CORNELL UNIVERSITY LIBRARY Supt, of Documents CORNELL UNIVERSITY LIBRARY 3 1924 092 701 766 CLIN UBRABY- CIRCULATION DATE DUE PRINTEDINU.S.A. Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31 924092701 766 A\ ^• ^^ Ordnance Department Document No. 2034 RAILWAY ARTILLERY A REPORT ON THE CHARACTERISTICS, SCOPE OF UTILITY, ETC. OF RAILWAY ARTILLERY IN TWO VOLUME! VOLUME II WASHINGTON GOVERNMENT PRINTING OFFICE 1922 l^WIVl^liM'i W V 1 ^ti^ii' War Department, Office of the Chief of Ordnance, June IS, Tliis work on Railway Artillery is a Report on the Characteristics, Scope of Utility, etc., of Railway Artillery, prepared by H. W. Miller, lieutenant colonel of Ordnance Reserve Corps. This report is ap- proved for publication for confidential use only. C. C. Williams, Major General, United States Army, Chief of Ordnance. PREFACE. To repeat a portion of the preface of Volume I, this volume is a part of a report submitted by the Heavy Artillery Section, Engineer- ing Division, Office of the Chief Ordnance Officer, A. E. F., France. The original report was submitted in April, 1918, and was so framed as to answer, as well as time for the investigation permitted, ques- tions that were troubling the designers and builders of this type of artillery in America. The second and more complete report was completed in March, 1919. In this report an attempt w-as made to record as many as possible of the lessons learned during the war and to give working descriptions of all of the artillery of this type owned or used by our allies, the Entente, and by ourselves. When it was decided to publish the report to serve both as a refer- ence and text our allies were consulted with reference to the publish- ing of the descriptions of their artillery. Each replied that they had no objection to its being published and used confidentially, but they preferred not to have it published for general and public distribu- tion. This second volume is hence issued for confidential use only. CONTENTS. (This elaborate table of contents is given in lieu of an index. Since the entire volume is devoted to the detailed description of the various mechanisms of a definite group of guns and mounts it is believed that such a table will more effectively serve the purposes of users of the book than an index of the conven- tional type. In the text reference is sometimes mnde to materiel by number. These numbers are those given in left column of table below.) FRENCH ARTILLERY. 1. 120-niillimeter gun on Schneider-Canet-Peigne railway mount 1— "i History 1-2 Recoil mechanism >> Traversing mechanism 4 Trucks 5 2. l."i.5-millimeter howitzer on Schneider-Canet-Peigne railway mount — 6-8 History 6 Railway car body T System of anchorage 8 3. 155-millimeter gun on Improvised mount 9-H) General description 9 System of anchorage * 10 4. 164.7-millimeter gun on improvised mount, H-13 History and general description 11-12 System of anchorage 13 5. 194.4-millimeter howitzer, model 1875-76 on improvised mount 14-23 General description 15 Recoil mechanism " 25 Elevating mechanism 16-17 Traversing mechanism 18 Gun carriage 19 Railway car body 20 System of anchorage 21 Trucks 22 Ammunition supply system 23 6. 194.4-milllmeter howitzer, model 187.5-76, on carriage, model 1917 24-31 General description 24 Recoil mechanism 25 Elevating mechanism : 26 Traversing mechanism '. 27 Gun carriage 28 Railway car body i 29 System of anchorage 30 Difficulties involved in service 31 7. lfH.4-milllmeter howitzer, model 1875. 1876, 1878, on three axle mount- H2 8. 194.4-millimeter gun, model 1887, 1898, 1896, 1902, on improvised mount 33 9. 194.4-millimeter gun, model 1870, 1893 on improvised mount 34 (V) VI 10. 194.4-milliiiieter gun, model 1870, 1893 on three axle mount 35 11. 194.4-millimeter gun, model 1870, 1893 on double truck mount 36-44 General description 36 Recoil mechanism ■ 37 Elevating mechanism 38 Traversing mechanism 39 Gun carriage 40 Railway car body 41 System of anchorage 42 Ammunition supply system 43 Difficulties involved in service 44 32. 200-millimeter howitzer on special mount 4o-.54 History 45 Gun 46 Recoil mechanism 47 Elevating mechanism 48 Traversing mechanism 49 Gun carriage 50 System of anchorage 51 Trucks 52 Ammunition supply system 53 Merits 54 13. 240-millimeter howitzer, Model 1876, on improvised mount 55 14. 240-millimeter howitzer. Model 1876, on railway mount, Model 1917_ 56 15. 240-millimeter howitzer. Model 1876, on G. P. C. mount 57-64 History 57 Recoil mechanism , 58 Elevating mechanism ^ 59 Traversing mechanism 60 Gun carriage 61 Railway car body ! 62 System of anchorage . 63 Trucks 64 16. 24-millimeter gun. Model 1893, 189B, on St. Chamond mount 65-79 General description 65 Gun 66 Recoil mechanism 67 Elevating mechanism 68-69 Traversing mechanism 70 Gun carriage 71 Railway car body 72 System of anchorage 73-75 Trucks 76 Ammunition supply system 1 77 Maintenance 1 78 Difficulties involved in service 79 17. 240-millimeter gun. Model 1884, on mount without traverse 80 18. 240-millimeter gun. Model 1884, on mount with traverse 81 19. 340-millimeter gun. Model 1870, 1884, 1887 82-86 General description 82 Gun 83 Elevating mechanism 84 System of anchorage 85 Ammunition supply system 86 VII 20. 240-millimeter gun, Model 1903 87-97 General description 87 Gun 88 Recoil mechanism 89 Elevating mechanism 90 Traversing mechanism 91 Railway car body 92 System of anchorage 93 Trucks 94 Ammunition supply system 95 Difficulties in service 96 Merits 97 21. 274.4-millimeter howitzer, Model 1870, 1S81, and 1870M 98-106 General description 98 Gun 99 Recoil mechanism 100 Elevating mechanism 101 Traversing mechanism 102 Railway car body 103 System of anchorage 104 Trucks 105 Ammunition supply system 106 22. 274.4-millimeter gun. Model 1893, on improvised mount 107-117 General description 107 Gun 108 Recoil mechanism 109 Elevating mechanism 110 Traversing mechanism 111 Gun carriage 112 Railway car body -, 113 System of anchorage 114 Trucks 11.5 Ammunition supply system 116 Maintenance 117 23. 274.4-millimeter gun. Model 1893, 1896, on sliding type mount 118-128 General description US Gun _ _ 119 Recoil mechanism 120 Elevating mechanism 121 Traversing mechanism 122 Gun carriage and railway car body 123 System of anchorage 124-125 Trucks 126 Ammunition supply system 127 Maintenance 128 24. 274.4-millimeter gun, Model 1893, 1896, with recoil on mwunt 129-136 General description 129 Gun ^ 130 Recoil mechanism . 131 Elevating mechanism 132 Traversing mechanism I33 Gun carriage and railway car body 134 System of anchorage I35 Ammunition supply system 13g VIII ' 25. 285-iiiilliii.'eter gun, Model 1893, 1896 137 26. 293-miIIlmeter mortar. Model 1903 138-141 General description 138 Gun 139 Recoil mechanism 340 Ammunition supply system 141 27. 305-millimeter gun. Model 1893, 1896, on BatignoUes mount 142-l.'iH General description and history 142 Gun 143 Recoil mechanism 144 Elevating mechanism 145 Traversing mechanism 146 Gun carriage 147 Railway -ear body ' 148 System of anchorage 149 Ammunition supply system 150 Maintenance 151 Difficulties in service 152 Merits and demerits 153 28. 305 millimeter gun, Model 1893, 1896, on St. Chamond mount 154-158 General description n.j4 Elevating mechanism 15.") Traversing mechanism 156 System of anchorage 157 Demerits 158 29. 305-millimeter gun. Model 1893, 1896, on sliding type mount 159 30. 305-millimeter gun. Model 1906, 1910, on sliding type mount 160-161 General description 160 Trucks 161 31. 320-millimeter howitzer. Model 1870, 1884, 1893, on sliding type mount I 162-164 General description 162 Gun ! 163 Elevating mechanism 164 32. 320-miIUmeter howitzer, Model 1870, 1881, on sliding type mount__ 165 33. 320-millimeter howitzer. Model 1881, 1884, on sliding type mount___ 166-167 General description 166 Elevating mechanism ^ 167 34. 340-millimeter gun. Model 1893, on sliding type mount 168 35. 340-millimeter gun, Model 1912, on St. Chamond mount 169-183 General description 169 G^n 170 Recoil mechanism 171 Elevating mechanism 172 Traversing mechanism 173 Railway-car body 174 System of anchorage 175-179 Trucks • 180 Ammunition supply .^vstem 181 Maintenance 182 Difficulties in service 183 36. 340-millimeter gun. Model 1912. on sliding type mount 184 37. 370-millimeter howitzer on BatignoUes mount 185 38. 370-milllmeter howitzer. Model 187."). 1879, on sliding type mount— 186-187 IX 39. 4(X)-millimeter howitzer, on St. diamond iiionnt 188-199 General description , 188 Recoil inechiinisiii 189 Elevating mechanism 190 Traversing meclianism , 191 Gun carriage 192 Railway-car body 193 System of anchorage 194-196 Truclfs 197 Ammunition-supply system 198 Maintenance 199 40. 520-millimeter howitzer, on slidiug-type mount 200-210 . General description and history 200-201 Gun , 202 Recoil mechanism 203 Elevating mechanism 204 Traversing mechanism 20.j System of anchorage 206 Trucks 207 Ammunition-supply system 208 Merits 209 Demerits 210 BRITISH ARTILLERY. 41. 9.2-inch gun, Mark XIII on railway mount :;]1-221 General description 211 Gun 212 Recoil mechanism 213 Elevating mechanism 214 Traversing mechanism 215 Gun carriage 216 Railway-car body 217 System of anchorage 218 Truciis 219 Ammunition-supply system 220 Difficulties in service 221 42. 9.2-inch guns, JIarlis X and XIV on railway mount 222-223 43. 9.2-inch guns, Marks III to Vic 224-232 General description 224 Gun 22."i Recoil mechanism 22(! Elevating mechanism 227 Traversing mechanism 228 Gun carriage 229 Railway-car body 230 System of anchorage 231 Ammunition-supply syytem 2.S2 44. 12-inch howitzer, Marks I and II 233-241 General description 233 Gun 234 Recoil mechanism 23.") Elevating mechanism 236 Traversing mechanism 237 44. 12-inch howitzer, Marks I and II — Continued. Gun carriage 238 Railway-car body 239 System of anchorage 240 Ammunition-supply system 241 45. 12-inch howitzers, Marks III and V 242-250 General description 242 Gun 243 Recoil mechanism 244 Elevating mechanism 245 Traversing mechanism 246 Gun carriage 247 Railway-car body *248 System of anchorage 249 Ammunition-supply system 250 46. 12-inch gun, Mark IX 251-263 General description 251 Gun 252 Recoil mechanism 253-255 Elevating mechanism 256 Traversing mechanism 257 Gun carriage 258 Railway car body 259 System of anchorage 260 Trucks 261 Ammunition supply system 262-263 47. 12-inch gun ^ 264-275 General description 264 Gun 265 Recoil mechanism 266 Elevating mechanism 267 Traversing mechanism 268-270 Gun carriage 271 Railway car body , 272 System of anchorage 273 Trucks 274 Ammunition supply system! 275 48. 14-inch gun, Mark III 276-290 General description and history 276 Gun : 277 Recoil mechanism 278-279 Elevating mechanism 280 Traversing mechanism j. 281 Gun carriage 282 Railway car body . 283 System of anchorage 284 Trucks 285 Ammunition supply system 286 Maintenance 287 Difficulties involved in service 288 Merits 289 Demerits 290 XI ITALIAN ARTILLERY. 49. 381-millimeter gun, on sliding type mount 291-301 General description 291 Gun 292 Recoil mechanism 293 Elevating mechanism 294 Traversing mechanism 295 Gun carriage 296 Railway car body 297 System of anchorage 298 Trucks - 299 Ammunition supply system 300 Maintenance 301 AMERICAN ARTILLERY. 50. 14-inch gun, on railway mount, Model 1920 302-323 General description and history ^ 302-303 Gun I 304 Recoil mechanism 305-306 Elevating mechanism 307-309 Traversing mechanism 310-314 Gun carriage 315-316 Railway car body 319 System of anchorage , 320-321 Trucks 322 Ammunition supply system 323-326 Table of classified data 327 FRENCH ARTILLERY. 120-MILLIMETER GUN. 1. The history of the carriages on wliich these pieces are mounted is interesting. The first concrete results of interest to Frencli de- signers and experimenters in railway artillery seems to have been the ■work of General (then Colonel) Peigne, under whose direction a number of mounts of the stjde shown on Plates 1, 2, 4, and 5 were made up in 1888. They, were known specifically as Schneider-Canet- Peigne mounts. No record has been found with reference to their use by France in any wars prior to the recent war. A number of them were made by the Schneider Co., however, for- the Government of Denmark, for use in the defense of their coast. The mounts were exhibited at the Paris exposition in 1900 and the descriptive booklet from which Plate 1 is taken was made up at that time. 2. The desperate need of the armies on both sides of the line in the conflict just passed is apparent from the fact that both used practically any gun that would shoot and practically any carriage that would satisfactorily carry the gun. The writer found among the captured German artillery some bronze cannon of a very crude type mounted on wood carriages without any recoil mechanism. These same cannon had probably been used in the war of 1870. On the other hand, our own forces used the guns and carriages shown on Plate 4. These were photographed in the arsenal at Toul where they had been parked after we had finished using them in the sector north of Toul. No record has been seen with reference to the effec- tiveness of their service; this is probably the only actual warfare that these mounts have seen, however. On Plate 4 an improvised engine can be seen in front of the mount. This is a gas engine mounted on a four-wheeled truck and furnished the motive power for maneuvering the mounts on the front. 3. Recoil mechanism. — The one feature that impresses one as most unique and of greatest interest on this mount is the recoil mecha- nism. For a mechanism of the period of 1888 it embodies some admirable and ingenious features. The details are seen best on Plates 1 and 2. There are three distinct subdivisions to the mechanism. These are, first, two hydraulic cylinders, Plate 2, embodied in the top or gun carriage, to check the recoil of the gun and its carriage as they slide to the rear. The second- feature is the vertical hydraulic (r) 9 Si cylinder Y, lower figure, Plate 1, into which the vertical piston at- tached to the swinging carriage passes and by means of which the downward swing of the gun carriage is checked. The third is the pair of Belleville spring cylinders which operate in conjunction with the single hydraulic cylinder to check the downward swing of the carriage, and as soon as the recoil ceases they return the carriage to its normal position. There is nothing unusual about the first feature, but there is in the curious combination of the second and third. In Plate 1 ALL ROUND FIRE RY. MTS., EARLY FRENCH DESIGN, AND RAIL CLAMPS. SHOWING OUTRIGGERS lower figure, Plate 1, it will be seen that the vertical piston has on its end a head that fits snugly in cylinder Y and is perforated so that the glycerin may pass through it around the throttling rod as the piston moves downward. When the force of recoil is greatest the tendency of the liquid in the cylinder to force out either head operates in pushing out the floating gland T, the arms of which are attached to the two rods of the spring cylinders. The springs are thus further compressed until recoil ceases, when they pull in the rods, forcing the floating gland back into its place. This compels the vertical piston to rise and the carriage to return to its normal position. The net result is, of course, to keep a considerable pressure on the liquid at all times. It is interesting to note that the Belleville springs were so early put to service in railway artillery. 