3f 
 
 19 
 
 6 
 
 20 
 
 u 
 
 20 
 
 H 
 
 21 
 
 2i 
 
 39 
 
 6 
 
 40 
 
 8| 
 
 40 
 
 llf 
 
 41 
 
 H 
 
 20 
 
 
 20 
 
 '1 
 
 20 
 
 lOf 
 
 21 
 
 8f 
 
 40 
 
 
 41 
 
 2| 
 
 41 
 
 5i 
 
 42 
 
 H 
 
 20 
 
 6 
 
 21 
 
 u 
 
 21 
 
 H 
 
 22 
 
 2i 
 
 40 
 
 6 
 
 41 
 
 9 
 
 42 
 
 
 
 42 
 
 10 
 
 21 
 
 
 21 
 
 n 
 
 21 
 
 m 
 
 22 
 
 8f 
 
 41 
 
 
 42 
 
 3i 
 
 42 
 
 H 
 
 43 
 
 4i 
 
 21 
 
 6 
 
 22 
 
 n 
 
 22 
 
 H 
 
 23 
 
 2^ 
 
 41 
 
 6 
 
 42 
 
 n 
 
 43 
 
 Of 
 
 43 
 
 lOf 
 
 22 
 
 
 22 
 
 8i 
 
 22 
 
 IH 
 
 23 
 
 H 
 
 42 
 
 
 43 
 
 3i 
 
 43 
 
 ^ 
 
 44 
 
 4i 
 
 22 
 
 6 
 
 23 
 
 2i 
 
 23 
 
 H 
 
 24 
 
 3i 
 
 42 
 
 6 
 
 43 
 
 91 
 
 44 
 
 Oi 
 
 44 
 
 lOf 
 
1184 
 
 RAILROAD STRUCTURES. 
 
 posts should be spaced from 4 to 5 feet between centers, and 
 the batter posts 11 feet from center to center at the top. 
 The inclined posts should have a batter of 3 inches to the 
 foot. This gives a broad base, adding considerably to the 
 stiffness and stability of the structure. It is poor economy 
 to stint the dimensions of trestle timbers. It is far better to 
 have an excess of strength than a lack of it, and the addition 
 of one or two inches to any dimension involves but a slight 
 increase in cost and makes safety certain. 
 
 Table 44 gives the length of batter posts for different 
 heights at an inclination of 3 inches per foot. 
 
 The first column gives the vertical height of the bent 
 from top of sill to base of cap. The second column gives 
 the length of the post as measured along either edge after the 
 end is cut to the proper angle. The third column gives the 
 length of the timber with square ends required to cut 
 the post, and the fourth column the length of stick required 
 to give a tenon 5 inches long on both ends of post. 
 
 The table is used as follows: The height of a bent from 
 base of sill to top of cap is 25 ft., the cap and sill are each 
 12 in. by 12 in. ; what length of timber is required for posts 
 to batter 3 in. to the foot and give a 5-in. tenon at both 
 ends ? Deducting 2 ft. from 25 ft., the total height of bent, 
 we have 23 ft., the distance between cap and sill. Referring 
 to the table we find in the fourth column opposite 23 ft., 
 24 ft. 9^ in., the required length of the posts. 
 
 1750. Batter post templates set at the proper angle 
 
 are very convenient for cutting 
 the ends of posts. A piece of 
 ^-inch hard wood board cut 
 to the proper angle with a 
 1-inch cleat fastened to the 
 edge of the board, to fit against 
 the edge of the batter post, 
 serves the purpose well. A 
 template of this description is 
 Fig. 570. shown in Fig. 570. 
 
RAILROAD STRUCTURES. 
 
 1185 
 
 Some designers place the plumb and batter posts so as to 
 touch each other where they meet the caps (Fig. 571). 
 
 Fig. 571. 
 
 FIG. 572. 
 
 When all the posts are battered, the distance between them 
 at the top is fixed. 
 
 The outside posts have a uniform batter irrespective of 
 height, while the inside posts change their batter with each 
 change of height (Fig. 572). 
 
 The caps, if solid, should be of not more than 12-in. by 
 r2-in. timber. In a majority of cases 10-in. by 10-in. tim- 
 ber would serve equally well, often insuring better timber 
 and resulting in considerable saving of material. There are 
 several different ways of joining the sills, posts, and caps 
 together, but only three are iii general use, viz., by mortise 
 and tenon,. by drift bolts, and by dowels. 
 
 A tenon 3 inches thick, 8 inches wide, and 5 inches long is 
 a good size. The mortise should be about ^ inch deeper 
 than the length of the tenon and well finished, so that the 
 tenon will fit snugly. In boring the hole for the treenail, 
 the same precaution should be taken with framed bents as 
 with pile bents. All mortises so placed as to hold water 
 should be provided with drip holes. 
 
 1751. The use of drift bolts in connecting cap and sill 
 with posts is shown in Fig. 573, and dowel connections in 
 Fig. 574. 
 
 Two drift bolts are required to fasten a post to the sill 
 and one to secure it to the cap. A hole must be bored 
 for each drift bolt, two sizes of holes being used. The first 
 hole is slightly smaller than the drift bolt, the second hole 
 still smaller. The drift bolts used for these connections are 
 
118G 
 
 RAILROAD STRUCTURES. 
 
 either of square or round iron. If square, f inch will 
 answer, or iron of equivalent weight, if round. Dowels are 
 usually of f-inch round iron. 
 
 X 
 
 Fig. 573. 
 
 Fig. 574. 
 
 Split caps and sills are preferred on some roads, and 
 when used, the connections with the posts are made similar 
 to split cap connections of pile trestles (see Fig. 561). 
 
 It is customary to notch both cap and sill at the post 
 
 joints. Both square 
 and beveled notches 
 are employed (see 
 Figs. 575 and 576), 
 Fig. 575. Fig. 576. though the former 
 
 (Fig. 575) is to be preferred. 
 
 Bents should be uniformly spaced, the distance between 
 centers of bents being from 12 to 16 feet, depending upon 
 the character and cost of timber. Spans from 12 to 14 feet 
 are most common. 
 
 FLOOR SYSTEM. 
 1752. Corbels. — Corbels are placed lengthwise the 
 stringers and between them and the caps. They are not 
 
 Fig. 577. 
 
 Fig 578 
 
 favored by the best designers, and do not appear in most 
 trestles of recent construction. Corbels are usually frona 
 
RAILROAD STRUCTURES. 
 
 1187 
 
 4 to 8 feet long, extending equal distances each side of the 
 cap. They are usually notched down on the caps, and often 
 doweled to them. The stringers are bolted to the corbels, 
 which virtually shorten the span, so that lighter stringers 
 may be used with corbels than without them. If, however, 
 the cost of the corbels was expended in increasing the size 
 of the stringers, an equally strong and considerably simpler 
 structure would be the result. Two common types of 
 corbels are shown in Figs. 577 and 578. 
 
 1753. Stringers. — A stringer is usually placed direct- 
 ly beneath each rail, and instead of a single piece of timber, 
 it should be composed of two or more smaller pieces which 
 combined possess the requisite strength. Smaller sizes of 
 timber are less expensive and less liable to conceal dama- 
 ging defects. * These pieces should be separated from each 
 
 ^ \ '-0' J „„„___ 
 .1 \^ ^^ 
 
 Fig. 579. 
 
 Fig, 
 
 Fig. 581. 
 
 Fig. 582. 
 
 Fig. 583. 
 
 Fig. 584. 
 
 Other either by cast-iron separators^ or by packing-blocks^ or 
 both. The distance apart at which stringers are placed 
 varies widely, ranging from nothing to 10 or 12 inches. A 
 safe distance is 3 inches, the space being occupied by both a 
 separator and a packing-block. Common types of separators 
 are given in Figs. 579 to 584. 
 
 The prime object of the separator is to hold the stringers 
 apart from each other, and so prevent the accumulation of 
 moisture, which would soon induce decay. 
 
 1754. Packing-blocks are pieces of plank from 4 to 
 6 feet in length placed between the stringers and over the 
 caps. They extend equally in both directions from the cap, 
 and some contain a notch which fits down over the cap. 
 They serve to strengthen the connection between cap and 
 stringer, and, together with the separators, maintain the 
 space between the stringers. 
 
1188 
 
 RAILROAD STRUCTURES. 
 
 There are several styles of packing-blocks, among which 
 are those shown in Figs. 585, 58G, and 587. Of these the 
 type shown in Fig. 587 is recommended. This block is 6 
 
 Fig. 585. 
 
 Fig. 586. 
 
 Fig. 587. 
 
 feet in length and 2 inches in thickness. Four |-inch bolts 
 pass through both stringers and packing-block. Separators 
 ^ inch thick (see Fig. 579) are placed between the stringer 
 and packing-block, the stringer or packing-bolts passing 
 through the separators and holding them in place. 
 
 1755. Wherever practicable, the stringer should be 
 long enough to cover two spans, so as to break joints on the 
 caps. Some provision should be made for holding the 
 stringers firmly in place. This is usually effected by drift- 
 bolting the stringers to the caps. One objection to this 
 mode of fastening stringers is the great difficulty in remov- 
 ing the bolts when repairs are to be made. To obviate this 
 difficulty, pieces of 3-inch by 12-inch plank of such length 
 as to give to the stringers the proper spacing are placed be 
 tween the stringers, being fastened to the caps by spikes or 
 lag-screws. These pieces of plank are called spreaders, and 
 they are already much in favor. 
 
 1 756. Stringer Joints. — There are many different 
 styles of stringer joints employed on American roads, 
 
 d 
 
 ^ 
 
 3 
 
 ^ fe 
 
 1 
 
 nif^ 
 
 I 
 
 Fig. 688. Fig. 580. 
 
 among which those shown in Figs. 588 to 591 have especial 
 merit. 
 
RAILROAD STRUCTURES. 
 
 1189 
 
 The joint shown in Fig. 588 is especially recommended- 
 It is simple, strong, and withstands decay. In case the sup- 
 ports should settle so as to practically double the span, the 
 
 n 
 
 ^ » I I? f- 
 
 .^44Tr1 
 
 ^xr 
 
 3 E 
 
 "n 
 
 Fig. 590. 
 
 Fig. 591. 
 
 joint is SO constructed as to best resist this strain. Any 
 tendency to settle is at once counteracted by the packing- 
 bolts, which must either break or split the stringer before 
 the joint can fail. The strain is greatest on the lower bolts, 
 which are placed furthest from the joint, where they are 
 least likely to split the stringer. This joint would be im- 
 proved by placing a separator, like that shown in Fig. 579, 
 between each stringer and the packing-block. This would 
 make the space between the stringers 3 inches. 
 
 To prevent longitudinal movement, stringers must be 
 either notched down one inch on the caps or drift-bolted 
 to them. All packing-bolts should be long enough to 
 receive a cast wasJier under 
 both head and nut. The 
 difficulty of removing drift- 
 bolts when making repairs 
 has already been mentioned. 
 By notching down the string- 
 ers on the caps, and by placing 
 a spreader a between them 
 (see Fig. 502), all lateral 
 movement is prevented. The 
 spreaders are fastened to the 
 caps either by lag - screws or fig. tm. 
 
1190 
 
 RAILROAD STRUCTURES. 
 
 by spikes. By notching down the ties 1 inch on the stringers 
 (see b^ Fig. 592), the spacing of the stringers is maintained, 
 and the ties held rigidly in place. 
 
 1757. Size of Stringers. — The size of the stringer 
 pieces in section will depend upon the length of the span 
 and the character of the traffic. Two is the number of 
 pieces generally used. They should be of sufficient dimen- 
 sions to carry the heaviest train load without any consider- 
 able deflection. A stringer more used on American roads 
 than all others has the following dimensions : Width, 8 inches ; 
 depth, IG inches, and length varying from 2-4 to 28 feet. 
 Each rail is supported by two such pieces, making four for 
 a complete span. Yellow or Southern pine is generally 
 used, though white pine, Oregon pine, spruce, or even hem- 
 lock of these dimensions, if sound, will carry any train load 
 ordinarily hauled on American lines. Dimensions of track 
 stringers used on the Pennsylvania Railroad are given in 
 Table 45. 
 
 TABLE 45. 
 
 TRESTLE STRINGERS, PENNSYLVANIA RAILROAD 
 STANDARD. 
 
 Dimensions of Stringers. 
 
 Clear Span. 
 
 Number of Pieces 
 under Each Rail. 
 
 Width of Each 
 Piece. 
 
 Depth of 
 Stringers. 
 
 10 ft. 
 
 2 
 
 8 in. 
 
 15 in. 
 
 12 ft. 
 
 2 
 
 8 in. 
 
 IG in. 
 
 Uft. 
 
 2 
 
 10 in. 
 
 17 in. 
 
 IG ft. 
 
 3 
 
 8 in. 
 
 17 in. 
 
 1758. A jack-stringer composed of a single piece, 
 and shown at c in Fig. 592, is often placed near the ends 
 of the ties and directly beneath the guard-rail, the object of 
 which is to afford additional support to the ties in case of 
 
RAILROAD STRUCTURES. 
 
 1191 
 
 derailment. Without this support the ties are likely to be 
 broken by a derailed engine, and a total wreck follow, while 
 with it, providing the guard-rail holds, the engine and train 
 are likely to remain on the trestle. This greatly increases 
 the factor of safety. The jack-stringers should reach over 
 two spans, breaking joints alternately, and be drift-bolted 
 to the caps. The ends of the stringers should abut against 
 each other, though there are a few instances to the contrary. 
 
 1759. Ties. — Trestle ties vary in both section and 
 length. A good size is 7 in. by 8 in. by 12 ft. in length. 
 
 -«# 
 
 3 
 
 iS 
 
 nnnnnnrin 
 
 yi5- 
 
 '-^ 
 
 z 
 
 qrike 
 
 8L(tg-screw 
 
 Fig. 593. 
 
 "^Ij lj u u u u u G 
 
 8 Lug screw 
 
 Fig. 594. 
 
 ¥^ 
 
 This length provides for a jack-stringer. Many ties are 
 only 9 feet in length, while others are 10 feet. They are 
 spaced from 12 to 24 inches between centers, though 15 inches 
 
 }Bolt 
 
 ixl3 Boat spike 
 
 n n n n n nxni ^ 
 
 ^lll^^llMjw fe^ rSi,"^"^"^ 
 
 Fig. 595. 
 
 Fig. 596. 
 
 should be the limit. The reason for placing them close 
 together is that, in case of derailment, ties closely spaced 
 
1192 RAILROAD STRUCTURES. 
 
 afford a fairly continuous support for the car wheels, es- 
 pecially the driving wheels, while those widely spaced allow 
 the wheels to drop between, and the ties are torn up, and a 
 wreck is likely to follow. On some roads, none of the ties are 
 fastened to the stringers; on others, every fifth, or even 
 every other, tie is fastened, spikes or lag-screws being gen- 
 erally used for the purpose. Dowels are used for tie fasten- 
 ings, but only in a limited way, the only important road 
 employing them being the Louisville and Nashville Railroad 
 (Fig. 597). Four different standard floor systems are given 
 in Figs. 593 to 596, showing the arrangement and mode of 
 fastening cross-ties. In the Pennsylvania standard, the wide 
 
 spaces between the ties are 
 a serious objection, as in 
 case of derailment it ren- 
 ders wreck almost certain. 
 The dimensions and arrange- 
 ^"'^- °^- ment of ties in Fig. 594 are 
 
 especially recommended. Ties should always be notched 
 down 1 inch over the stringers. Notching prevents any 
 lateral movement and strengthens the floor system. 
 
 1760. Guard-Rails. — Guard-rails are an important 
 part of the trestle. Their purpose is twofold, viz., first, to 
 prevent a train from leaving the bridge in case of derail- 
 ment, and, second, to maintain the spacing of the ties and 
 add weight and strength to the floor system. Where a 
 jack-stringer is used, the guard-rail is placed directly above 
 it. Guard-rails should be notched down upon the ties, 
 usually 1 inch, and fastened to them either with bolts or 
 lag-screws. Guard-rails in section should be not less than 
 G by 8 inches, the length depending on the available supply, 
 but no length under 16 feet should be used. Commonly the 
 guard-rails and cross-ties are of the same sized timber, 7 by 
 8 inches being a standard size, the lengths running from 20 
 to 24 feet. They are spliced in a variety of ways. Various 
 forms of splices are shown in Figs. 598 to 601. The halved 
 joint (Fig. 598) is recommended as simple and effective. 
 
RAILROAD STRUCTURES. ll'J3 
 
 Joints should come directly over a tie and be broken, i. e., 
 a joint on one guard-rail should be on line with the middle 
 point of the opposite guard-rail. Each joint should be 
 fastened with either a bolt or a lag-screw. Bolts are to be 
 much preferred to lag-screws for fastening guard-rails to 
 ties. Lag-screws tear the fiber of the wood, and form 
 cavities which hold moisture and induce decay. The best 
 plan is to bolt every fourth or fifth tie to the guard-rail, and 
 
 r I { uuu Trn 
 
 2 )■ ,^o»'~' ^ ^«=5=i^ ^^ ^=a=^ 
 
 Fig. 598. Fig. 599. Fig. 600. Fig. 601. Fig. 602. Fig. 603. 
 
 spike the remaining ties with 10-inch boat spikes. A 
 puncJied washer should be put under the head of each lag- 
 screw. It is a waste of time and an injury to the timber to 
 countersink the heads of bolts or lag-screws. The holes 
 form receptacles for water, which soon induces decay. A 
 3 to 3^-inch cast washer should be placed under the head and 
 nut of each bolt, the nut being placed up so as to make 
 inspection and repairs easy. 
 
 1761. The ends of the guard-rail should be beveled, as 
 shown in Fig. 602 or G03. The guard-rails should extend 
 from 20 to 30 feet from the trestle on to the embankment. 
 They should be flared outwards so that at their extremities 
 they will be from 3 to 4 feet from the rails. The object of 
 flaring the guard-rails is to assist any car which may have 
 been derailed on the embankment in passing the trestle in 
 safety (see Fig. 604). On some roads, in addition to 
 these flaring guards, bumping posts are placed near the 
 end of the embankment, but their value is not generally 
 admitted. 
 
 An additional safeguard, and one in general use on some 
 lines, is an inner guard-rail of the same section as the main 
 rail, placed 2^ inches inside the rail. Objection is made by 
 some to this form of guard-rail on the ground of its forming 
 
1194 
 
 RAILROAD STRUCTURES. 
 
 a lodgment for detached pieces of the truck, such as brake 
 shoes, box lids, etc., causing the wheels to mount the rails. 
 The tendency of wheels to mount the wooden guards may be 
 
 cr-ilj iy iiijfj ill ij 
 
 Fig. 604. 
 
 prevented by fastening a strip of angle iron on the upper 
 inside edge of the guard-rail. 
 
 1762. Fastening Down Floor System. — There 
 are several different methods of fastening the floor system 
 down to the bents, some of which have already been men- 
 tioned. The method generally adopted is to drift-bolt the 
 Hs-1 r^ ,\H stringersto the caps (Fig. G05). 
 
 The only objection to this 
 method has already been 
 /- Ul UL stated, viz., the difficulty of 
 
 removing the bolts when 
 making repairs. This mode 
 of fastening the floor system 
 has the merits of simplicity 
 mJ m \A\ and security, and is more used 
 
 ^''<^-^<'5- than all others. Another 
 
 method is to bolt the stringers to the caps, in which case the 
 posts must be so spaced as to allow the bolt to pass through 
 the cap. On some roads the stringers are not fastened to 
 the caps, the weight of the floor system being depended 
 
RAILROAD STRUCTURES. 
 
 1195 
 
 upon to hold them down. In such cases the stringers must 
 be notched down 1 inch upon the caps and spreaders, as 
 shown in Fig. 592, used to prevent lateral movement. 
 
 Bents 
 
 Fig. 606. 
 
 BRACING. 
 1763. Sway-Bracing. — Pile or framed bents under 
 10 feet in height seldom require any sway-bracing, 
 from 10 to 20 feet in height require a 
 single X brace of 3-inch by 10-inch 
 planks extending diagonally from the 
 upper corner of the cap to the foot of 
 the opposite pile or to the outside 
 corner of the sill, if a framed bent 
 (see Fig. 606). For bents from 20 to 
 40 feet in height, two X braces separa- 
 ted by 3-inch by 10-inch horizontal planks spiked to both sides 
 of the bent, as shown in Fig. 607, afford ample bracing. There 
 
 are two methods of fastening 
 the sway-braces, both in gen- 
 eral use. In one, the sway 
 braces are fastened to the 
 piles or posts with f-inch 
 bolts and cast washers, as 
 shown in Fig. 606; in the 
 other, they are spiked with ^- 
 inch by 8-inch boat spikes. 
 Bolt fastenings may be easily 
 removed without damaging 
 the braces, which may be 
 used a second time, if not 
 ^'"'"- ^~- decayed. Spikes, on the 
 
 other hand, are difficult to draw, and sway-braces are often 
 split or broken in removing them from the bents. However, 
 second-hand trestle material is of little value, and as spikes 
 are a sure fastening and cheaper and more expeditious 
 than bolts, they are to be recommended. 
 
 When the piles of a bent are out of line so that the 
 sway-brace can not lie flat, they should either be hewn so that 
 
1196 RAILROAD STRUCTURES. 
 
 the sway-brace will come in direct contact with every pile or 
 post, or a packing piece of the necessary thickness should be 
 placed under the sway-brace to give it a full bearing on the 
 bent. 
 
 1764. Counter Posts. — Framed bents exceeding a 
 height of 30 feet are frequently stiffened by counter posts a h 
 and c d, shown in Fig. 025, Art. 1 792, in the section on 
 Standard Trestles. Counter posts require the dividing up of 
 the bent into two or more stories by means of an intermediate 
 sill cf. They are generally employed in high work where 
 two and sometimes three sets of counters are used. 
 
 1 766. Longitudinal Bracing. — This form of bracing 
 is employed in various ways — some bracing every bay or 
 span, others every third or fourth bay. In some trestles 
 the bracing is placed diagonally, in others horizontally, 
 while some employ both forms. 
 
 Fig. 623, Art. 1 790, under Standard Trestles, shows the 
 laced iovm. of longitudinal bracing as employed by the Penn- 
 sylvania Railroad.. The caps and sills are chamfered, and the 
 braces cut to fit them, as shown in the detail at A. The 
 braces are fastened to both cap and sill by heavy cut spikes. 
 
 1766. Lateral Bracing. — Lateral bracing, shown at 
 a b m Fig. G2G, Art. 1793,. in section on Standard Trestles, 
 adds much to the stiffness of a structure. These braces are 
 usually of G-in. by 6-in. timber, bolted together at their in- 
 tersection c with either #-in. or ^-in. bolts. They are slightly 
 notched into the caps, to which they are fastened with heavy 
 cut spikes. They contribute much towards keeping the 
 track in line, and serve to a considerable extent the purpose 
 of longitudinal bracing. Whatever the style of bracing 
 employed, it must be borne in mind that the effectiveness 
 of bracing depends largely upon the thoroughness with which 
 it is fastened to the parts to be strengthened. Sway-bracing 
 is usually fastened to the cap and sill with f-in. bolts, and 
 spiked to the posts or piles with boat spikes. Diagonal 
 braces, especially those framed or notched into the bent 
 timber, are frequently found loose and ineffective. When 
 
RAILROAD STRUCTURES. 
 
 1197 
 
 Fig. C08. 
 
 spiked or bolted to place, they should fit snugly and be at 
 least slightly strained. 
 
 1767. Trestles on Curves. — Wherever possible, 
 curved trestles should be avoided. The additional stress due 
 to the centrifugal force of ^ ^-w— ^-9- 
 
 heavy trains at high' speed 
 is a severe tax upon a 
 structure, and the locating 
 engineer should, if pos- 
 sible, so modify his line as 
 to place all trestles on 
 tangents. Circumstances, however, sometimes render the 
 curved trestle a necessity, in which case the outer posts 
 vy^f a. g ^ INitch must have an increased 
 
 batter and the outer rail its 
 proper elevation. 
 
 There are various meth- 
 ods of elevating track on 
 curved trestles, three of 
 Fig. 609. which are shown in Figs. 
 
 608, 609, and 610. In Fig. 608 the elevation is effected by 
 cutting off the piles or framing the posts to such lengths as 
 will afford the requisite 
 elevation. This is the sim- 
 plest and easiest method of 
 elevating the outer rail of a 
 trestle. There are no shims 
 to get out of place or need ^y 
 renewing, and there is no 
 increase in cost above that 
 of a trestle on a straight line. 
 
 In Fig. 609 the outer rail is elevated by means of a shim /", 
 which is placed under the rail and fastened to the tie with 
 cut spikes. The weak point in this mode of elevating the 
 outer rail, aside from the cost of making and fastening the 
 shims, is the accumulation of moisture under the shims, 
 which induces their decay and the decay of the ties also. 
 
 Fig. CIO. 
 
1198 
 
 RAILROAD STRUCTURES. 
 
 In Fig. GIO the elevation is effected by cutting away a 
 portion of the cap at a to an amount equal to the required 
 elevation. The stringers are then placed in a horizontal 
 position, as shown in the figure, and the notches in the ties 
 beveled so as to fit the top of the stringers. In pile bents, 
 the caps are usually drift-bolted to the piles, and in framed 
 bents the connection is usually made with mortise and ten- 
 on. In all three methods, the stringers are drift-bolted to 
 the caps. In Figs. G08 and 009, the jack-stringers a and b 
 add considerable to the stability of the structures, and are 
 an additional safeguard in case of derailment. The eleva- 
 tion of the outer rail in each case is 3 inches, and the degree 
 of the curves 6 degrees. Both posts or piles c^ d on the out- 
 side of the curve are battered, the outside one at a batter of 
 4 inches to the foot, and the next inside 2 inches to the 
 foot. On the inside of the curve, only the outside posts or 
 piles e of the bent are battered, and at the usual batter of 3 
 inches to the foot. If the trestle is a high one, it should be 
 strengthened by additional bracing. 
 
 IRON DETAILS. 
 
 1768. 
 
 trestle building, viz., 
 
 Spikes. — There are two kinds of spikes used in 
 cut spikes (Fig. Oil), which are 
 formed like ordinary cut nails and 
 manufactured in the same way, and 
 boat spikes (Fig. 012), which are 
 forged from bars of wrought iron. 
 Spikes of the same length are not 
 necessarily of the same weight. 
 Slender spikes are not suited for 
 trestle building, as they are liable 
 to bend and break, besides lacking 
 in holding power. Those having good sized heads and 
 bodies should always be used. Steel spikes are to be pre- 
 ferred to iron ones, as they are tougher and stronger. 
 
 Boat spikes, shown in Fig. 012, have strong, well-formed 
 heads, and are chisel pointed. They are used to fasten 
 
 L 
 
 W 
 
 FiG.en. Fig. 612. Fig. 613. 
 
RAILROAD STRUCTURES. 
 
 1199 
 
 guard-rails to ties, ties to stringers, and sway-bracing to the 
 bents. 
 
 Table 46 gives sizes and weights and numbers of spikes in 
 a keg of 100 pounds : 
 
 TABLE 46. 
 
 CUT SPIKES. 
 
 Length 
 in Inches 
 
 3 
 
 H 
 
 4 
 5 
 
 No. in Keg 
 of 100 lb. 
 
 2,900 
 2,100 
 1,500 
 1,150 
 950 
 
 Weight of 
 
 One Spike, 
 
 lb. 
 
 Length 
 in Inches 
 
 .0344 
 
 5i 
 
 .0476 
 
 6 
 
 .0667 
 
 H 
 
 .0869 
 
 7 
 
 .1052 
 
 8 
 
 No. in Keg 
 of 100 lb. 
 
 850 
 775 
 575 
 450 
 375 
 
 Weight of 
 
 One Spike, 
 
 lb. 
 
 .1176 
 .1293 
 .1739 
 .2222 
 
 .2666 
 
 Table 47 gives the lengths of the different sizes of boat 
 spikes, the approximate number of each in a keg of 150 
 pounds, and the weight of each. 
 
 1769. Drift Bolts. — Drift bolts commonly resemble 
 boat spikes in shape, but they are much larger. The heads 
 are less carefully shaped, and often they are used without 
 either head or point, the bolts being simply sheared from 
 rods to a proper length, and driven into the holes bored 
 to receive them. The ordinary shapes are shown in Fig. 
 613. For fastening 12-inch caps to posts or piles, drift 
 bolts of f-inch square or |-inch round iron and 20 inches 
 long are commonly used. They should always penetrate 
 the last timber into which they are driven a sufficient dis- 
 tance to resist any legitimate pull or shock which will be 
 placed upon them. Holes are always bored to receive drift- 
 bolts. They should be of such size that, in driving, the 
 fibers of the wood will fill all space not occupied by the bolt 
 itself. 
 
1200 
 
 RAILROAD STRUCTURES. 
 
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RAILROAD STRUCTURES. 
 
 1201 
 
 Table 48 gives the weight of drift-bolts of the sizes 
 commonly used: 
 
 TABLE 48. 
 
 IJVEIGHTS OF DRIFT-BOLTS. 
 
 Length in Inches. 
 
 Square Section. 
 
 Round Section. 
 
 f in. sq. 
 
 1 in. sq. 
 
 f in. diam. 
 
 1 in. diam. 
 
 18 
 20 
 22 
 24 
 26 
 
 Lb. 
 2.9 
 3.2 
 3.5 
 3.8 
 4.1 
 
 Lb. 
 
 5.1 
 5.7 
 6.2 
 6.8 
 7.3 
 
 Lb. 
 2.3 
 2.5 
 2.8 
 3.0 
 3.3 
 
 Lb. 
 4.0 
 4.4 
 4.9 
 5.3 
 5.8 
 
 1770. The main value of drift-bolts lies in their hold- 
 ing power. A long series of experiments by the United 
 States Engineer Corps, made while building the St. Mary's 
 Canal locks, developed the following results: 
 
 The mean of from 150 to 200 experiments with round and 
 square bolts, both smooth and ragged, in different-sized 
 holes, shows that the resistance after having been driven 
 seven months is 10 per cent, greater than the resistance 
 immediately after driving, the different sizes and forms 
 being strictly uniform. 
 
 The mean of 150 experiments under various conditions 
 shows that the resistance to being drawn in the direction in 
 which the bolts were driven is only 60 per cent, of their 
 resistance to being drawn in the opposite direction; that is 
 to say, the resistance to being drawn through is only 60 per 
 cent, of the resistance to being drawn back. The mean of 
 50 experiments shows that smooth rods have a greater 
 resistance than ragged bolts, both to being drawn through 
 and also to being drawn back; that a moderate ragging 
 reduces the holding power a little more than 25 per cent., 
 and an excessive ragging reduces the holding power more 
 than 50 per cent. 
 
1202 RAILROAD STRUCTURES. 
 
 The best relation between the diameter of the bolt and 
 that of the hole, as determined by one series of 60 experi- 
 ments, shows that the holding power of a 1-inch-round bolt 
 in a l^-inchhole is greater than in a ff-inch or a ||-inch hole, 
 the resistance in a |^|-inch hole being 98 per cent, and that 
 in a f|-inch hole being 90 per cent, of that in a [^-inch hole. 
 Another series of 35 experiments makes the holding power 
 of a 1-inch round bolt in a ||-inch hole greater than in a |f 
 or a ||-inch hole, the first two being practically the same, 
 and the last being only 85 per cent, of the first. For a 
 f-inch round bolt four experiments with each size prove that 
 the holding power of the bolt in a |f-inch hole is about one 
 quarter greater than in a y^-inch or a ^-inch hole. For a 
 1-inch square bolt, the holding power in a ||^-inch hole is only 
 a. trifle greater than in a [f-inch hole, and about 20 per cent, 
 greater than in a [f-inch hole, as deduced from 20 to 40 
 experiments for each size of hole. 
 
 The holding power of a 1-inch square bolt in a f|-inch 
 hole was practically the same as for a 1-inch round rod in a 
 l^-inch hole. There is 25 per cent, more metal in the 
 square drift-bolt and more labor is required in boring a ||- 
 inch hole than in boring a f^-inch hole; hence, the round 
 drift-bolt is 25 per cent, more efficient than the square one. 
 
 In the matter of pointing the bolts, experiment goes to 
 prove that drift-bolts with a long, slender point have about 
 10 per cent, greater resistance than those with short, blunt 
 points, the conclusion being that the blunt points tear the 
 fiber of the wood, while the slender points crowd it aside, 
 filling up the cavities of the hole, thereby increasing the 
 friction of the bolt. 
 
 1771. no-wels. — In place of drift-bolts, short iron 
 rods, either square or round, called do>vels, are frequently 
 used. They have neither point nor head, but are sheared 
 from rods, care only being taken to make them straight. 
 They are frequently used to fasten caps to posts, posts to 
 sills, and ties to stringers. A common size of dowel for 
 fastening caps to posts and posts to sills is f-inch round or 
 square by 8 inches in length, weighing about 1 pound each. 
 
RAILROAD STRUCTURES. 
 
 1203 
 
 Dowels of f-inch round iron, 5 inches in length, are well 
 suited for fastening ties to stringers. 
 
 The following list gives the weight of 1-inch lengths of 
 the various sizes of iron bars or rods commonly employed 
 in this kind of work: 
 
 1 in. 
 
 square 
 
 0.2806 lb. 
 
 |in. 
 
 diam. round 
 
 0.1240 lb. 
 
 I in. 
 
 diam. round 
 
 0.2204 1b. 
 
 fin. 
 
 square 
 
 0. 1096 lb. 
 
 Jin. 
 
 square 
 
 0.2149 lb. 
 
 fin. 
 
 diam. round 
 
 0.0860 lb. 
 
 |in. 
 
 diam. round 
 
 0.1687 lb. 
 
 i in. 
 
 square 
 
 0.0701 lb. 
 
 f in. 
 
 square 
 
 0.1579 lb. 
 
 i in. 
 
 diam. round 
 
 0.0551 lb. 
 
 1772. Bolts. — Bolts for holding the stringer pieces 
 together, fastening the braces, guard-rails, etc., are com- 
 monly of f-inch round iron, their lengths, of course, de- 
 pending upon the purpose for which they are to be 
 used. The bolt heads should be well formed, and 
 of good weight, and the threads right-handed and 
 well cut. 
 
 & Bolt heads are of three forms — button heads, flat 
 
 ■ '^ countersunk heads, and the ordinary square heads 
 
 Fig. 614. (Fig- 614). Square nuts with a thickness equal to 
 
 the diameter of the bolt and length of side equal to twice 
 
 the diameter of the bolt are the best. The outer top 
 
 corners of both head and nut should be chamfered. 
 
 A cast-iron washer from 3 to 3^ inches in diameter should 
 be placed under the head and nut of all bolts. Holes of 
 y*^ inch less diameter than the bolts are bored through the 
 timber to receive the bolts to insure a close fit. 
 
 Table 49 gives sizes and weights of bolts, and though 
 not exact, owing to the varying weights of heads, is amply 
 close for approximate estimates. 
 
 In ordering bolts, the term grip^ as sometimes employed, 
 signifies the total thickness of the material to be held 
 together; in other words, the distance between the inside 
 faces of washers. 
 
 1773. Lag-Screws. — A lag-screw is a large wood 
 screw which serves in place of a bolt. The head is shaped 
 
1204 
 
 RAILROAD STRUCTURES. 
 
 TABLE 49. 
 
 APPROXIMATE WEIGHT OF BOLTS IN POUNDS, WITH 
 SQUARE HEADS AND NUTS, INCLUDING BOTH. 
 
 Length 
 
 Under Head 
 
 in Inches. 
 
 Diameter in Inches. 
 
 i 
 
 f 
 
 f 
 
 1 
 
 1 
 
 6 
 
 0.59 
 
 1.01 
 
 
 
 
 7 
 
 0.G4 
 
 1.10 
 
 
 
 
 8 
 
 0.70 
 
 1.19 
 
 
 
 
 9 
 
 0.75 
 
 1.27 
 
 
 
 
 10 
 
 0.81 
 
 1.3G 
 
 2.10 
 
 3.05 
 
 4.23 
 
 11 
 
 0.8G 
 
 1.44 
 
 2.22 
 
 3.22 
 
 4.45 
 
 12 
 
 0.92 
 
 1.53 
 
 2.35 
 
 3.39 
 
 4.67 
 
 13 
 
 0.97 
 
 1.62 
 
 2.47 
 
 3.55 
 
 4.89 
 
 14 
 
 1.03 
 
 1.70 
 
 2.59 
 
 3.72 
 
 5.11 
 
 15 
 
 1.08 
 
 1.79 
 
 2.72 
 
 3.89 
 
 5.34 
 
 IG 
 
 
 1.87 
 
 2.84 
 
 4.06 
 
 5.56 
 
 17 
 
 
 1.96 
 
 2.97 
 
 4.23 
 
 5.78 
 
 18 
 
 
 2.05 
 
 3.09 
 
 4.40 
 
 6.00 
 
 19 
 
 
 
 3.21 
 
 4.57 
 
 6.22 
 
 20 
 
 
 
 3.34 
 
 4.74 
 
 6.44 
 
 21 
 
 
 
 3.46 
 
 4.90 
 
 6.66 
 
 22 
 
 
 
 3.59 
 
 5.07 
 
 6.88 
 
 23 
 
 
 
 3.71 
 
 5.24 
 
 7.10 
 
 24 
 
 
 
 3.83 
 
 5.41 
 
 7.32 
 
 like a bolt head, and an ordinary wrench may be 
 used in fastening the screw in place. A hole of the 
 full size of the shank of the screw is bored through 
 the first timber and a much smaller one is bored for 
 the balance of the distance through which the thread 
 is to pass. A wrought or punched washer cut from 
 sheet iron should be placed under the head of 
 each lag-screw. The ordinary form of lag-screw is 
 in Fig. 615, 
 
 Fig. 615. 
 
 shown 
 
RAILROAD STRUCTURES. 
 
