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Do^not deface books by marks and writing. Cornell University Library The original of tiiis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924004601542 ROCK DRILLING WITH PARTICULAR REFERENCE TO OPEN CUT EXCAVATION AND SUBMARINE ROCK REMOVAL BY RICHARD T. DANA and W. L. SAUNDERS DATA COMPILED BY CONSTRUCTION SERVICE COMPANY FI RST EDITION FIRST THOUSAND NEW YORK JOHN WILEY & SONS London: CHAPMAN & HALL, Limited 1911 Copyright, 1911, BY RICHARD T. DANA AND W. L. SAUNZ)ERS THE SCIENTIFIC PRESS ROBERT DRUMMOND AND COMPANY BROOKLYN, N. V. INTRODUCTORY The rock drill, perhaps more than any other instrument, except the engineer's transit, is the tool that accompanies the vanguard of civilization, and its contribution to the general economy of construction, its effect upon the cost of rock work, and its influence on standard engineering methods, have been enormous. In principle it is unique as a machine, and in practice it offers a class of problems which have long deserved special study and a special treatise. It is a machine of many parts, sizes and shapes, and there are many ways of using it, some of which are better than others, and one of whic]i, for the particular purpose in view, is the best of all. To establish the fundamental facts for determining this " best " way for any given conditions, and to place these facts at the disposal of engineers and contractors, the Ingersoll-Rand Company have instituted an investigation into the economics of drilling work, the results of which are herewith presented in the hope that this book will mark a step forward in the effort to place the study of rock drilling upon a scientific basis. While much still remains to be done, it is believed that the present work contains the cream of the available information on the subject, most of which has never before appeared in print. Most of the data was gathered by the Construction Service Com- pany, Consulting Engineers, of New York, and some of it by Mr. Gilbert H. Gilbert, Consulting Engineer; and the whole was worked into its present form by the Chief Engineer of the Construction Service Company, in collaboration with Mr. W. L. Saunders, President of the Ingersoll-Rand Company. No one in the Construction Service Company has any interest, direct or indirect, in any make of steam drills, or in the results IV INTRODUCTORY of the work, except to see that it correctly represents the economic facts, and no effort has been spared to make the book entirely trustworthy as to these facts. Although it has been carefully checked for errors, it is, of course, possible that mistakes may have escaped notice. If any such should be noted by the reader, a memorandum to that effect, mentioning page number and line, addressed to Construction Service Company, 15 William Street, New York City, would be much appreciated. Richard T. Dana. New York, July, 1911. TABLE OF CONTENTS PAGE Introductory iii Chapter I. Blasting and Explosives i Composition of explosives i Power 5 Rapidity of action 6 Facility and cost of detonation ... 7 Applicability to various conditions of work 8 Freezing phenomena 8 Flame from explosion 9 Fumes g Specific gravity 10 Risks 10 Suitability for wet hole work 12 Springing holes 12 Advantages of springing 13 Theoretical disadvantages of springing 14 The cushioning effect of air and water 14 Simultaneous explosions 15 Blasting machines '. 15 Spacing of blast holes 15 Table of cubic yards of material loosened per foot of drill hole with various spacings of holes 16 Chapter II, Drilling on Land rg Power drilling ig Hardness of the rock 20 Sludging characteristics of the rock 21 Jets 23 Theory of the action of the water jet 24 Diagram of quantity of water in gallons per minute required to remove particles of sludge from drill hole 2S Rules for drill jets 30 Irregularities in the rock 3 ^ The use of steam or air 32 Pressure in the boiler or air chamber 34 The diameter of the pipe connection ^4 Length of the pipe connection 3^ Table giving the number of square feet of external area for 100 lineal feet of piping 3 - Number of drills going at once and drawing pressure from the same reservoir ^^ vi TABLE OF CONTENTS rAGE Diameter of the drill cylinder 36 Stroke of the piston. 36 Convenience of the arrangement for changing bits on each machine.. 38 The weight of the drill itself 38 Depth of hole 38 Table giving vi^eight in pounds of octagonal drill steel 39 Diameter of holes 40 Rate of decrease in the diameter of successive bits 41 Shape of the bit 41 Sharpening and tempering bit 47 Nature of the drill steel 50 Skill of the blacksmith 5a Blacksmith's coal 5r The direction of the hole 51 Chapter III. Drilling on Land {Continued) 52 \ Comparative costs of operation by steam and compressed air 52 Typical cost of operation of six-drill plant and total cost of operating one drill from a steam boiler direct 52 Typical cost of operation of 10-12 drill compressor plant and total cost of operating one drill with compressed air 53 The amount of mucking unnecessary 53 Diagram showing cubic feet of free air to run from 1-40 rock drills 54 The cost of power 54 Table A, of brake or delivered H.P. required to compress one cubic foot of free air per minute to a given gauge pressure 56 Table B, Steam volume and temperature at given pressures 56 Loss of energy in steam pipes by radiation 57 Time study and costs of drilling with steam and air 58 Diagram showing cost of drilling rock, steam boiler direct 60 Diagram showing cost of drilling rock using compressed air 61 Diagrams of cutting speed in various materials with and without jet. . 62 Diagram showing time to change steel. 63 Diagram showing time to move and set up drill for one hole 63 Directions for using cost curves 64 ' Estimating the cost of drilling on proposed work 64 Checking up the cost of drilling on a job under way 65 Standard rates on drj' driUing 66 Experience table of cost of drilling 67 Experience table of cost of blasting and amount of explosives 71 Chapter IV. Drilling on Land {Continued) 75 Livingstone improvement of the Detroit River, cofferdam work 75 Drills 79 Superintendence. 86 Moving plant 87 The traction drill. 87 The cable cars 90 Table shovidng summary of costs 91 Report blank used 97 TABLE OF CONTENTS vii PAGE Chapter V, Drilling on Land {Contintied). D. L. & W. Cut-ofp 99 Section No. 3 100 Section No. 6 107 Section No. 7 115 Chapter VI. Drilling on Land {Continued) 125 Browneil Improvement Co., Thornton, 111 125 Duluth Crushed Stone Co., Duluth, Minn 132 Chapter VII. Drilling on Land {Continued) 143 Contract No. 25 on N. Y. Water Supply Catskill Aqueduct 143 Chapter VIII. Drilling on Land {Continued) 151 Soudan Mine of Oliver Iron Mining Co., at Towar, Minn 151 Tunnel driving at low cost, Ouray, Colo 152 Large vs. small drilling machines 154 Chapter IX. Subaqueous Drilling 159 Standard rates on subaqueous drill work 159 Observations at West Neebish Channel, St. Mary's River 159 Edwards Brothers' driU boat 171 Chapter X. Subaqueous Drilling {Continued) 180 Operations at Blyth, England 180 Submarine rock excavation, Port Colborne Harbor Works, Welland Canal, Canada 181 Improvement of Oswego Harbor, New York 182 Observations on Livingstone Improvement of the Detroit River 1S4 The drill boat "Destroyer" 187 The driU boat "Exploder" 199 The drill boat "Dynamiter" 209 Chapter XI. Subaqueous Drilling {Continued) 220 Drill boat "Earthquake" 220 The sand pipe 225 Drill boat "Hurricane" 231 Chapter XII. Subaqueous Drilllng {Continued) 244 Buffalo boat, No. 5 244 The mud pipe 253 Buffalo boat, No. 4 260 Buffalo boat, No. -^ 266 Buffalo boat, No. i 269 Chapter XIII. Subaqueous Drilling {Continued) 278 Improving Black Rock Harbor and Channel at Buffalo, N. Y 278 Hay Lake and Neebish Channels, Improvement of St. Mary's River, Mich. Section No. 4 282 Improving Ahnapee Harbor, Wis 284 Ship channel of St, Lawrence River through the Galops Rapids 2S5 Chapter XIV. Subaqueous Drilling {Continued). Improvement James River, Va 290 Cienfugos Harbor, Cuba 291 N. Y., N. H. & H. R. R. improvement, Oak Point, New York City, East River 20, Lovejoy's Narrows, improvement Kennebec River, Maine 297 viii TABLE OF CONTENTS PAGE Chapter XV. Subaqueous Drilling by the Platform Method -. 299 Operations on Black Tom Reef, New York Harbor 300 Chapter XVI. Hints and Suggestions eor Rock Drilling and Blast- ing 303 Hints for estimators 308 Alphabetical Index 310 ROCK DRILLING CHAPTER I BLASTING AND EXPLOSIVES The breaking of rock by drilling and blasting as it is pursued to-day dates practically from NobePs invention of dynamite. The blasting of rock by the use of gunpowder is of course as old as the general use of this agent; but blasting, considered as an economic art to-day, is in an entirely different category from that in which it was before the discovery of nitroglycerin. The operation of blasting is conducted through the explosive force of gases generated either by explosion or by detonation. For clearness in the treatment of what follows it is advisable here to define these terms. An explosion is the result of combustion instituted and propa- gated by high temperature. Gunpowder, which is an explosive mixture, is composed of saltpetre, charcoal and sulphur. Upon being raised to the temperature of combustion, or explosion, these materials combine chemically, and in so doing produce a gas. It is the sudden and powerful expansion of this gas which furnishes the force derived from the explosion. The chlorate powders are another example of explosives proper. It should be be noted that the chemical combination must take place progres- sively, from grain to grain as it were, and is not likely to be caused by a jar or shock unless such shock should be sufficiently violent to generate a spark in the mass. The explosives are comparatively bulky considering the amount of gas that they can liberate, and therefore they require a large hole in the rock in order to introduce a sufficient amount of explosive to break it. The black powders, even when glazed, are decidedly sensitive to moisture, a small 2 ROCK DRILLING amount of which is likely to destroy their efficacy, unless they are charged in waterproof canisters or packages. A detonation may be defined as a disruption caused by syn- chronous vibrations of a wave-like character, but the causes of detonation have not as yet been satisfactorily determined. There are a great many detonating compounds, including the nitric derivatives, such as guncotton, nitroglycerin and dynamite, and the nitro-substitution compounds, such as joveite, masurite, lyddite, bellite, securite, and a host of others. These compounds are definite chemical substances, as distinct from mixtures of several different substances, which are in such condition that a wave- like shock will cause their decomposition into gas. The speed of the wave that can produce this combustion is so great as to make the detonation of large amounts of these substances prac- tically simultaneous, thereby causing a very much more sudden and quick shock than in the case of the explosives proper. Some of these detonating compounds in addition to a shock require a high temperature to set them off, and they then come within the classification of the so-called "safety explosives." Provided that no decided shock be administered, many of the detonating compounds can be entirely burned up without causing a detonation, in contrast to the capacity that gunpowder has of submitting to severe shocks without explosion. On the other hand, dynamite, nitroglycerin, nitrogelatin, and others, are liable to be detonated as a result of a rapid change of temperature, even if that change covers a comparatively small range. When frozen, the dynamites are generally very much more difficult to detonate than under normal conditions, but it often happens that frozen dynamite will be detonated by the breaking of the frozen stick or by a shock which would ordinarily not cause the detona- tion of the warm material. At the thawing point it is generally considered to be in a super-sensitive condition. Dynamite to-day has for its main constituent nitroglycerin with an absorbent, such as wood meal, sawdust, kieselguhr, wood pulp, or wood fibre, or even charcoal, and frequently one or more of the ingredients of the explosive mixtures such as sodium nitrate, sulphur or potas- sium chlorate. A peculiar property of these compounds is that BLASTING AND EXPLOSIVES 3 a powder composed of nitroglycerin with an explosive "base" will have more explosive power than the sum of the explosive powers of the ingredients if fired separately. The composition of a considerable number of the powders in common use to-day is given in the following table from Gillette's "Rock Excavation," an inspection of which in conjunction with the text of this chapter will be of assistance in determining the economic grade of powder for a given purpose: Atlas Powder (75 per cent) Nitroglycerin 75 parts Wood fibre 21 " Sodium nitrate 2 * ' Magnesium carbonate 2 " Rendrock (40 per cent) Nitroglycerin 40 parts Potassium nitrate 40 "^ * Wood pulp 13 " Pitch 7 '' Giant Powder, No. 2 (40 per cent) Nitroglycerin 40 parts Sodium nitrate 40 * ' Sulphur 6 " Resin 6 " Kieselguhr 8 " Stonite (68 per cent) Nitroglycerin 68 parts Kieselguhr. 20 " Wood meal 4 " Potassium nitrate 8 " DuALiN (40 per cent) Nitroglycerin 40 parts Sawdust 30 " Potassium nitrate 30 " Carbonite (25 per cent) Nitroglycerin 25 parts Woodmeal 40^ '* Sodium nitrate 34 " Sodium carbonate J ' * Hercules (40 per cent) Nitroglycerin 40 parts Potassium nitrate 31 '* Potassium chlorate 3 J ' * Magnesium carbonate 10 * * Sugar X5I " 4 ROCK DRILLING ViGORiTE (30 per cent) Nitroglycerin 30 parts Potassium chlorate 49 " Potassium nitrate 7 " Wood pulp 9 " Magnesium carbonate 5 * ' HoKSLEY Powder (72 per cent) Nitroglycerin 72 parts Potassium chlorate 6 " Nuttgalls I " Charcoal 21 " Gelignite (62^ per cent) , ^ <• . 1 .• 1 ,- . • • / Nitrofflvcerin, g6 per cent 05 per cent of blastine gelatin, containing i ^ ,, j/ L ^ ^ & s. ' c> 1^ Collodion cotton, 4 per cent (Sodium nitrate, 75 per cent Sodium .carbonate, i per cent Wood pulp, 24 per cent FoECiTE (49 per cent) Nitrogly( , Collodioi Sodium nitrate, 76 per cent ^j,,. ,- ,.. / Nitroglycenn, 08 per cent c;o per cent of blasting gelatin, containing i ^ ,, ,. . ^ ^ o o ' ^ y Collodion cotton, 2 per cent qo per cent of absorbent, containing -1 ttt t ' ^ i^ •^ ^ Wood tar, 20 per cent I Wood pulp, T per cent JUDSON Giant Poavder, No. 2 (40 per cent) Nitroglycerin 40 parts Sodium nitrate 40 " Resin 6 " Sulphur 6 " Kieselguhr 8 " \'ULCANITE (30 per cent) Nitroglycerin 30 parts Sodium nitrate 52^ " Sulphur 7 " Charcoal 10^ ' ' The dynamites are graded according to the percentage of nitroglycerin that they contain. Thus a ''40% powder'' would be one in which the sticks, weighing one-half pound each, would include one-fifth of a pound of pure nitroglycerin. Dynamite is usually packed in paper cartridges weighing about one-half pound each which will vary in diameter. When ordering, it is customary to specify a size of cartridge that will as nearly as possible fill the drill hole, the commonest size being i J" in diameter BLASTING AND EXPLOSIVES 5 by 8" in length. It is nearly always shipped in 50-lb. boxes, which have a volumetric capacity of f cu.ft. The principal features of the high explosives, which vary with the different products, and which are economically important, are as follows, from Trans. Am. Soc. C. E., Vol. 50, p. 388: 1. Power. 2. Cost, initial price. 3. Rapidity of action. 4. Facility and cost of detonation. 5. Applicability to various conditions of work. 6. Temperature of detonation. 7. Freezing phenomena. 8. Ease of transportation and cost. 9. Ease of storage and cost. 10. Flame from explosion. 11. Fumes and elTects from handling. 12. Specific gravity. 13. Risks; divided into (a) risks from proper handling; and (b) risks from improper handling. 14. Wet hole work. Power. There is no satisfactory way of comparing the power of different explosives from the viewpoint of efficiency in the rock, except by actual tests under working conditions. The effect depends upon three factors: the rapidity of detonation, the volume of gases generated, and the temperature of the gases. When an explosive is inserted into a hole in the rock and the hole sealed up above it the gases generated are necessarily con- tained in the chamber that originally contained the explosive. The higher the temperature, other things being equal, the greater will be the pressure in any given gas; likewise the greater the natural volume under atmospheric pressure the greater the pressure when this volume of gas is liberated in a confined chamber. If there be fissures in the rock through which some of the gas can escape before the rock itself yields, or if the tamping which is intended to seal up the hole yields before the full pressure of the g^ses is developed, the escape of part of the gases will necessarily 6 ROCK DRILLING reduce the amount of useful work correspondingly. For these reasons the theoretical number of cubic feet of gas at atmospheric pressure, and at normal temperature, that would be liberated by the explosion, or detonation, of one cubic foot of explosive is not a useful criterion for measuring the economic value of the material. In certain kinds of seamy rock the gases can be dissi- pated so rapidly through the fissures as to make the slow black powders almost useless. Under such circumstances a quick powder will have an opportunity to shatter the rock before the gases have become dissipated.^ The proper grade of dynamite for such cases is as slow a powder as can be found to do the work without an appreciable waste of gas. In practice to find this substance is not easy, and there seems to be no better way than to experiment with different grades of powder in holes that have been carefully measured and located under as nearly uniform conditions as possible. Most rock excavation is some distance from the base of supplies, and therefore it is expedient to order several kinds of explosives until it has been definitely settled by experiment which grade of powder is the most economic. Where the rock is faulty and variable in structure, as in many of the shales, schists, and granites, the rocky conditions surround- ing one hole may be so different from those surrounding another one near by as to lead to a very confusing set of observations. The only way known to us that has proved successful in such a case is to keep careful and constant records during the whole progress of the work. Each blast will then contribute its share of information and the information will be of more and more value as the work progresses. After a day or two of experiment the approximate cost per cubic yard of rock loosened can be obtained. Rapidity of Action. The slowest acting explosives are the regular black powders, the speed of action increasing through Judson powder, 25% dynamite, etc., up to pure nitroglycerin. This variation of speed in action can be made use of economically ^ Where the word "powder" is used in this text, it should be understood to comprise any of the explosives or detonants. It is the field term for all of them. BLASTING AND EXPLOSIVES 7 in the following ways: "WHiere the rock does not break properly- near the bottom of the holes a higher explosive or detonant can be placed at the bottom of the hole than at the top, and by placing the firing primer at or near the top of the hole the pressure of the gases can be made much greater at the bottom than else- where, thus producing a greater rupture. In this connection it must be thoroughly understood that the pressure of the liberated gases is equal in all directions, and that pressure will produce the most destructive results where it meets with most resistance. When the high explosive is placed at the bottom of the hole, if the primer also be placed at the bottom, the explosion is likely to be so quick as to blow some of the charge out of the hole before the explosive at the top has an opportunity to do its work; if, however, one grade of dynamite be used throughout the depth of the hole the detonation of the whole mass is likely to be so nearly simultaneous as not to affect the result. Following this same idea, it is apparent that the holes which contain a low explosive, like black powder, should be more solidly tamped than those loaded with the high dynamites. It is fashionable on most contract work to use a minimum of tamping when loading dynamite, and the tamping that is used is generally selected at random in a haphazard way. It should be selected with great care from as dense material as can readily be obtained, and it should not be of such material as loose gravel or sand containing a large amount of voids. A mixture of loam or clay with sand makes a good tamping, and where the rock is soft, requiring the use of the low explosives, and the explosive nearly fills the hole, it is frequently economical to use a tamping mixture of three parts of sand to one part of plaster of Paris. The plaster of Paris sets up in a very short time, thus sealing the hole very firmly, and giving an admirable opportunity for the powder to do its work before blowing out. One bag of plaster of Paris of slight cost and six cubic feet of sand will provide sufficient tamping for 90 holes. By the use of this expedient it will often be found possible' to use a lower grade of dynamite than other- wise at a considerable saving in the cost of powder. Facility and Cost of Detonation. The higher grade dyna- 8 ROCK DRILLING mites are much easier to set off than the lower grades; thus it is possible to use a low strength primer with the higher explosives. Applicability to Various Conditions of Work. The gen- eral applicability of a particular grade of explosive is a feature which recommends itself to a great many consumers who are purchasing it in large quantities. By far the commonest grade of dynamite in general use is the 40%, and this is the strength of most general applicability. Like the problem of the weight of a pick or shovel or the size of a locomotive, there is always one best grade to use for any given purpose, and no one grade is economic for general use. In short, as suggested above, in a great deal of work it is highly advisable to use two or more different kinds of powder in the same hole. The 40% dynamite, by virtue of the comparatively small amount of nitroglycerin and the large amount of absorbent or ''buffer," is comparatively insensitive to shock, difficult to detonate, and safe to transport and store. It can be banged along a country road in a springless wagon and it can be hurled in individual sticks down a rock cliff with only occasional accidents from such treatment. It can be used for mud capping, block holing, or for breaking shaley rock and, with indifferent economy, the heavy traps and granites. It can be used to "spring' holes, and for the main charge after the holes have been sprung. In very cold weather the 40% powder is sometimes difficult to detonate without double strength caps. Under these conditions it is advisable to use a higher powder, or to insert the primer in a cartridge of high powder at the top of the hole. Freezing Phenomena, All users of dynamite appreciate that nitroglycerin will freeze, but few of them realize that the tem- perature of freezing is several degrees higher than that of melting snow. It is a common occurrence to hear one of the old-fashioned powder men, of vast experience and a considerable disdain for new-fangled ideas, observe that if the holes are full of water the dynamite cannot possibly freeze in them until the water turns to ice. After standing for an hour or two in water at a temper- ature of 35° F. the dynamite is likely to either not detonate at all or to do so with much less than its normal strength. The first warning of this condition generally comes when a number of BLASTING AND EXPLOSIVES 9 holes "miss" while the others detonate. When this condition obtains it is fairly certain that the holes that did not misfire did not get the benefit of the full strength of the powder. WTien the holes are being loaded just before the powder is placed in the hole, it is frequently customary to blow all the water and small particles of stone out of the hole by means of a steam jet. This steam jet warms up the hole so that the powder can remain therein for some little time before congealing. The precise length of time depends upon the degree to which the hole has been heated, the conductivity of the rock, and the amount of cold water that is flowing into the hole or through the seams of the rock; and also on the length of time that cold weather has obtained before the time of loading. Where the holes are quite deep it takes con- siderable time for the cold to penetrate the rock. The dry powders, such as black powders, Judson, and many of the nitro- substitution class, will not freeze, and investigation regarding their use in freezing weather is highly recommended. The use of many of the latter for industrial purposes is still in the experimental stage. Flame from Explosion. In mining work where fire damp is to be anticipated the flaming powders are an element of grave danger and therefore of high cost. Some of the so-called safety explosives are claimed to be flameless, and if the claim be true, are a valuable discovery in this line. We have, however, as yet not seen convincing proof that the perfectly flameless explosive has ever been developed. It is undoubtedly true, nevertheless, that some powders give a very much hotter flame than others. Fumes. Nitroglycerin, besides being a high explosive, is a powerful heart stimulant, and when the fumes from its com- position are inhaled the resultant effects are usually a severe and sometimes prolonged headache. The same effects will be produced by handling the dynamite cartridges with bare hands in hot weather or whenever the ofly nitroglycerin penetrates the paper of the cartridge. This can be guarded against by wearing leather gloves, but the fumes can hardly be avoided except by the men keeping away from the vicinity of the blast until the fumes have been dissipated. In confined places, such as mines and ill-ventilated tunnels, this necessary time for clearing 10 ROCK DRILLING the air is often a half hour or morej adding an element of cost the amount of which can readily be estimated. To avoid this element of cost the work may sometimes be so laid out that the men, after firing a blast, can be kept busy on some other work for the necessary period. Another method is by means of copious ventilation. One of the reasons why the Simplon Tunnel was driven at record breaking speed was because it was run in two parallel headings, through one of which a tre- mendous amount of air under pressure entered, finding its way out by the other through a system of cross drifts, all but the last one of which were sealed as the work progressed. This method insured a minimum of lost time on account of dynamite fumes and was highly economical. Specific Gravity. The larger the amount of energy stored in a cubic inch of powder the smaller may be the diameter of the drill hole, or the farther the holes may be apart; therefore, other things being equal, the denser powders, as compared with the hghter ones, will often admit of a considerable saving in the collateral operation of drilling. The weight of dynamite per inch of stick is about as follows, and all the grades weigh about the same per stick: Diameter of Stick in Inches. Weight in Pounds per Inch of stick. Diameter of Stick in Inches Weight in Pounds per Inch of stick. I 0.042 0.065 0.094 If 2 2i 0.128 o.t68 0.212 Risks. Accidents are always costly, and as an element of false economy the risk from any method of handling powder should be taken into account. The following list of some of the dangers arising from the use of dynamite points a moral which need not be elaborated. The list includes only actual causes that have been known to produce accidental detonations. (a) Dangers inevitable, even with reasonable care: 1. Spontaneous explosion in storage. 2. Lightning. BLASTING AND EXPLOSIVES 11 3. Part of charge failing to go off and remaining undis- covered until exploded either by the sun's rays or by being struck by a tool. 4. Train wreck. 5. Drilling near missed hole. 6. Flame; fire damp. (b) Dangers incidental to the handling of dynamite as prac- ticed every day: 1. Dropping stick or box. 2. Hole too small for cartridge; ramming down cart- ridge. 3. Ramming too hard, or ramming vnth metal bar. 4. Deepening missed hole. 5. Returning to relight fuse. 6. Testing the end of a hole with an iron bar after a blast to see if any of the charge remains. 7. Forcing primer into cartridge. 8. Ramming in the first ball of tamping clay. 9. Breaking a cartridge when near the freezing point. 10. Stepping upon particles of explosive. 11. Thawing in front of kitchen fire. 12. Thawing in tin over fire. 13. Thawing in men's boots or shirts. 14. Thawing in an oven. 15. Hot water containing dynamite placed on a black- smith's fire. 16. Thawing with candle. 17. Reheating water which has been used in thawer. 18. Throwing on ground water which contains nitro- glycerin from thawing cartridges. 19. Rubbing cartridge in hands to complete thawing. 20. Cartridge left in pocket of garment hung before fire to dry. 21. Having cartridge and primer near each other when not in use. 22. Destroying material not considered desirablp. 12 ROCK DRILLING Suitability for Wet Hole Work. When immersed in water nitroglycerin will leave a stick of dynamite and its place will be taken by the water, owing to the greater affinity that the water has for the mechanical dope, so that in wet holes the nitroglycerin powders are not entirely suitable, and although usually they will detonate, they do so with reduced efficiency. This objection does not apply to nitrogelatin. Theoretically, a waterproof cartridge can be made of paraffin paper, but as a matter of practical economics this expedient has not made its way into general use. A waterproof slow-burning powder of low explosive force and great cheapness would be of great value in blasting the softer rocks where water cannot be avoided. Springing Holes. The usefulness of different grades of dyna- mite in the same holes has been pointed out above. A further development of the same idea can frequently be taken advantage of by springing the holes, an operation consisting of detonating a few sticks of high percentage dynamite in the bottom of the hole, thus producing an enlarged and approximately pear-shaped chamber, which then can be filled with an explosive powder to any desired amount. As in the general choice of an explosive, the kind and amount of powder necessary to chamber a hole must be determined by experiment for each particular case. In soft shale, where the lamination plane was inclined to the hori- zontal at an angle of about 50°, two sticks of 40% dynamite were sufficient to form a chamber about the size of a man's head in the bottom of a 10 foot hole. A tamping rod placed in the hole after springing with two sticks would usually descend from 4 to 6 inches lower than before the springing, and it was feasi- ble to get the greater part of a charge of 18 sticks in the chamber. With the hard rocks, where large chambers are desired, it is necessary sometimes to make two or three shots. Thus in East- ern Ohio, Mr. V/. M. Douglas ^ in sandstone work fired first 15 sticks, then 40 and then 80, and finally 130 sticks of 40% dynamite per hole. The chambers were then large enough to hold 45 kegs of black powder. We have sprung 20-foot holes in sandstone. ^ " Rock Work," p. 149. BLASTING AND EXPLOSIVES 13 using for the first shot 2 sticks, for the second 5 sticks, and for the third 20 sticks of 40% powder. In charging sprung holes with black powder it is economical to use a so-called charging tube, which prevents the free running pow(ifer from sticking to the sides of the hole on the way down, or from becoming dissipated in fissures. Advantages of Springing. The cost of springing holes is the cost of supplies, their handling and storage, and the time of the men employed. This work can be done by the regular blasting gang with almost no interruptions to the regular loading, since it is safe to stand within 10 or 15 feet of a hole that is being sprung v/ith light charges. It seems hardly necessary to add that a large number of holes can be sprung at the same time. Each should be lightly tamped with one or two handfuls of clay. If this causes too much of a "shake-down" use less powder but not less tamping. Since the effect of blasting depends upon the explosive power of the generated gases, which press equally in all directions, if the explosive be concentrated at the bottom of the hole, the result will be to more thoroughly shatter the rock in the immediate vicinity of the charge than elsewhere. Where rock is to be excavated with a steam shovel, and particularly where the plane of lamination is at an angle to the horizontal, holes in which the charge is not concentrated at the bottom will frequently leave ridges that prevent the progress of a steam shovel until they have been cleared away by mud-capping or by drilling in front of the shovel while the shovel stands idle. To see thirty men with a steam shovel and two or three trains of cars wait while a drill or two '^get busy" in front of the shovel, is one of the most demoralizing things in construction work. Delays to steam shovels from this cause often run as high as 50 to 60% of the working day, and perhaps no other cause is more conducive to loss of money in this kind of operation. It can usually be eliminated to a large extent by the proper spring- ing of the holes, the rock being almost pulverized for a consid- erable distance from the centre of each charge. The direct economic result from springing lies in the fact that the holes can be placed a much greater distance apart than 14 ROCK DRILLING otherwise, and a low and cheap grade of powder can be used for the rock. A peculiar collateral advantage from this fact should be mentioned. It has been observed that stone used for ashlar masonry is subject to the development of fine cracks when the very high explosives have been used in the quarrying operation. This is particularly true of the marbles. It would seem that the heavy blows of the high explosives cause fine initial cracks which do not appear while the stone is being quarried, and only come to light after it has been for some time in use. For this reason it is essential whenever quarrying dimension stone to utilize the very lowest grade of explosi"\'e possible, and to economically use the low explosives springing is necessary. A further advantage from the use of the springing method lies in the fact that a very small drill hole can be used. As will be shown later, a hole with a diameter of 2 inches costs a good deal less money to drill than one of 3 inches, and there- fore when springing makes a hole with a diameter of if" at the bottom adequately large, it is likely to greatly reduce the drilling cost. Theoretical Disadvantages of Springing. When it is not desired to break up the stone, but to quarry it in large rectangular pieces with as small waste as possible, the holes must be compar- atively small, close together and loaded throughout almost their entire length. Under these circumstances chambering is not feasible. The "practical man" will often urge against springing the theory that the shaking from the springing shots may cause debris to fall into the hole if the rock be soft. We have inves- tigated some cases of such objections, certified to by contractors with great vigor, but have never yet found them justified by the facts. Wherever the chambering method is feasible we have found it to be highly economic. The Cushioning Effect of Air and Water, When the cartridge does not completely fill the hole there is an air space which acts as a cushion to the expanding gases and lessens the sharpness of the blow which these strike at the rock. This condition should be carefully avoided by having the cartridge BLASTING AND EXPLOSIVES 15 of a size to fill the hole, or by carefully shtting the cartridges before loading, except where the powder at hand is of too high a grade for the rock. The grade of powder can be artificially lowered by purposely having such a cushion in the hole, but it should be emphasized that the correct grade of explosive is less expensive than this kind of cushion. A somewhat different effect is produced by a cushion of water. When the hole is full of water the raost economic results are obtained with the powder thoroughly compressed into the hole in the rock. The over- lying water then forms a sort of imperfect tamping. When the powder is not thoroughly packed and is surrounded by water, the cushioning effect is very considerable. Simultaneous Explosions. Most blasting is done nowadays by electric firing, the holes being detonated together. This simultaneous firing, according to Eissler, is 25% more effective in breaking the rock than when holes are fired consecutively. A corollary to this is that the maximum effectiveness can be obtained when the largest number of holes possible is fired together; a second corollary is that it is not economic to buy a low powered blasting machine, or to neglect to have those on hand kept in good repair. Blasting Machines. These are simply hand-operated dyna- mos; they do not require recharging, but with ordinary use should be overhauled once every two or three months. Leaving the blasting machine two or three nights in a damp place will tend to induce short circuiting in the coils, and has frequently been the cause of great expense through partial blasts. These machines should give a current of two or three amperes with an intensity of one volt for each fuse. Where an electric light main of suitable potential is at hand the blasting machine proper can be dispensed with, but an actual experiment should be made before depending upon this method, firing the actual number of fuses to be used in blasts. Spacing of Blast Holes. No absolute rule can be given for the spacing of the holes. The cost of powder per cubic yard of rock may be a little greater if the holes are spaced far apart than otherwise, but not much greater, whereas the cost per cubic yard 16 ROCK DRILLING of rock excavated for drilling and blasting will vary inversely as the square root of the distance between the holes. Thus, if the holes are spaced 6' apart and are lo' deep there will be 13.3 cubic yards excavated per hole. If the distance between the holes is half of this or 3', there will be excavated 3 J yards per hole, or one-quarter the perfornmnce in the former case. In practice, a common rule is to make the distance of a hole back from the face equal to its depth; another rule is to make this distance three-quarters of its depth. In stratified rock the holes can some- tim.es be placed a distance apart considerably greater than their depthj and, when the rock is laminated with a heavy dip, the distance between the holes parallel to the direction of the strike, can be considerably different from the distance in the other direction. Which distance is to be the greater will depend upon (a) The grade of explosive. (b) The friability of the rock in the different directions. CUBIC YARDS OF MATERIAL LOOSENED ] PER FOOT 10' 0" 0.370 0.741 I. II 1.48 1.85 2.22 2-59 2.96 S-33 3-70 96 0-352 0.704 1.06 1. 41 1.76 2. II 2.46 2.82 3-17 3-52 9 ^■333 0.667 1. 00 ^-33 1.67 2.00 2-33 2.67 3.00 3-33 8 6 0-315 0.630 0.944 1.26 1-57 1.89 2.20 2.52 2-83 3-15 8 0.296 0-593 0.889 1. 19 1.48 1.78 2.07 2-37 2.67 2. 96 7 6 0.278 0-556 0-833 I. II 1-39 1.67 1-94 2.22 2.50 2.78 ^70 0.259 0-519 0.778 1.04 1-30 1.56 1.82 2.07 2-33 2-59 ^^6 6 0.241 0.481 0.722 0.963 1.20 1-44 1.69 1-93 2-17. 2.41 *^ 6 0.222 0.444 0.667 0.889 I. II ^■33 1.56 1.78 2.00 2. 22 ! ^ ^ 0.204 0.407 O.61I 0.815 1.02 1.22 1.42 1-63 1.83 2.04 ^50 0.185 0.370 0.556 0.741 0.926 I. II 1-30 1.48 1.67 1.85 -S 4 6 0.167 0-333 0.500 0.667 0-833 1. 00 1. 17 ^•33 1-50 1.67 WJ 4 0.148 0.296 0-444 0-593 0.741 0.889 1.04 1. 19 ^■33 1.48 '§36 0.130 0.259 0.389 0.519 0.648 0.778 0.907 1.04 1. 17 1.30 CIh ^ O.III 0.222 0-333 0.444 0-556 0.667 0.778 0.889 1. 00 I. II 2 6 0.093 0.185 0.278 0.370 0.463 0-556 0.648 0.741 0.833 0.926 2 0.074 0.148 0.222 0.296 0.370 0.444 0.519 0-S93 0.667 0.741 I 6 0.056 O.III 0.167 0.222 0.278 0-333 0.389 0-444 0.500 0.556 I 0.037 0.074 O.III 0.148 0.185 0.222 0.259 0.296 0-333 0.370 6 0.019 0.037 0.056 0.074 0.093 O.III 0.130 0.148 0.167 0.185 o'o" I 2 3 4 5 6 7 8 9 10 Spacing in feet. BLASTING AND EXPLOSIVES 17 (c) The amount and size of fissures. (d) The character of the loading, whether throughout the hole or in chambers. As stated above, no hard and fast rule can be laid down. The accompanying table gives the yardage of rock loosened per lineal foot of hole when the holes are arranged in regular rows. In some large blast firing in France 11.7 cubic yards of rock were loosened with one pound of powder. The rules in this practice were as follows: 1. Distance between powder chambers should equal the thickness of the rock above them. 2. The face left after a blast should be as nearly vertical as possible. 3. With one powder chamber only, the distance from its center to the face of the quarry and to the top of the mass should be equal. OF DRILL HOLE WITH VARIOUS SPACINGS OF HOLES. 4.07 .87 .67 .46 .26 .06 -85 -65 -44 .24 2.04 1.83 1.63 1.42 1.22 1.02 0.815 0.611 0.407 0.204 II 4-44 4.82 S-19 5-56 5-93 6-30 6.67 4.22 4-57 4-93 5-28 5-63 5-9S ^-33 4.00 4-33 4-67 5.00 5-33 5-67 6.00 3-78 4.09 4.41 4-72 5-04 5-35 5-67 3-5^ 3-85 4-15 4.44 4-74 5-04 5-33 3-33 3.61 3-89 4-17 4-44 4-72 5.00 3-11 3-37 3-63 3-89 4-15 4.41 4.67 2. 89 3-^3 3-37 3-61 3-85 4.09 4-33 2.67 2.89 3. II 3-33 3-56 3-78 4.00 2.44 2.65 2-85 3.06 3-26 3,46 3-67 2.22 2.41 2-59 2.78 2.96 3-15 3-33 2.00 2.17 2-33 2.50 2.67 2-83 3-00 1.78 1-93 2.07 2.22 2-37 2.52 2.67 1-56 1.69 1.82 1-94 2.07 2.20 2-33 ^•33 1-44 1-56 1.67 1.78 1.89 2.00 I. II X.20 1.30 1-39 1.48 1-57 1.67 0.889 0.963 1.04 I. II 1. 19 1.26 ^■33 0.667 0.722 0-778 0-833 0.889 0.944 1. 00 0.444 0.481 0.519 0-556 0-593 0.630 0.667 0.222 0.241 0.259 0.278 0.296 0-315 0-333 12 13 14 15 16 17 18 7.04 6.69 6-33 5-9S 5-63 5-28 4-93 4-57 4.22 3-87 3-52 3-17 2.82 .46 .11 1.76 .41 1.06 '.704 '-352 19 41 04 6.67 6.30 5-93 5.56 5-^9 4.82 4-44 4.07 3-70 3-33 2,96 2-59 2. 22 1.85 1.48 I. II 0.741 0.370 20 10 o 96 Q o 8 6 76 ^ 70^ 6 6 2. 60^ 5 6 5- 4 6 4 o 3 6 3 o 2 6 2 o I 6 I o o 6 Spacing in feet. IS ROCK DRILLING One of the most satisfactory rules in blasting is to avoid so loading the holes as to throw much rock into the air. If a dense brown smoke with pieces of rock be thrown high in the air with each blast, the holes are too heavily loaded, or the bulk of the charge was not placed low enough in the hole. CHAPTER II DRILLING ON LAND The problem of drilling is closely related to that of blasting, since primarily the object of the drill holes is to enable the process of blasting to take place . Any method that decreases the number of the holes per cubic yard blasted through increasing the area covered by each hole, will also decrease the cost of drilling nearly in direct proportion to the decrease in the number of feet of hole per cubic yard of rock excavated. Power Drilling. To the casual observer a steam drill hammering away indefatigably and with a tremendous racket seems an instrument peculiarly well adapted for its work and hardly adinissable to criticism as to its performance; but to the expert after careful study and patient investigation the power drill appeals as presenting one of the most dijficitU economic prob- lems to master, one of the most perverse machines to handle, and one of the most complex tools ever invented. To improve on it, however, is another story. In the first place, the economic conditions which govern the drilling problem include the following: 1. Hardness of the rock. 2. The sludging characteristics of the rock. 3. Irregularities in the rock. 4. Whether steam or air is used. 5. Pressure in the boiler or air chamber. 6. Diameter of the pipe connection. 7. Length of the pipe connection. 8. The number of drills working at the same time and draw- ing pressure from the same reservoir. 9. The diameter of the drill cylinder. 10. The stroke of the piston. 10 20 ROCK DRILLING 11. The type of the drill. 12. The weight of the moving parts. 13. The cut-off in the steam chest. 14. The convenience of the arrangement for changing bits on each machine. 15. The weight of the drill and the kind of mounting. 16. Depth of hole. 17. Diameter of hole. 18. The ra.te of decrease in the diameter of successive bits. 19. The shape of the bit. 20. The nature of the drill steel. 21. The skill of the blacksmith. 22. The kind of coal at the blacksmith's disposal. 23. The direction of the hole, 24. The use of water for pouring into the hole. 25. The use of a powerful water jet in the hole. 26. The use of a hollow bit with a water or air jet. 27. The wages of the driller and helper. 28. The amount of mucking necessary. 29. The cost of power, including the cost of fuel. In addition to these are the following, which may be classed as general causes having a peculiar effect upon drilling work: 1. Steam leakage in the neighborhood of the drills and con- densing steam around the men. 2. Wind, in combination with cold weather. 