4. Traversing mechanism. — The traversing mechanism seems quite crude, though it is aocurate in its operation. The carriage is rotated into its approximated position through the use of two bars inserted in two sockets. When the gun is approximately laid in azimuth Plate 2 120-MM. EIFLE ON PEIGNB-CANBT CARRIAGE SHOWING PARALLEt RECOIL CYLINDERS. the clamp of what may be termed a fine adjustment mechanism is drawn and the carriage set accurately by means of a screw, Plate 5. 5. Trucks. — These mounts when photographed were on extra- narrow gauge trucks of only 60 centimeters. Plate 3 shows Colonel Peigne's original idea for operating the mounts on tracks of 1 meter and 1.45 meters gauge. By an ingenious method of sliding the wheels t/Utward on the truck axles the narrow, or 1-meter, gauge can readily be changed to standard or 1.45 meters. 452—22—2 155 HOWITZER. 6. The history of these mounts is identical with that of the pre- viously discussed mount. Apparently the design was made orig- inally to take either the 120-millimeter gun or the 155-millimeter Plate 3 rfkj ;%«>< ■'ar-^.»-"- , J METHOD OF ADJUSTING TRUCK WHEELS FOR DIFFERENT GAUGE TRACKS. howitzer, since either piece can be mounted on the carriage without any special provisions. 7. Gar body. — As mentioned in paragraph 5 these- mounts were equipped with 60-centimeter trucks. This fact rendered them of greatest service in consideration of their range. The car body is of the drop frame type, is made of steel throughout and is supported on two four-wheel trucks of very sturdy design. In the center and on both sides there is a hinged platform that travels in a vertical posi- tion, Plate 4. These platform extensions are necessary in operating the gun at wide angles to the truck, since all operation of the gun must be from the floor of the car. 8. System of camhorage. — An observation with reference to de- velopments in design during the war may be of interest here. The Schneider sliding type of carriage is thought of as new, whereas the principle of permitting the mount to recoil on the track was a development of our own Civil War and the use of sleepers to trans- mit the shock of recoil to the track was a feature of the mount under discussion if it was not actually developed with it. Two sleepers Plate 4 ^ -'v^'"-- ^ ^^ii|| ^^- - j^MpCj ^^Liit- „— nmn iv — "S^'' H 1 m LJBttfti ^^^^Hu^nH^^"-V'iS<' fj B&J^i . ^ II ■6 s OLD PEIGNE-CANBT MOUNT USED BY AMERICAN FORCES IN LATE WAR. are provided with each mount and are inserted between the low center section of the car and the rails. In addition there are two hinged outrigger arms on each side with screws through the ends, which are run down hard on iron-shod wood floats or pads about 18 inches square. These are, of course, to prevent overturning of the car when the gun is fired at wide angles to the track. This same principle of anchorage has been used on even the most elaborate of designs of this war. In some cases the principle has been somewhat camouflaged, it is true, but it is nevertheless the same. Coming back to the observation started above it seems to the writer that the credit for the most significant new development in anchorage de- signs of the war must be given to the Germans. The reference here is to the hinged central pivot'which served as a part of the travers- ing mechanism as well as a part of the anchorage of the 210, 240, and 280 millimeter, paragraphs 336-380, Volume 1. ri.ATE nA 150-MM. HOWITZERS. PLATFORMS IN FIRING POSITION. rr-ATE 51? *t. 155-MM. HOWITZER MOUNT. WORKING PLATFORMS IN TRAVELING POSITION 155 GUN. 9. This mount is a combination of seacoast gun with its coast carriage and an improvised railway car. The gun is 27 calibers in length and is mounted on a gun lift type of carriage, Plate 6. The car body is of plate steel, and appears to be the body and trucks of an extra-length standard railway car. There are no features of design that can be considered of value although some are interest- ing. It is simply one of the hurriedly improvised mountings for an existing seacoast gun and carriage, and after the supply of guns was exhausted was, of necessity, laid aside. 10. System of anchorage. — The system of anchorage embodies three separate features — a heavy timber pad directly beneath the gun, hinged outrigger arms, and rail clamps. Plates 6 and 7. It will be observed on Plate 6 that the timber pad directly under the gun carriage is let down onto the rails and the car body forced up slightly by means of the four screws passing through the floor of the car. The outrigger arms are attached to the ends of heavy wood beams passing entirely across the car, both above and below. The timber floats or pads are permanently attached to the screws on the ends of the arms and the whole is shown in traveling order on Plate 7. On Plate 6 two rail clamps can be seen near the out- rigger arms. Each rail clamp is attached to a screw passing through the car body in order that the car may be drawn down tight to the track. With this quite complete system of anchorage the gun can, of course, be operated through its entire traverse of 360 degrees. 164.7-MILLIMETER GUN. 11. All of the guns mounted on the carriage that comes under this heading are naval guns of 45 calibers length. They were made available early in the war when it was apparent that the German fleet would be comparatively inactive. The use of guns of this caliber of which there was no duplicate for land service brings up an interesting side issue. In 1918 the 155-millimeter G. P. F. guns were wearing out so rapidly under the excessive service that the manufacturing facilities in France were not sufficient to provide replacements, tube renewals, and additional guns for new troops. One of the solutions that was advanced was to rebore the 155-milli- meter guns to 164.7, shrink on an extra hoop at the breech, and in- crease the powder charge sufficiently to retain the 155-millimeter range, and use the existing railway gun projectiles. Had the armi- stice not intervened it is not improbable that this solution would have been adopted. 10 11 12. This is the first mount observed on which the ammunition is stored on the car. It will be observed on Plates 8, 9, and 10 that a steel ammunition storehouse has been constructed on each end of the Pr.ATE 8 ARRANGEMENT OF MAGAZINES ON EACH END OF CAR. car body. No special provisions were necessary for the handling of the ammunition, since two men could easily handle a projectile in a tray. The car body is of special design, steel throughout, and Plate 9 OUTRIGGERS AND WORKING PLATFORMS IN POSITION FOR ACTION. again includes the hinged extension working platform on each side in the center. It is believed that the trucks are simply standard rail- way trucks of quite heavy design. 12 13. System, of anchorage.— On Plate 9 the mount is seen anchored for service. To the best of the writer's knowledge there is no other mount in the French service which has the central anchorage mecha- nism so close in. The screw housings are attached directly to the side of the car. The screws are forced down on iron caps resting on wood pads or floats. In addition there are eight rail clamps — four in the center of the car and two at each end — to prevent too great vibration of the car on recoil or counterrecoil of the gun. This system of anchorage seems to have answered quite well, for the guns and mounts saw heavy service. Plate 10 READY BX)E TRANSPORTING. 194.4-MILLIMETER HOWITZER, MODEL 1875, 1876. 14. This mount," Plates 11-13, is simply an improvisation. It was made up by utilizing coast-defense guns and their carriages and mounting them on railway trucks. The carriage affords top car- riage recoil and is mounted on the truck without provision for traverse. The gun tube is of a very old model and consists of a cast- iron body, at the breech end of which a liner is inserted, and steel hoops are shrunk on the outside. 15. RecoU nvechamsm. — This mount as noted above has top car- riage recoil. Counterrecoil is by gravity. The hydraulic buffer cylin- ders, Plate 14, are about 9 inches outside diameter by 6 feet in length and are attached to the car body just beside and under the inclined rails. The piston rods are 2 inches in diameter and are attached by means of 2-inch pins to the gun carriage near the rear end. The gim carriage rolls in recoil up a pair of rails and apparently can recoil a distance of about 4 feet. The four wheels on which the carriage is supported are 16 inches in diameter by 4 inches in width and are mounted on axles 6 inches in diameter. 13 14 i-l 15 16 16. Elevating Tnechanism. — The elevating mechamsm is in dupli- cate, including a slow, heavy mechanism for elevating the piece and supporting it when fired and a rapid return naechanism for use in loading. This elevating system might be termed an "indirect Plate 14 GUN CARRlAGt END OF ROLLER SHAFT. RAIL RECOIL CYLINDER CONNECTION A FIG. I. (^ Gk -|8'-J s COUNTER RECOIL CYLINDER B FIG. Z. ^- TWO SUCH Bf?flCKETS a TWO SUCH CLIPS. GUN CARRIAGE ABOUT 4 ADJU5TMtNT .£5 D. RAIL. CAR BOBY FRONT. END COUNTER RECOIL CYLINDER CONNECTIONS.-C , FIG. 3. RECOIL MECHANISM OF 190 AND 240 HOWITZERS. system " inasmuch as the mechanism merely supports the breech end of the gun and the operation depends upon the fact that the gun has a breech preponderance. This mechanism, because of its simplicity of construction, is worthy of consideration; it seems crude but it 17 works. The main elevating mechanism consists of two plates .625 inch thick, Figure 1', Plate 15, pressed to the desired shape, with a steel elevating rack riveted between them. This rack arrangement is hung directly under the gun from two axles fixed in the two side frames of the gun carriage just below and to the rear of the trun- nions. The ball rest, shown in Figure 1, bears against the underside of the gun at the breech end and holds it at the desired elevation. This rack meshes into a worm which, through a worm wheel and 18 another worm, a gear and an idler gear, leads to a iiandwheel. Most gear ratios are given on the sketch. It should be added that the rack has approximately 1.25 teeth per inch and the pinion on the 4-inch worm shaft has 14 teeth. The ratio of movement is not con- stant, but one turn of the handwheel moves the gun through ap- proximately 0.14 degrees. No antifriction device is employed and trunnions, attached directly to the gun, are 18 centimeters long by 20 centimeters in diameter and rest in semicircular trunnion bear- ings without trunnion caps. 17. The rapid return mechanism is illustrated in Figure 2 of the same plate. This is similar to the main mechanism, but is located on one side only, and its train consists of rack revolving about auxiliary bearing, pinion, gear, pinion, and handwheel. This mechanism sim- ply lifts the breech of the gun off the main mechanism through a roller carried by a band around the breech. After loading is ac- complished the gun may be dropped back upon the heavy mechanism which has been left set at the required elevation. One turn of the handwheel moves the gun through approximately 5 degrees in eleva- tion. 18. Traversing mechanism. — This design of carriage has no pro- vision for traversing the gun. It is necessary to operate the mount on a curved track, where any desired traverse ma,y be obtained or on a special platform made up of heavy timbers. A platform was used with success late in the war. 19. Gun carriage. — The gun carriage is of extremely simple con- struction, being composed of approximately 10 parts, almost all of which are of pressed sheet metal. The sides are .875 inch steel plates with 4-inch flanges. The top carriage is supported on four wheels, as noted under " Recoil Mechanism," and rolls up an inclined track formed on the girders of the car body. The recoil cylinders are located along these girders just outside of and below the rails. 20. Railway car 'body. — The design of this car body seems to be unnecessarily complicated. Apparently two side girders of the desired shape, mounted on two structural steel beams, carrying the wheels and axles, might be subtsituted for the body used; at the ends any desired width might be given to the body for the necessary operation of the gun. Provision is made for placing road trucks ander both the front and rear ends, thereby converting the mount into a tractor-drawn mount. For somewhat similar road equipment see Plate 53. 21. Anchorage. — During firing the mount is supported on three cross beams or sleepers extending across the track, one in front and the other two between the axles. These beams are of wood, but are shod with steel plates and provided with a handle and socket at each end, 19 Plate 16 I BEAMS. REST FOR JACK- CAR BODY SUPPORT. FIG. I .75 D.- FIRING SUPPORT. FIG. a. r — 7""- f^ •J I • -4 .t i C__|_o^ ■? 1 *-|£ >■ TRACK EQUIPMENT FOR THE 190 AND 240 HOWITZERS. 452—22—3 20 Figure 2, Plate 16. i|Six 4-inch screws are provided in the position shown in Figure 1 of the same plate. The sleepers are placed across the rails under the screws and the latter run down until the weight of the mount is partially transferred from the wheels to the sleepers. Plate 17 BLOCK i 'Z.5'.675 -.75 PIN. ] RAIL CLAMP. -1. FIG. I ,3. D. 1.5 D. ^' Z.5 D. T — [j-y -RATCHET -108. h^-^1 TIE BAR. riG. a.. Il- ■ H 4. 62 5 TIE BAR BRACKET FIG. 3 DETAIL SKETCHES OF RAIL CLASIP. To prevent the mount sliding along the track on firing, a rail clamp, Figure 1, Plate 17, is provided. It is attached to the outside rail of the curve and is connected to the car by means of the tie bar, Figure 2. The eye end of the bar is connected to the clamp and the 21 hook end to the bracket on the front of the car, Figure 3. It will be noted that half of the pin is cut away ; it is shown in the position for inserting the hook ; half a turn to the left locks the hook in place. The rail clamp usually slips a little at the first few shots, but when the slack is taken up the mount is held in place. 22. Trucks. — The railway car itself is really the truck. Cast- steel boxes slide up and down in the slots of plates riveted to the car body and support the latter through semielliptic springs. 23. Amnvumition supply system. — At the rear end of the car an ammunition table, Plate 11, is built in place. The projectile is trans- ferred to it from the ground by means of the jib crane made of a 6-inch I beam. Two sockets are provided, so that the crane can be mounted on either side of the car. A tray is provided of sufficient length to reach from the ammunition table into the breech of the gun; the projectile is slid forward on this tray and rammed by two men. 194.4-MILLIMETER HOWITZER, MODEL 1875-76 ON CARRIAGE, MODEL 1917. 