 1205 
 
 1774. Washers. — Cast washers are largely used in 
 trestle building. One should be placed under the head and 
 nut of every bolt used in the structure. The more common 
 forms of cast washers are shown in Fig. 616, and their 
 
 dimensions are given in Table 50. The solid washers are 
 placed under the head and the slotted washers, or those 
 
 TABLE 50. 
 
 DETAILS OF CAST-IRON WASHERS. 
 
 
 
 Dimensions 
 
 , in Inches. 
 
 
 Kind, Fig. 616. 
 
 
 
 
 
 
 Diameter 
 
 Diameter 
 
 Diameter 
 
 Thickness. 
 
 
 of Back. 
 
 of Face. 
 
 of Hole. 
 
 A 
 
 n 
 
 If 
 
 1 
 
 i 
 
 B 
 
 3 
 
 2i 
 
 1 
 
 i 
 
 C 
 
 3 
 
 If 
 
 1 
 
 f 
 
 D 
 
 3 
 
 2 
 
 1 
 
 1 
 
 E 
 
 3 
 
 li 
 
 I 
 
 I 
 
 F 
 
 3 
 
 2 
 
 f 
 
 i 
 
 G 
 
 3i 
 
 2i 
 
 1 
 
 * 
 
 H 
 
 3| 
 
 2i 
 
 li\ 
 
 f 
 
 K 
 
 4 
 
 2 
 
 1 
 
 t 
 
 L 
 
 4f 
 
 2f 
 
 I 
 
 1 
 J, 
 
 having a second hole, under the nut. The purpose of the 
 slot, or second hole, is to provide for locking the nut. After 
 
] 20G 
 
 RAILROAD STRUCTURES. 
 
 the nut is well tightened, a nail is driven in the slot or hole 
 with the head projecting far enough above the face of the 
 washer to permit of its being drawn with a claw hammer. 
 This effectually locks the nut. Wrought washers may be 
 effectually locked by nicking the thread with a center punch 
 after the nut has been screwed home. 
 
 Wrought washers, sometimes called punched, are also 
 used to a considerable extent in this class of structures. 
 They are circular in form, and are stamped out from sheet 
 iron, with a hole punched through the center of them. 
 
 Table 51 gives the dimensions of wrought washers, and 
 the number of each in a keg of 150 pounds: 
 
 TABLE 51. 
 
 S halving the Average Number of Wrought -Iron Washers in 
 a Keg of 150 pounds of each Standard Size, as Adopted by 
 the Association of Bolt and Nut Manufacturers of the 
 United States. 
 
 
 Size of 
 
 Thickness, 
 
 Size of 
 
 Number in 
 
 Diameter. 
 
 Hole. 
 
 Wire Gauge. 
 
 Bolt. 
 
 150 Pounds. 
 
 i 
 
 i 
 
 No. 18 
 
 3 
 
 80,000 
 
 1 , 
 
 • A 
 
 No. 16 
 
 i 
 
 34,285 
 
 1 
 
 A 
 
 No. 16 
 
 i 
 
 22,000 
 
 i 
 
 f 
 
 No. 16 
 
 5 
 
 18,500 
 
 1 
 
 7 
 
 No. 14 
 
 f 
 
 10,550 
 
 H 
 
 i 
 
 No. 14 
 
 1 
 
 7,500 
 
 If 
 
 A 
 
 No. 13 
 
 h 
 
 4,500 
 
 H 
 
 t 
 
 No. 12 
 
 A 
 
 3,850 
 
 If 
 
 H 
 
 No. 10 
 
 1 
 
 2,500 
 
 2 
 
 H 
 
 No. 10 
 
 i 
 
 1,600 
 
 H 
 
 il 
 
 No. 9 
 
 I 
 
 1,300 
 
 H 
 
 ItV 
 
 No. 9 
 
 1 
 
 950 
 
 2f 
 
 li 
 
 No. 9 
 
 li 
 
 700 
 
 3 
 
 If 
 
 No. 9 
 
 li 
 
 550 
 
 H 
 
 H 
 
 No. 9 
 
 If 
 
 450 
 
RAILROAD STRUCTURES. 1207 
 
 CONNECTIOlV WITH EMBANKMENT— PROTEC- 
 TION AGAINST ACCIDENTS. 
 
 1 775. Connection >vitli Embankment. — There ar, 
 two methods, in general use, of connecting a trestle with an 
 embankment, viz., by means of a bank crib, and by means 
 of a bank bent. In the former method the crib is usually 
 built of 12-in. by 12-in. square timbers halved one into the 
 other and drift-bolted at each intersection of the timbers. 
 There are several courses of timbers depending upon the 
 height of the embankment. The building of the crib should 
 be deferred until the rest of the trestle is completed, so as 
 to allow all possible time for the settlement of the embank- 
 ment. Before commencing the crib, a space of ample size 
 to receive it should be excavated from the end of the em- 
 bankment and the earth well rammed for a foundation be- 
 fore the timbers are put in place. The correct elevation for 
 this foundation should be determined by the engineers, so 
 that the top of the crib may have the proper elevation with- 
 out hewing away any of the timber. The timbers compo- 
 sing the front of the crib, i. e., the part facing the trestle, 
 should be at least 10 feet long, and those parallel to the 
 track of equal length. The top of the crib should be fixed 
 exactly at grade, so that trains may pass from the embank- 
 ment to the trestle, and vice versa, without any jolting. 
 Timbers frequently vary ^ inch in thickness, so that the 
 actual elevation of the top of the crib may vary 1 or 2 inches 
 from the calculated one. This discrepancy may be readily 
 remedied by shims, if the top of the crib is too low, 
 and by notching down the stringer, if the top is too 
 high. It is well to have the stringers extend back from 
 the face of the crib several feet. The bottoms of the 
 stringers should be kept from coming in contact with 
 the earth of the embankment. This may be prevented 
 by spiking planks to the crib timbers underneath the 
 stringers. The stringers should be drift-bolted to the 
 crib timbers. Such a connection between embankment 
 
1208 
 
 RAILROAD STRUCTURES. 
 
 and trestle as we have just described is shown in Fig. 
 017. 
 
 Fio. 617. 
 
 Connection between the embankment and the trestle 
 may be made by means of a bank bent, either of piles or 
 framed. This construction is more favored than the crib 
 form previously described. It consists of a strong frame or 
 pile bent built into the slope at the end of the embankment 
 for the support of the stringers. If piles are used, the bent 
 should contain four piles deeply driven into the embank- 
 ment, so that they will not only safely carry the train load, 
 but will sustain the pressure of the back filling, which is 
 
RAILROAD STRUCTURES. 
 
 120i> 
 
 carried up to the base of the stringers. To hold this piling 
 in place, the back of the bent is close planked with 3 -inch 
 or 4-inch plank. When the bank bent is of considerable 
 height, struts of 8-in. by 8-in. stuff should extend from 
 the bank bent to the timbers of the first trestle bent, to 
 insure its stability. When the bank bent is of framed tim- 
 ber, special pains should be taken to insure a safe founda- 
 
 FiG. 618. 
 
 tion for the sill. Sub-sills of 12-in. by 12-in. timber, laid 
 in trenches, form a good foundation. Before laying the 
 sub-sills, the ground should be thoroughly rammed to en- 
 sure against settlement. This construction is illustrated in 
 Fig. 618. 
 
 1776. Refuge Bays. — On all trestles of a length of 
 200 feet or more, refuge bays should be built where work- 
 men or track walkers can find safety when overtaken by a 
 train. They consist of small projecting platforms supported 
 by ties which are given 
 the additional length 
 
 4if 
 
 ^4-0^ 
 
 /3'a 
 
 '■J Space 
 
 iM 
 
 —4-9— 
 
 lf^4' 
 
 J 
 
 PS 
 
 necessary to include the 
 refuge bays. A refuge 
 bay of approved pat- 
 tern is shown in Fig. 
 619. On trestles of 
 
 a length exceeding fig. 6i9. 
 
 1,000 feet, every fourth refuge bay should be large enough 
 to contain a hand car and section gang. While repairs 
 are being made on a trestle, before work is commenced, 
 
 tnj 
 
1210 RAILROAD STRUCTURES. 
 
 the hand car, together with all idle tools, should be placed 
 in a refuge bay, and should remain there until the work is 
 finished. 
 
 1777. Foot Walks. — On some roads it is custom- 
 ary to place between the rails a foot walk of inch boards 
 from 1 to 2 feet in width. This is a mistake, in that 
 it encourages the public to use a trestle as a thorough- 
 fare on account of the ease in crossing it; it increases 
 the danger of fire, as the walk forms a lodgment for 
 coals dropped from the fire-boxes of the engines, and it 
 tends to careless inspection on account of the difficulty 
 of reaching the parts of the structure which are covered 
 by the walk. 
 
 1 778. Fire Protection. — Every trestle should be pro- 
 vided with the means of protection against fire. This is 
 sometimes effected by covering the tops of ties and string- 
 ers with sheet iron. A simpler and more effective protec- 
 tion is afforded by water stored in tubs at intervals of 
 not more than 200 feet, and provided either with buckets 
 or large dippers. The buckets should be of metal, wood 
 pulp, or paper. Metal well painted is preferable. The 
 track walker should examine all tubs at least once each 
 week and report their condition to the section foreman, 
 whose business it is to keep them full of water. Kero 
 sene barrels sawed in two make excellent tubs — cheap and 
 enduring. 
 
 An equally important safeguard against fire is the cutting 
 and burning of all grass and brush from the right of way 
 adjacent to the trestle, and the removal and burning of all 
 rubbish which could afford any lodgment for sparks. The 
 grass and brush should be cut early in the season, when the 
 stubble is too green to burn. 
 
 It is the contractor's business to protect the trestle against 
 fire during construction by the removal and burning of all 
 brush and rubbish which could in any way threaten its 
 safety. A clause to this effect should have a place in every 
 contract. 
 
RAILROAD STRUCTURES. 1211 
 
 FIELD ENGINEERING AND ERECTING. 
 
 1779. Locating Bents. — The number of bents com- 
 posing the trestle and the number of the station at the 
 beginning and end of the same are determined from an in- 
 spection of the profile. The center line of the trestle is then 
 run in, a plug being driven on the center line locating each 
 bent. It is customary to place these center plugs 1 foot in 
 advance of the bent centers so that they will not be dis- 
 turbed while placing the bents in position. The center 
 plugs being driven, the transit is set up at each plug and 
 stakes set at right angles to the center line, giving the direc- 
 tion of the sill. These stakes are, like the center plug, 
 1 foot in advance of the required center line of the sill. In 
 case the trestle is built on a curve, the bents should stand 
 on radial lines. 
 
 It is of the first importance that the levels be correct, 
 and to facilitate the checking of them, a bench mark with 
 an elevation of about the grade of the rail should be estab- 
 lished at the end of the trestle, and another near the lowest 
 point of the line over which the trestle passes. At each 
 center plug a strong stake should be driven, with the top of 
 the stake at the level of the top of the foundation for that 
 bent. One grade stake at each bent is sufficient, as the work- 
 men can transfer that elevation to other points, if necessary, 
 with an ordinary carpenter's or mason's level. 
 
 1780. Erecting. — Trestle bents of moderate height 
 are framed, lying flat on the ground, with the sills so placed 
 that when the bent is raised it will occupy its proper posi- 
 tion. The raising is effected by means of blocks and a fall, 
 the power being ordinarily applied by either horses or a 
 gang of men. The end bent is first raised and braced in 
 position, and the tackle for raising the next bent attached 
 to it. Stay ropes should be attached to a bent before it is 
 raised, to steady it and to prevent it from being pulled over 
 after it has reached an upright position. As soon as a bent 
 is raised, it should at once be fastened in position by means 
 of stay lath nailed to it and the bent immediately 
 
1212 RAILROAD STRUCTURES. 
 
 preceding. The sway-bracing should be fastened immedi- 
 ately, and when no longitudinal bracing is to be added, the 
 stringers should be put in place and fastened before raising 
 another bent. 
 
 High trestles, composed of several sections placed one 
 above the other, and separated by purlins (see Fig. 627), 
 are usually erected as follows: The bottom deck having been 
 raised, the purlins are placed upon it, and a temporary floor 
 laid on the purlins, upon which the bent forming the next 
 section is placed and raised precisely as though it lay on 
 the ground. 
 
 Special designs require special methods, but the plan 
 generally adopted is that given above. A tack or nail is 
 driven in each cap on the center line for the accurate pla- 
 cing of the stringers. After the ties and guard-rails are in 
 place and fastened, tacks are driven in ties at intervals of 
 about 50 feet, to guide the track layers. 
 
 1781. Preservation of Joints. — At every point 
 where two pieces of timber come in contact, they should be 
 painted with some preservative material. As trestle timbers 
 are usually rough, a considerable quantity of material is 
 necessary, if all joints are to be properly treated ; white lead, 
 though effective, is too expensive. Hot coal tar is a cheap 
 and effective wood antiseptic, and available everywhere. 
 Creosote oil is also much used, and when the finances of the 
 company admit of it, a trestle built of timber which has 
 been thoroughly treated with creosote oil under pressure is 
 undoubted economy. 
 
 1782. Trestle Specifications. — There is no class of 
 structures of the importance of wooden trestles upon which 
 there has been so gross neglect in the matter of specifica- 
 tions. Many important contracts contain but a few lines, 
 while others of equal importance carry specifications purely 
 general in character, in which many points of the first im- 
 portance are entirely neglected. The following specifica- 
 tions are general, but are sufficiently detailed to guide the 
 student in making an application to a particular structure: 
 
RAILROAD STRUCTURES. 1213 
 
 STANDARD SPECIFICATIONS FOR \VOODEN 
 TRESTLES. 
 
 CLEARING. 
 
 Before commencing work on any structure, the ground 
 must be entirely cleared of logs, stumps, trees, and brush of 
 every description. All combustible material must be piled 
 at convenient places and completely burned. Trees outside 
 the right of way which, by falling, may endanger the tres- 
 tle, must be felled by the contractor, it being understood 
 that permission to fell such trees shall be obtained by the 
 railroad company from the land owner. Such portions of 
 the right of way as shall be deemed necessary by the 
 engineer shall be grubbed. 
 
 DRAWINGS. 
 
 The drawings are to the scale indicated and marked; but 
 in all cases the figures are to be taken, and in case of omis- 
 sion the engineer in charge is to be referred to for dimen- 
 sions. Under no circumstances are the drawings to be 
 scaled either by the contractor or by any of his men. The 
 engineer will be required to mark the dimensions upon the 
 contractor's blue-print and to keep a record of the same in 
 his office. 
 
 DIMENSIONS. 
 
 All posts, braces, clamps, stringers, packing-blocks, ties, 
 guard-timbers, sills, and all timber generally, will be of the 
 exact dimensions given and figured upon the plan. Varia- 
 tions from these will be allowed only upon the written 
 consent of the engineer in charge. 
 
 TIMBER. 
 
 All timber shall be of good quality and of such kinds as 
 the engineer shall direct, and be free from wind-shakes, 
 black, loose, or unsound knots, worm holes, and all descrip- 
 tions of decay. It must be sawed true and out of wind, and 
 
1214 RAILROAD STRUCTURES. 
 
 full size. Under no circumstances will any timber cut from 
 dead logs be allowed to be placed in any part of the struc- 
 ture; it must in every case be cut from living trees. 
 
 PILES. 
 
 Piles shall be cut from live, thrifty timber. They will 
 be either round or square, as may be required by the engineer. 
 Roimd piles must be straight, be stripped of all bark, and be 
 well trimmed. They must be at least twelve (12) inches in 
 diameter at the cut-off, when cut to grade to receive the 
 cap. The smaller end must be at least eight (8) inches in 
 diameter. 
 
 Square piles must be hewn (or sawed) twelve (12) inches 
 square. They must have at least nine (9) inches of heart 
 wood on each face from the head of the pile after being cut 
 off to grade, to five (5) feet below the surface of the ground 
 into which the pile is driven. 
 
 All piles must be properly pointed. They shall, if re- 
 quired, be shod with shoes of cast or wrought iron, made 
 according to plans furnished by the engineer. In driving 
 they shall be banded with wrought-iron rings of suitable 
 weight to prevent splitting. The actual cost, delivered on 
 the ground, of the necessary shoes and rings will be allowed to 
 the contractor. Piles must be driven to hard bottom or 
 until they do not sink more than five (5) inches under the last 
 five (5) blows from a hammer of at least two thousand (2,000) 
 pounds weight, falling free twenty-five (25) feet. All piles 
 injured in driving, or driven out of place, shall be either 
 withdrawn or cut off, as the engineer may elect, and others 
 driven in their stead. The piles thus replaced will not be 
 paid for. All piles under track stringers must be accurately 
 spaced and driven vertically, and in each bent the batter 
 piles will be driven at the angle shown. 
 
 Piles shall be measured by the lineal foot after they are 
 driven and cut off, and the price per lineal foot shall be 
 understood to cover the cost of transportation, removing 
 the bark, driving, cutting off, and all labor and materials 
 required in the performance of the work, but that portion of 
 
RAILROAD STRUCTURES. 1215 
 
 each pile cut off shall be estimated and paid for by the lineal 
 foot as "piles cut off." 
 
 The contractor must give all facilities in his power to aid 
 the pile recorder in his duties. 
 
 Parts of pile heads projecting beyond the cap must be 
 adzed off at an angle of 45°. 
 
 FRAMING. 
 
 All framing must be done to a close fit and in a thorough 
 and workmanlike manner. No blocking or shimming of any 
 kind will be allowed in making joints, nor will open joints 
 be accepted. 
 
 All joints, ends of posts, piles, etc., and all surfaces of 
 wood on wood shall be thoroughly painted with 
 *hot creosote oil and covered with a coat of thick 
 asphaltum; 
 hot asphaltum; 
 hot common tar; 
 
 a good, thick coat of white lead ground and mixed with 
 pure linseed oil. 
 All bolt and other holes bored in any part of the work 
 must be thoroughly saturated with 
 *hot creosote oil; 
 hot asphaltum; 
 hot tar; 
 coal tar; 
 
 white lead mixed with pure linseed oil; 
 linseed oil. 
 
 And all bolts and drift bolts before being put in place 
 must be 
 
 ♦warmed and coated with hot creosote oil; 
 warmed and coated with hot asphaltum ; 
 warmed and coated with hot tar; 
 warmed and coated with hot coal tar ; 
 coated with coal tar; 
 coa'ted with white lead and linseed oil. 
 
 Optional methods of treatment. 
 
121G RAILROAD STRUCTURES. 
 
 All bolt holes for bolts three-quarters (|) of an inch in 
 diameter or over must be bored with an auger one-eighth 
 (^) of an inch smaller in diameter than the holt, in order to 
 secure a perfectly tight fit of the bolt in the hole. For bolts 
 five-eighths (|) of an inch in diameter, or smaller, the auger 
 must be one-sixteenth {j\) of an inch smaller, for the same 
 reason. 
 
 TRESTLES ON CURVES. 
 
 Trestles built on curves will have the outer rail elevated 
 according to plans furnished from the Chief Engineer's 
 office, a copy of which will be delivered to the contractor. 
 
 CREOSOTED TRESTLES. 
 
 All piles used in creosoted trestles must be completely 
 stripped of bark, and be pointed before treatment. None 
 of the sap wood may be hewn from the piles. No notching 
 or cutting of the piles will be allowed after treatment, ex- 
 cept the sawing off of the head of the pile to the proper 
 level for the reception of the cap, and the beveling of such 
 part of the head as shall project from under the cap. 
 
 The heads of all creosoted piles, after the necessary cut- 
 ting and trimming has been done for the reception of the 
 cap, must be saturated with hot creosote oil, and then cov- 
 ered with hot asphaltum before putting the cap in place. 
 
 Timber for creosoted trestles must be cut and framed to 
 the proper dimensions before treatment. No cutting or 
 trimming of any kind will be allowed after treatment, 
 except the boring of the necessary bolt holes. 
 
 Hot creosote oil must be poured into the bolt holes before 
 the insertion of the bolts, in such a manner that the entire 
 surface of the holes shall receive a coating of creosote oil. 
 
 TREATMENT OF CREOSOTED PILES AND TIMBER. 
 
 All creosoted timber and piles shall be. prepared in 
 accordance with the following process: The timber and 
 piles, after having been cut and trimmed to the proper 
 
RAILROAD STRUCTURES. 1217 
 
 length, size, and shape, shall be submitted to a contact 
 steaming inside the injection cylinders, which shall last 
 from two to three hours, according to the size of the tim- 
 ber; then, to a heat not to exceed 230° F., in a vacuum of 
 twenty-four (24) inches of mercury, for a period long enough 
 to thoroughly dry the wood. The creosote oil, heated to a 
 temperature of about 175°, shall then be let into the injec- 
 tion cylinder and forced into the wood under a pressure of 
 150 pounds per square inch, until not less than 15 pounds of 
 oil to the cubic foot has been absorbed. The oil must con- 
 tain at least 10 per cent, of carbolic and cresylic acids, and 
 have at least 12 per cent, of naphthalene. 
 
 IRON. 
 
 Wrought Iron. — All wrought iron must be of the best 
 quality of American refined iron, tough, ductile, uniform in 
 quality, and must have an elastic limit of not less than 
 twenty-six thousand (26,000) pounds per square inch. 
 
 All bolts must be perfect in every respect, and have nuts 
 and thread of the full standard size due their diameters. 
 The thickness of the nut shall not be less than the diameter 
 of the bolt, and the side of its square not less than twice 
 the diameter of the bolt. 
 
 The heads of all bolts shall be square ; round button ; 
 countersunk; 
 
 When square the thickness shall not be less than the diam- 
 eter of the bolt, and the side of its square not less 
 than twice the diameter of the bolt ; 
 When round button the thickness at center shall not be less 
 than three-quarters of the diameter of the bolt, and 
 the extreme diameter not less than two and one-half 
 times the diameter of the bolt; 
 When countersunk the extreme diameter of head shall not 
 be less than twice the diameter of the bolt, and 
 countersunk on the under side so as to fit into a cup 
 washer. 
 Cast Iron. — All castings must be of good, tough metal, 
 of a quality capable of bearing a weight of five hundred and 
 
1218 RAILROAD STRUCTURES. 
 
 fifty (550) pounds, suspended at the center of a bar one (1) 
 inch square, and four and one-half (4^) feet between sup- 
 ports. They must be smooth, well shaped, free from air 
 holes, cracks, cinders, and other imperfections. 
 
 All iron before leaving the shop must be thoroughly 
 soaked in boiled linseed oil. 
 
 INSPECTION AND ACCEPTANCE. 
 
 All materials will be subject to the inspection and accept- 
 ance of the engineer before being used. The contractor 
 must give all proper facilities for making such inspection 
 thorough. 
 
 Any omission by the engineer to disapprove the work at 
 the time of a monthly or any other estimate being made, 
 shall not be construed as an acceptance of any defective 
 work. 
 
 PROTECTION AGAINST FIRE. 
 
 The contractor must, each evening, before quitting work, 
 remove all shavings, borings, and scraps of wood from the 
 deck of the trestle and from proximity to the bents, and 
 upon the completion of the work must take down and re- 
 move to a safe distance all staging used in the erection of 
 the work, and remove and burn all fragments of timber, 
 shavings, etc. 
 
 ROADS AND HIGHWAYS. 
 
 Commodious passing places for all public and private 
 roads shall be maintained in good condition by the con- 
 tractor, and he shall open and maintain thereafter a good 
 and safe road for passage on horseback along the whole 
 length of his work. 
 
 RUNNING OP TRAINS. 
 
 The contractor shall so conduct all his operations as not 
 to impede the running of trains or the operation of the 
 road. He will be responsible to the railroad company for 
 
RAILROAD STRUCTURES. 1219 
 
 all injuries to rolling stock or damages from wrecks caused 
 by his negligence. The cost of such damage will be re- 
 tained from his monthly and final estimates. 
 
 RISKS. 
 
 The contractor shall assume all risks from floods, storms, 
 and casualties of every description, except those caused by 
 the railroad company, until the final estimate of the work. 
 
 LABOR AND MATERIAL. 
 
 The contractor must furnish all labor and material inci- 
 dental to or in any way connected with the manufacture, 
 transportation, erection, and maintenance of the structure 
 until its final acceptance. 
 
 Disorderly, quarrelsome, or incompetent men in the employ 
 of the contractor, or those who persist in doing bad work in 
 disregard of these specifications, must be discharged by the 
 contractor when requested to do so by the engineer. 
 
 Whenever the chief engineer may deem it advisable, he 
 may name the rates and prices to be paid by the contractors, 
 for such time as he may designate, to the several classes of 
 laborers and mechanics in their employ, and for the hire of 
 horses, mules, teams, etc., and these shall not be exceeded; 
 and having given due notice to the contractors of his action 
 in regard to these matters, they shall be boirwfl to "obey his 
 orders in relation thereto. The chief engineer shall not, 
 however, name a rate or price for any class of labor, etc., 
 higher than the maximum rates being paid by the contractor 
 paying the highest for that class. 
 
 INTOXICATING LIQUORS. 
 
 Contractors will not themselves, nor by their agents, give 
 or sell any intoxicating liquors to their workmen or to any 
 persons at or near the line of the railway, nor allow any 
 to be brought on the works by the laborers or any other 
 person, and will do all in their power to prevent their use in 
 the vicinity of the work by persons in their employ. A 
 
1220 RAILROAD STRUCTURES. 
 
 continued disregard for this clause will, if deemed necessary 
 by the engineer, be considered as a good and sufficient reason 
 for declaring the contract forfeited. 
 
 DAMAGES AND TRESPASS. 
 
 Contractors shall be liable for all damages to landholders, 
 arising from loss of or injury to crops or cattle, sustained 
 by any cause or thing connected with the works or through 
 any of their agents or workmen. They will not allow any 
 person in their employ to trespass upon the premises of per- 
 sons in the vicinity of the works, and will forthwith, at the 
 request of the engineer, discharge from their employ any 
 person that may be guilty of committing damage in this 
 respect. They will also maintain any fences that may be 
 necessary for the proper protection of any property or 
 crops. 
 
 REMOVAL OF DEFECTIVE ^VORK. 
 
 The contractor will remove at his own expense any ma- 
 terial disapproved by the engineer, and will remove and 
 rebuild, without extra charge, and within such time as may 
 be fixed by the engineer, any work appearing to the engin- 
 eer, during the progress of the work or after the comple- 
 tion, to be unsound, or improperly executed, notwithstand- 
 ing that any certificate may have been issued as due for the 
 execution of the same. The engineer shall, however, give 
 notice of defective work to the contractor as soon as he 
 shall have become cognizant of the same. On default of 
 the contractor to replace the work as directed by the engin- 
 eer, such work may be done by the railroad company at the 
 contractor's expense. 
 
 DELAYS. 
 
 No charge shall be made by the contractor for hin- 
 drances and delay, from any cause, in the progress of the 
 work; but it may entitle him to an extension of the time 
 allowed for completing the work, sufficient to compensate 
 
RAILROAD STRUCTURES. 1221 
 
 for the detention, to be determined by the engineer, pro- 
 vided he shall give the engineer in charge immediate notice, 
 in writing, of the detention. 
 
 EXTRA WORK. 
 
 No claim shall be allowed for extra work, unless done in 
 pursuance of a written order from the engineer, and unless 
 the claim is made at the first estimate after the work is ex- 
 ecuted. The chief engineer may, at his discretion, allow 
 any claim, or such part of it as he may deem just and 
 equitable. 
 
 Unless a price is specified in the contract for the class of 
 work performed, extra work will be paid for at the actual 
 cost of the material remaining in the structure after its 
 completion and the cost of the labor for executing the work 
 plus fifteen (15) per cent, of the total cost. This fifteen 
 (15) per cent, will be understood to include the use and cost 
 of all tools and temporary structures, staging, etc., and the 
 contractor's profit, and no extra allowance over and above 
 this will be made. 
 
 INFORMATIOIV AND FORCE ACCOUNTS. 
 
 The contractor will aid the engineer in every way possible 
 in obtaining information, and freely furnish any which he 
 may possess, by access to his books and accounts, in regard 
 to the cost of work, labor, time, material, force account, 
 and such other items as the engineer may require for the 
 proper execution of his work, and shall make such reports to 
 him from time to time as he may deem necessary and 
 expedient. 
 
 PROSECUTION OF THE WORK. 
 
 The contractor shall commence his work at such points as 
 the engineer may direct, and shall conform to his directions 
 as to the order of time in which the different parts of the 
 work shall be done, as well as the force required to complete 
 the work at the time specified in the contract. In case the 
 contractor shall refuse or neglect to obey the orders of the 
 engineer in the above respects, then the engineer shall have 
 
1222 RAILROAD STRUCTURES. 
 
 the power to either declare the contract null and void and 
 relet the work, or to hire such force and buy such tools at 
 the contractor's expense as may be necessary for the proper 
 conduct of the work, as may, in his judgment be for the best 
 interests of the railroad company. 
 
 CHANGES. 
 
 At any time during the execution or before the commence- 
 ment of the work, the engineer shall be at liberty to make 
 such changes as he may deem necessary, whether the quan- 
 tities are increased or diminished by such changes, and the 
 contractor shall not be entitled to any claim on account of 
 such changes beyond the actual amount of work done ac- 
 cording to these specifications at the prices stipulated in the 
 contract, unless such work is made more expensive to him, 
 when such rates as may be deemed just and equitable by the 
 chief engineer will be allowed him ; if, on the other hand, 
 the work is made less expensive, a corresponding deduction 
 may be made. 
 
 QUANTITIES. 
 
 It is distinctly understood that the quantities of work es- 
 timated are approximate, and the railroad company reserves 
 the right of having built only such kinds and quantities, and 
 according to such plans, as the nature or economy of the 
 work may, in the. opinion of the engineer, require. 
 
 ENGINEER. 
 
 The term engineer will be understood to mean the chief 
 engineer, or any of his authorized assistants or inspectors, 
 and all directions given by them, under his authority, shall 
 be fully and implicitly followed, carried out, and obeyed by 
 the contractor and his agents and employes. 
 
 PRICE ANI> PAYMENT. 
 
 The prices bid will include the furnishing of materials, 
 tools, scaffolding, watching, and all other items of expense 
 in any way connected with the execution and maintenance 
 
RAILROAD STRUCTURES. 1223 
 
 of the work until it is finally accepted and received as com- 
 pleted. The contractor will be paid only for the piles, tim- 
 ber, and iron left in the structure after completion. No 
 wastage in any kind of material will be paid for except in the 
 case of piles, when the " piles cut off," which can not be used 
 on any other part of the contractor's work, will be paid for 
 at the rate agreed upon. After the material cut off is 
 paid for, it is to be considered the property of the railroad 
 company, and is to be neither removed nor used by the con- 
 tractor without the consent of the engineer, and then only 
 upon the repayment of the price which has been paid 
 for it. 
 
 The piles and "piles cut oft" will be paid for by the lineal 
 foot, the former driven in place. 
 
 The timber and lumber remaining in and necessary to the 
 completed structure will be paid for by the thousand feet, 
 board measure. 
 
 The iron will be paid for by the pound, and only that 
 remaining in the structure after its completion. 
 
 The masonry for foundations will be paid for by the cubic 
 yard. 
 
 The excavations for foundations will be paid for by the 
 cubic yard. 
 
 The retained percentage will not be paid on the cost of 
 any single structure until the final estimate is due on the 
 entire work embraced in the contract. 
 
 When the trestling and grading are let under one con- 
 tract, or when a general contract, as by the miU\ includes 
 a considerable portion or all of a line, many of the 
 preceding clauses will be omitted in the section of the con- 
 tract pertaining to trestles, as they are general require- 
 ments applicable to all classes of work embraced by the 
 contract. Special conditions obtaining in a particular 
 section of the country may also require modifications of 
 some of the given clauses. The specifications given are 
 general and are intended to meet all certain requirements 
 and secure justice to both the contractor and the railroad 
 company. 
 
1224 
 
 RAILROAD STRUCTURES. 
 
 BILLS OF MATERIAL, RECORDS, AND 
 MAINTENANCE. 
 1783. Proper Forms. — Proper forms of bills of ma- 
 terial are of great importance to both contractor and en- 
 gineer: to the former in ordering and placing material, and 
 to the latter in checking, estimating, and keeping records of 
 the same. Few young engineers have any knowledge of 
 such forms, and many engineers of experience have been con- 
 tent with slovenly cut-and-try methods. The following is 
 a proper form of bill of material: 
 
 TRESTLE NO. 2. 
 
 DIVISION NO. 4. 
 
 RESIDENCY NO. 3. 
 
 BILL OF IRON. 
 
 No. of 
 Pieces. 
 
 Name. 
 
 Use. 
 
 Size. 
 
 Weight. 
 
 
 
 WROUGHT IRON. 
 
 
 
 24 
 
 Drift-bolts 
 
 Stringers to bank sills 
 
 i" sq. X 24' 
 
 
 26 
 
 Drift-bolts 
 
 Stringers to caps. . . . 
 
 f ' sq. X 24' 
 
 
 6 
 
 Drift-bolts 
 
 Sills to mud-sills. . . . 
 
 r sq. X 20' 
 
 
 102 
 
 Boat spikes 
 
 Ties to stringers .... 
 
 Yxir 
 
 
 150 
 
 Boat spikes 
 
 Guard-rails to ties. . . 
 
 VxW 
 
 
 26 
 
 Bolts 
 
 Guard-rails to jack- 
 stringers 
 
 rx31i' 
 
 
 12 
 
 Bolts 
 
 Caps to posts 
 
 rx22' 
 
 
 16 
 
 Bolts 
 
 Sway-bracing 
 
 |'X20' 
 
 
 32 
 
 Bolts 
 
 To 
 
 Packing for stringers 
 tal 
 
 f'x22' 
 
 
 
 CAST IRON. 
 
 
 172 
 
 Washers. . . 
 
 Under heads and nuts 
 
 
 
 
 Separators 
 
 of bolts 
 
 rx3' 
 
 2''X3' 
 
 
 32 
 
 Between stringers. . . 
 
 
 
 To 
 
 tal 
 
 
 
 
 
 
 All bills of material should be copied in a letter book. In 
 making out bills of material, the contractor should be al- 
 lowed the full length of each stick, including the tenon, 
 
RAILROAD STRUCTURES. 
 
 1225 
 
 pa 
 
 fa 
 o 
 
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 S3 
 
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 xxxxx xxxxxx xxxxxx xxxxx 
 
 
 N 
 
 «Kft££ £'t«t£ £t~t£- fcttKa 
 
 
 1 
 
 « *J 0> ■?» « *> Ci OJ « O OJ Ci -?> « « O Ci « » « 00 OO 
 
 xxxxx xxxxxx xxxxxx xxxxx 
 
 eoffjwoio* bc»wo*ice« boJOi©jec« ojoooobco 
 
 
 
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 en cfl cn^ -Q 
 
 
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 V 0) V tn 
 
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 4) « « sL 
 
 «4-i *«-4 *4-i rr> 
 
 "rt 
 
 £ 
 
 -^ - «^ ^ CO 
 A 00 
 
 
 
 S-* 
 
 J-l Tl U 
 
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 .O»<NOJ'-i00 .O*(N(Mi-iiN00 .C10»«t-(<NQ0 000O-*»-<0» 
 
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 4) a> V 
 
 
 
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 E,S 
 
 rH eo 00 
 
 
 S50 
 
 
 
122G RAILROAD STRUCTURES. 
 
 and where the tenon is cut on a skew, as in batter posts, 
 etc., the full size for the extreme length of stick should be 
 reckoned. 
 
 1 784. The number of feet B. M. (board measure) in a 
 stick of timber or in lumber 1 inch or over in thickness is 
 found by the following rule: 
 
 Mtiltiply together the breadth and thickness in inehes and 
 the length of the stick in feet, and divide the product by 12. 
 The quotient will be the number of feet required. 
 
 If we denote the breadth by b, the thickness by /, and the 
 length by Z, we may put the question in algebraic form as 
 
 f°"°*^ ■■ Feet B. M. = *-H^. ( 1 26.) 
 