3. Elevation above sea level, or barometric pressure. It is at once apparent that any economic rule for taking into consideration all of these specific factors, with a number of general ones in addition, is enormously difficult to compose. The general effect of each of the above conditions, however, can be predicated with some accuracy, and thus the best pro- cedure for any given case can be determined. Hardness of the Rock. From the diagrams on pp. 60-63, under the caption "Time Study," it is apparent that in the hard rocks and the very soft rocks the actual time of cutting is a very great factor in the total expense, whereas in the medium soft rocks and the very soft rocks under favorable conditions, DRILLING ON LAND 21 the cutting speed is so great as to make actual cutting take up a comparatively small percentage of the total time. The hard rocks require a hea"\^ blow with a sharp tool in order to break them up, and if other conditions are equal, the amount of work necessary to excavate a hole will be pro- portional to the hardness of the rock. Sludging Characteristics of the Rock. When the very soft rocks are reached in the application of this rule the cutting is so fast that the amount of pulverized material or sludge formed is so great as to make a cushion for the bit on the downward stroke and a clog to the bit on the upward stroke. The shales will often form a sludge containing such proportions of large and small particles as to cake on the bit and make it difficult, if not impossible, to draw the bit out of the hole. Two kinds of delays to the action of the drill result. The first, or cushioning effect, prevents the drill from cutting rapidly in the latter part of the run of each bit; the other is that caused by the sticking of the bit. The sludge above the bit settles in the hole about 6 inches above the bottom and not only cakes on the bit but also on the side of the hole, and after a few strokes the bit jams. Under these conditions drilling is one of the most painful proc- esses in the world. The efforts of the driller to loosen the drill by striking it on the steel just above the top of the hole are destructive of tool, equipment, temper, and time. After the drill has become stuck one or more of the following remedies should be apphed: (a) Run a powerful water jet through a pipe down to the bottom of the hole and work up and down. This is very effective in loosening up the bit and will also enable a new bit to descend promptly to the bottom of the hole so that the shank will pass over the head of the bit without the necessity of the helper dismounting and raising one of the legs of the tripod. {b) Strike the drill steel as low as possible with the dolly bar or wrench. (c) Put the dolly bar on the steel and pull as hard as possible while the helper attempts to crank up. 22 ROCK DRILLING ((/) If the material varies much in hardness drop a handful of pieces of cast iron the size of hazel-nuts into the hole. (e) Shut off the pressure, crank up, turn the pressure on again and try to work the bit down into the hole while striking slowly. This must be done with great caution, else the piston will break the cylinder-head casting. (/) With the dolly bar revolve the steel in the hole while the helper is cranking up and, if necessary, help with a little steam or air. (g) WTiile the drill is working churn up and down in the hole with a thin strip of hickory. {/?) Ascertain whether the drill is correctly set up in ahgn- ment with the axis of the hole; if not, correct the position of the drill. It is a pecuharity of the rock-drilling process that the sludge which is formed in the drill hole contains fine and large grains in such proportion that when mixed with a httle water the mass is pasty, and in this condition it retards the cutting process very much. When water is poured into the hole in small quantities it loosens up the sludge and tends to prevent the bit from sticking; but if poured into the hole in comparatively large quantities, say, a quart in granite or 6 quarts in shale, there is a decided tendency for the finer particles of the sludge to rise, while the larger pieces ranging in diameter from about -^q" to nearly Y' (in the case of shale) settle to the bottom, get under the bit and are themselves again pulverized into still finer material, meanwhile greatly obstructing the progress of the drilling. To remove this sludge as fast as it forms is theoretically and practically the best method of hastening the speed of drilling. In the softer shales the amount of sludge formed is so great that water poured into the hole only serves to make a paste that nearly fills the hole itself. When the sludge is very thick, as happens in the shales, the hole must be pumped out once for every foot of progress. One very effective way of overcoming the necessity of pump- ing twice for each bit is to keep churning up and down in the DRILLING ON LAND 23 hole with a hickory wand of the same size as a barrel hoop. The material for these can be bought in small bales in the principal cities. These wooden sticks, worked up and down by the drill runner, have the effect of keeping the sludge stirred up and away from the bit at the bottom of the hole, which results in a great increase in the number of blows per minute, and, con- sequently, in faster cutting. Just how much material they remove from under the bit itself is somewhat problematical, but the general effect in the soft shales is to approximately double the cutting speed. The method is of special advantage in very cold weather when it is not easy to use water jets and when the men like \'ioIent exercise to enable them to keep warm. In warm weather, the physical exertion necessary to work a wand in a lo-foot hole is so great as to make it hard to keep the men at it vigorously; and if not vigorously used the wands are of Httle use. Jets. A jet of water introduced into the hole through a hollow bit or a small pipe is the most effective means of clear- ing away the sludge. The water keeps the material away from the bottom of the hole and allows the drill to cut about three times as fast in the soft rocks as before. It is necessary to have the jet sufficient in pressure and also in volume. If insufficient in pressure the speed of the moving water will not be enough to move the larger particles of stone, while if not in sufficient quantity the water will move the sludge from the point of the bit only to let it settle and cake higher up on the bit. It will then be difficult to get the bit out of the hole at all, and the entire method will be dubbed useless by the '^practical men." Aitken states that in trap rock the use of water reduces the time of drilling by 30%, and this is borne out by the remarka- ble results shown in the diagram on p. 62. These observations apply more particularly to holes with a downward dip. When driving holes that point upward the dry powder has a tendency to run out of the hole. With a rapidly moving drill this is pro- ductive of a cloud of dust which is distressing to the men and obstructive to the work. A jet of air played upon the mouth of the hole is the remedy for this trouble. 24 ROCK DRILLING When the holes are nearly horizontal a jet of air into the hole, rather than the water jet, should greatly economize the process. Always the rule is to get the cut rock away from under the working bit as cleanly and as rapidly as possible. Mr. H. P. Stow 1 reports an experiment in which the same miner drilled three equal shifts of similar holes with the follow- ing performance, using a 2 J" drill: Without water, 32 ft., using ;^S bits. Bailing, 4if ft., using 33 bits. With jet of water, 52 ft., using 37 bits, This is a gain of 30% for bailing, and 62 J% with the jet over the dry holes per unit of total working time. Theory of the Action of the Water Jet. According to the experiments of Rittinger, as described in Engineering Contracting, Yo\. XXIX, p. 84, after a fall of short distance, grains of sand or rock will descend through water at a fixed and constant speed. Up to about 0.4'' in diameter the formula for this speed is as follows : where 7- = speed of fall in inches per second; c^ = diameter of falling grain in inches; G = specific gravity of grain. This formula relates to "average grains" and gives their velocity when falling through still water after they have attained a constant velocity. Rounded grains have a velocity about 10% greater, and flat grains have a velocity of about 20% less than "average grains." In 1894 Prof. Robert H. Richards ^ made public the results of a large number of experiments on grains falling through water. The grains were all very small, none being larger than 0.08". They were allowed to fall through 8 feet of water. Richards found that for quartz grains the velocity was ' Mining and Scientific Press. 2 Trans. Am. Inst. Min. Eng., A^ol. XXIV, p. 409. DRILLING ON LAND 25 According to Rittinger, with quartz having a specific gravity of 2.64, the velocity would be Since civil engineers and contractors rarely have to excavate rock much heavier than quartz, it will be safe to use Richards' formula, In order to lift grains of rock vertically by means of an upward rising current of water, the vertical velocity of the water must exceed the velocity that those grains would attain when falling through still water. This is clearly the fundamental prin- ciple to be used in calculating the quantity of water required to keep a drill hole free of sludge by means of a water jet. Let A be the area in square inches of the drill hole not occupied by the steel at its mouth, then, , TZD^ Tip A= — , (i) 4 4 ^ ^ when Z = diameter of drill steel, D being the diameter of the hole in inches. Let Q be the number of gallons of water per minute rising through the drill hole, as delivered by the water jet; then ^ ,. *^^ 2 = 6°^' (^) v being the velocity of the rising current of water in inches per second. There are 231 cu.ins. per gallon, hence the 231 in the denominator. The 60 in the numerator is introduced to reduce a velocity {v) of inches per second to inches per minute. Substituting for A its value given in Eq. (i) we have 26 ROCK DRILLIiVG Now, according to Richards' formula for the velocity of grains falling through still water, we have v = ^o\^. (4) If the V in Eq. (3) is equal to the v in Eq. (4), we shall have barely enough water rising through the drill hole to elevate grains of sludge having a diameter d. Hence^ combining Eqs. (3) and (4) , we have 231 '^ 4 231 ^ (S) Substituting for t: its value 3.14, we have Q = 6.i{D^-P)vd. (6) In order to provide a small factor of safety that will insure the delivery of the grains of sludge at the mouth of the drill hole, let us substitute 7 for the 6.1 in Eq. (6). Then we have Q = j(D^-P)xd, (7) where (2 = gallons of water per minute; !) = diameter of mouth of drill hole in inches; tZ = dia]neter of largest grain of sludge in inches; ^ = diameter of drill steel in inches. In very tough rock the grains of sludge are often exceedingly small. Assuming that the largest grains to be elevated by the water jet are one-hundredth of an inch in diameter, that the hole is 22" in diameter, and the steel |" in diameter, and applying Eq. (7), we have (2 <^ — o 87^2) Q = jX ^-^ '—L^-^ =3.84 gallons per minute. Should the specific gravity of the rock be greater than 2.6, our formula, Eq. (7), must be modified in accordance with Rittinger's formula for grains falling in water, above given. Now that an accurate method of forecasting the amount of water for removing sludge and rock chips is available, there DRILLING ON LAND 27 should be a much more frequent use of the water jet in the future than in the past. By drying the sludge and screening it the diameter of the largest grain to be lifted by the current of water is readily ascer- tained. It will be found, however, that upon the introduction of a water jet grains of larger size than were previously found in the sludge v.'ill be removed. This in itself is one of the strongest reasons why the water jet increases the efficiency of a drillj for the drill bit is relieved of the work of pulverizing every chip of rock that it loosens. We have plotted these formulas in the accompanying diagram (p. 28) entitled " Chart showing the quantity of water in gallons per minute required to remove particles of sludge from drill holes." To use this chart, obtain the squares of the diameters of the hole of the drill steel and of the grains of sludge. Thus if the diameter of the hole at the top is 3", that of the drill steel f" and of the sludge -^/^ the expression D^ — P = g sq.ins.— 0.56 sq.in.=8.44 sq.ms. This is so nearly 9 sq.ins. that on the diagram we can use the line representing 9 sq.ins. which cuts the vertical line for a diameter of grain equivalent to a -^q-'' at the point corresponding to 14. 1 gallons per minute. The theoretical amount of water necessary, then, is a little less than 14 gallons per minute. In practice, when working in the hole the portion of the bit at the point of the drill is in a very much more confined space than that above. In addition to this the drill is chm-n- ing the water at the bottom of the hole tremendously, so that large particles will be caused to float in the hole above the bottom but will not be lifted out by the upward current of water. It thus happens that upon stopping the drill to change bits it is advisable to put an extra jet into the hole while the helper is cranking up, in order to wash out as many of the large particles as possible. At the best, with an ordinary jet there will be a considerable number of grains, varying from ^" up in the very soft rocks, which settle down into the holes after the bit has been withdrawn, to a depth of one or two ROCK DRILLING inches. These cannot easily be removed by the pump. When the following bit is dropped into the hole, if it does not descend sufficiently to admit of the drill chuck passing over the shank, 20 15 ^10 0.05" Diam. of Grains Q.IQ" 0.15" 0.20 " 0.2.5" 0.05" 0.10" 0.15" Diameter of Grains Fig. I. 0.20" 0.25" 0.30" / / '^ / / r^ j / / - ^ / / ^1 1 / / .^ / ^ c: / / y n 1 / / / X JO 1 c- / /' y .,'l/ .^^ ^. /' y I-' - f' ^1 7 V ^ .-/V 1 / K Qi X 1 \' / f u y 1 ^y / .o'> ^ / ,>^^ / ■^.V\ t^ •" 1 ^ -^ r> / / / / ^ / / 1 / •7 ^ ^* / / / ^ ^ / / e% / / i-- ^> / / / / / D = diani.of hole 1= '^ *k steel" d- " "particle / / ^ U- / / /• f 1 / y y 1 / / 1 ^- i / v ^Vjf "1" V;X — - ^ 1 / / v ,i'' ! J / / / ^ r^ '/ / / / ^ .-' // / / .^ jj / II / ^ ^' CHAKT. Showing Quantity of Water in Gallons per Min. Required to I^emove Particles of Sludge from Drill Hole. 1/ / X 1 / 1 ^ ]/ 1 1 1 1 1 1 1 1 1 1 III 1 M 1 1 1 0.30" it can be immediately caused to settle down by pushing one of the jet pipes into the hole. As soon as the jet is within a few inches of the bottom it stirs up the small particles of broken DRILLING ON LAND 29 stone and the bit then descends by its own weight. It takes about one minute to teach the ordinary drill runner this trick, but usually they will discover it themselves in the first few minutes of work if they have not been instructed. The first thing that the fresh bit does after getting to work is to break -up these pieces which the jet will then take out of the hole. It should be noted that when operated in this manner there is practically no pumping to be done, and thus the time of changing bits can be materially reduced. Attention has been called to the use of hollow drill steel and a special arrangement for jetting water into the hole through the bit; if this equipment be not at hand, we have found that the best arrangement is to use a half-inch hose as long as may be necessary, with a 30'' length of f" iron pipe inserted about 3'' in the end of the hose. When a small hole is drilled it is sometimes advisable to have the blacksmith taper the f pipe slightly, but when the smallest bit has a diameter of 2|'' this is not necessary. To fasten the pipe into the hose it is only necessary to pull the rubber over the end of the pipe for about 3". When in the drill hole, if the pipe is pulled, the rubber contracts around the end of the pipe, thus holding it very firmly. The weight of the pipe keeps the hose down in the hole and by reducing the diameter of the stream gives an extra speed to the water where speed will do the most good. The working of the bit, when the X bit is used, as it should be, keeps the end of the pipe from descending lower than about 6" above the bottom of the hole. It is often difficult to get sufiicient head of water to work such a jet to the best advantage, excepting in hard rocks, unless a force pump be used. We have used a small Deane Duplex pump with 2 1X4" cylinders, running at 90 revolutions per minute and operating six jets. At this speed each jet threw about 6 gallons per minute with pressure of about 100 lbs. per sq.in. through a 50-foot length of the half-inch hose, which was coupled to a "manifold," taking water from a i" discharge pipe from the pump. When the pump was operated at a higher 30 ROCK DRILLING speed than this it was found that the hose had a tendency to twist and squirm, so that with this arrangement 6 gallons of water per minute is about the limit for one jet. For grains of rock with a diameter of yV" reference to the diagram shows that the expression D'^ — P must be about 3 sq.ins. for one jet or about 6 sq.ins. for two jets. The use of this arrange- ment is not practical in holes of so small an area, con- sequently the larger grains will never entirely be removed from the hole by the jet, according to our experience in practice. Where a 3" bit and two jets are used, the largest average diameter of a piece that will come out of the top of the hole is about -^.^ The facts above enumerated explain why the use of a water jet has been condemned in the soft rocks by many so-called "practical men." They have from time to time experimented, in a half-hearted sort of way and with an insufficient head of water, and therefore the amount of the large grains that would not come out has often been enough to clog the bit. For the benefit of future experimenters we wish to say that we have always known the jet to work admirably even in the very softest rocks, when as much as 6 gallons per minute was forced through each jet pipe. In very cold weather these small pipes are likely to freeze, and it takes at least half the time of one man to care for the pump and keep a half-dozen jets going. In moderate weather a small pump of this type can be placed upon the boiler that furnishes the drills with steam and when oiled twice a day will run almost without attention. It should be noted that 6 gallons per minute for each six jets amounts to over 2000 gallons of water per hour, which in dry weather might be a hea"vy strain on the water supply. This, however, will carry away about 10% of its volume of sludge. Where it is desirable to pump the hole out clean, it is well to stop the bit in the soft rocks when the drill has about 5''' more to cut; thus, there will be sufficient thick sludge in the hole to make pumping feasible. One of the standard sets of instructions for this work is here given : Rules for Drill Jets. "In shaley rock of rather soft quality DRILLING ON LAND 31 in which under the jet a 3J" drill will drive a 3" bit \2" per minute. '^ These rules apply to the use of a jet in which the nozzle has a diameter of |" and the water pressure is 100 lbs. per sq.in. '^ As soon as the drill is set up and the first bit placed, get ready with the jet, start the drill and direct the jet into the hole under the bit as soon as it has cut about \" . From this time on keep the jet in the hole with the nozzle of the pipe as near as possi- ble to the working end of the bit. "Let the nozzle follow the bit down into the hole until you see by the drill stem that the drill has about 5" more to go before finishing the cut. Then immediately withdraw the jet and allow the bit to finish this cut. You will have plenty of time after taking out the jet to handle the throttle and wrench. By taking out the jet before the cut is finished there is left enough sludge in the hole to make it very easy to pump the hole clean. *'When the hole has been cleaned, which should be done thoroughly, put in the next bit and start the drill slowly. As soon as the drill has made about five strokes, put the jet in again and keep it there imtil you are within 5" of the finish of that cut, and continue in the same way with the succeeding bits. See to it that the jet follows the bit down into the hole and once or twice for every cut raise it about 2' and push it down again." The cost of operating jets is approximately as follows: CENTS. I pump at $40.00, interest, depreciation, and repairs, say, 50% 13.33 300' half-inch hose, at 10 cts, interest, depreciation ,and repairs, say, 200% 40. 00 Fittings, etc 5 . 00 Coal 17-5° Pipe fitter \ day, 38^ cts 38.50 Incidentals 10. 00 Total per working day for 6 drills 124. 00 Under normal conditions these jets will increase the output from 30 to 100%, to say nothing of the collateral advantages gained by the use of a smaller main plant. The use of such a method as this, which we have here described at some length, 32 ROCK DRILLING sometimes makes the difference between a handsome profit and a sickening loss on a contract. Irregularities in the Rock. The greatest trouble from variable rock occurs in the faulty shales and in schists, such as those on Manhattan Island. For the medium soft rocks a rather thin edge to the drill bit is preferable; while in the very hard rocks in which this thin edge would be broken the point of the bit must be at an obtuse angle. It follows therefore that points suitable for soft rock are not suitable for hard material, and when a bit that has been working for a long time in a soft rock strikes a layer of quartz or exceedingly indurated shale, so hard as to be practically a trap, the point will either be broken or so blunted as to go out of business. It is a familiar fact of practice that a blacksmith who can make either of the two kinds of bits almost perfectly, deteriorates in his work as soon as he has to make both kinds in one day. As soon as he has to change his temper he commences to vary it. This is one reason why the cost of drilling in a mixed quality of rock is generally rather higher than the cost of drilling in any one kind alone. Where the rock is pitched, there is always a tendency for the bit to work out of line in the hole and then stick. This should be carefully watched. Little pieces of cast iron will frequently help the bit past a bad spot of this kind without "drifting." The Use of Steam or Air. Aside from the cost of fuel the arrangement of the drills, whether by steam or air, has a good deal to do with the economy of operation. In mine work, of course, steam is not practicable, so that the following refers to open cut operations. In the first place, the ordinary hose will last a good deal longer with air than when steam is used; then again, the steam from all leaking joints and from the drills themselves obscures the drills and makes it difficult for the men to work and for the foreman to direct them. A compensating advantage in the use of steam is that every leak is at once noticeable. The heat from the steam is so great as to cause expansion in the drill cylinder, and this often results in broken castings. When turning on the steam at first, a jet of hot water comes out of the exhaust, DRILLING ON LAND 33 C/2 which keeps the men dodging a good deal in confined work. Air at 60 lbs. pressure will pass through the ports with less friction than the same amount of steam, and becuase of this fact at least one authority has been in the habit of estimat- ing that at the same pressure about 10% less in actual cubic feet of steam than air will be consumed by the same drill. Conversely, in order to get the standard number of strokes per minute it requires about 10% more pressure on a steam line than where air power is used. There is a rapid radiation of heat, and a corresponding amount of condensation in a steam line, amounting to about 750 pound-degrees per sq.ft. of pipe surface per hour in still air, and about 30% more than this in a strong wind. With an air line there is no such loss as this, and for long transmissions a steam line is at a great disadvantage unless it is heavily lagged. Inasmuch as the radiation of heat is pro- portional to the area of the pipe surface and the carrying capacity of the pipe is proportional to the area of the pipe sec- tion, the larger the diameter of the steam pipe line the less will be the proportionate amount of lost energy from this cause. When compressed air is used there is frequently a choice as to what kind of power may be used to compress the air, whether a steam engine, a gas engine, or an electric motor. o 34 ROCK DRILLING Electric power is economical in a number of instances. It has the following advantages over steam and gasoline: 1. Cleanliness, which is more of a luxury than an economic advantage. 2. Convenience for operating purposes, in that no skilled labor is required to turn the switches on or off. 3. No large amount of housing is necessary. 4. No cost at all for transportation of fuel and supplies, and a very small cost for transportation of plant. Among the disadvantages are the following: a. Susceptibility to interruption from storms. b. The motors must be wound to suit the current available. c. Transmission line must be provided. d. A spark or lightning arrester must be provided. e. In case of the burning out of an armature, getting another machine on the ground is a slow business. /. Where much exposed to the elements the deterioration of the motor is considerable. h. It requires an electrician to operate and care for the plant. Pressure in the Boiler or Air Chamber. In a paper entitled *^ Stope Drills," which we have elsewhere quoted, in the case of eight drills the depth of drilling per minute of actual running at 50 lbs. per sq.in. pressure varied from .93" as a minimum to 1.83" as a maximum, with an average of 1.343", while with 60 lbs. pressure the same drills drilled per minute of actual running time from 1.06" as a minimum to 2.22" as a maximum, with an average of 1.^^^". The increase of pressure from 50 to 60 lbs. is 20%. The increase in performance due to this increase in pressure is over 20%. This solitary fact should be enough to convince any one of the tremendous economic advantage of having all drills work at the highest practical pressure, and further, that is it absolutely essential to have the transmission lines so arranged that the available pressure will be freely supplied to the drill. The Diameter of the Pipe Connection. The main fact to be borne in mind is that the area, and approximate carrying DRILLING ON LAND 3.") capacity, varies as the square of the diameter. Therefore a 3-inch main supply pipe will furnish all the steam that eight or nine i-inch distributing pipes can take. Length of the Pipe Connection. From Kent's '^ Hand- book" it appears that the loss in efficiency at 80 lbs. pressure for pipe lines varying from i'' to 14" in diameter, and up to a length of 5000 ft., carrying air, is seldom more than 10%; so that for air transmission this is an almost negligible factor. With steam lines the loss, as has been stated above, is approximately 750 pound-degrees per sq.ft. of pipe surface per hour. This was figured upon an assumed difference of temperature between the steam and the outside air of 250° F., and the outside surface of the pipe is the one to be taken in the calculations. The following table gives the number of square feet of external area for 100 lineal feet of pipe: Nominal Inside Diameter, Inches. Square Feet of Outside Surface of 100 Lineal Feet of Pipe. Nominal Inside Diameter, Inches. Square Feet of Outside Surface of TOO Lineal Feet of Pipe. Nominal Inside Diameter, Inches, Square Feet of Outside Surface of TOO Lineal Feet of Pipe. f I 2 22. 2 27-5 54-4 43-5 62.1 2^ 3 3l 4 4i 5 75-2 91.7 104.7 117. 8 130.7 159.0 ■ 6 7 8 9 10 173-3 198.0 225. 2 250.0 281,7 At 60 lbs. pressure one pound of steam contains about 1175 pound-degrees of energy when evaporated from water at 22° F. Number of Drills going at once and Drawing Pressure from Same Reservoir. The amount of power that it takes to run a battery of drills is not directly proportional to the number of drills operated. The boiler or air reservoir supplying pressure to a single drill must be able to furnish as much power as a drill would take if it were operating continuously, and therefore there will be a large excess of power, some of which must be wasted when the drill is quiescent. As the number of drills in the battery increases, the drills which are operating tend to balance the discrepancies in power due to the interruptions, and there- 36 ROCK DRILLING fore the available margin of power may be less. The quan- titative expression of this rule, obtained largely from the data in manufacturers' catalogues, is to be found in the diagram which accompanies the section of chapter III, entitled Cost of Power. Diameter of the Drill Cylinder. With the same length of cylinder the force of the blow struck by the drill will vary approximately as the square of the diameter of the cylinder, and the selection of the economic size of drill depends upon the character of the rock that it is expected to work in. A 3 J" drill, which is the size in most general use in South Africa, will deal a sufficiently powerful blow to satisfactorily attack the harder rocks up to and including the granites. For the toughest trap a 2,y drill, which with tripod weighs nearly 175 pounds more than the next smaller size, may be preferable. In the soft rocks, such as the shales, the heavy drills are at a great disadvantage, since the force of the blow which is struck is so great as to drive the bit a comparatively long distance into the rock with each stroke, loosening very large pieces that have to be pulverized by subsequent blows at a great waste of power. For this reason, if for no other, even where comparatively large holes have to be drilled, the light drills from the 2f size down are most suitable for the soft rocks. Stroke of the Piston. Every manu- facturer has a standard length of stroke for each diameter of cylinder and each type of machine. This general fact is to be con- sidered, viz., that, other conditions being equal, the longer the stroke the harder the blow. The following equations explain how the length of drill stroke affects the economy of drilling in the rocks of various degrees of hardness and tough- ness, and the effect on the drill steel. The illustration (Fig. 3) indicates the drill cylinder and bit. fy D > U j Fig. 3. DRILLING ON LAND 37 Let P = steam or air pressure in lbs. per sq.in. free at drill; ^=net area of piston in sq.ins.; / = length of stroke in ins.; m =niass of all moving parts; ?^ = number of strokes per minute; ■u^ velocity of moving parts at any given time; / = commencement of stroke. Assume free passage of steam or air through parts, and assume cut off at 80% of stroke. The resultant decrease in effective pressure is negligible, when the drill is working vertically. /= acceleration of the moving parts due to pressure; ^ = acceleration of the moving parts due to gravity; = 32 ft/sec- £ = total energy of moving parts = J m-z^^^ . . . (i) V^^=2l{f+g). . . (2) by the familiar formula for motion in a straight line. Also, total pressure = impelling force ^32 AP (since P was in pounds) = mf. 32.4P f- V-^ = 21 m 32AP m K~^^S (3) and E==l{s2AP+mg) ... . (4) From these Eqs. (3) and (4) it appears that the velocity of impact is proportional to the square root of the length of the stroke, and the energy of impact is directly proportional to the stroke. When the drill is working in a horizontal hole, the acceleration of gravity disappears, and we have o 32AP and E = 32lAP (6) 38 ROCK DRILLING If we assume for a 3" drill that Z = 6" = Jft. and m = 6o lbs., and P = 6o lbs. per sq.in, then A = j.i sq.in. the value of Eq. (6) is — Xv. 1X60 = 6820 2 ' and that of Eq. (4) is = 7780, a difference of 14% in striking energy in favor of the vertical holes, regardless of the sludging conditions. The Convenience of the Arrangement for changing Bits on each Machine. In the United States the standard method for fastening bits in the chuck is by means of a U bolt with two nuts. It has been our experience that square nuts for this pur- pose are more satisfactory than the hexagonal ones, which are likely to slip in the wrench and require more time to tighten up, whereas the square nut can be drawn sufficiently tight in all posi- tions to hold the bit. The Weight of the Drill itself. This factor has a much larger influence upon the cost of drilling in the soft rocks with short holes than in the hard rocks with long holes, because in the former case the time of moving and setting up a drill is a very much larger percentage of the total working time than in the latter. There are three standard mountings, namely, 1. Tripod. 2. Quarry bar. 3. Shaft bar. Depth of Hole. Usually the depth of the holes is fixed by the exigencies of the blasting, or by the necessities of the loading organization. A steam shovel cannot easily take out a bench of more than nine to twelve feet in heigh, when loading upon cars running on the level of the unexcavated rock. Therefore, when the work is of a character necessitating this DRILLING ON LAND 39 arrangement^ the advantages from the use of very deep holes are not admissable. As the bit works in the hole there is a considerable amount of friction under the bit and around the sides of the hole, with the result that after cutting about two feet in the rock the diameter of the bit is somewhat less than at its start; therefore it has been the rule to make the diameter of each bit |-" less than that of the preceding one. Thus, with ID-foot holes with a 24-inch "feed," if the diameter of the first bit is 3", the diameter of the last bit would be 2^ Now the minimum diameter of the last bit is limited by the size of stick of explosive that must be inserted in the hole^ and therefore the deeper the hole the larger the average diameter. The following is a table giving the weight in lbs. of octagonal drill steel for different lenojths: Depth in 1" r- T" li" ir If- ir If- if" Feet. 2 3.22 4.32 5-58 7.16 8.78 10.74 12.68 14.80 17.30 4 6.44 8.64 II. 16 14.32 17-56 21.48 25-36 29.60 34.60 6 9.66 12.96 16.74 21.48 26.34 32.22 38.04 44-40 51-90 8 12.88 17.28 22.32 28.64 35-12 42.96 50.72 59.20 69. 20 10 16. 10 21.60 27.90 35-80 43-9° 53-7° 63.40 74.00 86.50 12 19.32 25.92 33-48 42.96 52.68 64.44 76.08 88.80 103.80 14 22.54 30.24 39.06 50. 12 61.46 75-^8 88.76 103. 60 121. 10 16 25.76 34.56 44-64 57.28 70. 24 85.92 101.44 118. 40 138.40 18 28.98 38.88 50. 22 64.44 79-02 96.66 114. 14 133.20 155-70 20 32.30 43.20 55-80 71. 60 87.80 107. 40 126.82 148.00 173.00 22 35-42 47-32 61.38 78.76 96.58 118. 14 139-50 162.80 190.30 24 38.64 51-64 66.96 85.92 105.36 12S.88 152.18 177-60 207.60 Note. 490 lbs. per cubic foot used as the weight for steel. Where the moving parts of the "Baby'' Ingersoll 2^" drill (A-86) according to the makers weigh about 20 lbs., with f steel at a depth of 4' the total moving weight is about 28.6 lbs., while at a depth of 12' the total moving weight would be about 46 lbs. The deeper the hole, the longer and harder the pumping process where no jet is used. The deeper the hole, the fewer the set-ups, thus tending to the partial elimination of that large element in the cost of drilling. Note that this is much more 40 ROCK DRILLING important where set-ups are difficult than when drills are moving along a practically level bench. Diameter of Holes. The diameter of drill holes is an elastic factor that can be varied to suit the conditions. A very careful series of experiments on drilling was conducted under the auspices of the Transvaal Institute of Mechanical Engineers in December, 1907, and published in the paper entitled "Stope Drills" written by Prof. J. Orr of that Institute. We have abstracted from this paper data, from which it would seem that the product of the area of the hole multiplied by the cutting speed is not far from constant for the ''Baby" IngersoU Drill with 50 lbs. of steam. This amount was 2.95 for the \\" bit, 2.96 for the if" bit, 2.97 for the ij" bit, and 2.74 for the i|" bit. At 60 lbs. the figure was practically constant for the first two sizes of bit and decreased rather rapidly down to the i|". In the case of the hammer type of drill the rule does not hold so nearly true, the product of the area and rate in the case of the i^" bit being but little over 78% of that for the ij" bit. WTien it is realized that the drill of the hammer type is at an increasing disadvantage, as the diameter of hole grows less on account of possible clogging of the bit, the steel so nearly filling the hole, the discrepancy does not seem so marked, and it will be noticed that the departure from this assumed rule seems very much greater with the smallest sizes of bits. Given a uniform rock and properly designed tools and machinery, it seems a reasonable assumption that with a constant air or steam pressure the performance per cubic inch of material drilled per unit of working time should be substantially constant. Precise experimental data, sufficient to include all the standard sizes of bits, are lacking; and it does not seem likely that the deficiency will be supplied in the near future. To-day the evidence is in favor of the proposition that the actual cutting speed is in- versely proportional to the area of the hole, other things being equal. The economic rule, therefore, in choosing the drilling equip- ment and tools, is to use the minimum diameter of hole in which the drill will freely work when the holes can be sprung, and as DRILLING ON LAND 41 large a hole as can be conveniently drilled when the holes cannot be sprung, except where the rock must be broken out in blocks with a minimum of waste. Rate of Decrease in the Diameter of Successive Bits. In fast-drilling rocks, there is no great wear to the bits and there is no reason why there should -J-" difference in their successive diameters. Therefore with the same diameter at the bottom of the hole it is sometimes feasible, by instructions to the black- smith, to reduce the diameter at the top of the hole considerably and thus increase the average cutting speed. The Shape of the Bit. This has much to do with satis- factory progress. The following article, "Rock Drill Bits," by Mr. T. H. Proske, which we consider the best by far on this subject that has as yet appeared, has been abstracted from the "Mining and Scientific Press." "The success of almost every drilling operation depends on selection and treatment of the bits. Too much attention cannot be given this important part of the work. If the bits have been properly formed, sharpened, and tempered for the work, and if they are changed just as soon as their edges and gauges are worn, the result will be found to be most economical. The power-drill sharpener has removed many of the shortcomings attendant upon the hand-sharpening process, with the result that where these machines are used it is possible to accomplish from 25 to 100% more drilling than under the old methods. The reasons for this are that the power sharpener turns out a much better bit. The saving in the blacksmith's wages should be a secondary consideration. The superior quality of the bits made in a machine will increase the capacity of the drilling machines sufficient to pay handsome dividends on the cost of the power sharpener. ' ' For the guidance of those unfamiliar with the forms of drill- bits used in the different sections, I have prepared a few drawings of those in use. Fig. 4 represents the square cross-bit adopted as the standard for American mining practice. It is made from either round, octagon, or cruciform steel. In the copper mines of Michigan it is usually made of a round steel. In the iron mines 42 ROCK DRILLING of Michigan and Minnesota and wherever this form of bit is used east of the Rocky Mountains, octagon steel is preferred, but in the Rocky Mountain and Pacific States cruciform steel is used. The reason for the adoption of this form of bit as a standard will be appreciated when the three requirements of a rock-drill bit are recalled. These are ' to chisel out a hole in the rock/ ' to keep this hole round and free from rifles/ and ' to mud freely.' There is really a fourth requirement, which is ' to do as much drilling as possible before being resharpened.' " The different kinds of rock to be drilled affect the wear of the bit. Very hard rock will blunt the chisel and reaming edges. The softer rocks do not blunt these edges, but wear the outer sides so that it loses its gauge and size, still appearing to be quite sharp. For this reason a bit that is made with a square edge and a clearance angle of S° will drill about four times as long in soft rock as a bit with round edges and a clearance angle of i6°, before being reduced to the size of the next bit that is to follow. Referring to Fig. 4 and Fig. 5, the latter being a round-edge bit with a clearance angle of 16°, it will be seen that in Fig. 4 the corners of the bit at the base of the bevel describe a circle that is equal to the circle that the chisel edges describe. This is as it should be, as it is impossible for the chisel edge to cut out all of the rock. *'The reaming edge, which is that part of the bit extending from the chisel edge to the base of the bevel, marked *a' in both Fig. 4 and Fig. 5, must ream the outer edge of the hole and keep it round and free from rifles. In Fig. 5 it will be noted that the circle described by the corners of the bit at the base of the bevel is much smaller than the circle described by the chisel edges. This causes an excess of wear on the corners of the chisel edges, the bit rapidly loses its gauge, as well as its efficiency, and it is almost im.possible to keep the hole round. Rifles form, and these cause the rotation parts of the drilling machine to break, often resulting in the loss of the hole. '* The angle of the bevel of the face of the bit has to do with its life as well as with the property of ' mudding ' freely. It is generally accepted that if this angle be 90° it gives strength and DRILLING ON LAND 43 permits the bit to ' mud ' or throw back the cuttings from the face of the bit when the drill is pointed downward. Bits made like Fig. 22 and Fig. 23 will not ' mud ' freely. Another reason Fig. 4. Fig, 9. Fig. 5. Fig. 6. Fig. 7. Fig. 8. ■- I '^ / \ \ \ ^L. Fig, 10. Fig. II. Fig. 12. Fig. 13. why bits such as is shown in Fig. 4 are preferable to those illustrated by Fig. 5, is that having a long wing they are stronger and will not break so readily as does a short bit. 44 ROCK DRILLING "The Simmons bit. used at the Champion mine at Beacon^ Mich., is shown in Fig. 6. In it two of the wings are devoted entirely to reaming and keeping the hole round and free from rifies. Some tests made several years ago in jasper, the hardest rock found in the Champion mine, using a 2f in. Rand drill with 6o-lb. air pressure at the compressor, showed an average speed per minute of 0.28 in. for the ordinary cross-bit, and 0.659 ^' ^^^ the Simmons bit. Both forms were hand-sharpened. *'The Brunton bit, the invention of the well known mining engineer, D. W. Brunton, is extensively used in Idaho and Mon- tana. It is shown in Fig .7. The object of this bit is to obtain the advantages of the X-bit without the attendant difficulties of resharpening. With this bit, as in the case of the X-bit, the piston must revolve a half turn before the cutting edges will strike in the same place a second time. It is as easily resharpened as the regular square cross-bit. The X-bit itself is shown in Fig. 8. Since the invention of power-drill sharpening machines, this bit is fast disappearing. The reason will be understood when a comparison is made with the regular square cross-bit, as made with the power-sharpener, and the cross-bits as they are re- sharpened by hand, shown in Fig. 21, Fig. 22, and Fig. 23. The X-bit is designed to prevent rifies. This the hand-sharpened cross-bit would not do, but the machine-sharpened cross-bit efiectually accomplishes. Fig. 9 shows what is commonly termed the high-centre bit. This was for many years accepted as the proper form. It is still used in the mines of Cornwall and where Cornish customs prevail. Since the introduction of hammer-drills this bit is again finding favor. It is of especial advantage in starting a hole, the high centre immediately making an impression on the rock, whereas the square-faced bit requires a flat face for ready starting. For a starting bit in hammer machines it has no equal. Here, however, its advantages over the square bit end. Used as a bit to follow the starter, it is liable to follow slips and seams in the rock, causing crooked holes, which are sometimes lost before being finished. This the square bit will not do. Fig. 10 shows a bit where the corners are in advance of the centre. This is a fast cutting bit. The corners break up DRILLING ON LAND 45 the rock in advance of the centre and leave httle for the centre to do; this causes the corners to wear fast, but still not to excess when it is considered that they do most of the work. This drill will not follow slips and seams, will drill a round hole, and is easy Fig. 14. Fig. Fig. 16. Fig. 17. Fig. 18. on the drilling machine. The weak point of this form is that the leverage is so great on the corners that they are liable to break off if tempered too hard. Fig. 11 shows the round-edge bit, which is' a favorite with some. In soft rock this is good, but in hard rock Fig. ig. Fig. 20. Fig. 21. Fig. 22. Fig. 23. it permits rifles to form in the hole because there are no reaming edges. '' The Y-bit shown in Fig. 12 gives the advantage of plenty of, room for the cuttings to escape. It is however, quite difficult to 46 ROCK DRILLING make and re-sharpen by hand. With the power-sharpener it can be made as easily as any other form. Fig. 13 shows the " bull " bit in use in the lead and zinc mines of the Joplin, Mo., dis- trict, before the introduction of the power-sharpener. The extreme hardness of the limestone and flint in the sheet-ground of that district, caused the ordinary cross-bit as made by hand to wear too fast. This dull bull-bit therefore had to be adopted. Drilling here was not a matter of cutting the rock, but of shatter- ing it by impact. The power-sharpener has changed all this, and the American standard cross-bit as made in these machines is now used. As a result the capacity of the drills has been mate- rially increased. In mines where hand-sharpening is still done the bull-bit is yet in use. Fig. 14 shows the Z-bit used in hand- Fig. 24. Fig. 25. Fig. 26. Fig. 27. Fig. 28. sharpening in the southeast Missouri lead district. This bit is also used quite extensively in Germany. In both places, how- ever, the advantage of the standard square cross-bit as made with the power-sharpener is fast causing it to be displaced. Fig. 15 shows the ^' six- wing rosette " bit as made in the power- sharpener in use at the Penarroya mines of Spain. It is used in hammer drills only. Of all the rosette forms of bits this has been found to be the most satisfactory. Fig. 16 shows the square cross-bits when made up for hammer drills where a hole for the introduction of air or water to remove the cuttings apexes at a point back from the bevel of the bit in one of the recesses between the wings. Fig. 17 shows the same form where the hole ends in the centre of the cross of the cutting edges. This form of bit is extensively used. Its faults are that a core is formed by this DRILLING ON LAND 47 hole; this core fills the hole, and causes a stoppage of air or water. These cores have been known to become as much as 8 in. long, and are quite difficult to remove. To clear them away the core must be burned out by heating the steel the full length of the core in a slow fire; a sometimes slow and tedious process. This dif- ficulty is entirely overcome by the use of the bit shown in Fig. 1 6. The Z-bit, Fig. i8, is extensively used in Germany, In hammer drilling machines, the steel is formed in bars having a Z shape. While I show this bar straight, it is usually twisted to form a spiral. It is an easy matter to form a Z-bit on the end Fig. 29. of such a bar. The results obtained are excellent. Holes to a depth of 16 ft. horizontal have been drilled with this form of steel. The spiral draws out the cuttings much the same as an auger. Fig. 19 to Fig. 23 are given to show the evolution of the cross- bit where hand-sharpening is employed. There are two systems of hand-sharpening. One is known as the set-hammer system. In it the steel is hammered by placing a set-hammer on the bevels and driving the steel back. The results of this method are illus- trated in Fig. 19 to Fig. 22. Fig. 19 shows a bit made by cutting the bevels with a chisel and is as it should be in form. Fig. 20 shows this bit after about the third sharpening. Fig. 21 is the 48 ROCK DRILLING same bit after about the sixth sharpening, and Fig. 22 is the same bit at about the time that the original cross that was formed on the bar of octogan steel has become exhausted. The other system of hand-sharpening is known as the fuller and dollie system. By this system the stock is first drawn sharp at the corners as shown in Fig. 23 with the fuller, after which it should be set back in the centre with the dollie. Unfortunately the man swinging the sledge hammer gets tired before the bit is set back enough, the result is that the bit, partly finished, is left as shown in Fig. 23. It is becaus^e the power-sharpener has the staying power, and because it readily finishes a bit perfectly, that inferior bits like these are not to be found where machine sharp- ening is employed. ''After a bit has been forged, it should be properly tempered as in Fig. 24. Fig. 25 shows the result of the common method of tempering. The centre of the bit is soft, while the corners are hard. When the bit is immersed in the water about an inch the large mass of metal in the centre cools more slowly than the corners since the corners have three sides exposed to the water. Perhaps the centre had not chilled at all when the bit is with- drawn for annealing, and the final result is a soft-centre bit, which will flatten and retard the work of drilling. Fig. 26 and Fig. 27 show the result of trying to temper the bit with the forging heat, by plunging the whole bit into the water as soon as it is sharpened. The line of tension induced by cooling is indicated. At this place the drill will break. Fig. 28 shows the checking caused by first chilling the steel back of the bit and then plunging with the forging heat. " For the purpose of tempering a bit as shown in Fig. 24 a tank should be provided, such as shown in section in Fig. 29. This should be about 12 deep by 12 in. wide, and of sufficient length to accommodate whatever number of drills are to be sharpened in a day with the machine. The water inlet should be at the bot- tom, and the outlet should be placed about f in. above a grate which itself should be about 8 in. above the bottom. This permits the bit to be immersed to a depth of about | in. With a temper- ing tank of this construction the bit can be hardened to any desired DRILLING ON LAND 49 degree. This depends on the temperature of the bit when placed on the grate. It is essential that the drill stand in a vertical position. To lean either way would cause it to harden to a greater depth on one side than on the other, causing a tension that might lead to breaking of the wings. It is best to provide a rail around the tank about the distance required to hold the shortest drill, and to drive pins about 3 in. apart in this rail. By placing the drills between these pegs thay can be kept in a vertical position. When using this tank a small flow sufficient to displace the water heated by the cooling of the bits should be turned on to keep the supply always cool." An unsymmetrical bit, in which the blades do not all strike exactly alike is preferable to the symmetrical kind, especially in the hard rocks, resulting in less sticking. A test ^ in the Champion Mine, Michigan, with a 2|" drill under 60 lbs. of air showed a cutting speed with the Fitch bit 2.35 as great as with the cross bit. Theoretically, the fastest cutting can be done with a chisel bit, but in hard rocks under a powerful drill, the grinding effect upon this bit is so great as to wear it down before the run is finished, and therefore the four-bladed bits have been developed. Again, theoretically in the soft rocks with a comparatively light drill the bull bit should be admirably adapted, and this would be so were it not that it breaks off pieces that are so large, and buries itself so deep in the rock, as to result in an immense amount of sticking. In one case in point a great many thousand dollars were lost because an enterprising friend of the contractor appreciated the theoretical advantages of this bit, but did not realize why it stuck in the hole. In general, with a light machine and in the medium soft rocks and sand stones the bull bit should be tried first. For the hard rocks the blades should have as sharp an edge and as hard a temper as will stand, because in this arrangement the amount of cutting per blow will be the greatest; while in the softer rocks the edges should be blunted so that the drill will break the material up into small pieces ^ Rock Work, p. 26. 