24. This mount, Plates 18-19, is of the same general type as the preceding though it is not adapted for road transportation and the frame of the car is horizontal and straight instead of inclined and broken. The gun isi the same, as well as the top carriage, both of which were removed from coast fortifications. This mount repre- sents an improvement over the preceding in the sturdiness of the car. 25. Recoil mechanism. — This mount as the preceding has top-car- riage recoil. The top carriage consists of triangular structural steel side frames connected by front and rear transoms and mounted on four rollers, each about 15 inches in diameter. These rollers rest on two horizontal metal rails mounted on the top of the car body, and the top carriage rolls back along them for a distance of about 42 inches. The recoil cylinders are two in number and are located one on each side of this car body. Figure 1, Plate 14, just outside of and below the rails on which the top carriage rolls. The carriage is returned to its normal position by either a steel spring mechanism. Figure 2, Plate 14, or by rubber bands carried in the same type of cylinder and connected in the same way. The novel experiment of using rubber bands came about because of the extreme difficulty from the breakage of the steel springs in cold weather. Eacji of the cylin- ders carried 12 cotton covered bundles of 700 rubbpp bands each. The counterrecoil with rubber bands is slow but quite 'satisfactory and there was no trouble thrbugh breakage. 22 26. Elevating mechanism. — See same for the preceding mount, and Plate 15. 27. Trawersing m^cJianism^. — T^iis material is designed to fire from a curved epi, as shown on Plate 18, and no traversing mecha- nism is provided. Further, the piece is so light that the French have improvised a firing platform, Plate 19, which can be installed more quickly than an epi and which allows 60 degrees traverse. This con- sists of a wooden platform about 5.5 meters square, with a half circle of railway rail 2.4 meters in radius spiked down on top of it. A small portable turntable or pivot is provided, to which the weight of the mount can be transferred by means of the jack screws and sleepers. The mount is brought up on the main track, and a tem- porary branch track at right angles is laid to and over the firing platform. The mount is transferred to this track by jacking it up, Plate 18 CURVED BPI FOR NON TRAVERSING MOUNTS TO OBTAIN AZIMUTH. putting it on the pivot, turning it around, and lowering it on the branch track rails. It is then rolled onto the firing platform until its center of gravity is just over the center of the semicircular rail mentioned above. Wood stringers are placed between the wheels, the sleepers are jacked down onto them, and the temporary branch rails are removed. The car is anchored to the semicircular rail by guys. After the pivot is replaced the mount may be traversed after being lowered to it. For firing, the mount rests on the stringers, through slefepers and jack screws, while the guys transfer the hori- zontal recoil forpe to the semicircular anchorage rail. For traversing, the weight is transferred to the "pivot, the entire mount is turned by hand or by turnbuckles and guys, a,nd then let down. 28. Gvm, carriage. — See Same for preceding mount. 29. Railway car hody. — The railway car body, Plate 19, is really a simple 4-wheel truck built up of structural shapes and rails. 23 24 The wheels are 1.05 meters in diameter and are connected lo the car body by semielliptical springs, Plate 20. 30. System, of anchorage. — When the mount is fired from a curved track the operation is exactly the same as that of the preceding mount. The jacks are shown in considerable detail on Plate 20. The . special platform explained under " Traversing mechanism " affords all the necessary anchorage. This platform requires from one to two days to install. 31. Difjiculties iiwolved in service. — The turntable, Plate 19, pro- vided for use in connection with the firing platform, is so small that the greatest care is necessary in using it. On one occasion when a mount was being installed .during the night some days before Plate 20 SCREW JACKS FOR CLAMPING DOWN ON FIIlING PLATFORM BETWEEN RAILS. the beginning of the St. Mihiel offensive it overturned because of lack of proper care in placing- the pivot. This is an extreme case, of course, for lights were absolutely forbidden on this occasion. 194.4-MILLIMETER HOWITZER, MODEL 1875, 1876, 1878, ON THREE-AXLE MOUNT. 32. This mount, Plate 21, is in general the same as the preceding. It has been improvised from a seacoast carriage and gun and is of the hydrogravity type. The railway car body is of wood, however, and is su]oported on three axles instead of two, as in the preceding two mounts. Three sleepers are used in firing, and the elevating mechanism, scheme of anchorage, recoil mechanism, and ammunition supply system are the same as previously described. 25 26 194.4-MILLIMETER GUN, MODEL 1902. 1887, 1893, 1896, 33. This is another mount improvised from a seacoast gun on a gun lift, 360-degree traverse type of coast carriage. The exact degree of traverse that can be used on the railway mount is not known; it is probably not more than 10 degrees on either side of the line of the track, however, since no special provision is made 27 for firing at wide angles. The car body is of wood and in firing is supported on four wood sleepers. Eail clamps and the guy rod previously described are also used. There are no features that seem worthy of description in detail. The mount is shown on Plate 22. 194.4-MILLIMETER GUN, MODEL 1870, 1893. 34. Examination of Plate 23 will show that this mount is quite similar to the preceding. The gun is shorter and the top or gun 28 carriage is slightly different in design. The railway car is almost iden- tical, having five axles, four sleepers, similar rail clamps, and the same guy rod. The car body is constructed of v^ood. 194.4-MILLIMETER GUN, MODEL 1870, 1893, ON THREE-AXLE MOUNT. 35. The seacoast carriage used in making up this mount, Plate 24, is of the gun-lift type, but with its base ring would have made so high a mount as to exceed the railway clearances, hence the omis- sion of any traversing arrangement. The car body is principally of steel, but with Avood operating platforms. The mount must of course be operated on a curved track and is anchored by means of the already described type of wood sleepers and tie rod. Most of the features of this mount have already been described under other guns. 194.4-MILLIMETER GUN, MODEL 1870-1893, ON DOUBLE TRUCK MOUNT. 36. This mount, Plates 25-28, is again an improvisation from a seacoast gun and carriage. The gun consists of a cast-iron body with a steel liner and two rows of exterior hoops. The marine type of interrupted screw breech mechanism is used, and the firing mechanism is of the percussion type. 37. Recoil mechanism.. — ^The recoil mechanism is of the top car- riage hydrogravity type. The recoil cylinders are two in number and the top carriage recoils up the inclined rails of the chassis about 0.90 meter. The top carriage rests on the rails through four rollers. 38. Elevating mechanism. — The elevating mechanism is attached to the top carriage and recoils with it. It consists of a rack of about 0.80 meter radius, a pinion, two sets of bevel gears, and a handwheel. One turn of the handwheel (radius about 30 centimeters) moves the gun approximately 3 degrees in elevation. The maximum elevation obtainable is 30 degrees. 39. Traversing mechanism. — The chassis, or racer, on which the top carriage rolls, is supported in turn on four large rollers with axes ar- ranged radially, Plate 27a. These roll on a suitable machined track on the base ring. A circular rack is provided on the base ring, into which meshes a pinion on the end of a vertical shaft carried by the racer. The traversing handwheel is mounted on a horizontal shaft and connects with this through bevel gears. The traverse allowed by the mechanism is 360 degrees, Plate 27, but it is probably impossible to realize that, due to character of anchorage, etc. 29 < 30 31 o O e c! -< u Q K O IS 32 33 40. Gun carnage. — The gun carriage is a coast defense type and of model of 1886. It includes the cast base plate, racer with two side frames and transoms, and the various mechanisms above de- scribed. The rotating portion of the carriage carries a cab or turret of sheet steel for the protection of the personnel. 41. Rcdhoay car hody.— The railway car body is merely a simple steel frame flat car. It is provided with a siheet-steel housing or pas- sage at each end extending between the gun turret and the end of the car. 42. Anchorage. — ^The anchorage ar- rangements include two metallic stringers which can be lowered onto the rails by jack screws, four exterior jack screws placed near the ends of the stringers and outside of them, which can be brought to bear on footplates set on the roadbed, and four rail clamps situated at the ends of the stringers, which grasp the rail and hold the mount down. It is understood that the mount is apt to slip somewhat when fired along the track, but the anchorage appears to have been reason- ably satisfactory. 43. Ajmnimition supply system,. — This mount is used with an am- munition car having an end door, Plate 26. A trough or slide is pro- Plate 28 TRAVERSING ROLLERS AND GEARING. GUN AND MUNITION CARS IN PLACE AND ANCHORED FOR FIRING. vided through the housing at he end of the mount, with extensions which can be run in under the trolley hoist in the ammunition car and up through a hole in the back of the turret to the breech of the gun ; the shot is lowered into this tray, pushed along, then rammed up into the gun, which loads at a considerable elevation. The turret, of course, must be brought to zero azimuth for loading. 34 44. Difficulties involved in the service. — It is not known why this mount was so carefully annored. Presumably the armor was later learned to be of little service. At any rate its presence would seem to hamper considerably the operation of maneuvering and loading the piece. It would seem also that the anchorage scheme might easily give trouble, or at least that frequent readjustment would be necessary. 200-MILLIMETER HOWITZER. 45. This type of mount is one which was constructed by the Schneider Co. for the coast defense of Peru in 1910. The mounts Plate 29 TbTaf Wfeight 84330 Lbs. Weight Per Foot Run 0\^er Bumpers 2150 Over Base e54o Weight of the Gun aiso E/evation -5 to Go" Traverse 3 OF 1876 ON TWO AXLE CAR. with a steel liner and steel hoops at the breech end, and is 20 calibers in length. All of the characteristics of interest of the various mechanisms have already been described in detail. * See explanation of numbers at head of table of contents. 42 240-MILLIMETER HOWITZER, MODEL 1876, ON CARRIAGE MODEL 1917. 56. This mount, Plate 36, is in general similar to the preceding. It has three axles instead of two, however, and the three jacking beams are suspended between the trucks instead of under the truck bodies or frames. The howitzer is of the same model, hence the mount perhaps represents an improvement over the previous de- sign. It will be observed, likewise, that there is an ammunition Plate 36 HI — m a 240-MM. HWrrZBR MODEL OF 1876 ON CARRIAGE MODEL 1917. hoist attached to the side of the gun carriage, whereas on the pre- ceding mount an ammunition table is provided at the rear end of the car body. 240-MILLIMETER HOWITZER, MODEL 1876, ON G. P. C. MOUNT. 67. This mount. Plates 37-38, represents the highest develop- ment of this type of design during the war. A large number of them were in the hands of American Railway Artillery Reserve and were used in the St. Mihiel offensive and from that time on in various parts of the line. They seem crude, of course, but under the circumstances they proved worth while, since they could be served rather rapidly and had the fair range of 13 kilometers. 58. Recoil mediamism. — The recoil mechanism of this mount is closely similar to that of the IDl-millimeter howitzer mount, Model 1917. It is of the top-carriage type with spring counterrecoil. The two hydraulic cylinders are located just below the carriage rails and outside the side sills of the car. They are about 9 inches outside diameter and 6 feet long, with piston rods about 2.5 inches in diame- ter. The two spring recuperators are detachable and when not in use are carried on the side of the car. Each recuperator is attached 43 by a bolt to the forward end of the car body and by another bolt through the piston rod to a hook on the forward end of the gun car- riage. This latter bolt is then drawn back by a nut and the recuper- ator can not rise out of the hooks. For traveling, turnbuckles with hooked rods in each end are substituted for the spring recuperator and the carriage is screwed up firmly against the stops. Details of the recoil and counterrecoil mechanism are shown on Plate 14. 59. Elevating mecJumdsm. — The elevating mechanism is the same as for the 194.4-millimeter howitzer mount, No. 5. 60. Traversing mechmdsm. — ^It is not possible to traverse the gun on its carriage or the top carrialge on the car body. The mount may be traversed either by moving it on a curved track or by placing it Plate 37 Total WeigW When Firing aasso* Efevation +5*To+40° " " Transported on Rood ss.sso Traverse on Curved TracK " " Transported on R.R. 90,400 Weight oy Projectile 359** Weight "Per Toot Run Weight of ftowder 29* Over Bumpers 37 lo* Initial Velocity 47e Ft. Ffer Sec. Over Wheel Base (0700* Range Maximum 14,220 Yds Weight of the Gun 35,330* 240-MM. HOWITZER MODEL 1876, ON G. P. C. MOUNT. on a firing platform of the type described under mount No. 6, on which platform a traverse of 60 degrees may be secured. 61. Gim carnage. — The top carriage is composed of two cast-steel, triangular side frames, 1.25 inches thick with 3-inch flanges, joined by front and rear transoms, Plate 38. Steel trunnion bearings are riveted to these frames, but no trunnion caps are provided. The top carriage is supported on four wheels about 15 inches in diameter by 6 inches thick and mounted on 8-inch axles. 62. Raihoay car hody. — The body of this car is most simple in design. It is composed of two 24-inch I beams on top of which are located the rails on which the top carriage slides in recoil. These beams are connected by transoms and carried on three structural steel boxes in which the wheels and axles are mounted. Provision is made for removing the front wheels and axles and supporting both 44 the front and rear ends on road trucks so as to convert the whole into a tractor-drawn mount. The road wheels are shown in dotted lines on Plate 37. A similar arrangement for road travel is shown for the 240-millimeter gun, Model 1903, on Plate 53. 63. Anchorage. — The system of anchorage is exactly the same as that of the 194.4-millimeter mount, No. 5. 64. Trucks. — The car body really constitutes a single 6-wheel truck. The center axle is situated unsymmetrically, forward of the mid- point between the other two. The wheels are 0.80 meter in diameter and the car is supported on them through semielliptic springs. 