 When lumber is less than 1 inch in thickness, it is always 
 reckoned as though it were a full inch thick. 
 
 A table like the following, containing the number of feet 
 B. M. in each piece entering into the standard trestle will 
 greatly facilitate the making out of bills of material: 
 
 General. — Each trestle will require: 
 
 8 Bank sills, 12' X 12' X 12' 0' 1,152 ft., B. M. 
 
 4 Dump boards, 4' X 8' X 11' 4' 121 ft., B. M. 
 
 Stringer pieces, 8' X 16' X 25' 0' contain each 267 ft., B. M. 
 
 Ties, 6' X 8' X 12' 0' contain each 48 ft. , B. M. 
 
 Guard-rails, 6' X 8' X 20' 0' contain each 80 ft., B. M. 
 
 1785. Inspection. — After the road is completed and 
 turned over to the operating and maintenance depart- 
 ments, the trestles, as well as all other structures forming a 
 part of the roadway, should be regularly and thoroughly in- 
 spected. At least once every year, at a favorable season, 
 the work of inspection should be performed by the en- 
 gineer in charge of the maintenance-of-way department. The 
 inspection should be thorough in every detail, and where the 
 traffic is heavy, this inspection should be made twice a year. 
 
 Once each month all structures should receive a careful 
 examination by a competent inspector. Not only the deck 
 timbers, but all timbers entering into the structure, should 
 be examined, and every necessary help should be afforded 
 
RAILROAD STRUCTURES. 
 
 1227 
 
 the inspector to facilitate his work. He should make out a 
 complete report on proper blanks of the condition of each 
 structure, forwarding them to either the division engineer 
 or division superintendent, who, having examined and ap- 
 proved the reports, forwards them to the engineer of main- 
 tenance of way. 
 
 A further inspection should be made by the track walker^ 
 and that as often as he crosses the bridge or trestle, though 
 it be several times a day. Of course, the inspection of the 
 latter will consist only of a general oversight, but sufficient 
 to detect at once any exterior defect or lack. The track 
 walker will be provided with blanks for making out reports. 
 The following form is suitable for his report: 
 
 BLACK RIVER VALLEY RAILROAD. 
 
 TRACK l^VALKEH'S DAILY REPORT 0!V THE CONDITION 
 OF BRIDGES AND TRESTLES. 
 
 Number of 
 
 Time. 
 
 Condition. 
 
 Bridge. 
 
 A. M. 
 
 P. M. 
 
 A. M. 
 
 p. M. 
 
 M. P. 123 A 
 
 7:45 
 
 5:45 
 
 X 
 
 X 
 
 M. P. 123 B 
 
 8:10- 
 
 5:20 
 
 X 
 
 X 
 
 M. P. 124 A 
 
 8:30 
 
 4:50 
 
 X 
 
 X 
 
 M. P. 124 B 
 
 9:00 
 
 4:20 
 
 X 
 
 X 
 
 M. P. 124 C 
 
 9:50 
 
 3:50 
 
 X 
 
 X 
 
 M. P. 125 A 
 
 10:30 
 
 3:30 
 
 X 
 
 X 
 
 M. P. 125 B 
 
 10:50 
 
 3:00 
 
 X 
 
 X 
 
 M. P. 126 A 
 
 11:20 
 
 2:30 
 
 X 
 
 X 
 
 M. P. 126 B 
 
 11:45 
 
 1:40 
 
 X 
 
 X 
 
 M. P. 126 C 
 
 12:00 
 
 1:10 
 
 X 
 
 X 
 
 Track Walker. 
 
 .189. 
 
 These blanks are bound in pads of fifty sheets and carry 
 a pasteboard cover for protection. When filled out the re- 
 port is folded and endorsed on the back : 
 
1228 RAILROAD STRUCTURES. 
 
 BLACK RIVRR VALLEY RAILROAD. 
 
 Track Walker s Daily Report. 
 Bridges and Trestles from *M. P. 123 A to M. P. 126 C. 
 In the report, X in the column headed Condition, means 
 "all right;" O means " injured or unsafe," by fire, washout, 
 or from other cause. In case of danger, the fact must be 
 reported by telegraph from the nearest station to the in- 
 spector of bridges, the division engineer, and the division 
 superintendent. 
 
 1 786. Inspector's Tools and Their Use. — An ax 
 
 or hatchet and small auger are the essential part of an 
 inspector's outfit. Decay generally commences at the sur- 
 face of timber, and is at once manifest. On the other 
 hand, dry rot, or powder post, as it is vulgarly termed, com- 
 mences beneath the surface, and it frequently happens that 
 a piece of timber, which from the surface appears perfectly 
 sound, is totally decayed inside, leaving only a shell of sound 
 timber. Where this form of decay is in an advanced stage, 
 it may be detected by striking a few blows upon the surface 
 of the timber, which will give a hollow sound ; but where the 
 shell is thick, the defect may be revealed by boring a small 
 hole into the timber, the degree of ease with which the hole 
 is bored determining the degree of -soundness of the timber. 
 The simplest, and an excellent way as well, of testing tim- 
 ber is by driving a slim wire nail or spike into the wood; the 
 soundness of the timber in this case, as in boring, will be 
 revealed by the ease or difficulty in driving the nail. 
 Whenever a hole is bored, it should be plugged as soon as it 
 has served its purpose, and but few holes should be bored 
 in the same stick. 
 
 Piles in trestles need not be examined for decay until they 
 have been several years in the ground ; but whenever there 
 is any suspicion of decay, an examination should be made at 
 once. Decay first attacks the piles at or near the surface of 
 the ground, and, in order to examine them, the earth must 
 be removed to the depth of 1 foot, or more if necessary. A 
 short, sharp-pointed steel bar is a good tool for testing the 
 
 * Mile post. 
 
RAILROAD STRUCTURES. 
 
 1229 
 
 soundness of piles. After a pile has been examined, the 
 cavity made for the examination should be refilled and the 
 earth well tamped. 
 
 In every case where a serious defect is discovered, which 
 in any way threatens the safety of the structure, the inspector 
 should at once notify, by telegraph from the nearest station, 
 the division engineer and division superintendent of the 
 fact, stating as briefly and clearly as possible the nature and 
 extent of the defect or damage, 
 
 1 787. Bridge Numbers. — On most roads the bridges 
 and trestles are numbered consecutively, beginning at the 
 terminus of the road. A much better way, now being 
 introduced, is to number the bridges alphabetically, com- 
 mencing at each mile post (M. P.). Thus, bridge No. 96 A 
 means the first bridge after passing mile post 96, and at 
 once conveys to the mind a definite idea of location. On 
 the other hand, bridge No. 125, unless some other explana- 
 tory reference is given, is of small aid in locating a bridge. 
 Bridge numbers are usually painted in black figures three 
 inches in height on a white ground. 
 A l|-inch pine board of suitable width 
 is given four or five coats of white lead, 
 and the numbers painted upon it in 
 heavy distinct lines. The boards should 
 
 -6^ 
 
 J 
 
 On 
 GMurd'y 
 rail 
 
 H 
 
 ^^ 
 
 wv/A 
 
 Fig. 630. 
 
 Fig. 621. 
 
 be of uniform height, and uniformly placed. The first right- 
 hand cap of a trestle and the first right-hand tie of an open 
 culvert on passageway are suitable locations for bridge 
 numbers. Suitable forms of bridge numbers are shown in 
 Figs. 620 and 621. 
 
1230 
 
 RAILROAD STRUCTURES. 
 
 STANDARD TRESTLE PLANS. 
 
 1788. In this section, the purpose is to illustrate by 
 complete plans the various types of trestles in general use, 
 whose efficiency has been proved by long service. 
 
 STANDARD SIIVGLE-TR ACK PILE TRESTLE. 
 
 1789. In Fig. 622 is given apian of a pile trestle suit- 
 able for heights of from 6 to 20 feet. On roads with only a 
 
 moderate traffic, 
 bents of three piles 
 each may be safely 
 used for heights of 
 from to 10 feet, 
 but for all through 
 lines no trestle bent 
 should contain less 
 than four piles, 
 
 having at the cut-off point a diameter of not less than 
 12 inches, inside of bark measurement. 
 
 It is customary to notch down the caps 1 inch on the pile 
 heads. The main object for this notching is to hold the 
 piles in place while they are being drift-bolted, in case they 
 have been sprung in driving. The caps are drift-bolted to 
 the piles with f in. diam. X 24 in. drift-bolts, and the stringers 
 to the caps with drift-bolts of the same dimensions. The 
 ties are not fastened to the stringers, but notched down 
 
RAILROAD STRUCTURES. 1231 
 
 1 inch over the stringers, which prevents any lateral move- 
 ment. The guard-rails are so close to the rails that in case 
 of derailment the weight of the derailed engine or car will 
 bear almost directly upon the strrnger. This form of trestle 
 is simple and thoroughly efficient. 
 
 DIMENSIONS OF TIMBERS. 
 
 Floor System : 
 
 Guard-rails, 7 in. x 7 in. x 20 ft., notched 1 in. over ties. 
 Ties, 7 in. X 8 in. X 9 ft., notched 1 in. over stringers. 
 Stringers, 8 in. X 16 in. X 24 ft., sized over caps to 15 in. 
 Packing-blocks, 2 in. X 16 in. X -t ft., notched 3 in. over 
 caps. 
 Bents: Caps, 12 in. X 12 in. X 14 ft., notched 1 in. over 
 pile heads. 
 Piles, at least 12 in. in diameter at cut-off. 
 
 DIMENSIONS OF IRON DETAILS. 
 
 Bolts: -^ in. X 15^ in., guard-rails to ties. 
 
 f in. X 20^ in., through stringers at packing- 
 blocks. 
 
 Drift-bolts, f in. diam. X 24 in., stringers to caps and caps 
 to piles. 
 
 STANDARD FRAMED TRESTLE, PENNSYLVANIA 
 RAILROAD. 
 
 1 790. The standard single-track framed trestle, as 
 employed by the Pennsylvania Railroad, is shown in Fig. 
 623. Like all standard structures in use on this important 
 line, this trestle is a model structure, combining great 
 strength and simplicity of design. Its characteristic fea- 
 tures are in the arrangement of the posts, by which the 
 weight of the load is about equally divided between the 
 vertical and the batter posts, and in the longitudinal bra- 
 cing, shown in detail at A. It will be observed that only in 
 trestles exceeding a height of 20 feet are the posts given 
 dimensions so large as 12 in. X 12 in. in cross-section, and 
 then only in the vertical posts. On the other hand, the 
 stringer dimensions which are commonly adopted on other 
 lines are considerably exceeded in this trestle. For spans 
 
1232 
 
 RAILROAD STRUCTURES. 
 
 of 14 feet, two stringer pieces are required, each 10 in. x IT 
 
 r^r^ — qv — ^^^^ — c=l— r^l 
 
 Fig. 623. 
 
 in., and for spans of 16 feet three pieces, each 8 in. x 17 in. 
 This places the excess of timber, if any, where it is most 
 
RAILROAD STRUCTURES. 1233 
 
 likely to be needed. Many trestles are weak in the stringers, 
 especially those designed for light traffic. On account of 
 traffic interchange, these trestles are continually required 
 to carry loads for which they were not designed, and often 
 far beyond the point of safety. Numerous accidents have 
 occurred directly attributable to this cause. In designing 
 a trestle, due regard must be paid to this point. A little 
 extra timber in the stringers will not add greatly to the 
 cost of the structure, and will vastly increase its efficiency 
 and the reputation of the road. 
 
 Special attention is called to the ties, which are much 
 above the average in size of cross-section, though propor- 
 tionately below the average in length. The same is true 
 in the length of caps, which in trestles below 20 feet in 
 height are only 10 feet in length, and in those of greater 
 height only 12 feet in length, whereas 14 feet is the length 
 generally adopted. This is unquestionably saving timber 
 to good purpose. It is a mistake to space the guard-rail 
 more than 15 inches from the track rail, and 12 inches is 
 amply sufficient. The purpose of the guard-rail is to keep 
 the derailed engine or car upon the trestle, and the less the 
 space between the rail and the guard-timber, the less will 
 be the danger of the ties being broken off by sudden shock 
 and weight brought upon them. Where a wide space is left 
 between the rail and the guard timber, a jack-stringer is 
 indispensable, but it would seem a better policy to put the 
 extra timber forming the jack-stringers into the track 
 stringers, and with the extra length of tie make a shorter 
 tie with larger cross-section. Batter posts have a batter of 
 3 inches to the foot. Mortises and tenons for the smaller 
 posts are 3 in. x 5 in. X 7 in., and for the larger posts 
 3 in. X 5 in. X 8 in. 
 
 DIMENSIONS OF TIMBERS. 
 
 Floor System : 
 
 Guard-rails, 5 in. X 8 in., notched 1 in. over ties. 
 Ties, 7 in. X 10 in. X 9 ft., notched ^ in. to receive guard- 
 rails, and ^ in. over stringers. 
 
1234 RAILROAD STRUCTURES. 
 
 Stringers : 
 
 Clear Span. 
 
 Number of Pieces 
 Under Each Rail. 
 
 Width of Each 
 Piece. 
 
 Depth of 
 Stringers. 
 
 10 
 
 2 
 
 8 in. 
 
 15 in. 
 
 12 
 
 2 
 
 8 in. 
 
 16 in. 
 
 14 
 
 2 
 
 10 in. 
 
 17 in. 
 
 16 
 
 3 
 
 8 in. 
 
 17 in. 
 
 Packing-blocks, 2 in. x 18 in. x ft. 
 
 Bents under 20 ft. : Cap, 10 in. X 12 in. X 10 ft. 
 
 Plumb posts, 10 in. X 12 in. 
 
 Batter posts, 10 in. x 10 in. ; batter 3 in. to 1 ft. 
 
 Sill, 10 in. X 12 in. 
 
 Bents 20 ft. and over : Cap, 12 in. x 14 in. X 12 ft. 
 
 Plumb posts, 12 in. x 12 in. 
 
 Batter posts, 10 in. x 12 in. ; batter 3 in. to 1 ft. 
 
 Sill, 12 in. X 12 in. 
 
 Sway-bracing, 3 in. x 10 in. 
 
 Bracing : Longitudinal, 8 in. X 8 in. 
 
 Treenails : Locust, 1 in. in diameter. 
 
 DIMENSIONS OF IRON DETAILS. 
 
 Bolts: f in. X ; guard-rails to ties. 
 
 f in. X ; guard-rail joints. 
 
 f in. X ; stringer joints; packing-blocks. 
 
 f in. X ; sway-bracing to caps and sills; 
 
 3 in. wrought-iron washers used. 
 
 Drift-bolts (ragged): 1 in. X 24 in. ; stringers to caps. 
 
 Spikes : Boat, f in. x 9 in. ; guard-rails to ties. 
 
 ^ in. X 8 in. 
 Cut, X 
 
 Wrought-iron washers : 
 
 ; sway-braces to posts. 
 
 longitudinal braces to caps 
 and sills. 
 
 2^ in. square for J-in. bolt. 
 
 3 in. round for f-in. bolt. 
 
RAILROAD STRUCTURES. 
 
 1235 
 
 STANDARD FRAMED TRESTLE, CLEVELAND AND CANTON 
 
 RAILROAD. 
 
 1791. A style of trestle which is aptly called a com- 
 pound timber trestle, and growing much in favor, is 
 illustrated in Fig. 
 624. The character- 
 istic feature of this 
 type is that the main 
 members, such as 
 stringers, caps, posts, 
 sills, etc., are com- 
 posed of two or more 
 pieces bolted to- 
 gether. The princi- 
 pal ■ advantages of 
 this style of construc- 
 tion are in the re- 
 duction of the cost 
 of timber and in the 
 
 facility and safety with which repairs can be made. As 
 the parts are bolted together, a defective piece may be 
 
1236 RAILROAD STRUCTURES. 
 
 readily replaced, and that without endangering or delaying 
 traffic. In general, a better quality of timber may be had 
 in small dimensions than in large ones, and at much less 
 cost. As the pieces forming each member are separated 
 from each other, there is a complete circulation of air through- 
 out the structure, which seasons and preserves the timber. 
 
 The amount of iron in the structure is necessarily large, 
 but if it is well dipped in tar or asphaltum before being 
 placed in the structure, the iron should outlast two or three 
 wooden structures. This form of trestle is no more expen- 
 sive to build than a framed structure, and its popularity is 
 ample evidence of its general excellence. 
 
 DIMENSIONS OF TIMBERS. 
 
 Floor System : 
 
 Guard-rails, 8 in. x 8 in., notched 1 in. over ties. 
 Ties, 7 in. X 9 in. x 8 ft. 4 in. , notched 1 in. over stringers. 
 Stringers, 7 in. x 14 in. x 30 ft., notched 1 in. over capa 
 in. X 15 in. x 20 in. 
 
 i3ii 
 'M 3 ii 
 
 Brace blocks, , _ . _ . ^ . . 
 ' ( 3 m. x 15 m. X 34 m. 
 
 Bents : Caps, 6 in. x 12 in. X 12 ft. 
 All posts, 6 in. X 12 in. 
 Sills, 6 in. x 12 in. 
 Sway-braces, 3 in. x 10 in. 
 Tenon blocks, 3 in. X 12 in. X 3 ft. 
 
 Longitudinal Braces : Girts, 4 in. X 10 in. X 17 ft. 
 
 T.. , ( 6 in. X 8 in. 
 
 Diagonals, ] 3 ._^^ g ._^ 
 
 DIMENSIONS OP^ IRON DETAILS. 
 
 Bolts : f in. X 14 in. ; guard-rails to ties. 
 
 I in. X 26 in. ; stringer joints; packing-bolts. 
 I in. X 21 in. ; sway-braces to posts and at inter- 
 section of diagonal longitudinal braces. 
 I in. X 23 in. ; longitudinal girts to plumb posts. 
 I in. X 19 in. ; Iqngitudinal girts to batter posts. 
 I in. X 18 in. ; packing-bolts for posts. 
 f in. X 26 in. ; interior diagonal braces to posts. 
 
RAILROAD STRUCTURES. 
 
 1237 
 
 „j . j f in. X 3 in. 
 
 ( 1 in. X S^ in. 
 Separators : 2 in. X 3| in. 
 
 STANDARD FRAMED TRESTLE, OHIO COXNECTING 
 RAILWAY. 
 
 1792. In Fig. G25 we have the standard framed trestle 
 adopted by the Ohio Connecting Railway. For heights 
 under 30 feet, the bent consists of one deck, but for heights 
 
 Fig. 625. 
 above 30 feet two decks are employed, as shown in the 
 figure. As the middle posts are directly under the rails, 
 they carry a large share of the load, and to distribute this 
 load the counter posts a b and c d are employed. The inner 
 posts are given a batter of ^ inch to the foot, which helps 
 to distribute the load. The sub-sills are inexpensive, fairly 
 enduring, and easily renewed. The foundations should be 
 of masonry if the trestle is to be permanent, and if the- 
 situation does not admit of masonry, piles should be used. 
 
1238 RAILROAD STRUCTURES. 
 
 DIMENSIONS OF TIMBERS. 
 
 Floor System : 
 
 Guard-rails, 8 in. x 8 in. x20 ft., notched 1 in. over ties 
 Ties, 7 in. X 8 in. X 10 ft., notched 1 in. over stringers. 
 Stringers, 9 in. x 10 in. x 28 ft., notched 1 in. over caps. 
 Bents: Caps, -12 in. X 12 in. X 14 ft. 
 Posts, 12 in. X 12 in. 
 Counter posts, 10 in. x 12 in. 
 Sills, 12 in. X 12 in. 
 Sway-braces, 3 in. X 10 in. 
 Longitudinal Braces : Girts, 8 in. X 12 in. 
 
 DIMENSIONS OF IRON DETAILS. 
 
 Bolts : f in. X IG^ in. ; guard-rails to ties. 
 
 - . ' ,-,;.'[■ sway-braces to caps and sills, 
 f in. X 17^ in. ) -^ ^ 
 
 f in. X 22:J- in. ; purlins to posts. 
 
 f in. X 23 in. ; stringers to caps. 
 
 "Washers : f in. X 3 in. 
 
 STANDARD DOUBLE-TRACK PILE TRESTLE, BOSTON 
 AND ALBANY RAILROAD. 
 
 1793. A double-traclc trestle is nothing rnor* than 
 two single-track trestles so combined as to form one struc- 
 ture. In Fig. G2(!, we have the standard double-track pile 
 trestle as adopted by the Boston and Albany Railroad. 
 The two special features of this trestle to which the atten- 
 tion of the student is called are the use of split caps, shown 
 in detail at A, and the lateral bracing more distinctly shown 
 in the plan. The split caps, being but half the size of ordi- 
 nary caps, may be had in better timber at less cost, and may 
 be renewed without in any way interfering with traffic. The 
 smaller-sized timbers, on account of their thorough and 
 rapid seasoning, are less liable to suffer from dry rot, and 
 being of comparatively small weight, they are easily and 
 cheaply handled. It is a common practice, where split caps 
 are used, to make the tenons at the end of the pile G inches 
 in thickness. So great a thickness is unnecessary, and where 
 
RAILROAD STRUCTURES. 
 
 1239 
 
 the piles are under 14 inches in thickness the shoulder left 
 for the cap to rest upon is entirely too small. A tenon 3 
 
 inches in thickness is ample and insures a shoulder of ample 
 width. The stringer joint is shown in detail at B, The 
 stringers are not notched over the caps, but are sized with 
 
1240 RAILROAD STRUCTURES. 
 
 an adz to a uniform thickness. Large timbers are certain 
 to vary from ^ inch to \ inch in thickness; hence, the neces- 
 sity of sizing. The notching of the stringers would prevent 
 the removal of a cap unless the stringer was raised for the 
 purpose. 
 
 DIMENSIONS OF TIMBERS. 
 
 Floor System : 
 
 Guard-rails, 8 in. x 8 in., notched 1 in. over ties. 
 Ties, 7 in. X 8 in., notched 1 in. over stringers. 
 Stringers, 8 in. x 10 in. x 24 ft. 
 Bents: Caps, 6 in. X 12 in. X 24 ft. 
 Sway-braces, 3 in. X 10 in. 
 Piles, 12 in. in diameter. 
 Lateral Braces : 6 in. x 6 in. 
 
 DIMENSIONS OF IRON DETAILS. 
 
 Bolts: -^ in. X 10 in. ; splicing guard-rails. 
 
 f in. X 32 in. ; guard-rails to ties and stringers. 
 
 f in. X 20 in. ; through stringers at separators. 
 
 f in. X 18 in. ; caps to piles. 
 
 ^ in. X 14 in. ; at intersections of lateral braces. 
 Drift-bolts : f in. X 24 in. ; stringers to caps. 
 
 STANDARD FRAME TRESTLE, OREGON AND IVASHINGTON 
 
 RAILROAD. 
 
 1794. High trestles furnish opportunity for construct- 
 ive skill and judgment of a high order. Methods of con- 
 structing trestles of this class, as of others, have changed 
 much in recent years. More iron is introduced and less 
 framing. Posts and sills are fastened together with dowels 
 instead of with mortise and tenon; braces are fastened with 
 bolts, and, wherever possible, the cutting of timber incident 
 to framing is avoided. The braces are increased in size and 
 reduced in number. Instead of short braces framed into the 
 posts at each angle, long braces, reaching from one-half to 
 the total width of the bent, are bolted to the main tmibers. 
 By this means, the strains due either to the wind pressure or 
 the train load are distributed throughout the structure. 
 
RAILROAD STRUCTURES. 
 
 1241 
 
 The trestle shown in Fig. G27 is a copy of one built on the 
 line of the Oregon and Washington Railroad. Its height 
 from ground to rail is about 100 feet, and for simplicity and 
 
 Fig. 627. 
 
 strength of design it has no superior. By battering the 
 inside posts, the load is well distributed over the base, which 
 has sufficient breadth to insure stability. The system of 
 
1242 RAILROAD STRUCTURES. 
 
 sway-bracing is exceptionally good. The horizontal wales 
 a, b, and c, which are bolted to the posts, practically double 
 the number of decks and reduce the post lengths to one-half 
 their actual length. They also form seats for the purlins d, /, 
 and h. 
 
 Each bent consists of three sections of equal height, 
 separated by eight 12 in. X 12 in. purlins, r, g. These pur- 
 lins extend longitudinally the length of two bents, breaking 
 joints like stringers, and form decks upon which the succes- 
 sive sections rest. The purlins are notched down 1 inch on 
 the caps, and are also notched 1 inch to receive the sills of 
 the bent resting upon them. The caps and sills of succeed- 
 ing sections are bolted together. The purlins constitute 
 the entire longitudinal bracing, excepting in the upper 
 section, where diagonal braces k, I are employed. It 
 would add considerably to the stability of the structure if 
 similar braces were placed in every panet from the ground 
 upwards. The plan shows but one dowel at each connection 
 of post with sill. Two would be a better number, especially 
 in the case of the outside batter posts and the counter posts 
 7«, «, <7, and/. 
 
 DIMENSIONS OF TIMBERS. 
 
 Floor System : 
 
 Guard-rails, 10 in. x 12 in. and 5 in. x 8 in., notched 1 in. 
 
 over ties. 
 Ties, G in. x 8 in. x 16 ft., notched 1 in. over stringers. 
 Track stringers, 9 in. x IG in. x 32 ft., notched 1 in. over 
 
 caps. 
 Jack-stringers, 7 in. x IG in. X 32 ft. 
 Spreaders, 3 in. X 12 in. 
 
 Bents: Caps, 12 in. X 14 in. x 16 ft. 
 Plumb posts, 12 in. x 12 in. 
 Batter posts, 12 in. X 12 in. 
 Intermediate caps and sills, 12 in. x 14 in. 
 
 S^ray-Bracing : Horizontal, 6 in. X 10 in. 
 Diagonal, 6 in. x 10 in. 
 Main sill, 12 in. x 14 in. 
 
RAILROAD STRUCTURES. 1243 
 
 Longitudinal Bracing: Horizontal, in. X 10 in. 
 
 Diagonal, C in. X 10 in. 
 Purlins, 12 in. X 12 in. X 18 ft. 
 
 DIMENSIONS OF IRON DETAILS. 
 
 Bolts : f in. X 49 in. ; floor system to caps. 
 
 f in. X 41 in. ; sills to caps of different decks. 
 
 f in. X 37 in. ; outside guard-rails to jack-stringers 
 
 f in. X 27 in. i . -^ a- ^ u 
 
 : . ^,„ . I longitudinal bracing. 
 
 f in. X 24| in. f ^ ^ 
 
 f in. X 23 in. ; sway-brace splice, sill splice, hori- 
 zontal sway-bracing to posts. 
 
 f in. X 22 in. ; stringer joints, packing bolts. 
 
 f in. X 19 in. ; sway-braces to posts. 
 
 f in. X 11 in. ; inside guard-rails to ties. 
 Drift-bolts : f in. X 24 in. ; sills to piles and stringers to 
 \ caps. 
 
 Do-wels : 1 in. X 6 in. ; posts to caps and sills. 
 Spikes I Cut 60-penny ; spreaders and brace blocks to caps. 
 
 Boat, ^ in. X 9 in. ; sway .-braces to posts. 
 Cast Washers : Under head and nut of each bolt. 
 
 1795. Practical Suggestions. — In practically all 
 trestles on American roads, designs have, either intentionally 
 or otherwise, placed the stringers directly over the posts and 
 the rails directly over the stringers, so that the shock of the 
 passing train is communicated directly to the post through 
 the tie and stringer, and through the post to the hard, un- 
 yielding foundation. The effect of this can not be other 
 than to place unnecessary stress upon particular timbers, 
 and to subject both rolling stock and foundation to unneces- 
 sary shock. 
 
 In most trestles, whether pile or framed, the stringers are 
 placed directly above the inside posts or piles, which are 
 usually vertical, and, consequently, must take practically 
 all the load until from some cause or other these inside posts 
 or piles settle, and then, and not until then, is a part of the 
 load transferred through the cap to the outside posts or 
 
1244 
 
 RAILROAD STRUCTURES. 
 
 piles. It is evident that if the stringers were placed mid- 
 way between the posts or piles, the load would be practically 
 divided between them; and, as there would then be a short 
 distance from the stringer to each post, some of the shock, 
 at least, would be taken up by the cap. If, now, instead of 
 placing the stringer with its center directly under the rail, 
 it were moved say 6, 9, or 12 inches outwards from the 
 rail, the ties would act partly as beams, and a part of the 
 shock would be taken up by them. By arranging the posts 
 or piles as before suggested, a further portion of the shock 
 would be taken up by the cap. leaving a much smaller pro- 
 portion of- it to be transferred by the posts to the founda- 
 tion, and, through recoil, to the passing train. Now, if 
 
 Jlfbtch 
 
 1 "^'^ k^ 
 
 ijfotch 
 
 tie. 628. 
 
 under the present system the great share of the load is 
 carried (and, apparently, with safety) by the vertical posts, 
 would not an equal load be carried with equal safety by 
 
RAILROAD STRUCTURES. 1245 
 
 smaller timbers so arranged that each shall perform its full 
 proportion of work ? 
 
 In iron bridges the floor system is so arranged that the 
 ties shall act as beams, and there is no reason why the floor 
 system of a trestle bridge should not be arranged in the 
 same way. The only objection to moving the stringers 
 from under the rail is that in case of derailment the weight 
 of the derailed engine or car would, through the wheels, be 
 concentrated upon only a few ties. To obviate this danger, 
 or, at least, greatly reduce it, the ties should be placed near 
 together, with not more than G inches of clear space be- 
 tween them. This would practically form a solid floor, 
 upon which, the wheels would run without danger of biincJi- 
 ing the ties. The guard-rail should be not more than 12 
 inches from the rail, and should be not less than 7 in. x 8 
 in. in cross-section, notched 1 inch over the ties, and bolted 
 to at least every fourth tie. With such an arrangement of 
 parts, posts, caps, and sills 10 in. X 10 in. in cross-section 
 would meet every requirement. 
 
 1 796. A trestle plan embodying these ideas is given in 
 Fig. 628, and recommended to the student for practical 
 study and work. From the plan it will be seen that in case 
 of derailment, so long as the guard timbers hold, the out- 
 side wheels of the derailed trucks will bear directly upon the 
 stringer, which absolutely insures the ties against breaking. 
 The ties, being strongly supported at both ends, can not be 
 broken by the inside wheels of the derailed trucks, unless 
 they are weakened by decay. To prevent bunching, the 
 ties must, as stated above, be placed so close together that 
 derailed wheels will roll over them. The caps, posts, and 
 sills are considerably smaller than those used on most rail- 
 roads, special exception being made in the case of the Penn- 
 sylvania Railroad, already noted. The stringers, on the 
 other hand, are increased in section from 8 in. x 10 in., a 
 size widely adopted, to 9 in. X 16 in., and are amply strong 
 for spans of 14 feet. The guard-rails are also increased in 
 size above that generally employed. The caps and sills 
 
124r, RAILROAD STRUCTURES. 
 
 extend in length but 7 inches beyond the batter posts ; where- 
 as, many standards call for an extension of from 12 to 18 
 inches. Mortises and tenons are ;} in. X 5 in. X 7 in., with 
 treenails of either white oak or locust. In pile trestling, 
 the piles will be spaced precisely as the posts in the framed 
 structure. 
 
 FRAMED TRESTLE. 
 
 DIMENSIONS OF TIMBERS. 
 
 Floor System : 
 
 Guard-rails, 8 in. x 8 in. X 20 ft., notched 1 in. over ties. 
 Ties, 7 in. X 8 in. x 10 ft., notched 1 in. over stringers. 
 Stringers, 9 in. x 10 in. X 28 ft., notched 1 in. over caps. 
 Bents: Caps, 10 in. X 10 in. x 13 ft. 
 .Plumb posts, 10 in. X 10 in. 
 
 Batter posts, 10 in. x 10 in. 
 
 Sway-braces, 3 in. x 10 in. 
 
 Sill, 10 in. X 10 in. 
 
 DIMENSIONS OF IRON DETAILS. 
 
 Bolts: f in. X 15^ in. ; guard-rails to ties, a bolt in every 
 fourth tie. 
 
 f in. X 21^ in. ; through stringers at separators. 
 
 J in. X 15^ in. ; sway-braces to cap and sill. 
 Drift-bolts : J in. diam. X 23-in. stringers to caps. 
 Treenails : 1 in. X 10 in. 
 
 SIMPLE WOODEN TRUSS BRIDGES. 
 
 1797. The period of construction is a trying one to 
 even the strongest companies, and any expenditure which 
 can either be avoided or put off until this trying period is 
 past should not be incurred. This will explain why so many 
 wooden structures are erected on newly constructed lines, 
 instead of those composed of iron and steel. 
 
 Three forms of trusses will be considered in this chapter, 
 though only the last is employed for bridges for standard 
 gauge railroads. The first and second forms are suited 
 to bridges for narrow-gauge railroads, street-car lines, and 
 highways. 
 
./ RAILROAD vSTRUCTURES. 1247 
 
 jr The parts will be proportioned for the maximum loads to 
 ' which they will be subjected; and, instead of the concen- 
 trated wheel loads, the equivalent live and dead loads per 
 lineal foot of span will be used. 
 
 Before commencing the subject of trusses, a limited space 
 will be given to the subject of the materials entering into 
 these structures, their comparative strength and the meth- 
 ods by which the stresses upon the various parts are deter- 
 mined, and the parts proportioned to resist these stresses. 
 
 1798. Bridge Timber. — The principal varieties of 
 timiber used in bridge building are: 
 
 White Pine. 
 
 Spruce. 
 
 Long-Leaf Yellow Pine. 
 
 Short-Leaf Yellow Pine. 
 
 White Oak. 
 
 Of these, long-leaf yellow pine, on account of its great 
 strength and the fact that it may be had in any desired length, 
 is more used in bridge building than the other four varieties 
 combined. On the Pacific Slope, Washington fir is first in 
 demand, and by most engineers it is considered superior to- 
 the long-leaf pine. 
 
 1799. Forces Operating in Bridges. — The forces 
 to which the timber in a bridge is subjected manifest them- 
 selves in shearing, crushing, bending, and breaking. These 
 forces the student has already become familiar with in his 
 study of the subject of Strength of Materials. 
 
 1800. Transverse Strength of Materials. — The 
 
 transverse strength of a material is that by which it resists 
 breaking. Now, it has been determined by actual experi- 
 ment that in beams of the same material and exactly alike 
 except in breadth, their strengths vary in the same propor- 
 tion as those breadths, i. e., if one is two, three, or ten 
 times broader than the other, its strength will be two, three, 
 or ten times as great. If they are alike except in their 
 
1248 RAILROAD STRUCTURES. 
 
 lengths^ their strength will vary inversely as their lengths, 
 i. e., if one is two, three, or ten times as long as another, it 
 will be only one-half, one-third, or one-tenth as strong. If 
 they are alike except in point of depth, their strengths will 
 vary as the square of those depths, i. e., if one has a depth 
 two, three, or ten times that of another, it will be four, nine 
 or one hundred times as strong. From this it follows that 
 the strength of any beam, of any size, of any material, is in 
 proportion to 
 
 its breadth in inches X square of its depth in inches 
 its length in feet ' 
 
 and if we find by actual trial what center load will break a 
 beam of known size, and then find the ratio between 
 
 its breadth in inches x square of its depth in inches 
 its length in feet 
 
 and its breaking load, this ratio will be that which any 
 similar beam of the same material has to its breaking load. 
 For example, if we take a piece of sound, straight-grained 
 spruce, 4 inches broad and 8 inches deep, and place it hori- 
 zontally upon two supports 8 feet apart, we shall find by 
 gradually loading the beam at its center that the breaking 
 load, including half the weight of the beam itself, is 14,400 
 lb. Substituting these given dimensions in the fraction 
 
 the breadth in inches X square of the depth in inches 
 length in feet ' 
 
 4 X 64 
 we have — = 32, and the ratio between 14,400 and 
 
 o 
 
 14 400 
 32 = — '— — = 450. This ratio is called the constant for 
 
 the center breaking load for beams of spruce, and to find 
 
 the center breaking load for any beam of the same material 
 
 we take its dimensions and substitute them in the following 
 
 formula : 
 
 breadth in sjuarc of depth 
 
 , , . , , inches tn inches „ 
 
 center oreaking load — 7— — —. 7-- X C. 
 
 length tn feet (127.) 
 
RAILROAD STRUCTURES. 1249 
 
 In this formula, 6^ is a constant depending on the kind of 
 timber, and its value for four of the most commonly used 
 varieties is given in Table 52. 
 
 Example. — A spruce beam is 8 in. broad, 12 in. deep, and 20 ft. long; 
 what is its center breaking load ? 
 
 Solution. — Substituting the given dimensions in the above for- 
 mula, we have, using the value for C given in Table 52 for spruce, 
 
 8 X 144 
 center breaking load = — ^ — x 450 = 25,920 lb. Ans. 
 
 One-half the weight in pounds of the beam itself must be 
 deducted from this result to obtain the neat center load. 
 