50 ROCK DRILLING and cut less at each blow. In shale we have had very good results by giving two of the blades of the X-bit a fiat face of ^ of an inch leaving the other two blades slightly projecting and very sharp. Nature of the Drill Steel. This should be special steel made for this purpose and not tool steel, and should contain from .8% to i% of carbon. Any alloy that will increase the toughness of this type of steel should be worth its weight in gold. It is probable that the use of steel treated with ferro- titanium, which has been found to have an enormous toughening efifect upon the wearing surfaces of rails, will in the near future offer a marked improvement in the drill steels. Skill of the Blacksmith. The blacksmith is usually a privileged person and very few superintendents have the ability or the nerve to instruct him. He is always an interesting char- acter, generally intelligent, rarely well instructed, and invariably obstinate. A good blacksmith has a right to a good helper, to a sufficiently large and convenient shop, good tools, and the very finest materials. To emphasize the importance of having a good blacksmith perhaps it is enough to say that if the efl&ciency of the best blacksmith in the United States could be increased 50% by quadrupling his pay it would be economy to do so on any drilling work. The average blacksmith with a helper can sharpen by hand about 140 bits a day, which ordinarily will supply about six machines in hard rock. An Italian blacksmith with a helper of the same nationality one winter sharpened 441 bits in 25 days or about 18 per day, this being one bit per 9.3 ft. of hole, being all that was necessary to keep 14 drills going in soft shale. With a bit sharpening machine one man can average 50 drills per hour and the bits are harder, denser, and better formed than the hand sharpened ones. The proper tempering of the bits is absolutely essential. On one job that we inspected on which the contractor wanted to know why he was losing money we found that the black- smith heated his drills up to the lowest kind of a low red before quenching. He might as well have tried to harden them with DRILLING ON LAND 51 cigarette ash. A full description of the methods of tempering is given in Gillette's ''Rock Work," page 26. The Blacksmith's CoaL Coal containing much sulphur will result in some of the carbon being burned out of the drill steel, thus lowering the effective hardness, and sometimes even the steel itself may be burned. While a cheap grade of coal may sometimes be economical under boilers which are under- loaded, it is never anything else than the most expensive luxiuy in the blacksmith shop. The Direction of the Hole. Various experiments have been made upon the effect that the direction of the hole has on the cutting speed. Prof. Hofer obtained the following experi- mental results, the time being that for cutting one inch of hole in a conglomerate with a hammer drill. 85° down (nearly vertical) 152 seconds 65° 52" 27° 2° 9° 24° up 241 282 257 345 These results are confirmed by Jarolimel. The use of a water jet in the hole would probably alter them greatly. CHAPTER III DRILLING ON l.XN'D—ContUnied Comparative Costs of Operation by Steam and Com- pressed Air. The two following tables have been prepared to show: I. Typical cost of operation of a six-drill plant by steam from an ordinary contractor's 65 H.P. movable boiler direct, and total cost of operating one drill by steam; 2. Typical cost of operation of a ic-12-drill plant by compressed air, and total cost of operating one drill by air. Of these costs the wages of the drill crew average 40%. It will thus be seen that a trifling increase in the wages of the drill crew is of small moment com- pared with a similar loss in the working time. To pay the men 10% more wages, which makes them feel much better, is only 40% as costly as to allow them to kill 10% of their time, which does not make them feel correspondingly better. TYPICAL COST OF OPERATION OF SIX-DRILL PLANT AND TOTAL COST OF OPERATING ONE DRILL FROM A STEAM BOILER DIRECT. Boiler at $700. 00, 6% depreciation $0. 28 Interest at 6% o. 28 Repairs at 2.00 per month o. 10 Installation at 50. 00 for 150 working clays o. ^1,^ 2^ tons coal at 3. 50 8. 750 Hauling coal team ^ at 3. 39 at 2^ tons per team day 3-39 Handling coal labor ^ at 1.50 i-5o Fireman at 2 . 00 per day 2 . 00 $16,633 Drill at $300. 00, SS^O depreciation per vr o. 667 Interest at 6% o. 120 Repairs at o. 50 per day o. 50 2 pints oil at 0.30 gal O-075 Driller at 2. 50 per day 2.50 Helper at 1.75 " 1.75 § mucker at 1.50 " i . 00 I pipe fitter at 2.00 " °-333 ^ blacksmith at 3.00 " 0.50 1 Higher than average; depends on condition of roads and length of haul. ^7- 445 52 DRILLING ON LAND 53 Boiler cost for one drill, 16.633-T-6 - 2. 772 Total cost of operating one drill ' 10. 217 Total equipment per day $i.453 % of total 14.3 Total supplies per day 1.535.... ^4-9 Total labor per day 7.23 ' " 70.8 100.0% TYPICAL COST OF OPERATION OF 10-12-DRILL COMPRESSOR PLANT AND TOTAL COST OPERATING ONE DRILL WITH COMPRESSED AIR. Compressor, Rand, Class C, 24X30 at $4000.00, dep. 5%, $200 ^ ^-33 Interest at 6% $240 1.60 Repairs at $5 . 00 per month o. 25 3 gallons of oil at o. 30 o, 90 Engineer at 3.00 3- 00 Installation for 150 working days . at 100. 00 o. 666 Two boilers at $700, depreciation, at 6% 0.56 Interest at 6% 0.56 Repairs at $4, 00 per month o. 20 6 tons coal at 3-5° 21,00 Hauling coal, 2 teams at 3 . 39 7-7^ Handling coal, labor at i- 50 3.00 Fireman at 2.00 2.C0 Installation at $100 for 150 work days (BoUers) . . - o. 666 *43-5i2 Drill at $300.00, dep. 33% 0.667 Interest at 6% o, 12 Repairs at 0.50 per day. o. 50 2 pints oil at o. 30 per gal o. 075 Driller at 2.50 2.50 Helper at i . 75 1.75 2/12 pipe fitter at 2.00 °-333 J mucker at i . 50 i . 00 2/12 blacksmith at 3- 00 o.<,o 7-445 Compressor cost for one drill $43. 512-M2 3. 626 Total cost for operating one drill by air S 11. 071 Total equipment per day $1. 773 % cf total 16.0 Total supplies per day 1.90 " " " 17. 2 Totallabor per day.. 7.398 *' " " 66.8 $11,071 The Amount of Mucking Necessary. This will depend largely upon the lay of the ground and the time of the year. It is an absolute rule of economics, geneially violated in practice, 54 ROCK DRILLING never to allow the drill-runner and helper to do the mucking. Where a number of drills were operating in a narrow cut through which water was running and freezing to a depth of from 8'' to 13", where also the rock surface had been badly shattered by previous blasting, requiring an average of not less than 8" of mucking for each drill hole, one mucker at a cost of about 11% of the total cost of the drill operation was enough for each 2.2 '2.0 1.8 l.G 1.4 1.2 1.0 0.8 A" / / m:: I ist on p - n. / / / 60 70 80 !) 100 no li / / 10 \ / m II Factors bj wLicb to multiply for varioQB altiludee > and preasiiree. ^r ^ 8 OO^O'EI 6 000 'E / / /' y / / / y ^ / ^y Tmst\ •2. UUlt'F.l / / / y y A 'A ,^ << ^ / / X ^ / 9" ^^ A ^ ^ ^ ly / / y y ^ ^ v^-^ / / / /' ^ ^ / / v y\ y y m 1, ^^ / / / /' y ^ ^ ^ v / /' ^ L^ ^ — / / ]/ / ' ,^ /" f^ ,-' -^ .til iL Y^ V y ^ ^ ^ ^ -^ i / ^. V y y ^ ^ rr /// / y ^ — -^ DIAGRAM SHOWIf^G Cubic Feet ot Free Air to Kuii From One toForty Rock Drills at 75 lbs per eq. in. press. Compilea from M'f'rs Catalog //// /^^ ////. ^ ^ Vy ^ 1 1 1 M M ■4000 -3000' ■2000 ( 1 lu 20 yo 40 Kuml>er of Drills Fig. 30. drill; and the cost of mucking in general will vary from this to nothing in the case of rock which has been previously stripped of its earth covering. The Cost of Power. From the accompanying diagram (Fig. 30) the number of cubic feet of free air per minute to run from one to forty drills can be read directly. Assume that we are to operate six drills of 3I" size and the average make, at 60 lbs. pressure. From the larger part of the diagram inter- polating between 3" and 3I" drills, the amount of free air required would be 625 cu.ft. per minute at 75 lbs. If the altitude and DRILLING ON LAND 55 pressure were 2000 ft. and 60 lbs. respectively the small diagram gives the factor .9 which, multiplied by 625, gives 562.5 as the cubic feet of air per minute required for these drills. By Table A, we have, under the worst conditions, the necessary H.P. for compression equal to 562. 5X. 1342 = 75. 5 H.P., and under the best conditions 58.5 H.P. This amount must be actually effective in the compressor. The efficiency of the air transmission line will average from 90% to 95%; and for compound engines one Brake LLP. for every 2.2 lbs. of coal burned per hour may be expected. There- fore, for the case under consideration, the coal consumption would be about 1700 lbs. per day for isothermal compression and 1300 lbs. per day for adiabatic compression. To estimate the cost of coal, if a steam boiler is to be used directly, we must proceed as follows: From Table B, at 60 lbs. pressure i lb. of steam equals about 5.7 cu.ft. of free steam or free air obtained by multiplying 28.9 and 0.1968 from the last column in Table A. Therefore, if run from a boiler direct the amount of steam required would be 562.5^28.9 or 19.4 lbs. per minute or 1167 lbs. per hour. One boiler H.P. is the equivalent of 30 lbs. of steam per hour at 70 lbs. pressure, evaporated from water originally at 100° F. and is the equivalent of 33,305 B.T.U's. Since we need 1 167 lbs. per hour, dividing this by 30, we get 38.9 as the theo- retical boiler H.P. that we need. If the boiler efficiency is 60%, a fair aveiage value for an exposed boiler of this size when fairly well cared for, the boiler rating should be 38.9-^.6 or 65 H.P. These figures check with our experience. Now, as to the amount of coal used. From Kent's '^ Hand- book" the heating value of i lb. of coal varies from 10,500 B.T.U. for Kansas bituminous, to 14,200 B.T.U. for the Cumberland semi-bituminous kind. Special ' coals often run above this, but the average that is likely to be obtained in ordinary construc- tion work will not run much over iiooo or 12000. We need 1167 lbs. of steam per hour multiplied by 1176 B.T.U's. from "Table B." This divided by 12000, multiplied by 0.6 and 0.9 equals 56 ROCK DRILLING TABLE A^ Brake (or Delivered) Horse-Power Required to Compress One Cubic Foot of Free Air per Minute to a Given Gauge Pressure. (Haswell) Gauge Pressure, B.H.P. required under the worst pos- B.H.P. required under best possible Volume in Cubic Feet of Air after Com- pression at 60° F. Lbs. per sq.in. sible condition. condition. (With Con- (Without Cooling.)^ stant Temperature.)^ 5° -II95 -0951 .2272 55 .1270 .0994 .2109 6o .134^ .1040 .iq68 65 .1403 .ic8i .1844 70 .1472 .1124 -1735 75 .1537 .1163 .1639 80 -1597 -1193 -1552 85 -1655 .1224 .1474 90 .1710 .1256 .1404 95 .1763 .1289 .1340 100 .1815 .1312 .1281 For the purpose of comparing compressed air with steam, Table B will be found useful. TABLE B 1 Steam Volume and Temperature at Given Pp.essures Gauge Pressure, Temperature, Lb. Degrees from Cu.ft. occupied by Lbs. per sq.in. Fahrenheit. Water at 32°. I Lb. of Steam. 50-3 297.8 I172.8 6.53 55 3 302.7 1174-3 6 09 60 3 307-4 II75-7 5 71 65 3 311.8 I177.0 5 37 70 3 316.0 II78.3 5 07 75 3 320.0 II79.6 4 81 80 3 323-9 1180.7 4 57 85 3 327.6 I181.8 4 36 90 3 33^-'^ I182.Q 4 16 95 3 334-5 I1S4.O 3 98 100 3 337-8 I185.0 3 82 ^ Gillette's Rock Excavation, p. 50. ^ Adiabatic. ' Isothermal. DRILLING ON LAND 57 211 lbs. of coal per hour, being practically equivalent to one ton per day for loo ft. of pipe lead. The factors .9 and .6 represent respectively the efficiency of the pipe line transmission and of the boiler. LOSS OF ENERGY IN STEAM PIPES BY RADIATION IN DELIV- ERING 1,000 LBS. OF STEAM PER HOUR THROUGH A BARE WROUGHT IRON PIPE 100 FT. LONG, TERMINAL GAGE PRES- SURE 75 LBS.' Nominal Inside Pounds of Steam Lost per Hour per loo Linear Feet. Diameter of Pipe in Inches. By Friction. By Radiation. Total. I 177.7 22.9 200. 6 li 58.2 29.0 87.2 i^ 23-4 33-2 56.6 2 5.6 41.4 47.0 ^\ 1.8 50.1 51-9 3 0.7 61. 1 61.8 3h 0-3 69.8 70.1 4 0. 2 78.5 78.7 The formula for this work can be derived as follows: From diagram, Fig. 30, iV = number cubic feet free air per min. for the drills in question at 75 lbs. pressure and at sea level. n = coefficient for altitude and pres- sure. C=B.T.U's. in one pound of coal, say 12,000. S = number cubic feet occupied by one poimd of steam at the given pressure (Table B). V = volume of one cubic foot of free air after compression to the given pressure (Table A). W = number of B.T.U's. in one poimd of steam from water at 32° F., say 1 1 76. E = percentage of boiler efficiency. From small diagram, Fig. 30; From table, page 56, From table, page 56, From table, page 56, ^ Rock Excavation, page 60. 58 ROCK DRILLING From table, page 57, e = percentage of pipe line efficiency. Then Nn = Sictual, cubic feet of free air per minute to run the drills. iVi;w= number of cubic feet of compressed air per minute to run the drills. JSfvn — ^ = number of pounds of compressed steam per minute to run the drills, not allowing for losses in transmission or boiler and 6oNvn , c 1 r —w^ — = number of pounds of steam per hour to run the drills, allowing for losses in boiler anp- steam line. 6oNvnW , r ^ r ^ ii i — P^—^— = number of pounds of coal actually consumed per hour to run the drills from a steam boiler. Time Study and Costs of Drilling with Steam and Air. The following is the analysis of the operation of drilling with a machine. Time to change bits and pump hole =e min. Time to drill one foot =d min. per foot Time to move drill and waste time =/min. Time to set up drill =g min. Length of feed in feet =/ Depth of hole in feet =D Time to drill length of feed =fd Number of bits per hole D 7 D Time to drill one hole =(«+/<^)^ + (^+^) including moving and ■^ setting up drill. Number of working minutes per day = M (say, 600) Number of holes per day Feet drilled per day {e+fd)j+(l+g) DM (e+fd)j + {l+g) DRILLING ON LAND 59 Cost per day =C=on standard basis. Cost per foot drilled = jrr: =-^) - + rf+ l±g\ If l^g = S, or the average time to move drill and set up; df=r, or the time to drill the length of feed; and e + y=Ty or the time required on an average for changing bits, pumping hole, and drilling the length of feed, this formula reduces to the following: CT CS Mf'^AID' These two expressions have been plotted for both steam and air operated drills, in the accompanying diagrams from which can be read directly the cost per foot of hole when these values are known, and the values can be obtained in a very short time in the field with an ordinary watch and note book, within a ver}' small limit of error, so that by means of this diagram it is possible upon field inspection to tell about what the drilling is costing, and, by the application of the data of this volume, what it ought to cost. It should be noted particularly that feed is the difference in length between the successive bits, which for ordinary work is 2'. It makes no difference in this formula whether the machine has a possible feed of 30'' or I2'^ the value is effected by the successive lengths of the bits alone. Where it is difficult to get the following bit down into the hole a machine feed should be used several inches longer than the difference between the lengths of the bits, since this may effect the time of changing bits and pumping the hole. 60 ROCK DRILLING "T ■"" — ~~^" ■ \"r 6 3 a . en Ul + o °^ "^ S g ^ - V ^ -1 . - k 1 \ \ ^> -L 1 "'."1= ft \ L \ r ,g N \ .- --- % \ -^ - - ( ^h- ~ o +^ -3 6 S +^ \ ■ \ J Ll " \ V P _ C ^ L \ o \ \ \ _25 V \ ''^ *' o - j\ - Tl - ^ - 1 ^ \ ^ :i . _ S\ ^ ■ <- V ,.\ \ o ^ ^\ - = = e II II II 11 rs -t ba 'I ■+- t 1 -^ol@^ 5^\ \ ~- ;i^'-'lS TjiN \ L i ". V \ \ ' 5 »5 a^ \ t: ^.\ =: '^ ";?d V "C c^ «^\ \ -a*^ '°it "T"^ V± ^ ?r : c VI=no.of working min.pe p= depth of hole f=lengtho ■ feed in feet Let lfg=S df=r. zo\Q li II C o=?t ^ T V Of STEA per ft. dr t per day i a o - ^^ -f ■> hf ■ =^ >» _S> III It" <^ |C>SJ~ \ ! 1 ■ ^ '^ r ~ V \ ^ I _|^LL=V--'4'-^-rf:SiE:ti ' ?-^ c C Where C=< o ^ 1 \ i \ ' \ S ^^ - v\t\ . _ ^ " sl\ \ 5 o -^_ ii . -XA-\ M g V 4^\V o a 4- " \i rj) O O O N ■ 1 ^ (N Yl 1 ■^ 1 [" 1 ^J s H ?2o°8r^^cSi^ k s -J I-oi^^f5o(^5Q6(M I CC 03 o ' o ^ \l 1 s Q '^ 7A "/JaI s '^I\ V < VI S__l ^^ 1 \ 1 r (3 ^ V. s \ ^ . rH- -! ■-J t^ s s t ^ rt o \ . 9; 00 > . . ^ r- -- -- - ^\ o ^r p5 Pi C3 2:^ ■« 5 ^ s 'y \ \ "tt P o-?, S^§a ^'3 ^^ rr^ \ V ^^«P3C3^cq-^ ^^ I - A \- b^ t: H w [^ ^-« t^^ '^r1 i- ^ N ^S^^M^fcnVi^ ^> r S± Ortp'-'P^^^ QJ^ ^/'s s, . ^ ^ a --: +^ v ^ iK: > t. t- S * S ±S -^ 3 _, ij ^ s K, s--^^-K ^ ^ ^ == S ^ ^ "^; ^^■^ t I it X S o 'S 'S .s* r V ^4*^213 QQ^ ' ^, 1^ *'f \ h j\ \ Ph M l-l MH •V ^ '■^ S s - - s; - -r^ 1 , ^ 'n -tJ^ "*, -■■ '^ \. 1 N. \ N *^s -K J\ ^ -vN ' ^0 >S r- ^. 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' v ' ,- io ^ C3 C;! ^s^ -B^ ^.S l[up aad 3S9DDU iDaiOq JIM XC pjBpuBjs drand pm V ^^^\ v s MV Up 3[0ii JO ij I tiup ^s SSu ic3^S J siiq D3n^qo o j jsoo Tv * ■ ! _L 1 r O) l?n"N -a ^ 00 0) f> w O b e 2 o Q) S m C! o o ',i O t. a a u o II 92 ci c5 >. 4^' I- 3 -J E3 ;::: (D B TJ flC >» ■ to CI) o s ^ Ui o o A-l ;li V d CD J3 13 o o o ■— 1 0) +-> 4-» a CC (U a 4.3 a 3 o «M u a ' n. bl ■E tr _J u 1 c a> 11 1 fl m (H c n 3 T-f =0 f1 T3 II Jl Q Tl r-, ■(J Q ^ u. fl 3 CU 9J O c; CM n >1 1— -M O a ^ a> tn ^ ^ ■M >j -d it O o o O a j3 C3 fi? ti uj ^3 +^ CO oJ rH O (U H^ DRILLING ON LAND 61 r—T — ~ ~ — T " T'Z-T ■"" - 3 ? aj ^ -O '3 Ci ^ 1 r g " s n a b. ^ II 1 ^ 5 s ^ 3 ^ ^ H o 1 4- 11 N t X s ^ I L V \ : \ k i ^ \ _^ - i\ \ "^ L r\_± o N To\ T ' -# ^ J ^, O =1 r s -Vi i L , X r r~ (t T r" =i ^ - > V 1 \ 1 a *^- '- % 1 1 2 - -■■ F It -~ 9 £l (i - 1 \l If 55 2 X n 1 I'r s \ 1! 1 H S & s a -L-t-- ^\ - 1 1 "f ^ _\ J s -^^ L — 1\ J -^ — 1 — ( ^•^^ I -A^r5 :c ip : ^ ^t 5 ir_ 1 -^ 'O*^ ■ f H 1 r o r ^ iV ^ o CO 4- --- w M ^ t l4i. t- - ^ ^Cflf^ t rtOS s ^ - :1: \- \ t >■ 3 1 :5_ jL: \: : a ' s S ' c 2 : -^ 2. rf 3 15 o S o X ' -■ ■ r-i ^ -S t ^ ■■ =5 n u c: r T o 2 h ir" \ ill s ^ ■s m^T s \' - ^ V \ \ H 3 =! >^ X^ \\]\ S ^ T^"- Km "C _l_k 1 (-■ vj ^ M 1 '■>' 1 1 \ I ^ _ J CO o o o o »ri o - § i - u "^ ri -^ 'O^ A .|«ScqM ^.| - d (D ^■■ - CD rH CJ -H ^ V S \ — •v ^ Q jy s. S s -^ s , ''Q^ \ L -H =5 1 1 -- ^A s »*i\. 2 CS -o 3^ J V \ ■z. Q_ V ■^ S 11 r s k h H •^ -in ''^ V \ s "■^ < ■'• * - s T^\^ V [s 's C tJ' s u 1 1 1 ''s cS s; c s ^ ■^..^N^ ^ '4 r^ SI s 1- k ^ s ^ !. C < N V > c V'^ \ *^- > "^r-tN . -^- ^ s y^' . ■^i ''\ ' s > __:^i^__ ■A sJ \ 5 c o - - -^ -fX ■ 1 s A — 1 CO '^ 1 ^i^X / ' I 1 : : : %2 s -P^e^n :s,:: : : 1 ^-t&n^ ^^ / N ^ s 's ^^^ ::5: . ^ s V 1^ ^ > f. > In s " 5 ^ ? 5 k ^v ^ ^, - ;5:_::.^ o 's ^ ^^\ \, ^ (M V«N \ ^ *< 3s^: \. *!. ^, ■c "-s ^. \- s 1 \ s w ^t. \ S N. ■* ^ s s H^ i ^ "^ ' ^ S ' ^ s^ - >■ ^ s Y 1 ^. V o g ^ g g "^ = sjuoxi OT JO ^^p TIPP .lad IZO'XIS JO stST?q pjBpuB js qt{% no aioq jo 'u I IIRP pm3 (^i3SS30on ji)a[0n drandpuB sjtq qSu'bho o^ ':^soo "s: ^i o !l '. 1—1 N 'e \^ - -^s - ^ S^ ^ .\ "^ -^ ^ ; ^ ^ N^^ ^s S' \ *^* S^. ' 5r ____ _ _ __ _ *= b Si S 9 -^ t- a ? I - ^ i a - ^^ faO 3 'S a -o o ^ O. 13 □ a 't-i ,_; o :: r^ (I) bi) n U D o « Z5 o -M -a fO -a (IJ a -«-i c^ o D 2 o fcoO ^ ? ^ -o o O O •^ ?^ rv ft -2 ^ ^ n o g ^ Ll. O o o 62 ROCK DRILLING DIAGRAMS OF CUTTING SPEED IN VARIOUS MATERIALS WITH AND WITHOUT JET 1.150 a. 100 1.150 T" V - . be c 3 .050 .900 MO Moan ._ ^■^^:v^' P ^ .800 .7J0 .700 CJO - SauJ^toue 1 Willi Jet ; TTT .000 .550 .500 .150 .400 .350 -I 1 -3 '"Siiliaijucous"! M -^H-T M^aQ 1 i — >:^ha. M - - \\^iili,!l'e%| i ".. r '■Dry ''/; — ^__l- [^ .L-J.__L_L_L r '2' z ^ ,i ,-'1 - — 1 Ml- in _ 3 .300 ^— -— < _F=^ r- 1 [— fj Lime.itout- M"c'au .250 .200 .150 '!\'r r.T . ;.-... L.I. / 'Witiv .Ta JMt -SMl,;,M,R...i^- MuLiu x-f J-?- i ■M.'au ^ ■■I'l/'. —J Mai.- WitliLiiil Jcl (.ij:iliih- J ,\Vil.buui J^-t ! ^ "'. ? .100 .050 000 "T' 1 ■I'l.', ■■ lI J\Vitljourjet2 WuIjouL-J ; ■; 1 ^ — ■ - — — ' ^ . ■ — -- — -^ ■^ ■^ — — ^ — — . . — —i' 120 120 No. of Observations Material. Jet. No. Obs. Avg. Ft. Min. Authority. Limestone Limestone. Slate Without jet.. . . With jet Without jet Without jet.... Without jet... - With jet Without jet.... Without jet Without jet With jet Without jet... Without jet 152 147 94 120 30 125 45 65 100 100 0.117 O.311 0.144 U.181 0.229 0.956 0.242 0.273 <3-335 0-556 0.104 0.146 Cons. Service Co. Cons. Service Co. Gillette Cons. Service Co., neous (10) Cons. Service (no) H. P. Gillette Cons. Service Co. Miscellaneous Miscellaneous Cons. Service Co. Cons. Service Co. H. P. Gillette H. P. Gillette , H. P. Miscella- Granite Sandstone Sandstone Schist, quartz. . Porphyry Shale Shale Soaps tone Trap DRILLING ON LAND 63 ■7' 00 6' 45 fi' 3o" 6' 15' ^'45' 5' 30 5' li' r>' 00' 4' 15" i' 30 i' 1.5' i' 00 3' d' ^' 30 3^ 15- S' 00 2' 4,3' 2' 30' 2' 1.3 ' CURVES ' ' for use in forroula) (Values of "■ TO SHOW TIME TO CHANGE STEEL-STOP TO START No Pauiping ISecessary Pumping Necessary No.Obs. Mat.Min. Avg. Max. Anth.No.Obs.Mat.Min. Avg.Ma-x H Slate q'v)' SiaC G^j" C.S.Co. 12 L.K. l-'i:^" li)'j"l(i-i5l 8 GraD. \'-li>" 3^^^" o'ly" ■■ I'J Gran. 'I^m' S-iki" B-aSJ 20 " 1-5U" 3.'49" &-'40" " 27 Ciran. 2^2:/ b-'-^" T-^iJUl 1& LS. 1^" *io" 9^30" '■ 13 L.b. i-'io" (^.'.iO"n'u&[ No Pump in Fuuipiut,') 3 Win. 31 Slc. Slate r..s. >I«an_( pii.iii i)i II ^ )J>J^h. " ■ ^ •i'-Sei-j T— j~ rP ump iii M^i^^j^^feiaAg No. Observations Values of l+g = "S" Time to Move and Set up Drill for One Hole JJote ou Column Work Divide tlie tiuie stlected for dismant. liug columu & drill and seltiutj up by no of holes drilled at one settiuy of col, and add to the value chosen Ironi ■"Ooluuiu tiui've" to get proper •'S"= "l+g" to use ill coax CURVES. -Mean -7-1 0' 00 ^£; [C'uluiuui No.Ohs.Avg.Mouut Auth. 2 7-45 Tripod C.S.C0. 2 8-13 2 24-07 " G.Avg. 2&.(K) " Gillette 3 33-23 " C.B.C9. 2 3i-2& '■ i. 2 47-13 " 3 27-37 .. 3 l.UO Golumn Mm. Rep 1 o.iin ™ " ?^ ■' ' Z 8 S-lOJib -S -. 1 9-45=^ « Dismau. &9ettiDg'Up Column&drill ColuLim values* g jo^.^q u C.S.Co. applicable to quarry bar G-Avg. 28-00 » Gillette '^Unosualf long time due to fact that after dismantting coIuiuq and drill had to be taken No. Observations D out of headiDg for blast. 64 ROCK DRILLING Directions for Using Cost Curves I. Estimating the Cost of Drilling on Proposed Work. Let us say that we wish to make an estimate of the cost of driUing under certain special conditions. Drills to be tripod mounted and operated by steam. The rock is solid limestone, holes to be lo ft. deep and pumped after each length of feed is drilled. Feed 24^^ Proceed thus: On the diagram of cutting speeds (p. 62) we see that an average performance for limestone is 0.117 ft. = 1.4" per cutting minute. Time to cut 24'' is then 17 minutes. On the diagram marked "e" Curves, we note that a fair time for pumping and changing steels is 5 minutes. The men to be employed being well trained we will allow 4 minutes for these operations. On the bottom of the same page in the '^/+^ = 5"' Curves, we note that 26 minutes is a fair time to move from one hole to another and set up and get started (for tripod drills). But with experi- enced men and solid material we expect to do this in say 12 minutes. The average time then to pump, change bits and drill the length of the 24" feed will be 4 minutes, plus 17 minutes, or 21 minutes, and on the diagram for steam-operated drills the 2T-minute line intersects the 24'' feed line opposite 18 cts. At the right of the diagram the r2-minute line for moving and setting up drill intersects the lo-foot line for depth of hole opposite the line representing 2 cts. This, added to 18 cts.. will give 20 cts. as the cost of the drilling on the standard basis, including plant, depreciation and repairs, but not including superintendence and overhead charges, the total charge assumed being $10.22 per drill day of ten hours. Where the working time of a shift, or the drill charges per day are essentially different from these assumptions the number 20 should be multiplied by the C expression c.585 jj} where C is the actual cost per drill day and M' is the number of working minutes per shift. The figures, can of course be obtained without the diagram, but it is useful in saving a good deal of time in computation. DRILLING ON LAND 65 2. Checking up the Cost of DriUing on a Job under Way. Material Granite fairly solid. Pump used. Drills Air — Tripod mount. Feed 24 inches Holes 10 feet With ordinary watch take the following observations. Obs. (i). Drilling 24" of hole (start to stop), 16 minutes. Obs. (2). Changing steels and pumping (start to stop), 7 minutes. Obs. (3). Moving drill over to new hole, setting up and getting started, 35 minutes. Add (i) and (2)^16 min. + 7 min. = 23 mins., and with 23 as abscissa, read opposite the 24" feed line on the right side of page on " Cost Curves for Air-operated Drills," 21.3 cts. as the cost of drilling, pumping and changing steels for one foot of hole. With Obs. (3) or 35 minutes as abscissa, read opposite the ID-foot hole line (on left of same sheet) 6.4 cts. as the cost of moving drill over, setting up and getting started for one foot of hole. Then 21.3 cts. +6.4 cts. = 27.7, as the total cost of drilling per lineal foot (supeiintendence and overhead charges not included) on the standard basis of $11.07 P^^ ^^^^^ ^^7 ^^ ^^ hours. Now to find what a fair average cost for this same work ought to be, proceed thus : On the diagram of ''Cutting Speeds" read the mean cutting speed for granite as 0.181' per cutting minute or 12X. 181 = 2. 172'' per minute. Use 2" per minute. Then time to drill length of feed 24'' would be 12 minutes. On the diagram entitled "e Curves" we see that the average time for pumping and chang- ing steels is 5 minutes 13 seconds, say 5 minutes. Using this value and adding to it the 12 minutes we get 17 minutes as a fair average time for cutting 24", pumping and changing steels. On the ''(^-hg) =5 Curves" (p. 63), we see that for tripod drills the average time for moving from one hole to another, setting up and getting started, is 26 minutes 9 seconds, say 26 minutes. We now have the two quantities to use in the '" Cost Curves for Air-operated Drills," namely, 17 and 26. With 77 as abscissa, read opposite the 24-inch feed line on 00 ROCK DRILLING right of '' Cost Curve" sheet, 15.7 cts. as the cost of drilling, pump- ing and changing steel for one foot of hole. With 26 as abscissa on the left of same sheet, read opposite the lo-foot hole line 4.7 cts. as the cost of moving drill over, setting up and getting started per foot of hole. Then 15.7 cts. + 4. 7 cts. = 20.4 cts. as the total cost of drilling one foot (superintendence and overhead changes not m- cluded) on the standard basis of $11.07 P^^ ^^^^ ^^7 ^^ ^o hours. The actual cost was 27.7 cts. per foot, a difference of 7.3 cts. per foot drilled. If a plant of 12 drills did 32' per day the excess cost above the average would be 12X32X7.3 cts. = $28.03 per day — a matter that might well be looked into. " Experience Tables of Cost of Drilling and Blasting and Amount of Explosive," compiled from various sources, are given on pages 67-74. Standard Rates on Dry Drilling. On the various pieces of work described in this volume there has been some difference in the rates of wages, so that the actual costs obtaining on the work are not a true index of the efficiency of the various field methods. To eliminate this discrepancy, and for the further reason that many contractors do not like to have the public informed of just what wages they are paying their men, the wage items have been reduced to a standard basis. Where the data here given are to be used for estimates, it is necessary only to substitute in the cost tables the new rates. TABLE OF STANDARD RATES OF WAGES FOR DRILLING Runner or driller. . . . Runner helper Blacksmith Blacksmith helper . .. Engineer Fireman Pipe fitter Powderman Labor Coal Oil Dynamite Rate per Hour. 2Z, Cts. per hour 30 17I 30 20 20 20 Rate per Day. $2. 50 per day 1.75 3.00 1-75 3,00 2. 00 2.00 2. 00 1.50 3.50 per ton 0.30 per gallon o. 12 per pound DRILLING ON LAND 67 X iT 1—1 c .-] o hJ «) 1— 1 Pi Q 'H In O Q in c H tn ^ C/3 O % u o d M "h W w i-l bo pq c '^ < ^ % - h ^ 5h CI H Ui -^ « ^ 1— ( Pi o ci frl 9J A 3 Ph > ^. c« X CO K W t ,^ O d) in t-i -- p ■ 'd ^ ^ g ^P g '-' u :3 ITT3 I> H O ■Tl 4_, ■ O ^U ■ir; ■ i^ .5 •G ^ ^ ^•^-^ &?ga^ .• u t '5 " - o p (X -1- t: ^ % X. • tn u ^ r^ :^ o " y o ri rt Ln P= P bO i^ (£ CI. 6 1^ d C '^ O g; (/; =i .^ ;3 n tfl o OJ cr X M cr d d d n bO =1 ^ ;3 :3 a* ^ C/J P^ U1 J2 J2 Xi 68 ROCK DRILLING I O 1—1 1-1 c o o P2 2: 1, CO ^1:5 ^ CJ (U "^ 1-1 ■i-' aO ^ ^M^ ^ O P " W fTl Rj ■*-< o d"^ <1) 13 cd si M C-1 OJ s « ?- rt 'i-^ tfi en -.— , — 4-i to , Ih §5 ^ C3 f ) b ^ o ri u >. ^PQ fTl -c: )-i -; CU *- -X m O OJ -t p O-^ Tl n ':i! ij .■!=; rt c W k;; ^ O :n C c/j S CG r '^ s °p ^ J . rt )-( ;? 3 -. N rt _ O rt o O "^ (J O CJ tE £ o Oh cd ^ P3 m 6 2 O r— Lo '^. *"! ri :5^ <-/ CJ o o (U OJ (U r^ 7i , , t: P ;3 :3 ^] ei o ^ C^ CT* c^ 'J^ u" U" n: Ti « rt rt a nJ d TJ _Q Sl in C ^ ^ ^ £^ ^ ^ c =3 P o^ OJ ^ =3 3 dJ ^ W C/2 C/J 0-, o LTj in CO o C/2 CAi )_ 1 ■ui (Du_. rt a abor r Foot Hole, Cents O CO lO ^o fl vO CO M Kl H ^ r^ LO CN -1- u-j CN On , -- . • > • t^ I>- t-* < Q ^ lO O vO VO \o ^O J DRILLING ON LAND 69 ^ K G ffiQC G C O I— ( « O O U O W W o :^ 2 w o o S 2 I- c rt '4:; 0) := jij 5 y -r! ^ ■T^ H (D ^ o H r3 H ^ o P t1 ap; g.H 00 £^ P - (D 0) ■i-J IT c^ fig- .^ o W ^ -^ ■ ^ ^ w .5 rtW X X^ ; :-c, o C 1- < (U a> . g a^ 1 t; t: ti A rt bo-ir; (u *■ QJ OJ OJ < a -u ^ ^ -^ _D JD JD rt O ."T^ .Th ~ 7^ 3 r3 r^ 1 Q ffi CO O o c o til o i X3 "^6 % I D- • cd , — tn C t U -*-> (U • ^ 00 w" ■ Kt C) ri N g bc fi :^d -^ . S c .2 u d ^ ■> •3 00 O d 1- O In U ^S as '- oj tH rt Ci ^ Sj^ ^O Jj^ u 'u a c/3 I— < ^ (=: W OJ 2d| PP ^ C/^ in in m ^•c - -oQ N M 6» CI « « M 1 65 ^ M !=1 . 1 -k - la ^HSt'H* -:1- ^ CO 1 5 , Depth, 1 Hole. < 4 ■— J 1-1 n o . s c -u s s •^ 1? M rt rt d rt ^ S Ifi 1 "S "trt cH •d (U C ui m yj m uj ;3 m 3 o o O O ^ =3 § S M 14-, CT CT* C^ d rt rt x: ^ JD ^ c 3 ^ =3 ^ S ^ 3 3 13 W i ^ ^ C/2 LO CO ^ "^^ n ^ 3 fi 1^ -«— t- -1- O 'O i^ t-i -+ M r^ ^ -Ir! :5 o o o c -t lY-; \D ^O r^ CO 4 4 <^^£«o M MUM M H M CI OJ 1 DRILLING ON LAND 71 > I— ( o Ph X w o o Q J^ Z M < C O o rt' Z 'o T3 1— 1 ^ »-i >. H PhTJ < c QJ ^ o m c fc 13 o :3 s* bO > H ui; fl C/J O u 1 rt . u o ^ o O •^ . -1 < i2 J- H . wT "(^ C o S « ?. " h- 1 3 -^ .s o 3 ;3 X C CO cr W c c c m rt cAj ^T^ B o £ 1-1 ;- (U 1-1 O CO < Dana Dana Dana Dana Hauer Dana Gilbert Dana Remarks. 12 For particulars see p. t 59 See R. C. & Hill report p. 107 See report on J. A. Hart, P- IIS See "Cofferdam," re- port, p. 75 7-10 cu.yd. For particulars see Buf- falo No. 5, report, p. 244 For particulars see Cien- fugos Harbor report, p. 291 For particulars see Ed- wards Bros., report, p. 171 *o Depth, II Feet. 4 r^ « 1 M IN »- CO -O Spacing, lO Feet. 6X6 10X10 7X7 Various : X X X . ^ .0 <) Kind of Rock. 9 Sandstone Bastard slate Dolomite (L.S.) Limestone Blue sandstone boulder Limestone Coral in Cienfu- fugos harbor, Cuba Sandstone KindofWorkand Holes Fired at Once. 8 River channel. I hole Open cut Open cut 40-50 holes. Cofferdam "dry" River channel, 650 holes Harbor work. Coral formation River channel. I hole Kind of Powder, 7 El, q Qo^^p 60% Potts 60% 60% Pluto 1 ^ P. < Lin.ft. Drilled 6 Lbs. t -^ \n i>- " M 10 N r~ fo H d Cu.yd. Pay, 5 Lbs. to ■ ■ -^ ■ ■ CO 10 ■ - -^ • • 1 .920 0.81 0.327 Cu.yd. Loosened 4 Lbs. IN fO n If to -0 -0 t 7 c CO 2 cts.per cu.yd. 1.266 0.65 0.197 a .s ClJ Lin.ft. Drilled 3 Cents. 1-1 to W M O* fO N N r~ to ■- M (S Cu.yd. Pay. Cents. fO ■ ■ H 72 ROCK DRILLING I U' ">> hH o •-] Ph o h 12: 1—1 H <: O H O U c l-H PH P^ 1 - < Dana Dana Dana Dana Dana Dana Dana Dana Gilbert Remarks. 12 SeeDuluth Crushed Stone report, p. 1.32 See particulars report, p. 260 For particulars see Ex- ploder, rep., p. 199 For particulars see Earthquake, report, p. p. 220 For particulars see Brownell Imp. Co., report, p. 125 For particulars see Hur- ricane, report, p. 231 For particulars see Dyna- miter, C. S. Co. report, p. 206 For particulars see De- stroyer, report, p. 187 Canal excavation mucked and cleaned by ^" steam jet For particulars see Hay Lake report, p. 282 "o Depth. II Feet. S CO '^ 1- M r-jVlCi M n 0\ lOM I c A ■ ■ 1 • - • • >/i ^ ^ TT r^O «« ^ ^HMH MMHM Spacing. lO Feet. ^ ^ ij^ \r, OJ iTilo "^w '•^ -gxxx ^ XX X^ X Kind Rock. 9 Bastard granite Limestone Limestone Limestone Limestone Limestone Limestone Limestone Soft shale Hard Lime- stone. Kind of Work and Holes Fired at Once. 3 Duluth crushed stone River channel River channel, 360 holes River channel, 249 holes Crushed stone quarry, 60-75 holes River channel, 228 holes River channel. 276 holes River channel, 396 holes Cut3o'X9'. 15- 40 holes River channel Kind of Powder. 7 ^Coo0^o_= ot- ojio^ 0^0 tjot go. < Lin. ft. Drilled 6 Lbs. 0. 123 0.984 1 .96 0.84 1.73 0.906 1,96 0.92 Cu.yd. Pay. 5 Lbs. I. 81 2.91 1.23 1.296 2.92 1.24 0, H Cu.yd. Loosened 4 Lbs. \C -O 10 00 !>■ CI M r- N 0, -> t-> 0\ 00 0\ h< o\ M « Vi t~ • 0\ t^ -tT w n IN ■ « ro ir> 00 Cu.yd. Loos- ened. I Cents. Ovt-0\ CO MOO TOC OOOOO M CifO r~oc •<— DRILLING ON LAND 73 > O P^ X o H O < P 1— ( H p^ O Authority. 1,3 Q u V G o C cfl Q '6 <3 £ Ul V & Remarks. 12 ^:gS °S o^ % %St o-| fen O O &H fo<^^ w "o o ■ cfl '-' « a Ph O -O T -T - ■ Kind Rock. 9 S (UO poo^ --c-g^ oo-oo >:-. -J Kind of Work and Holes Fired at Once. 8 o I- c5 d, o. t;^ oj flj rt . ^ -SS -SS W^ Ss ^1 ^-1 .s^ II :h i^i? ?l >" c3 <3 « ^ 1- ^ ^ , ii o s flj Kind of Powder 7 "■ CG O r- >i it o^ < ■ S ^^ .-1 « O p^^ (N o ID QJ CJ ■ -* a ■ >^ a M •S m 5^S o" * r r 00 3 c 1 > 74 ROCK DRILLING > O Ph w o O P < O O U Ph O pq < W H I— I p=i W X 'u o f^ ^ HI < o 6 6 GO 1 d K Remarks. 12 li o a P. i;^ > ^ o 3 s § r > xo < fin CiH « u m Pi eq m pq Kind of Work and Holes Fired at Once. 8 - "! ,5 C S "i C ^ i3 E P s,^ Is III PQ Kind of Powder. 7 o o s 5 § o § 5 rt CD ra vo nJ ™ C G G .J C fi : Q Q Q o Q P o'c 4-1 0) o bo < «^3 M O CO M M H rt lO o id - c3^ -> C4 "3 PO N 1- 00 Oi c H H t- :>'»o^ §"- Si2 ^i §"^2 « " o a •" ■ ■ "- — — ^«j -.I 1 u a u -5 o> 6^ "J >. oj w C • * < c ^ C n 1- 1 t- T it c * * 1 CHAPTER IV DRILLING ON 'LAND—iCofiliuued) Livingstone Improvement of the Detroit River, Cofferdam Work. The so-called Livingstone Improvement of the Detroit River is located near Amherstburg, Ontario, and is for the pur- pose of making a new channel 300' wide and 23' deep at mean water level, for down bound vessels. The whole job was divided up into four sections and was contracted for by the follow- ing firms : Sec. No. I J Great Lakes Dock and Dredging Co. Sec. No. 2, Grantj Smith & Co., and Locher. Sec. No. 3, O. E. Dunbar and T. B. McNaughton. Sec. No. 4, G. H. Breymann and Bros. 4000' of Sec. No. 2 comprise the so-called "dry work." The southern 1500' of Sec. No. i are also dry work. Part of this cofferdam work adjoins Stony Island, and where such is the case no cofferdam need be built. The northern dam of the 4000' before mentioned, instead of being built at right angles to the river, was made to follow the old line of the Michigan Central R. R. piers, which were on a curve. Due to this fact 300' were left unenclosed at the eastern end of this dam which later was taken care of when the southern 1500' of Sec. No. I were enclosed. The work of damming in the 4000' began April 4, 1908, and as it progressed it was seen that all could not be enclosed before winter set in. For this reason an aux- illiary dam was thrown across, 1200' up stream from the end of the 4000' section, so that the work of excavation could be carried on during the winter. There were 112 acres of land in this final enclosure having an average depth of water of about 12'. It took 12 days to pump this dry. The apparatus used in removing this water was as 75 ROCK DRILLING ■-^ri'^y--T*\:_" Fig. 31. — Livingstone Improvement. Fig. 32. — Dry Work — Detroit River Cofferdam. DRILLING ON LAND 77 follows: 2 1 2-inch Morris centrifugal pumps, 49 S-inch water lift pipes. These pipes are also known as *' Serpents." They are 8-inch cast iron pipes braced in an inchned position, their lower ends being about 2'^ from the bottom and the upper ends emptying into the river. They are operated by a small air pipe that runs down along the side of the larger pipe, curls up around the bottom and into it. From 15 to 20 lbs. air pressure were used on these sma 1 air pipes. Their total lift was about 12' and their capacity 40,000,000 gallons in 24 hours. The two 12-inch pumps were good for 10,000,000 gallons per day, making a total of 50,000,000 gallons in 24 hours. Sketch Shoiving Position of Dams A drained first B " next C " last A & B & C finally to be one Fig. t,3. At the time of this investigation, August, 1909, the remaining 1200' of Sec. No. 2 and the 1500' of Sec. No. i had been enclosed. These dams were, all told, some 16,000' in length, contained about 300,000 cu.yds. of material, and took 12 working months to construct. Where the nature of the bottom permitted it, the bank was built by dredges. Where this was not feasible, scows loaded with broken limestone from the channel were dumped along the line of the dam until so much material had been deposited that the loaded dump scows would no longer float. The type of scow that carries a deck load was then used in conjunction with a derrick boat that unloaded them. This derrick boat has a long boom that overhangs the loaded scow. Near the ends of 78 ROCK DRILLING Fig. 34- — Upper Section — Livingstone Improvement. Fig. 35. — Derrick Boat on the Livingstone Improvement. DRILLING ON LAND 79 this boom are sheaves over which a cable passes. This cable passes around a drum and has its tsvo ends secured to a scraper. As the drum is revolved by an engine, the scraper is operated back and forth across the deck of the scow, quickly unloading it. As soon as the 2800' section was enclosed, the work of taking out the rock began. Three similar plants were installed for this purpose. Each one, with the necessary pumps, consisted of a drilling and blasting outfit, a 60-ton Marion shovel, an aerial cableway and skips, and a channeling machine. One traction drill as an experiment was also in use. All drills, cableway engines and the four pumps were operated by air. This com- pressor plant was the one previously used by the same con- tractors on West Neebish Channel. Drills. During the latter part of August, 1909, when these observations were made, there were 14 air drills working. The tripods elevate the drill cylinder so that there is a few inches over 2' between the ground and the U-coupling or chuck. This of course necessitates the use of different sized bits. These bits range in even sizes from 2' to 16' in length. The drills are known as the Rand "Little Giant," and are marked 3 K.D.M.5. A feature of this drill is the ^'Sergeant rotating collar" that holds the dogs which mesh into the rifle nut. This is a friction collar which is held on by the friction cap. It is very useful when the bit becomes stuck. To take an extreme case, suppose that the bit enters a pocket in the rock that is nearly square in section. Obviously, since the bit has to revolve to work properly, it would in this square hole do one of two things if this "collar" were rigid and immovable: (i) stop the drill; or, (2) break the bit. When the bit first gets into this square hole, it naturally tends to stop or break the bit, but with this arrangement, when a certain twisting force is felt on the bit this collar slips. It slips before the twisting force is great enough to do either of the two things mentioned, but the pressure exerted in causing it to slip has the effect of causing the bit to take off some of the corners of the square hole. Then as the bit is raised and lowered a few times, the action is repeated and soon the so ROCK DRILLING Fig. 36.~Drill at Cofferdam B. Fig. 37. — Drilling at Cofferdam B. DRILLING ON LAND M square hole is round and the machine can go on with its regular work. In this drill also the rifle nut has an odd number of teeth. The effect of this is that only one of the dogs engages in the rifle nut at a time, and as a result, the twisting action of the rifle bar exists when the stroke is only half its normal length. Drill Data : Rand drill, Little Giant, 3 K.D.M.5. Diameter of piston, 3 J". Stroke, about 7". Lift of cylinder, 2'. U chuck Air pressure, 90 lbs. at compressor. Strokes per minute, 350. The drill is moved by the runner. After a hole is finished, the bit is taken out of the hole and the weights are removed from the legs of the tripod. The runner then puts a cloth over his shoulder, gets under the tripod and moves the whole machine over until it is in its new position. On this job there are two types of bits used : one for very hard rock, and the other for the softer grades of rock. The type for the hard rock is smaller in diameter at the point than the other type. The rock on this job is not hard and so the first type of bit is not used regularly, but only in the block holes. Block holes are used where grade has not been made by the regular drills but after the blast a "table" has been left. The small drills are then used to drill through these tables. Regular Bits Lenstb, Diameter of Steel, Diarreter of Bit Feet. Inches. Peine, Inches. 