45 240-MILLIMETER GUN, MODEL 1893, 1896, ON ST. CHAMOND MOUNT. 65. This mount, Plates 39 and 40, consists of a coas-t-defense gun and its top-carriage recoil, all round traverse carriage mounted on a specially constructed drop-frame steel railway car. It has been familiarly known as the •' Colonies " mount and was made up early in the war for the 305-millimeter gun. 66. Gun. — The gun is a steel tube 40 calibers long. It is provided with trunnions 12 inches in diameter by 8 inches long, approximately, mounted by means of a trunnion band about 4 by 24 inches. Pro- vision is made on the side of the gun carriage for adjusting the center line of the trunnions. The breech mechanism is the Manz screw type with interrupted threads and is operated by a handwheel. Obturation is secured through the use of. an annular copper obtu- rator. Plate 39 LEFT SIDE ELEVATION 240 GUN, MODEL 1893-1896. LOADING RIG SUPER- STE.DCTURE KNOCKED DOWN FOE CLEARANCE WHEN TRAVELING. 67. Recoil system. — This mount, as mentioned above, has top- carriage recoil. Counterrecoil is by gravity. The gun is suspended in a heavy cast saddle, which in turn is supported on tlie rolling gun carriage. This recoils up rails rising toward the rear with an incli- nation of 4 degrees. These rails are carried on a racer in which the recoil cylinders are installed. These cylinders are two in number and are about 15 inches in diameter. Each is attached inside the front of the racer at a point about 42 inches below the gun by means of a 6-inch pin, about which the cylinder is free to revolve in a verti- cal plane. Each piston is similarly attached to the gun carriage in such a position that its axis is approximately parallel to the inclined rails. This form of attachment, however, makes the buffer self- aligning and more distinctly a separate mechanism than on any other mounts examined. On this account continual inquiries were made as to whether the design had ever been found defective. All of the officers who had handled artillery of this type were positive that no difficulties had ever been experienced with the buffers. 46 68. Elevating mechanism. — The gun is normally carried on very small radius auxiliary trunnions which rest in corresponding auxil- iary bearings. These are supported at the center of a heavy lever, one end of which rests solidly on the top carriage, while the other is supported by adjustable Belleville springs. Under the shock of firing, the spring-supported end drops, letting the gun descend slightly anrd-aUowing the main trunnions to seat in their bearings, which are purposely left with a small clearance. This antifriction device greatly reduces the labor of movingthe gun in elevation. 69. The gear train of the elevating mechanism is unusual in that the operating handwheel and some other parts do not recoil with the top carriage. The arrangement, which is as follows, can be traced out on Plate 40. An elevating rack with inside teeth is at- tached to the breech end of the gun by a 1 by 5 inch strap. This rack has a 2-inch face and meshes with an idler, which in turn meshes with a pinion. The shaft of this pinion is provided with a slip friction device and bevel gears. From this pair of gears a diagonal shaft leads down alongside the top carriage to another pair of bevels, also in bearings attached to the top carriage. The sec- ond of these bevels slides along a stationary horizontal shaft. This shaft is provided with a worm wheel and is operated by a worm, sprockets, and chain leading to a handwheel. Exact figures on the gearing are not available, but it appears that the gun is elevated between 1 and 1.5 degrees per turn of the handwheel. The elevation can be varied from 15 to 35 degrees for firing across the track, but parallel to it certain interferences with the car body limit the eleva- tion to 29 degrees. 70. Traversing mechanism. — A traversing rack 6 inches wide, ex- tending around the carriage, is bolted to the outside of the racer at its bottom. At the rear a pinion on a vertical shaft meshes with the rack. This shaft is carried in bearings fixed to the car body and a gear train leads to two cranks located on each side of the car body just at the forward end of the " drop " portion and clearly seen in the photograph, Plate 40. Three or four men are required to operate this. The carriage can be traversed 360 degrees and is provided with a lock for fixing it in the position of zero traverse for loading or traveling. 71. Gun carriage. — The gun carriage is the 305-millimeter sea- coast carriage. Model 1899, modified to adapt it to the smaller gun. The rolling top carriage is made up of two main parts. The one is the saddle in which the gun is supported, which in turn is fixed on the heavier frame of the rolling carriage. The body of the main part is a two-piece casting bolted together in the center. The car- riage rolls on 10 rollers, 6 on each side, 15 inches in diameter, with 47 48 5-inch shafts. The rails are 8 inches wide, and, as before mentioned, they are inclined at 4 degrees. On the front of the top carriage are two buffers, about 4 inches in diameter, which project about 3 inches and meet corresponding buffers on the main carriage and serve to cushion counterrecoil. The side frames of the main carriage are cast- steel beams of I section ; these are connected in front by a heavy steel transom to which the recoil cylinders are connected, and they rest in turn on the racer to which they are bolted by edght 1.5 inch bolts, each. The racer rests on conical traversing rollers and is provided with a center pintle. In order to lessen the traversing effort a spring-supported bearing is arranged under this pintle so that a large part of the weight of the rotating mass is carried at this point. At the bottom of the racer, just above the traversing rack, is attached a brass azimuth ring 2.5 inches wide by .187 inch thick. The ring is in eight sections, and is attached to the racer by four screws per section. It is separated from th'e racer by means of bushings around the screws. The base plate, with the lower conical roller path on its upper surface, is a single casting and is bolted to the car body by sixteen 3-inch bolts. 72. RaMway car hody. — The car body is composed of two built-up side girders, having .625 inch webs and flanges made of 3 by 3 by .5 inch angles and two .75 by 12 inch flange plates running the entire length of the girders and three plates in the horizontal sec- tion at the center. These girders are braced laterally by means of six built-up transoms in the horizontal section in addition to heavy transoms at the ends and latticing on the inclined sections. The bottom of the side girders is about 15 inches from the ties at the cen- ter and 4 feet 6 inches at the ends. The depth of the girders in the center is about 36 inches and at the ends 20 inches, and the total length about 40 feet. At each of the four corners of the car are attached heavy cast brackets, Plate 40, for the outriggers, all of which can be seen at the sides of the car at each end. The long and short outriggers shown on Plate 41 are provided for use on either level ground or fills. Inasmuch as extreme difficulty is experienced in holding this car when fired normal to the track, it would seem that the outrigger brackets are attached to the car too far from the center. The car is inclined to whip even more than the American 8-inch mount. 73. Anchorage. — The provisions for anchoring this mount are shown on Plates 41-47. It was learned from the battery commander that the original provision for anchoring the car simply by means of outriggers and a rather simple type of firing platform was un- satisfactory. As a consequence the provision for bracing the car by means of five screws and hooks, Plate 42, and additional beams on each side have just been added. The guns have not been in action 4LI .09 JO 3TS/v^' ^n-/2 or\ AJf J.^S- af333/3f^no\ ■wet/ JA'J/*aSM/>^a'^J a'3l HOI/SX 37B/toO 50 51 Plate 43 OUTRIGGER STRUT SEAT -rt *"■!* ~Z.xl.7SHN6LE 45: ■ 2d 10 ■!« is-y 10. J" 10. •!• /o «|8.7J !• /a «7. p ^^^w^ m O { o I o I o r o I is * I o I y ^^-^^^ y^^Af l.ZSx^t.STEEL PLDTEi OUTRIGGER FLOAT DETAILS OF 240-MM. GUN, MODEL 1893-1896. 452—22 5 52 Plate 44 rr^./. ,s .ers/iOi.£s £>fr^/l C OUTISi66£:J^ C^3T/NG ^(g-^ STS'/foi^s l>£T^/l >* ^JE^T roe £A/D .S7/?UT OUTRIGGER FLOAT DETAILS OP 240-MM. GUN, MODEL 1893-1896. 53 f -^-- *'^v. /> N« 4 i;^ ^ %/ 1<^ /'■'r/^ /"'"'// Iff ., "/ r>4 55 since the extra braces have been provided, hence no data is available with reference to their practicability. 74. On Plate 41 it will be noted that outriggers of two lengths are provided. These outriggers are intended to be attached to the same brackets and are used according to the nature of the ground at the firing position. To avoid unnecessary excavation the short strut is used for level ground and the long one for fills. There is a serious (luestion as to whether the base or float provided for this mount is as effective as that provided for the American 8-inch. On Plate 43, Figure 1, is shown the beam with its socket, which is used with two of the cast blocks. Figure 1, Plate 44, as a base for each strut. When the gim is fired from a double-track railway the steel block is so made as to set over the near rail of the adjoining track, Plate 41. Plate 47 V. . 3'-f-'- j-t^^y^^ <-<■<: \^IZ-^]^3a: J- 30- -f 30-'- -T -^ 240-MM. GUN, MODEL 1893-1896, TRACK BEAM DETAIL FOR ANCHORING CAR. When the base is placed on the ground the cast blocks rest on the platform, Figure 2, Plate 43, which in turn rests on sand or crushed stone. Provision is made on the strut, Figure 1, Plate 45, for taking up the play as the base settles into the ground. 75. The firing platform provided for carrying the weight of the car and bracing it against motion in the direction of the track requires 12 hours for installation. On Plates 42, 46, and 47 are shown the stringers that are placed on the ties between and outside of the rails. Figure 3, Plate 43, is a detail of the filler block used under the wedges. Figure 2, Plate 42 ; see " D," Plate 41. On Plate 45, Figures 2, 3, 4, and 5, are given the details of the bracing mechanism of which an assembly is given on Plate 42, Figure 1. This is the addi- tional provision that was last made for bracing the car. No data is available on the success of its use. 56 76. Trucks. — These trucks are designed especially for the mount, Plates 39 and 40. The body is made up of two side plates 1.25 inches thick with suitable transoms; the brakes apply only to the center four wheels. Identical ammunition supply platforms and elevators are built on both trucks. 77. Ammunition supply system. — No special ammunition cars seem to be provided for this mount ; both powder and shell are carried in standard box cars. On the end of the loading platform, Plate 39, is a steel ammunition cabinet divided in twenty-one 10 by 10 by 30 inch sections, open in front. The sections in the central vertical tier are open at the back as well as at the front. On the top of the cabinet six shallow troughs are provided, in addition to the central receiving trough, for the storage of projectiles. An additional shallow trough about 9 feet long is provided to reach from the central top trough to the breech of the gun. The projectile is slid forward on this trough and rammed by hand. The gun must be returned to minus 1 degree for loading. On each truck will be seen the framework into which the elevator is built, at the top of which is a platform for the men who transfer the ammunition from the elevator into the cabinet. The elevator contains four trays, Plate 40, the top tray for projectiles and the bottom three trays for powder. In line with these trays when the elevator is down are four other trays, built on the trucks ; the top tray of these four runs to the back of the truck Avhere the projectile may be placed on it. The bottom three trays are short and the bags of powder are lifted up from the ground by hand and placed on them. When the elevator is down the projectile and three bags of powder are slid forward on the elevator trays. The elevator is operated by means of a simple windlass, the rope running up and over a pulley at the top of the frame. When the elevator is up a latch holds it in place. When the projectile tray is in line with the top tray of the cabinet the projectile and three bags of powder are slid forward onto and into the cabinet by the men standing on the rear platform. 78. Maintenance. — To date the French have not found the problem of maintenance on this mount serious, although the mount can not be considered satisfactorily successful because of the difficulty that they have experienced in anchoring it properly. As yet very little shop- work or field repairs have been necessary on the mount as originally provided. No parts have been broken or damaged except acci- dentally. 79. Difficulties involved in the service. — The only difficulties that the battery commanders handling these mounts report are in connec- tion with the anchorage system. The system is unsatisfactory. To date it has not been possible to use the gun satisfactorily at a con- 57 siderable angle to the track. Inasmuch as it is almost always desired to use a mount of this type at short notice, 12 hours is too much time for the installation of the firing platform. 240-MILLIMETER GUN, MODEL 1884, WITHOUT TRAVERSE. 80. This mount, Plate 48, is again one of the familiar improviza- tions made up to accommodate a seacoast gun and its carriage. It has a few features that are unusual. On the front end a windlass is mounted for pulling the mount back into position after firing. There Plate 48 240-MM. GUN, MODEL OP 1884. are four friction firing beams mounted in this case between the axles instead of in conjunction with the trucks as in several other mounts. 240-MILLIMETER GUN, MODEL 1884, WITH TRAVERSE. 81. This improvization, Plate 23, is identical with No. 9 for the 194.4-millimeter gun, Model 1870, 1893. 240-MILLIMETER GUN, MODEL 1870, 1884, 1887. 82. This mount, Plate 49, is of the same general type as that for the 194-miUimeter gun, Model 1870, 1893, No. 11, being made up of an old seacoast gun and mount, with top carriage recoil arid all-round traverse, mounted on a two-truck car with jacks, struts, etc. 83. Gvm,. — The body of the gun is of cast iron, and it is reinforced with a row of hoops. It contains inside a steel tube also reinforced by a row of hoops. The breech mechanism is of the marine type, similar to that of the 19-centimeter gun. Model 1870, 1893. The firing mechanism is of the percussion type. 58 84. Elevating mechanism. — The elevating mechanism permits of elevation from minus 3 to plus 30 degrees. The mechanism is mounted entirely in and constitutes a part of the rolling top- carriage. 85. Anchorage. — The anchorage arrangements include four me- tallic stringers, which can be lowered onto the rails by jackscrews, Plate 49 ^\ ^\ ^\zm ft>///'/'"/m/y!"-'J'i^!-?^''>'y/WAA''A-!'.