 1801. Factor of Safety. — In order that a structure 
 may endure, no part of its framework should be strained to 
 the limit of its strength. The ratio between the ultimate 
 or breaking load of a beam and the working load, which is 
 the actual load placed upon it, is called the factor of safety. 
 This factor of safety will vary, according to the character of 
 the structure and the nature of the strains to which it will 
 be subjected. Roof trusses which, except in cases of violent 
 storms, support a quiescent load consisting of the roof cover- 
 ing, snow, ice, etc., together with their own weight, may 
 have a factor of safety as low as 3. But for bridges, espe- 
 cially those carrying locomotives and heavy trains, where 
 the strains are sudden and violent, a factor of safety of at 
 least 6 should be used; and for those on important lines, a 
 factor of 8 is none too great. Hence, in the preceding ex- 
 ample, the beam whose ultimate center load is 25,920 lb., if 
 used in a railroad bridge, should not be subjected to a 
 
 25 920 
 greater center load than — ^ — = 4,320 lb. 
 
 1802. Table of Constants. — By actual experiment, 
 not only with small specimens of timber (usually 1 inch 
 square and 12 inches between supports), but with full-sized 
 beams, the center breaking loads for many varieties of tim- 
 ber and their constants have been determined. The varieties 
 of timber most used in bridge building, together with their 
 
1250 RAILROAD STRUCTURES. 
 
 constants for center breaking loads, are given in the follow- 
 ing table. For highway bridges, use a factor of safety of 
 5; for street car bridges, a factor of 6, and for railroad 
 bridges, a factor of 7 or 8 : 
 
 TABLE 52. 
 
 CONSTANTS FOR CROSS HRBAKING CENTER LOADS. 
 
 Material. 
 
 Pounds. 
 
 Hemlock 
 
 400 
 
 White Pine and Spruce 
 
 450 
 
 Southern Long-Leaf Yellow Pine 
 
 550 
 
 White Oak 
 
 600 
 
 
 
 1803. Inclined Beams. — When the beam, instead of 
 being horizontal, is inclined, the horizontal distance between 
 the points of support must be taken as the span. 
 
 1804. To find tlie side of a square horizontal 
 beam of given span, supported at both ends and 
 required to break under a given quiescent center 
 load : 
 
 YlviW. — Multiply the clear span in feet by the given break- 
 ing load in pounds. Divide the product by the corresponding 
 constant^ Art. 1802. Take the cube root of the quotient. 
 This cube root ivill be the required breadth or depth of the 
 beam, approximately, in inches. 
 
 When the size of the beam is so great that its weight 
 must be taken into consideration, provide for this addi- 
 tional weight by increasing the size of the beam as follows: 
 Calculate the weight of the beam already obtained Then 
 say, as the center load is to half this weight, so is the breadth 
 found to a neiu breadth to be added to it. It will still be 
 
RAILROAD STRUCTURES. 1251 
 
 somewhat too small, owing to the weight of the breadth 
 last added. This additional weight may be easily found 
 and provided for by adding to the breadth. 
 
 Example. — What is the side of a square horizontal white pine beam, 
 12 ft. long between supports, which will break under a quiescent center 
 load of 50,000 lb. ? 
 
 Solution.— 50,000 X 13 = 600,000; 600,000 -r- 450, the constant for 
 white pine, = 1,333. The cube root of 1,333 is 11, almost exactly ; hence, 
 a horizontal beam 11 inches square and 12 feet between supports will 
 break under a quiescent center load of 50,000 lb. Ans. 
 
 In this case, no account is taken of the weight of the 
 beam, which is so small in comparison to its center breaking 
 load that it may be ignored. 
 
 1805. To find the side of a square horizontal 
 beam which will safely bear a given center load : 
 
 Rule. — Multiply the given load by the number of times it 
 is exceeded by the breaking load. Then find by Art. 1804 the 
 side of a square beam to break under this increased load. The 
 beam thus found will be, approximately.^ the safe one for the 
 actual load, exclusive of the weight of the beam itself. If 
 this weight must be included, provide for it by increasing the 
 breadth, as directed in A rt. 1804. 
 
 Example. — What should be the side of a square beam of white pine 
 placed horizontally with 10 feet between supports to safely bear a 
 center load of 12,000 lb., with a factor of safety of 6 ? 
 
 Solution.— 12,000 lb. X 6 = 72,000 lb., the center breaking load for 
 the beam. 72,000x10 = 720,000. 720,000^-450, the constant for 
 center breaking loads for white pine, = 1,600. The cube root of 
 1,600 = 11.7. Hence, the side of the square is 11.7 in. Ans. By 
 increasing the side of the square to 12 inches, we make ample allow- 
 ance for the additional weight of the beam. 
 
 1806. To find the breadth of a horizontal rect- 
 angular beam, supported at both ends, to break 
 under a given quiescent center load, the span and 
 depth of beam being given : 
 
 Rule. — Multiply the center load in pounds by the span in 
 feet. Multiply the square of the depth in inches by the 
 
1252 RAILROAD STRUCTURES. 
 
 constant^ Art. 1802. Divide the first product by the last. 
 The quotient will be, approximately., the breadth. 
 
 If the weight of the beam is so great that it need be 
 taken into consideration, provide for this increased weight 
 by increasing the size of the beam, as directed in Art. 
 1804. 
 
 Example. — A horizontal beam of yellow pine is 18 ft. between sup- 
 ports; the depth of the beam is 12 in. ; what should be the breadth of 
 the beam to break under a quiescent center load of 50,000 lb. ? 
 
 Solution.— 50,000 x 18 = 900.000 lb. The constant for the breaking 
 center load of yellow pine is 550 (Art 1802). The depth, 12, 
 squared = 144;'144 x 550 = 79,200; 900,000 -^ 79,300 = 11.36, the breadth 
 of the required beam. Ans. By increasing the breadth to 12 inches, 
 the increased center load due to the weight of the beam itself is more 
 than provided for. 
 
 1807. To find the depth of a horizontal rect- 
 angular beam, supported at both ends, which 
 shall break under a given quiescent center load, 
 the breadth of the beam and length of span being 
 given : 
 
 Rule. — Multiply the load in pounds by the span in feet. 
 Multiply the breadth in inches by the consta?it given in Art. 
 1802. Divide the first product by the last ; take the square 
 root of the quotient for an approximate depth. Calculate 
 the iveight of a beam having the depth already found ; add 
 half its weight to the given center load, and ivith the new 
 load repeat the calculation ; the result will be close enough 
 for practical purposes, though not exact, ozving to the neg- 
 lect of the iveight of the depth last added. 
 
 Example. — A rectangular horizontal beam of yellow pine is 9 in. 
 broad and 16 ft. between supports; what should be the depth of the 
 beam to break under a quiescent center load of 24,000 lb. ? 
 
 Solution.— 24,000 x 16 = 384,000 lb. The constant for yellow pine 
 (Art. 1 802) is 550. 550 x 9 ^ 4,950. 384,000 -h 4.950 = 77.57. ^^77:57 = 
 8.8 in. A beam of these dimensions, viz.. 9 in. X 8 8 in. X 16 ft., will 
 contain 15,206 cu. in = 8.8 cu. ft. Yellow pine weighs on an average 
 45 lb per cu. ft. Hence, the beam weighs 45 X 8.8 = 396 lb. 396 -h 2 ^ 
 198 lb., which, added to 24.000 lb., the given center load, gives 24,198, 
 
RAILROAD STRUCTURES. 1253 
 
 the total center load of the beam. 24,198x16 = 387,168. 387,168^ 
 4,950 = 78.22, the square root of which is 8.84, the required depth of 
 the beam in inches. Ans. 
 
 From this result the student will see that in providing 
 for the weight of the beam the depth of the beam is 
 increased only .0-i inch, an amount so small that it may be 
 ignored. In actual practice this depth would be increased 
 to 9 inches. 
 
 1 808. Strength of IVooden Pillars. — The strength 
 of wooden pillars, like that of wooden beams, depends 
 much upon their degree of seasoning. Thoroughly seasoned 
 sticks will often support twice as great a load as green 
 ones. This fact should be borne in mind when erecting 
 structures of imperfectly seasoned timber. For permanent 
 structures, timber should not be subjected to more than 
 from ^ to 1^ of its crushing load. 
 
 The following formula by Charles Shaler Smith is for 
 the breaking loads of square or rectangular pillars or posts 
 of moderately seasoned white or yellow pine, with flat ends, 
 firmly fixed and equally loaded: 
 
 Calling either side of the square or the least side of the 
 rectangle the breadth, we have 
 
 Breaking load in pounds per square inch of area of pillar 
 of white or yellow pine = 
 
 5,000 
 
 ^ / square of the length in inches ^ V /j 28.) 
 
 \ square of breadth in inches ) ' 
 
 in which 5,000 equals the breaking load in pounds per 
 square inch for short blocks. 
 
 Example. — A pillar of white pine is 10 inches square and 8 feet long; 
 what is its safe load with a factor of safety of 6 ? 
 
 Solution.— The length equals 8 f t. = 96 in. 96-^ = 9,216. The 
 square of the breadth = 10'^ = 100. Applying the given formula, we 
 have 
 
 Breaking load in pounds per square inch of area = 
 5,000 5,000 
 
 9,216 ^.\ ~ 1.37 
 
 ..C^^x.-x.) 
 
 = 3,650 lb. 
 
1254 RAILROAD STRUCTURES. 
 
 As this is the breaking load, and a factor of 6 is required, the safe 
 load per square inch will be 3,650^6 = 608 lb., nearly, and for 100 
 square inches, the area of the pillar, the safe load will be 608 X 100 = 
 60,800 lb. Ans. 
 
 Example. — A rectangular pillar is 8 in. x 10 in. x 12 ft. ; what is its 
 safe load with a factor of safety of 4 ? 
 
 Solution. — Applying the above formula, we have 
 
 Breaking load in pounds per square inch of area = 
 
 5,000 5,000 
 
 1 /144' --, ~ 2.3 
 
 = 2,174 lb., 
 
 the breaking load per square inch. With a factor of safety of 4, we 
 find the safe load to be 2,174 -h 4 = 543 lb. per sq. in. The area of the 
 pillar is 8 X 10 = 80 sq. in. , and 543 X 80 = 43,440 lb. Ans. 
 
 In applying this formula to composite columns, made up 
 of several sticks bolted together at intervals, give to each 
 stick its proportionate share of the total load to be carried 
 by that member, and then assume that it stands alone and 
 unsupported. This is the only safe rule. Even though 
 the sticks are firmly bolted together with packing-blocks 
 notched into the sides, they should never be assumed to act 
 as one solid stick, as the packing-blocks and washers are 
 sure to grow loose in time. 
 
 1809. Shearing and Crushing. — For shearing and 
 crushing it is generally safe to use a factor of safety of 
 2 or 3. Use for working values of the shearing stress along 
 the grain ^ for 
 
 White pine and spruce 200 lb. per sq. in. 
 
 Long-leaf yellow pine 400 lb. per sq. in. 
 
 Short-leaf yellow pine. 300 lb. per sq. in. 
 
 White oak 600 lb. per sq. in. 
 
 For crushing across the grain, take for working values of 
 seasoned timber, for 
 
 White pine and spruce 300 lb. per sq. in. 
 
 Long-leaf yellow pine 500 lb. per sq. in. 
 
 Short-leaf yellow pine 450 lb. per sq. in. 
 
 White oak 1,000 lb. per sq. in. 
 
RAILROAD STRUCTURES. 1255 
 
 For crushing endivisc (short blocks), take for working 
 values for 
 
 White pine 2,500 lb. per sq. in. 
 
 Long-leaf yellow pine 3,000 lb. per sq. in. 
 
 Short-leaf yellow pine 2,800 lb. per sq. in. 
 
 White oak 2,750 lb. per sq. in. 
 
 1810. Tension. — Wood fiber is much stronger in ten- 
 sion than in any other way, and, as a result, it may be said 
 that wood seldom or never breaks in pure tension in actual 
 service. In long sticks in tension, the grain runs more or 
 less across the line of the stick, and a liberal allowance must 
 be made for the reduction of the stick by framing it. In 
 actual work, it is not well to rely upon a working stress in 
 tension of more than 2,000 or 3,000 pounds per square inch 
 for ordinary bridge timber. 
 
 EXAMPLES FOR PRACTICE. 
 
 1. A stick of white pine is subjected to a shearing stress along the 
 grain of 40,000 lb. ; how many square inches of surface are necessary to 
 sustain this stress with a factor of safety of 3 ? 
 
 Solution. — From Art. 1809, we find the safe working value for 
 shearing stress per square inch along the grain for pine is 200 lb., and 
 to sustain a stress of 40,000 lb., it will require as many square inches of 
 surface as 200 is contained in 40,000, which is 200 sq. in. Ans. 
 
 2. An oak tie-beam is subjected to a shearing stress across the grain 
 of 62,000 lb.; how many square inches of surface are necessary to 
 sustain this stress? Ans. 103.3 sq. in. 
 
 1811. To find tlie safe dimensions for a rectan- 
 gular horizontal beam of jriven span, supported at 
 both ends, and which is at the same time subjected 
 both to a transverse strain and to a longitudinal 
 tensile or pulling one, or to a longitudinal com- 
 pressive one : 
 
 Rule. — When the longitudinal strain is tensile, ^nd sepa- 
 rately the safe dimensions as if for a beam alone, and as if 
 for a tie alone, and add the ttvo resulting areas together. 
 When the lo?igitudinal strain is eompressive, find separately 
 
1250 
 
 RAILROAD STRUCTURES. 
 
 »= 
 
 Plunk. 
 
 TJs: 
 
 h 
 
 3x8 
 
 3x8 Separaton. 
 k 
 
 
 J 5* 
 
 UI 
 
 ill! 
 
 r' 
 
 1: 
 
 B 
 
 
 ^m-k 
 
 Fig. 629. 
 
RAILROAD STRUCTURES. 1257 
 
 the safe dimensions as if for a beam alone, and as if for a 
 pillar alone, and add the two resulting areas together. 
 
 Example. — A rectangular horizontal beam of yellow pine of 14 feet 
 span is to sustain a uniformly distributed transverse load of 40,000 lb., 
 and a pulling stress of 30,000 lb. , with a factor of 6 ; what should, be the 
 dimensions of the beam ? 
 
 Solution. — A uniformly distributed load of 40,000 lb. is equivalent 
 to a center load of 20,000 lb. A safe center load of 20,000 lb. with a 
 factor of 6 is equivalent to a center breaking load of 120,000 lb. Apply- 
 ing the rule given in Art. 1804, we have 120,000x14 = 1,680,000. 
 The constant for center breaking loads for yellow pine (Art. 1802) is 
 550. 1,680,000-^550 = 3,054, the cube root of which is 14. 5. This gives 
 in inches the side of a square beam which will safely carry the given 
 load. 
 
 From Art. 1810 we conclude the safe working stress in tension per 
 square inch for yellow pine to be, say 3,000 lb. per square inch. The 
 given tensile stress is 30,000 lb., to resist which it will require as many 
 square inches as 3,000 is contained in 30,000, which is 10. We, there- 
 fore, add 10 sq. in. to area of the given beam by increasing either the 
 breadth or depth -^^ of an inch. Ans. 
 
 1812. Bridge Loads. — The trusses will be propor- 
 tioned for the following loads, viz : 
 
 Highway bridges, combined live and dead load equivalent 
 to 1,500 pounds per lineal foot. 
 
 Street car bridges, combined live and dead load equivalent 
 to 4,000 pounds per lineal foot. 
 
 Railroad bridges, combined live and dead load equivalent 
 to 6,000 pounds per lineal foot. 
 
 The foregoing are the maximum loads to which they will 
 be subjected. 
 
 The forms of trusses given will not be used for spans ex- 
 ceeding 30 feet for railroads, or 40 feet for highways. Where 
 larger spans occur, other and more complicated forms of 
 trusses will be employed, the designing of which properly 
 belongs to the bridge department. 
 
 1813. King-Rod Truss. — The simplest form of a 
 bridge truss is shown in Fig. 029. This is called a king-rod 
 truss, from the rod a b, which extends from the head a of the 
 ratters to the base /) of the needle-beam c. Heavy cast 
 
1258 RAILROAD STRUCTURES. 
 
 washers are placed under both head and nut of the king-rod, 
 and when the nut is tightened, ail parts of the truss are put 
 under strain. 
 
 Let </, d be points half way between the king-rod and the 
 abutments %i\ w\ then, the king-rod a b will sustain all the 
 weight resting upon the beam e f, between the points d^ d\ 
 also, half the weight of the needle-beam c, and of the load 
 resting upon it. From an inspection of the plan, it will be 
 readily seen that all that portion of the bridge between the 
 points d^ d and the abutments w, w is supported by the abut- 
 ments. The entire weight of the truss and its load is sus- 
 tained ultimately by the abutment walls, but the portion d, d 
 reaches them by first traveling up the king-rod a b \.o the 
 head of the rafters and then down them to their feet, where 
 it is transmitted directly to the abutments. 
 
 From an inspection of the plan, it will be readily seen 
 that all of the floor-beams g, h, i, k, I, m, and n rest upon 
 the needle-beam, and, instead of one span of 20 feet, they 
 form two spans of 10 feet each, which permits us to use 
 much smaller floor-beams than would be required for a span 
 of 20 feet. Assuming that the total dead load (i. e., the load 
 of the structure itself) and the live load (i. e., the load 
 placed upon the bridge, but distinct from the weight of the 
 structure itself) are equivalent to 100 lb. per sq. ft. of bridge 
 floor, we have the total load carried by two king -rods equal 
 to 10 X 17 X 100 = 17,000 lb., and for one king-rod the load 
 
 z 
 Let the height of the peak a of the truss be G feet above 
 the tie-beam e f. Draw the rafters conforming to the 
 dimensions given in the plan. Draw the line a b, repre- 
 senting the king-rod, and lay off upon it downwards from a' 
 to a scale of 10,000 lb. to the inch, the distance a' o = 8,500 lb. 
 Complete the parallelogram a' q o p and draw the diagonal 
 q p. Then a p and a q will measure the stresses upon 
 the rafters due to the weight upon the king-rod, and r p 
 and r q the pulling forces produced by the same weight; 
 but they act along the tie-beams in opposite directions. 
 
RAILROAD STRUCTURES. 1259 
 
 causing a stress equal to one of them throughout the tie- 
 beam. 
 
 To resist the stress «/> or a q, running lengthwise through 
 the rafter from head to foot, the rafter must be regarded as 
 a pillar^ and the safe area required to resist this stress we 
 find by applying formula 128, given in Art. 1808, viz.: 
 
 Breaking load in pounds per square inch of area of yellow 
 
 pine — 
 
 5,000 
 
 ^ , / square of length in inches ^^A 
 
 1 + (— ^ ;, \i,i ■ ■ 1 X .004) 
 
 \ square of breadth m inches J 
 
 The length of rafter as measured along its center line 
 from joint to joint is 11 ft. 6 in. = 138 in. 
 
 Assuming a breadth of 6 in. for the rafters, we have 
 Breaking load in pounds per square inch of area = 
 5,000 
 
 i-,(f!x.oo.; 
 
 = 1,604 lb., 
 
 which, with a factor of safety of 8, gives a safe load of 
 
 1,604 _-_ „ 
 
 -!— — = 200 lb. per sq. m. 
 
 The stress a' p measured by the given scale equals 
 9,000 lb. ; hence, the area required to resist this stress will 
 
 be ' = 45 sq. in. The breadth of the rafter has been 
 
 45 
 assumed as 6 inches; hence, the depth must be -v^ = 
 
 1\ inches. Since the usual market sizes of timber run only 
 in even inches, we will make the depth of the rafter 8 inches. 
 In this bridge the plank flooring does not rest directly 
 upon the tie-beams, but upon the floor-beams g and «, 
 which are spiked to the tie-beams. The tie-beams are 
 gained 2 in. to form footings for the rafters, and the tie-rods 
 pass through them, reducing their actual span to 10 ft., one- 
 half the total span of the bridge. If the tie-beams were 
 given smaller dimensions than the rafters, they would appear 
 weak, and, though unnecessarily large, we give them the 
 same dimensions, viz., 6 in. X 8 in. 
 
1260 RAILROAD STRUCTURES. 
 
 We determine the dimensions of the needle-beam c by first 
 finding the load which it must sustain. The king-rods 
 support the needle-beam, which in turn supports the tie- 
 beams, floor-beams, and floor, and, hence, both sustain prac- 
 tically the same load. The total uniform load we have 
 already determined to be 17,000 lb., which is equivalent to 
 a center load of 8,500 lb. This gives, with a factor of 
 safety of G, a center breaking load of 8,500 X 6 = 51,000 lb. 
 The span from center to center of king-rods is 16.5 ft. 
 Assuming for the needle-beam a depth of 12 in., we have, 
 from Art. 1 806, 
 
 . ,, ,. 51,000X16.5 ,.^. 
 
 required breadth = , -— — = 10.6 m. 
 
 1/i X 5oO 
 
 As it is safe to say that the bridge will never be loaded 
 to these limits, owing to the difficulty of loaded teams passing 
 on the bridge, we make the breadth of the needle-beam an 
 even 10 in. 
 
 The floor-beams have a clear span of 9 ft. 7 in., or 9.58 ft. 
 
 The distance from center to center of floor-beams is 2 ft. 
 
 8 in., or 2.66 ft. Hence, the total distributed load on each 
 
 beam, at 100 lb. per sq. ft., is 2.66 X 9.58 X 100 = 2,548 lb., 
 
 2 54S 
 equal to a center load of ' ' = 1,274 lb. Allowing a 
 
 Xi 
 
 factor of safety of 8, we have a center breaking load of 
 
 1,274 X 8 = 10,192 lb. 
 
 Assuming for floor-beams a depth of 8 in., we find from 
 
 Art. 1806, 
 
 ... ,^, 10,192x9.58 _ ^^ . 
 
 required breadth = — -—^ — — — = 2.77 in. 
 
 ^ 8' X 550 
 
 This breadth we increase to 3 in., the standard dimension 
 nearest to the one required, making the cross-section dimen- 
 sion of the floor-beams 3 in. X 8 in. Their length should be 
 equal to the total length of the bridge, or 23 ft. The floor- 
 beams and stringers do not come in direct contact with the 
 stone abutments, but rest upon timbers j, s, called wall 
 plates, by means of which the weight of the bridge is dis- 
 tributed over the entire bridge seat. The wall plates are of 
 
RAILROAD STRUCTURES. 
 
 1201 
 
 oak timber, 4 in. by G in., and extend the full length of the 
 abutments. 
 
 The dimensions of the king-rod may be found in Table 53. 
 
 TABLE 53. 
 
 WEIGHTS AND STRENGTHS OF IRON BOLTS. 
 
 Ends Enlarged or Upset. 
 
 Ends Enlarged or Upset. 
 
 Diam- 
 eter of 
 
 Weight per 
 
 Breaking 
 
 Diam- 
 eter of 
 
 Weight per 
 
 Breaking 
 
 Shank. 
 
 Foot Run. 
 
 Stress. 
 
 Shank. 
 
 Foot Run. 
 
 Stress. 
 
 Inches. 
 
 Pounds. 
 
 Pounds. 
 
 Inches. 
 
 Pounds. 
 
 Pounds. 
 
 i 
 
 .661 
 
 8,803 
 
 If 
 
 8.10 
 
 102,368 
 
 tV 
 
 .837 
 
 11,133 
 
 ; Iff 
 
 8.69 
 
 109,760 
 
 f 
 
 1.03 
 
 13,754 
 
 U 
 
 9.30 
 
 117,600 
 
 u 
 
 1.25 
 
 16,621 
 
 m 
 
 9.93 
 
 125,440 
 
 f 
 
 1.49 
 
 19,779 
 
 2 
 
 10.6 
 
 133,728 
 
 1 3 
 
 1.75 
 
 23,296 
 
 H 
 
 12.0 
 
 142,912 
 
 i 
 
 2.03 
 
 26,880 
 
 H 
 
 13.4 
 
 160,384 
 
 H 
 
 2.33 
 
 30,912 
 
 H 
 
 14.9 
 
 178,528 
 
 1 
 
 2.65 
 
 35,168 
 
 n 
 
 16.5 
 
 198,016 
 
 ItV 
 
 2.99 
 
 37,632 
 
 H 
 
 18.2 
 
 218,176 
 
 H 
 
 3.35 
 
 42,336 
 
 2| 
 
 20.0 
 
 239,456 
 
 lA 
 
 3.73 
 
 47,264 
 
 H 
 
 21.9 
 
 261,632 
 
 H 
 
 4.13 
 
 52,192 
 
 3 
 
 23.8 
 
 284,928 
 
 lA 
 
 4.56 
 
 57,568 
 
 H 
 
 27.9 
 
 315,840 
 
 If 
 
 5.00 
 
 63,168 
 
 H 
 
 32.4 
 
 366,464 
 
 ItV 
 
 5.47 
 
 68,992 
 
 3f 
 
 37.2 
 
 420,448 
 
 H 
 
 5.95 
 
 75,264 
 
 4 
 
 42.3 
 
 478,464 
 
 ItV 
 
 6.46 
 
 81,536 
 
 H 
 
 47.8 
 
 508,480 
 
 ll 
 
 6.99 
 
 88,256 
 
 H 
 
 53.6 
 
 570,080 
 
 iH 
 
 7.53 
 
 95,200 
 
 4| 
 
 59.7 
 
 635,040 
 
 The load which each king-rod sustains we found to be 
 8,500 lb. A rod which would safely sustain this load 
 
1262 
 
 RAILROAD STRUCTURES. 
 
 with a factor of safety of would break under a load of 
 8,500 X G = 51,000 lb. 
 
 Referring to the table, we find in the column headed 
 Breaking Stress, the number most nearly corresponding to 
 51,000, which is 52,192 lb. This stress calls for a rod 
 
 1 
 
RAILROAD STRUCTURES. 1263" 
 
 1:^ in. in diameter, which is the diameter we specify for 
 
 king-rods. 
 
 The stress in the rafters produces a shearing stress along 
 
 the grain of the tie-beam at the footing of the rafter. This 
 
 stress is equal to r /, or 7,800 lb. We find in Art. 1809 
 
 that the working stress for shearing along the grain in 
 
 yellow pine is 400 lb. per sq. in., and to resist a shearing 
 
 7 800 
 stress of 7,800 lb. it will require ' ^ = 19.5 sq. in. There 
 
 400 
 
 must accordingly be sufficient space between the foot of the 
 
 rafter and the end of the stringer to give a superficial area 
 
 of at least 19.5 in. As we have made this distance 12 in., 
 
 giving a superficial area of 6x12 = 72 in., there is no 
 
 question of the security of this joint. The bolts /, / passing 
 
 through the tie-beam at the foot of the rafter serve only to 
 
 keep the rafter in place. The needle-beam projects 4 ft. 3 in. 
 
 outside the truss, as shown in detail 2X A. A brace u runs 
 
 from this projecting needle-beam to the head of the rafters. 
 
 It is fastened with spikes, and serves to stiffen the truss and 
 
 prevent lateral vibration. 
 
 The joint of the rafters at their head, together with king- 
 rod and washers, is shown in detail at B. 
 
 In Fig. 630 is illustrated another form of the king-rod 
 truss, in which the stiffeners a b, c d are introduced, their 
 object being to stiffen the rafters and prevent their bending 
 under the longitudinal stress transmitted to them by the 
 king-rod. The stiffeners extend from the middle of the 
 rafters to the base of the king-rod, where they abut against 
 a cast-iron angle block. A cast-iron socket is let into the 
 rafter at the head of each stiffener, and holds it securely in 
 place. The angle block at the foot of the king-rod has two 
 ribs which project 1 in. below the base of the block. 
 Grooves are cut in the tie-beam to receive these ribs, which 
 hold the angle block firmly in place. A hole is cast in the 
 angle block through which the king-rod passes. The 
 stiffeners practically reduce the length of the rafters to 
 one-half their actual length, so far as their sustaining power 
 as pillars is concerned. 
 
1264 RAILROAD STRUCTURES. 
 
 The bridge shown in the figure is to accommodate the 
 traffic of both street cars and highway. The parts are pro- 
 portioned for an equivalent live and dead load of 4,000 lb. 
 per lineal foot of bridge. The material is long-leaf yellow 
 pine. The stresses are calculated as were those for the 
 bridge shown in Fig. G29. The clear span of the bridge is 
 28 ft. , and the breadth from outside to outside of truss is 
 19 ft. 4 in., and the height of truss above the tie-beams 
 is 9 ft. The two king-rods ^'/support that portion of the 
 bridge and its load between the points j, y, or together, one- 
 half the total load. 
 
 At 4,000 lb. per lineal foot, the load between j, _>/ is 
 4,000 X 14= 56,000 lb., one-half of which, or 28,000 lb., is 
 carried by each king-rod. Accordingly, we lay out the out- 
 lines of the rafters, and though we do not yet know their 
 depth, we can draw their upper edges, which will not alter 
 their position, and form two sides of our parallelogram of 
 forces. We next draw the line e f^ which will be the center 
 line of the king-rod. Upon this lay off from g, to a scale of 
 20,000 lb. to the inch, the distance ^//^ 28,000 lb. Com- 
 plete the parallelogram g I h k. Then the equal sides g I 
 and g k will represent by the same scale the longitudinal 
 stress in the rafters. These stresses, which we find to be 
 27,300 lb., pass down the rafters and are taken up by the 
 abutments. To resist these stresses, the rafters act as 
 pillars. As before stated, the stiffeners a b and c d virtually 
 reduce the length of these pillars, i. e., the rafters, to one- 
 half their total length. Now, assuming that a rafter with 
 a breadth of 8 in. will meet the requirements, we must find 
 the requisite area of the rafter by the method given in Art. 
 1 808. . The total length of the rafter measured along its cen- 
 ter line is 16 ft. 6 in. ; hence, the length of one pillar is one- 
 half of the total length of the rafter, or 8 ft. 3 in. , equal to 99 in. 
 
 Applying formula 128, given in Art. 1808, we have 
 Breaking load per square inch of area of pillar = 
 5,000 5,000 .. .^. ,. 
 
 1 + (^ X .OOl) 
 
RAILROAD STRUCTURES. 12G5 
 
 With a factor of safety of 8, this rafter will bear per 
 
 square inch of area, -^— — = 388 lb. 
 
 8 
 
 The stress g I upon this rafter is 27,300 lb., and to safely 
 resist the stress it will require a rafter whose cross-sectional 
 
 area is J — = 70 sq. in. As we have assumed a breadth 
 o88 
 
 70 
 of 8 in., the depth will be — = 8.75 in. 
 
 8 
 
 The rafter must be notched on the under side to receive 
 the cast-iron socket for the stiffener ; consequently, it will be 
 best to make the depth 10 inches, a size that is readily 
 obtained in the market. 
 
 In the parallelogram g I h k, the diagonal k I represents 
 
 the pull along the tie beam. Half of this stress ;// / is in 
 
 one direction from the foot of the king-rod, and half in k 
 
 in the other direction, making a uniform stress of in I = 
 
 23,500 lb. throughout the tie-beam. The effect of this pull 
 
 is to shear off the end of the tie-beam against which the 
 
 rafter abuts. By reference to Art. 1 809, we find the safe 
 
 shearing stress along the grain for yellow pine is 400 lb. per 
 
 sq. in., and to resist a stress of 23,500 lb. it will require 
 
 .23 500 
 ' * ^ = 59 sq. in., nearly. The distance from the foot of 
 400 
 
 the rafter to the end of the tie-beam is 12 in. Assuming a 
 
 breadth of 8 in. for the stringer, we will have to oppose the 
 
 given stress of 23,500 lb., an area of 12 X 8 = 90 in., or 
 
 nearly double the required area. 
 
 The stiffeners a b and c </ support only half the weight of 
 the rafter, and serve only to keep the rafter from bending 
 under its longitudinal stress. If proportioned for their 
 actual loads, they would appear weak and out of proportion. 
 We accordingly make them 4 in. X 8 in. 
 
 The size of the king-rod we determine as follows: The 
 load which it must sustain we have determined to be 
 28,000 lb. With a factor of safety of G, its ultimate, or 
 breaking, load will be 28,000 X G = 1G8,000 lb. By refer- 
 ence to Table 53, Art. 1813, we find the diameter of a 
 
1266 RAILROAD STRUCTURES. 
 
 bolt with a breaking stress of 108,000 lb. is nearly 2:^ in. 
 We accordingly specify a 2i-in. king-rod. 
 
 The king-rod passes through both tie-beam and needle- 
 beam, being fitted at both head and nut with large cast 
 washers. 
 
 As all floor-beams rest upon the needle-beam, it must 
 therefore carry half the weight of the floor and its load, i. e., 
 it must carry all the load between the points j, y. This we 
 have already found to be 4,000 X 14 = 50,000 lb., a uni- 
 formly distributed load which is equivalent to a center load 
 
 of 5^i^ = 28,000 lb. The length of the needle-beam from 
 
 center to center of king-rods is 18 ft. 8 in. A beam of this 
 length and capable of bearing a center load of 28,000 lb. 
 would be unwieldy. We accordingly truss the needle-beam 
 by putting in a vertical strut q of cast iron at the center 
 of the beam, and throw the stress upon the ends of the 
 tie-beam by means of the rods r, r, thus converting a 
 transverse center load into a /////. By this means we re- 
 duce the theoretical span of the needle-beam to one-half 
 of its actual length. This truss is the reverse of the 
 one just described, the strut q in the truss P s p (see 
 section C) taking the place of the king-rod e f \x\. the 
 truss n e o. 
 
 The strut q supports one-half the load carried by the 
 needle-beam, that is, all that part of its load between the 
 two points X, X, and practically divides the needle-beam into 
 two spans, each equal to one-half its lengrti from center to 
 center of the king-rods, or 9 ft. 4 in. long. Each of these 
 beams will support one-half of the total load of the needle- 
 beam, or 28,000 lb., which is a uniformly distributed load, 
 
 and equivalent to a center load of , — ^— — = 14,000 lb. 
 
 With a factor of safety of 0, the center cross breaking load 
 will be 14,000 X 6 = 84,000 lb. Assuming a breadth of 
 12 in. for the needle-beam, we determine its depth by 
 Art. 1807. The constant for center breaking loads for 
 long-leaf yellow pine is 550 (Art. 1802). 
 
RAILROAD STRUCTURES. 1267 
 
 Substituting the known values in formula 127, 
 
 breadth square of depth 
 
 , , . J J in inches in incites ^ 
 
 center breaki7ig load = — -. , — -, r—^ X C. 
 
 length of span tn feet 
 
 and denoting the required depth by x, we have 
 84,000 = ^-1^X550; 
 
 , - 783,720 -, ,o w 
 
 whence, ^. = ___ = „8. 75, 
 
 and X— 10.9 in., nearly, 
 
 the required depth in inches of the needle-beam. 
 
 Making the length of the strut 2 ft. 6 in., we draw lines 
 p s, p s to denote the straining rods r, r of the truss. Lay- 
 ing off from s upwards, to a scale of 20,000 lb. to the inch, 
 the distance s t = 14,000 lb., the center load, we complete 
 the parallelogram s u t v. The sides s «, s v represent the 
 stress in the straining rods r, r. By the given scale these 
 sides measure 23,000 lb. This stress we divide between the 
 two rods w, shown in section in the detail at A. The stress 
 
 upon each rod is, therefore, -^- — = 11,500 lb. With a 
 
 factor of safety of 6, the breaking stress would be 11,500 X 
 
 6 = 09,000 lb. We accordingly look in Table 53 for the 
 
 diameter of a rod with a breaking stress of 69,000 lb., and 
 
 find it to be lyV in. To insure ample safety, we increase 
 
 the diameter to 1^ in. The pull placed upon the rods r, r 
 
 places the needle-beam// under compression to an amount 
 
 equal to u y, which, by the given scale, amounts to 21,500 lb. 
 
 We find by reference to Art. 1809, that for endwise 
 
 crushing stress we may use a working stress of 3,000 lb. per 
 
 sq. in. Hencej to resist this stress of 21,500 lb., we must 
 
 21 500 
 add to the area of the needle-beam ., ' .^ =7.17 sq. in., 
 
 nearly. To hold the strut q in place, ribs cast with the strut 
 fit into notches cut into the under side of the needle-beam. 
 These notches, as well as those cut in the side of the needle- 
 beam for the straining rods, somewhat reduce the area of 
 
1268 
 
 RAILROAD STRUCTURES. 
 
RAILROAD STRUCTURES. 12G9 
 
 its cross-section, and to insure ample strength we increase 
 the depth of the needle-beam to 12 in. 
 
 The straining rods are fitted at both ends with nuts and 
 heavy cast washers which cover the entire end of the needle- 
 beam, as shown in the cross-section C, and in detail at B. 
 Ribs are cast on the backs -of the washers, which fit into 
 grooves cut into the ends of the needle-beam. 
 