04 Starter, 2 if 4 If 6 If 3f 8 If sh 10 i^ si 12 li 3i M li 3i 16 il 3 82 ' ROCK DRILLING Hard Rock Bits (Block Hole) Length, Diameter of Steel, Diameter of Bit Feet, Inches. Point, Inches. Starter, -j. 2\ 4 2I 6 2I S A 10 ? i^ A 14 if 16 if The kind of point is the common + point. Section of steel, octagonal. Point tempered till file won't touch. In drilling the holes no jet is used. The hole is kept well filled with water by the helper. At each change of bit the dirty water is taken out. The apparatus used for doing this is a piece of pipe about aV long by \\" in diameter, through the inside of which runs a jointed rod terminating at one end in a handle, and at the other in a plunger that closes the lower end of the pipe. To remove the water the pipe is dropped into the hole and then drawn out by the handle. In doing this the plunger at the end of the rod closes the lower end of the i-V' pipe, and the water is retained in it. To empty, the rod is simply forced out thus opening the end of the i^' pipe. Holes, 13' deep and 4-^' in diameter. Longitudinal spacing, 8'. Lateral spacing, 4' and 6', mostly 6'. Material, limestone, solid and not very hard. Forty to fifty holes shot per blast. Pluto powder used. Sticks, ii'X8". Glycerine per cu.yd. loosened, 0.422 lbs. Blasting battery used for setting off blast. Two blasters, 2 helpers, i cleaner and i helper, compose a blasting gang. The boilers used at the compressor plant are three in number? each 210 H.P. Each is 20' long and y'y" across, having 84 4-inch tubes with a 30-inch steam dome. They were made by the Erie Iron Works. Fig. 38— Drill Scow— Thousand Islands, St. Lawrence River. Harbor— Johnston & V'irden, Contractors 83 84 ROCK DRILLING The compressor plant consists of two Rand Drill Co. units, each two-stage. The intakes of each low pressure are mechan- ical, and the outlets automatic. The capacity of the larger machine is 5725 cu.ft. per minute, while that of the smaller is 1900 cu.ft. per minute. Each low pressure raises the air to 30 lbs. and the high pressure can take it up to 95 lbs., but it usually runs at 90 lbs. The temperature of air at 95 lbs. is about 200° F. The numbers of the low pressure and high pressure respectively of the large machine are Nos. 2127 and 2126. The large machine is operated by 2 Newburg engines, having a pressure of 150 lbs.; 350 H.P.; 4' stroke; large Cylinder, 40"; small cylinder, 22"; 75 revs, per min. The small machine is operated by two Hamilton Corliss engines running at 95 revolu; tions per minute and having a pressure of 150 lbs., and 400 H.P. The cylinders are respectively 30'' and 17'', and stroke of each 30". This compressor plant is the same as that used on West Neebish channel, and depreciation was figured at 25% on that job, which is roughly 6% per year. As has been said this compressor plant was used for the operation of the 3 cableway engines as well as the drills. It is estimated that half the plant capacity is used for each purpose. The contract reads for 750 good working days. The con- tractors say that it will take a year to finish the work. The drill crews of the two upper shovels work two 8-hour shifts, 8 A.M. to 5 P.M. and 6 p.m. to 3 a.m. The drill crews of the lower shovels work three 8-hour shifts. The shovel crews work only two shifts, 8 to 5 and 6 to 3. Each tripod drill has one runner and one helper. The trac- tion drill also is operated by the same number of men. The runners get $2 per day and the helper $1.75 per day. The contract prices are, for rock, $1.24 per yd.; for earth, 60 cts. per yd. The work of the smith is mainly rcpointing the drills and sharpening the channeling irons. The coal is brought by boat to the dock and unloaded into a DRILLING ON LAND 85 ^^^^ff^m^ Fig. 40, — Livingst.jne Improvement. Fig. 41. — Loading Holes for Blasting, Livingstone Improvement. S6 ROCK DRILLING 4-ton large chute. A dinkey, drawing a flat car which carries ij dump boxes, gets a load and draws it about J a mile to the boiler house supply. Here a jib crane lifts the boxes off the flat car, swings them over to the pile, where the boxes are emptied by turning them upside down. i8 tons per day at the compressor plant and 2' of this or 9 tons, or 946 lbs. per drill per shift are charged to drilling. Thirty cents per ton is the cost of handling the coal. At the compressor about 3 qts. of oil are used per day. At the drills 2 pts. of oil are used per drill per shift. Fig. 42. — Drilling — Livingstone Improvement. The repairs on the West Neebish contract cost $9765 for 1000 working days. On this basis repairs per drill day were roughly $1. Interest and depreciation on the 10 drills, including the compressor and boiler plant, at 2% per working month on $16,000 ^20 ^ , = ^^ = $12.30 per day. Superintendence. During the month of June, 1909, there was one superintendent on the job and 10 foremen. These men had charge of 20 drillers and also the other employees, such as shovel men (3 shovels), cableway men (3 cableways), pumpmen and laborers. DRILLING ON LAND ■ (N N W > „ VO t , ■ tn t/! CO O O ^^ u ^^ ^~ "^' -t r^ O O C>. yy. -t ^666 • ■■€) CO t--, X x^8 8 ^^ ^^'8 < «« H ■^ o o o ; M CO X X lo in O M fpoO .' . vo" ■^ r^ o' lo t^ ' c/i cfl t/i i2 o oo i2 ^ -c -^ u o Oifiu ^ U-, -rt- O n o O - '^ ir: H CO ^' t~- i>- m '"' o o o . 00 t~- -t M LO o - • . . CO " vO i^j f^ ' M ^0 -^ ^ •^ >H* O" ro ) O "^ xi "" ' O t^ t~* U — . — — ■^ ^^ ^ O ii-,CO • c^ ►■ 4j© ^ ^' li-i O , O " -o Q in U-, ro ^' X ":. o o o "^ O LT) O 1^ ""J ■^ oO Lo lo '^ ""^ , u o o i*-! ^ — ^ „ M u-,OC ON ro — J= — CO ^ On I o o o to -M O O ^ O O 3 . O C ^ 1) 3 -^ to w-i lU ^ Ot3 o ii-^ " Gh^ bD4^ >nm ih iH n C o "^ ^ ^ :^ o o ^ n ^-r; C u £ 3 P -^ O (_, -^ O U to '*^ (D 1-, |_( )_, "p - Q. QJ (U (U b S.S.fi o J-. E M ■':^ CJ 1) OJ -^ CO CO CO ^ i-t "^ ""O ""O fi ■ i ^ t^ ^ =3 ^ t-^-^ ■'^ ROCK DRILLING Fig. 46. — Loading by Hand into Skip. Fig. 47. — Loading Rock with Steam Shovel. DRILLING ON LAND 93 The following figures which give the cost with a tripod drill per lineal foot drilled and per cu.yd. of pay rock loosened are based on the average performance during 204 days, covering a period of 8 months, January to August inclusive, 1909. MATERIAL— SOLID LIMESTONE Days worked 204 Total number of holes 26,327 Total lineal feet 175,501 Total cubic yards of pay rock . . 273,750 Total cubic yards of blastedrock 314,000 Lineal feet per day 840 Av. cubic yards pay rock per day 1,390 Av. cubic yards blasted rock per day 1,538 Av. No. drills, 9^ (2 shifts of 8 hours) = 19 per day Dynamite, 60% 139,850 lbs. Dynamite, 40% 120,650 " Total dynamite 260,500 " Total nitroglycerin 132,170 Average dynamite per day . 1,179 ^^^s. Av. nitroglycerin per day . . 650 ' ' Av. nitroglycerin per cubic yard pay rock 0.484 " Av. nitroglycerin per cubic yard blasted rock 0.422 " Force. Standard Rate. Amount. Basis of Costs Cost per Lin. Foot. Cents. Cost per Cu. Yd. Pay. Cents. ig drillers at - . 19 driller helpers 8 nippers 2 blacksmiths 4 blacksmiths' helpers. I engineer, day 1 engineer, night 2 firemen 00 75 50 00 75 00 00 00 $38.00 33-25 12.00 6.00 7.00 3.00 3.00 4.00 $25.00 $10.00 .98 1. 19 5.13 1.80 Total drilling labor Coal, 9 tons at $3 . 50 . . Oil, 2 quarts per drill at 0.30. 31-50 1-43 $106. 25 32.93 12.65 3-92 7.65 2.37 Total drilling 5 powdermen at $2.00 6 helpers at $1 . 50 1179 lbs. dynamite at 0.12. 1 25 exploders at 0.03 10.00 9.00 141.48 3-75 $139. 18 19.00 145.23 16.57 2. 26 17.30 10.02 1.37 10.43 Total loosening Int. and dep. on ±0 drills and nec- essary compressor and boiler capacity at 2% per working month $16,000 $303-41 $12.30 36.13 1.46 21.82 0.89 Total cost of drilling per drill per shift = 315-71 %-34 37-59 22. 71 91 ROCK DRILLING In the tabulation of costs on page 93 no account has been taken of contractor's overhead charges or superintendence, organiza- tion or preparatory expenses, insurance, accidents, charity, repairs, legal, medical expenses, etc. TIME STUDY— Dec. 31, 1909 Lineal feet drilled during observations, 32 Observed time, 7 hr. 25 min. 25 sec. Cycle time, 5 hr. 40 min, 20 sec. Idle time, I hr. 45 min. 05 sec. KIND OF ROCK— LIMESTONE No. of Obs. Min. Min. Sec. Mean. Min. Sec. Max. Min. Sec Time. Consumed Min. Sec. Per Cent of Total. Time. Drill cutting Raising drill Loosening Removing bit Getting bailer Bailing Getting and dropping bit in hole Inserting in chuck Tightening chuck Getting started 16 16 16 16 13 13 13 13 13 13 Cycle totals Moving drill over and ge Miscellaneous delays. . . . tting St Total time. 20 25 IS 45 OS 10 2S 05 53 49 34 23 28 55 24 20 54 09 19 SO I 30 I 4S o 40 o 50 30 10 40 40 5 245 13 9 6 6 38 II 5 10 4 25 25 55 10 50 arted, 2 19 49 obs 33 55 3 40 20 70 50 34 IS 445 25 = 7hr.25 55.1 2.9 2. o 1.4 1-4 8.6 I. I i.o 2-5 0.4 76.4 15-9 7.7 100. o m. 25 s. Cutting speed 0.1305' per cutting minute = 7.830' per cutting hour. idle time cuttmg time Ratio 7—. =0.^51. total time Ratio cycle time =0.31. Cycle time, exclusive of drilling, = 95 m. 15 s. for 32^=3 m. per lineal foot of hole. DRILLING ON LAND 95 Fig. 4S. — DflroiL River Cofferdam. Fig. 49. — One of the Head Towers. 96 ROCK DRILLING Fig. 50. — Pump. TIME STUDY Obs. time, 3 hr. Traction drill, type Ingersoll-Sergeant Cg. No. holes, 8. Lineal feet drilled, 56^. MATERIAL, SOFT LIMESTONE No. of Obs. Min. Min. Sec. Mean. Min. Sec. 1 Max. i Min. Sec. Time. Consumed Min. Sec. Per Cent of Total. Time. Drill cutting 8 8 8 7 8 8 10 45 35 15 1 00 00 12 50 II 56 41 1 09 I II I 16 07 14 10 45 2 40 2 30 2 15 35 95 25 5 25 9 10 8 15 10 10 I 00 53-0 3-0 5.1 4.7 5-6 0.6 Raising drill Preparing to move back. . Moving back Lowering jacks In position, not working. Cycle total 16 20 22 55 129 25 27 00 23 35 72.0 15.0 13-0 Miscellaneous delays. . . Moving to new range. . . Total 180 00 100 ' Cutting speed = o.59 'per cutting minute. Cutting speed, tripod drill, 0.1305' per cutting minute. Above due to the much larger type of drill. Ratio cuttmg tune = 0.53- Ratio - idle time -=0.389. total time '^ cycle time Cycle time, exclusive of drilling,=34 min. for $6Y = ^6 sec, per lineal ft. drilled. Same for the tripod drill 6 min. and 15 sec. DRILLING ON LAND 97 Q < PQ Pi > o o . . CJ- . i 1 C rt nJ o 1 1 O Ih ■!-■»-> O rt fe (l> x; ■*-> - ^^^g H C£^-2 l-> l-I Rema cernin ter of Locat j 1 1 2S ^ ■ 1 J^H in ] - Is 53 o 1 ,^ •d ■ 5 dg'^K i ■n ^ B-^ ■fi -- w : ) 1 < — ' 1 "o „ 1 d d n (- °og5 Oo§H « 1 O ^•>' « w ^■-iS 1 < -Qt) , i- 5 "o^ O c (U Cfl T* f^ «oSS ri <2 ^s 1- Q ^ ^-o 1 1 -w H O >• M ^ < c ClI 'Z 1 u 1 -3S 1 1 1 1 ' _JJ p s 1 +J o la 6(2 CIS O &iK u ! " UJ •t l~H w . O .u H o* H M fT* lOvO l>00 Ov O w « fo -v m-o 1^00 CT o - n mT v.\o »-oo Oi o M So. 1 u Q 98 ROCK DRILLING This shows very clearly the great saving of time due to not having to change steels during drilling. The two great advantages of the heavy traction drill over the small tripod drill are this great saving in time due to not having to change steels during the process of drilling, and the much greater cutting speed due to the use of much larger drills. The above figures very clearly show this. It is to be noted, however, that there are not many cases where conditions are as ideal as they were here for the use of a traction drill. The surface of the limestone was here practically level, and the cut being 300' wide and some thousand feet long a traction drill was indeed a great innovation. CHAPTER V DRILLING ON LAND— Continued D. L. & W. Cut-off. The so-called D. L. & W. Cut- off is a new undertaking of the Delaware, Lackawanna and Western Railroad for the purpose of shortening the old line from New York to Buffalo. The cost of the work is estimated at $9,454,154 and the date set for its completion is August, 1911. This new line will be 28.45 ^^il^s in length and will join the old line at Hopatcong on the east end and Slateford on the west end. The purposes of this work are three-fold: shortening of distance, reducing the grade and avoiding tunnels. The distance saved is II. 12 miles eastbound and 10.53 J^il^s westbound. The ruling grade eastbound is to be 0.55% compensated, or 29.04' per mile, against 1.05%, or 55.44' per mile, on the old line. This will be a saving of 26.4' per mile eastbound. Westbound, the new ruling grade is to be 0.75% compensated, or 39.60' to the mile, against 1.39%, or 73.39' to the mile, on the old line. This means a saving westbound of ^^.S' to the mile. Two tunnels, the Oxford and the Manunka Chunk will be avoided. It was originally intended that the new work should have no tunnels, but near Andover, N. J., the seamy nature of the rock made an open cut dangerous and so a tunnel is being driven there. In the line of bridges there are to be seventy structures from a 3' box culvert up. The most handsome struc- ture is that across the Delaware near Columbia, N. J. It is composed of concrete arches and is very artistic. The contract for the whole work has been let in seven sections, approximately 4 miles in length. Beginning at Hopatcong, the eastern end of the new work, the sections and contractors are as follows : 99 100 ROCK DRILLING Sec. I, Timothy Burke. Sec. 2, Waltz and Reece. Sec. 3, David M. Flickwir, Roanoke, Va. Sec. 4, Gehagen. Sec. 5, Hyde, McFarlane and Burke. Sec. 6, Reiter, Curtis & Hill, Phila. Sec. 7, Smith-McCormick. On Sec. 7, the Smith-McCormick Co. are constructing the arches across the Delaware and have sublet the other work to James A. Hart of New York. Due to the rocky nature of the work much drilling and blasting has been necessary. Sections 3, 6 and 7 are typical of this, and the following observations concerning them have been made. D. M. Flickwir, Sec, 3, Andover, N. J. Engaged in drilling operations on Sec. No. 3, D. M. Flickwir has 17 Ingersoll-Rand drills operated by air pressure. Two compressors of 2250 cu.ft. capacity are used to furnish the necessary air at no lbs. pressure. On that part of this section nearest Andover, N. J., the rock loosened by drilling and blasting operations is used for making a large fill. The method employed in making this fill consists of a suspended track arrangement as follows: Two large cables about 7' apart, and anchored at their ends, pass upward over wooden towers for abutments and furnish support for the vertical cables by which the track beneath is suspended. There are three sections of track thus suspended and the vertical suspending cables are so arranged that as the fill progresses the track may be pulled forward into its new position. It is on this section of the work that the only tunnel on the new line will be located. The dip of the rock, bastard granite, was here so sharp that on account of the earthy material between the strata it was feared that an open cut would be too dangerous. This tunnel is to be called the Roseville. At the time this work was investigated the heading on this tunnel had been nicely started and holes had been drilled for the next blasting. The scheme used in arranging the holes and the method of blasting are as follows: The curve of the arch was painted on the rock in red, and holes (so-called outside rounds) were drillied on this line about 3' apart. Six feet each DRILLING ON LAND 101 way from the center there is a row of holes placed about 15'' apart from bench to outside rounds. These holes, 10' in depth, all point toward the center so that a V-shaped chunk of rock Fig. 51. — Drilling at Andover, N. J. Fig. 52. — The Bench at Andover. known as the *'cut" may be loosened when blasted. To assist the cut holes another row of holes 6' deep and similarly spaced is drilled midway between. 102 ROCK DRILLING On each side and about half way between the "cut holes" and the "outside rounds'' measured along the bench there is a row of holes in a plane at right angles to the face known as the "side rounds." They are spaced about 15'^ apart from bench to out- side rounds, 10' in depth and drilled at an angle of 75° with the vertical. Midway between the "side rounds" and "cut holes" there is another similar row of holes on each side known as the "quarter rounds." In blasting, the "cut holes" are first shot, the charge being 6 sticks of 60% dynamite (8"XiJ"). Quarter rounds are next shot, then the side rounds, the charge for both being 4 sticks. The outside rounds, each loaded with 3 sticks, are shot last. The idea of the small charge and this method of shooting is to make as clean a cut as possible without shattering the adjoining rock too badly. In work of this kind drills are in nearly a horizontal position and do not work, of course, as efficiently as when in a vertical position. Drill Data: Ingersoll-Rand. 3J-inch piston. 6-inch stroke. Feed 2'. U chuck. 100 lbs. pressure at compressor. 400 strokes per min. In moving drills from one place to another the drill cylinder and slide are taken from the tripod and the drill cylinder and the slide separated. Bits are made of lY' steel, tapered off to i^-'', to fit in the chuck. The 2-foot bit is 3" in diameter at the point, and for each increase in length of 2' the diameter at the point becomes -|" less. Points are of this shape +. The steel is handled by workmen who carry it from the drill to the blacksmith shop. They are sharpened by hand with the aid of a smoother. No jet is used, but wash water is poured in by the helper from a can. An air wash-out is used on the "outside rounds." These holes are drilled without water, being so nearly horizontal, and to t^et rid of the powdered stone, this air wash-out is used occa- DRILLING ON LAND 103 sionally.i Holes are drilled on the tunnel heading lo, 8 and 6' in depthj as already stated- Holes 4'' at top. Spaced about 15" apart vertically. About 3' apart horizontally. Holes drilled with drill, making an angle of about 75"" \vith vertical. Rock, hard bastard granite, very seamy and difficult to drill. Holes shot as already stated. Dupont Powder used. Sticks S'^XiJ". 100 sticks = 5o lbs. 17 drills. Two compressors, Kiernon, capacity, 550 cu.ft. Ingersoll, capacity i7cx> cu.ft. Pressure, 100 lbs. at compressor. Feed main, i-^- miles long, 6-inch main, 4-inch branch to 2" . From the 4-inch branch a 2-inch pipe runs to a T from which ij-inch flexible piping runs to the drills. Work to be completed August, 191 r. Shift ID hours, i shift per day. DRILL LABOR— Standard Wages 17 drill runners at S2. 50 = $42. 50 17 drill runners' helpers at 1.7^= 29.80 2 blacksmiths at 3 . 00 = 6 . 00 2 blacksmiths' helpers at i, 75 ^ 3-5° 4 nippers at 1.50= 6 . 00 3 powdermen at 2.00= 6.00 I engineer at 3 . 00 = 3 . 00 I fireman at 2 . 00 = 2 , 00 T water carrier at 1.50^ i-5o Total drill labor Sioo. 30 Superintendence. One man in full charge of field. One foreman for the drillls on the heading, 2 other foremen for the other two s;ano;s of drillers. ^ It consists of an inch pipe about 15' long connected by a rubber hoso to the air line. 104 ROCK DRILLING Fig. 54. — Face of Rock, Andover. DRILLING ON LAND 105 The work of the smiths is to repoint drills and do odd jobs of repairing. Coal used, 8 tons per day or 940 lbs. per drill per day, I shift. Oil used at compressor, 4 gals, or i,88 pts. per drill per day, I shift. Oil used on drills, 2 pts. per drill per day, i shift. Coal is dumped on trestle and costs $3.10 per ton delivered. (Standard assumed $3.50 per ton.) Drilling plant of 1 7 drills and necessary compressor and boiler capacity valued at $14,300. Interest and depreciation on same at 2% per working month, = $11.00 per day, = 65 cts. per drill day. Moving drill from hole to hole and getting started amounted to 22.4% of total time (drill working in tunnel heading), costing 22.4% of drill labor $6.11 =$1.37 per drill per day, i shift. As said, there were three drills at work on the tunnel heading. The drill which was timed was set up on the bench on its tripod as usual. Another was set up on a cribbing of ties. The third was set up on a column. The cost of drilling per lineal foot in hard seamy bastard granite in tunnel heading is based on the above performance of 24 lineal feet in 7 hours, 27 minutes, 20 seconds, or 32' in 10 hours. No account is to be taken of overhead charges, superintendence, repairs, storage, organization and preparatory charges, charity, accidents, legal or medical expenses, etc. 106 ROCK DRILLING No. OF Drills, i; Linear Feet, 32; Kind of Rock, Bastard Granite Force. Standard Rate. Amount. Cost per Lin. Foot, Cents. I drill runner. I drill helper. . 2 blacksmiths for 1 7 drills 1 blacksmiths' helpers for 17 drills. I nipper for 3 drills I water carrier for 3 drills I engineer at comp. (17 drills), per day. I fireman at comp. (17 drills), per day.. Total drill labor. Coal, 8 tons for 17 drills Oil (at comp.) 4 gals, for 17 drills, per gal. Oil, (cylinder) i qt. per drill, per gal Total drill expense Int. and dep. at 2% mo. on (iVX 14,300), •50 .75 .00 •75 ■50 .50 .00 .00 3-5° 0.30 0.30 ■75 o. 21 0.50 o. 50 0.18 O, 12 $4.25 $1.06 0.50 0.18 0,12 $1.65 $1.65 0.08 0,08 0,16 7.92 '^Z'2P 1-56 0.56 0-37 19. II 5-i6 U.50 24.77 2.0 Linear Feet Drilled, 24; TIME STUDY Rock, Bastard Granite; VERY Solid Condition of Rock, No. of Obs. Min. Min. Sec Mean. Min. Sec, Max. Min. Sec. Total Time, -Min. Sec. Consumed Time, Per Cent of Total. Drill working Raising drill Loosening chuck Removing bit Putting bit in hole Inserting bit in chuck . Tightening chuck Getting started 00 00 00 00 00 00 00 oc 10 10 10 15 10 20 10 22 00 00 00 00 00 00 00 56 23 19 45 32 40 37 31 49 00 00 3 00 40 30 05 05 5° 05 00 61.6 0.9 0.8 1.8 1,0 I. 2 1. 1 0.9 Cycle totals Shifting drills and getting started - . Miscellaneous delays 13 25 26 43 58 15 ZZ 23 Totals- 309 50 100 10 37 20 69-3 22. 4 8.3 447 20 (i) The cutting speed was 0.0872 ft. per min. Rock was very hard and seamy and drilling was done with drills in nearly a horizontal position. (2) Ratio of cutting time to total time was 0.616. (3) Ratio of idle time to cycle time was 0.444. DRILLING ON LAND 107 Reiter, Curtis & Hill, Sec. 6, Vail, N. J. Section No. 6 on this D. L. & W. cut-off is being constructed by Reiter, Curtis & Hill, of Philadelphia. Engaged in drilling operations on their section are i6 Ingersoll- Sergeant drills. Type F 24. They are being operated by air furnished by two 250 H.P. Ingersoll-Rand compressors at 100 lbs. pressure. The rock in the main cut is locally known as bastard slate, and on account of seams is very mean material for the drills to work in. Drill Data. Ingersoll-Sergeant drills, type F 24. 3i-inch piston. 6-inch stroke. 2' 9'' feed, but steels change in length by 2' each time. U chuck. }co lbs. pressure at compressor. 350 strokes per minute. When drills are moved, they are removed from the tripod and each moved separately and then set up again. Starting bit 3^^' at point. 4' bit 2)Y^ ^t point. 6' bit 3'' at point. 8' bit 2f " at point. to' bit 2\" at point. 12' bit 2^" at point. 14' bit 2" at point. Bits made of \\' material; somewhat less at the end to fit in the chuck. Points are this shape +. Men carry the steel back and forth from the drills to the blacksmith shop. The bits are tempered till a file will not touch them. Points are put on by hand assisted by a smoothing iron the shape of the bit. Wash- water is poured into the hole from a tin can by the helper. An air wash-out is used, consisting of a f-inch pipe connected to a small rubber hose which is in turn connected to a cock 108 ROCK DRILLING tapping the air line of the drill near the air chest. This agitates the wash-water, thereby keeping the point of the bit free from dirt. The hole is bailed after each 2' section is drilled. The bailing device is a piece of pipe about 2' long and i.\" in diameter. A rod of steel, y section, passes through this pipe and has a coni- Fig. 55.— Tripod Drill at Vail, N. J. cal piece of metal on its end that closes the end of the i|" pipe. In operation the pipe is let down into the hole by the rod and by allowing the rod to drop a little, the dirty water comes into the pipe, seeking its own level, then the act of lifting out the pipe by the rod causes the stopper on the end of the rod to plug up the hole in the pipe. To empty, the pipe is rested DRILLING ON LAND 109 on the ground, and the plug being forced out the water runs out. Holes 12' deep. Spaced 10' laterally. Spaced 10' longitudinally. Holes about 4^'' at top. Holes make angle of about 15"^ with vertical. ,FiG. 56.— Character of Rock, Vail, N. J. Material — Bastard slate, hard and seamy, although somewhat shaken from previous blasts. From 20 to 40 holes are shot at a blast. Dupont dynamite used, 60%. 110 ROCK DRILLING Sticks, 1^X8", \ lb. each. The holes are first sprung with from 4 to lo sticks of dynamite and then charged. Charges are about 50 lbs. of dynamite to a hole. Blasting machine used to fire the charges. Fig. 57. — Charging Holes, Vail, N. J. The foreman of each gang of drillers has charge of the blasting. Assisting him are 3 powder carriers and tampers. Sixteen drills are in the outfit, but only 7 were working at the time of this investigation. Two 250 H.P. compressors. Steam cylinder 24X30. Air cylinder 24 J X 30. DRILLING ON LAND 111 Five Erie boilers of loo B.H.P., also i extra Erie boiler of loo B.H.P. 100 lbs. pressure at compressor. Feed pipe about J mile long; lo" reducing to 6^', then to 4'' and 2'^ The 2" pipe leads to a T near each group of drills,; from which separate lines run to each drill. These lines are made up of i\" piping terminating in a length of i^-inch hose that connects to the air chest of the drill cylinder. Job to be finished August, 1911. Shift, 10 hrs. One shift per day. The following drill force were at work at the time of this investigation. Standard Basis of Costs. Cost per Day. Total Cost. 7 drillers $2.50 $17.50 1.75 12.25 1.50 6.00 3.00 3.00 1.75 1.75 r.50 3.00 2.00 6.00 3.00 3.00 2 . 00 2 . 00 7 drillers' helpers 4 muckers I blacksmith 1 blacksmith's helper . . 2 nippers 3 powderm.en I engineer I fireman Total labor ScA Co Superintendence. One general superintendent, 2 foremen, one for each of the two groups of drillers. Interest and depreciation on 16 drills and compressor and boiler of the necessary capacity, valued at $18,075, ^^ 2% per working month, =$13.90 per day (i shift). Moving drill from hole to hole and getting started took 21.3% of the total time, and on the above basis of wages, exclusive of powdermen, cost $1.48 per drill per day (i shift). Coal used, 7 tons per day, or 875 lbs. per drill per day of i shift. Oil used at compressor, 4 gals., or 2 pts. per drill per day. Oil used at drills, 3 pts. per drill per day. 112 ROCK DRILLING Fig. 58.— Vail, N. J. Fig. 59.— Vail, N. J. DRILLING ON LAND 113 Cost of Drilling and Loosening in Bastard Slate. Based on the observed performance of 34 lineal feet in 7 hrs., 24 min., 35 sec. (see time study) or 46' in 10 hrs., and the perform- ance of 3 other drills at 42', 40', and 42' respectively, the following deductions as to the cost of drilling per lineal foot have been made. Holes being spaced 10' centers, average depth 12' and 50 lbs. of 60% dynamite being used per hole, the following cost per cubic yard of material loosened has been deduced: Fig. 60.— Vail, N. J. 114 ROCK DRILLING No. OF Drills, 4; Lineal Feet Drilled, 170; Cubic Yards Blasted, 630. Total dynamite, 60%, 700 lbs. = i.n lbs. per yard. Total nitroglycerin, 420 lbs. = 0.666 lb. per yard. Total nitroglycerin, 420 lbs. = 2.47 lbs. per linear foot. Material, Bastard Slate Rate. Amount. Standard Basis of Costs Cost per Lin. Foot in Cents. Cost per Cu.yd. in Cents. 4 drill runners 4 drill runners' helpers. 4 muckers ^ smith I smith's helper. I nipper 4/16 engineer. 4/16 fireman. - Total drilhng labor. Total drilling. Dynamite, 700 lbs., 60%. 14 exploders 3 powdermen. b2.5o 1-75 3.00 1-75 1-50 3.00 2.00 7.00 6.00 $23.00 0.87 $3-87 0-75 0.50 $ 1.25 $28.12 Coal 7/4 ton Oil at compressor plant 16/7 gal.. . Oil at drills, 3 pts. each drill 3.50 0.30 0.30 6. 14 0.69 0.45 $7.28 5-40 o. 12 0.03 $84. 00 o, 42 6.00 Total drill and blasting. . . . Interest and depreciation on 4/ i6of $18,075 (estimated value of drill- ing plant at 2% per working mo.) 54.42 6,00 $125.82 Total. 3 -48 $129.30 13-50 2.28 0.74 16.52 4.29 49-55 73-^ •05 75 ■ 93 3-66 0.62 4.^ r.i6 5-64 13-39 0-95 19. c 0-55 20-53 The fact that four muckers had to be employed here accounts for the increase in cost per drill per day over the same items on the other two jobs on this work. In the above tabulation of costs no account has been taken of contractors' overhead charges, superintendence, organization, or preparatory, repairs, insur- ance, accidents, charities, legal, or medical expense, etc. DRILLING ON LAND 115 TIME STUDY Linear Feet Drilled, 34; Rock, Bastard Slate; Condition of Rock, Seamy and Badly Shaken in Places from Previous Blasts Drill cutting Raising drill Loosening chuck , Removing bit Putting bit in hole Inserting bit in chuck. Tightening chuck . Getting started. . , Cycle totals Shifting drills and getting started Miscellaneous delays Totals. No. of Obs. 17 17 ^7 17 14 14 14 14 Min. Min. Sec. 3 00 00 00 00 00 00 00 3 40 Mean, Min. Sec. II 00 00 GO GO 00 00 00 14 16 47 18 Max. Min. Sec 21 15 15 40 40 00 40 00 20 27 50 Total Time. Min. Sec, 20 10 20 30 20 00 00 05 238 45 94 35 III IS 444 35 Time Consumed : Per Cent of Total Time. 44-7 2.7 i.o I. 2 1.6 0.9 0.9 0.7 53.7 21.3 2S.O (i) The cutting speed was 0.172' per min. (2) Ratio of cutting time to total time was 0.447. (3) Ratio of idle time to cycle time was 0.863. The large amount of idle time here was due to the bit getting fast in the rock several times, due to the rock's seamy nature. James A. Hart Co., Columbia, N. J. Sec. 7 of the D. L. & W. cut-off has been contracted for by Smith, McCormick & Co., who have sublet part of their work to James A. Hart Co. of New York. Smith, McCormick & Co. are doing the bridge work over the Delaware, while Hart Co. have the grading work. At the present time ^ there are 14 drills at work, operated by steam furnished by two boilers of 125 B.H.P. each. Each boiler takes care of 7 drills, and it has been found by experience that the addition of one more drill impairs the efficiency of the other 7. The drills employed are the Ingersoll- Sergeant type F24. Material being worked, dolomite, or hard limestone. Drill Data. Ingersoll-Sergeant drill. 3|-inch piston. 6-inch stroke ^ December, 1909. 116 ROCK DRILLING Fig. 6i. — Columbia, N. J. Fig. 62.— Columbia, N. J. DRILLING ON LAND 117 Feed 2^9", but use about 2'6". U chuck. Pressure at boiler, 140 lbs. Strokes, 350 per min. When moved, the drill cylinders and slides are removed from Fig. 63. — Columbia, N. J. their tripods and the cylinders from the slide. In this way two men can shift a drill from one position to another. Bits are very irregular in size, due to breaking, repointing, etc.. Eight changes of steel will drill a 20' hole, 2V change. Starting bits are made of if" material with 3^-" points. Length, Material, Point. Length, Material, Point, Feet. Inches. Inches., Feet. Inches. Inches. Starter If ii 12^ li 2i 5 i-s- 3A 15 li =A 7h x| 3i 17^ li 2f 10 I-k^ 2if 20 li 2A Kind of point +. Five men carry steel back and forth from drills to black- smiths. 118 ROCK DRILLING Tempered till file will not touch. Sharpened by hand with aid of a smoother. No jets used, helper pours water into the hole. Holes 20' deep; diameter 4J" at top. Spaced 7' laterally; 7' longitudinally. Cleaned by means of a bailing device, similar to the one de- scribed on the work of Reiter, Curtis & Hill. (See Fig. 66.) Holes are drilled straight down. Rock is dolomite, a hard limestone, solid, and offering a good face for drilling. Thirty to forty holes shot per blast. Dupont powder used. Sticks ii"X8", ^-lb.,60%. Charge to spring holes, 4 sticks. Regular charge about 100 sticks. Blasting machine used to explode charges. Number of drills at work, 14. Boilers, Godfrey Keel and Howard W. Read. Each 125 B.H.P. at 140 lbs. gauge pressure. Feed pipes are not over 400' long. Steam main from boiler, 2", leads to a T from which separate i" lines are laid for each drill. The flexible connection for each drill from the end of the i" pipe is Mulconroy hose, costing 65 cts. per yard. Job to be finished August, 191 1. Ten hour shift; one shift per day. Following is the drilling force at work on the day of the investigation. STANDARD BASIS OF COSTS 14 drillers at $2.50 = $35.00 2 firemen at $2.00 = $4.00 14 drillers' helpers at 1.75 = 24.50 t pipeman at 2.00 = 2.00 5 nippera at 1.50 = 7.50 i pipeman's helper at 1.50 = 1.50 2 blacksmiths at 3.00 = 6.00 2 " helpers at 1.75 = 3.50 Drilling total.. . $84.00 6powdermen. ... at $2,00 =$12.00 Superintendence. One general foreman and 2 foremen, one for each gang of drillers. Each of these foremen also had DRILLING ON LAND 119 rm kr^r^'@|Hg Hr^niBH Fig. 64. — Steam Boiler. Fig. 65. — Steam Pipes. 120 ROCK DRILLING charge of the blasting work. One timekeeper and one book- keeper attended to the office work. Interest and depreciation on drilling plant, valued at $6560, at 2% per working month = $5.05 per day (i shift). Moving drill from hole to hole and getting started, required Fig. 66. — Bailing Holes. 9.2% of the total observed time, costing 9.2% of the drilling wagesj as above, or 55 cts. per drill per day. Oil, '4 gals, per day (14 drills), or 2.28 pts. per drill per day. Coal, 5 tons ($3.10 to main line plus 10 cts. switching charge plus 75 cts. haul, per ton), 715 lbs. per drill per day. The following figures for performance, oil and repairs were obtained from the office of the contractor and are used with his permission: DRILLING ON LAND 121 DRILL PERFORMANCE Date. Number of Drills. Lineal Feet Drilled. December i, 1908 II 13 14 14 16 12 80 449 522 526 612 ** 2, IQ08 ** ^, IQ08. * ' A. IQ08 " 8, 1Q08 " Q, IQ08 412 3102 5i7 = 38|'per drill day Total Average Fig. 67.— Blowing Out Holes. Repairs. Putting 9 drills in shape at the beginning of the present work, $1100. Repairs on 14 drills since that time. 122 ROCK DRILLING 13 months (Oct. i, 1908-Dec. i, 1909), $695.62. These two items are eqmvalent to ;^S cts, per drill per day. On one of the days of the investigation the observed drill did 37^ in 8 hrs., 41 min., 40 sec, and would do 2 V more that day, making 40 lineal feet; 13 other drills at the rate they were working would do 465', making a total of 505' for the 14 drills, or 36' per drill per day of 10 hours. Based on the office data the performance per drill day was ^Sf per drill per day. Combining office data and observed data, we have Working time, 7 days. Drill days, 94. Average number drills, 13-I. Lineal feet per drill per day, ^8^^. Cost of Drilling and Loosening in Dolomite, or Hard Limestone. Based on the above performance and drill data on this job, heretofore given, the following costs per lineal foot drilled and per cubic yard loosened have been deduced: 515J lin. ft. drilled by 13^ drills in i day. Equivalent to 500 lin. ft. drilled by 13 drills in i day. The spacing of the holes being S'XS', the corresponding cubic 500X8X8 yards loosened = =1185. 27 Dynamite, 60%, 1250 lbs. or 750 lbs. nitroglycerine, = 0.633 lb. nitroglycerine per cu.yd. = 1.5 lbs. per lin. ft. DRILLING ON LAND 123 STANDARD BASIS OF COSTS Force. Rate. Amount. Cost per Lin. Feet Cents. Cost per Cu.yd., Cents. 13 drillers 13 drillers' helpers. 5 nippers. 2 blacksmiths 2 blacksmiths' helpers. 2 firemen I pipeman I pipeman's helper. Total labor (drill). Coal, 5 tons Oil (io4gals.permo.,i4drills). Total drilling cost.. 6 powdermen 25 exploders Dynamite, 1250 lbs., 60%. Int. and dep. on drills and boilers at 2% working month $2.50 1-75 3.00 r.75 2.00 2.00 1.50 3-50 0.30 0.03 '32.50 22.75 %5.25 7-5° 6.00 3.50 17.00 4. 00 4. 00 2.00 1-50 3-5° 11.05 3-40 0.80 0.70 $79- 75 17 I 50 20 18.70 12 00 $98.45 12.00 75 0.75 150 00 150.00 $261. 20 5-05 15-95 3-74 19.69 2.40 ^.15 30. Oo 52.24 1. 01 $266. 25 53-25 4.66 1.43 0-34 o. 29 6, 72 1.58 8.30 1. 01 0,06 12. 70 22, 07 0-43 22.50 In the foregoing tabulation of costs, no account has been taken of overhead charges, superintendence, repairs, interest, depreciation, storage, organization, or preparatory charges, charity, accidents, legal, medical expenses, etc. Lineal feet drilled, 37^. Rock, dolomite, hard limestone. Condition, solid. 124 ROCK DRILLING TIME STUDY No. of Obs. Min. Min. Sec, Mean. Min. Sec, Max. Min. Sec, Time. Min. Sec. Consumed Time. Per Cent Total Time. Drill cutting Raising drill Loosening chuck Removing bit Getting bailer Bailing hole Putting bit in hole Inserting bit in chuck . . Tightening chuck Getting started 15 15 15 15 12 12 14 14 14 14 Cycle totals Mucking out Shifting drill and getting started Miscellaneous delays . . . Total II 00 00 00 00 00 00 GO 00 GO 13 ^S 22 00 00 00 00 I GO GO GO GO 40 I OG OG OG 24 07 05 40 2G OG 40 35 10 35 40 15 340 40 11 30 2 45 8 45 3- 55 12 05 4 45 4 45 3 55 I 40 26 52 51 GO 394 45 61 GO 48 15 17 40 521 40 65.4 2.2 o-S 1-7 G.8 ^•3 G.9 G.9 0.7 ^•3 75-7 II. 7 9.2 3-4 IGO.G ±. The cutting speed was o.ii' per min. 2. Ratio of cutting time to total time was 0.654. 3. Ratio of idle time to cycle time was 0.321; mucking out, shifting drills from one hole to another and miscellaneous delays being called idle time. CHAPTER VI DRILLING ON 'LKHT)— Continued Brownell Improvement Co., Thornton, 111. The product of this company is crushed stone. The quan*}'- is composed of hardj crystalline limestone, fissured on top, very solid on bottom. The process of preparing this stone for market consists in loosening, loading and crushing. The loosening is accom- plished by means of drilling and blasting; the loading by two 95-ton Bucyrus shovels, and the crushing by McCully crushers. In front of each shovel are 4 Ingersoll drills, drilling top holes 26' deep, operated by air at 120 lbs. from a single phase compressor, capacity 1200 cu.ft. per min. Top holes are spaced 6 to 6J' longi- tudinally and are laterally 8 to 10' from the unbroken face. In the rear of one of the shovels are 4 drills engaged in drilling '' toe " holes from 10 to 14' in depth. Two toe holes are drilled, one at about 15° and one at 60° with the vertical, the former being 2J' in front of the latter and 6' along the toe. Besides these drills, each shovel has a small one-man drill for quick service in breaking up large rocks that cannot be sledged. The rock is somewhat porous in places and in others as solid as feldspar. The top holes are each charged with 75 lbs. of 60% dynamite in the form of sticks 2>Y'^^" of 4I lbs. This is equivalent to 12' of dynamite per hole. The other 14' of hole is filled and tamped with crushed stone. Based on the same ratio of depth to dynamite toe holes would be charged with 35 lbs. of 60% dynamite. The shovels load into 5-yd. cars weighing about 4 tons and costing $150. Trains are made up of 10 of these cars and 35-ton dinkeys haul the cars from shovel to crusher. The product of the McCully No. 10 crusher is carried by an iS" conveyor upward to a ^Y' screen near the roof, thence into a bin. The contents of this bin are crushed finer by 3 smaller McCully crushers. 125 126 ROCK DRILLING Fig. 68. — Drilling Toe Holes — Thornton Quarry. Fig. 69. — Loading Toe Holes — Thornton Quarry. DRILLING ON LAND 127 Belt conveyors, smaller machines, bins and screens form the rest of the crushing plant. Altogether there are 9 crushers in the plant and 7 different sizes of stone are produced and marketed. Drill Data. IngersoU drills, 13 D.F.A. Feed, 2'. U chuck. 325 strokes per minute. Drills lifted from one hole to another by two men. Holes two kinds, top and toe. Diameter of starting bits, top 51%, toe 4-Jr''. Diameter of finishing bits, top 4^}, toe 3I". Shape of bit, top z, toe +. Steel, 2' to 26', in 2' sections. Octagonal section, top if", toe if. Top bits handled by two men with hooks. Toe bits handled by one man with hooks. Bits tempered very hard with fish oil. Sharpened by hand. Depth of top holes, 26', toe holes 10 to 14'. Longitudinal spacing of each, 6 to dV . Lateral spacing, top 8 to 10', back from unbroken face. Toe holes, a 15° hole 2 V in front of a 60°. Cleaned by hand pump. Toe holes, front row, make 15° angle with vertical. Rear row 60° with vertical. Rock is a crystalline limestone, fissured at top, porous in some places and in others solid as feldspar. Holes shot per blast, top 60, toe 75. Powder, forcite. Sticks, 2ylY^'^"\ 4ilbs. Charge, 75 lbs. Fulminate of mercury battery used. Blasting gang, 3 loaders, 6 tampers, foreman and assistant foreman. Fourteen drills (2 drills used infrequently). Single-phase compressor. Capacity of compressor 1200 cu.ft. per min. 12S ROCK DRILLING Fig. 70. — Drilling Top Holes — Thornton Quarry. Fig. 71. — Drilling Top Holes — Thornton Quarry. DRILLING ON LAND 129 Air pressure at tank, 120 lbs. Length of feed pipe, i5oo\ Diameter of feed pipe, 4". Branch pipes, 2" in diameter. Repairs and Drill Supplies (taken from office record with per- mission of superintendent). 14 drills, January i, 1909, to September 30, 1909, 9 months. $3058.47 during 3276 drill days. Repairs, etc., per drill day, 93 cts. Interest and depreciation on drilling plant estimated at $7700 at 2% per working month = $5.90 per day. Drill performance, taken from office record, 7 days, 11 drills, 2258 lin.ft., or 29.3' per drill day. Moving drill from hole to hole and getting started required 4.6% of the total time, costing 4.6% of drilling wages, or 28 cts. per drill per day. Length of shift, 10 hrs. One shift per day. Drillers work in pairs and are paid by the foot, 6 cts. per ft. for first 30' of small holes, and 7 cts. a ft. for all over 30'. Large holes, 8 cts. a ft. A crew consists of two drillers and one helper, the helper receiving 17 J cts. an hour. Stone sells for from 75 cts. to $1.25 per cu.yd. Work of smith is to sharpen drills and make odd repairs. Coal estimated at 6 tons per day for 12 drills =1000 lbs. per drill per day. Coal cost $1.70 delivered. Drills. On work, 10, 13 D.F.A.'s. 2, F 24's. 2, B 32's. Oil at compressor, estimated at 3 gals, per day, or 2 pts. per drill per day. The following costs per lineal foot drilled and per cubic yard loosened are based on an average performance of 2258 lin.ft. in 7 days, 11 drills at work. The cubic yards corresponding have been deduced as follows: Top holes 26' in depth, beinc^ 130 ROCK DRILLING C VJirr r i— — — — — ^ •v^- V .^ Fig. 72. — Drilling Top Holes — Thornton Quarry. Fig. 73. — Loading Top Holes — Thornton Quarry. DRILLING ON LAND 131 placed from 8 to lo' back from the unbroken face, it is assumed that the rock will break back 14' from the face. Toe holes average 12' in depth and both toe holes are spaced about 6' longitudinally. Therefore for each toe hole and top hole, or 26 + 12 = 38 lin.ft. of drilling, the cubic yards loosened, will be, = 81 cu.yds., and for 2258 lin.ft. drilled, 4820 cu.yds. 27 would be loosened. Dynamite being 75 lbs. per top hole and 35 lbs. per toe hole for each 38' of drilling, there are used no lbs. of 60%. For 2258 lin.ft. 6540 lbs. will be used. On the daily basis the above performance reduces to the fol- lowing: Lineal feet 322^, cu.yds. 688^, d}Tiamite 934 lbs. of 60%, or 560.4 lbs. of nitroglycerine = 0.8 1 5 lb. per cu.yd. loosened. No account has been taken of contractor's overhead charges, superintendence, organization or preparatory, legal, medical, accidents, repairs, charities, etc. Lineal feet, 322^; cubic yards, 688J; 60% dynamite, 934 lbs.; drills, 11; material, crystalline limestone. A cycle for each 2' of hole is here made up of the two items of drill working and changing steel. The time of " drill working " TIME STUDY Lineal feet drilled, 34. Total working time, 5 hrs. 32 min. 50 sees. Kind of rock, hard limestone. No. of Obs. Min. Min. Sec. Mean. Min. Sec. Max. Min. Sec. Time. Min. Sec. Consumed Time, Per Cent of Total Drill working 17 15 6 I 43 3S 13 3 10 56 18 9 00 30 223 59 59 08 67.5 17.7 Changing steels Cycle totals 8 18 17 06 27 30 283 34 07 30 13 85.2 4.6 10. 2 Moving drill over to new position and setting up. Miscellaneous delays 2 9 Total 33^ 50 100. Cutting speed in feet per cutting minute, 0.152. cutting time Ratio . , , ,. =0.675. Ratio total time idle time cycle time =0.174. 132 ROCK DRILLING STANDARD BASIS OF COSTS Force. II drillers II driller's helpers. 2 smiths 2 smith's helpers. 3 nippers I engineer. I fireman.. I pipeman. Total labor drilling Coal, 6 tons Oil at I qt. per drill, per gal Oil at 3 gal. compressor, per gal.. . Total drilling 3 powdermen 6 tampers 934 lbs. of 6o% dynamite. 2o exploders Total drilling and blasting Int. and dep. on ii drills, comp. and boiler capacity, estimated at $y 700, at 2% per working month Total. Rate. $2.50 1-75 3.00 1-75 1.50 3.00 2.00 S3 -50 0.30 0.30 2.00 1-50 o. 12 0.03 Amount. $27.50 19-25 6.00 3-50 4-5° 3.00 2.00 $46-75 14.00 5 -00 2.00 21.00 0.825 0.90 6.00 9.00 II 2 . 08 o. 60 ^7-75 22.72 $90.47 15.00 112.68 te2I». 15 5-90 3S224.O5 Cost per Lin. Foot Cents. 14.49 4-34 1-55 0.62 7-05 28.05 4.66 67.71 1.80 Cost per Cu.yd., Cents. 6.80 2.03 0-73 0.29 9-85 3-30 13-15 16.36 69-51 31.69 0.86 32.55 is the actual time of cutting, i.e., the time between the turning on of the air to start the drill and the time of turning off the air when the section of the hole is finished. The time " changing steel " is from the time when the air is shut off and the drill stopped until the air is turned on and the drill begins cutting. This *' changing steel " includes the following items: Screwing up, loosening chuck, removing steel, bailing, inserting steel, and tightening chuck. Duluth Crushed Stone Co., Duluth, Minn. The Duluth Crushed Stone Company operates a quarry at the end of 57th Avenue West, in West Duluth. The rock is a hard bastard DRILLING ON LAND L33 granite in its natural bed in the side of the rock hill that rises from Duluth Harbor and follows the shore of Lake Superior east, and the St. Louis River west from Duluth. In many places the rock outcrops, and above the present quarry, rock is to be seen on the surface where no stripping will be necessary. The maximum depth of stripping is in no place over 3', except where faults occur, and the average depth is not more than i'. The condition of the rock varies greatly in different parts of the quarry, and also in the same part of the quarry as the face is worked back. In some places the rock is absolutely solid without a check or irregularity in structure other than is ordinarily found in this kind of rock, while elsewhere it will be badly cracked and full of seams, with its entire structure irregular and badly broken up. This latter condition exists especially in the west end of the quarry. The product of the quarry is crushed stone in sizes from dust to 2-y' and rubble of any size as ordered. The structure of the rock does not permit of its being taken out for dimen- sion stone or of its being cut easily, although it could without doubt be worked into regular shapes if occasion arose. The stone company does not undertake to furnish such stone, however, and so makes no effort to quarry it. Beside its regular output of crushed stone and crusher dust the quarry is at present filling two contracts for rubble. One of these is with the Great Northern Railroad, and calls for quarry run rubble up to 6" size. This material is loaded into skips by hand and is raised by a locomotive crane and dumped into gondolas. The other contract is for furnishing quany run rubble up to 10 tons size, the number and amount of blocks of the latter size being regulated by the demand of the pur- chasers of the stone. This stone is beuig used in the construc- tion of a breakwater at the Superior Entry of the Duluth-Superior Harbor, and as the portion now being constructed is in shallow water the amount of lo-ton stones being shipped is about 50% of the total amount. The heavy stones are used for paving the surface of the breakwater. 