-'^y^»lj-'^>/>'>'///^ y^J'^',- ''yA>v^r///4rf/////^J 240-MM. GUN, MODEL 1870, 1884, 1887, ANCHORED FOR 360° TRAVERSE. and four exterior struts, which swing out from the sides of the car at points near the ends of the two center stringers and are provided with jacks at the ends. For firing, the stringers are first lowered to the rails and the mount is jacked up on them slightly. The rail clamps, which are provided on the underside of the stringers, are next tightened against the rails. The exterior struts are then swung Inside dacK Screw BracKat Folded Transverse LocKing Beams Clomp Screw- ,#V>/WW Plate 50 BracKer Hinge Folding BnaoKets ae JaoK Screws Emplacement BlocKlng Olamp Shoes ANCHORAGE FOR 240-MM. GUN, MODEL 1870, 1884, 1887. out and braced in place, and the jacks at their ends are screwed down to a bearing on floats placed on the ground beneath them, Plate 50. 86. Ammnmition sufpVy system. — The mount is provided with an ammunition rack at each end. Another rack, capable of holding several shells, is mounted at the rear end of the carriage and turns with it. A shot track serves to convey the shells from this rack to the gun. 59 240-MILLIMETER GUN, MODEL OF 1903. 87. This mount, Plates 61-54, comprises a double recoil carriage carried on a car arranged for standard gauge, narrow gauge, and road transportation. In operation it is anchored to a self-contained ground platform. 88. Gun. — The gun is a steel tube provided with a breech mech- anism of the revolving block type, known in France as " System Canet." The breech block is a hemispherical sector revolving about tin axis through its own center and through and perpendicular to the center line of the gun. The sides are parallel surfaces per- pendicular to this axis, and are provided with circular grooves which Plate 51 felE 29 6.7G 105,770* Trovense on Curved IracK Tbral WeiqW- Weight Rsr Foot of Length Weight of R-oJectile 3 52.* Over Bumpers 3,5ioo»* " " Ohorge 53. s* " Over Foundation ■^710* Initial Velocity siz. Ft. Ffer Sec. Weight of the Gun 33,200* Range MaxiMUM 17,500 yds. Elevation + lo'to -h 35° 240-MM. GUN, MODEL OF 1903, SHOWING STANDARD AND NARROW GAUGE TRUCKS. slide around in similar grooves in the gun breech. The entire block is pierced by a hole in the center of the diameter of the powder chamber. To open the breech the block is turned about its axis until this hole is in line with the bore of the gun. To close, the block is turned 90 degrees. The block is arranged to operate automatically and to eject the powder case. Semifixed ammunition is used. The firing mechanism is of the percussion type. 89. Recoil mechanism. — This carriage has a double recoil mech- anism, a combination of cradle and top-carriage recoil. The cradle- recoil system is provided with pneumatic counterrecoil, and the recoil length is 0.62 meter. The top-carriage recoil system has gravity counterrecoil, and the length of recoil is 1 meter. 90. Elevating m£chanis?n. — It is possible to elevate the gun to a maximum of 35 degrees. It is loaded at plus 10 degrees. Tlie mech- 60 anism has a ratio of 1 degree of elevation per turn of the handwheel, and embodies an antifriction device to reduce the effort in elevating and depressing the gun. 91. Traversing mecharnhm. — This mount is provided with car body traverse. The car and trucks move on a base plate, allowing 7-degree traverse on each side of the center line. The base plate is arranged with a pintle in front and the car has two rollers behind. 92. Ratkoay car iocly. — The railway car body is little more than a simple flat car built of structural steel. It is provided with a spe- cial hoist, a sort of shear leg derrick, Plates 53 and 54, by means of which the gun and cradle can be removed from the carriage and placed in another car for transport. 93. Anchorage. — ^As noted under traversing mechanism, this mount is provided with a base plate on which it is supported in firing. For traveling this is held to the car by four bolts. In placing the gun Plate 52 Hydnauljo BraKe on Elei/oTing Gear) N TruoKs Z3MZ irvJO, p| Aba^e Rails Base Plate — I 4xie at Normal Height Traversing Roller 240-MM. GTJN, MODEL OF 1903, BMPLACED FOR 14° TRAVERSE. for action it is customary to run the mount to the nearest point on a standard-gauge track and to convey it to the firing position on narrow-gauge track or by road. This firing position consists of a flat top bank of well tamped earth, or of stone or timber, so arranged as to constitute a flat foundation with its upper surface 14 centi- meters above the rail. The narrow-gauge track, which starts with a turntable between the standard-gauge rails and leads off at right angles, is laid through this platform with the foundation material taken out above the rails. On arrival at the foundation the mount is lowered so that its entire weight rests on the latter through the base plate. The base plate is prevented from slipping back on the foundation by means of two guys with turnbuckles which are at- tached to deadmen buried in front of the mount. 94. Trucks. — This mount is pi'ovided with both standard and nar- row gauge trucks. The standard-gauge arrangement consists of two 61 I Q H > O a H Z P o H V P a Q I O O Z P O p o es o b tf ■ 62 63 axles which can be raised and lowered. The narrow-gauge arrange- ment consists of two independent narrow gauge trucks attached to each end of the car outside of the standard-gauge axles. These can also be raised and lowered. Jackscrews are provided on the car body, on which the weight can be carried during the transfer from one set of trucks to the other. Eoad wheels may be substituted for the narrow-gauge trucks and the mount may then be hauled directly over a highway. 95. Am/rmmition supply system. — The ammunition supply system consists of a jib crane, which lifts the shells from the ammunition car, and the shot truck in which they are deposited. This runs on rails from the rear of the mount up to the breech. The loading angle is plus 10 degrees, and an automatic rammer of the flexible-link type operated by two handwheels pushes the shell into the gun. 96. Difficulties imvoVoed in the service. — The most serious difficul- ties are those encountered in transferring the mount from the stand- ard-gauge track to the firing position and the reverse. The gun can be operated at satisfactory speed when it is located in its firing position. 97. Merits. — The merits of this mount are doubtful. The schemes of attaching the narrow-gauge trucks permanently to the car and of lifting the standard-gauge axles out of the way, and the loading mechanism which permits the loading at considerable elevation are at least interesting. 274.4-MILLIMETER HOWITZER, MODEL 1870, 1881, AND 1870M. 98. This mount, Plate 55, which is a 1917 model, is another im- provisation from a seacoast gun and carriage. It embodies a com- bination of top-carriage and sliding recoil. The carriage was called " Affut G. P. A. 1883 " and is the same as that employed on the mount next described, No. 22. 99. Gwn. — Two types of guns are mounted on this materiel. The model 1870M is a howitzer of 15 calibers length. It is made up of a cast-iron body, with a liner inside at the breech end and two rows of steel hoops shrunk on the outside at the breech end. The breech mechanism is of the interrupted screw type, operated by a lever at- tached directly to the breech block, as in the 194.4 howitzer. No. 5. The model 1870, 1881 is a howitzer of 25 calibers length, but similar in other respects to the gun above. 100. Recoil mecTumism. — The top-carriage recoil on this mount is identical with that described in detail for the next mount. No. 22. The sliding recoil is similar to that on the large sliding mounts. For firing, a large part of the weight is transferred to the sleepers, which 64 rest on special rails and support the mount through jacks. The ver- tical recoil force is taken directly by the track, through the sleepers and special rails, and the horizontal force merely slides the mount along a short distance on the track. The movement of the mount back into battery is secured by hand cranks and gearing leading to the front axle, and by means of which the front wheels can be slowly rotated. The recoil of the top carriage on proof firing (gun model 1870, 1881) was 1,450 millimeters and that of the car on the track 220 millimeters at 30 degrees and 460 millimeters at 10 degrees elevation. 101. Elevatinff viechanism. — This is exactly the same as that of the next mount except that a slip friction device is incorporated with it. 102. Traversing meohoMism.. — No internal traversing mechanism is provided. It is necessary to operate the mount on a curved track, Plate 55 ^^mMmJm^M -31 10. a - LEFT SIDE EDEVATION 274.4-MM. HOWITZER, MODEL 1870-1881 AND 1870M ON RAILWAY MOUNT, MODEL 1917. and cranks and gearing leading to the front axle are provided for setting the mount exactly in azimuth and for returning it to its firing position after recoil. 103. RwWway car hody. — The railway car body includes the side rails of the racer of the original seacoast carriage as on the next mount described. In this case, however, all of the original transomp have been left in place, and a rectangular structural steel frame on which the axle boxes are mounted has been built around them. 104. Anchorage. — This mount was originally designed to operate with guys, like the 194.4 millimeter No. 6, but it was found that thesp were very heavy, and if they were dispensed with the mount would only slide back a short distance, and a mechanism could easily be provided for bringing it back to firing position. This mount re- quires, therefore, a track prepared with special bearing beams, on 65 which the sleepers can slide, similar to the track construction used with the larger sliding mounts later described. The sleepers, four in number, are located between the five axles, and the jacks which con- nect them to the mount are of the simple screw type, as used with the 194.4 millimeter mount No. 5. The upper ends of these jacks are castings which bolt directly onto the side rail castings of the old seacoast carriage. 105. Trucks. — This railway car is really one .5-axle truck. It is provided with brakes and semielliptical springs on each axle, but no equalizers. The wheels are solid and the entire truck con- struction is quite sturdy. 106. Arn/rmmition supply system. — The ammunition supply sys- tem is quite simple on this mount. An auxiliary tray, located at the rear end of the mount, and capable of being swung on a vertical axis into the end door of the ammunition car, serves to transfer the shells from the tongs in the ammunition car to one mounted on a small jib crane at the back of the mount. From this it is dropped into a stationary loading tray and pushed along a remov- able loading tray into the gun. An operating platform is provided which slides back and forth with the carriage in recoil, so that when the gun is back in battery there is a clear walk-way entirely to the breech. 274.4-MILLIMETER GUN, MODEL 1893. 107. This mount, Plates 56 and 57, is improvised from a front pintle type of tap-carriage recoil seacoast gun on two 4- wheel trucks. For reasons that will be mentioned later this mount did not see much service. The only opportunity that the writer had to inspect it was in the yards of the Chantier de la Loire at St. Nazaire, where they had probably been constructed and modified. 108. Gun. — The gim is of steel and is built up in the usual modern fashion. The breech mechanism is of the marine type, operated through gears, worms, etc., by the continuous rotation of a single handwheel. The firing mechanism is of the percussion type. 109. Recoil Tnechanhm. — The gun is swung by its trunnions on a top carriage, which in turn rests on rollers on an inclined track. The gun and top carriage recoil together on firing, rolling up these rails for a distance of 1.90 meters. The recoil is checked by a hy- draulic brake cylinder carried under the center transom of the car- riage. This cylinder is about 14 inches outside diameter and the 3-inch piston rod is attached to the forward transom connecting the carriage rails. Counterrecoil is by gravity, and buffers are pro- vided to stop it. For traveling, the top carriage is pushed back out of battery and secured in place. 66 110. Elevating mechanism. — The elevating mechanism consists of a train of spur gears, leading from a rack screwed to the gun to a handwheel which is provided with a clamp. There is no slip friction mechanism, and the gears are very light. The rack, for example, has only 1.75 inch face, with a tooth for each 2 inches along the cir- cumference. The ratio of the gearing is such as to give approxi- mately 1.8 degrees elevation of gun per turn of handwheel. Thirty- seven degrees elevation is provided for. 111. Traversing meohanism. — No internal traversing mechanism was provided. It is necessary to move the mount along a curved track to train the gun in azimuth. 112. Gun carriage. — The gun carriage, as above noted, is a stand- ard type of coast-defense mount of the front pintle type. The date 1878 was noted on one carriage. The top carriage consists of two Plate 56 274.4-MM. GUN, MODEL 1893, RAILWAY MOUNT. triangular side-frame castings, quite light and cut out so far as to form almost a truss, as shown in Plate 57. These side frames sup- port the trunnion bearings and elevating mechanism and are held together by two cast transoms, one fairly light at the center of the front of the side frames and the other very heavy along the bottom. This last supports the recoil cylinder and has the two counterrecoil buffers imbedded in it. The carriage rolls on eight wheels, each about 10 inches in diameter by 5.5 inches face, and is supported on the two rails of the old seacoast carriage, which have been made into the car body in this mount. 113. Railway car iody. — The lower portion of the old seacoast carriage consists of two heavy cast-iron beams or girders, about 30 inches in maximum depth, 5 inches in web thickness, and perhaps 8 inches in flange thickness. They are connected by a single cast 67 transom and three structural transoms, one at each end, carrying the center plate for the truck and two in the middle carrjdng the two central jack mechanisms. The cast transom was on the original carriage, but the others replace the original cast transoms which supported the front pintle and the rear traversing rollers. The center structural transom mounts two 25-inch wide AA'ooden sleepers each connected to the car through two screw jacks of the same type as used with the heavy sliding mounts. 114. Anchorage. — The anchorage arrangements with this mount are in general similar to those employed with the 194.4 and 240- millimeter howitzers previously described. Longitudinal sleepers are laid on the ties parallel to the rails and the wooden sleepers are jacked down onto them until part of the weight of the mount is sup- ported in this way. In front of the mount a rail clamp is secured Plate 57 Tbfol We'qnr of Material I49,ooo«' Weight Rsr Ft Run Over Bumpers Over Wheel Base Weight of Gun «|8So" Elevation tS*to37" Iroverse on Curved TraoK Weight of Pl-oJeotile sai.S* Weight of Change loa.B* Initiol Vslooity ziea Ft.flrSeo. Range MaxiMuN . zi,«7oyas. ELEVATION VIEW OF 274.4-MM. GUN, MODEL 1893, ON RAILWAY MOUNT ANCHORED FOR FIRING. to each rail and tension rods with turnbuckles extend from these to special fastenings on the front of the mount. The sleepers take the vertical load of fire and the guys and rail clamps the horizontal. 