 The floor system is so arranged that the street cars shall 
 use only one side of the bridge, leaving the other side ex- 
 clusively for vehicles. The rails are laid directly over 
 stringers, which are proportioned to carry cars loaded to 
 their utmost capacity. 
 
 A fully loaded street car weighs 10 tons. This is carried 
 on a wheel base (the horizontal distance between the cen- 
 ters of wheels) of 6 ft. 6 in. Say this is equivalent to a 
 center load of 7 tons, or 3^ tons on each stringer. The 
 depth of these stringers will, of course, be the same as that 
 of the floor-beams, viz., 12 in. Their breadth we find by 
 Art. 1806. A safe center load of 3^ tons, with a factor 
 of safety of 7, would be equivalent to a breaking center 
 
 1 A (^Ax. .nAAAiK 49,000X14 686,000 ^^. 
 
 loadof2Htons, or 49,0001b. -^^r^^^- = -j^^^ = 8.6m., 
 
 the required breadth of track stringers. The factor of 
 safety being large, and as a part of the load is distributed 
 among adjacent floor-beams, we may safely specify for these 
 stringers a breadth of 8 in. 
 
 1814. Queen-Rod Truss. — The form of truss shown 
 in Fig. 631 is called a queen-rod truss, or, more briefly, 
 a queen truss. The essential features of this truss, and 
 those which distinguish it from the king-rod truss already 
 described, are the two queen-rods k^ I and the strain- 
 ing beam gh. The remaining parts, viz., the tie-beam a b, 
 the rafters c d and c f, and the needle beams ;« and «, are 
 similar to those found in the king-rod truss, or king truss. 
 
 This form of truss is frequently used for short spans, on 
 new railroad work, especially if timber is abundant and 
 economy in cost a first consideration. 
 
1270 RAILROAD STRUCTURES. 
 
 The height of the truss should be such that the slope of 
 the rafters will be approximately 45°, which is the angle at 
 which a brace exerts its greatest strength. The queen-rods 
 should divide the clear span (the space between the abut- 
 ments) into three equal parts. 
 
 In Fig. 631 the span is 36 ft. in length, the height of the 
 truss above the tie-beam is 11 ft., and the queen-rods divide 
 the span into three equal parts of 12 ft. each. The points 
 y and z are midway between the abutments and the queen- 
 rods, and the point x is midway between the queen-rods. 
 The queen-rod k supports its own weight and that part of 
 the truss included between the points x and j^, together with 
 its load ; the queen-rod / supports its own weight, together 
 with that part of the truss included between the points 
 X and z and its load. The parts of the truss between the 
 abutments and the points y and z are supported by the 
 abutments. 
 
 The truss shown in Fig. 631 is designed for a railway of 
 standard gauge, and for an equivalent dead and live load of 
 6,000 lb. per lineal foot of span. The load for each truss 
 
 per lineal foot will, therefore, be -^-- — = 3,000 lb. The 
 
 2 
 
 distance x z is 12 ft. The load upon the queen-rod / will, 
 
 therefore, be 3,000 X 12 = 36,000 lb., and with a factor of 
 
 safety of 6, the ultimate or breaking stress will be 
 
 36,000 X 6 = 216,000 lb., which, from Table 53, we find is 
 
 the breaking stress for a rod of 2f in. diameter. 
 
 We accordingly lay off from o, on the center line of the 
 
 queen-^od, to a scale of 20,000 lb. to the inch, the distance 
 
 <?/, equal to 36,000 lb. We then complete the parallelogram 
 
 r p q^ and find that the stress of 36,000 lb., which the 
 
 queen-rod / sustains, passes to the head o of the rod, where 
 
 it is converted into two longitudinal stresses, one of which 
 
 o q travels down the rafter c d, and is taken up by the 
 
 abutment /:, while the other o r moves in the direction 
 
 o r. An equal stress is placed upon the straining beam by 
 
 the load carried by the queen-rod k. This stress moves in 
 
 the direction g h. These two stresses reacting upon each 
 
RAILROAD STRUCTURES. 1271 
 
 other produce a stress throughout the straining beam equal 
 to one of them. This stress o r, we find by the given scale 
 of forces, amounts to 42,800 lb. The stress oq^ by the same 
 scale, amounts to 56,000 lb. The rafter c </, in resisting this 
 stress, acts as a pillar. In determining the dimensions of 
 this rafter, we will assume a certain breadth, say 12 in., and 
 then find the depth necessary to sustain the given load, the 
 variety of timber used being yellow pine. The length of 
 the rafter is 16 ft. 4 in.= 196 in. 
 
 From formula 128, Art. 1808, we have 
 
 Breaking load per square inch of area of pillar = 
 
 5,000 
 
 / square of length in inches \ 
 \square of breadth in inches ) 
 
 Substituting given values, we have 
 Breaking load per square inch of area of pillar = 
 5,000 5,000 
 
 i + (^x.oo.)--^ 
 
 = 2,415 lb. 
 
 With a factor of safety of 6, the working stress will be 
 
 2 415 
 
 ' ' . = 402 lb. per sq. in., and to resist the given stress 
 
 of 56,000 lb., it will require a cross-sectional area of — ^,— - = 
 
 402 
 
 139 sq. in. As the assumed breadth of the rafter is 12 in., 
 
 139 
 the depth will be --— = 11.58 in., or, using the next larger 
 1* 
 
 size in even inches, we have 12 in. x 12 in. for the size of 
 the rafter. 
 
 The stress upon the straining beam ^ h is 42,800 lb., and 
 its length, as measured on the center line of the beam, is 12 ft. 
 6 in. It will be at once apparent that with less stress and 
 with less length than the rafter e d, the straining beam may 
 be of smaller size and yet have the same factor of safety. 
 It i > customary, however, to make both rafter and straining 
 beam of one size, as they form a better joint at the queen- 
 rods and give an impression of greater strength. The 
 
1272 RAILROAD STRUCTURES. 
 
 needle-beams' in and » serve only as ties to hold the trusses 
 in position. The cross-ties are laid directly upon the tie- 
 beams, 16 in. from center to center. At 0,000 lb. per lineai 
 foot, the uniformly distributed load upon each cross-tie is 
 G,000 X 1.333 = 7,998, say 8,000 lb., which is equivalent to a 
 center load of 4,000 lb. With a factor of safety of G, the center 
 breaking load will be 4,000 X 6 = 24,000 lb. The distance 
 between tie-beams is 12 ft. 10 in., say 13 ft. Assuming a 
 breadth of 8 in. for the cross-ties, and denoting the required 
 depth by -r, we find the depth by applying the rule given in 
 Art. 1807, as follows: 
 
 24,000 = ^^5^ X 550, 
 Jo 
 
 whence, ;r'' = 70.90, 
 
 and .r = 8.4 in. 
 
 As we notch down the ties 1 in. on the tie-beams, we 
 increase this depth to 9 in. 
 
 The queen-rods virtually divide the bridge span into three 
 short spans of 12 feet each. We accordingly find the 
 dimensions of the tie-beams for spans of that length. The 
 load upon each tie-beam we assume at 3,000 pounds per 
 lineal foot. The total uniformly distributed load on the tie- 
 beam is, therefore, 3,000 X 12= 36,000 lb., which is equiva- 
 
 or* AAA 
 
 lent to a center load of — '- — = 18,000 lb. With a factor of 
 
 z 
 
 safety of 6, we have a breaking center load of 18,000 X 6 = 
 
 108,000 lb. 
 
 Assuming a breadth of 12 inches for the tie-beam, we find 
 
 the depth by the rule given in Art. 1 807. Denoting the 
 
 required depth in inches by ,r, we have 
 
 108,000 =:^^^^^^ — X 550; 
 
 550-r' = 108,000, 
 whence, ;f' = 196.36 
 and X = 14 in., the required depth of the tie-beam. 
 
 Besides the transverse stress upon the tie-beam, there is a 
 
RAILROAD STRUCTURES. 1273 
 
 longitudinal pull / q^ which amounts to 42,800 pounds. 
 Allowing a working stress in tension of 3,000 pounds per 
 
 square inch, it will require ' = 14.2G square inches of 
 
 3,000 
 
 area to resist this pull. We add this area to that already 
 
 obtained for the tie-beam, being careful to make the increase 
 
 in one dimension only, viz., the breadth. This gives us for 
 
 the final dimensions of the tie-beam a breadth of say 
 
 13 inches and a depth of 14 inches. 
 
 The longitudinal stress in the rafter c d develops a shear- 
 ing stress along the grain at the foot of the rafter equal to 
 the pull in the tie-beam, or 42,800 pounds. 
 
 Allowing a working stress for shear along the grain of 
 
 42 800 
 400 lb. per sq. in., it will require— j—— ■= 107 sq. in. to resist 
 
 this stress. The distance from the foot of the rafter to the 
 end of the tie-beam is 12 in. ; hence, the superficial area 
 opposed to this shearing stress is 13 X 12=156 sq. in., 
 which insures ample safety. The feet of the rafters are 
 bolted to the tie-beams, thus preventing any lateral move- 
 ment. 
 
 The needle-beams /;/ and n serve two purposes, viz., as 
 ties to hold the tie-beams in position, and as supports for 
 the braces j, s which maintain the trusses in an upright 
 position. These braces are fastened in place with boat 
 spikes. The trusses are further braced by three sets of X 
 braces /, ^, as shown in the cross-section B. Each set has a 
 length equal to one-third of the span. The ends of the 
 braces are spiked to the tie-beams and bolted together at 
 the point where they cross each other. On the inside of 
 each tie-beam, directly over the bridge seat, a groove is cut 
 1 in. in depth and 4 in. in breadth, to receive the spreader 
 «, as shown in the detail. These spreaders are 4 in. x 12 in., 
 and are held in place by the tie bolts v, v, which are 1 in. in 
 diameter and fitted with cast washers. The effect of 
 the rails is to distribute the loads concentrated upon the 
 driving wheels of the locomotive over the entire wheel base, 
 so that cross-ties which individually could not sustain these 
 
1274 RAILROAD STRUCTURES. 
 
 concentrated loads are yet amply strong enough for their 
 share of the distributed load. The trusses do not rest 
 directly upon the bridge seats, but upon two G in. X 9 in. 
 oak timbers iv, w, which extend the full length of the 
 bridge seat and distribute the weight of the bridge over the 
 entire foundation. 
 
 The cast-iron shoulder block at head of rafters is shown 
 in detail at D. The bridge seats are 2 ft. in breadth, and 
 the abutments 3 ft. in thickness at the bridge seat. The 
 faces of the abutments are vertical, while their backs have 
 a batter of 1^ inches to the foot. 
 
 WATER STATIONS. 
 
 1815. Water stations are points along a railroad 
 where the engines stop to take in water. Their distance 
 apart will depend mainly upon the amount of the traffic, 
 but somewhat upon the grades. On roads with a light 
 traffic, water stations at intervals of 15 miles will meet 
 every requirement, while roads with a heavy traffic and 
 frequent trains may require them at every 5 or 6 miles. 
 
 They usually consist of large wooden tubs placed upon a 
 strong framework, supported by heavy pillars which rest 
 upon a foundation of masonry. The tubs are generally 
 circular in form, the bottom diameter being a few inches 
 larger than that of the top diameter, in order that the iron 
 hoops may drive tight. White pine, cedar, and redwood 
 are the varieties of timber principally used in the manufac- 
 ture of tanks. The staves are planed by machinery speci- 
 ally designed to give them the proper bevel, so that when 
 set up the joints are close and water-tight. The staves are 
 fastened together at the top with a single dowel between 
 each two, merely to hold them in place while being set up. 
 The pieces forming the bottom of the tank are doweled 
 together and fit into a groove about 1 inch in depth, 
 which is cut into the staves to receive them. The hoops 
 are fastened together with lugs which grip the two ends of 
 the hoop. The two lugs are united by a bolt threaded at 
 
RAILROAD STRUCTURES. 1276 
 
 both ends and fitted with nuts. By screwing up these nuts, 
 a strain is put upon the hoop. The hoops are first nearly 
 driven to place; the lugs are then tightened with a wrench, 
 after which the driving is finished. 
 
 Railroad water tanks hold from 20,000 to 40,000 gallons. 
 A common size is 16 ft. in diameter and IG ft. in height, 
 holding about 21,000 gallons. All tanks holding above 200 
 barrels are made from 3-in. stuff. This thickness is some- 
 what reduced by planing. The bottom of the tank should be 
 from 10 to 12 ft. above the tops of the rails. It is a com- 
 mon practice to enclose the tank in a framed structure, the 
 foundation and post supports forming the first story, and 
 the tank, together with its covering, the second story. 
 Where the supply of water is pumped, the first story is often 
 used as a pump house, and a fire is usually maintained in 
 winter to prevent the freezing of the water. At division or 
 terminal points, where many engines are to be supplied, the 
 tank is made proportionately larger, and often two are 
 placed together. 
 
 It is desirable to combine a coaling with a water station, 
 in order that an engine may take both fuel and water at the 
 same time. Such an arrangement is usually made at divi- 
 sion points and terminals, though it is not always practi- 
 cable to place a water tank and coaling station side by side. 
 
 A tender of coal will serve for several tankfuls of water, 
 so that coaling stations situated at division points, at inter- 
 vals of say 100 miles, will serve every requirement. 
 
 When the railroad has a double track, it is customary to 
 place a water tank on each side of the roadway, so that 
 engines may take water from either track. 
 
 The tank house should stand near the track, leaving only 
 from 2 to 4 feet clearance for cars. 
 
 1816. Source of Water Supply. — The least expen- 
 sive and most satisfactory water supply is that obtained 
 from either springs or brooks which have sufficient elevation 
 to deliver water into the tank by gravity and so avoid the 
 expense of pumping. Clear, pure water, as free as possible 
 
137r) RAILROAD STRUCTURES. 
 
 from mineral matter in solution, is greatly to be desired. If 
 the stream from which the supply is obtained is liable to be- 
 come muddy from freshets, a reservoir of suitable size should 
 be constructed and kept constantly full of clear water, so 
 that, in case of a freshet, the flow of the water into the 
 reservoir may be stopped until the stream runs clear. 
 
 Where spring water is used, and the supply in times of 
 drouth is liable to run short, a reservoir of ample capacity 
 should be constructed, and the surplus water stored for 
 future use. 
 
 When the source of supply is too low to be delivered by 
 force of gravity, resort is had to pumping. Formerly, horse- 
 power was used to a considerable extent for pumping, but of 
 late years steam and wind power have been exclusively em- 
 ployed. Pumping by wind mills is the least expensive, and, 
 but for occasional calms, the most satisfactory. The only 
 way to provide against a short supply due to calms is to make 
 the capacity of the water tanks adequate for a number of 
 days' supply. The tank has three pipes : an inlet pipe by 
 which the water enters the tank, a waste pipe for prevent- 
 ing overflow, and a discharge, or feed-pipe, 7 or 8 inches in 
 diameter, in or near the bottom, through which the water 
 flows to the tender tank. The discharge pipe is from 8 to 10 
 feet long, and jointed at the end which joins the tank, so 
 that when the tender tank is filled, the discharge pipe, acted 
 upon by a counterweight, swings either sideways or verti- 
 cally on its hinge joint, out of reach of the cars. The dis- 
 charge pipe at its connection with the tank is provided with 
 a valve which has a lifting gate. Movement is communica- 
 ted to this gate by means of a lever, the short arm of which 
 is attached to the valve rod. The long arm of the lever has 
 a rope attached, which hangs within reach of the engineman. 
 
 When taking water, the discharge pipe is lowered and 
 swung over the water hole in the tender tank. The engine- 
 man then pulls down on the lever. This action raises the 
 valve stem and allows the water to flow from the water tank 
 into the tender tank. Tender tanks hold from 2,500 to 3,500 
 gallons. 
 
RAILROAD STRUCTURES. 
 
 1277 
 
1278 RAILROAD STRUCTURES. 
 
 1817. Standard Water Titnks. — A general plan of 
 a standard water tank is given in Fig. ('/.VZ. The foundation 
 is shown in plan at A; a plan of the arrangement of timbers 
 composing the tank seat or deck is shown at /j, and a com- 
 plete elevation of the tank at C. The foundations should be 
 of the most substantial character, of well-dressed stone 
 laid in cement mortar. The foundation consists of either 
 continuous walls laid at right angles, upon which the sills 
 are placed and the posts mortised into them, or a pediment 
 of pyramidal form is built for each post, as shown in the 
 figure. Each ppst is secured to its pediment by a dowel 1 in. 
 in diameter by 6 in. in length. The stone pediment forms a 
 very substantial foundation. It is effective in appearance 
 and does away with the sills, which are apt to decay from 
 alternate wetting and drying. 
 
 The posts are connected together by girts a, d, c, which 
 are tenoned into the posts and fastened with treenails. This 
 connection is further strengthened by | in. tie-rods d, e,/, 
 which pass through each row of posts, a cast washer being 
 placed under the head and nut of each tie-rod. Between each 
 two rows of girts a series of X braces ^, //, k is placed and 
 securely spiked to the posts and girts. The caps /, w, n, o, 
 upon which the beams which compose the deck rest, are 
 12 in. X 12 in., and fastened to the posts by mortise and 
 tenon. The deck is composed of two sets of timbers laid at 
 right angles to each other. The first set, laid directly upon 
 the posts, are 3 in. X 12 in., and uniformly spaced. They are 
 held together and strengthened by bridging (see detail /?) 
 besides being spiked to the caps. The second set of deck 
 timbers are 4 in. X 6 in., and laid at right angles to the floor- 
 beams. They are spaced 19 in. center to center, and ex- 
 tend to within 3 in. of th6 tank staves. They are in direct 
 contact with the bottom of the tank, and receive the entire 
 weight of the water contained in the tank without allowing 
 any of its weight to rest upon the staves. The deck is usually 
 made octagonal in form, and where the tank is not covered 
 by a house, the deck is made to project far enough from the 
 tank (as shown at .£^) to protect the foundation and timber 
 
RAILROAD STRUCTURES. 
 
 1279 
 
 supports from the weather. The sides of the tank flare or 
 batter outwards at the rate of ^ in. to the foot, so that the 
 hoops will drive tight. 
 
 The discharge pipe/, when not in use, takes the position 
 shown in the figure, being held in that position by the 
 weighted ball ^, which is attached to the chain r, running 
 through the sheave s, and thence to its connection with the 
 discharge pipe. A cross-section of the track is shown at G, 
 the top of the rail being 12 ft. below the outlet of the 
 discharge pipe. 
 
 The valve connection of the discharge pipe with the tank 
 is shown in Fig. 633. The connection may be made either 
 
 Fig. 6.3.3. 
 
 through the side or bottom of the tank. The bottom valve 
 connection is shown in the figure. The valve rod a is 
 attached to the short arm of the lever d. The weight f , 
 attached to the end of the short arm of the lever, holds the 
 valve firmly in place. A rope is attached to the end d of the 
 long arm of the lever and hangs within reach of the engine- 
 man. By pulling down on this rope, the valve is raised, 
 and the water flows through the discharge pipe e to the 
 tender tank. The vacuum pipe / admits air to the discharge 
 
1280 
 
 RAILROAD STRUCTURES. 
 
 pipe after the valve comes to its seat, so that the discharge 
 pipe is quickly voided. 
 
 1818. Water Columns. — Where space is limited and 
 the head of water is sufficient, a water column (see Fig. 
 
 034) is used in place of 
 / W==^^'**ni a tank. One advantage 
 
 of a water column is in 
 its economy of space, 
 as will be at once ap- 
 parent. It can safely 
 be placed between the 
 parallel tracks of a 
 double-track road, and 
 serve engines on both 
 tracks equally well. 
 
 This water column 
 consists of a globe 
 valve a, connecting with 
 the main water pipe b^ 
 and enclosed in acham- 
 FiG. 634. ber of brick masonry. 
 
 This chamber is covered with a substantial floor of timber, and 
 forms the foundation for the pedestal c, which supports the 
 crane-shaped water 
 column d. This 
 column is jointed 
 at its connection 
 with the pedestal, so 
 that the discharge 
 pipe may be readily 
 swung over the ten- 
 der when taking 
 water. The cast- 
 iron globe f (Fig. 
 035) is connected 
 
 with the valve disk Fig. ess. 
 
 by means of the valve rod g^ and by its weight keeps the 
 
RAILROAD STRUCTURES. 1281 
 
 valve closed. When taking water, the lever h is de- 
 pressed. This causes the short arm k of the lever to 
 rise, and lifts the globe/". The weight being thus removed 
 from the valve, the disk is lifted by the pressure of the 
 water which flows through the discharge pipe to the tender 
 tank. 
 
 COALING STATIONS. 
 
 1819. Coaling stations are points along a railroad 
 where fuel is kept in stock for supplying locomotives. They 
 are placed at all division points, large yards, and sometimes 
 at the summits of long grades where pushers are employed. 
 Formerly, many roads used wood as fuel, but coal, which is 
 far more lasting and more economical of space, is now almost 
 universally used. The coaling stations of thirty years ago 
 were very primitive in design. The fuel was loaded by 
 hand, the coal being loaded into small carts and dumped 
 from a platform into the tender. A very decided advance 
 in design was made when the coal pockets shown in Fig. 
 636 were introduced. The pockets are supported on bents 
 of trestlework, each pocket comprising the space between 
 two bents. The figure shows the cross-section at A, and 
 the side elevation at B. Each bent is supported by four 
 posts, a, b, c, and d. All are vertical except the last, d^ 
 which has a batter of 3 in. to the foot. Timbers e f, 6 in. x 
 12 in., are bolted to both sides of the posts and supported 
 by batter posts ^, h, also 6 in. x 12 in., which are bolted to 
 both post and sill. These combined form the support to 
 the pocket floor system, which consists of 6 in. x 10 in. 
 floor-beams >^, /, etc., laid 2 ft. center to center, as shown 
 in the figure, and drift-bolted to the supports. Upon 
 these floor-beams is laid a flooring of 3-in. oak planks, 
 which are covered with plates of sheet iron from ^ to 
 y\ in. in thickness to protect them from the wear of the 
 coal. 
 
 The bents are spaced 12 feet, center to center, and 
 planked on both sides above the floor with 3-in. planks, 
 forming a series of pockets. This provides for storing coal 
 
1282 
 
 RAILROAD STRUCTURES. 
 
RAILROAD STRUCTURES. 1283 
 
 of different sizes, so as to meet the requirements of the dif- 
 ferent types of engines. The partition walls are also pro- 
 tected with sheet iron. The track stringers are placed 
 directly over the middle posts. They consist of two pieces 
 8 in. X 16 in., and extend over two bents, as in ordinary 
 trestle building. The ties are 7 in. X 8 in. X 10 ft., and 
 notched down 1 in. on the stringers. They carry an 8-in. 
 X 8-in. guard-rail, which is also notched 1 in. on the ties. 
 Stringers are fastened to cap with drift-bolts, | in. x 24 in , 
 round iron. Stringers are spaced 3 in., and held in place by 
 separators of cast iron. Stringer bolts are fin. X 22 in. 
 The bents are further tied together by the timbers ;//, w, 
 12 in. X 12 in., which are fastened to the caps with |-in. 
 X 20-in. drift-bolts, and by the timbers «, n. Gin. x 12 in., 
 which partly support the plank walks o. These walks are 
 protected by a railing / /, which is supported by posts 
 spiked to the timbers ///, ;//. 
 
 The coal is conducted from the pocket to tender by means 
 of the spout or chute r, composed of planks and sheet iron. 
 This chute, when in position for coaling a tender, is repre- 
 sented by r, and when not in use, by r' . It is fitted with 
 counterweights s, somewhat heavier than itself, which en- 
 able the engineman to handle it with ease. The mouth of 
 the pocket is closed by a sliding door /, of cast iron, which 
 works in guides, and is operated by means of a lever ti. 
 This lever is attached to a grooved wheel, in which works a 
 chain which is attached to the door /. The lever attach- 
 ment is shown in detail at C. The chain is fastened to the 
 groove of the wheel with a staple v. Power is applied to 
 the lever by means of the rope w. The wheel is supported 
 by two 4-in. X 12-in. oak timbers .r, x, which are bolted to 
 the plate y and the timber in. These are so fastened at the 
 top as to project forward, as shown at x in the elevation. 
 This throws the wheel axis forward, so that the lifting 
 chain will clear the woodwork. 
 
 To take coal, the engineman first lowers the spout r\ he 
 then pulls down the lever u by means of the rope u\ which 
 raises the door / and allows the coal to run from the pocket 
 
1284 RAILROAD STRUCTURES. 
 
 into the tender. The pocket floor at z should not be less 
 than 11 ft. above the top of the rail. 
 
 The loaded cars of coal are dumped directly from the 
 track above into the pockets. The supply track is usually 
 an incline plane, with a grade as sharp as is consistent with 
 safe operation. Sometimes, where space is very limited, the 
 loaded cars of coal are hauled to the top of the pockets by 
 cable over a steep incline. 
 
 1 820. A Modern Coaling Station. — A modern coal- 
 ing station is shown in Fig. 037, in which the coal is han- 
 dled by machinery. The figure includes a general plan of 
 the station, the elevation being shown at A and the cross- 
 section at B. The power to drive the machinery is fur- 
 nished by the engine c. The machinery consists of an ele- 
 vator d dzxiA a. conveyor e e, composed of link belts carrying 
 projecting pieces of board, which, as they slide through 
 troughs lined with sheet iron, form elevating or conveying 
 buckets, first elevating the coal from the pocket beneath the 
 track where it is dumped from the car, to the head of the 
 incline, and then conveying it to the different pockets, where 
 it is stored ready for the use of locomotives. The link belts 
 are driven by sprocket wheels 7^ and ^. The power is trans- 
 mitted from the engine to the machinery by means of a wire 
 rope belt. The main sheaves /i and k are 6 feet in diameter. 
 They are attached to shafts carrying pinions which drive the 
 gears /and ;//, and with them the sprocket wheels y and g: 
 The coal to be elevated to the coal pockets is first dumped 
 from the car ;/ into a chamber beneath the track. The coal 
 runs by gravity from this chamber through the opening 
 into the elevating chute /, which is lined with sheet iron, 
 and as the projecting boards carried by the link belt pass 
 under the sprocket wheel g, they push the coal before them, 
 forming a series of buckets, which carry the coal to the point 
 r, where an opening in the chute allows the coal to fall into 
 the conveying chute s. Here a similar series of buckets, 
 passing around the sprocket wheel /, collects the coal as it 
 falls from the elevator chute and carries it to the storage 
 
'/ /// / . ',/l/l,l/' 
 
'-////////////////////// 
 
 *55m^^;mm#.^M;^^^i^Ml:^^^^^f^^, 
 
RAILROAD STRUCTURES. 1285 
 
 pockets of the station. In the bottom of the conveying 
 chute, and directly above each pocket, is an opening of suit- 
 able dimensions. These openings are fitted with sliding 
 covers, which are close fitting, and all of them are closed 
 excepting the one connecting with the pocket to be filled. 
 The sheave ii is fitted with a sliding journal which provides 
 for taking up any slack in the wire rope drive due to stretch- 
 ing. The link belt of the elevator on its return is supported 
 by the sheaves v and w, and the conveyor belt by the sheave 
 X. These sheaves are supported by brackets bolted to the 
 floor timbers of the chutes. The pockets are enclosed with 
 planks and covered by a slate roof, an open space 2 feet in 
 width being left under the eaves for the free circulation of 
 air. The general form of the coal pockets is the same as 
 those shown in Fig. 636. The coaling spouts j, y are made 
 of cast iron, instead of plank lined with sheet iron. The 
 spouts are raised and lowered by means of counterweights^ 
 as shown both in elevation and cross-section. The pockets 
 are lined with sheet iron or steel. The gauge line of the 
 track is commonly placed 5 ft. from the face of the coal 
 pockets, and the bottom of the pockets at their connection 
 with the spouts 12 ft. above the rail. 
 
 TURNTABLES. 
 1821. A turntable, as shown in Fig, 638, is a platform 
 usually from 50 to 70 feet long, and from 8 to 10 feet wide, 
 upon which a locomotive and tender may be run and then 
 turned horizontally through any portion of a circle, and thus 
 be transferred from one track to another forming any angle 
 with it. The table is supported by a pivot under its cen- 
 ter, and by wheels or rollers under its ends. Beneath the 
 platform is excavated a circular pit 4 or 5 feet deep, having 
 its circumference lined with brick or stone masonry 2 feet 
 in depth, and capped with either cut stone or wood. The 
 diameter of the pit in the clear is about 2 inches greater 
 than the length of the turntable. The masonry lining is 
 usually built with a step (see elevation B), which supports 
 
1286 
 
 RAILROAD STRUCTURES. 
 
 i2/. 
 
RAILROAD STRUCTURES. 1287 
 
 the rail upon which the end rollers travel. At the cen- 
 ter of the pit is a substantial foundation of masonry, 
 upon which the pivot rests. This foundation should be 
 4 or 5 feet in depth and composed of large, regularly 
 shaped stones laid in cement mortar and well bonded to- 
 gether. This foundation is capped by a single stone 6 ft. 
 square and 12 in. in thickness. The pivot, shown in de- 
 tail at C, is fastened to the foundation by heavy anchor 
 bolts reaching the full depth of the masonry. Sometimes 
 the pit is floored over with plank, but this so greatly in- 
 creases the weight of the table, besides involving the ex- 
 pense of renewal, that it should be dispensed with unless 
 circumstances make a floor necessary. Usually, only a 
 walk of planks, supported by the projecting ties, is al- 
 lowed. 
 
 The turntable should be somewhat longer than the total 
 lengch of both locomotive and tender, so as to permit the 
 engineman to move his engine a few feet in either direction 
 from the pivot in order to secure an equilibrium. With a 
 little practice, such an equilibrium is easily obtained. By 
 this means the friction while turning is confined chiefly to 
 the center of motion. 
 
 Probably the best turntables in use in America are manu- 
 factured by Wm. Sellers & Co., of Philadelphia, Pa. 
 The turntable shown in Fig. 638 is a copy of their recent 
 standard. They are expensive in first cost, but most 
 economical both in operation and in the matter of repairs. 
 Being composed chiefly of metal they are very enduring, 
 and as the parts are readily duplicated, repairs are simple 
 and expeditious. One man can readily turn one of these 
 tables, loaded, without the assistance of machinery. They 
 consist of two heavy cast-iron girders, perforated by circu- 
 lar holes to reduce weight and cost. Each girder consists 
 of two parts, a and b, fastened to a heavy central boxing, 
 shown in cross-section at C. 
 
 The girders are fastened to it by means of heavy iron 
 bars c, d, 3J in. square, of rolled iron, fitted into sunk 
 recesses on top of the boxing, and tightened in place by 
 
1288 RAILROAD STRUCTURES. 
 
 means of wedges, and also by means of two 2:J:-in. key bolts 
 at the base of the girders, passing through the holes r, /, 
 and confined by the keys^, ^. The central portion of the 
 boxing is a hollow cone ^, open at top and bottom, and sur- 
 rounding the hollow conical pivot post I'. The pivot shell 
 is about If in. thick. On top of the post rests a heavy, 
 loose, cast-iron cap /, which permits of a slight rocking motion 
 of the entire platform as the engine enters and leaves the 
 turntable. This cap supports the steel box (see detail D) 
 containing the friction rollers w. There are fifteen 
 of them, each about 2f in., both in length and greatest 
 diameter. They have no axles, but lie loosely in the lower 
 part of the box, filling its circumference, save a half-inch of 
 space left for the free movement of the rollers. In the 
 direction of their axis they have but ^ in. play in the box. 
 The lid « of the box rests directly upon the rollers them- 
 selves, and does not come down to the lower part o of the 
 box by ^ inch. Both the rollers and the box enclosing them 
 are finished with mathematical accuracy, so as to ensure a 
 perfect bearing between them. The rollers are kept con- 
 stantly oiled, as ease in turning depends entirely upon their 
 being well lubricated. On top of the rollers is the cap/, 
 which is secured by heavy bolts. This cap does not rest 
 directly upon the boxing, but is separated from it by wooden 
 wedges g, q, by means of which the table may be raised or 
 lowered and its height exactly adjusted to the connecting 
 track. 
 
 When the engine is properly balanced, the cap bolts sus- 
 tain all the load placed upon the turntable, excepting the 
 small amount carried by the tracks at the end of the 
 platform. 
 
 When properly balanced on a Sellers' turntable, the end 
 wheels should only just touch the rails. The diameter 
 of the roller box being 15 in., it is not difficult to balance 
 the locomotive and tender. All turntables should be pro- 
 vided with the means of being raised -or lowered, and so 
 adjusted as to give the proper bearing upon the circular 
 track. 
 
0-2^^-2 -nopuijf 
 
 $c-fn»tjtis ptia 
 
1290 RAILROAD STRUCTURES. 
 
 SECTION BUILDINGS. 
 
 1822. Tool Houses. — At the headquarters of each 
 section a tool house is erected for the storage of hand and 
 push cars, track tools, and all track materials which may be 
 damaged by exposure to the weather, or, on account of 
 their portability, likely to be stolen. Among the latter 
 class are track bolts and track spikes, nails and cut spikes, 
 shim and pin timber, etc. The tool house should not con- 
 nect directly with the main track, but with a siding, so that 
 a train standing on the main track will not interfere with a 
 crew starting for work with either hand or push car. The 
 tool house should be placed convenient to that occupied by 
 the section foreman, so that all tools and material may be 
 near his hand either for repair or inspection, or for use in 
 case of an emergency. All tools and material contained in 
 the house should be kept in perfect order and repair. A 
 building fully meeting the requirements of a tool house is 
 shown in Fig. 639. It should rest upon a substantial found- 
 ation of masonry, and stand fully 12 inches above the sur- 
 face of the ground, so as to allow ample circulation of air 
 among the floor timbers. At one end of the house is a 
 work bench fitted with a vise, together with wrenches, ham- 
 mers, hand saws, punches, and any other tools necessary in 
 making repairs of tools or track. 
 
 The hand and push cars rest upon a permanent track, 
 shown at a. They are admitted through a sliding door 
 shown in detail at A. 
 
 A device for transferring the hand car to the tool house 
 track is shown at C. It consists of two oak pieces b and c 
 which serve as rails. They are held at gauge by the cross- 
 piece d and the bolster e, which are bolted to the strips. A 
 pin passes through the bolster ^ into a socket in the cast-iron 
 portable pedestal /"on which the frame revolves. In using, 
 the pedestal is placed upon a tie with the pieces r, d lying di- 
 rectly upon the rails. The hand car is then run upon the frame, 
 which is revolved so as to connect with the tool house track. 
 
 The tool house should be well provided with racks, upon 
 which the various tools of the section may be safely and 
 

 
 
 
 
 
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 FlO 640 
 
1292 RAILROAD STRUCTURES. 
 
 economically stored. Hooks of iron or of wood nailed to the 
 sides of the house are especially handy for hanging up 
 shovels. A locker built under the work bench is useful for 
 storing lanterns and oil cans. 
 
 The plan shown is in detail, so that it may be used as a 
 guide for any who wish to build a safe and economical tool 
 house. A section through the door is shown in detail at B. 
 The roof covering is of corrugated iron, which also serves as 
 a protection against fire. 
 
 1823* Section Dwelling Houses. — Dwelling houses 
 for section men should be substantial, neat, and of moderate 
 size and cost. A house meeting these requirements is shown 
 in Figs. G40 and 641. It has a balloon frame, is strong, 
 and may be undertaken and built by any carpenter of aver- 
 age intelligence. It provides ample accommodation for a 
 family of eight persons, and will contain twelve with but 
 little crowding. The outer walls and partitions consist of 
 two courses of inch boards nailed vertically to the frame. 
 They should be surfaced on one side, ship lapped, and 
 well seasoned before being put in place. This gives a 
 smooth surface on both sides of the walls, and takes paint 
 well. 
 
 Door and window casings should be of pine. The ground 
 floor is of material similar to the walls, excepting that the 
 floor boards should be tongued and grooved. Complete 
 framing plans are shown, and will serve as a guide to those 
 undertaking similar work. The cross-section A B shows 
 the arrangement of the stairs and spacing of floors. A 
 framing plan of the second floor is shown at E^ and of the 
 first or ground floor at G. A detail of the roof frame of 
 the main body of the house is shown at F^ and of the roof 
 of the addition at H. A detail of the sill and floor joist is 
 shown at A', and of a door casing at L. The roof covering, 
 like that of the tool house, should be of corrugated iron. 
 
 1824. "Watchman's Shanty. — A watchman's shanty 
 should be large enough to comfortably accommodate one 
 man, no more. This will include space for a stove for warming 
 
Section through AB. 
 
 Section through CD. 
 
 Fig. Ml. 
 