134 ROCK DRILLING At the present time the rock in the quarry is running so unevenly and is so seamy and broken up in its bed that it is extremely difficult to obtain the desired amount of lo-ton stones. For the rest of this contract nothing as small as a two-man stone is shipped, but only large blocks which are handled by the r7"n N.g. Track ^I O SJc^j ^^ N.g. TiackH-a Fig. 74. — Duluth Crushed Stone Co., Duluth, Minn. Tracks. Layout of Quarry and crane. All this material is loaded on cars by the crane, being chained and lifted. All material which is thrown down from the face of the quarry which is not used for the above contracts is sent to the crusher. The crusher takes 12" rock, and anything larger than that is sledged to that size, and if too large to sledge is plug- holed with a hammer drill and shot. DRILLING ON LAND . 135 The loading track for the crusher runs along the slope at the foot of the quarry face. The cleaning gang throws the stones down along this track and the loading gang throws them into the cars. The tops of these cars are about 30" above the track, so that they can be loaded very easily. About 25 cars are placed on the loading track at a time and when these are loaded they are let down the track to the crusher in sections of three cars each, with one man handling a section. The loading track is on a slight grade down to the crusher, the grade being so slight that it is not visible to the eye. Each car is provided with a brake, and one of the loading gang goes with the cars to brake them. While 6 or 8 men are thus engaged the rest of the men are busy piling up rock along the track for loading. The cars run to the crusher where they are dumped by an automatic tipple and then run back over a crossover to another track out of the way of the next load. As soon as all the cars have cleared the crossover (marked No. 2 on map, p. 134), they are drawn in sections of 3 or 4 cars from the narrow gauge track No. 2 to the main load- ing track by horses, and are returned to the quarry for loading. Two horses are used for this purpose, each horse drawing 3 to 4 cars. As soon as the cars are loaded they are again let down to the crusher. In loading with the locomotive crane two methods are used. As before stated, the material for the railroad company is loaded into skips and raised by the crane and dumped into gondolas. The heavy stone of the breakwater is all loaded by chaining. The tracks are so arranged that fiat cars can be placed beside the crane and the blocks swung onto the cars. The crane was made by the Industrial Works, Bay City, Mich., and has a capacity of 5 tons at ^^' radius and 17 tons at 12' radius without outriggers. With the outriggers it holds 7 tons at 35' and 30 tons at 12' radius. The drilling in the quarry is not very regular. There are generally at least two drills working. One may be working above the quarry and one below on the face, or both naay be above. One is kept above all the time, and sometimes an extra one is 136 ROCK DRILLING put in on the face, making two there. The average drill per- formance is about 75' per day when drilling above the quarry, where 24' holes are drilled. On the day on which the time study was made No. i drill did a total of 70'. On the previous day 14' were drilled before the time study began. No. 2 drill was- working in the bottom of a fault, and was only doing 22' holes. The total was 66', but i^} hrs. were used in getting the drill to the top from the bottom of the quarry and in setting up after cleaning out the fault. Each helper acted as his own nipper. The plug-hole drilling in the quarry is done with three small hammer drills, one Ingersoll-Rand and two Murphy. There was no opportunity to observe the working of these drills, but the foreman said they never did less than 80' a day, and generally did about 100'. The holes are from 8 to 12" deep. These hammer drills are fed from i" lines run over the face of the quarry from the 1" main above. These lines are often as long as 130', and the air hose is sometimes 20', making a very long line. Drill Data. Rand " Little Giant " drills, 3^" piston. Stroke, 6f (the piston could be moved 7f")- Feed, 2' (ti steels were used in drilling 24'), U chuck. Strokes, 300 plus, per min. When necessary to move from hole to hole the drill was swung to a horizontal position on the tripod, the starting steel was placed in the chuck, the feed screw raised to its extreme position, and then drill and tripod, without weights, were raised on the shoulders of driller and helper and carried. Bits, 2-y starting; i'' finishing. Points, + for first 10 bits, full for finishing. Steels, 2' b" to 24' 8". Steel sections, first four, i^' hexagon; next four, i^' hexagon; last three, i" hexagon, jumped at ends for chuck. Handled by hand; helper acts as nipper. Temper medium for all but last three steels, which were hard. DRILLING ON LAND 137 Hand sharpening. No jets used. Holes, 24' maximum. Holes, 2-|" at top. Longitudinal spacing, 4 to 6'; not regular, but depending upon lay of rock. Lateral spacing, ist row back from 6 to 15' from edge of face; 2d row from 7 to 10' from first. This all depended upon the rock. Cleaned by hand pump. Holes vertical. Rock, hard bastard granite. Condition, natural bed under 12 to 36" stripping; in som.e places soHd and in others seamy and slightly checked. Holes shot, depends entirely upon work and kind of stone wanted. ^tna Powder Co.'s dynamite. 1X6" sticks, about J lb. From 4 to 6 sticks of 75% put in bottom and 10 to 15 sticks '60% put on top of those. Lion brand double strength exploder. Blasting gang, i powderman and 2 helpers. This is not a regular gang, as shots are irregular and gang is needed only before a shot. Number of drills, 3 maximum, only 2 ordinarily working. Pressure 93 lbs. (gauge). Compressor, Rand " Imperial," type 10. Compressor capacity, 537 cu.ft. free air per min. Seventy-eight pounds pressure at tank. Feed line, 3" pipe leads from the compressor to the air reservoir, a distance of about 10'. The tank is 10X4'. From this runs a 2" main about 900' along the hillside to the top of the quarry, and along the top about 20 to 30' from the edge; i" branches run from this at intervals of 16 to 30'. If drills are working on top of the quaiTy these i" branches are about 16" long, and the air hose fastens to them direct; if working in the quarry the i" leads may be 130' long, reaching down over the face, which is 90' high. 138 ROCK DRILLING Size: Quarry has a face 90' high and about 400' long. The entire face is 500' long, but earth slopes are left at the ends. Shifts, 10 hrs. One drill shift; 2 loading with crane. Force. Standard Wages per day. Force. Standard Wages per day. 2 drillers - $2. 50 1-75 2. 00 2.00 3.00 2. 00 I powderman loading plugs 8 loading with crane I smith $2.00 2 drillers' helpers 2. 2t^ 4 hammer drillers 3-00 1-75 1-5° 36 cleaning face and loading. I smith's helper 2 drivers I fireman on crane, 2 shifts. Interest and depreciation on the two working piston drills and necessary compressor and boiler capacity valued at $1200, at 2% per working month =-$0.92 per day (2 drills). Coal, 1000 lbs. per drill per day. Oil, 3 pts. per drill per day. General Notes. The layout of the air system has been given in the list of drill data, but a word more may be said about the compressor. This is a Rand Drill Co. Imperial type 10, duplex steam and compound air. The steam cylinders are 10X14 and the air 16X14 and 10X14. The speed is 144 R.P.M. The rated capacity is 537 cu.ft. free air per minute. The pressure at the compressor is 78 lbs. and the steam pressure is 105 lbs. (gauge). The blasting of plug holes is done at noon and after six o'clock at night. The blasting of the rock from the top is done as needed. In one blast one evening 36 holes were shot. These holes were loaded as given in the drill data and exploded "n the usual way. The blast was for the purpose of getting material for the breakwater contract, but owing to the seamy condition of the rock at that particular point in the quarry but few large blocks were thrown down, the foreman saying that there were only five in sight which would be in the ten-ton class. DRILLING ON LAND 139 When a blast is made from the top, heavy 12 X12" timbers are laid along each rail on the quarry side to prevent the rails being broken and twisted by the falling rock. Several sections of the crane track are also removed and carried some distance. The crane lifts these sections and moves back the desired distance with them. It also moves narrow gauge track No. i if the blast is to be in the middle of the quarry. The crane and the loading gang on the heavy material were working a night shift, while only one shift was worked in the rest of the quarry. This was necessary, because the contrac- tors on the breakwater worked at night and in two shifts could use more than the quarry could get out in one. With regard to the time study on the two drills working above the quarry, No. 2 drill had been working on the face of the quarry previous to that day. It took three men, the driller, his helper, and one extra man i hr. 5 min. to carry the drill and steels from the quarry to the top. The longer steels were already at the top, not having been required below. The work for this drill was directly in line of a large fissure which was filled with earth and disintegrated rock to the depth of from 2 to 3'. The holes had to be mucked and the drill set up. This required 30 min. on the part of the driller and helper. They finally started their drill at 8:40. Drill No. i started a new hole at the same time, so observations were made on that drill from the start of the new hole. This drill had finished 14' of the previous day's hole and moved and set up in i hr. 40 min. No. 2 drill lost 31I min. waiting for the drill helper. Each helper acted as his own nipper, and when this driller finished a steel before his helper returned he would wait, making no effort to remove the steel or pump the hole. When drilling his first hole the driller on No. 2 drill let his helper run the drill and he mucked the next hole. During the second hole he did not do this, and in consequence time had to be taken off for mucking. The third hole was finished at 5 : 27, and the driller spent the rest of the day mucking, but he was really " soldiering," so as not to start a new hole before quitting time. 140 ROCK DRILLING No. I drill had much trouble with its first hole. The steel stuck constantly and time and again the tripod had to be loosened to allow the steel to find an easy position in the hole. The 6' steel was stuck fast for 5 min., and all efforts to move it were useless until a long-handled Stilson wrench was put on and hammered with a heavy stone hammer. Cast iron was used in this hole and in the others as well. At one time when the helper was away the driller on No. i took out the steel and pumped his hole. It took 3 mins. to do this alone, against an average of 2.19 mins. for two men. This was an 8' hole; it would have been almost impossible for one man to pump the deep holes. In working the quarry a large amount of loose rock, the smaller sizes of which are about one-man size, has been left on the bottom between the standard gauge loading track and narrow gauge track No. 3 (see map, p. 134). This was done so that if a blast covered the main narrow gauge track No. i, the crusher could still be supplied by the small cars loaded on narrow gauge track No. 3. There is beside the 12" crusher a small crusher which crushes the pieces rejected by the 2 J'' screen at the large crusher. This small crusher is also provided with a tipple and cars from the quarry can be dumped there. This is seldom done, as even when the cars carry only the sweepings from the quarry they are dumped into the large crusher with the rest. Cost of Drilling. Based on the foregoing performance of the two drills observed, namely, 70 and 66' respectively for the day of 10 hrs., the following costs have been deduced: No account has been taken of contractor's overhead charges, superintendence, storage, repairs, preparatory costs, insurance, charity, accidents, legal, medical expense, etc. DRILLING ON LAND 141 Lineal feet drilled, 136. Kind of material, bastard granite. Number of drills, 2. 7^ lbs. of 75% and 18^ lbs. of 60% dynamite = 16.7 lbs. of nitroglycerin, or about 0.123 ^^^ P^^ lineal foot of hole. I Standard Basis of Costs. Rate. Wages. Cost per Lin. Foot, Drilled. Cents. 2 drill runners 2 drill runners' helpers. 2/6 engineer at compressor. 2/6 firemen. 2/6 blacksmith , 2/6 blacksmith's helper. 4 men i^^ hrs (carrying machine up to top). Total drill labor. I ton coal Oil 6 pts., per gallon. . . Total drilling. I powderman 26 lbs. of dynamite- Total. Int. and dep. on the 2 piston drills at 2% per working mo. and necessary compressor and boiler capacity = $0.92 per day or 0.67 cts. oer ft. drilled Total. 5l>2.so 1-75 3.00 2.00 3.00 1-75 0.17^ $5.00 3-50 1. 00 0.66 $8.50 1.66 1.58 0. 76 1. 00 0.58 0. 76 3-5° 0.30 3-50 o. 22 $12.50 3-72 3.12 i5i6. 22 3.12 !i'2i.34 6.2s 1. 16 0.56 9.19 2.73 11.92 1.47 2. 29 15.68 0.67 16-35 142 ROCK DRILLING DRILL No. 1 Material, bastard granite. Lineal feet, 56. Total time of observation, 8 hrs. 13 min. 10 sec. No. of Obs. Min. Min. Sec. Mean. Min. Sec. Max. Min. Sec. Consumed Time. Min. Sec. Consumed Time. Per Cent Total Time. Actual cutting 26 26 19 23 4 20 3S 1 05 50 12 14 1 20 2 19 I 21 25 20 I SS 4 35 I 55 318 45 34 30 44 55 31 00 64.6 7.0 91 6-3 Taking steel out and get- ting pump in Pumping and cleaning Putting steel in Cycle totals . - - 6 50 17 14 33 45 429 10 30 05 20 40 13 15 87.0 6.1 4.2 2.7 Setting up and adjusting. . Drill stuck or putting in cast iron Miscellaneous delays Muckine Total 493 10 100 Cutting speed in feet per cutting minute o - 1 75 Ratio cutting time to total time o. 646 Ratio idle time to cycle time o. 149 DRILL No. 2 Lineal feet, 66. Total time of observation, 8 hrs. 14 min. 30 sec. No. oE Obs. Min. Min. Sec. Mean. Min. Sec. Max. Min. Sec. Consumed Time. Min. Se.?. Consumed Time. Per Cent Total Time. Actual cutting 30 30 26 27 4 20 45 1 00 40 7 I 2 I 58 31 24 07 16 3 3 I 15 00 00 50 239 35 45 35 62 30 29 45 48.5 9.2 12. 6 6.0 Taking steel out and get- ting pump in Pumping and cleaning. . . Putting steel in Cycle totals 6 45 13 00 24 05 377 25 41 05 31 45 44 15 76.3 8.3 Setting up and adjusting, . Drill stuck or putting in cast iron Miscellaneous delays 6.4 9.0 Muckino" Total 494 30 100 Cutting speed in feet per cutting minute o. 275 Ratio cutting time to total time o. 485 Ratio idle time to cycle time 0.310 CHAPTER VII DRILLING ON 'LAN'D— Continued Contract No. 23 on New York Water Supply, Catskill Aqueduct. Contract No. 25 on the Catskill Aqueduct of the New York water supply is being executed by Blakeslee & Sons, of New Haven, Conn. This contract extends from the lower end of contract No. 24, just below the Croton Lake Siphon, to Millwood. Beside the usual cut-and-cover aqueduct the con- tract includes the Croton Tunnel about 3000' long, and the shorter Chadcayne Tunnel. Both of these are grade tunnels, and there are no siphons or pressure tunnels on the contract. The work in the Croton Tunnel is being carried on in three shifts of 8 hours each. A f heading is being driven the full width of the required cut, and is being followed at a distance of about 50' by the bench, which completes the full required section. This required section has a height of 19' 3'^ on the center line. This provides for a 17' clear headroom in the completed concrete section and a 5'' concrete base, 9" cap, which must be free from rock, and 13" into which rock may project to some extent. The total width of the excavation is 16' — 4" at a point 6' — io|'^ from the finished bottom, and this 16'— 4" provides for 13' — 4'' clear concrete tube, 5'' clear concrete on each side, and 13" of concrete on each side into which rock may project. The rock being excavated is bastard granite of very even quality. There are few cracks and seams and the rock is very free from water. So little water comes in that about half the time it is necessary to carry \vater into the heading for the pur- pose of cleaning the drill holes. When this is necessary, a man carries the water in a pail and pours it into a tub which is placed between the drill columns. 143 144 ROCK DRILLING The drilling in the heading is done with four Ingersoll-Rand drills, type E 24, mounted on two drill columns. In the case observed these columns were set 30'' and 42''' to the left and right of the center line respectively. The columns were 8' long and 5^^ in diameter. They were rigged with double screws. The upper drill on the column was moimted on a 22'" arm, and the lower drill was on a 36" arm. All arms were sup- ported by safety clamps. When the highest holes in the heading were being drilled it was necessary to have some elevation from which the men could work. This was provided by running two heavy planks from the rough face of the heading to the muck pile which had been thrown up before the columns could be set. These planks were run between the columns, as the two upper drills were rigged on the inside of the columns. The drilling of the heading was on the following system (Fig. 75) : Three sets of holes were drilled, 6 "cut" holes, 6 '* inner-round '^ holes, and 10 " outside-round " holes, making 22 holes in all. The outside-round holes are driven on the arc of a circle 14' in diameter, and are spaced at almost equal distances from each other, about 30'' apart. The bottom holes of each series are at the same elevation, and run as close to the bottom of the heading as possible. The first, second and third holes on this bottom row are spaced about 30'' apart, while the distance between the lower cut holes is about 6'. The second cut holes from the bottom are closer together and the distance between the top cut holes is about 2'. The two cut holes on the same level converge at the lower end, sometimes meeting. As a general thing it was attempted to have the end of one slightly above the end of the other. The bottom cut holes pointed down shghtly while the others were nearly horizontal, the top holes having a slight downward pitch. The inside-round holes converge very slightly toward their lower end and are nearly horizontal. The outside-round holes slope up and away from the center of the tunnel. The upper holes are drilled dry, but all the others are wet. They are DRILLING ON LAND 145 watered by the driller or helper throwing water into them. This would, of course, be useless in the holes that pitch up. All holes are drilled from one setting of the drill columns. The upper drills do five holes each round and the lower drills do six. A round requires from 6 to 8 hrs. to drill. As soon as a drill finishes its last hole on a round, it is taken from the column arm, the arm is removed from the column, and if the other drill on that column has also finished its holes the Arrangement of Holes in Heading ' (£) (£) {■: >i ^ 1 S - -^ J — V; r. S\ r 7\ r^ rT> (1 \ 2- A r 1^1 ty 'M) © '^ ?, ) oL. ^ J fi- 1 J -?— M. ,o_L '^1:: ^ — — — — — — - — — - — - — — ll' — — — — — ■ ' Holes marked _a are "cut" holes " V b_ " "inside-round" holes )» n _c. *) "outside-round" » Fig. 75. column is taken down and the whole outfit is carried back over the bench and loaded on a flat car on the muck car track, to be carried out of the tunnel before blasting is done. The holes are all loaded before any of them are shot. The cut holes have from 8 to lo sticks of 6o% dynamite, and the inside- and outside-round holes have the same amount of 40%. When all are loaded the cut holes are connected and shot, each hole having an exploder. After the cut holes are shot the inner- roiond holes are connected, and if any of the cut holes are not 146 ROCK DRILLING totally shot what remains of them is loaded full and connected with the leads from the cut holes. After this second shot the outside cut holes are shot together with the ends of .iie inside cut holes which are left undestroyed. The leads to the blasting box .are about 500' long and the box is located just inside the portal. The current for exploding the blasts is taken from the mains which supply current to the tunnel and to the rest of this portion of the work. There are no regular powdermen, the drillers, helpers and nippers all helping in the loading, blasting and consequent muck- ing. The time taken in loading the 22 holes is about 30 min. and for blasting i hr. The mucking then necessary before the drills and columns can be set up takes 3 hrs. on an average. The men so engaged comprise 4 drillers, 4 helpers, and 2 nippers, with i foreman for overseeing the work. The deduced costs of blasting, powder, and mucking which follow have been based upon the above. The standard cost of drilling has been based upon the observed performance of 60' in 16 and a fraction drill hours, or the equivalent of 2 drill days of 8 hrs. each. Lineal feet drilled, 176. Cubic yards blasted, 22.8. Dynamite per Blast. Dyna- mite, lbs. Nitro- glycerin, "lbs. 6 cut holes at g sticks of 60% at tr lb 27 27 45 16.2 10.8 18.0 6 inside round at 9 sticks of 40% at i lb 10 outside rounds at 9 sticks of 40% at ^ lb Total 99 45 -o Nitroglycerin per lineal foot drilled, 0.255 '^* Nitroglycerin per cubic yard blasted, 1.97 lbs. Drill Data: Type of drill, Ingersoll-Rand, E 24; on heading. Size of piston, 3J''. Length of stroke, t\" . Length of feed, 24". 8 drills;, 4 on bench, 4 DRILLING ON LAND 147 U chuck. Drill moved by hand. Bits, starting 2f", finishing, 2 J". Point shape, + . Length of steel, 2' to 10' by 2' increments. Shank section, hexagonal. Bit handled by hand by nipper. Temper very hard. Sharpened by smith by hand. No jets used. Depth of holes, S\ For spacing of holes, etc., see diagram, page 145. Holes cleaned by throwing in water and then bailing out with bailer. Rock, bastard granite. Condition of rock, good. Shooting of holes, 6 cut holes shot first, then 6 inside rounds, then, lastly, the 10 outside rounds. In each case all holes not fully shot are reloaded and shot on succeeding blast. Dynamite used, 60% and 40% Forcite. Cut holes, 9 sticks at \ lb. of 60%, others same amount of 40%. The crew working in the heading is composed of 4 drillers, 4 helpers, 2 nippers, and a foreman. These men drill the 22 holes, then blast them and then muck out to get their drills going again. The four drills are set up on two columns as heretofore men- tioned. Compressors, 2 Ingersoll-Rand, type 10. Interest and depreciation on 8 drills (4 on bench and 4 on heading) and on compressors and boilers at $7315, at 2% per working month = $5.63 per day = $1.90 per shift = 24 cts. per drill per shift. Superintendence: One general superintendent, i foreman per shift in heading and i assistant foreman per shift on bench. Moving drills from hole to hole, setting up on column, getting started (in heading), consumed 30% of the total observed time, costing 30% of drilling wages, or $1.72 per drill per shift. us ROCK DRILLING Based on the observed performance of 60 lin.ft. in 16 and a fraction drill hours, the following costs in tunnel heading per lineal foot drilled have been deduced. To deduce the same items of cost per cubic yard loosened, it is necessary to know how many lineal feet have been drilled to loosen i cu.yd. This is done by dividing the lineal feet drilled for each shooting, or 22X8 or 176 by the cubic contents of the semicylinder, 7' radius . , , 3.1416X7X7X8 and 8 deep, or — — — or 22.8 cu.vds. The desired ^ 2X27 ratio of lineal feet to cubic yards loosened is then 176 divided by 22.8 or 7.72. Therefore by multiplying the costs per lineal foot by 7.72, we can get the corresponding costs per cubic yard loosened. DRILLING COSTS Drill hours, 16. Lineal feet, 60. i cu.yd. = 7.72 lin.ft. Bastard granite. Force. 2 drillers - 2 drillers' helpers . I blacksmith i blacksmith's helper. I nipper. I engineer. I fireman.. Total drilling labor. I ton coal 6 pints oil Total drilling. Costs on Standard Basis. Rate. $ 2 . 00 1-75 3.00 1-75 1-5° 3.00 2.00 3-50 0.30 gal. Amount. $4.00 3- SO 0-75 0.44 1-50 0.75 o. 50 3-S° o. 22 $7-50 .69 1-25 11.44 3-72 $15.16 Costs per Lin. Foot Drilled, Cents. 12.50 19. oS 6. 20 25 . 28 Costs per Cubic Yard Loosened, Cents. 96.5 34.6 16. 2 147.3 48. 195-3 The following costs of dynamite, blasting and mucking as afore- said are based on all hands (4 drill crews and 2 nippers) working i^ hrs. at loading and blasting for each shot of 22 holes, or 176 DRILLING ON LAND 149 lin.ft., and the same crew working 3 hrs. at the consequent mucking : Blasting (labor i^ hrs.). Dynamite, 99 lbs. at 12 cts.. Mucking (labor 3 hrs.) Interest and depreciation at 2% per working month on $73 15 (2 drills) Amount. 11.88 6. 72 0.56 Cost per Lin. Foot Drilled. Cents. I. 91 Cts. 6.74 '' 3.82 " Cost per Cubic Yard, Cents. 14.75 Cts. 52.10 '' 29.50 " 0.003 " 0.023 " In the above items of costs no account has been taken of superintendence or overhead charges, repairs, organization or preparatory charges, storage, insurance, accidents, charities, legal, medical expenses, etc. TIME STUDY Tunnel work. Material, bastard granite. Lineal feet, 60. Total time, 16 hr. 27 min. 30 sec. No. of Obs. Min. Min. Sec. Mean. Min. Sec. Max. Min. Sec. Time. Min. Sec. Consumed Time, Per Cent Total Time. Drill cuttino- 30 25 6 15 I 50 12 04 3 49 17 45 5 40 362 15 95 20 36.7 9.6 ChanKiiiff steel Cycle totals 8 05 15 S3 93 10 14 30 23 25 457 35 79 25 186 20 29 00 235 10 46.3 S.o 18.9 3-0 23.8 Moving on columns and getting started Setting up columns and getting started 4 2 2 Dismantling columns Miscellaneous delays Totals 987 30 100. Average cutting speed in feet per cutting minute, 0.165. cutting time Ratio ^ — , ■ =0.^67. total time ^ ' idle time Ratio 1 : — = 1.16. cycle time The process of setting up a drill on a column and getting the drill started may be conveniently divided into the follow- ing items with average values for each : 150 ROCK DRILLING M. S. Carrying and setting base 17 52 Setting column on base 3 37 Putting in blocking at top , . , . 16 38 Preparing and setting jacks 10 25 Placing and adjusting arm 10 13 Placing and adjusting drill on arm 5 35 Attaching hose 11 00 Getting started 17 50 Cycle total 93 10 = 1 hr. ^;^ m. 10 s. The process of dismantling may be divided up as follows with average values : M. s. Removing drill from arm 6 07 Removing arm from column i 43 Taking down column 4 40 Taking out base. 2 00 Cyc'e total 14 30 General Notes. The columns used are 6" in diameter. The two upper arms are on the inside and the drills on these arms drill the top outer-round holes. The two lower arms are on the outside and start on the second cut holes from the bottom. When a hole has been finished it is necessary to shift the drill on the arm, or the arm on the column, or to do both. When one shift alone is necessary a fair value for time is 7 min.; when a double shift is necessary a fair value is ^^ min. When it is necessary to take down columns, etc., a fair value as before itemized for dismantling is 14 min. 30 sec, and for setting up again 93 min. to sec. These times, with the exception of that for dismantling, include the adjusting in new position, getting started, etc. CHAPTER VIII DRILLING ON l.AN'D— Continued Soudan Mine of Oliver Iron Mining Co. at Towar, Minn. The material in this mine is a very hard jasper and quartzite, in some cases being so hard that to drill a hole 4 or 5' in depth from 50 to 85 steels are needed, and holes have to be blasted with powder every 8 to 10" in order that steels may not bind. Steels are sharpened by a drill sharpening machine. Five drills of I" octagonal steel with 2J" points were sharpened in this machine in an average time per drill of 36 seconds. No records of performance are kept in these mines, but an occasional test is made. The following records of tests have been obtained from the office: Type of drill, Ingersoll-Rand, No. 3. Steel, O.H. Air Pressure, 70 lbs. Date. Lineal Feet. Cutting Time. Feet per Min. Material. No. I, March 8, 1908 . .. No. 2, March 8, 1908 . .. No. 3, March 8, 1908 . .. No. 4, March 8. igo8 . .. 107 104^ 76 210^ 214^ 122 122 0.00847 0.00814 0.01055 0.OT038 Jasper Jasper Ouartzite Quartzite Note. In addition No. i cut 5' of soap rock and No. 2 27' of soap rock. On May 22, 1908, the following records were taken for work with Ingersoll-Rand hammer drills : Type drill, Ingersoll-Rand hammer drill. Air pressure, 70 lbs. Material, quartzite. No. Hole. Angle. Lineal Feet. Drill Time. No. Bits. Feet per Min. M. S. I 2 Vert. 80° 4' or 4' ^" II ID 14 40 8 8 0.0364 0.0279 3 4 5 2S° Vert. Vert. 3' 7" 4' 6V' 10 45 11 30 12 38 7 8 S 0.0332 "■0357 0.0359 151 152 ROCK DRILLING In the Pioneer, Zenith, Savoy, and Solby Mines of the OUver Iron Mining Co., at Ely, Minn., between 50 and 60 Ingersoll- Rand drills, No. 3 (3") are used. In these mines no records of performance whatever were kept. Tunnel Driving at Low Cost.^ The driving of the Chipeta adit at Ouray, Colo., was not especially notable, as an important operation; but on account of the rapid driving and the resultant low costs, attention was attracted to it and considerable inquiry has been made as to the methods employed. The adit was projected as a working entry to simplify the mining of the American-Nettie quartzite stratum, which had faulted downward. The old entries were tortuous inclines ter- minating at the fault. The portal is in the face of the steep mountain forming one wall of the canyon north of the town of Ouray, at an altitude of nearly 9000', and 1700' above the bed of the river. For economic reasons the power plant was placed at the river and a line of 3-^-" standard pipe laid on the surface to carry compressed air to the adit. This pipe line, 3400' long, has given no trouble in summer or winter. During the installation of the plant and pipe line, work was carried on by hand labor, the adit reaching a length of 263', including the portal section of 115', which was heavily timbered 7X7' in the clear. Machine-drilling was then started and a run, which lasted for five full months, was made, only two rounds of holes being lost in that period. This run of five months (152 days) resulted in driving the heading jlX^jV in the clear, a distance of 1712-^ in hard rock; a monthly average of 342 ^ The best weekly record was 85'; the best month (31 days) was 359'. But two 8-hour shifts per day were employed, economical considerations, not speed, being predominant always. Compressed air at about 100 lbs. was supplied to a pair of 3 J" new Ingersoll drills, both mounted on one single-screw column set horizontally above the muck pile. The round, consisting of from 15 to 19 holes, was drilled — except the lifters — from this setting, the bar being reset for ^ We are indebted to Mr. Walter H. Bunce for this article, abstracted from the Mining and Scientific Press. DRILLING ON LAND 153 the lifters after the muck was away. The cut was taken from the bottom, uniformly. Three drill-men tended the two machines, drilling a full round each shift. An unusual system of mucking was employed, which, perhaps more than any other one thing, may account for the substantial rate of progress that was reached and maintained. The tunnel track, i8" gauge, was carried close to one side of the adit, and a floor, consisting of steel plates and planks, was maintained with the greatest care for not less than 60" back from the heading. This floor was moved forward every round. No switches or turnouts were used; cars measur- ing 20 cu.ft. capacity were specially designed, and these, although weighing, empty, 1000 lbs. apiece, were so perfectly balanced that the empty cars composing an incoming train were easily jumped off the track onto this floor, the loaded cars passed by, and then the empties replaced on the track in detail as required by the muckers for loading. Muck was handled with No. 6 square- pointed shovels. Four shovelers and a mule-driver composed each shift. Track was laid and leveled by the muckers. Each shift, composed of drill-men and muckers, started work together. No ventilating system was installed, the smoke being blown back with air from the compressor. The adit throughout its entire length was perfectly dry. This adit was an independent operation, the employees having no other occupation, so that their total wages are a charge against the work. Their wages were: Foreman, $5; drill men and blacksmith, $4; blacksmith's helper, $3.50; muckers, $3; com- pressor engineers, $3.50 per 8-hour -shift. No bonuses were paid except on Christmas Day, when double time was given. The following costs are computed from March ist, when 1835' (includ- ing the portal section) had been completed, and embrace every item outside of construction and equipment accounts, which were closed before the current accounts were opened. The " power " account covers labor, coal, oil, and lights, everything at the compressor station; " labor " covers all other labor except that charged into ''lumber and timbers"; '^tunnel expense " covers tool-renewals and repairs, blacksmiths' sun- dries, forage, oils and general sundries at tunnel, " Track and 154 ROCK DRILLING pipe " covers cost and transportation of rail, fittings, ties, pipe, and pipe fittings; " expense " covers city ofiice, rent, furniture and incidental expenses. The compensation of the acting super- intendent is nowhere included in the costs as shown. Distribution of Costs Total. Cost per Foot. Tunnel expense Track and pipe Power Lumber and timber. Labor Lights , Explosives Expense Total, 1835' . $556.94 1,532.26 2,862. 71 533-51 11,981. 85 233-70 3, S 22. 06 ^ 836.11 $22,059. 14 31,0.303 1.560 o. 291 6.529 o. 127 1. 919 °-455 tpI2.02 Pipe line through tunnel is 3^' standard black pipe. Track is i6-lb. section, on ties laid 20" apart. Powder (40% dyna- mite) cost $0.1315 at the portal. Close estimation places its consumption at 14.5 lbs. per foot for machine driving. Steam coal cost $3 per ton at the boilers. The air pressure was nom- inally 100 lbs. and a recording gauge kept on the line proved of value in many ways. There was always plenty of air. No charge for depreciation of tools and equipment has yet been entered; renewals and repairs are made and charged currently to " tunnel expense," and the actual value of the outfit to the company is about equivalent to new, as nothing has been allowed to run down. Large vs. Small Drilling Machines.^ The purpose of this paper is to discuss the relative merits of the large 3^ machine and the small 2-y tappet machine in driving develop- ment headings; although the data were obtained from cross- cut headings alone, experience has shown that the results are equally true in drifting, raising and v/inzing. '- A paper by Frederick T. Williams, Mining Engineer, Victor, Colo., enliiled "The Relative Merits of Large and Small Drilling Machines in Development Work," published (subject to revision) in Bulletin No. 8, March, 1906, of the American Institute of Mining Engineers. DRILLING ON LAND 155 Recently we drove two parallel cross-cuts through the same formation, using a 3J" machine at the breast of one cross-cut, and a 2J" machine of the same make at the breast of the other. The results of this work afforded an ideal comparison, since in both cases the headings v^^ere advanced through rock practically of the same hardness and breaking properties; the amount of sludging was equal, and there was no difference in the condition of the steel or the machines, in the air pressure or in the experience of the operating crews. Some operators in the Cripple Creek district contend that there is ground which cannot be handled with the small machine, the holes being too small to contain enough powder to pull the ground, etc. The results obtained in working the property of the Portland Gold Mining Co., however, show that the ground worked by them does not fall in this class. During a period of two years there have been driven, with the small machine, 4 miles and 308 ft. of development headings, through a diversity of ground, including Pike's Peak granite (a coarsely porphyritic type of granite), highly indurated, andesitic or phonolytic breccia, true massive andesite, trachytic phonolyte, tufas, and along dikes of decomposed basalt and hard phonolyte. In every instance a satisfactory record was made. The headings here described were driven through highly indurated, andesitic breccia, having a hardness of from 5.2 to 7.2 and a specific gravity of from 2.2 to 2.8. The action of the breccia under the drill was not materially different from that of ordinary red granite. The breccia was not as free drilling as granite, and sludge accumulated very rapidly after a shallow depth of hole had been gained, but it broke better than granite. Aside from the usual work of setting up, drilling, and load- ing, the machine-men or helpers mucked back, cleaning the floor of muck 3 or 4' back from the breast in order to posi- tion the column properly. If the '' lifters " acted properly at the previous firing, the muck was fairly well thrown back from the breast; but if either missed fire or were^ exploded before the other holes, considerable muck was left at the breast which required much additional labor. The usual time needed to 156 ROCK DRILLING < 12; H Pi O o u o c o o p < p^ o p^ pa fa O o Ah W Pi fH ;?; Ph c 1-1 > H •Sd-BQ pUB g CO - ^ in H lO C 1- 3Sn^ 'JSpMOd Sui -pnpuT s9ATSo]dxg O w c> 01 CO lO c^ «© p] M m^ ^^ 0\ PI Q M CO Os C CI ■;so3 SUTUILU'BJX ]BJ9UaQ C^ rj- H lO ^c c •- OO 1- H CO (- ►- CI €©= ^ ^ ©& C c c O p. OC o xo \C c N O •sguiqo-Bpj Sm^BjadQ JO ;so3 CO OC 0\ u T 4 r- 4© H 4©^ ^ feft •pa^JOAV sijTi^g C <: ■^ h O c VC ^ 1- O auiqoBi^ jo -ONJ t- t- )- Tf 1- 1- 1- ^ H co 1/ -J \f, C^ C7> c ^ \o noojj ly-j CO l> -^ -^ Tf -^ VC LO J3d JOqBq JO ^SOQ n CO r* ~) c^ r. o c CI €^ «> 4© €/5^ CO oC c ^ -t OC CO c ■:i -* h- cc H a: CN c CJv c LO CN oo lO o c h ^ 1- 1- CO ^ J"; OC 1-0 u -0 GO ■□9ai3[D'EJX pu'E sdi(j c ^-^ r^ OC t>. r- CO CO CO ^0 co c- 6^ ^ ee- ^ ^ CO CO c ■^ C^ lO CO OC M 1- CO Cv CO c T xn •sjaiuiuBJx o M OC ^ i-^ M c 6s p CO P- OC >~ CO c< "i tr^ <^ 4© m m^ U-) to ' t-* t^ •SJ3TIIJ\[ pUBH 1 O C •sjadpy; ^u^q;^■EJ^^ CO to -1 CO r CO &^ M 60. 'i- VO 1- \C o •U9]A[ 9uiq;o-Bi\[ -^ <: ^ 1/ -, O -1- ■<: •u <^ ©? ,_^ _^ ^-^ ; I^M yr, M ^-d "q _w rO t^ rt N t^ "rt (U X O •4-' O X O c LT) □ lO !S lO c P c 4 c C c c u ^ p cd u >- 3 p a nj 4-1 C J- »H t/j rt ■4-J 1-1 1h ^ s P > -, > > f^ E > > > 1 rt IX cd y^ rt rt n tjO be c/1 ^ '^ ■? s s t: "V S £ i^ 1 OC t- - ^ s 1/ ■3 00 4^ > ^ u <; c/; CJ < DRILLING ON LAND 157 •S (-1 < IT) H ■^ \o o c ^ -t- ■;jiqg jad -^33^ oc O lO r^ Ti- to C o -t Cs ci CI M oi w c i ci -Ln lo to to O ti r, lO ■uaAUQ ^aaj jo -o^ oc vo to o 4 d <- '^ ^ CN '^ fO M M Cl ^ r. n On ■* l-O CO O to o c ^ w j^ a; I— '^ CO C ^ w •uoj, aad %soj f ct w M Cl W i- o ^ ^ ^ ^ C O O O O O C o CN tT ■^ o w 00 VC o •suox 1b;ox Os w o w ro oo' C r. M O ^ M to VO c c 00 H '"' CO M 1- O) c M ,^ On to VO O CS -^ <:>■ t^ ■^ « u Tl- ■;oojI J9d ;so3 0\ CO CO CO \d O vc NJD m e/> €©^ %<& c LO w o ro CO (N fO c o 00 o 00 CO NC CO ■1S03 jB;oi c H t^ H 4 o a ro m: a^ M r^ to to H o o fO ro On 1— 1 M C NO e^ S5^ m ^ ■a:^9 'SuiAoAjng <0 lO to 01 to t OS « oo c 'SuTA-Bssy 'sassog IN N in o -d- Tt- u ■^ -4 a s u a d X a ;bj9U9Q (N ro N CO w c NO ^ m- 66= ^ c> -t OO ^ C) r^ oc t^ -saiiddng jo ^jso^ !>. W CO CO to oo oc c* c M o r-1 d c c M €i9^ ^ ^ ©^ o r^ to ^ \o On oc ro vc to « to ^ 00 C -t •SUIISTOJJ JO *s°3 c IN lO O 4- -+ -u ■) 'i- r. ro - rt (D X to X3 X 1 JH LO iz: C d m 13 4 c C c ^ o D 3 3 a> u ;=( *" ni rt ^^ (i M IH bO rf -4-» u )H y. s ^ ^ >^ >^ ^ a >> > % > to rt rt rt QJ 1 c3 cti cti bO s ^ TJ T3 > < 6 E3 'V t: '? t s ir ■> 00 i>- 2 to oc t~ > ^ u V2 u < i:)S ROCK DRILLING muck back was 1.25 hrs., but this varied considerably. Flat steel 48X96x1'' sheets were used, from which to shovel the material. These were placed in position 3 or 4' back from the breast by the trammer, just before going off shift. The ground broke fine enough to require little or no sledging. A cubic foot of breccia in place will average 154 lbs. in weight as compared with go lbs. on the muck pile, giving an average of 42% of void space. All the waste was trammed to the shaft 800' distant, and hoisted to the surface. No timber was used in either heading. Table II EXPLOSIVES— DETAILED REPORT OF THE PORTLAND GOLD MINING COMPANY FOR TWENTY DAYS ENDING OCTOBER 16, 1903. Pounds of Powder. Pounds of Powder per Foot Driven. Feet of Fuse. Feet of Fuse per Foot Driven. No. of Caps. No. of Caps per Foot Driven. Large machine (si"). Cross-cut (5.5X7.5') 5 -day mil 491 669 544 17-23 14-39 15-32 S72 I179 S04 30-59 25-35 22.65 116 158 4.07 3 39 3-77 8-day run 7-day nin Averages and totals . - Small machine (2^') Cross-cut (3.5X7') ^HJay run 1704 264 378 262 15.40 11.00 9-45 7.82 2855 672 1129 742 25.80 28.00 28,22 22.15 408 96 151 120 3-69 4. 00 8-dav run 3-77 3-58 y-dav run Averages and totals. . . . 904 9.27 2543 26.08 367 3.76 CHAPTER IX SUBAQUEOUS DRILLING Standard Rates on Subaqueous Drill Work. For the same reasons that governed us in the case of dry work, we have in this chapter reduced the costs to the following standard basis : TABLE OF STANDARD RATES OF WAGES FOR SUBAQUEOUS WORK Rate per Day. Runner Runner's helper Blacksmith ". Blacksmith's helper Fireman , Powclerman Labor , Coal Oil Dynamite Observations at West Neebish Channel, St. Mary's River, July, 1909. As part of the work on the improvement of the inland lakes the channel of St. Mary's River is being deepened by the U. S. Government. Part of this improvement, known as the West Neebish Channel, has been completed and opened to traffic for some time, and during the summer of 1909 work on that part known as the middle Neebish Channel was progressing rapidly. On the completion of the present work there will be a channel from the U. S. Government Ship Canal at Sault Ste. Marie to Lake Huron, 300' in width, and with a depth of 24' at mean low-water level. The portion of the work covered by the con- tract of the Great Lakes Dredge Dock Co. is typical of the work 159 160 ROCK DRILLING east of Neebish Island and contains the following items of interest. The drill plant was installed on a boat of 30' beam and 120' length, center to center of spud anchors. All machinery, with the exception of the drill machines, spuds, spud engines, and the wind- lasses, was housed in a shed 20' wide. The blacksmith shop occu- pied one end of this building next to the coal bunker, which opened on the boiler room. Back of the boiler room was the pump room, containing two force pumps, one for working the hydraulic lifts and one for supplying the water jets. In the pump room were also a small engine and generator for supplying light for the night shift. Next to the pump room was a large room used for a work room and storage. In this there were kept the oil supply, waste, repair parts for the drills, and such small tools as were needed from time to time. There were also a couple of work-benches, one of which was used by the man who prepared the exploders and wires for blasting. An open *' hall " extended the full length of the house on the side next to the drills, all the various rooms being partitioned off except the blacksmith shop and the work- shop. The only obstruction in this passage was a hydraulic cylinder and piston 12" in diameter and 15' 6" long, coupled to an endless chain, for use in moving =— '-' ■ — ■ ^l^u m 7 06 ^B Hi. I I 1 1 1 1 Fig. 76. — The "Auto-screw" Frame for Submarine Drilling. SUBAQUEOaS DRILLING 161 Fig. 78. — St. Mary's River, Mich. Great Lakes Dredge & Dock Co. 162 ROCK DRILLING the drills along their rails. Drill steel was stored on the floor of this passage and steels were handled here by means of block and tackle at the forge. The frame of the boat consisted of seven longitudinal trusses, two of them with wood top and bottom chords and steel web mem- bers, the others being all wood. The wood trusses were 6' on centers and the extreme ones 3' from the outside steel trusses. Between the trusses the deck was carried on 6X12'' sills supported at intervals of 5' 10" by 6X6'' posts, which rested on other 6X12" sills on the bottom of the hull. Between the longitudinal wood trusses bracing was run at intervals of about 20'. The planking of the hull was fastened directly to one leg of the 6X6'' angles, which made up the vertical members of the steel trusses. The boat seemed to be very tight and was almost absolutely dry. The space under deck was used for storing steel, pipe, hose, tools, blacksmith and other rough supplies. The drill outfit consisted of five 6^" Ingersoll-Rand drills, type K 6. These drills were mounted on a frame built of steel angles, an idea of their detail being given by the accompanying photographs. Each drill was raised by a hydraulic lift cylinder at the top of the frame, having a lift of 18' and controlled by a triple valve operated by a hand lever, also shown by the views. The steels used were 35' long over all; 32' of this length was 2?/' round material and had on its end 3' of octagonal sec- tion. This end was of harder steel and was used as the drilling end; 4' of the upper end of the steel was reduced slightly so as to fit the chuck. When first used the steel had an X point, 4f" to gauge, but with use it may wear down to 3" before being sharpened. Thus the holes varied in diameter, from about 6" at the top with a new bit to perhaps 3J" with a worn bit. A steel did about 225' with one sharpening. The depth of water at this part of the channel was from 23 to 24' with a current of 4 to 6 miles an hour. The channel being worked was 150' wide, the other 150' of the subsequent 300- foot channel having been completed. The current near the deep channel was much swifter than that at a distance from the old excavation and this, SUBAQUEOUS DRILLING 163 with the fact of the rock having been partly broken by the work on the other portion of the channel, made drilling near the deep channel quite difficult. The following is a list of the principal efficiency factors observed on this work: Diameter of piston, 6V'. Length of stroke, 12". Kind of rock, Potsdam sandstone. Diameter of bit at starting, 4f gauge, but reduces to about 3" in the work. Length of feed, 18' (6'' hydraulic jacks). Steam pressure at boiler, 105 lbs. Diameter of feed pipe, lY' {2" discharge). Length of steel over all 35', this includes 32' of 2V' round steel and an octagonal end 3' long which is harder than the shaft and on which the point is made. About 4' of the upper part of the shaft is slightly reduced to be held in the chuck. Weight of steel, 2V' diam., 585 lbs. Kind of chuck, U. Number of drills, 5. Type of drill and marks, Ingersoll-Rand, K6. (No. 7501.) Depth of hole, 7'. The average hole is 7' deep, but near east side of channel one row of holes varying from 3 to 4' was drilled. Diameter of holes, 6" at top when finished, .\\" to 3" at bottom. Longitudinal spacing of holes, & . Lateral spacing of holes, 6'. Nature and condition of material: This channel was worked over six years ago and is somewhat damaged and often seamy. Length of shift, 11 hrs. (2 shifts per day). Kind of boiler, Scotch marine, 3 fires, 14' long by 13' diameter. Horse-power of boiler, 200. Steel handled by hand when placing in drill or taking 164 ROCK DRILLING to blacksmith shop; while being sharpened, steel is suspended by chain at end away from forge. Size of jet, J" diameter at point. 