115. Trucks. — The trucks are four wheel, with structural side frames, outside journals, semielliptical springs without equalizers, and are equipped with hand brakes. Each truck is provided with a sleeper and two jacks similar to those described aboie. The truck construction is extremely light; the wheels are about 35 inches in diameter and have very small spokes. The journals .appear to be about 4 by 7 inches, and the whole construction resembles that used iinder the light French freight cars. 116. Ammunition supply system. — The ammunition supply system of this mount is rather complicated and interesting and would seem 452—22 6 to be the forerunner of the transbordeur system used with the large sliding type mounts. The entire rear operating platform rolls on rails located along the inside of the car body side frames, and by means of an operating handwheel and gearing can be moved back and forth a distance somewhat greater than the recoil of the gun. On this platform a special ammunition tray in four separate sections is mounted. At the rear is a hinged trough forming the first section. This can be swung down to a horizontal position to extend inside the ammunition car when the operating platform is pushed back to its rearmost position. The second section is a short piece of sta- tionary tray to which the first section is hinged. The third section, just forward, is another length of tray which can be moved vertically, by means of a handwheel and gearing, from the level of the first and second trays to that of the breech. The fourth section is another hinged trough at the level of the breech. When it is let down and the operating platform is run forward to its extreme position, this section projects inside the breech and the shell which was lowered by the ammunition car trolley onto the first section, when the plat- form was in the rear, can now be pushed along over the second onto the third section, the latter raised, and the shell again pushed onto the fourth section and into the gun. 117. Maintenance. — This mount gave so much trouble on the proof tests that it was never put into active use. In the first place, the weight, 70,000 kilograms, was too much for the trucks and they developed hot boxes, etc., to an impracticable extent. Second, the elevating gear was weak and had no slip friction, so that the whip of the gun broke the elevating pinion. Third, in order to lighten the mount, a nimiber of circular holes were cut in the side frames of the cast-iron car body girder (racer of the old sea-coast carriage). This so weakened the girder that it fractured from one of the holes out at a point midway between center pin and forward car-body jack (just under gun trunnion) . 274.4-MILLIMETER GUN, MODEL 1893, 1896, ON SLIDING MOUNT. 118. This is the first mount, Plate 58, of the famous series of rigid girder " Grlissement " type that owed its appearance to the desperate need of the French armies for heavy mobile artillery during the first few years of the war. The principle of dissipating the energy of recoil throug'h a series of friction beams was not new, for it had been employed on some of the improvised mounts, and the essentials of the principle had been employed even in our own Civil War. The combination of a heavy gun swung directly by its trunnions in bearings mounted on the side girders of the car with no recoil mechanism whatsoever was new and is a bit of daring design. It did 69 not appeal to Americaji designers at first and perhaps does not to many now. Under the conditions that prevailed for a long time in France — that is, a more or less fixed line — it was possible to construct great numbers of firing curves, and transportation facilities were IS lO 01 (0 J Ul Q O d \n Q HI z I u v\ relatively good. The mount worked most satisfactorily under these conditions, hence was a success. 119. Gun. — ^The gun is of steel with modified Manz breech mech- anism. The gun is provided with rigid trunnions of large diameter 70 on which it swings between the girders of the car body. Provision is made in the, trunnion supports for adjusting the center line of the trunnions. 120. Recoil mecJianism. — The recoil on this mount is of the sliding type. The full shock of recoil is received by the car body, which slides backward on the track about a meter. Counter-recoil, or the return of the gun to the firing position, is accomplished by means of a so-called translating mechanism — a handwheel and a system of, gearing on the truck by means of which the mount can be moved slowly along the track. For each mount two of these mechanisms are provided, one on each side of the front truck and each requires two men for operation. Details are shown on Plates 76-^77. In this particular mount the gears and sprockets are so proportioned that one turn of the car wheel is produced by 132 turns of the handwheel. The handwheel radius is 0.3 meter. A clutch is provided in the mechanism which is thrown out on firing; for traveling the chain from the axle to the jackshaft is also removed. The brakes used with this type of recoil are the sileepers on which the mount rests when firing. They will be more fully described under " Anchorage." 121. Elevatingr mechanism. — Elevation from to 40 degrees is provided, and the gun is provided with antifriction auxiliary trun- nions to lessen the effort of elevating. The gear train employed con- sists of a rack bolted to the gun, a pinion connected to a worm wheel through a slip-friction device, and a worm leading to the handwheel. One turn of the handwheel moves the gun through 0.65 degrees. 122. Traversing mechamism. — On all of the mounts of this type in use in the French Army no provision is made in the body of the car for traversing the gun. When it is desired to operate on a given target, a firing position is selected near an existing railway line. From this line a spur is constructed ending in a section of curved track of not less than 50 meters radius. This curve is so located that a tangent drawn at about its middle point passes through the target. The mount is placed on this curve for firing and may be traversed by moving it along the curve with the translating mechanism de- scribed under " E«coil mechanism." 123. Gun carriage, railway car lody. — In this design the gun car- riage and railway car body are one. It is composed of two struc- tural steel box girders fastened side by side by suitable transoms and decking. On each side girder, Plate 58, is a heavy cast-steel trunnion support. At both front and rear the car body rests on the trucks through a conical roller nest. King pins of special de- sign are employed. 124. Anclwrage. — The anchorage is of the track platform type, although really the track must be constructed with especially long 71 ties, closely spaced, before the real platform or bearing stringers are put in place. This platform construction is shown on Plate 59, and consists of eight I beams secured to the ties parallel to the rails. These beams are provided in sections of about 2 meters length, and when placed for action are bolted together into four parallel lengths, each consisting of two beams. Usually a length of about 40 meters is employed. They are then attached by means of screw spikes to the ties. A minimum of 30 minutes is required to connect or disconnect all of these beams, and even if the mount were forced to retreat and leave the firing beams behind the loss would not be serious. In transit all the firing beams for one mount are carried on one flat car. 125. The car body is provided with six wooden sleepers extending across under the central portion and attached to jackscrews and also with two similar longitudinal sleepers under the rear truck. These jacks are operated by the handles seen on the side of the car Plate 59 TRACK ARRANGEMENT FOR " GLISSBMENT " TYPE OF RAILWAY MOUNTS. and of the rear truck. By operating them the sleepers can be forced down hard on the firing beams,' or bearing stringers, so that a con- siderable portion (about one-half) of the weight of the mount is transferred from the trucks to the sleepers. When the piece is fired the friction between these sleepers and the bearing stringers reduces considerably the distance . through which the piece recoils. This sliding of the sleepers on the firing beams has given rise to the term " Glissement," which is ordinarily applied to all of these mounts. When properly anchored this sliding mount will ordi- narily not recoil a distance of more than 1 meter. The jacks are incorporated inside the box girders forming the side frames of the mount and each consists of a screw, operated through a worm wheel. The radius of the crank is 0.20 meter and one turn moves the sleep- ers about 0.3 centimeter. 126. Trucks. — The trucks contain five axles each, have a structural frame, 1-meter wheels, and semielliptic springs without equalizers. 72 The center pins are slightly inside the center of the trucks. It is understood that these last two points are due to improvizations which had to be made in the manufacture. As already noted, two trans- lating mechanisms are mounted on the front truck and four jack screws operating two longitudinal sleepers on the rear. 127. AmmMnition supply system. — Owing to the fact that the mount moves backward in firing, it is not possible to keep the ammu- nition car immediately behind it, and a shuttle car, called a trans- bordeur, shown at the left on Plate 58, is provided. It will be observed that at both ends are located hinges, so that the end sec- tions may be folded in transit. When in action the projectile is placed on a small rolling truck on the transbordeur by means of the overhead trolley in the ammunition car. The transbordeur is then moved up to the mount and the shot truck run forward to the extreme position, where the projectile is picked up by means of the tongs attached. to the overhead trolley on the rear end of the gun carriage. By means of this trolley it is taken forward and placed on the ammunition table, from which it is pushed into the gun by a mechanical rammer. The powder charge is di"nded into small sections (quarters) and is brought up by hand. The speed of firing with this mount is about one shot in from three to f our^ minutes, this much time being necessary for translating forward into firing position, re-laying, reloading, etc. 128. Maintenance. — The problem of maintenance of sliding-type mounts is a negligible one. The entire mount is of such sturdy con- struction that even with careless handling no damage is likely to be suffered. The officers who have commanded batteries of these mounts, as well as officers in charge of repair shops, report that the bulk of maintenance has been on firing mechanisms. 274.4-MILLIMETER GUN, MODEL 1893, 1896, WITH RECOIL ON MOUNT. 129. This mount. Plates 60-62, comprises a naval gun and cradle mounted on a special design of railway car. This mount is peculiar in two respects in that it is the only one in which provision is made for traversing the car body on the trucks, and likewise in that it is one of the two types of which armor is provided for the protection of the crew against aerial machine-gun fire, fragments of shells, etc» It is peculiar that the designers of this mount seemed to feel that the car-body traverse had not proved of any particular value, while the designers of similar mounts in the British Army felt that that feature had been of such value as to warrant incorporating it in all of their most recently designed mounts. 73 130. Gym. — The gun is the same as the one used on the mount previously described. It is adapted for use in a cradle instead of being provided with trunnions, however. 131. Recoil mechanism. — Cradle-sliding recoil is provided for on this mount. Because of the existence of the cradle the extent of the sliding of the entire mount is reduced to about 40 centimeters. Plate 60 ^^^^^^m. XH eo' 7" 16 - 274.4-MM. GUN, MODEL 1893, 1896, WITH CEADLE RECOIL SYSTEM AND MOUNT SLIDING. FIRING POSITION. 132. Elevating mechanism. — This elevating mechanism includes a screw instead of the usual rack. The extent of elevation is 25°. 133. Trawersing mechamism. — Car-body traverse is provided to the extent of 1 degree on each side of the center line. The mount must, therefore, ordinarily be fired from a curved epi. Exact train- ing can be secured by the car-body traverse, and, indeed, it is pos- sible to fire several shots before moving the mount back to the Plate 61 DUE TO CRADLE RECOIL SYSTEM THE " SLIDE " OF MOUNT IS SO REDUCED TO PERMIT COUPLING TO AMMUNITION CAR DURING ACTION. original position, its traverse being sufficient to take care of the change in direction. The traversing mechanism consists of a scre-^v arrangement on the rear truck, by means of which the rear end of the car body may be moved back and forth relative to the truck pivot- ing about the front truck. 134. Own carriage and railway car 'body. — The gun carriage and railway car body are combined in one. This consists of two steel girders between which the cradle swings. The rear of the mount 74 — 1 B c^ 1 i» Jl J|l u ■) to 1 inl hHIhI' £'''< m 5 flH ^K^^K ' i^^ ' a i i„ ■ wSmM^ ,^^ L '" ffiS wlfll^K '' '^'Z C O #1^ P^^n m^^^i WKm^--' *, ' "^^^B c3 r ^H VHB'^' ''-''' ' &; ,^£g- ^J Mrvfl Hn s^^^BI , rn i^ ■P^\ 'dH^^^^^^^I ^F^^^ ^^^^^^^^^^^^^■A ' Zfl «E%lb ^ ^^^H^^^^^^^^^l P' i O - o c H Z. 1 : rii H B ^j ■i^^^^^H^^^H| O < N'^ '^^^1 ' '.*' li !^^^^^^C^^^K' iMS O roue LEUSTHS OF Sr^/^OAXO JfAlL f Tuys/ifTrF/re j'/h ssct/oa/s of tocM Q fouK. r^yiT B£o ^.e. Tia/cies Jt^x-^ ^ o/^£ BioeK(nfaao) /i.x /(,.xzo. ^7J-^AV££S . EJIPLACKMENT DETAILS (SEE PL. S2), socket blocks under the jackscrews slide very ea^^ily on the greased steel plates mounted on the transverse timbers, and the force re- quired to traverse the mount is not very great. 99 179. After the firing platform has been carefully placed, from 30 to 60 minutes are required to place the mount and prepare it for action. The battery commander reports that more time is ordinarily required to remove the mount than to place it. This is to a large extent due to the fact that the center pin is likely to bind and be very difficult to remove. Ordinarily from the time of firing the last shot until the time of coupling the locomotive to the carriage there elapses a period of about one hour. At practice the best time that has ever been made in removing the mount was 25 minutes. This was under the most favorable conditions imaginable and with a thor- oughly trained crew. Such speed as this could not be made in the field. " 180. Trucks. — There is nothing unusual in the design of these trucks. Attention is called to the fact that the journals of these axles are on the inside of the wheels and as a consequence the journal bear- ings are most diflScult to replace. Attention is called to the fact, also, that the brake operates on only the center two pairs of wheels. 