1294 RAILROAD STRUCTURES. 
 
 the building in winter. A general plan for a watchman's 
 
 h' 
 
 r 
 
 i'xo' 1 
 
 > 
 
 s'xr 
 
 V 
 
 1 
 
 1 
 2x4' - 
 
 
 < r 
 
 sxe' 
 
 1 
 
 
 U 1 
 
 
 8'xs: 
 
 
 
 
 frtndow 
 Ugh U 8x10 
 
 
 
 
 
 
 
 1 
 
 rlx«" fi 
 
 1 - '^ 
 1 ^«xa^ 
 
 
 
 B * M 1 
 
 
 
 ■ 3x« ■ 
 
 
 1 
 
 
 .L 
 
 I 
 
 ,^ ir«w<l»«cr. I ^ 
 
 i^ax*" 
 
 Fig 642. 
 
 shanty is given in Fig. G42, which is sufficiently detailed for 
 practical use. 
 
A SERIES 
 
 OF 
 
 QUESTIONS AND EXAMPLES 
 
 Relating to the Subjects 
 Treated of in Vol. II, 
 
 It will be noticed that, although the various questions 
 are numbered in sequence from 614 to 1082, inclusive, these 
 questions are divided into seven different sections, corre- 
 sponding to the seven sections of the preceding pages of this 
 volume. Under the heading of each section are given, in 
 parentheses, the numbers of those articles which should be 
 carefully studied before attempting to answer any question 
 or to solve any example occurring in the section. 
 
SURVEYING, 
 
 (ARTS. 1180-1308.) 
 
 Note. — The examples given in this subject are similar to those 
 arising in field and office practice, and the answers given have the 
 same degree of accuracy as required in practical operations. When 
 the answer contains a decimal fraction, the student should carry out 
 the result to one place greater than required in the answer given. 
 If the figure so obtained is less than 5, it is ignored; if it is 5 or 
 greater, add 1 to the preceding figure for the correct answer. 
 
 (614) In a triangle whose angles are A, B, and C, what is 
 each angle if A is twice and B three times C ? 
 
 (615) Required, each angle of an isosceles triangle, if the 
 unequal angle equals twice the sum of the other two. 
 
 (616) Construct a square whose diagonal is 3.5 inches. 
 What is the length of its side ? Ans. 2.475 in., nearly. 
 
 (617) The diagonal of a rectangle is 3 inches, the shorter 
 side 1.5 inches; construct it and fitnd its area. 
 
 Ans. Area = 3.897 in. 
 
 (618) Through two points 1.5 inches apart, draw a circle 
 having a diameter of 3.5 inches. 
 
 (619) At any point on a straight line, construct an angle 
 of 30°. 
 
 (620) A line 2 inches long is met at one extremity by a 
 second line, making with it an angle of 30° ; find the center 
 of the circle of which the first is a chord and the second 
 a tangent. 
 
 (621) At a point on any straight line construct an angle 
 of 45°. 
 
 (622) Construct an isosceles triangle with a base of 3 
 inches and a vertical angle of 00°. 
 
 (623) Draw a figure showing two parallel lines cut by a 
 secant, and name all the angles thus formed. 
 
1298 SURVEYING. 
 
 (624) What is meant by similar polygons ? Give exam- 
 ples. 
 
 (G25) One of the angles of a triangle is 30°; one of the 
 including sides 5 inches, and the difference of the other two 
 sides 1.5 inches; construct the triangle. 
 
 (G2G) How is the north end of the magnetic needle 
 determined ? 
 
 (627) How is the compass circle divided, and how are the 
 degrees numbered ? 
 
 (628) Explain why the east and west points of the com- 
 pass plate are marked the reverse of their natural order. 
 
 (629) What are the principal defects of the compass ? 
 
 (630) What constitutes a course ? 
 
 (631) How is the bearing of a line taken and how 
 checked ? 
 
 (632) How is a line run by backsights ? 
 
 (633) Define local attraction and state by what it is 
 usually caused. 
 
 (634) Explain the difference between the magnetic 
 meridian and a true meridian. 
 
 (635) What is meant by the declination of the needle ? 
 
 (636) How is a true meridian established ? 
 
 (637) Explain the difference between a magnetic bearing 
 and a true bearing. 
 
 (638) {a) The declination is 3° 15' east; what are the 
 true bearings of the following lines, their magnetic bearings 
 being : 
 
 Magnetic Bear- 
 ing. 
 
 True 
 Bearing. 
 
 N 15° .20' E 
 
 
 N 88° 50' E 
 
 
 N 20° 40' W 
 
 
 N 50° 20' E 
 
 
SURVEYING. 
 
 1299 
 
 {d) The declination is 5° 10' west; required, the true 
 bearing of the following lines: 
 
 Magnetic Bear- 
 ing. 
 
 True 
 Bearing. 
 
 N 7°20'W 
 
 
 N 45° 00' E 
 
 
 S 15° 20' E 
 
 
 S 2° 30' W 
 
 
 (639) How are stations in railroad surveys numbered, 
 and what is the interval between stations ? 
 
 (640) What are the special advantages which the com- 
 pass offers in preliminary railroad surveys, and what 
 conditions should determine its rejection for such work ? 
 
 (641) Describe the process of chaining. 
 
 (642) Plat the following compass notes: 
 
 Station. 
 
 Bearing. 
 
 60 + 20 
 
 
 50 + 90 
 
 N 80° 15' E 
 
 44 + 50 
 
 S45° 55' E 
 
 28 + 13 
 
 S11°25'E 
 
 20+11 
 
 S 76° 30' E 
 
 10 + 89 
 
 N79° 25' E 
 
 5 + 20 
 
 N 40° 50' E 
 
 
 
 N 10° 10' E 
 
 (643) Describe the vernier. A vernier is described as 
 reading to single minutes. Make a drawing of such a 
 vernier and explain its use. 
 
 (644) Explain the different adjustments. 
 
1300 
 
 SURVEYING. 
 
 (645) How is a line prolonged by backsight ? by 
 foresight ? 
 
 (646) Explain by figure the process of double centering, 
 and state its advantages, 
 
 (647) Define a horizontal angle and its measurement. 
 
 (648) Of what value is the magnetic needle where all 
 angles are read with the vernier ? 
 
 (649) Explain by example what is meant by calculated 
 or deduced bearings. 
 
 (650) The magnetic bearing of a line is N 55° 15' E, and 
 an angle of 15° 17' is turned to the right; what is the 
 bearing of the second line ? \ 
 
 (651) The magnetic bearing of a line is N 80° 11' E, and 
 an angle of 22° 13' is turned to the right; what is the 
 bearing of the second line ? 
 
 (652) The magnetic bearing of a line is N 13° 15' W, and 
 an angle of 40° 20' is turned to the left; what is the bearing 
 of the second line ? 
 
 (653) 
 
 Station. 
 
 Deflection. 
 
 Mag. Bearing. 
 
 Ded. Bearing. 
 
 54 + 25 
 
 
 
 
 49 + 20 
 
 L. 25° 14' 
 
 S 25° 40' W 
 
 
 44 + 80 
 
 L. 10° 47' 
 
 S 50° 50' W 
 
 
 33 + 77 
 
 R. 16° 55' 
 
 S 61° 45' W 
 
 
 . 25 + 60 
 
 R. 24° 40' 
 
 S 44° 50' W 
 
 
 16 + 20 
 
 L. 15° 35' 
 
 S 20° 00' W 
 
 
 8 + 90 
 
 R. 10° 15' 
 
 S 35° 50' W 
 
 
 4 + 40 
 
 R. 15° 10' 
 
 S 25° 20' W 
 
 
 
 
 
 S 10° 15' W 
 
 
SURVEYING. 
 
 1301 
 
 Calculate the bearings of the foregoing transit notes of an 
 angle line and plat them to a scale of 400 feet to the inch, 
 showing the direction of the magnetic meridian. 
 
 (654) The line of survey A B 
 (see Fig. 12) crosses a stream 
 C D too wide for direct meas- 
 urement. The angle A is 80° 
 20', the angle E is 60° 15', 
 the side A E \^ 415 feet ; re- 
 quired, the angle B and the 
 side A B. 
 
 Angle B = 39° 25'. 
 
 Side ^i?= 567.44 ft. 
 
 Ans. 
 
 (655) 
 
 Pig. 12. 
 
 An obstacle. Fig. 13, lies in the path of survey 
 A B. Show how the equilat- 
 eral triangle may be used in 
 passing the object and prolong- 
 ing the line of survey. 
 
 Fig. 13. 
 
 (656) What is an intersec- 
 tion of tangents ? How is it 
 made and the angle of intersection measured ? 
 
 (657) Define curve and tangent as applied to railroad 
 engineering. 
 
 (658) Name and describe the three classes of curves used 
 in railroad building. 
 
 (659) What is the amount of the divergence of two lines 
 100 feet in length and forming an angle of 1° with each 
 other ? 
 
 (660) What is the unit curve employed in railroad 
 building ? Define it. 
 
 (661) Define a five-degree (5°) curve. 
 
 (662) What is the ratio of the degree of curve to the 
 deflection angle ? 
 
1303 
 
 SURVEYING. 
 
 (GG3) What is the formula for finding the radius^ the 
 
 deflection angle be- 
 ing given ? 
 
 (664) What is the 
 formula for finding 
 the length of any 
 chord, the radius 
 and deflection angle 
 being given ? 
 
 (GG5) What is the 
 tangent distance, 
 and what formula is 
 used in finding it ? 
 
 (666) The tan- 
 FiG. 14. gents A ^ and C D, 
 
 in Fig. 14, intersect at some inaccessible point E. The angle 
 A is 22° 10', the angle C 23° 15', and the side A C 253.4 
 feet ; required the angle of intersection C E /% and the sides 
 A EznA E C. ( Angle CEE= 45° 25'. 
 
 Ans. ] Side A E = 140.44 ft., nearly. 
 ( Side CE= 134.24 ft., nearly. 
 
 (667) The angle of intersection of two tangents is 35° 10' ; 
 the degree of curve is G° 15'; what is the tangent distance ? 
 
 Ans. 290. GG ft., nearly. 
 
 (668) The angle of intersection is 14° 12' ; the degree of 
 curve, 3° 15'; what is the tangent distance ? 
 
 Ans. 219.62 feet. 
 How is the length of curve found ? 
 The angle of intersection is 30° 45'; the degree of 
 15'; what is the length of the curve ? 
 
 Ans. 585.71 feet. 
 The angle of intersection is 33° 06' ; the station of 
 the point of intersection, 20 -p 37.8; the degree of curve, 
 5°; what is the station of the P. C, length of curve and 
 station of the P. T. ? t P. C. = 16 + 97. 17. 
 
 Ans. ■) Length of curve = 662 ft. 
 ( P. T. =23 + 59.17. 
 
 (669) 
 
 (670) 
 
 curve, 5*^ 
 
 (671) 
 
SURVEYING. 130:i 
 
 (072) The angle of intersection is 20** 10'; the tangent 
 distance, 291. IG feet ; required, the radius and degree of curve. 
 
 ^^^ j Radius = 1,(;:57. 29 feet. 
 I Degree of curve, 3° 30'. 
 
 (673) What is the formula for the chord deflection ? 
 
 (074) What is the ratio of the chord deflection to the 
 tangent deflection ? 
 
 (675) The degree of curve is 7°; what is the deflection 
 angle for a chord of 48.2 feet ? Ans. 1" 41.22'. 
 
 (676) The degree of curve is 6° 15' ; what is the deflection 
 angle for a chord of 72.7 feet ? Ans. 2° 16.3'. 
 
 (677) The degree of curve is 5° 30' ; what is the tangent 
 deflection, or offset, for 50 feet ? Ans. 1.199 feet. 
 
 (678) The degree of curve is 4° 15' ; what is the chord 
 deflection for 35.2 feet ? Ans. 0.919 foot. 
 
 (679) What is the radius of a 3° 10' curve ? 
 
 Ans. 1,809.57 feet. 
 
 (680) Two lines of equal length forming an angle of 1° 
 with each other diverge 18.22 feet; what are the lengths of 
 the lines? . j By trigonometry, 1,043.53 feet. 
 
 ( By practical method, 1,044.13 feet. 
 
 (681) A curve is 606.25 feet in length; the angle of inter- 
 section is 24° 15' ; what is the degree of the curve ? 
 
 Ans. 4°. 
 
 (682) What are the different processes of leveling ? 
 Define them. 
 
 (683) Describe the Y level and explain its adjustments. 
 
 (684) The level rod is held 300 feet from the instrument; 
 the reading is 6.81 feet. After causing the level bubble to 
 move over one division of the scale, the reading is 6.84; 
 what is the radius of the bubble tube ? Ans. 100 feet. 
 
 (685) What is meant by the power and definition of a 
 telescope ? 
 
1304 SURVEYING. 
 
 (G8G) Describe the self-reading leveling rod. 
 
 (687) The elevation of the point where the backsight is 
 taken is 61.84 feet, the backsight is 11.81 feet, and the fore- 
 sight to a turning point (T. P.) is 0.49 foot; what is the 
 elevation of the T. P. ? Ans. 73. 16 feet. 
 
 (688) Define a datum line. 
 
 (689) What are turning points ? 
 
 (690) What are bench marks ? 
 
 (691) What are the principal sources of error in taking 
 levels ? 
 
 (692) Explain the process of checking level notes. 
 
 (693) What is a profile ? 
 
 (694) Define a 1 per cent, grade. 
 
 (695) The elevation of the grade at Station GO is 126.50; 
 between Stations 66 and 100 there is an ascending grade 
 of 1.25 per cent.; what is the elevation of the grade at 
 Station 93 ? Ans. 160.25 feet. 
 
 (696) What is topographical surveying ? 
 
 (697) The elevation of a station is 56.5 feet; the ground 
 on the left falls 10.3 feet in a distance of 73 feet, where the 
 slope changes, giving a fall of 16.4 feet in a distance of 56 
 feet. On the right the ground rises 11.4 feet in a distance 
 of 84 feet, where the slope changes, giving a rise of 8.8 
 feet in a distance of 96 feet. How are these slopes recorded 
 in the topographer's book ? How many 10-foot contours 
 are included by the side slopes, and what are their eleva- 
 tions, the contours being placed at even decimal intervals 
 of 10 feet ? What are the several distances of the contours 
 from the center line ? 
 
 (698) Work out the elevation of the following notes; 
 check the notes, plat them in a profile, and draw a descend- 
 ing grade line of 80 feet to the mile, and place in the 
 
SURVEYING. 
 
 1:^05 
 
 column headed Grade the elevation of the grade of each 
 station given in the station column: 
 
 Station. 
 
 Rod 
 Read- 
 ing. 
 
 Ht. 
 Instru- 
 ment. 
 
 Eleva- 
 tion. 
 
 Grade. 
 
 Remarks. 
 
 B.M.+5.53 
 
 
 
 101.42 
 
 
 B M. on Poplar tree 10 ft. 
 left; Sta. 40. 
 
 40 
 
 G.4 
 
 
 
 162.0 
 
 
 41 
 
 7.2 
 
 
 
 
 
 41 + 60 
 
 10.9 
 
 
 
 
 
 42 
 
 8.6 
 
 
 
 
 
 43 
 
 8.8 
 
 
 
 
 
 T. P. - 
 
 8.66 
 
 
 
 
 
 + 
 
 2.22 
 
 
 
 
 
 44 
 
 4.8 
 
 
 
 
 
 45 
 
 6.3 
 
 
 
 
 
 46 
 
 8.8 
 
 
 
 
 
 47 
 
 9.9 
 
 
 
 
 
 48 
 
 11.1 
 
 
 
 
 
 T. P. - 
 
 11.24 
 
 
 
 
 
 + 
 
 3.30 
 
 
 
 
 
 49 
 
 4.7 
 
 
 
 
 
 50 
 
 7.1 
 
 
 
 
 
 51 
 
 8.7 
 
 
 
 
 
 52 
 
 9.8 
 
 
 
 
 
 53 
 
 10.9 
 
 
 
 
 
 T. P.- 
 
 11.62 
 
 
 
 
 
 (699) The ground to the right of the center line has an 
 ascending slope of 11° for a distance of 120 feet, and to 
 
130G 
 
 SURVEYING. 
 
 the left of the center line a descending slope of 9*^ for a 
 distance of 117 feet, where the slope changes to a descend- 
 ing slope of 0° for a distance of G5 feet; how are the slopes 
 recorded in the topographer's book ? If the elevation of 
 the ground at the center line is 75.0 feet, how many 
 5-foot contours are included by the given slopes, and what 
 are their respective distances from the center line ? 
 
 (700) The-angle of slope is 3° ; what is the horizontal 
 distance for a rise of 10 feet ? 
 
 (701) An instrument is stationed at A, Fig. 15, 100 feet 
 from the base of a church spire B C. The horizontal line 
 
 Fig. 16. 
 
 of sight vi C from the instrument is 5 feet above the base 
 of the spire, which at that point is 30 feet in diameter. 
 The angle C A B is 45* 20'; required, the height of the 
 spire. Ans. 121.345 feet. 
 
 (702) The height of barometer // at lower station is 
 
SURVEYING. 1307 
 
 29.40 in. ; the temperature / = T4''; the height of barometer 
 H at the higher station is 20.05 in., and the temperature 
 /' = 58° ; what is the difference in elevation ? 
 
 Ans. 2,454 feet. 
 
 (703) What is hydrographic surveying ? 
 
 (704) What stage of tide is the basis tor all soundings ? 
 
 (705) What is a tide gauge ? 
 
LAND SURVEYING. 
 
 (ARTS. 1309-1344.) 
 
 (706) What are the names of the general divisions into 
 which the public lands of the United States are divided ? 
 
 (707) Give the dimensions and contents of each. 
 
 (708) {a) Define a Principal Meridian, (d) How is it 
 established .'' (c) What boundaries are marked on it ? 
 
 (700) What causes convergency of meridians^ and what 
 effect does such convergency have upon the boundary lines 
 of the Government surveys ? 
 
 (710) {a) What are Standard Parallels ? {b) What is 
 their object ? (r) What boundaries are marked on them ? 
 
 (711) How are townships described with reference to 
 Base Line and Principal Meridian ? Illustrate by a 
 diagram. 
 
 (712) Show by a diagram how township lines are run and 
 the order of the survey. 
 
 (713) Explain by figure the terms random line and true 
 line. 
 
 (714) How are excesses or deficiencies of measurement 
 disposed of in townshiping and sectioning ? 
 
 (715) Show by a diagram the subdivisions of townships 
 and the order of survey. 
 
 (71G) {a) Define vicandcring as applied to Government 
 surveys, {b) In mapping, what use is made of meander 
 lines ? (f) How are islands located ? 
 
 (717) What is a line tree, how is it marked, and how are 
 trees on either side' of the line of survey marked ? 
 
1310 
 
 LAND SURVEYING. 
 
 (718) How is a boundary corner in a timbered country 
 marked ? 
 
 (719) Describe the township corner-post or corner-stone. 
 How is it set, and how marked ? 
 
 (720) Describe a section corner, and explain how it is set 
 and marked. 
 
 (721) How are mound corners constructed ? 
 
 (722) What are double corners^ where are they found, 
 and how are they designated ? 
 
 (723) In running township and section lines, "what 
 account should the surveyor take of the topography of the 
 country ? 
 
 (724) What are the various field books used in the survey 
 of Government lands ? 
 
 (725) State why the retracing of old lines or original 
 surveys is so difficult. 
 
 (72G) Suppose the original notes of a farm survey are 
 the following, and suppose that only two of the original 
 
 - corners, viz., B and C^ re- 
 
 Stations. 
 
 A 
 B 
 C 
 D 
 
 Bearings. 
 
 N 3ir W 
 N 62° E 
 S 36° E 
 
 S 45r w 
 
 Distances. 
 
 main, and that we find the 
 
 ~Zr, ~. present bearing from B to C 
 10.4 chains. *^ ° 
 
 9.2 chains. ^^ ^ ^^ ^^ ^' ^^^ "^^X ^^ 
 
 7.6 chains, determine the magnetic vari- 
 
 10.0 chains, ation, and what will be the 
 
 • = corrected bearings by which 
 
 we may restore the original boundaries ? 
 
 (727) How are boundary lines straightened and new 
 corners established where old ones are obliterated ? 
 
 (728) What are witness trees, and how are they marked ? 
 (720) Explain by a figure the triangular method of 
 
 calculating areas. 
 
 (730) Explain by a figure the trapezoidal method of 
 calculating areas. 
 
 (731) Define {a) the latitude of a point; {b) the longi- 
 
LAND SURVEYING. 
 
 1311 
 
 tude of a point; (c) the latitude of a line, and {d) the 
 departure of a line. 
 
 (732) The line A B, in Fig. IG, has a bearing of N 30° E 
 and a length of 187 ft. Complete the figure, 
 showing the latitude and departure of A B, 
 and calculate their respective lengths by means 
 of a table of sines and cosines. 
 
 (733) Describe a traverse table. 
 
 (734) The bearing of a line is N 23^° E ; 
 its length is 423 ft. ; calculate its latitude and 
 departure by the use of a traverse table, and 
 explain the process. 
 
 (735) The length of a line is 225 ft. ; its 
 bearing is 40° ; what are the latitude and de- 
 parture of the line, and what is the relation 
 of that latitude and departure to the latitude and departure 
 of the complement of the given bearing ? 
 
 (736) How are latitudes and departures applied in testing 
 the accuracy of a survey ? 
 
 (737) 
 
 Fig. 16. 
 
 Stations. 
 
 Bearings. 
 
 Distances. 
 
 1 
 
 N 31i° W 
 
 10.40 chains. 
 
 2 
 
 N62° E 
 
 9.20 chains. 
 
 3 
 
 S 36° E 
 
 7.60 chains. 
 
 4 
 
 S 45i° W 
 
 10.00 chains. 
 
 Calculate the latitudes and 
 departures of the courses 
 in the accompanying ex- 
 ample, and balance them, 
 giving all the steps of the 
 process. 
 
 (738) Calculate the total latitudes and departures from 
 Station 2, and from them make a plat of the survey 
 explaining the different steps in the process, , 
 
 (739) What is the longitude of a line ? 
 
 (740) What is the general rule for the double longitude of 
 any course of a given survey ? 
 
 (741) Illustrate by a figure the method of computing areas 
 by double longitudes. 
 
 (742) What are north products and what south products ? 
 
1312 
 
 LAND SURVEYING. 
 
 (743) If the double longitude is negative and the corre- 
 sponding latitude positive, is the product north or south ? 
 
 (744) How is the most easterly or most westerly station 
 of a survey found ? 
 
 (745) 
 
 (740) 
 
 (747) 
 
 Distances. 
 
 12.41 chains. 
 5.86 chains. 
 8.25 chains. 
 4.24 chains. 
 
 Stations. 
 
 Bearings. 
 
 Distances. 
 
 1 
 
 S 21i° 
 
 W 
 
 17.62 chains. 
 
 2 
 
 S 34° 
 
 w 
 
 10.00 chains. 
 
 3 
 
 N56° 
 
 w 
 
 14.15 chains. 
 
 4 
 
 N34° 
 
 E 
 
 9.76 chains. 
 
 5 
 
 N67° 
 
 E 
 
 2.30 chains. 
 
 6 
 
 N23° 
 
 E 
 
 7.03 chains. 
 
 7 
 
 NlSr 
 
 E 
 
 4.43 chains. 
 
 8 
 
 S 76i° 
 
 E 
 
 12.41 chains. 
 
 Stations. 
 
 Bearings. 
 
 Distances. 
 
 1 
 
 N 
 
 18i" 
 
 E 
 
 1.93 chains. 
 
 2 
 
 N 
 
 9° 
 
 W 
 
 1.29 chains. 
 
 3 
 
 N 
 
 14' 
 
 W 
 
 2.71 chains. 
 
 4 
 
 N 
 
 74° 
 
 E 
 
 0.95 chains. 
 
 5 
 
 S 
 
 48i° 
 
 E 
 
 1.59 chains. 
 
 6 
 
 S 
 
 14i' 
 
 E 
 
 1.14 chains. 
 
 < 
 
 s 
 
 i9r 
 
 E 
 
 2.15 chains. 
 
 8 
 
 s 
 
 23i° 
 
 W 
 
 1.22 chains. 
 
 9 
 
 s 
 
 5° 
 
 W 
 
 1.40 chains. 
 
 10 
 
 s 
 
 .30' 
 
 W 
 
 1.02 chains. 
 
 11 
 
 s 
 
 8ir 
 
 W 
 
 0.69 chains. 
 
 12 
 
 N 
 
 32r 
 
 W 
 
 1.98 chains. 
 
 Find the area by double 
 longitudes, giving all the 
 intermediate steps. 
 
 Ans. 4 A. 2 R. 35.8 P. 
 
 Find area by double longi- 
 tudes. 
 
 Ans. 33 A. OR. 8.8 P. 
 
 Find area by double longi- 
 tudes. 
 
 Ans. 1 A. 1 R. 27| P. 
 
LAND SURVEYING. 1313 
 
 (748) In laying out town sites, what matters should first 
 be considered ? 
 
 (749) (a) How should the grades of streets be arranged 
 with reference to drainage ? (d) with reference to topog- 
 raphy ? 
 
 (750) How should dase lines be located with reference to 
 railroad lines ? 
 
 (751) What is the usual order of preliminary survey ? 
 
 (752) How are measurements to be made ? 
 
 (753) Give a brief sketch illustrating the mode of laying 
 out base lines and subdivisions. 
 
 (754) How are base lines rendered permanent ? 
 
 (755) What important requirement is met by locating 
 street corners by intersecting lines ? 
 
RAILROAD LOCATION 
 
 (ARTS. 1391-1452.) 
 
 (756) What is the first duty of the chief engineer ? 
 
 (757) What are terminals ? 
 
 (758) From what sources does the engineer gain infor- 
 mation of the section of country to be operated in ? 
 
 (759) What is the prime object in building a railroad ? 
 
 (700) What is your idea of the distinction between 
 matters which are financially important and those which 
 are physically important ? 
 
 (7G1) What is the average continuous cut and fill, with 
 proportionate amount of masonry that will equal the cost 
 of the superstructure, i. e., ties, rails and fastenings, and 
 ballast ? 
 
 (702) What are the main sources of traffic, and what 
 measures should be taken to reach them ? 
 
 (763) What knowledge will enable the engineer to prop- 
 erly estimate the comparative cost of different lines ? 
 
 (764) Ordinarily, how many different routes will it be 
 necessary for the engineer to examine, and what are the 
 considerations which narrow the field of operations ? 
 
 (705) Define a reconnaissance, and its relative importance 
 to other departments in the work of location. 
 
 (700) What assistance will the engineer requiie in ma- 
 king the reconnaissance ? How will he conduct the same, 
 and what range of country should he cover ? 
 
 (767) Of what use is the hand level ? 
 
1316 RAILROAD LOCATION. 
 
 (708) What records should be kept ? What do the sizes 
 and rate of current of different streams indicate ? 
 
 (7G9) Give examples of the deceptive appearance of 
 country, and state how the eye tends to exaggerate offsets, 
 angles, and distances. 
 
 (770) In general, how should local reports and estimates 
 of country be regarded ? 
 
 (771) Are conditions often met where but one line is 
 possible ? 
 
 (772) What advantages do valleys possess over ridges or 
 rolling country ? 
 
 (773) What is the organization of a location party ? what 
 the necessary outfit ? 
 
 (774) Under what conditions should the compass be 
 used ? 
 
 (775) How is the starting point usually determined with 
 reference to other fixed lines or boundaries ? 
 
 (77G) Describe the order of conducting the preliminary 
 survey. 
 
 (777) Describe the work of the level and topographical 
 parties. 
 
 (778) What constitutes the office work of the preliminary 
 survey ? 
 
 (779) Define spur lines. 
 
 (780) Define a gradient, and state what considerations 
 modify or determine gradients. 
 
 (781) What conditions limit curvature, and what lati- 
 tude should the engineer be allowed in their use ? 
 
 (782) What are temporary lines, and when and where 
 may they be used to advantage 1 
 
 (783) What is a paper location ? 
 
 (784) Describe how field notes are made up from the 
 paper location. 
 
 (785) What is a paper location profile ? 
 
 (786) What constitutes the location party ? 
 
RAILROAD LOCATION. 1317 
 
 (787) A curve whose intersection angle is 32° 30' is run 
 in, and it is found that its tangent is parallel to the required 
 tangent, but 20 ft. outside of it. How far backward must 
 the P. C. be moved in order that the tangent may take its 
 proper position ? Ans. 48.39 ft. 
 
 (788) If the intersection angle is 41° 20' and the follow- 
 ing tangent is parallel, but falls 13.4 ft. within the required 
 tangent, how far forward must we move the P. C. ? 
 
 Ans. 20.29 ft. 
 
 (789) A compound curve in which the first curve is 6° 
 and the second curve 9°, with an intersection angle of 
 34° 20', terminates in a tangent parallel to but 26.4 ft. with- 
 out a given required tangent; how far backward must the 
 P.* C. C. be moved in order that the tangent may take the 
 prescribed position ? Ans. 128.33 ft. 
 
 (790) A compound curve in which the first curve is 3° 
 and the second curve 7°, with an intersection angle of 36° 
 40', terminates in a tangent parallel to but 32.4 ft. within a 
 given required tangent; how far forward must the P. C. C. 
 be moved in order that the tangent may take the prescribed 
 position? Ans. 98.33ft. 
 
 (791) A compound curve in which the first curve is 4° and 
 the second curve 0°, with an intersection angle of 37° 10'. 
 terminates in a tangent parallel to but 56 ft. without a given 
 required tangent; how far backward must the P. C. C. be 
 moved in order that the tangent may take its required 
 position? Ans. 250.4 ft. 
 
 (792) A compound curve in which the first curve is 8° 
 and the second curve 3°, with an intersection angle of 28° 40', 
 terminates in a tangent parallel to but 25.4 ft. without the 
 required tangent; how far forward must the P. C. C. be 
 moved in order that the tangent may take its proper 
 position ? Ans. 33.33 ft. 
 
 (793) A compound curve in which the first curve is 9" 
 and the second 4°, wkh an intersection angle of 36° 15', ter- 
 minates in a tangent parallel to but 33 ft. within the 
 
1318 RAILROAD LOCATION. 
 
 required tangent ; how far backward must we move the P. C. C. 
 in order that the tangent may take its required position ? 
 
 Ans. 42. 78 ft. 
 
 (794) The P. C. and P. T. of a 7° curve having been 
 established, it is found that obstacles lie in the path of the 
 curve, and it is decided to run a parallel curve 100 feet with- 
 in the 7° curve from which the stations on the required 
 curve may be located ; what will be the length of each chord 
 corresponding to full stations on the required 7° curve ? 
 
 Ans. 87.79 ft. 
 
 (795) Two angles of intersection are 34° 20' and 41° 30; 
 the distance between the points of intersection is 1,011 feet; 
 what is the radius of the easiest reverse curve which will 
 unite the given tangents ? 
 
 Ans. Radius = 1,469.94 ft. = 3° 53.9' curve. 
 
 (796) Two angles of intersection are 20° 14' and 41° 08'; 
 the distance between points of intersection is 816 feet; what 
 is the radius of the easiest reverse curve which will unite the 
 tangent ? Ans. Radius = 1,473.88 ft. = 3° 53.3' curve. 
 
 (797) The angle E B C \n Fig. 17 = 28° 40', the angle 
 FC B=dO° 16', and the line B C = 470 ft. ; required, the 
 
 Fig. 17. 
 
 radius of the curve which will be tangent to the lines A B, 
 B C, and C D. Ans. Radius = 893.6 ft. = 6° 24.7' curve. 
 
 (798) In Fig. 17 let the angle E BC = 32° 50', the angle 
 F C B — 4:1° 20', and the side B C= 516 ft. ; required, the 
 radius of the curve tangent to A B, B C, and C D. 
 
 Ans. Radius = 768.05 ft. = 7° 27.6' curve. 
 
 (799) A preliminary line crosses a wide stream, and a 
 plug is set on line on both sides of the river. The transit is 
 set over one plug, and an angle of 1° is then turned from the 
 
RAILROAD LOCATION. 
 
 1310 
 
 line of survey and a plug set directly opposite to the plug on 
 the other side of the stream. If the distance between these 
 plugs is 7.3 ft., what is the w^idth of the river ? 
 
 Ans. 418.3 ft. 
 
 (800) What opportunity does clearing the right of way 
 afford for bettering the line ? 
 
 (801) How are transit points referenced, and what is the 
 object of referencing them ? 
 
 (802) When are final levels taken ? Of what are they 
 the basis ? 
 
 (803) What is the principal effect of curvature upon 
 passing trains ? What are the usual compensations for 
 curvature ? 
 
 (804) The location notes between Stations 20 and 40 are 
 as follows : 
 
 Stations. 
 
 Intersection 
 Angles. 
 
 Elevation of Grades. 
 
 40 
 
 
 142.50 
 
 36 + 30 P. T. 
 
 • 
 
 137.6271 
 
 31 + 80 P. C. 8° L. 
 
 36° 00' 
 
 132.7806 
 
 28 + 70 P. T. 
 
 
 128.6979 
 
 24 -f 50 P. C. 10° R. 
 
 42° 00' 
 
 124.4265. 
 
 20 
 
 
 118.50 
 
 Assuming that the elevation of grade of Sta. 20 is 118.50 
 ft., and the elevation of grade at Sta. 40 is 142.50 ft., and 
 allowing a compensation of .03 ft. per degree, what are the 
 grades for the tangents and curves, and what are the eleva- 
 tions of grade at the points of curve and tangent on the 
 given line ? Explain the process by which the rates of grade 
 and elevations are determined. 
 
 (805) When are vertical curves employed, and what is 
 their object ? 
 
bered in regular notation ? 
 
 Ans. 
 
 1320 RAILROAD LOCATION. 
 
 (80G) Two grade lines, the first an ascending grade of 
 1 per cent., and the second a descending grade of 0.8 per 
 cent., are to be united by a parabolic vertical curve of a 
 length of GOO ft. What is the value of a\ and if the eleva- 
 tion of the beginning of the curve on the ascending grade is 
 110 ft., what are the elevations of the grades for the re- 
 maining stations of the curve, the starting point of the 
 curve being Sta. 0, and the remaining stations being num- 
 
 a = Q.\5 ft. 
 Grade at Sta. = 110 ft. 
 Grade at Sta. 1 = 110.85 ft. 
 Grade at Sta. 2 = 111.4 ft. 
 Grade at Sta. 3 = 111.65 ft. 
 Grade at Sta. 4 = lll.G ft. 
 Grade at Sta. 5 = 111.25 ft. 
 Grade at Sta. 6 = IIO.G ft. 
 
 (807) Draw a figure showing the grade lines specified in 
 the previous question, and the vertical curve required to 
 unite them. 
 
 (808) What is the usual classification of materials to be 
 handled or used in the work of construction ? 
 
 (809) What are the usual slopes given to earth cuts, rock 
 cuts, and embankments ? 
 
 (810) How is the line divided before construction is 
 commenced, and what are the divisions called ? 
 
 (811) What is the standard width of right of way ? 
 
 (812) In advertising work for contract, what important 
 reservation should the company make ? 
 
RAILROAD CONSTRUCTION. 
 
 (ARTS. 1453-1502.) 
 
 (813) When a line of railroad is in readiness for construc- 
 tion, how is it subdivided ? 
 
 (814) What are the duties of the division engineer ? 
 
 (815) What are the slopes usually given in setting slope 
 stakes for embankment and for excavation ? 
 
 (81G) The height of instrument is 127.4 feet, the eleva- 
 tion of grade is 140 feet, and the rod reading for the right 
 slope is 9.2 feet; what is the fill and the distance of the right 
 slope stake from the center line, the roadway being IG feet 
 in width? ^^^ j" Fill, 21.8 feet. 
 
 I Side distance, 40.7 feet. 
 
 (817) The height of instrument is 96.4 feet, the grade 
 78.0 feet, the rod reading at the center line is 4.7 feet; what 
 is the amount of cutting ? Ans. 13.7 feet. 
 
 (818) With the same height of mstrument and grade as 
 in question 5 and a left rod reading of 8.8 feet, what is the 
 cutting and the side distance, the width of roadway being 
 18 feet ? ^^^ j Cut, 9.G feet. 
 
 ( Side distance, 18.6 feet. 
 
 (819) How should the operation of clearing be con- 
 ducted ? 
 
 (820) Describe the modern mode of grubbing stumps. 
 
 (821) Name the different classes of culverts. 
 
 (822) With a coefficient of 1.8 and a drainage area of 
 400 acres, what should be the area in square feet of a culvert 
 opening ? xVns. 36 square feet. 
 
1322 RAILROAD CONSTRUCTION. 
 
 (823) An embankment is 28 feet in height ; a box culvert 
 with an opening 3 feet wide and 4 feet in height will pass 
 the water. The covering flags are 1 foot thick, and the 
 parapet 1 foot high. (r?) What will be the distance from 
 the center line to the face of the culvert ? (d) What will 
 be the distance from the face of the abutment to the end of 
 the wing walls ? 
 
 . j From center to face of culvert, 44 ft. 4 in. 
 
 ( From face of abutment to end of wing wall, 9 ft. G in. 
 
 (824) What should be the limit of the span of a box cul- 
 vert; and when a greater opening is required to pass the 
 water, how is it obtained ? 
 
 (825) What is the usual foundation for a box culvert, 
 and how is it prepared ? 
 