7520 cu.ins. water used per jet per cutting minute, 17.4 cu.ins. water per cubic inch of rock cut. Connection of jet, kind and size, 30' of 3'' pipe for main supply. From this for each machine there are 8' of lY' pipe to hose, 30' of f" hose, 30' of I" pipe, and 8' of V' pipe for jet. Drill is moved on track by chain operated by hydraulic power. Supplies brought from Soo by scow and tug. Fig. 79. — Spud Gear on Drill Boat at West Neebish Channel. Coal consumption 25 tons per week, 12 shifts, 840 lbs. per drill per day (i shift). Oil used, f pint per drill per range of four holes; average 9 pts. per drill per shift. Equipment towed by tug; when moved from range to range, moved by anchors and current. Blacksmith's duties, all ordinary repairs and all bit sharpening and welding. Blasting charge, 2 sticks, at 2^> lbs. Blacksmith's duties, size of powder, 60% Forcite gelatin. Size of sticks, 2 X 16". SUBAQUEOUS DRILLING 1G.3 Kind of fuse, Reliable double strength, 8' wire. Also DuPont and Victor double strength. One fuse to hole; i to blast. Men blasting: 3 powdermen, 2 wiremen. Drill strokes per minute varied from 144 to 300. Average running about 240. Bit tempering: hard. Interest and depreciation at 2% per working month on plant, valued at $35,000, $13.45 per shift. Moving boat from range to range consumed 13.35% ^^ ^^tal time costing 13.35% wages per shift = $7.9o. This large amount is due to the speed of drilling, which causes frequent movings of boat. Superintendence, i foreman at $5.00 per shift, 9-25% of hourly- labor. Cost of moving boat, S7.90 per shift, or $1.58 per drill per shift. The following is a rough inventory of the plant in use on this work: One scow, 30X126'. One Scotch marine (3-fire) boiler, 14' long by 13' diam- eter. One blacksmith's forge, blower and anvil with smoke- stack. One blacksmith's bench, 1 vise, i pipe clamp (small). Seventeen spare drill bits; full length 35'. One hydraulic cylinder i2"Xi5' 6", with 3^" piston and traction chain. One Worthington feed pump (small). Two Snow Steam Pump Co. force pumps. One dynamo and switchboard driven by one cylinder belted engine; dynamo, no volts and 42 amperes, D.C. Westinghouse, 5 H.P., 1600 R.P.M. One small vertical washout boiler. Five drill machines, IngersoU-Rand 6V' on track of 2' 6'^ I-beams. Two capstans, steam driven. 166 ROCK DRILLING Four spud engines, each equipped with Superior Iron Works 6X6v/' engine. Four mooring posts (iron). Two double post sheaves. General Notes. Spuds were operated by four two-cylinder Superior Iron Works 6X6V' engines, fed by iV' pipe. Drill steel. "Black Diamond " and "Colonial." Pump for jets was 12" diameter by 5X12", .giving 80 strokes Fig. 80. — Drill Boat at West Neebish Channel. per minute. Pump for hydraulic lift was 16" diameter by 6X12" stroke. The hydraulic cylinder used for moving drills was also supplied by this pump. The moving of the drill frame is done by means of a chain running through a + shaped hole in the steel base of the drill frame. A slotted block is dropped over the chain and it engages between the links, thus dragging the frame along when the chain is moved by its hydraulic cylinder. In each "range" each machine drills 4 holes, therefore there are SUBAQUEOUS DRILLING 167 20 holes to the range. A range generally takes 45 min. to finish. When a range is finished the boat is swung on the spuds by the current. When a cross range is finished the boat is worked diagonally across the channel to the next range below, next to the center line of the channel. The following is a synopsis of the costs per cubic yard of pay rock and per lineal foot of hole while drilling 7' holes a.s observed. It will be noted that the number of feet drilled per shift was remarkably high, due to the excellent organization of the work, and to the fact that there were few interruptions from accidental causes, and to the further fact that excellent hydraulic jets were in operation, and that the men were well trained. TABLE OF COSTS ON STANDARD BASIS Amount per Shift. Totals. Per Foot Drilled. Cents. Per Pav Yard." Cents. 5 drillers at 27^ cts. per hr. (11 hr. shift).. 5 helpers at 22 cts. per hr vSl5-I2 12.10 3 loaders at 30 cts. per hr 3 loaders' helpers at 22 cts. per hr. 1 blacksmith at ^^ cts. per hr 2 blacksmiths' helpers at 22 cts. per hr. . I mpper at i.oo I fireman at 25 cts. per hr I foreman at 9.25% per hr. of hourly labor. Total labor Dynamite, 5 lbs. per hole, 1200 lbs. 60*^ ^) at 12 cts. per pound 300 exploders at 3 cts Coal, 2.1 tons at $3.15 Oil, waste, ^ pint per hole, ^ bbl. at 40 cts. Total for 1680 lin.ft., or 1280 cu.yds. Plant, $35,000, interest and depreciation working month, 2% 9.90 7.26 3-^3 4-84 I.oo 2-75 S.oo 1.62 17.16 «-47 I.oo 2-75 S.oo .06 .16 61.60 144.00 9.00 6.62 2.60 3-^7 8.57 0.54 0-39 223.82 1.3-45 13-32 0.80 2.13 1-34 .66 .oS 4.81 11.25 0.70 17-48 Consumption of dynamite was on the basis of 0.56 lb. nitro- glycerin per yard of pay rock. 168 ROCK DRILLING Fig. 8i.— Drill Frame on Drill Boat at West Neebish Channe Fig. 82. — Foot of Drill Frame on Drill Boat at West Neebish Channel. SUBAQUEOUS DRILLING 169 The above figures are based on an average performance of 240 holeSj Y deep per shift, or 1680 lin.ft. drilled. Since the holes were drilled 3' below grade and were spaced 6X6', this corresponds to 240 X4Xi'5- = 1280 cu.yds. of pay rock loosened. The average drill performance was 30.5'' per drill hour. This does not include contractor's overhead charges or profit, and no account is taken of the preparatory, charges, i.e., cost of getting ready to work in the spring and cleaning up in the fall, or storing equipment during the winter. Profit on the con- tractor's capital, legal expenses, insurance bond, and charity have been omitted. The average cutting speed for the four drills was 2.52' per cutting minute. Ratio of cutting time to total time =0.248. Ratio of idle time to useful working time (cycle time) = o.SS- The following is a general summary of average performance data with deductions therefrom: Shifts I Hours II Number of holes 240 Depth of holes f Lineal feet drilled 1 680 Cubic yards pay rock 1 280 Dynamite, 60% 1200 lbs. or 720 lbs. nitroglycerin Coal, tons 2.1 Labor per shift $61 .60 Lineal feet per shift 1 680 Lineal feet per drill hour 30.5 Lineal feet per man hour 6.g^ Labor per foot drilled in cents 3.67 Cubic yards pay rock per shift 1280 Cubic yards pay rock per drill hour 23.3 Cubic yards pay rock per foot drilled 0.762 Labor per cubic yard of pay rock 4.81 Coal per drill per shift in pounds 840 170 ROCK DRILLING Coal per foot drilled pounds in 2.5 Dynamite per foot drilled in pounds, 60%, 0.715 or 0.429 lb. nitroglycerin Dynamite per cubic yard of pay rock, 0.938 or 0.563 lb. nitroglycerin Dynamite per cubic yard of rock blasted, 0.536 or 0.322 lb. nitroglycerin Cost per lineal foot drilled and loaded exclusive of dynamite exploders, interest and depreciation (cts). 4.21 Total cost per cubic yard pay rock, exclusive of interest and depreciation (cts) 1 7.48 Total cost per cubic yard pay rock, including interest and depreciation, estimated (cts.) 1S.53 Total cost per cubic yard blasted (cts.) 10.6 Ratio of cubic yards blasted to cubic yards of pay rock. 1.75 Time Study. — In drilling a range of 20 holes, with a 5-drill boat, each machine drills 4 holes, and when the longitudinal axis of the boat is parallel, or nearly so, with a swift stream, the debris that is washed out of the upstream holes by the jets or blown loose by blasts, drifts down upon the drills,which are working farther, down stream and clogs them, making an increase in the time necessary for drilling, cleaning and often loading the hole. For this reason the upstream drills are nearly always ahead of the others in their work, and the lowermost drill usually has to finish the range while the others stand idle. A time study is given below for the operation of this boat. No time was taken on drill No. 3. No. I was the downstream drill and No. 5 the upstream one. SUBAQUEOUS DRILLING 171 Number of observations . Lineal feet Average depth of holes . . Drill number Process. Drilling hole Finishing hole Waiting for loaders Loading Waiting for shot Getting into new position. Time of cycle Number of observations . Lineal feet Average depth cf holes . . Drill number Process. Drilling hole Finishing hole Waiting for loaders Loading Waiting for shot Getting into new position Time of cycle 39 holes. 273 43 holes. 301 7 feet No. I. No. :.. Mil 2:00 0:25 0:05 0:25 0:15 0130 3:40 Av. 3:27 1:09 0:43 1:19 1:04 1:10 8:52 Max. Min. 7:00 4:45 3:00 3-15 2:40 2:40 23:20 1:25 0:15 0:00 0:15: o;io 0:20 2:25 Av. 2:30 1:08 0:32 1:02 1:00 1:04 7:16 Max. 5:00 4:40 1:50 3:10 2:30 1-45 18:55 16 holes. 113 16 holes 7 feet. No. Min. Av. M. No. 5. Mil m. AV. Max. 1:50 0:20 0:10 0-45 0:10 ^■35 3:50 2:44 0:38 0:38 1:10 1:05 i:ii 7:26 5-50 1:45 1:15 2:50 2:20 1:50 15-50 1:05 0:00 0:10 0:35 0:30 0:25 2:45 2;io 0:29 0:38 1:10 1:08 1:03 6:29 4:05 1:05 1:25 2:45 2:35 1:10 13:05 The limiting drill, therefore was No. i, which averaged 8 min. 52 sec. per f hole, while No. 5 averaged 6 min. 29 sec. Edwards Brothers' Drill Boat (Observed, 1909).— This boat is working at deepening the channel of the St. Mary's River just east of Neebish Island, and a little above the Great Lakes. It is small, but sound and in good working trim. Her antiquated appearance would seem to belie this fact, but when her history is known there is really nothing contradictory in the two state- ments. It was built about ten years ago and was then equipped with the best up-to-date machinery. Upon comple- 172 ROCK DRILLING tion, this boat Avas not put into commission^ due to the fact that the company owning her got into some sort of litiga- tion which prevented it. In 1909, Edwards Bros, purchased the boat and put her into commission in the summer. Their contract calls for 860 holes and the time limit is five weeks. As said, the boat works very efficiently as far as the drilling machinery is concerned, but much time is consumed in shifting it. Fig. ^3. — Edwards Bros.' Drill Boat, St. Mary's River. This is due to the fact that both the spud anchors and the wind- lasses must be operated by hand. The boat is of wood through- out, her hull being built on the regular scow lines. She is 80' long and 24' wide, and is equipped with two IngersoU-Rand drills, type 13 D.H. 2. Spacing of the holes being 6', each drill must do seven holes to a range (end holes being 4' apart). The method of moving the drill frames along the deck is not by means of an hydraulic jack and an endless chain as is usual. Here there is a chain passing under each drill frame and winding onto a small steam windlass at each end of the boat. SUBAQUEOUS DRILLING 173 Attached to each drill is a small chain and hook which, when it is desired to move the drill frame along the deck, is engaged in a Hnk of the larger chain, and the proper windlass set in motion. The track on which the drill frame slides is made of flat steel strips. The face of an angle on the outer edge of the boat forms one of these and the other is a flat piece of steel attached to the deck some 3' from the angle. The drills are lifted by means of hydraulic jacks, which are fed by a 12X4JX10 Worthington pump. Another Worthington Fig. 84. — Spud Gear on Edwards Bros.' Drill Boat. pump, 6X4X6, working at 50 strokes per minute, furnishes water for the washout pipes at 250 lbs. pressure. The washout pipe which uses this high pressure washout water is composed of three sections of pipe of three sizes, f , -i^-, and f . The last section is so flexible and weak that the driller's helper has a very busy time keeping it straightened out and in operation. The drill bits used are of Black Diamond steel. These bits are 37' in length and 2'' in section. The lower ends, ' however, are upset for the pointing to 2.^' The points are; 174 ROCK DRILLING of this shape +, being, when newly sharpened^ 4^^ but wearing away to 3 V' before resharpening. Drill steel is handled by hand, requiring about 11 min. to replace a dull bit with a sharp one. One of these bits weighs 387 lbs. and will generally drill 35 holes. Spare bits, as well as a pump, boiler, coal bin, and blacksmith shop and outfit, are all housed in a wooden shed covering the larger portion of the deck. A rough inventory of the equipment of this boat is as fol- lows : One drill boat, 80X24'. One powder boat. One cutter. Two drills. Two steam winches for moving drill frames along deck. Two hand winches for operating anchors. Four hand operated spuds or anchor posts for mooring the boat. One boiler working at 95 lbs. gauge. One hydraulic lift pump, Worthington, 12X4JX10. One force pump for washout 6X4X6, 50 strokes per minute. One forge. One anvil. One bench and vise. Extra drill bits. The following principal efficiency factors were observed : Diameter of piston, 5^". Length of stroke, 10". Klind of rock, Potsdam sandstone. Diameter of bit, 4-^', reduces to about 3^' before sharpening. Shape of bit, +. Lift, 16'. Steam pressure at boiler, 95 lbs. Length of feed pipe and diameter of feed pipe, 2" connections from main to standard, where iV' pipe slides inside of 2" pipe. The maximum length on the standard was 32' and up to that point the lead is about 25'. SUBAQUEOUS DRILLING 175 Length of steel, 37'. Weight of steel, 387 lbs., 2" diameter. Chuck is the same as the U in principle, only instead of a single U bolt to tighten drill there are two separate bolts and nuts. Two drills. Type of drill 13 D.H. 2. Depth of hole, 6' average, varies somewhat with bottom. Diameter of hole at top, 5". Longitudinal spacing of holes, 6'. Lateral spacing of holes, 6'. Nature and condition of material: the bottom was worked over about six years ago and is somewhat broken up and is seamy from the previous blasting. Cleaning of holes done by jets. Length of shift, 11 hours, 2 shifts. Size of job, five weeks, 860 holes. An upright boiler. Forty H.P. boiler. Steel handled by hand entirely. Jet, I", 24.2 cu. inches of water needed per cu. inch of rock cut by bit; 3760 cu. inches of water needed per jet per cutting minute. Connection of jet, i" pipe, to which is connected f" hose. The jet pipe is f", with a i" section about 8' long on the end. The y pipe is reduced to f '^ at end. Drill moved on standard by chain moved by steam wind- lasses. Supplies handled by scow from Soo. Four tons of coal per day = 2000 lbs. per drill per shift. Oil used, I bbl. in ij weeks = 1 2 ^ pints per drill per shift. Equipment floated. Blacksmith does repairs of drill boat, bits and dredge re- pairs. Blasting charge, ij sticks, 3 lbs. Pluto powder used, 60%. Size of sticks, 2X16". 176 ROCK DRILLING Kind of fuse Victor, d. s. 12. One fuse used per blast. For time of blasting, see Time Study. Two men blasting. Day foreman, at 16.2% day's wages. Interest and depreciation on plant, valued at $10,800 at 2% per working month =$4. 15 per shift. Working force : 2 drillers, 2 drillers' helpers, I powderman, I powderman's helper, 1 blacksmith 2 helpers, I fireman, I nipper, I foreman. The observed performance of this boat was 8 holes of 6' each in 255! drill min. In a shift of 11 hrs. this is equivalent to 41 holes, or 246 lin.ft. The captain of this boat counts on 84 holes in 22 hrs., which checks well with the observed performance. The spac- ing of these holes being 6' each way the cubic yards of material 41X6X6X6 , 1 . loosened would be = ^28. Holes beme; drilled about 27 ^ ^ 2! below grade the pay yardage would be 226. Based on this performance the following synopsis of costs per lineal foot drilled and per cubic yard of pay rock has been deduced. No account will be taken of contractor's overhead charges or profit, prepara- tory charges, legal, insurance, bond and charity, medical expenses, etc. SUBAQUEOUS DRILLING COSTS 177 Amount. Totals. Per Foot Drilled. Cents. Per Pay Yard. Cents. 2 drillers at 27^ cts. per hr. (11 hr. shift) . 2 helpers at 2 2 cts. per hr I loader at 30 cts per hr I loader's helper at 22 cts. per hr. 1 blacksmith at ^^ cts. per hr 2 blacksmiths' helpers at 22 cts. per hr . . I fireman at 25 cts. per hr I nipper at $1.00 I foreman at $4.65 per day, 16.2% Dynamite, 3 lbs. per hole, 123 lbs. 60% at 1 2 cts 50 exploders at 3 cts Coal, 2 tons at $3.15 Oil, 0.6 pints per hole = 24^ pts. at 40 cts per gal 05 84 30 42 63 84 75 00 6.S Total for 246 lin.ft. or 226 pay yards Plant, $1(5, 800, interest and depreciation, 2% per working month $10.89 5-72 8-47 2-7.^ 1 .00 4-65 14.76 1.50 6.30 4.42 2.32 3-44 1 . 12 0.41 1. 89 6 .00 U.60 2.56 0.50 4.82 2.53 3-75 1 .22 0.44 2 .06 ^■S3 0.66 2. 78 0.54 S57.26 4.15 23.26 1 .69 ^S-33 1.84 The following is a general summary of average performance data with deductions therefrom : Shifts I Hours II Number of holes 41 Depth of Holes 6 ft. Lin. ft. drilled 246 Cu. yds. pay rock 226 Dynamite, 60% 123 lbs. Coal, tons 2 Labor per shift $;^^ . 48 Lin. ft. per shift 246 Lin. ft. per drill hour 11 . 18 Lin. ft. per man hour 1.86 Labor per lin. ft. in cts 13-60 Cu. yds. pay rock per shift 226 178 ROCK DRILLING Cu. yds. of pay rock per drill hour 10.27 Cu. yds. of pay rock per foot drilled .92 Labor per cu. yd. pay rock cts 14.82 Coal per drill per shift in pounds 2000 Coal per lin. ft drilled, lbs 16.25 Dynamite, 60%, per ft. drilled, dynamite ^^ lb. nitroglycerin 3/10 lb. Dynamite, 60%, per cu. yd. pay rock, dynamite .545 lb. nitroglycerin .327 lb. Dynamite, 60%, per cu. yd. blasted, dynamite .375 lb. nitroglycerin .225 lb. ^ . cu. yd. blasted -Ratio T — = i.AK. cu. yd. pay ^ Total cost per lin. ft. drilled and loaded, exclusive of dynamite exploders, interest and depreciation 16.66 cts. Total cost per cu. yd. pay rock, exclusive of interest and depre- ciation 25.33 " Total cost per cu. yd. pay rock, including interest and depre- ciation 27. 17 '' Total cost per cu. yd. blasted, including interest and deprecia- tion iS-73 " Drill No. I, number of holes drilled while under observation, 5. Average depth, 6'; lin.ft., 30. Drill No. 2, number of holes drilled while under observation, 3. Average depth, &, lin.ft., 18. TIME STUDY Drill working Finishing hole Wailing for loading gang I/)ading Waiting for shot Getting into position . , Time cycle No. of Obs. No. Min. 4:25 0:20 0:25 0:50 1:30 1:05 8:35 Mean 6:35 0:52 1:52 2:01 2:37 2:06 16:03 j\lax. 8:50 2:30 4:05 3:40 3:50 2:20 25:15 No. No. nf Obs. Min. 0:30 0:15 1:45 1:05 1:50 8:55 8:02 3-^3 1:17 3:00 5:42 2:00 23:14 12:35 6:45 1:5s 4:15 9:50 2:10 37:30 SUBAQUEOUS DRILLING 179 Drill No. I was the upstream and No. 2 was the downstream. The cutting speed of No. i was 0.915' per cutting minute or 54.9' per cutting hour, while the same time for No. 2 was 0.726 and 43.56. This shows that No. i worked the faster, and it was due no doubt to the fact that the debris from No. i washed downstream and impeded the drilling of No. 2. The average cutting speed for the two drills was 0.82' per cutting minute or 49.2' per cutting hour. The average ratio of cutting time to total time for both drills was 0.223. ^^^ delays amounted to 49.5% of total time and the ratio of idle time to useful (cycle) time v\^as 0.98. CHAPTER X SUBAQUEOUS DRILLING {Continued) Operations at Bl5rth, England.^ The work at Blyth was for the breaking and removal of rock very similar in structure to the sandstone of the St. Mary's River. One dredge of the elevator type was in use and in a day of 24 hrs., all stops allowed for, the average performance was 158 cu.yds. Besides the dredge there were two outfits for breaking the rock. One was the Lobnitz rock-breaker and the other a drill barge having six drills that were Hfted by steam power and guided by hand. The Lobnitz rock-breaker averaged 182 cu.yds. per day, while the drill boat averaged 81 cu.yds. per day. The cost per cubic yard drilled and blasted by the barge was 35. , while by the Lobnitz rock-breaker it was only i^. 2.5c?. The cost per cubic yard for dredging by the elevator dredge, the rock being drilled and blasted by the barge, was 2s. 6d., same for the Lobnitz breaker 2s. 2d. Allowing 4% interest and 2-1% depreciation on the dredge, valued at ;/^i 9,000, the additional cost per cubic yard for removal of rock broken by the drilling and blasting would be 8.2J.; same for that broken by the Lobnitz breaker was 7.1^. COMPARATIVE COSTS IN ABOVE SYSTEMS (Local Wages) s. d. Drilling and blasting rock by barge per cubic yard 3 o Dredging same, 2s 6d, plus S.2d 3 2.2 Total 6 2.2 Breaking rock by Lobnitz rock-breaker i 2.5 Dredging same, 2s 2d, plus y.id 2 9.1 Total 2 II .6 ^ The information in this article was collected by Mr. Gilbert H. Gilbert. 180 SUBAQUEOUS DRILLING 181 Difference in cost per cubic yard in favor of removal of rock broken by means of the Lobnitz breaker 2S 2.6d. Saving on 500,000 cu.yds. = ;^54,i66. An interesting comparison is furnished between the above two methods of breaking rock and that by use of Ingersoll-Rand submarine drills on the St. Mary's River. Costs in cents per cubic yard of drilling and blasting, using Ingersoll-Rand submarine drills, 18.45 -I- 1.05 (interest and depre- ciation) = 19.50. The drop drills on the barge at Blyth= 72.90. Lobnitz breaker i^ 2. 5^/ = 29.30. Saving in cost of breaking 500,000 cu.yds. by means of the Ingersoll-Rand sumbarine drill as compared with the drop drills on barge at Blyth and the Lobnitz rock-breaker is as follows: Saving in cost by use of Ingersoll-Rand drills compared to drop drills, $264,800. Saving in cost by use of Ingersoll-Rand drills compared with the Lobnitz system, $49,600. Note. — It will be noticed in the first comparison that rock broken by the Lobnitz system could be dredged about 15% more cheaply than rock broken by the drop drills at Elyth, due to the former method furnishing a smaller-sized rock. But with the use of the Ingersoll-Rand drills this 15% disappears, for the resulting rock by this process is of a size that the elevator dredge could handle as easily as that broken by the Lobnitz system. Submarine Rock Excavation (Port Colbome Harbor Works, Welland Canal, Canada). This work was for the removal of 360,000 cu.yds. of hard stratified limestone con- taining some flint. Two three-drill drill boats were used on this contract. The total time the drill boats were in operation was equivalent to 5200 days' work of one drill boat. The average depth drilled by each drill per hour was 4^; this included all delays. The total feet of drilling was 655,600 or 1.8' per cu,yd. Operations were carried on in an exposed position; much delay was caused by high winds, rough water, and the cold, inclement weather. 1S2 ROCK DRILLING The average weight of explosive used was li lbs. of 70% dynamite per cubic yard paid for. The dynamite cartridges were 1-^X36", weighing 5 lbs. each. Owing to the uncertain weather conditions, each hole was blasted as drilled in shallow cutting, when the cutting was deep and the surface of rock close to the bottom of the boat, the boat was moved and the holes fired in batches. When holes were fired in batches the results were unquestionably better, but where the boats may be driven off by sudden storms it is not safe to have a number of holes loaded, as the connecting wires are liable to be broken, the hole lost, or the vessel endangered by the hability of the dynamite being exploded by the drill steel when operations are resumed. The spacing of holes depended entirely upon the nature of the rock. In clearly stratified rock, holes were spaced farther apart. Spacing 6XS' was tried, but was found too great and had to be redrilled. Five feet spacing and 6' back was usually safe, but in the very hard material 5X5' was not always sufficient. The depth that holes were drilled below grade depended upon the nature of the rock. If stratified, one bed below, whatever the thickness of the strata, gave good results. It was usually found necessary to go 3' below the grade line. Improvement of Oswego Harbor, New York, Kingston, Rogers & O'Brien, of Buffalo, Contractors,^ This con- tract was for the removal of graywacke, a hard silicious cemented sandstone, to form a channel 15' deep. The rock formation was in horizontal beds of about 24'' in depth. It was not homo- geneous, but of fragments of varying degrees of hardness, cemented together. At times the drill bits would make 10' of hole without dressing, and again not more than i'. The loss of steel through abrasion and dressing was 4 lbs. per 100' of hole drilled. The contract price to grade was $2.75 per cubic yard, no allowance being made for material removed from below grade. The drill boat employed was a wooden vessel 82X26X6!', * The data on this article were collected by Mr. Gilbert H. Gilbert. SUBAQUEOUS DRILLING 183 carrying two 5'' Ingersoll-Rand drills mounted on the side of the boat and fitted with an hydraulic feed with a stroke of 12'. The operating crew consisted of 6 men for each shift, a black- smith and helper being carried in addition, but working in day- time only. Two shifts per day of 11 hrs. each. The following costs are for 1000 cu.yds. of pay rock: Linear feet, 8660. Cubic yards, pay rock, 1000. (Note local wages.) Cost Items. Cost per Linear Foot. Cents. Per Cubic Yard Pay. Cents. Labor. ■^ ^ days at $^ i $1023.00 148.50 12.70 80.80 II. 81 I-71 -15 •94 102.30 doi tons coal at S"? 14.85 1.27 8.08 42^ gals, of cylinder oil at 30 cts Shop repair, steel and other stores .... Total drilling $1265 .00 680.00 54.00 14.61 7-85 .62 126.50 68.00 5-40 Dynamite, 4000 lbs. 75% at 17 cts Fuses, 1800 at 3 cts Total drilling and blasting Interest and depreciation on plant esti- mated at $15,000 at 2% viTkg. mo.. $1999.00 381.00 23.08 4-40 199.90 38.10 Total $2380.00 27.48 238.00 In the above tabulation of cost no account is taken of con- tractors' overhead charges, organization or preparatory, insurance, charities, legal, medical expense, etc. The following is a summary of the data obtained, based on the performance and costs in drilling and blasting 1000 cu.yds. of pay rock: Number of drills, two 5'' Ingersoll submarine. Material, hard sandstone. Shifts worked 66 Hours worked . 726 No. of holes 1650 Depth of holes 5.25' 1S4 ROCK DRILLING Linear feet drilled 8660 Cubic yards pay rock 1000 Dynamite, 75% 4000 or 3000 lbs. glycerin Coal, tons _ . . 40 1. Labor per shift (average) $15-50 Linear feet per shift i^i Linear feet per drill hour 5.9^ Linear feet per man hour (14 men, 2 shifts) 1.7 Labor per foot drilled, in cents 11. 81 Cubic yards pay rock per shift i5-iS Cubic yards pay rock per drill hour 0.69 Cubic yards pay rock per foot drilled 0.116 Labor per cubic yard pay rock, cents „ . 102.30 Coal per foot drilled, in pounds „ . 11.4 Coal per drill per shift, pounds 750 Dynamite per foot drilled, 75%. . .0.462 lbs. =0.346 lbs. glycerin Dynamite per cubic yard pay rock, 75% ... 4 lbs. = 3 lbs. glycerin Dynamite per cubic yard blasted 2 lbs. = li lbs. glycerin Cost of drilling and loading (all items exclusive of dyna- mite fuses, interest and depreciation) per lin. ft 14.61 cts. Total cost per cubic yard pay, exclusive of interest and depreciation 199.90 '' Dredging cost $500 = 1000 lbs. or 50 cents per cu.yd. of pay rock 50,00 " Total drilling, blasting and dredging per cubic yard, pay rock, exclusive of interest and depreciation (38.1 cts. pay yard) 249.90 " Same, including interest and depreciation 288.00 ' ^ Contract price per cubic yard removed above grade $2.75 cubic yards blasted Ratio of 7-. 1 2.00 cubic yards pay Observations on Livingstone Improvement of the Detroit River. Improvements are now being carried on along the lower part of the Detroit River. This work bears the name of the Livingstone Improvement of the Detroit River. Upon its com- pletion it will be no longer necessary for both up and down bound vessels to use the same narrow 300' channel between SUBAQUEOUS DRILLING 185 Bois Blanc Island and Amherstberg. Instead a new waterway will be at the service of downbound vessels. The whole job is of such magnitude, extending as it does from Limekiln Crossing out into the lake, that the contract for it was let in four distinct sections. A very interesting section of this work is No. 3. The work is entirely subaqueous, and consists in cutting a channel 23' deep, 300' wide, and 18,250' long, in the hard limestone forming Fig. 85. — Blast: Five Tons of Dynamite. Submarine Rock Work, Livingstone Channel, Detroit River, Mich. the bed of the river at this place. O. E. Dunbar and T. B. McNaughton signed the contract for this portion of the work. But they, too, sublet their contract. The three sections so sublet are each 100' wide and 18,250' in length. M. Sullivan has the eastern 100' section. Dunbar and Sullivan the middle loo', and the Buffalo Dredging Company the western 100'. To carry out his part of the contract M. Sullivan has a plant of three large dredges, the Gladiator, Hercules, and Old Glory^ 186 ROCK DRILLING Fig. 86.— Drill Boat " Destroyer.' Fig. 87.— Drill Boat " Destroyer." SUBAQUEOUS DRILLING 187 with their attendant scows and tugs, and also three drill boats, the Destroyer J Dynamiter , and Exploder. It was the Destroyer that was blown up during the summer of 1908, receiving damages at that time so severe as to necessitate her rebuilding. The Destroyer is by far the most modern of the M. Sullivan drill boats. Her hull is built entirely of steel and the deck is of the same material. 100' long, 7^^' wide and 6' deep, she is indeed a staunch boat. Three transverse bulkheads divide the interior into four watertight compartments, each 27^X33'. Two longitudinal bulkheads divide each of these t^2>' compartments into 27^X1 1' sections. Four manholes in these longitudinal bulkheads furnish a means of passing from one side of the ship to the other. A wooden house 80' long and 24' wide incloses all machinery, excepting the 4 drills, 2 capstans, and spud engines. The spuds or anchor posts are operated by double .6X8 engines made by the Chase Machine Company of Cleveland, Ohio. The capstans, one at each end, are operated by small engines made by the Bath Iron Works of Bath, Me. The drills are the IngersoU-Rand K 61, having 6^'' cylinder. Inside the wooden house near the center of the boat is a large Scotch marine boiler, and near it on the upstream end the coal bunkers are situated. Alongside the coal bunkers on the upstream end of the boat is the blacksmith's forge. At the other end are the two Worthington pumps. There is a passage- way on the side of the house nearest the drills, clear excepting for the spare drills and the hydraulic cylinder used to move the; drill frames along the deck. The house also contains thel d)mamo for the electric lighting and the small engine for running- it. ! Drill Data. Type of drill, Ingersoll-Rand, K 61. Diameter of piston, 6V'. Stroke, 9". Feed 19', about. U-chuck. Steam pressure, 100 lbs. gauge at boiler. Speed about 225 strokes per minute. 188 ROCK DRILLING Fig. 88. — Changing Steels on Drill Boat " Destroyer." Fig. 89. — Changing Steels on Drill Boat " Destroyer.'' SUBAQUEOUS DRILLING 189 The machine is moved up and down by hydraulic power. Worthington pumps, 14X6X10, 5" suction, 4" discharge, pres- sure about 300 lbs., are used for this hydraulic lift. The drill frames are moved along the deck by a chain that passes through the holes in the front ends of the frame of each machine to the ends of the boat where, by means of two sheaves about 5'' apart at each end of the deck, the chain makes two 90° turns, and then passes into the house, parallel to side of boat, and terminates in the piston rods of a double-acting hydraulic cylinder. To move a frame along, a pronged piece of steel is slipped over the link of the chain nearest the frame, so that when the hydraulic moves this pronged piece of metal bears against the frame and moves it along the deck its required distance. The tracks on which the frame slides are steel plates 4" wide and |" thick. The device for securing the frames in place after they have moved is as follows: A chain passes through holes in the rear of each frame, which chain is anchored at each end of the deck. The frame is secured to this anchored chain by means of two clamps, one at each end of the frame. Drill point, best octagon tool steel, 4.V' and 4'' Length of steel, 36' 9". Circular section above tool steel point, 2]-" and 2^' Bits handled by hand. They are taken out of machine and taken to blacksmith as follow^s: First the U-chuck bolts are loosened until the drill bit comes out. The drill cylinder is lowered by the hydraulic as low as possible and a chain slipped around the piston rod with its other end wrapped around the bit near the center of its length. The hydraulic is then used to raise the drill and attached bar, until bit overbalances. As it thus gradually overturns it is caught by five or six men and carried by hand and slipped through a near-by window into the house, where it is handled by black- smith and helpers. Steel is tempered till file will not touch. Holes cleaned by V' jet; 60.7 cu.ins. of water needed per cubic inch of rock cut by bit; 2970 cu.ins. water needed per jet per cutting minute. 190 ROCK DRILLING Water supplied by Worthington pumpj lo X4 X 10, No. 193854, 4" suction, 3" discharge. Pump speed, 47 strokes per minute. Water pressure, 150 lbs. A 2" pipe runs full length of boat, and has a connection near its center to the pump. Opposite each machine a small piece of pipe runs to the outside of the boat through the wall of the house. A i-^' flexible hose, wire- wound, runs some 20' to a 6" piece of pipe that is connected by a right angle to a f pipe about 12' long, at the end of which is a reducer, plus about 10' of y pipe. A block and tackle suspends the washout appa- ratus at the top of the frame so that the apparatus is easily handled by one workman. Depth of hole, 12.5' average. Diameter of hole, 4V' steel makes about a 5!'' hole, 4" about 4-^". Longitudinal spacing, 5'. Lateral spacing, 5'. Limestone badly broken in spots. Rock has about iV of sand on top. Holes shot, 396. Two drills make 5 holes to a range, and two make 4 holes =18 holes. As a rule 22 ranges are drilled, therefore 22X18 = 396. Pluto powder for blasting, 60%. Sticks of powder weigh 18 oz. each, size 8X2'''. Charge, 17 sticks per hole. Blaster and foreman did loading and blasting. Four drills on boat. Scotch marine boiler. Pressure at boiler, 100 lbs. gauge. Length of feed pipe, 60' from steam chest of drill to main. Diameter of feed pipe, 4" main, slide 2" and ij". Contract reads 750 good working days. Length of shift, 11 hrs. Two shifts. The tug bringing the men to work leaves the dock morning and evening at six o'clock. Eastern standard time. SUBAQUEOUS DRILLING 191 Three boats must be visited; at each leaving a crew and taking off a crew. 4 drillers at $3.02^ =$12.10 per shift 4 helpers at 2.42 = 9.68 I blaster at 3-30 = 3-30 I foreman at 4.65 12.8% = 4-65 I blacksmith at 3.62 = 3-62 2 blacksmiths ' helpers at 2.40 = 4.80 I fireman men, at total 2.75 = 2.7s I shift, 14 = $40.90 2 shifts, 28 men, total = 81.80 Contract price was: For rock $2.80 per cubic yard, earth 50 cents per cubic yard. The work of the blacksmith is mainly repointing drill bits and welding broken ones. The points of the bits are of the best hexagonal tool steel. This must be welded to the shank of the bit. Then the pointing must be done. To assist in handling, the steel, wooden horses are used having a roller on top. Eight tons of coal are used in 24 hrs. = 2000 lbs. per drill per shift. Use 55 gals, of drill cylinder oil in 3 days i bbl, of cylinder oil in 4 weeks = 20^ pints per drill per day (i shift). Coal is brought alongside in a bunker with a chute mounted on a scow and is transferred from the chute to the drill-boat as follows: On the end of the chute there is a framework for an elevator in which a box or skip is raised and lowered by means of a cable, leading back to a dinkey engine on the stern of the scow. Start- ing with the skip empty on the deck of the scow, a door in the chute is pulled open by means of a lever, and enough coal IS run out to fill the box. Signal is then given and the loaded skip is hoisted some 15'. An inclined trough leading into the bimker has in the meantime been prepared. As soon as the bottom of the skip is on a level with the top of the inclined trough, that end facing the trough falls and the coal 192 ROCK DRILLING runs out into the bunker of the drill-boat. The skip is then lowered and the trap-end automatically closes. All the Sullivan boats have the same method of getting coal that the Destroyer has. Reference will therefore be made to the Destroyer in the reports on the other two boats of M. Sullivan Co., the Dyimmiler and the Exploder. The cost of handling is not included in the cost of coal, for Fig. 90. — Drill and Drill Frame: Drill Boat " Destroyer." the reason that the company owns its tugs. The cost of the coal loaded on scows at the dock is $3.15 per ton, and the cost of handling would be 35 cts. if done by piecework or on a contract basis. No figures were obtained as to repairs, as no record was kept. When breaks were not too serious, the crew on board made repairs. When they were very bad and the crew could not make them, the spare drill was set up and the old one boxed and sent back to the factory. Each boat of the Sullivan fleet has two foremen: SUBAQUEOUS DRILLING 193 a day foreman at 12.8% of the day wages; a night foreman at 11.7% of the night wages. Besides there is one man known as the walking boss who has charge of the three boats. After their day's work is finished the men are taken ashore, where they hve at their own expense. The walking boss is given quarters on board one of the SuIHvan dredges, the Old Glory. Lighting is furnished by a small dynamo operated by a 4 H.P. engine. Interest and depreciation, figured at 2% per working month, on plant valued at $40,000, = $15.50 per shift. Moving the boat from range to range consumes 3% of the total time, costing 3% of the shift's wages or $1.23 per shift (day) = $0.31 per drill per day (i shift). A rough inventory of the equipment of this boat is as fol- lows: Four drills and equipment. Extra bits. Four spuds, 4 spud engines, 6X8. Two steam capstans. One boat, 33' Xi 10'. One Worthington pump for hydraulic, 14X6X10. One Worthington pump for washout, T0X4X10. One Scotch marine boiler, 100 lbs. (gauge-pressure). One hydraulic cylinder for moving frames. One dynamo and 4 H.P. engine. One blower, i forge, i anvil, i bench, i \'ise, i cutter. One powder boat. Four dry cells. Three switches. Explanation of Time Study. The five headings on the left are the logical divisions into which a complete drill cycle sepa- rates. The minimum, mean and maximum periods of time consumed in each of these operations in the left-hand column is given under its proper heading. The entries under "Mean," "Max," "Useful Working Time," need the following explana- tion. Supposing four "Drill-cutting" periods for four holes 194 ROCK DRILLING >e O O '-' 00 M M O O O O to O H ro O fO o « o w ^ NO lO "* '^ O • ■ bD -^ ■ C3 '■3 uj O ■ c w 4:: .S *^ ■*-' ""^ 'r" "I? ^ aj ^-^ .5 >~: O bDbOiS o o ro q O O M o ro o ^ c CI O ■+ IN -^ ro c O O O lo o r? p. 9 7t r! c^ u-,00 'O 00 -4-t e5 -r) O O Qj q q ."75 H r-^ o O CI p m Lo 10 -^ t-~ O O O O bO rt bO O -=•4) __ -M ZJ J2 OP ^eI^ u; =3 O o SUBAQUEOUS DRILLING 195 3 ^ f3 > s Oh ^I u c 3 o ■4-1 r- ^£2 6 I- t-. 0)^ - t^ ni bO bO -■'3 O ■ ■ rt 1^ ; ^ o 2 ^^'^ c-S o O ID ' -" 3 _j nJ I, td o oj --^ C bo bC— 3 o.;2 c X & C^ u-l M rrj C J IN LO O O O LT) O - Q lO lO I r'l O ■* ■* ^ O O O -^t O \j~) -rir m *-* W/ 0\ W CO "+ « Cn CO i-t CH Lo PI ro tJ- t^ i^o O O o^o-^^ • !=! Ji bO"^ ■^ . 1 C/J 4-1 "XJ JJ o 2 ^ o .ti > ^ 196 ROCK DRILLING wei-e 5, 3, 4, and 10 min. respectively. The 5, 3, 4 being close together are summed 5+3+4=12, and the average time 12^3 = 4 obtained; 10, being for some reason too high, is left out of the average. Still this 10 represents one operation, and so to take due account of it, it is given simply the weight of the average, 4. The total "Useful Working Time" is then 5+3+4+4=16. The difference between 10 and 4 or 6 represents the "Excess over Useful Working Time." This system has been used in Fig. 91. — Drill Boat " Destroyer.'' this Time Study. The "Useful Working Time" is given both in minutes and seconds and in percentage of the total time. This is true also of the "Excess Time." The latter is classed under Idle Time, in the same columns with which appear the time lost in the operations of Waiting for Last Hole, Moving Boat^ and Miscellaneous Delays, together with the percentages of these to the total time. In this connection may be mentioned the fact that after a frame has drilled its required number of holes it must be idle until the slowest drill on the boat finishes the last hole in its range. SUBAQUEOUS DRILLING 197 During an observed period of 3219II drill minutes, 31 holes at 12^ = 387-1-' were drilled. Per 4-drill minute or for the boat this would be 387V in 804' 58". On the basis of an ii-hour day = 660 minutes, 25 holes would be put down during a shift ^312^'. The spacing of the holes being 5' each way and drilled about 2V below grade the cubic yards of rock loosened would be = 232 cu.yds. Based on the above performance and the before-mentioned sup- ply and labor costs, and taking no account of the contractor's over- head charges or profit, preparatory charges, legal expenses, insurance, bond and charity expenses, the following costs per lineal foot drilled and per pay yard have been deduced: COSTS Amt. Shift. Per Foot Drilk-d. Cents. Totals. Per Pay Yard. Cents. 4 drillers at 3.02^(11 hrs.)=$i2.To 4 driller's helpers at $2.42 " = 9.68 21.78 6.96 9.40 I blaster at3.3o " = 3.30 2-54 3-43 I foreman (12.8%) at4.65 " = 4.65 7.95 I blacksmith at3.62 " = 3.62 2 blacksmith's helpers at 2.42 " = 4.84 2.71 3-6s 8.46 I fireman at 2.75 " = 2.75 2-75 0.88 1. 19 Total 40.94 1309 17.67 Coal. 4 tons, 12 hrs. at3.i5 =12.60 12.60 4.00 5-44 Oil 3.30 pts. per hole =10.30 gal., I r hrs. at 40 cts. per gal 4.12 1-31 1.78 60% dynamite, 480 lbs., 11 hrs at 12 cts = 57.60 18.30 23.61 24.80 7432 32.02 Total for 312.5' or 232 pay yards 115.26 36.70 49-69 Plant S40.000, interest and depreciation z'lr per working month 1 5- 50 4-91 6.68 The average cuttmg speed for the four drills was 0.233 lui.ft. per cutting minute or 13.98' per drill hour, including getting into position, etc. The speed per minute for drill No. i was 0.206', while that for No. 4 was 0.232' per minute. No. 2 was the upstream drill and it would naturally be expected to do the best work, inasmuch as 198 ROCK DRILLING the current would tend to wash down the debris from the upper holes to the lower ones, thus impeding them. But here the upstream drill made the poorest showing of any. It not only- made poor time itself, but it held up the other three drills over 3 hrs. waiting for it to finish its last hole. The explanation for this is that No. i was working on a face left shattered and covered with debris from a recent blast. The holes would refill almost as quickly as drilled. The average ratio of cutting time to total time for the four drills was 0.51 17, and the ratio of idle time to useful working time (cycle time) for the four drills was, 0.979. "Destroyer." The following performance data and deduc- tions therefrom are based upon an average shift performance: Shifts I Hours II Number of holes 25 Depth of holes, feet i2§ Lineal feet drilled per shift. 312^ Cubic yards pay rock per shift 232 Dynamite, 60% 479 lbs. = 287.4 lbs. nitroglycerin Coal, tons 4 Labor per shift $40.94 Lineal feet per drill hour 7.1 Lineal feet per man hour 2.025 Labor per foot drilled 13-09 cts. Cubic yards of pay rock per drill hour 5.27 Cubic yards of pay rock per man hour . , i-5oS Labor per cubic yard of pay rock 17-67 cts. Coal per drill per shift 2000 lbs. Coal per foot drilled, in pounds 25.6 60% dynamite per foot drilled, gross 1-53 lbs.; nitroglycerin 0.92 lb. 60% dynamite per cubic yard pay rock 2.06 lbs.; nitroglycerin 1.24 lbs. 60% dynamite per cubic yard blasted 1-65 lbs.; nitroglycerin 0.99 lb. SUBAQUEOUS DRILLING 199 „ . cubic yards blasted Ratio, — r^ — —^ T 1.25 cubic yards pay rock Total cost drilling and loading per lineal foot, exclusive of dynamite and interest and depreciation 18.40 cts. Total cost per cubic yard of pay rock, exclusive of interest and depreciation 49-69 cts. Total cost per cubic yard pay rock, including interest and depreciation 56.3 7 cts. "Exploder." The second of M. Sullivan's drill boats on the Livingstone Improvement of the Detroit River, the Exploder, represents a very old type of craft. The hull of this boat is composed entirely of timber. Her construction differs but slightly from the ordinary type of wooden-decked scows. The Exploder is 79' long and 27' 4'' beam. The house is 12' high at the front end and somewhat less at the back, 43' long and 18' wide. This boat is also provided with spuds operated by small double engines with 6 X 10 cylinders. These spud engines on the drill side of the boat rest on the deck, while on the other side they are on the posts that form the guide for the spuds. This boat spent the whole winter up at Alpena, working amid great cakes of ice. She has three drill frames. Drill Data. The drills are LigersoU- Sergeant type. H-1S-9. Piston diameter, 5^'^ Stroke, 8". Feed, 18' about. U-chuck. Steam pressure 100 lbs. gauge at boiler. Number of strokes, about 300 per minute. The principle on which the drill frame is moved along the deck is the common hydraulic. The hydraulic cylinder in this case is 9' in length. The tracks on which the frames slide are 1X3" plate laid on a 4X6" sill at the edge of the deck and a 45-lb. standard rail for the rear track. For holding the frame in any given position a chain passes near the rear of the frame. Each machine has one of these chains that is fastened at the 200 ROCK DRILLING ends to the deck. When the drill is in its desired position it is held there by snapping a clamp into a convenient link of the chain and thereby fastened securely to the rear part of the frame. Steel bits have 4^" and 4" points. Point is made of black diamond steel. Length of steel, 37' 6" Circular section of steel 2 and 2I" in diameter. Fig. 92. — Drill Boat " Exploder. Steel handled by hand with the assistance of a hook hanging from ceiling. Steel tempered hard till file will not touch. Holes cleaned by V' water jet. Worthington pump 12X5^X10" supplies water for jets. Speed of pump, 21 revs, per minute. Water pressure, 300 lbs. The washout water comes from the same pump as does the water for the hydraulic lift. It is therefore necessary to be careful and not turn the washout water on full force. Holes are loV deep. SUBAQUEOUS DRILLING 201 Holes have diameter of 4^ and 5!" at top, but decrease in size a little towards the bottom. Longitudinal spacing, 5'. Lateral spacing of holes, 5'. Material drilled, limestone. Rock is hard in spots. Sand on top of rock is iV to 2' in depth. Holes shot at one time 24X15 = 360, i.e., 24 ranges of 15 holes ■each. Pluto powder used, 60%. Size of sticks 8 X 2", weight 18 oz. Thirty-two sticks used for charging one hole. All holes are shot at once. Leads run up from the last two or three holes loaded and when these are touched to the contact points all loaded holes go off. Blasting gang consists of blaster and foreman. Three drills used on boat. Boiler is Scotch marine, 12 X8'. Steam pressure at boiler, 100 lbs. Length of feed pipe, 60' from main to drill. Contract reads 750 good working days. Length of shift, 11 hrs. Two shifts. , Working force per shift is as follows: 3 runners at $3-02} = $9.07^ per shift 3 helpers at 2.42 = 7.26 '^ I blacksmith at 3.62 = 3.62 2 blacksmith's helpers at 2.42 = 4.84 I blaster at 3'3<=> = 3-30 I fireman at 2.75 = 2.75 I foreman at $121.00 per mo. = 4.65 ^^ Day foreman $121 per mo., 15.1% day wages.. $35.49^ Night foreman $110 per mo., 13.7% night wages 35.09^ Total, both shifts 70.59 Contract price $2.80 per yard for rock and 50 cts, for earth. Smith's work is keeping the drill steel in shape. 