181. Anmmnition supply system. — ^A crane, Plate 81, is provided on the rear of the loading platform for raising the shell onto the tray and from there to the shot truck. A shot truck of the ordinary type is provided. It is understood that four men are ordinarily required to run the projectile. 182. 31 mntencmce. ^The battery commanders who have handled these guns as well as the officers in charge of the repair shops report that the bulk of the maintenance has been on the firing platforms. When the mount itself is handled with care there is little likelihood of any breakage or of the mount being damaged. There seems some possibility of breaking the pintle housing and the pintle itself being badlj- strained unless the mount is handled with care. So far this has not happened, however. Because of the long time required to remove the firing platform many of them have been damaged and some partly or wholly destroyed by enemy shell fire. 183. Difftculties invoVved in the service. — The most serious diffi- culty is the placing of the firing platform, requiring from two to five da3^s. A second serious difficulty is the removing of the firing platform, requiring a minimum of two days. Two other difficul- ties are the placing and removing of the mount. Considerable diffi- culty is sometimes experienced in so placing the mount that the pintle will drop into the socket in the heavy plate mounted on the firing platform. Considerable difficulty is likewise experienced in removing the mount, inasmuch as the pintle may bind severely in the socket. 452—22 8 100 O I o P a e o b D P s B Z a a o ■91 a 101 1 ^» ^p-s^^K W '2 ^ p o 15 P O O H O I1h H CJ l-H 00 g O tH z a Q o g a z a o 102 340-MILLIMETER GUN, MODEL 1912, ON SLIDING- TYPE MOUNT. 184. This is the same gun as the preceding, without any cradle or recoil mechanism, however, and mounted on a sliding-type car- Plate 87 340-MM. GUN, MODEL 1912, ON SLIDING TYPE MOUNT. riage, Plate 87, practically identical in design with mount No. 34, with the exception that it has four 8-wheel trucks instead ®f two .12-wheel. 370-MILLIMETER HOWITZER, ON BATIGNOLLES MOUNT. 185. This mount. Plates 88-94, is identical in design with the BatignoUes mount described under No. 27. The gun used on it was originally a 305 -millimeter naval gun, Model 1887, rebored and Plate 88 TOrj fe p^_°^" gr — L J.UAlfl L — L' A) J .L1 L!il 4H iJ^ L'.'.^.nj.'.Ml ^. — . UJJ jJJJ j'J.I Il L'l ??^ i\ 370-MM. HOWITZER, ON SLIDING MOUNT (BATIGNOLLES). shortened slightly. As a howitzer it has a range of only 16.5 kilometers, as against the 27 kilometers that it had as a 305-milli- meter gun. 103 Ed H 104 Plate 90 CRANE GEARING ON FIRING PLATFORM CAR. 105 I'LATE 01 APPROACH VIEW OF FIRING PLATFORM. I'LATE 92 CROSS TRACK VIEW OF FIRING PLATFORM. 106 M ^ Pmi'I j^^^^^H} ' ' isp^^^^i', 1 wMm'f-^ 1 Hb^UHkI^'' i^HI^I^^> N ^^^IHI^nif^ '' [^HHRP* H^H^^yK;;\> "^ l^^B^^BHB^ ■^H^^^^^HH^x < w^B^B^BBB^ 6 WK^B^^ ^^1^^^^ ffiP*"»^P^'' O ^^■■■^^^ j^ 1f^ 1 z ^^i^HH^^^^ 4^gfet'- fjk ,.A^ 1 '£ ^ ^^H^^^i '^ ^^Q^BI^^^^B[^^Hi^HHB^t^S» '^'fBfgfyiy" 1 ^ ^^vH^^^^H^^IHB' ' ' H '^ ^ 1 ^^HH^^nfe K 'ff> '^ ■H|p ' ^;|; 1 il^F^iSjB r ' ' 1 -*-^' " j^j||r^:i ' •■ ll 't' 2 ^Hk ' "P ^ =:^^K ' '-'% ^ "^^^^P* ' '"W ^ ¥|^Hk ' ^I < — '^Hfefi ^ ""R =^ k^I^^HHKk- ^s - Jo/KUBKBr" •■ ' S ^ a—^bh^^^^^^BSb 'Bp ^ ^hHHe.i'i ^5'' ^ HB^^^^^H^K. ^ SB* V mSKSB^^KI^^^'^**^mt ^ AmSumL^^V^B^' ~^SIU' -i^ M^^fv^'^^WB ^ *v !«."'•• Z: MMr^"|_ Ps*^^ ^tc - ' H^^^ fefc^ j^^^i^ j^jf Mfc^g P r-^i £||^^«^(HHjfiHMH|n^H|m '^ ^ ^^ 107 108 370-MILLIMETER HOWITZER, MODEL 1875, 1879. 186. This mount, Plate 95, is of the Schneider sliding type but represents the highest development of the type, at least in so far as its operation is concerned. None of them had been completed and ere in process of manufacture to be used with both 340 and 370 milli- meter howitzers in the shops at St. Nazaire as well as at Bordeaux 109 and the writer had the opportunity to examine one finished mount that had been tried out at the proving ground. 187. It seems that the designers had patterned this mount to a certain extent after the 520-millimeter mount which had been finished for nearly a year. It is provided with electric power for nearly every operation. The mount is translated electrically, the ammunition is hoisted, carried forward, and rammed electrically, and the gun is elevated and depressed by an electric motor. Observation of the mount during the final process of erection gives one the impression that he is seeing a traveling power station. There are control boxes in all conceivable places. And in the summer of 1919 after one of these mounts had been given its tryout at the proving ground it was the opinion of the chief designer that there was decidedly too much electrical equipment on it. Most of it went out of order with the fir- ing of the first few shots, presumably because the fastenings and the equipment itself were not sufficiently sturdy to stand the extreme acceleration of the mount on firing. 400-MILLIMETER HOWITZER. 188. This moimt, Plates 96-102a, is of the cradle-recoil, top-car- riage type and is in general similar to the 340-millimeter mount No. 35. The gun is a rebored 340-millimeter naval gun. Model 1887, and is provided with an interrupted screw breech mechanism of the system Farcot. 189. Uecoil mechanism. — As with the 340-millimeter gun on St. diamond mount this howitzer is carried in a cradle which in this ease, however, is supported on a top carriage which is rotatable with respect to the car body. The cradle is provided with two hydraulic cylinders at the bottom, and one pneumatic recuperator in the center at the top. The normal length of recoil is 0.875 meter or 34.4 inches. 190. Elevating mechanism.. — This mechanism comprises simply a train of spur gears, the rack being bolted to the right instead of the left side of the cradle as has been the case with so many of the guns already described. These gears, pinions, and shafts lead to the hand- wheel on the right-hand side of the top carriage, Plate 97. The ratio is 1.5 degrees of elevation per turn of the handwheel. 191. Traversing mechanism. — The traversing mechanism is prac- tically identical with that provided on the 305 and 370 millimeter BatignoUes mounts, Nos. 27 and 37. The gun carriage rotates about a pintle located at its forward end. To the rear of the carriage is attached a short rack into which a pinion meshes, the shaft of which is seen just in front of the ammunition table. This mechanism gives a traverse of 5 degrees on each side of the center. It will be noted 110 that the vertical shaft of the pinion which meshes with the tra- versing rack is not provided with a handle. A solid wrench is pro- vided by means of which the gun carriage may be traversed very slowly, the handle having a movement of 180 degrees without being removed and replaced. This is no disadvantage inasmuch as the traversing mechanism is provided almost solely for the correction of fire. 192. Gun carnage. — As is the case with the traversing mechanism, the construction of the gun carriage is likewise very similar to the Ill 112 construction of the carriages of the 305 and- 370 BatignoUes mounts. The carriage is composed of two heavy cast-steel sides which are joined by suitable transoms at the front and rear. At the front the gun carriage rests over a pintle built into the body of the railway car. 193. Baihom/ car hody. — The design of this car body is admirable in its simplicity, but no features are worthy of especial mention. As noted in Plate 97, it is composed of two side girders joined by seven transoms. On the rear is built a loading platform of con- siderably lighter construction than the car frame. 113 § H 1 H H < 1 O ^ ' -fl — JjM % • -===3^? 1:1^ = - ^t[ .1 M g •«jwi><;> s;\ s ^ II s 5 o tf o t fa O 1 1 i --'-^ H ^;>4^ J- — in [Jlq O b S «" < ^ « iJ / >-^. ft fe 1 •r f O K / 1— ( / 10 S / ji J .c J / 5 -« / ^ t^ M to g "&» / |S O / t G / V Si H •A« > 3 . 02 nt . /' 4 <9 P » «1 r ,T? \ J „0 ,6 " B 1^ \ I V ? s \ \ !3 M \ o o-* TWO. G.5 "S. «.6Z,5ANGLE, I4.«3 14. « 14. ^HOLE FOR RING. 16. X tS. REAR PLATFORM C S\«EB. /ADDITIONAL PARTS. H- SEVEN BEAMS IS. » 14. » 16 r- roUR LENGTHS.OF STANMRO fMIL J- TWENTY FIVE 5M. SECTIONS OF RAIL STRINGER-E. «>0 <^M. NARROW GAUGE TRACK, K- FOUR FLAT BE DN.G. TRUCKS 3.x 4. L-0NE8T0N ROLLING BRIDGE 6' ^<^^^?Ss^3^!ffll ^' M-TWO SOCKET BLOCKS- CARRleC ON .^::r/>^\?r4S»'/ REAR GUN CAR TRUCK: SEE PHOTQ SPADE SUPPORT- H. EMPLACB3MBNT DETAILS OF 400-MM. HOWITZER RAILWAY MOUNT. shown two views of this firing platform with the mount in firing- position. On Plates 100-102 are given sketches and photos of the individual parts composing this firing platform with indications of 452—22 9 116 ^^^^^^HB@>.^.. Z''-'^'-^;/'^ 117 their oohstruction. The platform complete weighs 29 tons, and from two to" five days are required for its installation. It is under- stood that an American battery succeeded in installing this platform in less than two days under very favorable conditions. These con- ditions were much more favorable than could be expected at the front. The rolling bridge shown on Plate 98 is used in the installa- tion of the firing platform. On Plate 100 is given a list of additional parts not shown on the sketches. These parts include four flat-bed narrow-gauge trucks, twenty-five 5 -meter sections of narrow-gauge track, a number of heavy beams, several sections of standard rail- way rail, and two socket blocks which can be seen carried on the Plate lOlA HEAVr TIMBERED UNITS OF FIRING PLATFORM. rear truck on Plate 97. In transit about five flat cars are required to carry this equipment, and before the platform can be installed considerable excavation is necessary. On Plates 101-lOlb are given photographs showing parts of this firing platform as found at the artillery park where the guns are located when not in action. Some idea of the magnitude of the job of handling such a platform can be gathered from the appearance of these parts. 195. It will be noted on Plate 96 that it is not necessary to re- move the trucks from this mount in firing, as is necessary with the 340-millimeter mount. The two struts observed at the rear of the car, communicate with the triangular timber spades. The socket 118 - blocks carried on the rear truck are placed over the timber spades and receive the ball ends of the struts. The forward end of the car is anchored rigidly to the forward platform. Under the center of the car it is necessary to dig a pit 5 feet deep to permit the gun to recoil when operated at its maximum elevation. 196. Although an excessive amount of time is required for the placing of the firing platform, the gun can be placed on the platform and prepared for action in a comparatively short time. Approxi- mately 30 minutes is sufficient time for this operation. There are no Plate lOlB BRIDGE SPAN READY FOE ERECTION. BRIDGE TRUCK ON NARROW GAUGE TRACK. difficulties in removing the car from the firing position in a very short time. The minimum time for removing the mount in case of emergency from the firing position is approximately 5 minutes. As much time is required to remove the firing platform as is required to remove the platform of the 340-millimeter mount. Two days is the average time. 197. /"ruc^s.— There is nothing unusual in the design of the truck. Attention is called to the fact that the journals of these axles are on the inside of these wheels and in consequence the journal bearings are most difficult to replace. It should be noted, likewise, that the front 119 truck contains six axles and the rear truck four. In each case the brakes operate on the center two pairs of wheels. 198. Amirmnitiov, supply system. — A pedestal crane is provided on the rear of the loading platform, Plate 96a, for transferring the Plate 102 FIRING PLATFORM NEARING COMPLETION. shells from the ground or ammunition car to the tray on the top of the ammunition table. In loading the gun is depressed 8 degrees and a tray of suitable length is placed between the breech and the front end of the inclined section of the tray on the ammunition table. The hinged tray is tipped forward and the projectile is forced down 120 the incline and rammed by four men. The powder is provided in quarter charges. 199. Maintenance. — All that has been said with reference to the maintenance of the 340-millimeter St. Chamond applies to this mount. The battery commanders report that practically all' of the maintenance to date has been on the timber-firing platform. Because of the long time required to remove the firing platform some have been seriously damaged by shell fire and some lost. It has been ar- gued that inasmuch as these platforms are made of timber that the loss is comparatively insignificant. It is true, however, that tim- bers of the sizes used in this platform are not by any means easy to PtATE 102A 400-MM. HOWITZER MOUNT, TRAVELING POSITION. secure. Beams 14 by 16 inches by 15 feet long are not easy to find even in ordinary times, and under present circumstances they are even more difficult to secure. It seems, therefore, that damage done to these firing platforms is well nigh as serious an injury as suffered by the mounts themselves. 520-MILLIMETER HOWITZER. 200. To the best of our knowledge this is the largest gun con- structed during the war or to date and fires the heaviest projectiles (3,014 pounds) and heaviest explosive charge (660 pounds) so far used. The mount represents a fourth distinct type in that it com- 121 s o O 122 bines the principles of cradle and sliding recoil. The force of re- coil, 17,860 tons-meters, is so great as to make it impossible to mount the gun directly on the side girders of the car body and operate at high elevations — ^that is, up to 65 degrees. No track construction would stand such forces ; hence the appearance of this fourth type. 201. A word about the history of the guns and mounts is of in- terest. At the beginning of the war the Germans sprung the sur- prise of the 420-millimeter mortars, which they used in quickly reducing the forts of Liege. There is evidence to indicate that some of these mortars were at one time mounted on raihvay car- riages. Those now in our possession are on field carriages. These mortars were, of course, the siirprise of the time' and were unques- tionably most • effective. They were used again in the reduction of Namur, but to the best of our knowledge not again during the entire war. French designers were soon set to work on the 520- Plate 103 RAILWAY MOUNT OF SLIDING TYPE MOUNTING 520-MM. HOWITZER WITH CRADLE RECOIL. howitzer, not particularly because there was any great need for them but to serve somewhat as a political gun. Although finished early in 1918, the guns were never used on the front. During the summer of 1918, while one of the mounts was being used to prove ammunition at the Quiberon proving ground, a shell burst prema- turely in the bore of the howitzer, completely destroying the gun and carriage. 