 (826) What are some of the means employed to obtain a 
 secure foundation in soft or marshy soils ? 
 
 (827) What are tile culverts; under what conditions are 
 they ordinarily employed, and how are they built ? 
 
 (828) How should cattle guards be built ? 
 
 (829) The height of the embankment at an open passage- 
 way is IG feet; what should be the thickness of the base of 
 the wall directly below the center line ? Ans. 6.4 ft. 
 
 (830) Name the different parts of an arch. 
 
 (831) Name the different classes of arches, and describe 
 them. 
 
 (832) The radius of a semicircular arch of cut stone is 
 15 feet; what should be the depth of the keystone ? Give 
 depths by both Trautwine's and Rankine's formulas. 
 
 » j By Trautwine's formula, depth of keystone = 1.57 ft. 
 ( By Rankine's formula, depth of keystone = 1.34 ft. 
 
 (833) The span of a segmental arch is 38 feet ; the rise 
 is 12 ft. ; what is the length of the radius which will touch 
 the soffit of the arch at the springing lines and crown ? 
 
 Ans. 21.04 ft. 
 
 (834) The radius of an arch is 12 ft. and the rise 8 ft. ; 
 
RAILROAD CONSTRUCTION. 1323 
 
 what should be the thickness of the abutments at the spring 
 Hne, providing their height is not more than 1^ times the 
 width of their base ? Ans. 5.2 ft. 
 
 (835) {a) What are the essential ingredients of con- 
 crete ? {d) What are the usual proportions of the in- 
 gredients ? (c) How should they be mixed ? 
 
 (836) What is the object in making the foundation area 
 greater than that required for the superstructure .'' 
 
 (837) What is the advantage of ramming concrete ? 
 
 (838) What are suitable proportions of sand and cement 
 for mortar to be used in arch culvert masonry, and how 
 should the ingredients be mixed ? 
 
 (839) What is the minimum tensile strength per square 
 inch of neat cement of 24 hours' age allowable in arch cul- 
 vert work ? 
 
 (840) What is the object in pointing the joints of mason- 
 ry? Describe the process. 
 
 (841) What are arch centers, their object, and how 
 built ? 
 
 (842) What are striking or lowering wedges, and what 
 purpose do they serve ? 
 
 (843) In laying arch stones, how should the beds be 
 arranged ? 
 
 (844) When should the backing of an arch be started ? 
 
 (845) At what stage in the building of an arch is the 
 pressure liable to lift the crown ? When is the pressure 
 liable to lift the haunches ? 
 
 (84:0) At what angle to the faces of an arch culvert are 
 wing walls usually built ? 
 
 (847) What, is a retaining wall ? 
 
 (848) A retaining wall of mortar rubble 10 feet in height 
 is required to sustain an embankment of earth level with 
 its top; what should be the thickness of its base, the front 
 being battered 1 inch to the foot and the back vertical ? 
 
 Ans. 4 ft. 
 
1324 RAILROAD CONSTRUCTION. 
 
 (849) How does inclining the base of a retaining wall 
 backwards affect its stability ? 
 
 (850) What effect is produced by battering the back of 
 the wall ? 
 
 (851) In latitudes where deep freezing occurs, what 
 measures should be taken to withstand its effects ? 
 
 (852) What produces the effect of bulging in retaining 
 walls ? 
 
 (853) Illustrate by figure the method of offsetting the 
 backs of retaining walls so as to increase their base without 
 increasing their volume. 
 
 (854) What are surcharged walls ? 
 
 (855) Explain by figure the angle, the slope, and the 
 prism of maximum pressure. 
 
 (856) In determining the dimensions of a retaining wall, 
 what is the unit length of section of wall and backing used ? 
 
 Ans. 1 ft. 
 
 (857) When the backing is level with the top of the 
 wall, at what point of the back of the wall is the center of 
 pressure ? 
 
 (858) Give the formula for perpendicular pressure, with 
 explanatory figure. 
 
 (859) What are the forces which give to a retaining wall 
 its stability ? 
 
 (800) What is meant by the angle of wall friction ? 
 
 (8G1) The height o d (see Fig. 18) of the retaining wall 
 a b d c \s\^ ft. The thickness at the base ^ </ is 8 ft. ; the 
 thickness at the top rt- ^ is 2.5 ft. ; the front is battered 1 inch 
 to the foot, and the base b f oi the triangle b d fis 12.73 feet. 
 Taking the weight of the backing at 120 pounds per cubic 
 foot and the weight of the wall at 154 pounds per cubic foot, 
 determine graphically to a scale of 4,000 lb. = 1 in. the 
 resultant of the forces tending to overturn the wall about 
 its toe f as a fulcrum. 
 
 (862) What does earth work embrace ? 
 
RAILROAD CONSTRUCTION 
 
 1325 
 
 Fig. 18. 
 
 (863) Describe the different sections formed by the 
 roadway. 
 
 (864) What character of work is best performed by a 
 road machine ? 
 
 (865) What is meant by the term " lead "? 
 
 (866) With a lead of 400 feet and wages at $1.15 per day, 
 what would be the cost per cubic yard to the contractor for 
 delivering earth at the dump, the gang niimbering 25 men, 
 with foreman at $2.00 per day, water carrier at $0.90 per 
 day, and allowing 1 pick to 5 wheelbarrows and ^ cent per 
 yard for wear of tools and barrows ? Ans. 21.24 cents. 
 
 (867) With a lead of 700 feet and wages at $1.20 per day, 
 what will be the cost per cubic yard to the contractor to de- 
 liver light sandy soil upon the dump, carts with driver cost- 
 ing $1.40 per day; foreman in charge of 12 carts, $2.25 per 
 day; water carriers, $1.00 per day; dumping and spreading, 
 1 cent per cubic yard ; number of minutes actually employed 
 by shovelers, 420 per day ; rate of travel for carts, 100 feet 
 of lead per minute; time consumed in loading and turning 
 and dumping, 4 minutes, allowing 2 cents per cubic yard 
 
1326 RAILROAD CONSTRUCTION. 
 
 for loosening soil and ^ cent per cubic yard for use and wear 
 of tools ? Ans. 1G.97 cents. 
 
 (868) Name the different methods of hand drilling. 
 
 (869) What special advantages have jumper drills over 
 churn drills ? 
 
 (870) What are percussion drills ? 
 
 (871) In the percussion drill, how is the rotation of the 
 drill effected ? 
 
 (872) What are the advantages of compressed air over 
 steam for tunnel work ? 
 
RAILROAD CONSTRUCTION. 
 
 (ARTS. 1503-1592.) 
 
 (873) At what depth of cutting does it become expedient 
 to drive a tunnel ? 
 
 (874) What is the most favorable time in the day for 
 running tunnel lines, and what conditions of the atmos- 
 phere are necessary for accurate results ? 
 
 (875) What is the object of running the line by fore- 
 sights ? 
 
 (876) What are the usual methods employed in measuring 
 the surface line ? 
 
 (877) Assuming 60" F. as normal temperature, what is 
 the correct length of a line which measures 89.621 feet, the 
 temperature being 94° ? Ans. 89.641 ft. 
 
 (878) The distance between two points on a tunnel line 
 as measured on the slope is 89.72 feet; the difference of 
 elevation between the extremities is 11.44 feet; what is the 
 horizontal distance between the extremities ? 
 
 Ans. 88.986 ft. 
 
 (879) What are standard dimensions for a single track 
 tunnel section ? what for a double track ? 
 
 (880) In tunnel driving, how is the section of the tunnel 
 divided ? * 
 
 (881) Show by figure the arrangement of drill holes in 
 the heading and bench. 
 
 (882) What is the usual order of firing the holes ? 
 
 (883) What is the first consideration in determining tun- 
 nel grades ? What rate of grade will insure complete 
 drainage ? 
 
1328 RAILROAD CONSTRUCTION. 
 
 (884) What is the usual arrangement of tunnel tracks ? 
 
 (885) The elevation of the grade of a station in a tunnel 
 is 162.0 feet; the height of instrument is 179.3 feet; the 
 height of the tunnel section is 24 feet; what should the rod 
 read when the roof is at grade ? Ans. 6.7 ft. 
 
 (886) In tunnel work, what special advantage is obtained 
 by sinking shafts ? 
 
 (887) Describe the usual arrangement of tunnel tracks 
 and scaffolding for loading excavated material. 
 
 (888) Briefly describe the process of tunneling through 
 soft ground. 
 
 (889) How is the center line of the tunnel run and 
 maintained during construction ? . 
 
 (890) Describe the process of plumbing a shaft. 
 
 (891) How much pure air per minute does a man require 
 in order that he may do effective work ? 
 
 (892) An 18-inch air pipe conveys air from a tunnel 
 heading at a velocity of 13 feet per second ; how many laborers 
 will it provide with pure air, allowing 100 cubic feet per man 
 per minute ? Ans. 14 laborers. 
 
 (893) What is an average day's work for a machine drill 
 in lineal feet of hole drilled ? 
 
 (894) What are surface ditches ? 
 
 (895) What are cribs, and how are they used in protection 
 work ? 
 
 (896) Where is stone paving usually employed in works 
 of protection ? 
 
 (897) A culvert crosses a railroad line at an angle of 75°; 
 the opening is three feet in height; the covering flags and 
 the parapet each 1 foot in height, and the embankment 21 
 feet in height. What should be the distance from the center 
 line to the face of the culvert ? Ans. 36.06 ft. 
 
 (898) What are borrow pits ? 
 
 (899) How should they be staked out ? 
 
RAILROAD CONSTRUCTION. 
 
 1329 
 
 (900) How should they be mapped and their contents 
 calculated ? 
 
 (901) What are grade stakes ? 
 
 (902) The grade at a station is 118.7 ft. ; the height of 
 instrument is 125.5 ft.; what should the rod read at the 
 station, for the roadway to be at grade ? Ans. G.8 ft. 
 
 (903) What does the term overhaul signify ? 
 
 (904) What are the two important factors in the location 
 of a bridge ? 
 
 (905) What is the meaning of the term skew as applied 
 to bridges ? 
 
 (906) Describe a method of making a direct measurement 
 of a bridge span ? 
 
 (907) Let A B (see Fig. 19) be the center line of the pro- 
 posed bridge, and B C the base line, the length of 
 which is 421.532 ft. The angle A is 46° 55'; the angle C 
 is 43° 22' ; required, the 
 length of A B. 
 
 Ans. 396.31 ft. 
 
 (908) What are some 
 of the considerations 
 which determine the 
 number and location of 
 the piers of a bridge ? 
 
 (909) When the river 
 bed is of rock, or firm 
 sand, or clay, how are 
 pier foundations pre- 
 pared ? 
 
 (910) What are coffer- 
 dams ? Fio- «• 
 
 (911) A side of a cofferdam is 40 feet in length and 11 
 feet in height; the water is 10 feet in depth; {a) what is 
 the total water pressure against the side of the dam ? (b) 
 
the dam? ^^^ ( (a) 17.875 ft. -lb. 
 
 1330 RAILROAD CONSTRUCTION. 
 
 What is the moment of the water pressure about the inner 
 tee of the dam ? j^^^ j {a) 125,000 lb. 
 
 * ( (^) 10,471 ft. -lb. 
 
 (912) If the filling of the dam is 5 feet in thickness, 
 11 feet in height, and weighs 130 lb. per cu. ft., (a) what is 
 the moment of resistance of which the filling alone opposes 
 to the water pressure ? {d) What is the factor of safety of 
 
 ■ ( (^) 1.71. 
 
 (913) Under what conditions would you construct a pile 
 foundation ? 
 
 (914) How would you protect the foundation from the 
 scour of the current ? 
 
 (915) What stone is best suited to bridge foundations .'' 
 (91G) In building bridge piers, what are the different 
 
 materials used for backing ? 
 
 (917) Under what conditions are pneumatic foundations 
 employed ? 
 
 (918) What are tfsi holes as employed in foundation 
 work, and how are they ordinarily made ? 
 
 (919) Describe the construction and use of the sand 
 pump. 
 
 (920) How does the depth of the foundation affect the 
 size of the caisson ? 
 
 (921) What is the object in battering the sides of a 
 caisson ? 
 
 (922) How is entrance to the caisson chamber effected ? 
 
 (923) E.xplain the working of the air locks. 
 
 (924) How is the air pressure within the caisson utilized 
 in removing the material excavated in sinking the caisson } 
 
 (925) How is the sinking of the caisson regulated ? 
 
 (926) Describe the process of sealing the caisson. 
 
 (927) What is the air pressure in the caisson at a depth 
 of 70 feet below the water surface .'' 
 
 Ans. 45*38 lb. per sq. ia 
 
RAILROAD CONSTRUCTION. 1331 
 
 (928) Give the Engineering News' formula for pile 
 driving. 
 
 (929) What are the various methods employed in pile 
 driving ? 
 
 (930) A hammer weighing 3,500 pounds falls free from 
 a height of 30 feet upon the head of a pile ; what is the force 
 of the blow ? Ans. 105,000 ft. -lb. 
 
 (931) When driving a pile, what is the effect of an 
 interval of rest between blows ? 
 
 (932) What effect have broomed pile heads upon the 
 striking force of the hammer ? 
 
 (933) What effect results from driving piles with hammer 
 rope slackened on the drum ? 
 
 (934) Describe pile shoes and hoops, and state their 
 object. 
 
 (935) What are some of the effects of overdriving piles ? 
 What is the safe limit in spacing bearing piles ? What are 
 the effects of overcrowding ? 
 
 (930) A hammer weighing 3,000 pounds falls from a 
 height of 22 feet; the average penetration of the last three 
 blows is \ inch ; what is the safe load in tons which the pile 
 will support ? Ans. 44 tons. 
 
 (937) A trestle bent contains three piles. In driving 
 them a hammer weighing 3,300 pounds, falling from a 
 height of 35 feet, produces the following last penetrations, 
 viz., first pile, J inch; second pile, |inch; third pile, | inch; 
 required, the total safe load of the bent in tons. 
 
 Ans. 191.77 tons. 
 
 (938) Into what two general classes are pile-driving 
 machines divided ? 
 
 (939) What are the essential parts of a pile-driving 
 machine ? 
 
 (940) What are sheet piles ? 
 
 (941) What is the prismoidal formula, and what applica- 
 tion is made of it in estimating earth work ? 
 
1332 RAILROAD CONSTRUCTION. 
 
 (942) Describe the quantity book. 
 
 (943) What are monthly estimates; when are they made, 
 and how do they reach the chief engineer ? 
 
 (944) What are temporary allowances ? 
 
 (945) What percentage of the estimate is usually reserved 
 by the company, and what is the object of such a reserva- 
 tion ? 
 
 (946) What is the final estimate ? 
 
TRACK WORK, 
 
 (ARTS. 1593-1727.) 
 
 (947) What constitutes a gooa tracK ? 
 
 (948) Why is a hewn tie superior to a sawed tie ? 
 
 (949) Name the months most favorable for cutting tie 
 timber. 
 
 (950) (a) What are proper dimensions for standard 
 gauge cross-ties ? (d) Where should they be piled for in- 
 spection, and what are the usual marks employed by a tie 
 inspector ? 
 
 (951) (a) At what interval should track centers be 
 placed ? (d) At what intervals should stakes for bedding 
 ties be placed ? 
 
 (952) What is an average day's work in track laying with 
 a machine ? 
 
 (953) (a) How are ties lined ? (d) how bedded ? 
 
 (954) Define suspended and supported joints. 
 
 (955) Describe the proper method of transferring rails 
 from car to car, and of delivering them from the car to the 
 grade. 
 
 (956) How may kinked rails be straightened ? 
 
 (957) A curve contains 42°; how many 29^-ft. rails are 
 required to keep the joints in proper position ? 
 
 Ans. 7 rails. 
 
 (958) At a temperature of 85°, an iron bar measures 
 30.016 feet; assuming normal temperature at 60°, what is 
 the normal length of the bar ? Ans. 30.011 ft. 
 
 (959) What are expansion shims, and their objects ? 
 
1334 TRACK WORK. 
 
 (9G0) What is the proper mode of driving spikes, and 
 how should they be arranged .in the tie ? 
 
 (9G1) What is the proper mode of gauging track ? 
 
 (962) Describe the process of lining track. 
 
 (963) After a new track is laid, what are the steps taken 
 to put it into surface ? 
 
 (9G4) What is subgrade ? 
 
 (965) State some of the methods for effecting the drain- 
 age of cuttings. 
 
 (966) Give sketch showing section of track in earth 
 ballast and in rock ballast. 
 
 (967) What is the effect of straining track bolts ? 
 
 (968) Describe the process of putting new ties into a 
 track. 
 
 (969) How is old track prepared for ballasting with stone 
 or gravel ? 
 
 (970) What is the proper method to be employed in 
 raising track ? 
 
 (971) What is the most effective form of fence for fen- 
 cing a railroad ? 
 
 (972) What height of fence is prescribed by law in most 
 of the States ? 
 
 (973) What are shims ? 
 
 (974) What effect has frost upon pile bridges ? 
 
 (975) How are snow drifts prepared for the snow plow ? 
 
 (976) Where are snow fences required, and how located ? 
 
 (977) An 8° curve is 425 feet in length, the gauge of 
 track is 4 feet 9 inches, the width of the rail head, 2 inches; 
 what is the excess of length of the outer rail over the inner 
 rail ? Ans. 2.91 ft. 
 
 (978) What is the middle ordinate of a 30-foot rail for a 
 6° curve ? Ans. 1^ in. 
 
 (979) The middle ordinate of a 50-foot chord is 3^ inches; 
 what is the degree of the curve ? Ans. 5° 36'. 
 
TRACK WORK. VVAo 
 
 (980) Why is it necessary to widen the gauge on sharp 
 curves ? 
 
 (981) What is the proper method of lining curves ? 
 
 (982) What is the formula for curve elevation ? 
 
 (983) A curve is 10°, and the velocity of train is 35 miles 
 
 per hour; by the formulas c = 1.587 V and ;// = -5-77, what 
 
 should be the elevation of the outer rail of the curve •? 
 
 Ans. 8 in., nearly. 
 
 (984) If the elfevation of the outer rail of a curve is 
 4 inches, what should be the length of the elevated approach ' 
 
 Ans. 240 ft. 
 
 (985) What is the object of coning the treads of car 
 wheels ? 
 
 (980) What is a turnout ? 
 
 (987) What do you understand by the number of a frog ? 
 
 (988) Name the two classes of frogs, and describe them. 
 
 (989) What are crossing frogs ? 
 
 (990) What is a replacing frog, and how is it used ? 
 
 (991) Name the two principal types of switches. 
 
 (992) Describe the stub switch. 
 
 (993) Describe the split switch. 
 
 (994) {a) What is a facing switch ? {d) a trailing switch ? 
 
 (995) What is a safety switch ? 
 (990) What is a three-throw switch ? 
 
 (997) What are derailing switches ? 
 
 (998) What are automatic turnouts ? 
 
 (999) What is a Y track ? 
 
 (1000) The radius of the turnout curve from a straight 
 track is 002.8 feet, and the gauge is 4 feet 8.J^ inches; what 
 is the frog number ? Ans. No. 8 frog. 
 
 (1001) In a turnout from a straight track, the number 
 of the frog is 0, the gauge of the track is 4 feet 8^ inches; 
 what is the radius ? Ans. 339 ft. = 16° 54' curve. 
 
1336 TRACK WORK. 
 
 (1003) The degree of the turnout curve from the straight 
 track is 18°, the gauge is 4 feet 9 inches; what is the frog 
 distance and frog angle ? 
 
 . ( Frog distance = 55.1 ft. 
 I Frog angle = 9° 55'. 
 
 (1003) The main track is a 0° curve, and to reach a cer- 
 tain warehouse it is necessary to use a 10° 30' curve in the 
 opposite direction from that of the main track; what is the 
 required frog distance and frog angle, the gauge at the track 
 being widened to 4 feet 9 inches ? 
 
 . j Frog distance = 57.5 ft. 
 - i Frog angle = 9° '29f . 
 
 (1004) The main track is a 4° curve to the right, and to 
 reach a certain point it is necessary to put in a 12° turnout 
 curve to the right; how far from the P. C. of the turnout 
 curve shall we place the head, block, if we allow 5 inches be- 
 tween the gauge lines, the gauge being widened to 4 feet 
 9 inches ? ' Ans. 24.5 ft. 
 
 (1005) If the spread of the heel of a No. 9 frog is 8^ inches, 
 what is the distance from the heel to the theoretical point 
 of frog ? Ans. G ft. 4| in. 
 
 (1006) At what distance from the gauge line should a 
 guard rail be placed, when the track is laid to a close gauge ? 
 
 Ans. If in. 
 
 (1007) The distance from the head block of a switch to 
 the last long tie behind the frog is 60 feet ; the ties being 
 15 inches apart, how many switch ties are required for the 
 switch ? Ans. 48. 
 
 (1008) The length of the tie next the head block is 8 feet 
 6 inches, the length of the last long tie behind the frog is 
 15 feet 3 inches, the number of switch ties is 48; what is the 
 amount to be added to the length of each tie to give the 
 length of the next ? Ans. 1\^ in. 
 
 (1009) How do you obtain the length of switch timbers 
 for a three-throw switch ? 
 
 (1010) A three-throw switch is formed by two turnout 
 
TRACK WORK. 1337 
 
 curves at 10° each ; what is the angle of the crotch frog, the 
 gauge being 4 feet 8^ inches ? Ans. 10' 22.8'. 
 
 (1011) What are cross-over tracks ? 
 
 (1012) What is the proper method of lining detached 
 track ? 
 
 (1013) When cutting steel rails, what precautions should 
 be taken ? 
 
 (1014) At what distance from the point of danger should 
 danger signals be placed ? 
 
 (1015) At what distance from stations should whistling 
 posts be located ? 
 
 (1016) When repairing track, what precautions should 
 be taken to protect trains ? 
 
RAILROAD STRUCTURES. 
 
 (ARTS. 1728-1824.) 
 
 (1017) What is the average Hfe of a wooden trestle ? 
 
 (1018) Why are mathematical formulas less reliable for 
 designing structures of wood than structures of metal ? 
 
 (1019) What should be the limit in height for a pile 
 trestle ? 
 
 (1020) What advantage is derived from piles driven at a 
 batter ? 
 
 (1021) Under what conditions may a 3-pile bent be 
 employed ? 
 
 (1022) What conditions require the splicing of piles ? 
 
 (1023) Before ordering the material for a pile bridge, 
 what measures should be taken to determine the necessary 
 length of piles required ? 
 
 ■ (1024) Name the different methods of fastening caps to 
 piles. 
 
 (1025) (a) What is the standard size of mortise and 
 tenon for post, cap, and sill connections ? (/;) What are 
 treenails ? 
 
 (1026) What are the special merits of s^/if caps f 
 
 (1027) What advantages, besides stability, result from 
 proper foundations for trestles ? 
 
 (1028) Name the several kinds of foundations employed 
 in trestle building. 
 
 (1029) Under what conditions would you employ a 
 grillage foundation ? 
 
 (1030) How are crib foundations constructed, and to 
 what situations are they best suited ? 
 
1340 RAILROAD STRUCTURES. 
 
 (1031) How are foundations of broken stone prepared ? 
 
 (1032) What are drip holes, and what purpose do they 
 serve ? 
 
 (1033) What are corbels, and their object ? 
 
 (1C34) What are separators, and their object ? 
 
 (1035) What are packing-blocks, and their object ? 
 
 (103G) What two methods are commonly adopted to 
 fasten stringers to caps ? 
 
 (1037) What are spreaders ? 
 
 (1038) What are the safe standard dimensions tor 
 stringers for standard trestles ? 
 
 (1039) What are jack-stringers, and their object ? 
 
 j(1040) (n) At what distance apart should trestle ties be 
 spaced ? (d) What advantage results from placing them 
 close together ? 
 
 (1041) What advantage results from notching down the 
 ties over the stringers ? 
 
 (1042) What are guard-rails, their object, and how are 
 they fastened to the ties ? 
 
 (1043) How are guard-rails spliced ? 
 
 (1044) What modification should be made in the form 
 of the guard rail at the connection of the trestle with the 
 embankment ? 
 
 (1045) What are sway-braces, and their object ? 
 
 (1046) How is the elevation of the outer rail effected on 
 curved trestles ? 
 
 (1047) Which form of drift-bolts has the greater holding 
 power, round ones or square ones ? 
 
 (1048) In what two ways are trestles commonly connected 
 with embankments ? 
 
 (1049) ^Name some devices for protecting trestles against 
 fire. 
 
RAILROAD STRUCTURES. 1341 
 
 (1050) Describe the usual method of erecting trestles. 
 
 (1051) What is the principal object of numbering 
 bridges ? 
 
 (1052) In building pile trestles, what is the object of 
 notching the caps over the piles ? 
 
 (1053) A spruce beam is 10 inches broad, 12 inches deep, 
 and 18 feet long; what is its center breaking load ? 
 
 Ans. 36,000 lb, 
 
 (1054) When beams are inclined, what constitutes the 
 span ? 
 
 (1055) A square horizontal beam of yellow pine is 20 feet 
 in length between supports; what should be its dimensions 
 to break under a quiescent center load of 50,000 pounds ? 
 
 Ans. 12f in. square, nearly. 
 
 (1056) A beam having a span of 16 feet must safely bear 
 a center load of 16,000 pounds; what should be the side of a 
 square beam of yellow pine to carry this center load with a 
 factor of safety of 5 ? Ans. 13:^^ in. 
 
 (1057) A horizontal rectangular beam of spruce is 
 12 inches in depth and 14 feet between supports ; what should 
 be its breadth to break under a quiescent center load of 
 40,000 pounds ? Ans. 8f in. 
 
 (1058) A horizontal rectangular beam of yellow pine is 
 10 inches broad ; the distance between supports is 16 feet; 
 what should be the depth of the beam to break under a 
 quiescent center load of 24,000 pounds ? Ans. 8f in. 
 
 (1059) A rectangular pillar of yellow pine is 12 in. X 12 in. 
 in section, and 12 feet high; what is its safe load with a 
 factor of safety of 5 ? Ans. 91,296 lb. 
 
 (1060) A beam of long-leaf yellow pine is subjected to a 
 shearing stress of 30,000 pounds across the grain; how 
 many square inches of timber are required to resist this 
 stress ? Ans. 60 sq. in. 
 
 (1061) A beam of white oak is subjected to a shearing 
 stress across the grain of 40,000 pounds; how many square 
 inches of timber are required to sustain it ? Ans. 40 sq. in. 
 
1342 RAILROAD STRUCTURES. 
 
 (10G2) What should be the side of a square horizontal 
 beam of spruce which must support, with a factor of safety 
 of 4, a uniformly distributed transverse load of 36,000 pounds, 
 and a pull of 20,000 pounds, the distance between the 
 supports being 12 feet ? Ans. 12. G in. 
 
 (1063) What is a king-rod truss ? 
 
 (1064) A bridge of 20 feet span, and carrying an equiva- 
 lent live and dead load of 6,000 pounds per lineal foot, is 
 carried by king-rod trusses; what is (a) the load upon each 
 king-rod, and (d) what should be the diameter of each, using 
 a factor of safety of 6 ? Ans. {/?) 2f '. 
 
 (1065) If the truss described in the preceding example 
 carries a needle-beam supporting the floor-beams, what share 
 of the total load will the needle-beam support ? 
 
 (1066) What advantage is gained by trussing the 
 needle-beam ? 
 
 (1067) What is a queen-rod truss? 
 
 (1068) A load of 20,000 pounds travels from both ends 
 of the straining bea.m of a queen-rod truss towards the center; 
 Avhat is the total stress in the beam ? 
 
 (1069) A queen truss is 33 feet in length between sup- 
 ports. The combined live and dead load is equivalent to 
 6,000 pounds per lineal foot of bridge. The queen-rods 
 divide the bridge into three equal parts; what is the stress 
 upon each rod ? Ans. 33,000 lb. 
 
 (1070) What are water stations ? 
 
 (1071) What is their ordinary capacity ? 
 
 (1072) What precautions should be taken against drouth 
 or impurities in water due to floods ? 
 
 (1073) What advantage is gained from an elevated water 
 supply ? 
 
 (1074) What is the usual capacity of locomotive tender 
 tanks ? 
 
 (1075) What advantage have the individual stone pedi- 
 ments for posts over woojden sills carried by continuous 
 walls ? 
 
RAILROAD STRUCTURES. 1343 
 
 (1076) What is a water column ? 
 
 (1077) What advantage does the water column offer in 
 its adaptation for yard supply ? 
 
 (1078) What are coaling stations ? 
 
 (1079) What application is made of the link belt in 
 modern coaling stations ? 
 
 (1080) What is a turntable ? 
 
 (1081) What is the proper location for a tool house, and 
 what are its essential requirements ? 
 
 (1082) What are the essential requirements of a section 
 house ? 
 
INDEX, 
 
 PAGE 
 
 982 
 
 railroad 
 
 1066 
 626 
 658 
 
 867 
 933 
 996 
 
 lOOI 
 
 934 
 960 
 611 
 
 Abutments of bridge 
 
 " " stone arches 
 
 Account, Tie 
 Adjustments of transit 
 " Y level 
 Advertising for bids on 
 
 construction . 
 Air compressor . 
 " locks 
 
 " pressure in caissons 
 " receiver 
 Alinement of tunnels 
 Alioth .... 
 Aneroid barometer . 
 
 " " To determine 
 
 elevations with 689 
 
 Angle, Complement of . . . 602 
 
 " Exterior, of triangle 
 
 " line 
 
 " Measure of 
 
 " of frog . 
 
 '• " intersection 
 
 " Slope 
 
 '' Supplement of 
 
 " To lay off, by chords 
 
 " " " " '• its bearing 
 
 " " " " " " tangents . 
 
 " " " " " latitude and 
 
 departure 723, 753 
 
 . 605 
 
 631, 762 
 
 . 604 
 
 . 1104 
 
 • 639 
 . 677 
 . 602 
 
 • 744 
 
 • 747 
 751 
 
 Angles, Alternate exterior 
 " " interior 
 " Checking of, by needle 
 " Deflection 
 " Exterior 
 " horizontal. Measurement of 631 
 " Interior . . . .601 
 " Measurement of, with com- 
 pass 
 
 " Opposite exterior and in- 
 terior 
 
 '■' " interior, of tri- 
 
 angle . . 605 
 •• Platting . . . .741 
 " Vertical . , . .638 
 
 602 
 601 
 
 633 
 642 
 601 
 
 610 
 
 602 
 
 Angular point .... 
 
 Arch stones .... 
 
 Arched culverts 
 
 Arches, Stone .... 
 
 " Elliptical or three centered 
 
 " Segmental . 
 
 " Semicircular 
 
 Area of a surface 
 
 Areas determined by dividing plat 
 
 into trapezoids 
 
 " determined by dividing plat 
 
 into triangles 
 " determined by double longi 
 
 tudes .... 
 " of similar figures . 
 
 B. 
 
 PAGE 
 642 
 
 886 
 887 
 887 
 887 
 7»4 
 
 716 
 
 727 
 603 
 
 PAGE 
 
 Backing of bridge masonry . . 991 
 " " retaining wall . " . 899 
 
 Backsights 610, 630 
 
 Balancing a survey .... 722 
 
 Ballast 1052, 1068 
 
 " Combination . . . io68 
 
 " required for mile of track . 1069 
 
 Bank bent 1208 
 
 " sills 1062 
 
 Bar adjustment of Y levei . . 660 
 Barometer, Aneroid ... . . 688 
 " " Klevations de- 
 
 termined by 689 
 Barometric leveling . . . 656, 688 
 Base line employed in survey of 
 
 town sites . . . 736 
 " " of townships . . . 696 
 
 Batter posts 1183 
 
 Beam compass 776 
 
 " subjected to both transverse 
 
 and longitudinal strains . 1255 
 
 Beams, Horizontal . . 1247, 1250, 1255 
 
 " Inclined .... 1250 
 
 Bearing piles 1006 
 
 "■ trees. Location and mark- 
 ing of .... 707 
 Bearings, Deduced .... 634 
 
Vlll 
 
 INDEX. 
 
 PAGE 
 . €09 
 612 
 747 
 666 
 824 
 
 Bearings, How to take . 
 
 " Magnetic, how corrected 
 " Platting angles by . 
 
 Bench marks 
 
 " " of railroad survey 
 
 *' of tunnel .... 946, 948 
 
 Bender, Rail 1040 
 
 Bents, Erection of . . . .1211 
 
 '• Framed 1177 
 
 " for trestles, Location of . 121 1 
 
 Berme 974 
 
 Bills of material. Proper forms of . 1224 
 Boat spikes .... 1198, 1200 
 
 Bolts 1199, 1203 
 
 " Grip of 1203 
 
 " Number of, for mile of track 1161 
 " Table of weights and stre'ngths 
 
 of ..... . 1261 
 
 Bond, Contractor's . 
 
 . 868 
 
 Borrow pits 
 
 • 861,974 
 
 Boundaries, New 
 
 . 712 
 
 Bracing of trestles . 
 
 • "95 
 
 " " " Lateral 
 
 . T196 
 
 " " " Longitudinal . 1196 
 
 " " " Sway 
 
 • "95 
 
 Breaking the chain . 
 
 . 616 
 
 Bridge approaches, Line and 
 
 sur- 
 
 face of 
 
 . 1062 
 
 " foundations . 
 
 . 982 
 
 " " Caisson 
 
 . 992 
 
 Pile . 
 
 . 987 
 
 " loads 
 
 • 1257 
 
 " masonry, Backing of 
 
 • 991 
 
 " " Coping of 
 
 • 992 
 
 " " Stone suitable for 991 
 
 " Measurement of span 
 
 of . 979 
 
 " numbers 
 
 . 1229 
 
 " timber . 
 
 • 1247 
 
 Bridges, Abutments of . 
 
 . 982 
 
 " Forces operating in 
 
 • 1247 
 
 " Heaved 
 
 . 1081 
 
 " Location of 
 
 . 978 
 
 " Wooden truss . 
 
 . 1246 
 
 Bubble tube of Y level . 
 
 . 658 
 
 Buildings .... 
 
 . 1390 
 
 Bulging of retaining walls 
 
 . 901 
 
 C. PAGE 
 
 Caisson, Air locks of . . . 996 
 
 " " pressure in . . . loot 
 
 " Dimensions of . . . 995 
 " foundations for bridges . 992 
 " Plan of .... 997 
 
 "■ Sealing the . . . looi 
 
 " Sinking the . . . 1000 
 
 Camp outfit for reconnaisance party 833 
 
 PAGE 
 
 Caps, Pile 1175 
 
 Car, Hand . . . . . 1149, 1153 
 Cart work. Cost of . . . . 916 
 
 Cattle guards 883 
 
 Cement, Qualities of . . . 890 
 
 Center cuts and fills .... 856 
 Center line of road, Checking of . 976 
 Centers for arches .... 893 
 " " for tunnel . . . 959 
 
 " Track 1032 
 
 Chain, Breaking the . . .616 
 
 " Engineer's .... 613 
 " Errors in reading . . 614 
 
 Chaining 614 
 
 Check levels 666 
 
 Checking angles by magnetic needle 633 
 " the center line . . . 976 
 
 Chisels 1151 
 
 Chord deflection .... 649 
 Chords, Platting angles by . .744 
 
 Churn drills 928 
 
 Circle, Geometry of . . . . 640 
 Circles of different diameters, how 
 
 compared 604 
 
 Claw bar 1047 
 
 Clearing ground for erection . . 1213 
 " right of way . . . 860 
 " " " Cost of . . 876 
 
 Clinometer 677 
 
 Clips of level 658 
 
 Coaling stations .... 1281 
 
 Cofferdams, Construction of . . 983 
 Collimation, Line of ... 623 
 
 Colored topography .... 806 
 Columns (see Pillars) . . . 1253 
 
 Compass 605 
 
 " Beam 776 
 
 " Defects and inaccuracies 
 
 of 608 
 
 " in railroad surveys . . 614 
 " Lettering of . . . 607 
 
 " levels 608 
 
 " party. Method of work of 616 
 " " Organization of . 615 
 
 " Sights of ... . 606 
 
 " tripod 608 
 
 " Use of in preliminary rail- 
 road surveys . . . 822 
 Compensation for curvature . . 846 
 Complement of an angle . . . 602 
 Compound curve .... 640 
 Compressed air plant for tunnels . 945 
 Compressor, Air .... 933 
 Concrete for foundations, Composi- 
 tion of 890 
 
 Contents of field, Calculation of . 724 
 
INDEX. 
 
 IX 
 
 
 
 PAGE 
 
 Contour lines .... 
 
 673 
 
 " piap 
 
 673. 778, 781 
 
 Contraction of rails . 
 
 
 1043 
 
 Contractor, Duties of 
 
 866, 1219 
 
 , I220 
 
 Contractor's bond 
 
 
 868 
 
 Coping of bridge pier 
 
 
 992 
 
 Corbels 
 
 
 1 186 
 
 Comers (of land survey) 
 
 
 705 
 
 " Closing 
 
 
 709 
 
 " Double land survey . 
 