202 ROCK DRILLING Eight tons coal used in 24 hrs. = 2666 lbs. per drill per shift. Fifty-five gals, of drill cylinder oil used in one week, lubricating oil, 5 gals, a week=T3J pts. per drill per shift. Coal is handled by the company's equipment and no cost added for this work. The manner of handling is described in report on the Destroyer. Coal costs $3.15 per ton. The cost would be 35 cts. per ton more if company did not operate their own tugs. ■ 1 ^^^^^^I^^^I^IBI BaW^^p^^^M^^^_^^^^^^^^^^B!;' - ' '•'■'-^^^WBI^f 1. 1 Wf -^="=^-^^9^91^' ' ' bB Fig. 93.— Drill Boat '* Exploder." Repairs were not kept track of, the crew makmg them when necessary. Two extra machines kept on hand. Each boat of the Sullivan fleet has two foremen. There is also one man known as the walking boss who has charge of the three boats. Quarters for crew were ashore, and were paid for by them- selves. Interest and depreciation on plant, valued at $25,000, at 2% per working month, = $9.60 per shift. SUBAQUEOUS DRILLING 203 Moving boat from range to range, 3.6% time, costing 3.6% of day's wages or $1.28 per shift, =$0.43 per drill per shift. A rough inventory of the equipment of this boat fol- lows: One wooden boat, 79^X27' 4". Three drills and equipments. Eleven bits. Four spuds. Four spud engines, 6 X lo'^ One steam windlass. Two hand windlasses. One boiler, 8X10'. One force pump, Worthington, 12X5JX10/' One blower. One engine for blower, 6XS'\ One forge. One anvil. One bench. One pipe clamp. One hydraulic to move frame, 9' long. One Penberthy injector. One small dynamo for lighting, with engine. One powder boat. One cutter. The only record of performance obtainable on this boat was for one shift for a period of one week. It is as follows : Date. No. of Holes. Depth. Powder. Hours. August 27, 1909 August 28, 190Q August 30, 1909 August 31, 1909 September i, 1909 September 2, 1909 49 47 44 35 46 31 539' 517' 484' 385' 506' 341' 1760 lbs. 60% 1690 ' ' 1580 - 1260 1660 '* II20 " Total 252 42 2772' 462' 9070 1512 66 Average per shift II 204 ROCK DRILLING Fig. 94. — Handling Steels on Drill Boat " Exploder." On a daily basis the cost would be as follows ; COSTS Force. Rate Standard. Cost. Cost per * . in Cents Foot Cost per Pay Yard in Cents 3 drillers 3 helpers 1 blacksmith 2 blacksmith's helpers. I blaster I fireman I foreman ^3.02^ 2.42 3.62 2.42 2-75 4-65 $9-07 7.26 3.62 4-84 3-30 2-75 4-65 1.96 1-57 0.79 1-05 0.72 0.60 1. 01 2.92 2.34 1. 17 1.56 I -06 0.89 1-50 Total . 60% dynamite, 15 13 lbs. at 12 cts. Coal, 4 tons at 3.15 Oil, 5 gallons at 40 cts 35-49 181.56 12.60 7.70 39.20 2-73 0.44 11.44 58.20 4.05 0.65 Total Plant $25,000, interest and deprecia- tion at 2% per working month 231-65 9.60 50.07 2.08 74.34 3-08 SUBAQUEOUS DRILLING 205 Pay yardage is based on the following: ii' holes, less 3' drilled below grade, equals 8' pay drilling. Spacing of holes, 5' X5'. 5^X 5^X8^X42 , , =311 pay yards per day. 27 In the above tabulation of costs, no account has been taken of contractor's overhead charges or profit, cost of getting plant into commission in the spring, and cleaning up in the fall, storing equipment during winter, legal expenses, insurance or charity, etc. The following is a general summary of average performance data with deductions therefrom: Shifts 6 Hours 66 Number of holes 252 Depth of holes 11' Lineal feet drilled 2772 Cubic yards pay rock 1866 D)Tiamite, 60% 9070 lbs.; nitroglycerin, 5442 lbs. Coal, tons 24 Labor, per shift $35-49 Lineal feet per shift 462 Lineal feet per drill hour 14 Lineal feet per man hour 3.5 Labor per foot drilled, ,in cents 7.70 Cubic yards of pay rock per shift 311 Cubic yards of pay rock per drill hour 9.45 Cubic yards of pay rock per foot drilled 0-675 Labor per cubic yard pay rock, in cents 11.44 Coal per drill per shift, in pounds 2666 Coal per foot drilled, in pounds 17.3 60% dynamite, per foot drilled Gross 3.27 lbs., nitroglycerin 1.962 60% dynamite per cubic yard pay rock Gross 4.86 lbs., nitroglycerin 2.91 60% dynamite per cubic yard blasted Gross 3.53 lbs., nitroglycerin 2. 118 206 ROCK DRILLING H P O O t— t P< P o o Is :2i W o o S to c d 0) o O o in o lO CO ro o ro M ^ u-j s c M IT) o c t4- s I ?s^ S c CN M C CO is 2°S ^ o ii o t; w) •^ -^ « o p rf aj S 7^ tJ3 Er^-i^ Hf H .r-t CI CI M ■<^ N Cl H HH hU 1 bo O >J-) o o lo O rr rT tT r? ro W ■O M 'O VO cl -f- c^ ^ W -I- ro £ ) OC lO CI r> H^OH C ■^ t- M (1> i C C u c > CJ'^ ^ ^ o CO H W CO c/: . 1^ o O LO a ^ rt ro f? p •^o cJ' i^ CN b b M '6^ d 2; yi O rO J>. -o o 'O to LO LO o o LO ^ rt ^ 7? H CI ^ CI ON H LO O LO W o ^ O cj LO LO ■LO lO LO LO rt lO r? Ol LO p LO OJ H LO H Ul o O LO o lO .s rt o p p M s H PI 1-1 b Tj- ro ro d w S N 1>- -+ Tt- '^ b G nJ a bD o bi) •I— 1 C tn X! O nJ ft O fal D o ^ ^ fl G O , >-; CTl > f^ ■U fi ■n T! C HJ q u o ■> _a OJ c o G S o OJ c o o 3 ^ -.-' p c fl O) OJ s CO O r[ QJ 'O G O ^ H j-< ho QJ G in ^ s >< ID bo n XJ rt -1-1 M-* td tt" O ^ ■ O — 1 bO li^ m tu +5 ^ ft ■ jU "be ^ u rt cS JG fU i^ O ri O !D .2 1—1 4> -^ u 218 ROCK DRILLING Pi Q lo 1 _o p ^ p CS rr in ■D vb '^ M 'r^ O 1 tij 1— ( r^ 00 OS ^ '"' O t-> o ly 1 lO O o LO M M 7^ !>■ -* ■^ C^ IH vb ^ ^ CS r^ 6 12; lO c O ly o lO ^ lO yp M <-o 0) H CS c '^ M (^ ■^ c c . ^ o c lo in en ^ u 1- ;d- M ft 9 1 (V) O ro O^ 1 bi 1— 1 H C^ CC 'O hJ l-< O ffi !zi c lo in 1/ ■) TJ^ H o rl" tt ^ ""^ IH c< > O -+ OC U-) CS b ^ 1- CS d d ij-) lo lo \J O ^ o (S rO ^ h M rO ^ l_ - ro -^J- C C O C ly -■ 8 dj :t tN o c CS Cfi 13 j>. c i\ sr^ CC r- ^ ^ w c ^ lo J M O a^ ^: u -) c c m w -d u -3 C Ln -: p. ■rt > o r* ■^ c ^ lo H c b bJ ^ ■ H CS ON '"' d i u -) ■" T lO ^/ ■) u -) u-> Z u f^ ■:> IN ly -) C lo >- xt ■^ H (N u ~i -b r* ■) -+ t c K C b. trt b. >1 r T3 c c 3 J c b •£ i 1/ 1; i c^ i 1 i ^ ^ b 5 c 5 f^ i 1 3 5 c ^ ^ r/1 J=! rl CO is ♦J J^ nr) )_, d (Tl (-1h rt J ^ ni rd C 1 OJ 1 o is ^ £f en "1 cd Ih he u cu rl u, 0) 'fi n J3 (U rl3 h _^ O ■P (D T3 X) ?J -5 '^ ^ ^ bo 3. R « 4J 65 a .^ ^ c O C]> s t i ^ rt « bp d n 3 ^ B g nj U , ^ - -^ ?^ ?- hn +-" Tl _c 1) a ;3 UJ T) ^ P. 2 ''3 cd bO «] tn ^ i rt O y^ bp ^ H bn u d in 4f ■H o ^ bJO ^ ■c t; 3 -n -d ^ ^ S i^ u Tl hn rt c H T1 0) (1) W ( 1 (1) <1> IH T^ ^ O w § ^ o .a "J 3 ^ -t: CHAPTER XI SUBAQUEOUS DRILLING {Coniimied) That portion of the Detroit River Channel Improvement known as the Livingstone Channel was divided into four con- tracts. The contract for section No. 3 was taken by O. E. Dunbar and T. B. McNaughton, and was sublet in three equal sections to Dimbar & Sullivan, Buffalo Dredging Company, and M. Sullivan. These sections for the sub-contract each include 100' of the 300' channel and extend the full length of the section. Dunbar & Sullivan have the sub-contract for the excavation of the middle 100'. They have on the work two drill boats, the ''Earthquake" and the ''Hurricane." " Earthquake." The '' Earthquake " is a steel boat with a wooden house, length 106', breath 30', and depth 5' 9". The house is 89X19X13' in height, sloping down to 12' at the back. The steel hull has a wooden deck of 2'' planking. The interior of the hull is divided into four compartments by three transverse bulkheads. One of these compartments is 2W long and the other three 25' long. These four water-tight compartments are each divided by three longitudinal bulkheads into four sections 7 J' wide. The method of framing the steel work together is by standard angles and bracket plates. The floor angles are 32 ^3 ^i" and they extend across the boat continuously. At the sides of the boat they are joined by bracket plates to 3^X3X1" angles, which latter are a support for two longitudinal 6X8'' stringers running the length of the boat, one on each side. Where the floor angles pass through the longitudinal bulkheads, 3-^X3" angles extend up the buklhead vertically and connect at the bottom with the floor angles and at the top with the stringer angles running lengthwise of the boat. 49" from each side of the boat is a wooden stringer 6X4" to help support the deck, 220 SUBAQUEOUS DRILLING 221 Fig. 97. — Drill Boat " Earthquake." Fig. 98. — The " Earthquake " in the Foreground. 222 ROCK DRILLING which is supported by vertical angles 4X3^^, spaced 8' apart, these being secured to the floor angles at their lower end. In connection with the hull there is a steel tank about 7X21X3^ into which the exhaust water from the hydraulic lifts runs. This is used in winter, and the water so returned is heated by the exhaust from the pony feed pump and pumped back into the hfts again, thus keeping the machines thawed out. In the summer the tank connects with the river so that cool water is used in the lift. Boiler. The boiler in this boat is a "Doghouse'' Redwood. It has three possible ways of feed, (i) injector, (2) washout water pump, (3) regular boiler feed pump. At the back of the boiler is a feed-water heater, a tank about 4' deep and 3' in diameter, into which passes the exhaust steam from the washout pump and the hydraulic lift pump. The following is a list of the factors observed in the operation of the boat and drills : Ingersoll-Rand, H 61 drill. Diameter of piston, 5J''. Stroke, 6^'. Drill feed, 19', more or less. U-chuck. Steam pressure, no lbs. at boiler. Speed of drill, 300 strokes per minute. The drills are raised by the usual hydraulic lift. The method of moving along the deck is by means of a chain and a double- acting hydraulic cylinder. This hydraulic cylinder is 11' long and 12" in diameter. There is a 6"X8" sill having a 4X|" plate on top that runs along the edge of the boat on which the front part of the frame slides. The rear part of the frame bears on a block of wood 6X8", which slides on a similar bar of steel fastened to the wooden deck. The frame is locked after mov- ing by means of a hook on the rear part of the frame that snaps into eyebolts screwed into the deck. These eyebolts are spaced 5' between centers. Diameter of starting bit is 3 -J". Plus point, +. Length of steel, 34' 7". SUBAQUEOUS DRILLING 223 Section of steel, circular, size, i|-". Handled by hand. Tempered till file will not touch. One-half inch jet cleans holes. Worthington pump supplies jets. Speed of pump, 17 R.P.M. Water pressure, 200 lbs. Connections, size and description: From 3" main within the house various connections lead to a \" hose about 30' long. This is attached by means of a nipple and elbow to a f'' pipe 15' long which connects with the same length of -J" pipe. This last section forms the end of the jet. The hoisting arrangement is attached at the elbow of the upper end of the f '' pipe. Depth of holes, about 14'. Diameter, 3!" at top. Longitudinal spacing of holes, 5'. Lateral spacing, 5'. Material drilled, limestone. First row of holes which overlaps old blast is bad digging. Number of holes shot per blast, 249, or 12 rows of 20 to 21 each. Powder, 60%, made by the contractor and called Pluto in the market. A 50% saving is said to result from this home manu- facture. Sticks are isJXif" and weigh i^ lbs. Twenty sticks loaded in each hole. Foreman, blaster, runner and helper do the loading. Four drills make up drill outfit. Doghouse Redwood Boiler, 7IX12J'. Feed pipe about 75' from drill feed to main. Connection from a 3" main within the house runs under the drill frame to a 2" pipe, which runs half way up the frame. A li" pipe slides inside of this 2'' section and connects with the steam chest of the drill. Length of job, 750 good working days. Eleven hour shift. Two shifts. 224 ROCK DRILLING Contract price, $2.80 per yard for rock and 50 cts. per yard for earth. Blacksmith repairs drill bits, makes welds on broken bits and all repairs. Twelve tons of coal used in 24 hours = 3000 lbs. per drill per shift. Fifty-five gallons of oil used in two weeks on drill cylinder = 4.6 pints per drill per shift. Coal is loaded on the deck of a scow at the Amherstburg coal dock and towed out by the company's tug to the boats, where it is shovelled by hand into the coal bunker. Coal costs $3.15 per ton. The cost of handling if the company did not own the tug would be 35 cts. per ton. There is one walking boss to oversee both boats, also one foreman on each boat. Day foreman at 12.8% of day wages; night foreman at 11.7% of night wages. Interest and depreciation on plant valued at $45,000 at 2% per working month = $i7.75 per shift (day and night = $35.5o). Moving boat consumes 3^% of total time, costing 3^% of wages per shift =-81.33 per day shift = So. 33 per drill per shift. A rough inventory of the equipnent of this boat is as follows: One boat, io6'X3o'X5' 9'', built in 1904. One cutter. One powder boat. Four drills and equipment. Four spud anchors. Four spud anchor engines. Two steam capstans. Seventeen bits. One hydraulic cylinder for shifting drills, 11' long X 12^' diameter. One Doghouse boiler, 12^X7-^. One feed-water heater. One injector. One small engine for boiler feed. One small Worthington pump for washout water. SUBAQUEOUS DRILLING 225 One Worthington pump for the hydraulic lift, 10X7 Xio". One anvil, one forge, one bench. One vise and pipe clamp. One blower and blower engine, small. One dynamo for lights, with a small engine. One tank for heating feed water for hydraulic lift, 7X21 X3' The Sand Pipe. To facilitate drilling operations on the two Dunbar boats a device locally known as the sand pipe is used. It has three important functions: (i) It serves as a guide to the bit in starting a new hole; (2) it serves as a guide and protec- tion to the charging tube; (3) it prevents sand from getting into the hole when the sand pipe has once been freed from sand by the washout jet. The sand pipe is in itself really a large cast-iron funnel, being Casting ^^ Sand Pipe Fig. 99. some 18" across the top and having a spigot about 4' in length. The sand pipe rests in position in a casting of the above shape. This casting is fastened at its ends by rivets to the ends of two tees that furnish a means of raising and lowering the sand pipe. Each of these tees passes upward and is free to sHde through brackets attached at intervals to the side of the vertical frame of the drill. A small cable is attached to the upper end of each tee that passes upward over a sheave on top of the frame and downward, terminating in a box of counterweights. This box of weights is provided with small wheels on its under side so that it may move more easily over the inclined bracing of the frame upon which it bears. To the end of this weight box a rope is fastened which leads down to the deck. To raise the sand pipe and its supporting casting and tees, a chain is passed around the chuck of the drill and one of the tees. The ysual hydraulic lift then raises both drill and sand pipe. The lowering is 226 ROCK DRILLING Fig. ioo. — Throttle of Hydraulic: "Earthquake." Fig. ioi. — Spud Engine on " Earthquake." SUBAQUEOUS DRILLING 227 accomplished by means of the rope on the end of the box of counterweights. In operation, the sand pipe is lowered first of all over the place where a new hole is to be drilled, and it is the last thing raised after loading before moving to the next hole. The advantages derived from the use of the sand pipe are as follows: Ordinarily the drill bit is practically unsupported for its full length, and when the rock is very hard, it is difficult to start a hole. The end of the bit bounds around in all direc- tions, destroys its point, bends it and sometimes necessitates the changing of the bit before the hole is actually started. The sand pipe eliminates this because it is allowed to slide down into the water before a hole is started. The end of the " funnel " comes in contact with the overlying sand and by its own weight soon works its way to the solid rock. Thus the drill steel which is now let down has a support and a sleeve to work in a distance below the surface of the water equal to the depth of the water and sand. The clearance between the steel and " funnel " should be about -J", but it is generally a little more. If the sand is deeper than the spigot of the funnel, the end of the sand pipe will of course not rest on the rock. But as far as forming a guide for the steel is concerned, it answers every purpose. There is one complication introduced when the hole to be drilled is very deep, and the top of the rock is near the surface of the water. The sand pipe cannot of coin-se, be let down lower than the surface of the rock; the *'lift" of the hydraulic is limited, and so for holes deeper than 13' (on the Earthquake) the end of the bit would not be clear of the sand pipe when the " hydrauhc " had raised it as high as it could. Hence in order to charge the hole the drill has to be disconnected from its steel and the steel has to be raised out of the " pipe " by means of a chain fastened to it and the piston rod. This has to be done for each hole of greater depth than 13', but where the rock is very hard, it more than pays for the trouble in avoiding the delays arising from changing the steel several times in order to get a hole started, and also in the smith's work saved. Again, after a bit has once started a hole, the complete drilling 22S ROCK DRILLING is generally accomplished without interruption. But if there is no sand pipe, as soon as the steel is raised, the small loose stones and sand tumble down into the hole and the drill has harder work the second time than the first. On one of the Sullivan boats a bit caught in such a hole and it was six hours before it could be disengaged and the hole charged. The sand Fig. I02. — Drill on " Earthquake." pipe, when it rests on the rock, eliminates this. When it does not rest on the rock and there is a layer of sand between the spigot end and the rock, its value is not as great for this purpose, but it still helps, due to the depth of sand it does penetrate. But even when it does not rest on the bottom it does more than assist the steel in getting a clean hole; it SUBAQUEOUS DRILLING 229 helps in charging. It is no trouble at all to start the charger, because the " funnel/' with its i8'' opening, is easy to locate. The spigot does the rest and the time of charging should be much reduced. Where the current is swift the charging is very difficult ordinarily, and so a sand pipe would help materially. Again, with no sand pipe the charger in moving around the edge of the drilled hole often causes a small avalanche of stones and sand to completely fill it, necessitating redrilling. Fig. 103. — Tender of the " Earthquake.' The use of the sand pipe is therefore, with the usual washout jet, recommended anywhere except when the rock is clean and soft or the drill bar has to be removed from its chuck before loading, " Earthquake." The following figures for cost per lineal foot drilled and per cubic yard of pay rock are based on the average performance over a period of four months, or 206 shifts. The average depth of hole was taken as 12'. The holes were drilled about 3' below grade and the cubic yards of pay rock are figured on that basis : 230 ROCK DRILLING Average over 4 months, 82 1' per day. Average over 4 months, 411' per shift. Average over 4 months, 572 cubic yards per day. Average over 4 months, 286 cubic yards per shift. COSTS ON STANDARD BASIS Force. 4 drillers 4 drillers* helpers . 1 blacksmith 2 blacksmiths' helpers . . . I fireman I foreman, day, per. mo. . I foreman, night, per mo. I powderman Day shift Night shift Rates of Wages, Standard. $3 -02^ 2 .42 62 3 2 42 2 121 00 12 -8% no 00 II -7% 3 ■30 $12.10 9.68 3.62 4.84 2-75 4.64 4.24 3-30 Total labor 60% dynamite, 1150 lbs. at 12 cts. Coal, 12.3 tons at 3.15 Oil, etc., 4f gals, at .40 Supply total. Total , Plant, $45,000.00, interest and depreciation at 2% per working month Cost per Day. 521.78 8.46 2-75 4.64 4.24 3-3° 40.93 40.53 $81.46 138.00 38.74 1.87 ;i78.6i ) 260.07 35-50 Cost per Foot in Cents. 5-30 2.06 .68 1.12 1-04 .80 9.96 9.88 9.92 16.80 4.72 -23 21.75 31-67 4-32 Cost per Cu.yd. in Cents. 7.62 2.96 .96 1.62 1.48 1. 16 14.32 14.18 14.25 24.20 6.78 •33 3^-3^ 45-56 6.21 No account has been taken of the contractor's overhead charges, profit, cost of getting plant into commission in the spring, or clearing up in the fall, storing equipment during winter, legal expenses, insurance, charity, etc. Dynamite per lin.ft. drilled 60%, gross, 1.4 lbs.; nitroglycerin, 0.84 lb. Dynamite per cu.yd. pay rock 60%, gross, 2.05 lbs.; nitroglycerin, 1.23 lbs. Dynamite per cu.yd. blasted 60%, gross, 1. 51 lbs.; nitroglycerin, 0.906 lb. ^ . cubic yards blasted Ratio — r^ J r= 1-^27. cubic yards pay rock ^ ' SUBAQUEOUS DRILLING 231 The following is a general summary of the data on file in the government office at Amherstburg, Ont., obtained with the consent of the contractor. The items marked * are deductions from the data on file. Shifts worked Hours worked Hours delay Number of holes * Number of holes per shift Lineal feet drilled Depth of holes Dynamite, pounds 60% Coal, tons * Feet per day * Feet per ■drill per hour, working . . , . * Feet per drill per hour, total * Feet perman hour , Labor per day, dollars * Labor per foot drilled, cents * Coal per foot drilled, pounds * Coal per cubic yard pay rock in lbs * Cubic yards pay rock * Cubic yards pay rock per day * Cubic yards pay rock per shift . . . . , May. June. July. 50 52 52 514 55^ 562 36 16 10 1,786 2,083 i>459 36 40 28 22,353 23,084 18,658 12.52 11.08 12.80 21,911 28,321 35.843 324 328 332 894 888 718 10.89 IO-39 8.30 10.17 10.10 8.15 2.90 2.88 2-33 81.46 81.46 81.46 9.12 9.18 11.36 29.0 28.4 35-6 41.2 42 50 15.740 15,600 13,250 630 600 510 S^S 300 255 August. 52 554 18 1.743 33 20,363 11.68 41,375 327 784 9.19 8.90 2.54 81.46 10.40 32.1 47-6 13.750 529 265 "Hurricane." The second Dunbar & Sullivan drill boat on section No. 3, of the Livingstone Improvement in the Detroit River Channel at Amherstberg, is known as the '^Hurricane" Its history is rather interesting. It has two boilers, and this in itself is a rather unusual thing for so small a boat. About four years ago Mr. Dimbar had two 50' frame boats On the coast, and when it was decided to bring them into the Detroit River it was found necessary to cut each boat into two 25' sections, to get them through the canal. Later the steel sections were bolted together and it was then suggested that instead of having two very small boats it would be advisable to make one large boat. They were accordingly bolted together, making a 100' four frame steel boat. This boat, like the "Earthquake," is provided with sand pipes. (See page 225). The wear on the inside of one of these pipes in a season enlarges it from 3" to 3V'. This boat 232 ROCK DRILLING O 5 p •o o o m ) o O lO y: y. ^5 -f Tf y? '"' r? r? -t CO ;^ W o \o M lO lo M M ^ ir~^ j-1 1^ CO IJ-; o o u-j O lo o i-o O LO y, tj f-O p w ro p M " -t- CO JJ b N H W LO M M ro r^ ;^ CO -t H :/: u-> O O to lO Ln LO LO „ 1= ro ro CO CO M VT' p fO "^< ^ s b r^ b b ^ b M 01 J^ ■ (N 1 -o J>- r^ t^ ir^ i^ t^ ^^- lO lo O m O O lO m T) o 9. 9. M p n 9 01 H w c> '-f ^C vb Cl M U-, u-. h-1 CO ■vC O ir-, o lO O i-Tj L/"; ^ W 5 H p :? P -± fO w CO ;^ M (M ci ^ uo M M ^ Cl > .^ <-o lo w c/^ o O U", 11". O O „ .5 q ro M p -t -+ p CO Tl- fo S H OQ M M ^ b H CO 01 ^ W ^ X ^' .S-^ ^O 1/-, j:-. r— i^ r^ -i^ u o o O O LO O i^j O O y. -)- U-; M ;^ ^■ ro p V? .^' H % M CO vb 01 01 lO CO -O o u-i lo O U-, U-) O t-n xo Tt (M w CO p CO rt :1" yo X j-> cf C M y? Tt r? lO ^ LO CO p d S b CI b H CO b c H LO CO ■ m :2o -f o -O so o so -o ^ o LO o o O "-r, O O If) M 1-1 H lO p CO r!" y? w H O M ^ CXi Ol 1- ^ M hj CO O o K l/^ O o ^. ^J-l u-. O ii-> LT-, H ^ 01 9. ?. M Ol r! r? LT, o 0) b CI 'O M CO LO ■^ M CO •i l-l W ij-i •Wl lO O o LO ^ c o M CO oi ;^ TJ- CO 01 M ■"^ S b i>. b H CO b b 01 ^ d 2; d CO -■ ^' 2;o r^ CO r~- oO 00 CO ■c 00 bo bD O c c r a. a, 'c L, E ^ "3- 0^ .0 Q C O bC C w bO ) bn 'tfl a 1— 1 ■4; 1 re 1— ■> c .5 P. ?? bp ti s •3 ^ s (1) bo r, c >^ ■^ o -ID 14-1 Ci 1-1 o rt (\i C ri XI o X) u C/} i) „ ^ B hO ^-l n Mh U XJ a o ^ 2 ?J -^ ^ o a ■*-■ o SUBAQUEOUS DRILLING 233 w <: a < o pq I— I o m m 1 jj ij- H in ^ H 71- rT' K"' 1 i-J TD )_, C> in m (N ^- b\ 1 O 1 — 1 11 m w M 1 lO o in m m O p 1 u o o lO m O in in; u >■• > rO -^ !>. OO -t i^ r-- m O^ (i) ^ M i-i fT. f I « 1 '''^ o in o U" . ■n O 1 ^ in in j 6 p M f q r- •t '-'■ 10 ^ .m b c^ M C-1 m H H ro 1 t^ ir^ -t 1 :S ro •^ . U-; O in O m, ^ W r? r? r? in M r? 1-1 t3 H o in H ^ in -t o M H rn ^O w W o ir ^ »n in u- ; in m '/jj H (N ro -^ CI p rf :i >■ S O ^ - i-^ 00 ON vb s> b (^ •^ - CO in 00 tA jj r? CT) 01 01 i^j re \A ^ f^ m MD in ^ -t )A 1 — ( M M t^ M O o O in O in C c 1/ in X ^ tn rt :^ r rn C •Tf - 1- (^ -i o w T ■ j:^ >o O c ^ OC r M ^ C M ^ H ro o C7. d o •u -) in O in 1/ -> u -i in 1/ T % 7t r* n ro C c 1 ;^ ■ 7I h in b (N M M in 1- 1- rf •j od x^ (N' tT LO o in m in C ^* s M in ;t H p "t; f ^ P. o ^ )--l Ci JA b M t-^ 00 ^ ^ , o O O c C 1 IH CJ h9 Tt P c- c "; u in oC ^ !>. N 1- ^ - OC r^ ^ u Ci '* H CN CO i-T o t^ at in c o in I' i U -1 c u -; in C u -t 1 Tj- c p w M ^ H r* "D in c^ H 0) b H ro m H 1- r< ' ^ t- - b, 3 b, C ^c rt ' pi£ b 3 « ^ b V Tl rrt X! w c! bO X3 o .S ;3 C -4-* fl s ■u £ c c bO S aj 1 4) S rt bC B .s 2 l-i -4-1 ^ VJ +-' Oh ^ 1 1) 3 XI bO C nJ x; ■a s; X) X! m ■? c/J X) J3 X3 ^ aj c J 2 ^ •13 234 ROCK DRILLING I < O w P^ ft 6 00 oO O vO <> W o rt ro O r^ I.-. \t~ so o u I ■ ■ < ■ > O J> o CO M CO o r^ M Cl o < M +j c O vO so OO o O o 01 o O ro •* Tl- O^ o u. d^ M CI CO c» 6 a. r- M CI o l/- o \r- to s :t IT) CO p p o bv M 0^ ^ o r^ •S E^ w \f H M OO M (^ 4 ^ ■!-> 1 cn so Ti- I l/- lO -* o O CO ro !>. H o \n t^ c^ CO 4 d CO r^ Cl o H 6 LO o \n \r O 6 o Y? CO M rv- -t o ^ ^ io Tf -t H o CO M \o M f- ro M -+ ^ c O o 00 vO ■^ 0) 1-* 01 lO -^ w o O • Lh H ^ CO oO 00 d • OJ r^ H (N CIh M u-> 00 o 00 CO g p c^ vy Y? 1- UTi H lO ^ ^ ^ U-, H O H 1- U-) -^ H O i-^ r~. a ) 0\ ir^ c^ o Ih CO lO Cl H H o t - GO T i- ^ i^ ^ h H H oc w H lo o ro H -+ h I (= c r c b -^ c > ) re C 1 h c ^ _a. Cl 3 s b 7^ _^ L 'c J _c _c Z aJ > (. J '-^ '^ n o L u ■< n 'S c H 1 3 ^ S T a j" _i a 3 h I , , ) C 1 ^ 3 T 1 a. r/l a; OJ )H hr cd ^ a a H (D ^ bO rTJ ul W3 3 3 -a aj 3 _o M ftl 4:^ 6 0) a "nl s e Tl '^ flJ C i; o Cl (> (H H) ft Ul fli OJ rl J3 H bn c! a •R g a ■V U-l n 1 C, *H 0) u 3 ^ rt T3 rt Mh Ti O (1) (U ^, > (U u i i ri ■M 4-> U) C nJ (U O [/J -t^ SUBAQUEOUS DRILLING 235 is without the adjustable " slip joint " for the hydraulic lift. Instead a '' swing joint/' is used and as the drill moves along the deck this joint causes the two pipes connected to jack knife (see Fig. 104). The following factors were observed in the operation of this boat: Drills No. I and No. 4 are Rand H, 69. No. 2 and No, 3, are idea of Mr. Dunbar. They have the Rand cylinder and valve and bottom head, while the top heads are the Ingersoll-Rand. Diameter of piston, 5-^-". Length of stroke, No. i and No 4, 6^", No. 2 and No. 3, 5V'. Lift, about 19'. Two chucks are practically like the U, only instead of the U-bolt there are two separate bolts with heads imbedded to prevent turning. Two U-chucks, Pressure at drill, 85 lbs. Drills run about 300 strokes per minute. Moved up and down by hydraulic lift operated by valves similar to those of the '' Earthquake." One of the pictures of the "Earthquake" (Fig. 100) shows the runner at the throttle and the mode of operation of the valves. Diameter of tip, 3V'. Hard tool steel tips. Length of steel, 35J' Section circular, if" diam. Handled by hand. Steel tempered till file will not touch. One-half inch jet used for cleaning holes, 2,390 cu.in. of water per jet per cutting minute, 71.3 cu. in. of water per cu.in. of rock cut. Worthington pump, 7X4^X6, 4^" suction, 2^ discharge, furnished water to the jets. Speed of pump, 50 strokes per minute. Depth of holes, 7'-2", average of observations. Longitudinal spacing of holes, 5'. Lateral spacing, 5'. Material, limestone. 236 ROCK DRILLING Rock fairly hard and clean. Nineteen holes shot to a row, 12 rows, or 228 holes. Pluto powder made by Dunbar Co., 60%. Sticks, iS^Xif"; weight, ij lbs. Fig. 104. — Swing Joint on "Hurricane." Fig. 105. — Feed-pipe Slide Joint. Twenty sticks to the hole. Blaster, foreman, runner and helper do loading and blasting. Four drills on boat. Two Scotch marine boilers comprise thp power plant. SUBAQUEOUS DRILLING Horse power of boilers 80 and 140. Steam pressure at boiler 100 lbs. Length of feed pipe, about 75' from main to drills. Diameter, 3'' main, 2", i^" slide joint (see Fig. 105). Plant all afloat. Size of job, 750 good working days. 237 Fig. 106. — Spud Engine on " Hurricane.'* Length of shift, 11 hours. Two shifts. Contract price, $2.80 per cubic yard for rock and 50 cts. per cubic yard for earth. Blacksmith keeps drill bits in shape, makes needed nuts, bolts, etc., and necessary repairs. Twelve tons of coal used in 24 hours = 3,000 lbs. per drill. per shift. One bbl. of drill cylinder oil used in ten days = 5-J- pints per drill per shift. i 238 ROCK DRILLING A foreman on each boat and one walking boss for the two boats. Men all live ashore. Interest and depreciation on plant, valued at $45,000, at 2% per working month, $17.30 per shift. Superintendence, one day foreman at 12.8% of daily wages, night foreman, 11.7% of nightly wages. Moving boat consumes only 1.3% of total time and costs 1.3% of shift wages, or 53 cts. per shift. This is much below the average, and due to the fact that the nature of the work (on jagged face) made drilling slow and hence resulted in infrequent movings of the boat. Moving cost per drill per shift, 13 cts. The following is a rough inventory of the equipment on board this boat : Steel boat. Four spud anchors. Four spud anchor engines. Two steam windlasses. One hydraulic cylinder. Two boilers, 80 and 140 H.P. One dynamo and small engine. One blower and small engine. One washout water pump, Worthington, 7X4JX6". Two pairs of pumps, Worthington, 12X5.^X10". One anvil. One forge. One bench and vise. One pipe clamp. One cutter. One powder boat. Two spare drills. The following figures for cost per lineal foot drilled and per cubic yard of pay rock, are based on the average performance for a period of 4 months or 204 shifts. The average depth of hole was taken as 12. 11'. The holes were drilled about 3' below pay grade and the cubic yards of pay rock are figured on that basis. SUBAQUEOUS DRILLING 239 Average over 4 months, 779' drilled per day. Average over 4 months, 390' drilled per shift. Average over 4 months, 541 cubic yards of pay rock per day. Average over 4 months, 270 cubic yards of pay rock per shift. COSTS Force. 4 drillers . 4 helpers . 1 blacksmith 2 blacksmiths' helpers , I fireman I foreman (day) per mo... I foreman (night) per mo . I powder man Rates of Wages, Standard. $3.02^ 2.42 3.62 2.42 2-75 121.00 110.00 11.7% Day shift . . Night shift . Total labor 60% dynamite 1172 lbs. at 12 cts., 2 shifts .. Coal, 12.7 tons at 3.15, 2 shifts Oil, 5.2 gals, at .40, 2 shifts Total Plant $45,000, Interest and depreciation 2% per working month Cost per Shift. tiI2.IO 9.68 $21.78 3.62 4.84 8.46 2-75 4.64 4-25 3-30 2-75 4.64 4-25 3-3^ 40.93 40-54 $81.47 140.64 40.00 2.08 $264.19 34.60 Cost per Foot in Cents. 5-58 2.18 0.70 1.20 1. 10 10.50 10.40 10.45 18.05 5-iS 0.27 33-92 4-44 Cost per pay yd. in Cents, 8.06 3-14 1.02 1.72 1.58 15.16 15.00 15-07 26.00 7.40 0.38 48.85 6.40 No account has been taken of the contractor's overhead charges, profit, cost of getting plant into operation in the spring and clean- ing up in the fall, storing equipment during winter, legal expenses, insurance, charity, etc. 60% dynamite per ft. drilled, gross 1.5 1 lbs. nitroglycerin, 0.906 lb. 60% dynamite per. cu.yd., pay rock, gross 2.16 lbs. nitroglycerin, 1.296 lbs. 60% dynamite per cu.yd., blasted, gross 1.63 lbs. nitroglycerin, 0.978 lb. . ratio cu.yds. blasted ^^ ^ cubic yards pay 240 ROCK DRILLING The following is a general summary of data on file in the gov- ernment office at Amherstberg, Ont., obtained with the consent Fig. 107. — Drill Boat *' Hurricane." of the contractor. The items marked * are deductions from the data on file: May. June. July. August. Shifts worked Hours worked Hours delay Number of holes * Number of holes per shift Lineal feet drilled Depth of holes Dynamite, 60% Coal, tons * Feet per day * Feet per drill hour, working " " including delays... Feet per man hour Labor per day, dollars * Labor per foot drilled, cents * Coal per foot drilled in pounds . . . . Coal per cubic yard pay rock, pounds * Cubic yards pay rock * " " perdav *= " " " shift, II hours.... 48 481 44 1,644 34 20,643 12.56 18,517 308 860 10.72 9-83 2.79 81.47 9.48 29.6 42.2 14,580 607 304 52 551 21 2,165 42 22,929 10.59 29,926 328 882 10.41 10.03 2.86 81.47 9.24 - 28.6 43-2 15,160 5S3 292 52 561 II 1.505 29 19,603 13.02 37,865 754 8-75 8.58 ^•45 81.47 10.81 33-8 47.6 r3>97o 538 269 52 557 15 1.317 25 16,139 12.28 33,219 327 622 7-25 7.06 2.02 81.47 13.10 40.5 58.0 11,320 436 218 subaqup:ous drilling 241 < u O I— I Q ■ t/i M 0\ LO 0\ Cl cfl 71- W ►H '.0 9. M « Cl N a \j'. 'O ■!*■ 10 (A PD M OS CO CO 0-. > 1-1 M p p. 9. -t ai < ^ CO M HI ci ''t IH M a CO -t- > < - (6 l-O 00 Os -t Cl a q C4 d W Cl LO sg tT) W ro 06 cq n ■ w 10 10 ijO U-, K c-j ^ ■* M IH ro t/i rt . ■ s e LO CO ro -1- 'i o X (/) w 10 t-l CO > > '^ r? rt IH -^ d cxD Cl H ci ^- 6^ E Cl £ d " lo LO -t ;^ CO ro :t 9. CJ ^a fO M ^ b 1-1 Cl sqO -oisi LO ly, 10 IJO 1/-, LO LO , K ''' r? M CO Cl LT; Cl en cd sg CO C] Cl Cl ro -t O M w \n ^ Ti- Cl ro > > IN H p fO ^i M M N ro cio CO ro t^ ■ ui r-^ lo Cl fO d M r? r? r? "ri p 6 3e vO b b M ro Cl IN ro ■^qo ■'^N .r-. '^, T -t Cl ■ o; 10 LO u~. ir. :t P. M M Cl '■4- t-1 <-. g LO NO o , "i Cl ro CC Cl i-O Pi > 10 r-o -t 10 Cl 01 D < r-- ■"O b b M CO o a -t LO Ph „ - i^ Cl 10 r-^ cs d TJ- W W p c^ r? 6 Sg Cl 8 8 H ro bs Cl ■yqO OM ^<- 't -t -^ M ! ! fi w ^ a p rt rt p p N W J-- b M CO Os M 1-1 "", C-^ O . oi On <^. 00 Pi >■ 10 !? p Cl Cl M ^ ^B cK b w Cl U-) On o to -t \^ • ui CI i-T .a Tf r? r? rt P. Cl tc d 12; ^g r^ b b H ro ro ■5 M ro 4-1 •sqo OJ^ -1- Tf -t- ^ t 1 , oj >H he hole. into n. . . (3j : Finishing hol Waiting fo loading gan < C u Loading Getting positio c " "^ H u5 t! 2 B T3 1J -«-> £i ^ &" s. -^ ^^ O" 3 c o -- .S o • S F^ d ° faO ■r! (u .■!:; . "^ O o _, _c ^ 242 ROCK DRILLING < u I— I C4 . ly^ \j-> \o 1^ , ai ^ H ^ . 'o\ ^ ^ r^ ^ 1 3 ■^6 vo yD M " 1 o 1 O U-) ij-1 O g I-. o n ID w LO ir 1 r^ ro PJ CQ C 01 06 1— ( ^e 0\ H H 1-1 , r-i U-l H CO o « rt r? rr ^- ^ M ^ 1^ OC CI •^ o ^ CI o un ' ■* 0^ in A '^ ^ (N C5 (S~ p CO u 1 -a . OO ON 03 ^ M On O ^S O (N ON M o o -t -Tt GO H 'i'^ ri" n u- r^ > o M ■* -1 CC I- sb ^6 u-", M r-~ tm w U-) w ^ « rr- 6 d w O i-< c C -i w ^ 0) ■ b M l_, Ci Jv ^ 06 ^^ ro CO . t/i o ^ n p (/] P^ ^ . ■i *+ ^ CD 3 "-■s "* o \i -i i-- O If 1/ ■^ b ^^ t; 1- o c LT oi M \J I-. liO ui _aj CO CJ y? P :^ W T) . w. C \ -i- -^ ■ CO O ^H c 1 -+ u CO c C C 00 rt ^ M c c u ~> w O O C N W Z S h- r- ^E u "l c On to w C h CO C c or d ■ OJ t IP ^C 5 4 rt X _c ■ ~ h p •£ T p 3 1 • 'Z c J .S2 T? t • ^ c ; ^ ■ h ^ 2 . ; ' ^ c : 1- t 3 i 5 i H C 3 "S 3 ,c E t -1 F- 3 e 4 iH < i) .E 3 c ^ _£ 2 ^ 3 c 3 ^ 3 J 5 c \ I J 3 5 P 5 c J ^ 1 _ o in,rt-^ f^ +J ^g'?. U OJ -r; ■^^^ ^ «^ ^f 0) OJ oS-^ ^ -^ -l-f .Sc i^n (fl -*-• c? - 1J — • a bort sS>o !U C a aJ w ^ ==^ ^ 'P (U ^T.^ X U *"* !;i^-^ (U C 15 «J 06 bo ^ fi , uired conds worki "a . a* > > ^ d d d The ing h time -^SSM ^^h^ > ij SUBAQUEOUS DRILLING 243 < O P^ O I— I u 1 ro ■LTi o> CO t>. M CO « w CI -* H rt od in H H CM « H < -4-^ g 1^ ro On o c^ 1-n o M H 0^ H W, l~- o u Ti- I^ o '^ fj l/- o ro H ^ NO o 6 Ph % o un ly U-) u-> 'O 1 aj r<^ O ■;t H o V? fi C>6 c> ■^ t^ ^ lo fO 1 H H o 1^ H HI NO o 4J (N CO O ^ O o O H 0^ CI NO o o c- 4 r^ -^ j>. o 1 Ih ■^ tH « LO O 1 , <0 H rO fL. d ^ CO On O o p On !>* 1 CJ O r? P. r? p O ■ - S NO CO '^ w On ro On 1 H t^ On H H HI H ro O _jj r^ -o w U^ ro O ID H !>. ^ ■^ OO o o On H 1-1 t-* d o Ld r^ HI - H - o ly T M o oj 1- LO O ■^ h ;i- p 1 6 r^ ^ ■* C •:i ci o P On 'd- c ■& 1 u - , F n ' S 5 "^ > 1 > c. > ^ c J i ^ 3 '^ <*■ : '^ 3 'B <^ > -» > -^ '? J , ' •—! 1 •— 1 n ;K J '■ i ^ i rt a t, 5 •'c ■> u ! 1 'c 1 S : c 3 o y- 3 P ; p 1 f= 3 ^ H ^ ^ .S H ^ 'C :3 i.g c 3 1-, t/i 1 . rl) u ■^ e ^ w >H f^ n ^ 11 ^ -d ■♦-' . CO W -f -t >-J o d ai UO lo o O S6 LO O Cl lO LO io O O PI p u CO c/: — — „ c " to o -LT, o O N w Tt ?9 7t p Cl 6 ^e ° -1 H o o Cl GO fo ^O VD VJD \r O o lO li-1 \r ■> LO c3 u u lO ^ M Y? to ;^a M CO o -t -t- -t ^ o ^-" o c lO \o \f 1 vn p Tt r? c lo > Id M lo o Cl o c :i O CO M i^ o O lO O in H c " p P p H ir ~t (O 6 ^d H H H O W M Cl ^ ■ ui So C^ li-1 lO lO ir 1 ■£ Cl. bO bO ^ 0) d .2 o' <4-< -rt O B tn CU T) :3 to C! t^ d S ^ a 1-1 X! t+-t O J2 O S en > P x; o c d •■"" o r«l C fl) o JU f^ H 262 ROCK DRILLING O < o 1-1 I— ( Pi Q O < Ph . tn o o c ) o lo o M P i^ O m t/} _aj (J p (. M c J-; rp H -t H o o ^ c lO ^o r^ hJ ON (N 1 O ^ Efl o O Lo O u "1 O C o >^ M Cn r9 9. c (.-^ p .9 i-> o ^ p. ^■ ro c ^ C o o C/J H O 6 \J-> 1^ c lO c >n lo lo ^ p -t- fO ro O rt P V? H 00 c O ^ ^ tn ro CO -* c u c c o M -1 rp H 1- o c On 6 r* 1 c ^O LO •) o c o X ■^ p r? 9. v T 01 p p p ^s CM Cs m Ln 1- c c?5 lO 00 6 lo C LO C LO U-) t lo m C p c o LO o f 1 w u C p 'q 1 1 c w JH (U !fi ^ O-TD ^ ^ c t-i l-^rt ^ ■5.2 J oj ca 01 t3 - ^^ ^ ':: ^ t:3 .S (D bO '41! P- ri O 2 -^ ^^ .H c -i^ -^ h OJ ni bO t 5 nl (T1 Ih i-i (U dj > > rt d (D 0) ^ J3 HH SUBAQUEOUS DRILLING 263 o < o pq hJ I— I Q O < PQ CO cq O r^ CO r i oc t^ lO M ■o - ID > J vO W c O- ro 1 O 1 vO w ^ \ o 1 J^ O 1 O 1 Q Ln tn 0^ C) ^- 1 1 >-• CO o 4 H d O ly^ If 1 in a ro CO H Vf 1 w ON 00 SO J>. M M H rO cs -d 00 CH w ID ■^ so o o MD o lo O ro O O Tt u O o H p l:^ r^ O N d 6 S3 fin vO w r< i o \r^ xn o xn XT 1 \n 6 w M -t M V? r C li-) f^ \0 w O y- H o (N On rv 3 rO O PI lO -Tj- .l:~~ j> O o ir> ri- 0\ - s vO ci r' ) o 6 ^ O u^ O xn o o B Cl r9 H O CN b (N o l:^ \0 so '^ oc M 01 \^ o N f^ " O] Tf O VO O so o yD J>^ 00 00 rr 3 O U vo H O M d •j-) cr. -t o M 6 o lO o u- -i in B r; fO w O 01 -f o Tt ir ■i >o H vo o CO so M !N c/ c ;* b 3 1 u c b ! 1 ^ 5 c J -C 'c ) b 1 c 1 n : 3 t 1 C JJ b 1 _c D T I 3 a 3 a. ' 4 * t- f 1 1 « P 5 ^ H O d ■5 .a " bn ^ G t3 QJ j_, 411 tn O in (U H OiJ o 2 xJ (U bb *^ ^ o •^ u O 3i oj bO ■5 M^ .S o C S -5 o ^ i a -O ^ 57o * Number of holes per shift 30 Depth of holes, feet 10. i Lineal feet drilled 15)850 Dynamite used, 60% lbs S'^,743 Coal used, tons 2 18 * Feet per day 610 * Feet per drill hour, working 7.20 * Feet per drill hour, total 6.94 * Feet per man hour 2.25 Labor per day $81.47 * Labor per foot drilled, cents 13.3 * Coal per foot drilled, tons 0.0137=27.4 lbs. * Cubic yards pay rock 9,800 * Cubic yards per day 376 * Cubic yards per shift, 1 1 hrs 1S8 * 60% dynamite per lineal foot Gross 2.00 lbs., nitroglycerin 1.200 lbs. * 60% dynamite per cubic yard pay rock, Gross 3.24 lbs., nitroglycerin 1.944 lbs. * 60% dynamite per cubic yard blasted. Gross 2.40 lbs., nitroglycerin 1.44 lbs. cubic yards blasted Ratio — — —-=j,'2t, cubic yards pay rock Buffalo Drill Boat No. i. Observations 1909. The second of the Buffalo Dredging Company drill boats working upon the western 100' of section No. 3 of the new Livingstone Improve- ment of the Detroit River is the so-called No. i. Built some twenty years ago by the Heman & Wood Co. of Buffalo, it is one of the oldest drill boats of this company. Inconvenient and antiquated as it is, it still has one excellent feature, which is that the steam feed pipes and the hydraulic lift pipes for each drill are practically out of the way, being for the greater part of their extent upon the roof of the boat (see Fig. 122). This 270 ROCK DRILLING Fig. 121. — EulTaln Boat No. i. Fig. 122. — Swing Pipe Joints on Roof of Buffalo Boat No. i. SUBAQUEOUS DRILLING 271 boat was rebuilt during the summer of 1908, but is still essentially an old wooden craft. Spud anchors, capstans, and mechanism for moving the frames along deck are all operated by hand, and so their operation is very slow and inconvenient. It is 82Y long and 25' wide, and has a wooden house 63 -J X15-I' that covers all machinery except the three drills, capstans and mooring posts. The hull is of the regular wooden scow type construction, and the following description, although especially applicable to the interior bracing of this boat, will give a good general idea of the arrangement of all such types of wooden boat. Spaced 72'', center to center, are 12X12'' floor beams running transversely. Alternate ones have wooden knee brackets on their ends and the others have vertical posts. Side planking is secured to these vertical posts and the vertical side of the brackets. Running lengthwise of the boat and resting on the tops of these vertical posts and the top of the vertical member of the knee are two 6 X 10" timbers, one on each side. Running across these 6 X 10" members are the rafters 8X4", and spaced 72" for the deck planking. Bolted to the 12X12" floor beam members on their londer side are 12 X12" stringers spaced 24" center to center that run the full length of the boat and to the under side of which the bottom planking is secured. At the ends of these are posts to which the end planking of the scow is attached. The boat is divided into four compartments by longitudinal partitions of 5' timbers. These are by no means water-tight, but they simply stiffen the boat and furnish additional support for the deck rafters. It may also be added that between the 12X12" floor beams to which the 12X12" longitudinal stringers are attached are 12X4" timbers running across the boat, whose only function seems to be to furnish additional transverse stiffness to the boat. Into each of the longitudinal partitions are cut holes 2X2' to afford access from one compartment to another. The boat is equipped with three Ingersoll-Rand drills, Type H 61. Each frame has a range of 6 holes, their spacing along deck being 4'. Running along the deck are two 25-lb. rails upon which the frames slide. One of these rails is near the oiiter 272 ROCK DRILLING edge of the boat and the other about 3-2-' from it. Upon the deck midway between these two rails is a rack 5" wide into which a 5" cog wheel meshes, secured to an axle in the frame of each drill. This cog wheel is given the necessary rotary motion by means of a crowbar in the hands of the driller and his helper. The steel bits used in drilling average 33' in length and some 400 lbs. in weight. The upper half of the bit is 2" steel, circular section, and the lower half 2-J". The point of the bit is of hard octagonal tool steel, 24" long and 2 V' in diameter. When sharpened and ready for use the bit is 4^" across and this shape: +. These bits will usually dig 15 holes without repointing, but of course accidents frequently happen, causing much more frequent sharpening. When the steel, for any reason, has to be changed, the handling of it is by hand up to the point where the workmen shove its end into the house. Here a hook fastened to a small trolley that slides on a suspended steel bar 2X-|-" assists, and for the same purpose there are also two blocks and tackle. This boat is also equipped with the mud pipe as described on No. 5, but its section is so small that before a drilled hole can be charged the bit must be released from its clutch and drawn up by hand till its end is clear of the pipe. This is necessary, because there is not room at the same time for both charger and bit. The time consumed to thus take out and sling up a bit preparatory to loading is 5 min. Drill Data. Type of drill, Ingersoll-Rand H 61. Diameter of piston, 5^". Stroke obtained, 7". Lift, about 18'. U-chuck. Steam pressure, 100 lbs. at boiler. Speed of drill, about 300 strokes. The drills are raised in their frames by hydraulic lifts, the feed pipes of which are for the greater part of their length on the roof of the house covering the boat. Bits have hard octagonal tool steel points, 4^'' diameter. Drill steel, circular section, 2 and 2^''. Steel handled by men with the aid of a hook fastened to a SUBAQUEOUS DRILLING 273 small trolley that slides on a suspended steel bar, section 2Xy. There are also two blocks and tackle whereby the steel can be more readily handled. Steel tempered till file will not touch. Three-eighths inch water jet cleans hole. Worthington pump, 12X5JX10" furnishes water to jets. Speed of pump fluctuates when the machines are raised or lowered. Water pressure is 425 lbs.; but dare not turn on full. The washout pipe has 5' of f" pipe, reducing to 14' of \'\ which in turn reduces to 10' of |". A rubber hose \" in diameter forms a flexible coupling between the f" pipe and a i" feed pipe. Holes are about 6' deep, and 5^" in diameter. Longitudinal spacing of holes, 4'. Lateral spacing of holes, 4'. Generally a washout pipe is not used. However, when one machine gets behind it is enabled to catch up by means of the washout water. Material drilled is limestone, with about 2^' of sand on top. Streaks of hard rock. Holes blasted 26X18 plus 24 = 492; 26 rows of 18 each, plus 24 extra ones for closer spacing on outside rows. Potts powder used, 60%. Sticks of powder are 2X8" and weigh \\ lbs. each. Twelve sticks are used per hole. Use a blasting machine, but have a dry battery in reserve for firing holes. One blaster and foreman, also runner and helper do the blasting. Three drills compose the outfit. Oswego marine, 2-fire boiler. Gauge pressure at boiler, 100 lbs. Length of feed pipe, about 50', from steam chest to main. Diameter of main, 3". Length of contract, 750 good working days. Ten-hour day and 12 -hour night shifts are worked. Two shifts. 274 ROCK DRILLING Day shift: 3 drillers at 3 drillers' helpers at 1 blacksmith at 2 blacksmiths' helpers at 1 fireman at I foreman at ®i2 1 per month I blaster at 02| = $9- 42 = 7- 62 = 3- 42 = 4- 75 = 2 . 65 = 4- 30 = 3- 07^ per shift 26 62 84 75 65 per day 30 per shift Total = $3 5 ■ 49^ Night shift: 3 drillers at $3.02^ = 3 drillers' helpers at 2.42 = I blaster at 3 . 30 = I fireman at 2.75 = I foreman, $110 per month at 4.25 = $9.07^ per night 7.26 3.30 '^ 2-75 " 4.2s " Total. = $26.63^ '' 35.49^ da}' shift $62 . 13 both shifts The contract price is $2.80 per cubic yard for rock and 50 cts. per cubic yard for earth. As said before, each drill bit consists of three parts. The blacksmith has to make all these welds and keep the bits sharpened and in shape. Eight tons coal used per 24 hrs. = 2666 lbs. per drill per shift. Ten gallons of oil used per day =13^ pints per drill per shift. The coal is bought at the Amherstburg dock. It is loaded by clamshell buckets into square dump boxes. These dump boxes are placed in four rows on board a scow. In the center of the scow, on the deck, and between the buckets (two rows on each side) there is a track on which a crane moves back and forth. A tug takes the scow and its load of coal boxes out to the drill boats. Then the crane Hfts each dump bucket by its bail until it hangs suspended over the coal chute in the roof. Workmen then release the catch on the dump box and it empties its coal into the bunker. The scow carries enough coal on one trip to supply the four boats of the Buffalo fleet two days, making a trip every other day (see Fig. 120). SUBAQUEOUS DRILLING 275 Coal costs $3.15 at the dock. The company owns its own tug and considers the cost of handHng to be nothing. If this work had to be paid for, handling would cost 35 cts. a ton. No figures are kept as to repairs. Each boat has a day and a night foreman, and besides a super- intendent for the four boats. Day foreman at 15.1% of the day wages; night foreman at 19% of the night wages. Men live ashore. Interest and depreciation on the plant, valued at $25,000, at 2% per working month = $9.61 per shift. A rough inventory of the equipment is given below: Boat, 82^ wooden scow type hull. One cutter. One powder boat. Three mounted drills and equipment. One spare drill. Four spud anchors. Two hand windlasses. One forge. One anvil. One marine boiler. One injector. One auxiliary boiler feed pump, Hughes, 4JX5. One Worthington pump, 12X5IX10", 425 lbs. Eleven drill steels. One bench, vise and pipe clamp. One acetylene gas outfit. One feed-water filter. One closet. The following figures for cost per lineal foot drilled and per cubic yard of pay rock are based on the average performance for 14 days, or 28 shifts of 11 hrs. The average depth of hole is taken ^s 5-37'. The holes are drilled about 1.37' below pay grade and the cubic yards of pay rock are figured on that basis. 276 ROCK DRILLING Average for 14 days, 468 lin.ft. drilled per day. Average for 28 shifts, 234 lin.ft. per shift, assuming equal shifts. Average for 14 days, 206 cubic pay yards per day. Average for 28 shifts, 103 cubic pay yards per shift. COSTS Force. Rates of Wages. Cost per Shift. Cost per Foot in Cents. Cost per Pay Yard in Cents. 3 drillers - 3 drillers' helpers I blaster I fireman I foreman, $121 per month, 1 blacksmith 2 blacksmiths' helpers I foreman, $110 per month.. 12 men, day shift . . 9 men, night shift . $3 .02^ 2 .42 ^.-^'^ 2.75 4-65 3.62 2.42 4-25 15-1% 19-0% Total labor Plant at $25,000, interest and depreciation at 2% per working month 60% dynamite, 1155 lbs. at 12 cts Coal, 8 tons at $3.15 Oil, lo.o gals, at 40 cts Total . 9.07^ 7.26 2-75 4-65 3.62 4.84 4-25 3. as 3.10 1. 41 1. 17 1-99 1-55 2.07 1.82 $35-49^ 26.63^ 15-17 11.38 $62 . 13 19.22 138.60 25.20 4.00 13.28 4.11 29.60 5-40 0.85 $249.15 53-24 S.S2 7-05 3.20 2.67 4-52 3-52 4.70 4-13 34-48 25-87 30.18 9-34 67.20 12.25 1-94 120.91 The following is a summary of the record for this boat for the last two weeks in August as found in the government office at Amherstburg, Ont., used with permission of the contractor. The items marked * are deductions from the data on file. Shifts work 11 hrs 28 Hours worked 298 Hours idle 10 Number of holes ij2 19 * Number of holes per shift 43 Lineal feet drilled 6,555 Depth of holes, feet 5.4 Dynamite, lbs., 60% 16,960 Coal, tons 112 * Feet per day 468 * Feet per shift 234 *Feet per drill hour, working 7-33 *Feet per drill hour., including delays 7. 10 SUBAQUEOUS DRILLING 277 * Feet per man hour 2 .02 Labor per day $62.13 * Labor per foot drilled, cts 13.3 * Coal per foot drilled, tons 0.0171 = 34.2 lbs. * Coal per cubic yard pay rock, tons 0.0388 = 77.6 lbs. * Cubic yards pay rock 2,890 * Cubic yards pay rock per day 206 * Cubic yards pay rock per shift 103 Cubic yards of pay rock are figured as follows: Holes are 5.37' deepj 4' of which depth is pay depth. Spacing is 4 X4'. Number of holes 1219. 4X4X4Xi2i9 = 78jOoo cubic feet = 289o cubic pay yards. * Dynamite 60% per lineal foot, Gross 2.59 lbs., nitroglycerin 1.55 lbs. * Dynamite 60% per cubic yard pay, Gross 5.87 lbs., nitroglycerin 3.52 lbs. * Dynamite 60% per cubic yard blasted, Gross 4.37 lbs., nitroglycerin 2.62 lbs. Cubic yards blasted * Ratio =^i-34 Cubic yards pav rock CHAPTER XIII SUBAQUEOUS 'DRlLl.mG— Continued Improving Black Rock Harbor and Channel at Buffalo^ N. Y.^ The Buffalo Dredging Co. and Empire Engineering Corporation are engaged upon this work of improvement; 350,000 cu. yds. of material are to be removed. Of this 22%, or 81,000 cu. yds., is sand, gravel, clay and boulders, and in addition there are 269,000 cu. yds. of limestone and fiint bed rock. The flint is very hard material to drill and difficult to blast. For the latter reason the 3' 6" holes are spaced very closely together (3X2'). In the limestone the spacing is 6X5' and depth 10' 9'^ and 9' 9"j all holes being 3^^ Monthly estimates are made by scow measurement in order to get a rough idea of the amounts due the contractors. At the end of the season accurate surveys are made and errors corrected. The new channel is to be 2^^ deep and 4020' long by 200 to 240' in width. The contract price for rock above 23' grade is $2.70 per cubic yard. Holes are drilled 2' below pay grade. The following data and deductions are kept in separate columns for each different depth of hole. Special attention is called to the enormous increase in unit costs for the short closely spaced holes in the flint bed rock. ^ Data collected by Mr. Gilbert H. Gilbert. 278 SUBAQUEOUS DRILLING 27^ Fig. 123. — Black Rock Harbor. fl Fig. 124. — Black Rock Harbor, Buffalo. Empire Engineering Corporation, 280 ROCK DRILLING Five IngersoU-Rand drills, 6Y'. Material, limestone and flint bed rock. Bed rock holes, 3^", drilled 2' below pay grade. Depth 10' 9"- 3' 6" Shifts worked, 11 hrs.. Hours worked Horns delay Number of holes Lineal feet drilled Cubic yards pay rock. Dynamite, 60% lbs . . . Coal, tons Labor, per shift Lineal feet per shift Lineal feet per drill hr., working. . Lineal feet per man hr Labor per foot drilled Cubic yards pay rock per shift. . . . Cubic yards pay rock per drill hr. , Labor per cubic yard pay rock... Coal per foot drilled in lbs , Coal per drill per shift, lbs Dynamite per lineal foot drilled . . . Dynamite per cubic yard pay rock Dynamite per cubic yard loosened. Total cost per lin.ft. drilled exclu- sive of dynamite and explod.,cts. Total cost per cu.yd. pay including all items before listed, cts Same per cubic yard blasted., cts. . Spacing of holes. Ratio cubic yards blasted to cubic yards pay 28^ 298 IS 532 5726 5180 Gly. 4014 lbs, = 66go 114 $46.38 201 3.8s 1-3 23.09 182 3-3^ 25-43 39.80 1600 1. 1 7 lbs. Gly. 0.70 lb. 1.29 lbs. Gly. 0.77 lb. 1.05 lbs. Gly. 0.63 lb. 38.26 61.99 50.40 6'X5' 1.23 52 552 22 1,678 15^224 14,450 Gly. 11,172 lbs. = 18,620 208 $46.38 293 5-51 1.62 15.85 278 5.06 16.68 27.30 1600 1.22 lbs., Gly. 0.73 lb. 1.29 lbs. Gly. 0.77 lb. 1.03 lbs. Gly. 0.62 lb. 26.26 50.01 39.70 6'X5' 1.258 22^ 232 15 999 3480 333 Gly. 2 58 lbs. = 430 90 $46.38 154.5 3-0 0.924 30.16 14.8 0.269 313-50 51.S 1600 0.12 lb, Gly. 0.07 lb. 1.29 lbs. Gly. 0.77 lb. 0.55 lb. Gly. 0.33 lb. 49.90 557-30 239.00 2'X3' 2.33 Note. The difference in cost between the 10' 9" and 9' 9" holes is due to variations in the hardness of the rock. The large increase in cost per lineal foot of the 3' 6" holes is due to hardness of material and the enormous increase in cost per cubic yard pay is due to the small yardage per foot drilled due to close spacing of holes. The following figures for cost per lineal foot drilled and per cubic yard of pay rock loosened are based on the average perform- ance as follows: SUBAQEUOUS DRILLING 281 ^ -s -^«J 't -^ HtN U-: M (N H . N /— '^^ -t-> W O tr; -q Q OO ro '7] "^ a -o fO a^^ t3 .^^^^ O ^ =" « UN «J In XI P, QJ ^, H 1-1 r-) OJ t, JJ U K o Z- &4 H P S V -*) O 00 O O J3 cs 00 « , lo lot; C OJ IH (L) U (U rt OJ •-::; '^ n '^ ^ d O O O O O o c O O o o o S O W roo ■* lo fo C ^ r- M lO (O r^i Q T r^ M 00 1- - fO li-ivc tlTO 1- fo "t r- 00 in N -> ro 1 H 00 - M fO lO O 1 >^l ^ fO ■* t ' H 1 ., O 1 1 1 fj N 00 Ttw 1- 4 (O »« c OO Tf 1 o r- 1 r~| 1) vO 't M I-. O 1 wxC 00 -* h - -q- 0\ n "o r- 1/1 N M ro [ 00 i- Oi fo O 1 fO 0\ 1 ro| ffi C^ ^ " fO fO r r d 1-21 t 0> CM- 0\ fO C N >- J "o t f- u 00 M 0\>0 ■O lO C ^ M u^oo 1 ^ Qi 1 fO[ Q (> roM O ■- \o' -T C M O* 1 n m 1 cG 1 ; " • 1 1 V pJ-E'S D ■^ M M b T fo M r M »o O lO -T 1 CM i? OS O 00 m I. o -t a> n ■J r- «~" iJi r O. Q T ^ M M p ino 1- PO 0> O ro 00 1 H 1 "o> M ro H- r ■O ~6 !s 1 1 Sol VI M Tf (-, V 00 r~ '^ r o> o w « -o »~- 1/) W \0 fo f 4 M M r T (J n IS IJ^ fO l~- V3 \0 25.5o 10.50 2.20 63.8 26.2 5-5 343-7 141-5 29.6 Dynamite, 160 lbs. at 15 cts. Exploders, 10 at 3 cts ^3^.20 24.00 0.30 95-5 60.0 0.7 514-8 323-5 4.0 Total drilling and blasting Interest and depreciation at 2% per working month on plant estimated at $10,000 $62 . 50 7.70 156.2 19-3 842.3 103.7 Total. 175-5 946.0 Labor per day, 10 hrs, dollars 25.50 Lineal feet per drill hr 2 Lineal feet per man hr 0.445 Labor per foot drilled, cts 63 .8 Cubic yards pay rock per drill hr 0.37 Cubic yards pay rock per lineal feet drilled 0.185 Labor per cubic yard pay rock $3-44 Coal per drill per day, lbs 3000 Coal per foot drilled, lbs 150 4 lbs.= 2.4 glycerine 21.6 Ibs.= i2.g6 glycerine 5.4 lbs. = 3.24 lbs. glycerine Dynamite, 60%, per foot drilled, Dynamite per cubic yard pay rock, Dynamite per cubic yard blasted, cubic yards blasted Ratio = 4 cubic yards pay Cost of drilling and loading but exclusive of dyna- mite, exploders, interest and depreciation I0.955 Total cost per cubic yard exclusive of interest and depreciation $8,423 Total cost per cubic yards including interest and depreciation $9,460 CHAPTER XV SUBAQUEOUS DRILLING BY THE PLATFORM METHOD Submarine Drilling. The platform method, for use in rough water or where there is much rise and fal in tide, was devised and developed by Mr. W. L. Saunders. This method has been successfully used in overcoming the more formidable obstacles to the removal of submerged reefs. These obstacles are (i) sand, mud, or gravel overlying the rock; (2) swift currents; (3) rise and fall of tides; (4) rough water and high winds; (5) danger of collision with passing vessels. The plant consists of a floatable platform provided with spuds by which it is elevated above the surface of the water. Tripod drills are mounted upon A frames or platforms to facilitate moving about the platform. Cylindrical telescopic tubes with a conical taper are fitted with an ejector attachment; these tubes rest on the rock, the upper end being above the surface and guided by trunk ways attached to the platform. Drilling, wash- ing, and charging are performed through these tubes. The boiler, smith's shop, pumps, and diving apparatus are carried by a barge or scow moored to the platform and by anchors. In the operations, preliminary to drilling, the telescopic tube is lowered to a bearing upon the bottom. Through the action of the hydraulic ejector, fitted to the lower end of the tube, the loose material overlying the surface of the rock is removed from the inside of the tube, permitting the tube to sink and rest upon the cleaned surface of the rock. . The drill bar is then lowered into the tube and connected to the drill placed over the mouth of the tube. The conical form of the lower end of the tube guides the steel and prevents "stepping." The progress of drilling is very materially improved by the introduction of a ij" pipe, carrying 299 300 ROCK DRILLING water, under pressure, into the drill hole and alongside the steel while the drill is in operation; a jet of water is forced to the bottom of the hole, removing the cuttings. It is no exaggeration to state that the removal of the Hell Gate rock, had this method instead of undermining been used, would have been accomplished in one- quarter of the time and at one-third of the cost. The following is a report of the operations on Black Tom reef, New York harbor, where the platform method was used. Operations were commenced May 2, 1881: Actual working days 344 Lineal feet of hole drilled 17*658 Number of holes drilled 1)73^ Number of holes blasted i>542 Average depth of holes 10.17' Average distance between holes 4' Area drilled over 32,100 sq.ft. Rock removed Sy'^3^ cu.yds. Dynamite used 20,461 lbs. Exploders used 1)844 Number of drilling machines used 3 Number of steels used (octagon ii^") 18 Longest steel used 28' Shortest steel used 16' Largest diameter of bit 3I' Smallest diameter of'bit 2^" Average depth drilled to each dressing of steel 9' Average loss of gauge per ft. drilled, ins 0.03 Total loss of steel by abrasion and dressing 59^' 394.5 lbs. Greatest number of lineal feet drilled in one day 169 Expenditure for coal, 200.2 tons $823.03 Expenditure for water ^S^o-SS Expenditure for hose $491.18 Connecting wire, 77^ lbs $52.08 Rubber tape for connections, 7 rolls $12.25 Expenditure of steel for each lineal foot drilled 0.36 oz. $0.0032 Explosive used per foot drilled, 1.16 lbs $o-53 Rock removed per foot drilled 0.29 cu.yds. Cost per lineal foot drilled, labor $0.52 Cost of coal and water, per lineal foot drilled $0,075 Cost of repairs to plant per lineal foot drilled $0,089 Cost of repairs of drills per lineal foot drilled $0.0053 Cost of repairs of ejector pipes per lineal ft. drilled . . $0,015 Cost of hose per lineal foot drilled $0,028 Cost of wire and tape per lineal foot drilled $0,004 Average total cost per lineal foot drilled $1.27 Average cost per hole charged 13-82 Average depth of hole drilled to each cubic yard of rock removed 3*44 Im.ft. SUBAQUEOUS DRILLING BY THE PLATFORM METHOD 301 Average cost of explosive per cubic yard removed, 3-98 lbs $1,84 Expenditures in steel per cubic yard removed, 1.22 oz $0,018 Cost of labor per cubic yard removed $1.79 Total cost per cubic yard, drilled and blasted $4.37 Cost of plant, including alterations and additions : Barge No. 4, hull and equipment $6,640.00 Drill float No. i 4,095.70 Drill float No. 2 4,987.40 Storeroom account, including repairs, altera- tions, coal and water, costof machinery,etc 5,663.49 $21,386.59 Expenditure in labor $9,203.88 Expenditure in explosives 9,461.00 18,664.88 $40,051.47 Cost per cubic yard of total expenditure $7-79 Operating Expenses. Labor $9,203.88 Explosives 9,461.00 Actual repairs to plant ^)5 75-57 Repair to IngersoU drills 93-31 Steam and water hose 491.18 Repairs to ejector pipes 267.54 Wire and tape used 64.33 Coal and water 1,323.58 Operating expense $22,480.39 Cost per cubic yard. 4.37 Pay roll per day $26.76 Coal per day, 0.58 ton 2.39 Water per day i .45 Explosive per day 59.48 lbs 27.50 Daily repairs to plant 4.58 Drill repairs per day 0,27 Loss of steel per day, 1.15 lbs 0.16 Repairs on ejector pipes per day 0.78 Loss in hose per day 1.43 Loss in wire per day 0.15 Loss in tape per day 0.03 Average cost per day $65.50 Average cubic yards per day i4-93 Average cost per cubic yard 4.37 Many items in this report, notably the cost of plant, are very much higher than need be. The prices given include all 302 ROCK DRILLING the experimental work done prior to the introduction of the improved methods of operation. The rock was situated in New York Bay, near Bedloe's Island. It was of granite formation, ranging in texture from soft muddy pyrites to a hard mixture of hornblende and quartz. The surface was covered by a deposit of mud, sand, and gravel, which at first interfered with the progress of the work to such an extent that but little headway was effected. After the use of the ejector pipes no further difficulty from this source was experienced. CHAPTER XVI HINTS AND SUGGESTIONS FOR ROCK DRILLING AND BLASTING Hints in Drilling and Blasting Work. Cultivate the habit of learning new methods from published accounts and then do not wait to see them used, but apply them yourself, even if you have to devise some details which were not described. The man who avails himself of published data becomes a cen- tenarian in experience before he is thirty years old. Foremen are generally men of some considerable force of character, and they are instinctively opposed to "new-fangled ideas"; consequently their opposition to improvements reflecting, .as they think, upon their own perfection, is long and bitter. One of Gilbreth's rules: No superintendent, walking-boss, engineer, timekeeper, or other employee is permitted to give an order direct to any workman, except in case of great emergency. Not even a member of the firm is exempt from this rule. The foreman in direct charge of a gang is the only man permitted to instruct his men what to do. He is the officer in charge, and his superior officers must not intentionally or unintentionally de- grade him in the eyes of his men by issuing orders over his head. The timekeeper must not gossip on the work. It is a sure cause of dissatisfaction. The men should know as little of the poHtics of the work as possible. Dissensions at headquarters are bound to affect the men and their work. If unity is lacking in high places it will also be lacking lower down. Do not let the executive do any avoidable detailed work. It may be economical to pay higher wages than the prevailing rate. This attracts the best class of labor. Men will do io% more work for 5% more pay. A cut of 10% in wages may mean a reduction of 20% in output. 303 304 ROCK DRILLING To avoid demoralization, pay must be paid promptly on regular pay day. No matter how sure the men may be of their pay, failure to meet them on pay day affects their work badly. Gilbreth requires all monthly men or steady pay men to arrive on the job before the first whistle is sounded and remain on the job until quitting time, regardless of weather. All sources of dissatisfaction should be immediately and impartially investigated, and the men must know that although they are responsible for the quantity and quality of their work to the immediate foreman they are absolutely in touch with the management as far as justice to the men is concerned. Object lessons are necessary in order to convince workmen of the desirability of changes, and it requires great ingenuity in preparing the right kind of object lessons. Each foreman should keep a small diary in which to jot down the principal events of the day. Such a diary may be of great value in case of a lawsuit. How to make the foreman keep the diary written up is another story. In order to get the most work out of a man for his money it is necessary to offer him a stronger incentive to do his best than the mere fear of discharge for incompetency. Cultivate the habit of instinctively thinking of and looking at work in terms not of quantity and time, but of time and dollars. An economic rule in choosing the drilling equipment and tools is to use the minimum diameter of hole in which the drill will freely work when the holes can be sprung, and as large as can be conveniently drilled when the holes cannot be sprung, except where the rock must be broken out in blocks with a mini- mum of waste. The economic result of springing holes lies in the fact that the holes can be placed much further apart, of a smaller diameter and a low and cheap grade of powder used. In tunneling through soft rock the objection to springing is that it produces fumes from the dynamite, which otherwise would not be used. To prevent this a good way is to spray the air with water after each shot if the water is available. SUGGESTIONS FOR ROCK DRILLING AND BLASTING 305 Under normal conditions water-washout jets will increase the output from 30 to 100%. Plot the location of all drill holes on cross-section paper and write thereon the depth of each hole and the powder charge in it. In drilling open-cut work it is wise to pitch the holes down away from the face. The explosion will then throw the rock away from the face and tend to avoid throwing loose rock over the unblasted portion. Quarry bars are very economical for drilling in open cuts and for plug drilling. Where long 1:ransmission pipes are usedj air is more econom- ical than steam. A steam line can be lagged 600' or 700' with economy. Air hose lasts longer than steam hose. Poor coal supply causes serious delay and loss of money. Cheap blacksmith's coal containing much sulphur is an expensive luxury, the reason being that some of the carbon will be burned out of the drill steel, thus reducing its effective hard- ness. Locate a forge away from sunshine or you are apt to burn the steel without knowing it. A white sparking heat usually means a spoiled tool. Keep parts of all machines together in storage, so that they can be found easily. If a 500-volt current is used to explode caps there will be many misfires. In blasting, use a 3-wire connection with a 3-wire machine, thus developing its full power. Where ij" sticks of dynamite are used, the drill hole should be i]^'' at the bottom. In dynamite water has a greater affinity for the guhr than nitroglycerin has, therefore in wet holes the nitroglycerin will slowly leave the cartridge -if it be not reasonably water-proof. Not so, however, with nitrogelatin. One of the most satisfactory rules in blasting is to avoid so ioading the holes as to throw much rock into the air. If a dense 306 ROCK DRILLING brown smoke with pieces of rock be thrown high in the air with each blast, the holes are too heavily loaded or the bulk of the charge is not low enough in the hole. Do not mistake activity for work. There should be the same sizes of tools for men competing, for example: A man who is paid for his performance on the 3J" drill should not be obliged to compete with another man paid on the same basis who is running a 3^'' drill When drilling in sandstone the drill-bit should be tapered somewhat and then flattened instead of drawn to a cutting edge. If a chisel-bit is used in drilling sandstone, the bit will wear very sharp, and will frequently become fissured. In forging rock-drill bits, those for medium hard rock should have sharp chisel-bits. As the hardness of the rock increases, the angle of the bit may be made more blunt, and the cutting edge shaped from a straight line to a curve, to prevent the corners being chipped off. An unsymmetrical bit, in which the blades do not all strike exactly alike, is preferable to the symmetrical kind, especially in hard rocks, resulting in less sticking. When the drill bit has become stuck run a powerful water jet through a half-inch pipe down to the bottom of the hole and work up and down. This is very effective in loosening up the bit, and will also enable a new bit to descend promptly to the bottom of the hole. If the bit is inclined to stick, churn up and down in the hole with a thin strip of hickory while drill is working, A handful of pieces of cast iron the size of hazel-nuts dropped into the hole, especially if the material varies much in hardness, will often prevent the bit from sticking. At a 45-ton blast in Manila the fumes killed several men. Ammonia should be inhaled where men are overcome by dynamite fumes. Blowing unexploded dynamite out of a hole with a steam jet — Don't! Use air instead. Never use a nail-puller to open a box of dynamite. Dynamite in a wooden box containing no metallic nails can SUGGESTIONS FOR ROCK DRILLING AND BLASTING 307 be burned up without exploding, but any nail or metal is likely to so conduct the heat as to explode the dynamite. If a cap is pointed at a stick of dynamite an inch away it will explode, if pointed to one side it will not explode. In springing for black-powder work, it is important not to load the hole until after the rock has cooled off, as the springing charge develops considerable heat. When fuse is used in cold weather it becomes hard and stiff, very often cracking and causing a misfire. Fuse should be thawed before using. Dynamite, when frozen, can be exploded by extra strong caps. Caps of different makes should never be used in the same charge. There should be no air cushions in the blast hole. To accom- pHsh this slit the cartridges with a knife lengthwise on two sides, being sure not to do this to a frozen or partly frozen stick, and place it well home with a wooden rammer. When mucking or drilling takes place and badly shatters or pulverizes the rock and the holes are close together, short pieces of drain tile can be erected over each hole to prevent small pieces of rock from falling into the holes until after the hole has been charged. These can be used repeatedly. For blasting out old piles and stumps average 30-40% dyna- mite is very effective. Four pounds of dynamite exploded 5' beneath the surface will break ice 2' thick to a distance of 30 or 40' around the shot. Instead of digging holes in which to plant trees, it is cheaper to churn a drill hole in the ground and charge with about one-half stick of 40% dynamite. The usual size of a case of dynamite is f of a cubic foot, therefore an old powder box is often more convenient for measuring coal than a bushel basket. For gaskets on pumps, the thinner the better. Upon laying up rock drills, hoists, etc, cover the bright surface with a mixture of paraffin and vaselin heated and applied with a brush. The mixture is readily rubbed off. 308 ROCK DRILLING Look out for air in water pipe at top of a grade. Provide a blow-off cock. In cold weather at night drain all water and oil from cylinders and lubricators of engines and pumps. The common lard oils are full of acid and will cut machinery. Cylinders of engines and. steam drills are frequently cracked in cold weather by suddenly letting in steam. To avoid this open drip cocks and cocks on steam chest and blow in steam for a few minutes to warm up the cylinder before starting the machine. A broken cylinder may delay work for a day. Hints for Estimators. Look out for misleading ''costs." The achievement of high wages for the workman and low labor cost for the owner is what can be obtained by proper economizing methods, accurate costkeeping, and timekeeping. Do not let precedent govern unless it is wise precedent, and see that when it does govern, the preceding conditions are repre- sentative of the present ones. A plant should be designed to do the work in say 20% less than the contract limit, making allowance for bad weather, delays in delivery and installation and delays due to breakdowns. In 22 days 86 channeler bits were used to channel 3779 sq.ft. in shale containing frequent ''nigger heads." This is at the rate of 43.94 sq.ft. per bit. Test pits in shale are uncertain and will generally show more earth and less rock than they should. A letter from a contractor in Engineering News^ October 23, 1902, p. 337, says the contractor, by making borings costing about $100, found earth where everyone expected rock, bid accord- ingly, and made $30,000. In bank blasting with black powder the general rule is, one pound of black powder will break 2-3 yds. of gravel. In figuring on rock bear in mind that a contractor will have to take off more rock than is paid for unless he is going to a great deal of expensive "sand-papering," and therefore his measurement when he gets to the edges of his excavation or to the bottom of it will usually be more than the amount of the engineer's monthly estimate. SUGGESTIONS FOR ROCK DRILLING AND BLASTING 309 Channeling is advantageous for quarrying large dimension stone except granite. Broach channeling is cheaper for granite. The weight per cubic foot (zinc ore) is dependent upon the percentage of mineral as well as upon the percentage of powder used in breaking the ore. In one experience the range in weight of dirt which has very nearly the same mineral content may be between 92 and 108 lbs. per cubic foot; in this case the variation was due entirely to a change from 30 to 40% dynamite. It is often cheaper to use a high grade of dynamite rather than to increase the diameter of the hole so as to secure a big charge of low-grade dynamite. Acknowledgment should be made of the excellent work in gathering the data contained in this volume by Messrs. W. T. Ball, A. C. Haskell. Chas. Houston and H. C. Lyons, and the marked courtesy rendered us by all the contractors to whom we applied for information. INDEX Accidents from dynamite, lo Acetylene lights at Detroit River, 87 Ahnapee Harbor, Wisconsin, 284 Air compressor, cost of, 53 Air, cubic feet after compression, 56 Air drills, .32 Air, efficiency of, 55 Air jets, 23, 46 Air lift, 77 Air pressure, 22 Air required, 54 Air washout, 102, 107 Altitude affecting air, 54 Amherstburg, Ontario, 75 Amount of explosive, 12 Andover, N J., D. L. & W. cut-off, 100 Aqueduct for New York water supply, 143 Atlantic Coast Contracting Co., East River, 293 Atlas powder, 3 B Bailing, 24 Bailing device, 82, 108, 118 Bit, Brunton, 44 bull, 46 chisel, 49 cross, 41, 46 removal from machine on drill boat, 189 round edge, 45 Simmons, 44 size of, 40, 41 spiral, 47 square- cross, 46 sticking of, 32, 306, 321 X, 44 Bit, Y, 45 Z, 47 Bits, 39 Andover, N. J., 102, 117 changing, 38 cost of sharpening, 50 kind used at Detroit River, 8r kind used at Vail, N. J., 107 shape of, 41, 127, 306 sharpening, 32, 44, 46, 47, 48 sharpening on Buffalo boat, No. 5^ 252 sharpening on '^Destroyer," 191 six-wing rosette, 46 tempering, 48, 50 time to change, 63 used at Columbia, N. J., 117 Black Rock harbor and channel, 278 Blacksmith, 50 Blacksmith coal, 51 Black Tom Reef, New York, 300 Blakeslee & Sons, Catskill Aqueduct, 143 Blasting, cost of {see Cost of Drilling). experience table of cost, 71 Blasting in tunnel, 102 Blasting machine, 15 Blasting on a drill boat, 212 Blasting, operation of, i Blyth, England, operations, 180 Boat, drill {see Drill Boat). Boiler horse-power, 55 Boilers used at Detroit River, 82 Boulders at Buffalo, 278 Brake horse-power, 56 Breakwater at Duluth-Superior Harbor, '^33 Breasting cables, Oak Point, 295 Breasting chains, 286 311 312 INDEX Breccia in Cripple Creek district, 155 Brownell Improvement Co., Thornton, 111., 125 Brunton bit, 44 Buffalo Boat, No. ±, 269 No. :j, 266 No. 4, 260 No, 5, 244 Buffalo Dredging Co., Buffalo, N. Y., 244, 278 Buffalo, N. Y., Black Rock Harbor and channel, 278 Bull bit, 46 Cable cars at Detroit River, 90 Cables as breasting lines, 287 Cableways at Detroit, 79 Canal from Sault Ste. Marie to Lake Huron, 159 Carbonite, 3 Cars, cost of, 125 Catskill Aqueduct, 143 Chadcayne Tunnel, 143 Chains as breasting lines, 287 Chambering, 14 Changing bits, ;^S Channeling, 309 Charging drill holes on "Earthquake," 225 Charging tube, 13 Charging tube used on Sullivan drill boats, 212 Chipeta Adit at Ouray, Colo., 152 Chisel bit, 49 Chuck, double-bolted U, 175, 235 Chucks, 38 Cienfuegos Harbor, Cuba, 291 Clay at Buffalo, 278 Coal, 51 Coal bunker of steel, 246 Coal consumption, 55 at Andover, 105 at Black Tom Reef, 301 at Buffalo, 280 at Columbia, N. J., 120 at Duluth, Minn., 138 at Galops Rapids, 288 Coal consumption, at Kennebec River, 298 at Livingstone Improvement, 86 at Oswego, 184 at St. Mary's River, 164, 170 at St. Mary's River, Sec. 4, 283 at Thornton, 111., 129 at Vail, N. ]., in on Buffalo Boat, No. 2, 268 on Buffalo Boat, No. i, 274 on Buffalo Boat, No. 4, 265 on Buffalo Boat, No. 5, 247, 252 on "Destroyer," 191 on "Dynamiter," 211 on "Earthquake," 224 on Edwards Bros.' boat, 175 on "Exploder," 202 on "Hurricane," 237 Coal, cost at Detroit River, 192 cost at Ouray, Colo., 154 cost at Thornton, 111., 129 cost of, 55 cost on Buffalo Boat, No. 5, 252 cost on "Exploder," 202 heating value, 55 loading at Detroit River cofferdam, 86 loading on a drill boat, 191, 252, 274 Cofferdam work, 75 Collar, Sergeant rotating, 79 Columbia, N. ]., D. L. & W. cut-off, Compressor plant at Detroit River, 84 Contract No. 2 5, New York water . supply, 143 Contract price, at Buffalo, 278 Buffalo Boat, No. i, 274 Buffalo Boat, No, 5, 252 cofferdam work, Detroit River, 84 Galops Rapids, 285 lames River, 290 Oswego, 182 Contract prices, Detroit River, 201, 224, 237 drill boat "Destroyer," 191 St. Mary's River, 282 Copper mines, 41 Coral at Cienfuegos, 291 Cost, see article in question. INDEX 313 Cost, checking up, 65 comparison between Lobnitz rock- breaker, drop drill barge, and sub- marine drills, 180, 181 Cost curves, directions for using, 64 Cost of air compressor, 53 Cost of blasting. {Sue also Cost of Drilling.) Cost of drilling, 52, 58, 67 Ahnapee Harbor, 285 Andover, N. J., 106 Black Tom Reef, 301 Blyth, England, 180 Buffalo Boat, No. 1, 276 Buffalo Boat, No, 2, 268 Buffalo Boat, No. 4, 265 Buffalo Boat, No. 5, 259 Buffalo, N. Y. 281 Catskill Aqueduct, 148 Cienfuegos Harbor, 292 Columbia, N. J., 123 "Destroyer," 197 Duluth, Minn., 141 "Dynamiter,'' 215 "Earthquake," 230 Edwards Bros.' drill boat, 177 "Exploder," 20^ Galops Rapids, 288 "Hurricane," 239 James River, 290 Kennebec River, 298 Livingstone Improvement, 93 Oak Point, 296 Oswego, 183 Ouray, Colo., 154 Portland Gold Mining Co., 156 St. Mary's River, 167 St. Mary's River, Sec. No. 4, 283 Thornton, 111., 132 Vail, N. J., 114 Costofdriving tunnel at Ouray, Colo., 154 Cost of explosives, 71 Cost of operating drill boat, percentages, 289 Cost of removing rock. {See Cost of Drilling.) Cost of sharpening bits, 50. {Also see Bits.) Cost of steam plant, 52 Cost of water j«ts, 31 Crane for handling bits, 248 Crews at drills. {See Cost of DriUing.) Cross bit, 41, 46 Croton Tunnel, 143 Crusher plant at Duluth, Minn., 132 Crushers, 125 Crushing plant at Thornton, N. J., 127 Cushioning effect, 14 Cutting speed, 40, 49, 62 Cylinder o^ drill, 36 D Dady, contractor at Cienfuegos, Harbor, 291 Dake engines for moving drills, 245 Dams at Detroit River, 75 Danger from dynamite, 10 Depreciation on plant at West Neebish Channel, 84 Depth of hole, 16, 38 Derrick boat, 77 Derrick, cost of, 2S2 "Destroyer," drill boat, 187 Detonating compounds, 2 Detonation, definition of, 2 facility of, 7 Detroit River, Buffalo Boat, No. i, 269 Buffalo Boat, No. 2, 266 Buffalo Boat, No. 4, 260 Buffalo Boat, No. 5, 244 Detroit River Channel, 220 Detroit River Improvement, 75 Detroit River, Livingstone Improve- ment, 184 Diameter of holes, 40 Direction of the hole, 51 D. L. & W. cut-off, 99 Dolly bar, 21 Dolomite rock at Columbia, N. J., 115 Dredge at Cienfuegos Harbor, 291 Dredge, cost of, 282 elevator type, 180 "Gladiator," 185 "Hercules," 185 "Old Glory," 185 314 INDEX Dredging, cost at Ahnapee Harbor, 285 cost at C)ak Point, 296 cost at Oswego, 184 Drill barge at Blyth, 180 Drill boat, Buffalo, No. i, 269 Buffalo, No. 2, 266 Buffalo, No. 4, 260 Buffalo, No. 5, 24^ Cienfuegos Harbor, 291 cost, 282 "Destroyer," 187 "Dynamiter," 209 "Earthquake," 220 Edwards Bros.', 171 ** Exploder," 199 for use in tide water, 295 Galops Rapids, 286 "Hurricane," 231 James River, 290 Oak Point, 295 Oswego, 182 St. Mary's River, 160 St. Mar}''s River, Sec. 4, 282 Sanford Ross type, 297 Drill cylinder, 36 Drill float, cost, 30 r Drill mounting in tunnel, 150 Drill mountings, 38 on Catskill Aqueduct, 144 Drill piston, 36 Drill repairs, at Columbia, N. J., 121 at Thornton, 111., 129 on "Destroyer," 192 Drill steel, 50 Drill stroke, 36 Drill, weight of, 38 Drilling, cost by air, 61 cost by steam, 60 cost of, 52, 59 experience table of cost, 67 through wells on boat, 286 Drills, air, 32 hammer type, 40 kind at Detroit, 79 large vs. small, 154 number of, 35 number sharpened by machine, 151 on boat moved by hydraulic, 260 Drills, on boat moved by stearn, 245^ '249 protecting in winter, 307 setting up, 22, 39 steam, 32 time to set-up, 63 tripod, on a scow, 284 Dualin, 3 Duluth Crushed Stone Co., Duluth,. Minn., 132 Dynamite, amount per hole at Thorn- ton, 111., 125 cost of, 283. {See Cost of drilling.) cost of, at Ouray, 154 danger from, 10 grade of, 4 per blast at Catskill Aqueduct, 146 size of cartridges, 4 specific gravity, 10 weight of, 10 weight of cartridges, 4 "Dynamiter," drill boat, 209 "Earthquake," drill boat, 220 Eastern Dredging Co., Kennebec River, 297 East River, Oak Point, 293 Economic Grade of powder, 6 Edwards Bros.' Drill Boat, St. Mary's River, 171 Ejector pipes, Black Tom Reef, 299 Electric firing, 15 Electric power, 34 Empire Engineering Corporation, Buf- falo, N. Y., 278 Estimating costs, 58 "Exploder," drill boat, 199 Explosion, definition of, i flame from, 9 Explosives, amount of, 12 consumed in tunneling, 158 experience table of cost, 71 frozen, 2, 8 power of, 5 Explosives proper, i Explosives, slow-acting, 6 INDEX 315 Pacility of detonation, 7 Feed, 59 JFeet, per minute in jasper ^nd quartzite, Ferro-titanium, 50 Firing, 15 simultaneous, 15 Flame from explosion, 9 Flickwir, D. M., work at B, L. & W,. cut-off, ICO Flint in Kennebec River, 297 Flint rock at Buffalo, 278 Floatable platform for drilling, 299 Porcite, 4 Freezing, 54 of nitroglycerin, 8 Frozen explosives, 2 , 8 Frozen work, 307, 30& Fuel, 32 Fuller and Dollie sharpening, 48 F'umes, 9 from dynamite, 304 Galops Rapids, St. Lawrence River, 285 Ga$ plant for lights on Buffalo Boat, No. 5, 248 Oelignite, 4 ■Giant powder, 3 Gilbert Bros^ Engineering Co., Galops Rapids, 285 Gneiss at Oak Point, 293 Granite at Andover, 103 Granite at Black Rom Reef, 302 Granite at Duluth, Minn,, 133. Granite at Oak Point, 293 Granite on Catskill Aqueduct,- 145 Grade of dynamite, 4 Grade of powder, 15 Graywacke sandstone at Oswego, 182 Great Lakes Dredge Dock Co., 160 Gunpowder, composition of, i H Flammer type drills, 40 Hand sharpening, 46 Flardness of rock, 20 Hart, Jas. A-., & Co., on D. L, & W. cut-off, 115 Hay Lake and Neebish Channel, St. Mary's River, 282 Heat, 32 Heating exhaust water, 222 Hercules, '3 Kingston, Rogers & O'Brien, Oswego Harbor, 182 Hings in drilling and blasting, 303 Hole, direction of, 5 1 Holes, arrangement in a quarry, 125 arrangement in a tunnel, ico, 144, 145 blasting on "Dynamiter," 213 depth of, 16, ,38 depths on various work^ {See Holes, spacing.) direction in open-cut work, 305 Holes per blast, Buffalo Boat, No. i, 2 73 Buffalo, Boat No. 5, 250 Catskill Aqueduct, 147 Columbia, N. J., 118 Duluth, Minn., 138 "Dynamiter," 210 "Earthquake," 223 "Exploder," 20 r Galops Rapids, 287 "Hurricane," 236 Port Colborne, 182 Thornton, 111., 127 Vail, N., J., 109 Holes, size of, 14, 39, 40 spacing of, 14, 15 spacing at Ahnapee Harbor, 285 spacing at Andover, 103 spacing at Black Tom Reef, 300 spacing at Buffalo, 278 spacing on Buffalo, Boat No. i, 273, 277 spacing on Buffalo Boat, No. 4, 264 spacing on Buffalo Boat, No. 5, 249 spacing at Cienfuegos Harbor, 291 spacing at Columbia, N. J., 118 spacing on "Destroyer," 190, 197 spacing at Duluth, Minn., 137 spacing on "Dynamiter," 210, 215 spacing on "Earthquake," 223 316 INDEX Holes, spacing on Edwards Bros.' drill boat, 176 spacing on "Exploder," 201, 2CJ5 spacing on "Hurricane," 235 spacing at James River, 290 spacing onKenhebecRiver, 297' spacing at Port Colborne, 182 spacing at St. Mary's River, 163 spacing on St. Mary's River, Sec. 4, 283 spacing at Thornton, 111., 127 spacing at Vail, N. J., 109 springing, 12, 13 tamping, 7 wet, 12, 15 Horse-power necessary, 55 Horse-power required f6r compression, 56 Horsley powder, 4 "Hurricane," drill boat, 231 I Improvement of Oswego Harbor, New York, 182 Improving Ahnapec Harbor, Wisconsin, 284 Improving Black Rock Harbor and Channel, Buffalo, N. Y., 278 Improving James River, Va., 290 Iron mines, 4 J James River, Va., 290 Jasper at Towar, Minn., 151 Jets, 23, 39, 62 air, 46, 63 on drill boat at West Neebish Chan- nel, 166 water, 21, 23, 31, 46 Judson Giant Powder, 4 Kennebec River, Me., 297 Large vs. small drills, 154 Lighting of work at iright, 87 Limestone, Ahnapee Harbor, 285 Buffalo Boat, No. 5, 250 Buffalo, N. Y., 278 Columbia, N. J., 115 Detroit River, 190, 201, 223, 235 Galops Rapids, 285 Livingstone Improvement, D etroit River, 81 Port Colborne, iSi Thornton, 111., 125 Livingstone Improvement, Buffalo Boat, No., I, 269 •' Buffalo Boat, No. 2. 266 Buffalo Boat, No. 4, 260 Buffalo Boat, No. 5, 244 of Detroit River, 75, 184, 220 Loading holes, 305 Lobwitz rock breaker, iSo Locher, C. H., traction drill, 87 Locomotive, crane, 133, 135 Lovejoy's Narrows, Kennebec River^ Me., 297 M Measurement of rock, 308 Mica schist at Oak Point, 293 Mounting of drills, 38. (See also Drills.) Mucking, 53 amount of, 53 at Ouray, Colo., 153 cost of, 54 in tunnel, 156 Mud capping, 3 Mudding, 42 Mud pipe, on Buffalo Boat, No. i, 272. {Also see Sand pipe.) on Buffalo Boat, No. 5, 253. (Also- see Sand pipe.) wear of, 252 N Neebish Channel, St. Mary's River, 282 Neebish Island, Edwards Brothers, 171 New York, New Haven & Hartford R. R. Improvements, Oak Point, East River, 293 New York AVater Supply, Catskill Aqueduct, 143 INDEX 317 Nitroglycerine, freezing of, 2, 8 Non-freezing powders, 9 Number of drills, 35 O Oak Point, New York City, 293 Observations on Livingstone Improve- ment of the Detroit River, 184 Oil consumption, Andover, 105 Buffalo Boat, No. i, 274 Buffalo Boat, No. -i, 268 Buffalo Boat, No. 4, 265. Buffalo Boat, No. 5, 252 Columbia, N. J., 120 "Destroyer," 191 Duluth, Minn., 138 "Dynamiter," 211 "Earthquake," 224 Edwards Bros.' Boat, 175 "Exploder," 202 Galops Rapids, 288 "Hurricane," 238 Livingstone Improvement, 86 St. Mary's River, 164 vSt. Mary's River, Sec. 4, 283 Thornton, 111., 129 Vail, N., J. Ill Oliver Iron Mining Co., T^war, Minn., Operation of Blasting, i Operations at Blyth, England, 180 Oswego Harbor, New York, 182 Ouray, Colo., mine tunnel, 152 P Piles, blowing, 307 Pioneer Mine, 152 Pipe connections, 34, '^$ Piston of drill, 36 Platform method of drilling, 299' Plug holes at Duluth, 134, 136- Pluto powder, 223 Port Colborne Harbor Works, Welland Canal, Canada, 181 Pordand Gold Mining Co., 154 Pound degrees from water at 35^, 5^- Powder, economic grade of i 6 Powder, grade of, 15' Powder, non-freezing; 9 Power, cost of, 54 Power of explosives, 5 Power sharpener, 46 Pressure, 34, 37 Pressure of air, 55 Pressure of air and steam, 2 2 Price of crushed stone, 129, 138 Primer strength, S Pumping, 22, 39 Pumping at Detroit River, 75 Pump on boat at West Neebish Channel, 166 Pumps, centrifugal at Detroit, 77 Pumps on Edwards Brothers*BoL\t,i73 Q Quarry bar, 38 Quarry, Duluth, Minn., 132 Thornton, 111., 125 Quartz, Oak Point, 293 Quartzite, Ouray, Colo., 152 To war, Minn., 151 R Rapidity of action of explosives, 6 Ratio of scov/ to place measurement, 2S5 Reaming edge, 42 Record of cost at Buffalo, N. Y., 280 Record for two weeks, Buffalo Boat» No. J., 276 Record for one month, Buffalo Boat,, No; 2, 269 Record for two months, Buffalo Boat, No. 4, 266 Record for two months, Buffalo Boat, No. 5, 260 Record for one week, on "Dynamiter," 214 Record for four months on "Earth- quake," 231 Record for one week on "Exploder," 203 Record for four months of "Hurricane," 240 Record of cost on St. Mary's River, Sec. 4, 284 Reiter, Curtis & Hill, contractors at Vail, N. J., 107 Rendrock, 3 318 INDEX Repairs to drills at Columbia, 121 Repairs to plant, Black Tom Reef, 301 Repairs at Thornton, 111., 129 Repairs, West Neebish contract, 86 Report card used at Livingstone Im- provement, 97 Risk from dynamite, 10 Rock, 21, 32, 42, 49 Rock breaker, Lobnitz, 180 Rock, hardness of, 20 Rock loosened, 16 Roseville tunnel, 100 Round-edge bit, 45 Rubble plant at Duluth, Minn., 13.3 St. Lawrence River, Galops Rapids, 285 St. Mary's River, 159 Section 4, 282 Edwards Bros.' Drill Boat, i;x Michigan, Hay T .ake & Neebish Channel, 282 Sand at Buffalo, 278 Sand pipe, 225. (See also Mud pipe.) Sand pipe wear, 231 Sandstone at Blyth, England, 180 Sandstone, drilling in, 306 Sandstone at Oswego, 182 Sandstone at St. Mary's River, 163, 174 Sanford, contractor on James River, 290 Saunders' platform method, 299 Savoy mine, 152 Scow, cost of, 282 Scow at Detroit River, 77 Scow with tripod drills, 284 Sergeant rotating collar^ 79 Serpents, 77 Setting up drill, 22, 39 Setting up drill on a column, 150 "Set-hammer" sharpening,. 47 Shaft bar, 38 "Shakedown," 13 Shale rock, 21 Shape of bits, 41 Sharpening bits, 32, 44» 47' 48 Ship channel of the St, Lawrence, Galops Rapids, 285 Simmons bit, 44 Simultaneous firing, 15 Six-wing rosette bit, 46 Size of bits, 41 Size of cartridges, 4, 15 Size of hole, 14, 3Q, 40. (See also Holes, spacing.) Slate in Kennebec River, 297 Slate-at Vail, N. J., 113 Slowest acting explosives, 6 Sludge, 21, 22 Smith, McCormick & Co., D. L. & W. cut-off, 115 Soudan Mine at Towar, Minn., 151 Spacing holes, 13, 15 Specific gravity of dynamite,' 10 Speed of cutting, 40 Spiral bit, 47 Springing holes, 12, 13 Square cross-bit, 46 Standard Contracting Co., St. Mary's River, 282 Steam drills, 32 Steam hammer on Buffalo Boat, No. 5, 247 Steam, loss of energy, 57 Steam plant, cost of, 52 Steam power, 35 Steam pressure, 22 Steam shovel at Detroit, 79 Steam shovels, 125 Steam volume at given pressure, 56 Sticking of bit, 2 1 Stonite, 3 Strength of primers, 8 Stroke of drill, 36 Stumps, blowing, 307 Submarine drilUng by platform method, S99 Submarine rock excavation, Welland Canal, Canada, i8r Suspended track at Andover, 100 Tamping, 13 Tamping holes, 7 Tappet holes, 154 Telescopic tube for drilling, 299 Temperature at given pressure, 56 INDEX 319 Tempering, 48, 50 Test borings, 308 Thawing out drills on drill boat, 222 Thornton, 111,, quarry, 125 Time study of drilling, 58 Time study, Andover, N. J., 106 Buffalo, Boat No. 5, 261, 262, 263 Catskill Aqueduct, 149 Columbia, N. J., 124 "Destroyer," iq4, 195 Duluth, Minn., 142 "Dynamiter," 217, 218, 219 "Earthquake," 232, 233, 234 Edwards Bros.' Drill Boat, 178 "Exploder," 206, 207, 208 "Hiurricane," 241, 242, 243 Livingstone Improvement, D etroit River, 94, 96 St. Mary's River, 171 Thornton, 111., 132 Vail, N, J., 115 Tipple, 135 Towar, Minn., Soudan Mine, 151 Traction drill, 87 Trees, holes for planting, 307 Tripod, 38 Tripod legs, 2 1 Tug, cost of, 282 Tunnel, driving in the Cripple Creek district, 154 Tunnel work, Castkill Aqueduct, 143 Ouray, Colo., 152 U U-chucks, 79 Vail, N. J., D. L. & W. cut-off, 107 Value of plant, Andover, N. J., 105 Black Tom Reef, 301 Blyth, England, 180 Buft'alo Boat, No. i, 275 Buffalo Boat, No. 2, 268 Buffalo Boat, No. 4, 265 Buffalo Boat, No. 5, 252 Buffalo, N. v., 281 Catskill A({ueduct, 147 Cienfuegos Harbor, 292 Value of plant, Columbia, N. J., 120 "Destroyer," 193 Detroit River cofferdam, 86 Duluth, 138 "Dynamiter," 213 "Earthquake," 224 Edwards Bros.' Boat, 176 "Exploder," 202 "Hurricane," 238 Kennebec River, 298 Oswego Harbor, 183 St. Mary's River, Sec. 4, 282 Thornton, 111., 129 Vail, N. J., Ill West Neebish Channel, 165 Ventilation at Ouray, Colo., 153 Vigorite, 4 Vulcanite, 4 W Wages, Oak Point, 296 Ouray, Colo., 153 standard rates for subaqueous work, 159 standard rates on land, 66 Water in hole, 15 Water jet, 21, 23, 46, 305 cost of, 31 "Destroyer," 189 Edwards Bros.' Boat, 175 Waterproof cartridge, 12 Water tank, 48 Weight of cartridges, 4 Weight of drill, 38 Weight of drill, steel, 41 Weight of dynamite, 10 Welland Canal, Canada, iSi West Neebish Channel, St. Mary's River, 159 Wet-hole work, 12, 54, 305 X X-bit, 44 Y Y-bit, 45 Z Z-bit, 47 Zenith Mine, 152 ^- - ■-'z^rmr/r^C'.