 708 
 
 " Lost and obliterated . 
 
 7'3 
 
 " Standard . . . . 
 
 709 
 
 Correction lines . . .~ . 
 
 696 
 
 Cost, Comparative, of different rail- 
 
 
 road lines 
 
 815 
 
 Counter posts of trestle bent . 
 
 1196 
 
 Course (of a line) . . . ' . 
 
 609 
 
 Creosoted trestles . . . . 
 
 1216 
 
 Crib foundations for trestle 
 
 1180 
 
 " work, Construction of 
 
 967 
 
 Cribbing, Protection by , 
 
 86s 
 
 Cross-hairs of telescope . 
 
 622 
 
 Crossover tracks. Location of 
 
 "43 
 
 Cross-section notes. Form of . 
 
 874 
 
 Cross-sectioning . . . . 
 
 870 
 
 Cross-sections, Calculation of 
 
 1017 
 
 Cross-ties 969, 
 
 1029 
 
 Crotch frog. Location of . . 1120, 
 
 1142 
 
 Crushing strength .... 
 
 1254 
 
 Culvert, Masonry .... 
 
 864 
 
 Culverts, Arched .... 
 
 885 
 
 " " Foundations for . 
 
 889 
 
 " Box 
 
 878 
 
 " Classification of 
 
 878 
 
 " Heaved . . . . 
 
 1081 
 
 " how laid out . . 
 
 970 
 
 " Open water 
 
 883 
 
 Tile for . . . . 
 
 881 
 
 Curvature, Compensation for . 
 
 846 
 
 " Degree of . . . 
 
 642 
 
 " of railroad 
 
 828 
 
 Curve approaches between reverse 
 
 
 curves 
 
 1098 
 
 " Compound .... 
 
 640 
 
 " Degree of .... 
 
 643 
 
 " Difference in length of inner 
 
 
 and outer rails of 
 
 1087 
 
 " Obstructions in line of . 648 
 
 .837 
 
 " Point of 
 
 646 
 
 " Reversed .... 
 
 640 
 
 " Simple 
 
 640 
 
 " To lay out with transit 
 
 646 
 
 " " " without transit . 
 
 651 
 
 Curved rails ..,,.. 
 
 1041 
 
 " track 
 
 1087 
 
 " " Care of 
 
 
 1101 
 
 PAGE 
 
 Curved track. Effects of, upon loco- 
 motives and car 
 wheels 
 
 • 639 
 
 1094, 1099 
 
 . 1093 
 
 775 
 
 851 
 762 
 832 
 1 197 
 1098 
 
 Curves 
 
 " Elevation of . 
 
 " Lining of 
 
 " Office 
 
 *' of short radii. Sub-chords for 
 
 644, 647 
 
 " Parabolic 
 
 " Platting of 
 
 " Problems relating to 
 
 " Trestles on 
 
 " Turnout, Elevation of 
 
 " Vertical 850 
 
 " Widening gauge of . . 1091 
 
 Curving rails 1088 
 
 " Table of middle ordin- 
 
 ates for . . . 1089 
 Cuts (excavation) . , . 856, 912 
 
 D. PAGE 
 
 Danger signals nji 
 
 Datum line 665 
 
 Declination of needle . . .611 
 
 " " " Changes in . 612 
 
 Deduced bearing .... 634 
 
 Deflected line 631 
 
 Deflection angles .... 642 
 " Tangent and chord . 649 
 Degree of curve . . , .643 
 " " " determined by 
 
 middle ordinate 653 
 " " curvature . . . 64a 
 
 Departure 725 
 
 Departures and latitudes. Platting 
 
 by (see Latitudes) . . . 723, 753 
 
 Direct leveling .... 656, 663 
 
 Distance across river. To find . . 841 
 
 Ditches, Specifications for . . 862 
 
 " Surface .... 966 
 
 Ditching 1052 
 
 Divisions 869 
 
 " engineer. Authority and 
 
 duties of . . . 869 
 
 Double centers 630 
 
 " longitudes . . . 726 
 
 " " Areas found by 727 
 
 " track work, Specifications 
 
 for 861 
 
 Dowels 1202 
 
 Drag scraper, Use of, in excavation 921 
 
 Drainage of streets .... 734 
 
 " " track .... 1052 
 
 " " tunnels .... 950 
 
 Drawing, Topographical . .776 
 
INDEX. 
 
 PAGE 
 
 Drawings, Specifications relating^ to 1213 
 
 Drift bolts iigg 
 
 " Holding power of . . 1201 
 
 " Table of weights of . 1201 
 
 Drill bits 932 
 
 " Churn 928 
 
 " Jumper 928 
 
 " Percussion .... 929 
 
 Drilling by hand, Cost of . . 928 
 " percussion drills, Cost 
 
 of 929 
 
 Drip holes for trestle mortises . 1182 
 
 Driver hammer 993 
 
 E. PAGE 
 Earth, how considered in excava- 
 tion 862 
 
 Earthwork 912 
 
 Easterly corner of a survey, Ex- 
 treme 729 
 
 Economy of railroads . . . 814 
 
 Elevation 65s 
 
 " of curves . . . 1094, 1099 
 " Three processes of deter- 
 mining .... 656 
 Embankments, Connection of 
 
 trestles with . 1207 
 '* Paving of . . 969 
 
 " Provisions for set- 
 
 tling . . 861,977 
 " Seeding and repair- 
 
 ing of . . . 1074 
 Engineer corps in charge of con- 
 struction . . . 869 
 " corps. Routine work of . 970 
 " Division .... 869 
 " Resident .... 869 
 Engineer's chain .... 613 
 " " Errors in reading 614 
 " transit . . . .631 
 
 Estimates 1017 
 
 " Final 1027 
 
 " Monthly . . . 866, 1025 
 " Preliminary . . . 854 
 Excavated material of tunnels, Re- 
 moval of 95a 
 
 Excavation 913 
 
 " Foundation . . . 862 
 
 " of rock, Cost of . . 926 
 
 " " tunnel. Measurement 
 
 of . . . . 961 
 
 " Specifications for . 862 
 
 " Tunnel . . . .863 
 
 " " Cost of . . 964 
 
 Excavator, Steam .... 923 
 
 Exhaust fans 964 
 
 PAGE 
 
 Expansion and contraction of rails 1043 
 
 " shims .... 1044 
 
 Explosives used in tunneling . . 948 
 
 Exterior angles 601 
 
 *' *' of a triangle . . 605 
 
 Extrados of an arch . . . .886 
 
 P. PAGE 
 
 Factors of safety . . . 1249, 1250 
 
 Fans, Exhaust 964 
 
 Fence, Building of . . . . 1075 
 " Material for one mile of . 1078 
 
 Field books 654 
 
 " " for land surveying , 709 
 
 " profiles 842 
 
 Filling of retaining wall . . " . 899 
 
 Fills 856 
 
 Final grade lines. Establishment of 846 
 
 " levels of railroad line . . 846 
 
 " location of line . . . 843 
 
 Fire protection for trestle . 1210, 1218 
 
 Focusing telescope .... 623 
 
 Floor system of trestles 1186, 1231, 1233, 
 
 1236, 1238, 1240, 1242, 1246 
 
 Footwalks for trestles . . . 1210 
 
 Foresight, To prolong a line by . 630 
 
 Foundations for arch culverts . 889 
 
 " " bridges . . .982 
 
 " " " Rock and 
 
 concrete 98a 
 " " framed bents . 1177 
 
 " Masonry . . .1178 
 
 " Pile . . . .987 
 
 " Pneumatic caisson . 992 
 
 Framed bents 1177 
 
 Framing, Specifications for . 866, 1215 
 Friction on retaining walls . . 907 
 
 Frog angle 1104 
 
 " crotch. Location of . . 1120, 1143 
 
 " distance 11 27 
 
 " Keyed 1106 
 
 " number 1104 
 
 " Plate 1105 
 
 " point ...... 1 103 
 
 Frogs II03 
 
 " Crossing 1109 
 
 " Laying of, in track . . J«39 
 
 " Replacing . . . .1110 
 
 " Spring-rail . . . .1107 
 
 " Stiff ...... 1105 
 
 Frontage, Water . . . .703 
 
 Frost, Guard against . . .901 
 
 a. PAGE 
 
 Gauge of curves. Widening . . 1091 
 
 " Tide 692 
 
 " Track 1047 
 
INDEX. 
 
 XI 
 
 PAGE 
 
 Gauging track 1047 
 
 Geometry of circle .... 640 
 Grade in tunnels .... 955 
 
 " line 672 
 
 " Rate of 672 
 
 " lines, Changing of . . 850 
 
 *' " Final . . . .846 
 
 " stakes ..... 977 
 
 Grades for town sites . . . 734 
 
 Gradients of railroads . . . 827 
 
 Grading road bed .... 86i 
 
 Gravel as a destroyer of weeds . 1072 
 
 " Cost of . . . . . 1070 
 
 " pits ..... 1070 
 
 Grillage 988, 1179 
 
 Grip of bolts 1203 
 
 Grout and mortar .... 865 
 
 Grubbing right of way . . 860, 876 
 
 Guard rails of trestle . . .1192 
 
 " " turnouts . . . 1102 
 
 " on short curves . . 1092 
 
 Guard stake 646 
 
 Guards, Cattle 883 
 
 H. PAGE 
 
 Hammer, Striking force of . . 1004 
 Handcars .... .1149,1153 
 
 " level 674 
 
 " " Use of in reconnaissance 816 
 Heading of tunnel . . . 946, 948 
 
 Heel of frog 1103 
 
 " " switch 1102 
 
 Holes, Drip 1182 
 
 Homologous sides, points, etc. . 603 
 
 Hoops for piles 1006 
 
 Horizontal angles. Measurement of 631 
 Hydrographic surveying . . 690 
 
 I. 
 
 Indirect leveling 
 Inspection of materials 
 
 " " track . 
 
 " " trestles 
 Interior angles . 
 Intersection, Angle of 
 
 " of tangents 
 
 Intrados of an arch . 
 Iron details of trestles 
 
 PAGE 
 656, 682 
 
 . 866 
 1 148, 1155 
 1218, 1226 
 
 . 601 
 
 • 639 
 
 • 638 
 . 886 
 
 . 1198 
 " in trestles. Specifications for 1217 
 
 J. PAGE 
 
 Jack stringers 1190 
 
 " Track 1049 
 
 Jacob's staff 608 
 
 Jim Crow 1040 
 
 Joint ties. Location 01' . . 1036 
 
 PAGE 
 
 Joints of arches. Pointing of . .892 
 " Preservation of . . . 1212 
 
 " Stringer 1188 
 
 " Track 1036 
 
 Jumper drill 928 
 
 K. PAGE 
 
 Keystone of arch .... 886 
 
 " " " Depth of . . 887 
 
 King-rod truss 1257 
 
 Lag screws 
 
 " " Washers for 
 Latitude of a line 
 
 " " point . 
 
 " Parallels of 
 Latitudes and departures 
 
 Lettering of compass 
 
 " " maps 
 
 Level cuttings . 
 " Hand 
 
 PAGE 
 
 . 1203 
 
 . 1205 
 
 • 72s 
 
 • 717 
 
 • 693 
 
 • 717 
 
 Applica- 
 tions of, 
 to plat- 
 ting 723, 753 
 . 607 
 . 810 
 . 856 
 . 674 
 
 " " Useof in reconnaissance 816 
 
 " Locke 674 
 
 " notes 669 
 
 " party (railroad survey) . 667, 824 
 
 " surface 655 
 
 " Y 656 
 
 " " Adjustments of . . . 658 
 
 " " Sensibility of . . . 661 
 
 " " Use and care of . . . 661 
 
 Leveling ... • • 6S5 
 
 •' Barometic . . . 656, 688 
 
 " Direct 656 
 
 " Examples in . . .663 
 " Indirect . . . 656, 68a 
 " Necessary degree of accu- 
 racy in ... . 669 
 " Sources of error in . . 668 
 " Track . . . . i«49 
 
 Levels, Check 666 
 
 Final 846 
 
 " for tunnels .... 960 
 
 " of transit .... 624 
 
 Lighting of tunnels .... 965 
 
 Line, Angle .... 631, 762 
 
 " Deflected 631 
 
 " Located 762 
 
 " of collimation .... 623 
 " " preliminary survey . . 76a 
 " " railroad. Choice of . . 819 
 " '* " Subdivisions of . 869 
 
Xll 
 
 INDEX. 
 
 PAGE 
 
 Line, Preliminary and located, rela- 
 
 tive position of 
 
 . 842 
 
 " Random 
 
 . 696 
 
 Lines, Correction 
 
 . 696 
 
 " of survey, How markec 
 
 I • 705 
 
 " Old, how retraced . 
 
 • 709 
 
 " Spur 
 
 . 826 
 
 Load on pile, Computation of 
 
 . 1007 
 
 " Trestle 
 
 . 1007 
 
 Local influence . 
 
 . 6a, 
 
 Located and preliminary lines, 
 
 Rela- 
 
 tive position of 
 
 . 842 
 
 Location, Actual 
 
 . 831 
 
 Final . 
 
 . 843 
 
 " Paper . . 
 
 . 829 
 
 " Problems in 
 
 . 832 
 
 Locke level 
 
 . 674 
 
 Longitude of a line . 
 
 • 72s 
 
 " " point 
 
 • 717 
 
 Longitudes, Double . 
 
 . 726 
 
 " " areas four 
 
 d by 727 
 
 Lost comers, Restoring of 
 
 • 713 
 
 M. PAGE 
 
 Machines, Pile driving . , . 1009 
 " Track laying . . . 1032 
 
 Magnetic bearings, how corrected 612 
 " declination, Changes in . 612 
 
 " meridian . 
 
 
 606,611 
 
 " needle * 
 
 
 . 605 
 
 " variation . 
 
 
 612, 711 
 
 Map. Definition of 
 
 
 • 741 
 
 " of a village 
 
 
 • 7W 
 
 " " final location 
 
 
 . 762 
 
 " railroad " 
 
 
 . 766 
 
 Maps, Contour . 
 
 673 
 
 , 778, 78' 
 
 " Lettering of . 
 
 
 . 810 
 
 " Right of way . 
 
 
 . 860 
 
 " Scale of . 
 
 
 . 8<x, 
 
 " Size of . . . 
 
 
 . 8«, 
 
 " Topographical 
 
 
 • 792 
 
 Marking corners and lines 
 
 
 • 705 
 
 Masonry, Bridge 
 
 
 • 991 
 
 Culvert 
 
 
 . 864 
 
 " First-class 
 
 
 . S64 
 
 " foundations for t 
 
 res 
 
 tie 
 
 bents 
 
 
 . 1178 
 
 " Specifications for 
 
 
 . 863 
 
 Tunnel 
 
 
 . 863 
 
 Material, Bills of 
 
 
 . 1224 
 
 " Care of 
 
 
 • "54 
 
 " required for mile of track 1158 
 
 Strength of 
 
 . 1 
 
 247. 1254 
 
 Meandering 
 
 
 • 703 
 
 Meridian, Magnetic . 
 
 
 606,611 
 
 " Principal . 
 
 . 
 
 • 693 
 
 PAGE 
 
 Meridian, True, how determined . 611 
 Middle ordinate. Degree of curve 
 
 determined by 653 
 " " for curving rails 1089 
 
 Monthly estimates .... 866 
 Monuments (see Town sites) . . 73^ 
 Mortar and grout. Specifications for 865 
 " for arch culverts . . . 892 
 Muck, Removal of ... . 952 
 Mud-sills of trestle . . . "79 
 
 N. PAGE 
 
 Needle, Checking angles by . . 633 
 
 " Declination of . . .611 
 
 Dip of . . . ... 606 
 
 " Magnetic .... 605 
 
 Nipping bar 1046 
 
 Note books 654 
 
 Notes and records. Preservation of 655 
 
 " Compass 619 
 
 " " Form for keeping . 619 
 
 " Field, from paper location . 830 
 " for railroad location, Platting 
 
 of 766 
 
 " for transit survey, form of . 654 
 
 " Level 669 
 
 " " How to keep and check 669 
 " of reconnaissance . . . 816 
 " Topographical . . . 678 
 " " Working up 681, 783 
 Number of frog 1104 
 
 O. PAGE 
 
 Obstacles on curve. To avoid . 648, 837 
 Obstructions in line of curve . 648, 837 
 
 Office curves 775 
 
 " work of railroad survey . 825 
 Old lines. Retracing of . . . 709 
 Ordinate, Middle, how used for de- 
 termining curve .... 653 
 Organization of compass party . 615 
 Outfit, Camp, for reconnaisance 
 
 party 822 
 
 Overhaul 978 
 
 P. PAGE 
 
 Packing blocks 1187 
 
 Paper location. Field notes from . 830 
 
 " " of line of railroad . 829 
 
 " " profile . . .831 
 
 Parabolic curves . .851 
 
 Parallax 610 
 
 Parallel rulers 762 
 
 Parallels of latitude . . .693 
 
 '• Standard .... 696 
 
 Passageway for road . . . 883 
 
INDEX. 
 
 xni 
 
 PAGE 
 
 Pavement 865 
 
 Paving embankments . . . 969 
 Percussion drills .... 929 
 
 Pile bents 1168 
 
 " driving 1002 
 
 " " by direct pressure of 
 
 constant weight . 1003 
 " " by gunpowder p i 1 e- 
 
 driver . . . 1004 
 " " " hammer . . . 1003 
 " " "Nasmyth steam 
 
 driver . . . 1004 
 " " " water jet . . . 1003 
 " " Cost of . . . . 1014 
 
 " " Effect of broomed heads 
 
 upon ..... 1005 
 " " Effect of hammer at- 
 
 tached to rope . . 1005 
 " " formulas . . . 1002 
 " *' machines . . . 1009 
 " " machines, Land . . 1009 
 " " machines, Floating . loog 
 
 "• "■ Methods of . . . 1003 
 " " record . . . .1172 
 *' foundations .... 987 
 " for trestle i.ints. . . . 1007 
 " hoops . . . . • . . 1006 
 
 " shoes 1005 
 
 •' trestles, Loads upon . . 1007 
 
 Piles acting as columns ■ . . . 1008 
 
 " Bearing 1006 
 
 " Creosoted 1216 
 
 " Capping of .... 1175 
 
 " Close ...... 1014 
 
 " Length of 1171 
 
 " Load on ..... 1007 
 
 " Sheet 1013 
 
 " Spacing of .... 1006 
 
 " Specifications for . . 865, 1214 
 
 " Splicing of . . . . 1170 
 
 Pillars, Strength of . . . . 1253 
 
 Plant, Compressed air . . . 945 
 
 Platting angles 741 
 
 " by latitudes and departures 
 
 723. 753 
 
 " compass survey . . 620 
 
 " notes for railroad location 766 
 
 " topography in the field . 677 
 
 Plumbing shafts .... 962 
 
 Pneumatic caisson foundations , 99a 
 
 Pocket book, Trautwine's . . 858 
 
 Point of curve 646 
 
 " frog 1 103 
 
 " tangent .... 646 
 
 Pointing masonry joints . . . 892 
 Polaris .... . . 6ti 
 
 PAGE 
 
 Polar star 611 
 
 Portals of tunnel .... 959 
 Polygons, Similar .... 603 
 Posts, Batter, for trestles . .1183 
 
 " Township .... 705 
 " Whistling . . . .1152 
 Power of telescope ■ . . . . 662 
 Preliminary and located lines, Rela- 
 tive positions of . 842 
 " estimates . . . 854 
 
 " survey (see Reconnais- 
 
 ance) . ... 815 
 
 Preservation of joints of wooden 
 
 trestle 1212 
 
 Pressure, Air, in caissons . . looi 
 
 " on retaining walls . . 908 
 
 Principal meridian .... 693 
 
 Prismoidal formula .... 1018 
 
 Profiles 671 
 
 " Field 842 
 
 " Paper location . . . 831 
 
 Protection by cribs .... 865 
 
 " work. Classification of . 966 
 
 Public lands, Surveying of . . 693 
 
 Pump, Sand 994 
 
 Q. PAGE 
 
 Quantities 856 
 
 " Estimate of . . . 1017 
 
 Quantity book .... 1017, 1022 
 Queen-rod truss .... 1269 
 
 R. PAGE 
 
 Rail bender 1040 
 
 Railroad location .... 813 
 
 " " Map of . . . 766 
 
 Railroads, Economy of . . . 814 
 
 Rails 1038 
 
 " Curved 1041 
 
 " Curving of .... 1088 
 
 " Cutting of 1150 
 
 " Difference in length of inner 
 
 and outer .... 1087 
 " Drilling of .... 1150 
 " Expansion and contraction of 1043 
 " Handling of ... . 1038 
 " of different heights, how con- 
 nected 1 149 
 
 " Spiking of .... 1045 
 
 *' Straightening .... 1039 
 " Weight of, for mile of track .1139 
 
 Random line 696 
 
 Range (of townships) . . .693 
 
 Ranger 969 
 
 Rate of a grade line . . . .672 
 
 Receiver, Air 934 
 
 Reconnaissance 813 
 
XIV 
 
 INDEX. 
 
 PACK 
 
 Reconnaissance, Notes and records 
 
 of . . . .816 
 
 " Use of hand level in 816 
 
 Referencing transit points . . 844 
 
 Refuge bays for tresties . . , laog 
 
 Residency 869 
 
 Resident engineer, Authority and 
 
 duties of 870 
 
 Retaining wall 899 
 
 " " Surcharged . . 903 
 
 " " Theory of . . 905 
 
 Retracing old lines .... 709 
 
 Reversed curve 640 
 
 Ridge lines 777 
 
 Right of way 859 
 
 " " maps .... 860 
 
 Rise of an arch 886 
 
 Risks 1219 
 
 Road bed, Preparation of . . 1031 
 
 " machine, Use of in excavation 913 
 
 Roads i2i8 
 
 Rock excavation . . . 862, 926 
 
 " foundations for bridges . 982 
 
 " " " trestles . 1181 
 
 Rod, High or long . . . .663 
 
 Rods, Target 662 
 
 Route, Choice of .... 819 
 " Conditions determining . 815 
 
 Rubble walls 898 
 
 Rulers, Parallel . . . .762 
 
 S. PAGE 
 
 Safety factors .... 1249, 1250 
 
 " switches 1116 
 
 Sand pump 994 
 
 Scale of map 809 
 
 Scraper work. Cost of . . 919, 921 
 
 Seasoning of cross ties . . . 1030 
 
 Secant parallel lines .... 601 
 
 Section buildings .... 1990 
 
 " dwelling houses . . . 1292 
 
 " lines. Running . . 700 
 
 '• or mile posts . . . 859 
 
 " records 1157 
 
 Sections, Inspection of from car or 
 
 engine .... 1148 
 
 " of line of railroad . . 859 
 
 " of townships . . . 693 
 
 Sensibility of Y level . . .661 
 
 Separators . . . . . 1187 
 
 Settling of embankment. Provision 
 
 for 861, 977 
 
 Shaft lining 950 
 
 " of tunnel. Plumbing . . 962 
 Shafts for tunnels .... 950 
 Sheet piles 1013 
 
 Shimming of track 
 Shoes for piles . 
 Shore lines . 
 Side tracks 
 Sights of compass 
 Signals, Danger 
 Signs, Location of 
 " Conventional, 
 raphy . 
 Similar polygons 
 Similitude, Ratio of 
 Simple curve 
 
 used 
 
 PAGE 
 
 . 1080 
 . 1005 
 78fi, 7<)o 
 • 1057 
 . 606 
 . 1151 
 . 1 1 52 
 
 m topog- 
 
 • 78g 
 
 . . 603 
 
 . . 603 
 
 640 
 
 Single track work. Specifications for 861 
 Sliding of retaining walls . . 904 
 Slope angles . ' . . . . 677 
 
 " board 674 
 
 " stakes. Setting of . . . 870 
 Slopes, Right and left . . .676 
 
 Snow. Bucking 1084 
 
 " Clearing ditches and culverts 
 
 of 1082 
 
 " Clearing switches of . . 1082 
 
 " fences 1083 
 
 " plow, Preparing track for . 1082 
 " Prevalence and effects of . 1081 
 
 " reports 1082 
 
 Soffit of an arch . . . .886 
 
 Sounding 690 
 
 Span of an arch .... 886 
 
 " " bridges, how measured . 979 
 Spandrel of an arch .... 886 
 Specifications for grading and 
 
 bridging . 860 
 
 " " wooden trestles 1213 
 
 Spikes, Boat .... 1198, 1200 
 
 Cut 1198 
 
 " Number of, for mile of track 1160 
 " Pulling of .... 1047 
 " Tables of sizes and weights 
 
 of ..... TI99 
 
 Spiking bridge ties .... 1046 
 
 " rails 1045 
 
 Splicing of piles .... 1170 
 
 Split switches 1115 
 
 Spread of frog 1103 
 
 Springers of an arch . . . 886 
 
 Springing lines of an arch . . 886 
 
 Spur lines 826 
 
 Stadia measurements . . . 682 
 
 Stakes, Grade 977 
 
 " Slope, setting of . . . 870 
 
 Standard parallels .... 696 
 
 " trestle plans . . 1230 
 Star, Polar . . . . . .611 
 
 Station, Most easterly or westerly, 
 
 how found . . 729 
 
INDKX. 
 
 XV 
 
 PAGE 
 1281 
 614 
 6.4 
 1274 
 
 923 
 1004 
 991 
 967 
 1254 
 1254 
 1247 
 
 1255 
 1253 
 
 Stations, Coaling: 
 
 " Distance apart of 
 
 " Numbering of . 
 
 " Water . 
 Steam excavator 
 " pile driver 
 Stone for bridge masonry 
 Streams, Changing channels of 
 Stren'gth of materials, Crushing 
 
 " " " Shearing 
 
 " " " Transverse 
 
 " " wood in tension . 
 
 " " wooden pillars 
 
 Striking force of hammer of pile 
 
 driver 1004 
 
 Stringer joints . 
 
 Stringers of trestle . . . .1187 
 
 " Packed . . . .885 
 
 " Size of .... iiQo 
 
 Stub switch iiii 
 
 Sub-chords for curves of short radi 
 
 644, 647 
 Subdivisions of line of railroad 
 
 Sub grade 
 
 Sub-sills of trestle 
 Sub-station .... 
 
 Supplement of an angle . 
 Surcharged walls 
 Surface ditches .... 
 
 Surfacing of track . . . 1048 
 Survey, Balancing of 
 
 " Preliminary (see Recon 
 
 naissance) . , . 815 
 
 " Testing of . . . . 720 
 
 Surveying, Compass . . . 605 
 
 " Hydrographic . . 690 
 
 " public lands, United 
 
 States system of . 693 
 
 " Railroad . . . 823 
 
 " Topographical . 673, 824 
 
 " Transit . . . .621 
 
 Surveyor's compass .... 605 
 
 Sway-bracing of trestles . . . 1195 
 
 Switch, Derailing .... 1121 
 
 " Facing 1116 
 
 " How to lay out . . . 1133 
 
 " Lap 1123 
 
 " Lorenz 11 18 
 
 " rails IIII 
 
 " rods IIII 
 
 " Split or point . .1111,1115 
 
 " stand 1113 
 
 " Stub IIII 
 
 " Three-throw . . .1119 
 " Throw of . . . iioa, 1113 
 
 loss 
 1179 
 647 
 602 
 
 903 
 
 966 
 1073 
 722 
 
 Switch ties, Number of, for given 
 switch 
 
 " ties. Rule for length of 
 
 " " Tamping of 
 
 " timbers 
 
 " " Three-throw 
 
 " Trailing 
 Switches 
 
 " Automatic, for turnouts 
 
 " How used . 
 
 Safety . 
 
 "39 
 1 140 
 1141 
 "3) 
 1141 
 1116 
 IIII 
 1 124 
 "53 
 . 1116, 1118 
 
 PAGE 
 . 1 141 
 
 • 649 
 ■ 645 
 . 646 
 
 Tamping of switch ties . 
 Tangent and chord deflections 
 " distances .... 
 " Point of ... . 
 " To swing to pass through 
 
 a given point . . . 840 
 
 Tangents, Intersection of . . 638 
 
 " Platting angles by . 751 
 
 Tanks, Water 1278 
 
 Target rods 662 
 
 Telescope, Focusing of . . . 623 
 
 "■ of transit . . . 622 
 
 " Power of . . . . 66a 
 
 Tensile strength of wood . . 1255 
 
 Terminals, Arrangement of . . 1145 
 
 " of railroad . . . 813 
 
 Test holes 992 
 
 Testing a survey .... 720 
 Throw of switch .... 1103 
 
 Throat of frog 1103 
 
 Tide gauges 692 
 
 Tie account 1066 
 
 Ties, Bedding 1035 
 
 Cross 1029 
 
 " Seasoning . . . 1030 
 
 Creosoted 1216 
 
 Directions for placing in track 1064 
 Disposition of old . . 1066 
 
 Distributing .... 1034 
 Estimating for repairs . . 1065 
 
 Joint 1036 
 
 Number of, for mile of track . 1159 
 
 Track 1063 
 
 Trestle 1191 
 
 Timber, Rule for measurement of 1226 
 " Specification for . 866, 1213 
 
 '* used in bridges . . 1247 
 
 " " trestles, etc.. Speci- 
 
 fications for. . 1213 
 Timt>ering of tunnels . . 955 
 
 Toe of switch iioa 
 
 Tongue of frog 1103 
 
XVI 
 
 INDEX. 
 
 PAGE 
 
 Tool house i2<)o 
 
 Tools, Care of 1153 
 
 " Trestle inspector's . . 1228 
 Topographer's notes, Form of . 678 
 Topographical drawing by level 
 
 contours . 777, 779 
 '* drawing by lines of 
 
 greatest slope 777, 786 
 " drawing by shades 
 
 from vertical light 
 
 777. 788 
 
 " drawi ng, Conven- 
 
 tional signs used in 789 
 " drawing . . . 776 
 
 " '* Systems of 777 
 
 " survey . . 673, 824 
 
 " " of town sites 735 
 
 673 
 
 Topography 
 
 Colored 
 
 Conventional signs used 
 
 in . . . 
 Platting, in the field 
 
 Township 
 
 " divisions . 
 " lines, how run . 
 " posts, how placed and 
 marked . 
 Town sites and subdivisions . 
 Track, Ballasting of . 
 bolts. Loose . 
 " Removal of . 
 " Straining of 
 Bridge approaches of . 
 Care and maintenance of 
 centers . 
 Curved . 
 Drainage of . 
 gauge 
 inspection 
 jack 
 joints 
 laying 
 
 " machines 
 " outfit . 
 level 
 
 Lining of 
 Old, work on 
 Raising of 
 Repairs to 
 Shimming of 
 Surfacing 
 ties 
 Tunnel . 
 
 Tracks, Side 
 " Y . . 
 
 Track work, Fall 
 
 1050, 
 
 1060, 1073. 
 
 1063, 1075 
 
 806 
 
 789 
 677 
 
 <593 
 694 
 696 
 
 705 
 733 
 1069 
 1062 
 1062 
 J061 
 1062 
 1058 
 1032 
 1087 
 1052 
 1047 
 "55 
 1049 
 X036 
 1029 
 1032 
 1033 
 1099 
 1150 
 io63 
 1070 
 1079 
 1080 
 1048, 1073 
 1063 
 955 
 1057 
 1126 
 1073 
 
 Track work, General instructions 
 for ... . 
 " in tunnels 
 
 " Spring .... 
 
 " Summer 
 
 " Winter .... 
 
 Transit, Adjustments of . 
 
 " Care of .... 
 
 " Directions for using . 
 " Engineer's .... 
 " notes. Form of . 
 " points. Referencing . 
 Transverse strength of materials . 
 Trautwine's Pocket Book 
 Traverse tables .... 
 
 Trestle, Connection of, with em- 
 bankment 
 " Foot walks for 
 " foundations of crib work . 
 *' " " grillage 
 
 " " " loose rock . 
 
 masonry 
 solid rock 
 
 1148 
 965 
 1058 
 1063 
 1079 
 626 
 629 
 629 
 621 
 654 
 844 
 1247 
 858 
 718 
 
 1207 
 1210 
 1 180 
 1179 
 1181 
 1 178 
 1181 
 1 192 
 
 guard rails . 
 
 loads ..... 1007 
 
 Protection of, against fire 
 
 1210, t2t8 
 Refuge bays for . . . 1209 
 Single track pile . . 1230 
 
 Plan of 1230 
 
 specifications , . . 1213 
 Standard double track pile, 
 
 Boston & Albany R.R. . 1238 
 Standard frame, Oregon & 
 
 Washington R.R. . . 1240 
 Standard framed, Cleve- 
 land & Canton R.R. . 1235 
 Standard framed, Ohio Con- 
 necting R.R. . . . 1237 
 Standard framed, Penn- 
 sylvania R.R. . 
 stringers 
 Sway-bracing of 
 ties, Arrangement of 
 
 Trestles 
 
 Cost of . 
 
 Average life of . 
 Bracing of . 
 Classes of . . . 
 Compound timber 
 Creosoted 
 Erection of . 
 Floor system of . 
 Framed 
 
 " Dimensions of 
 Inspection of 
 
 • >33ta 
 
 . 1187 
 . 1195 
 . 1 191 
 . 1 163 
 1164, 1166 
 . 1163 
 
 • "95 
 . 1166 
 
 • "35 
 . 1216 
 . 1211 
 . 1 186 
 . 1166 
 . 1246 
 
 i2i8, 1226 
 
INDEX. 
 
 XVU 
 
 PAGE 
 
 Trestles, Iron details of . . . 1 198 
 " on curves .... 1197 
 
 " Pile 1166 
 
 " Technical names of parts 
 
 of 1167 
 
 Triangles, Equal .... 601 
 " Similar .... 603 
 
 Triangulation 634 
 
 " Span of bridges meas- 
 
 ured by . . . 979 
 
 True meridian 611 
 
 Truss, King rod .... 1257 
 
 " Queen rod .... 1269 
 
 Tunnel, Alinement and levels for . 960 
 " Bench of . . . 946, 948 
 " Centers of . . . . 959 
 " Drainage of ... 950 
 
 " driving . . . .945 
 
 " " Methods of . . 946 
 
 " " Plant required for 945 
 
 " " Progress in . . 965 
 
 " Excavated material of, how- 
 removed .... 952 
 " Excavation .... 863 
 " " Cost of . . 964 
 
 " " Measurement 
 
 of . . . 961 
 " Explosives used in driving 948 
 " Grade of ... . 955 
 " Heading of . . .. 946, 948 
 " heading, drilling, and 
 blasting .... 
 " Laying out surface line of 
 " Lighting of . 
 " lines, Curved 
 " masonry 
 " Measuring line of 
 " Portals of . . . 
 " sections 
 
 " shafts .... 
 '• " Plumbing of 
 
 " Stationing of 
 " Timbering of 
 " tracks. Care of . 
 " Ventilation of 
 
 Tunnels 
 
 Turning points .... 
 
 Turnouts 
 
 " Automatic 
 
 Turntables .... 
 
 U. PAGE 
 United States system of surveying 
 public lands 693 
 
 946 
 935 
 965 
 941 
 863 
 938 
 959 
 944 
 950 
 962 
 941 
 955 
 955 
 963 
 935 
 66s 
 1127 
 1124 
 1285 
 
 Valley lines 
 
 PAGE 
 
 • 777 
 
 " Advantages of, for rail- 
 roads .... 820 
 Variation, Magnetic . . . 612, 711 
 Ventilation of tunnels . . . 963 
 
 Verniers 625 
 
 Vertical angles 638 
 
 " curves 850 
 
 Voussoirs of arches .... 886 
 
 W. PAGE 
 
 Wales of cofferdam .... 984 
 
 Wall, Retaining 899 
 
 •' Rubble 898 
 
 " Wing .... 880, 89s 
 
 Washers 1205 
 
 Washouts 1059 
 
 Watchman's shanty .... 1292 
 
 Water checks 667 
 
 " columns 1280 
 
 " frontage 703 
 
 " jet. Use of in sinking piles . 1003 
 " supply, Source of . . . 1275 
 
 " stations 1274 
 
 " tanks 1278 
 
 Weeds, Cutting and mowing . . 1067 
 " Destroyed by gravel . . 1072 
 Wheelbarrow work. Cost of . . 914 
 Wheeled scraper. Use of in excava- 
 tion 919 
 
 Whistling posts. Location of . . 115a 
 Wing walls of culvert . . 880, 895 
 
 Wings of frog J103 
 
 Witness trees for land corners . 713 
 Wood, Strength of ... . 1254 
 Wooden pillars. Strength of . . 1253 
 Work, Average daily, of a man . 1158 
 Work train service .... 1155 
 
 Y. PAGE 
 
 Y level, Adjustments of . . .658 
 
 " Sensibility of . . .661 
 " Use and care of . . . 661 
 
 Y tracks 1126 
 
 Yard work 1072 
 
 Yards 1145 
 
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