202. Gun. — The gun enjoys the distinction of being one of the only three or four new large guns that were designed, constructed, and mounted on a railway carriage during the war. It is 16 calibers long and has 168 grooves twisting to the right at an angle of 7 degrees. The breech mechanism is of the Schneider automatic type, with air recuperator and electric firing mechanism. 203. Recoil mechamsm. — The gun is carried in a cradle, which is slung directly by its trunnions in bearings mounted on the side 123 girders of the car body. The cradle is provided with four hydraulic recoil cylinders and two pneumatic recuperators. The length of recoil in the cradle is 0.945 meter. In addition, the mount is of the sliding type and is provided with five sleepers under the car body and one under each span bolster, Plate 103. The length of sliding recoil is about 1 meter. The mount is returned to its firing position by an electric translating mechanism. 204. Elevating mechanism. — The elevating mechanism is provided for both hand and electric power operation. It comprises a rack bolted to the left side of the bottom of the cradle, Plate 105, and a train of spur gears leading to the hand-wheel just in front of the left trunnion bearing and to the motor mounted between the side girders forward of the gun. 206. Traversing mechanism. — The gun can be trained in azimuth only by moving the mount along a curved track. The translating or traversing is accomplished by two electric motors mounted in the outside trucks and connected to two axles each by chains. There is no provision for hand translating or traversing. 206. System of anchorage. — The mount is provided with seven sleepers or friction beams, five under the car body and one under each span bolster. These sleepers are forced down on the special firing beams by jackscrews exactly as in the 274, 305, 320, 340, and 370 millimeter sliding mounts. For details of the beams and jacks see Plate 119, Volume I. 207. TrucliS. — The trucks, Plate 105, comprise structural steel frames carrying four axles each. The axles of the outside trucks are equalized in pairs, while those of the inside trucks are equalized throughout. Even in this extremely heavy mount, 236 metric tons, the braking is done entirely by hand. Xo air brakes were observed on any French mount. 208. Ammunition supply system. — The ammunition supply system is not unlike that of the other sliding mounts. In this case, however, the transbordeur is driven by an electric motor and all operations of handling, lifting, and ramming the projectile are likewise by electric motor. The special joower plant seen at the end of the train in Plate 104, lower view, is kept about 100 meters from the mount when in action, and the current conducted to the mount and transbordeur by cables. 209. Merits. — This is an ^admirably designed piece of mechanism and is an example of the typical painstaking French workmanship. 210. Demerits. — Since the passing of heavy permanent fortifica- tions there would seem to be no need for so heavy a weapon as this. It seems a waste of money and the time of valuable manufacturing facilities. 124 125 BRITISH RAILWAY ARTILLERY. 9.2-INCH GUN, MARK XIII. 211. This mount, Plates 106-112, is of the top-carriage recoil and top-carriage traverse type. It comprises a Mark XIII gun mounted on, a Mark IV top-carriage and a Mark III railway car. Plate' 106 FRONT AND REAR VIEWS RIGHT SIDE OF BRITISH 9.2-INCH GUN ON ALL AROUND FIRE CARRIAGE. It must be considered an improvization since it is made up of an ex- isting coast mount and gun and a railway car designed to suit the peculiarities of the coast carriage. (126) 127 212. Gun. — The gun is of the wire-wound type, comprising two interior, or A tubes, around which the wire is wound, and a B tube and a jacket, which are shrunk on over the wire. The trunnion hoop with trunnions is shrunk on over the jacket. The breech mechanism is of the Welin screw type and breech is opened by a single movement of a lever swinging in a horizontal plane. The firing mechanism is of the percussion type. 213. Recoil medhanism. — This mount has the top-carriage type of recoil, Plate 108, with a combination of spring and gravity counterrecoil. It differs from most of those previously described in that no rollers are provided under the top carriage, the latter sliding on special bronze liners instead. The maximum recoil is from 34 to 36 inches. Plate 107 REAR VIEW LEFT SIDE ELEVATION. 214. Elevating mechanism. — The gun trunnions are supported on the top carriage on a special antifriction auxiliary bearing of the roller type. All of the elevating mechanism, Plate 109, is mounted directly on the top carriage and recoils with it. It consists of a rack attached to the gun, a pinion, a slip friction, a worm wheel and worm, leading through bevel gears to the handwheel. The ratio of the gearing is approximately there-fouths degree of eleva- tion of gun per turn of handwheel. A total elevation of 40 de- grees is allowed. Plate 108 is an illustration of an identical mount but carrying a Mark X gun, hence the elevation of only 30 degrees. 215. Traversing mechanism. — The rotating top carriage of this mount rests on a nest of 35 conical rollers and can be traversed 360 degrees, Plate 109. The lower roller path is provided with a tra- versing rack, and a pinion attached to the racer meshes with this and is operated through a worm and worm wheel, slip friction 128 129 130 Plate 110 device, tAvo sets of bevel gears, and one set of spur gears, by a hand- wheel located on the racer just forward of the elevating handwheel. 216. Gun carnage. — The recoiling top carriage, Plate 107, of the mount consists of two cast-steel slides connected by a box-shaped cast-steel transom. It rests on a subcarriage built up of two side girders of plate and angles, connected by transoms and resting on the upper roller path castings. The loading platform is attached to the back ot this rotating jjortion. 217. Railway cat tody. — The railwaj' car bodj'', Plate 106, is ofthe"flat"type^ constructed of struc- tural steel with plate girder side sills fit- ting down over the outside of the trucks, suitable transoms, etc. The car body is mounted on the trucks through hy- draulic jacks at the center pins, and it can be raised and lowered as a unit by them through a dis- tance of 16.75 inches. Four hinged struts, similar to those on the Schneider 200- millimeter howitzer, are attached to the side girders, Plates 109-110. 218. Sy stein of anchorage. — For firing, the mount is lowered until the side girders rest upon the ties, as shown in Plate 109, the hinged struts are swung out and braced in position, and special spades, shown in detail on Plate 110, are put under them. The writer was told by the battery commander in charge of a gun of .this model that these outriggers and spades were very satisfactory. On the mount observed in firing position on the British front two 1-inch cables or holdfasts, attached as shown in Plate 111. were used in addition to the out- PI.AN AND ELEVATION VIEWS OF OUTRIGGER FOE CAR JIABK III. 131 riggers. Deadmen for these cables were 16 by 16 inches by 12 feet, buried 6 feet under the surface of the ground. Instead of being low- ered directly on the ties, as shown in the plate, the mount observed was lowered onto a special platform similar to that used with the American 8-inch mount. 219. Trucks. — ^The trucks are six-wheel, with 5.5 by 10 inch inside journals, structural steel side frames, and semielliptical springs. 220. Armmmition supply system. — A special rack holding seven shells and the corresponding powder charges is located on the loading Plate 111 "Srll? &iix> I -ZifSSS ADDITIONAL ANCHORAGE USED ON 9.2-INCH GUN MOUNTS ON FIRING LINE AT FRONT. platform, Plate 112. A track, which can be swung out of the waj-, leads firom this to the breech of the gun, and a shot truck is arranged to run upon it. A jib crane is used to load the shell onto the truck. 221. Difficulties involved in the service. — It was understood from the battery commander handling these mounts that they had continual trouble with their system of anchorage. The outriggers do not hold, and the guys are not particularly desirable. On inquiry it was found that they have never used any rail clamps with this mount when firing parallel to the track. On suggesting the possibility of using rail clamps, they decided to make a trial of them. 452—22 ^10 132 133 9.2-INCH GUNS, MARKS X AND XIV. 222. The mounts used with these guns is identical with that just described. In fact, the illustrations used for the previous mount were taken from a handbook issued for these guns. The top car- riage is given as a Mark III instead of a Mark IV, as for the pre- vious mount. The only difference is in some slight details incident to the mounting of a gun of slightly different length. The description of the preceding mount applies equally to this, with the exception noted. 223. Elevating OTecAawm.— Elevation is limited to 30 degrees. BRITISH 9.2-INCH GUN, MARKS III TO Vic. 224. This is a general type of improvised mount, including seven different types of guns— Marks III, IV, IVa, VI Via, VIb, and Vic ; also two types of caxriages— Mark I and Mark II ; and three types of railway cars — Marks I, la, and lb. The Mark II mounting and the Mark la railway car, as shown on Plate 113, will be described. 225. Gum,. — Guns of alji the models above are of the built-up steel tube type and are provided with fixed trunnions. An interrupted screw breech mechanism fitted with a percussion firing mechanism is provided. 226. Recoil mechanism. — The carriage is improvised from an old naval mounting of the top-carriage recoil type. Two hydraulic cylinders are provided and 34 inches of recoil is allowed. On the original carriage counterrecoil was probably by gravity, but in order to give increased elevation the slides have been mounted at an angle of depression, so that the gun recoils down, and two counterrecoil springs, Plate 114:, are provided to return the gun carriage to battery. 227. Elevating mecJumism. — The elevating mechanism consists of a rack bolted to the gun, and a pinion, slip-friction device, worm wheel, and worm attached to and recoiling with the carriage, Plate 113. The worm shaft is arranged longitudinally, parallel to the direc- tion of recoil, and does not move, the worm simply sliding along it. The operating handwheel is at the rear end of this shaft. Elevation to 35 degrees is provided. 228. Traversing mechanism. — The gun carriage is of the front pintle type, and a traverse of 10 degrees on each side of the center line is allowed. The traversing mechanism consists of a screw extending across the car at the rear end of the carriage and provided with handles at each end. A nut on this screw is so attached to the carriage that the back end of the latter is carried from side to side with it. 229. Gun carriage. — The gun carriage is of the same type as the preceding, but it is mounted on a wedged-shaped piece of structural 134 .135 z p in o o o B M H Z o 136 steel, so that additional elevation is given the gun. No traversing rollers are provided. 230. Railway car hody. — The car body is of structural steel and is of the well type. It is provided with a warping winch, worked by hand, by means of which the mount can be pulled along the track. 231. System of anchorage. — This mount is provided with the roll- ing type of anchorage. To prepare for firing, a longitudinal stringer of teak wood is swung between the underside of the side sill of the car and the rail, leaving about half an inch of clearance. The brakes are set, the rails greased on the inside, and the warping rope is unfastened. On firing, the entire mount descends on the springs until the stringer and rail come into contact, and the whole mount rolls backward along the track. The warping rope is then con- nected, the brakes released, and the mount is pulled up into firing position again. 232. Ammimition supply system. — Two jib cranes, Plate 113, serve to pass the shells from the rear of the mount up to the loading tray at the breech. 12-INCH HOWITZER, MARKS I AND II. 233. This mount. Plates 115-116, is of the cradle recoil, top-car- riage traverse type, and obviously is an improvisation from an existing coast howitzer and carriage. The British Army used a great number of mounts of this general type during the years 1917 and 1918. Railway artillery was classed as army artillery in the British Army, and one found the various mounts more or less per- manently emplaced in their firing positions all along the line. The writer examined one of these mounts in the Ypres sector, which was then (March, 1918) under the charge of the Fourth Army. This mount was at the end of a spur track and in a location that required so much excavation that the top of the mount barely reached the level of the ground. This position was not more than 500 yards from the line, which at that time was on Zonnebeck Eidge. There was considerable evidence that there had been 'difficulty in holding the mount in position, for heavy timbers were all about the carriage, bracing it against the banks on either side, and heavy cable holdfasts in front. 234. Gvai. — Both howitzers are of the wire-wound type. Thej- comprise an inner tube and an outer jacket between which at the breech end the wire is wound. The breech mechanism is of the interrupted screw type operated, by the continuous turning of a handwheel. The firing mechanism is of the percussion type. These two howitzers are fitted on both sides with splines that check the 137 138 139 rotation of the gun in the cradle, the weight being carried by 10 narrow cylindrical bronze liners, Plate 116. 235. Recoil mecJumism. — The recoil mechanism, Plate 116, is of the hydro-pnemnatic and of the favorite British design in which the liquid of the pneumatic recuperator is constantly in contact with the air. The length of recoil is 32 inches. The single builer cylinder is mounted in the center at the bottom of the cradle and the two re- cuperator cylinders on either side of the center at the top, the air reservoir being mounted in the center between them. There is noth- ing unusual about the buffer nor in fact about the recuperator. The recuperator is an interesting design, however, and «f a type not used by ourselves except on the 8-inch field howitzers designed by the British and built by the Bethlehem Steel Co. in large numbers for us as well as for England. 236. Elevating rnechanism. — This elevating mechanism, Plate 115, is in duplicate, combining both a slow and rapid operation. It comprises a single screw attached to the bottom of the cradle and passing through a nut that can be connected by a clutch with either the slow or rapid gearing. The minimum elevation at which the howitzer can be operated is 40 degrees and the maximum is 65 de- grees. Operation at elevations of less than 40 degrees would bring the line of recoil sufficiently without the base of the top carriage as to turn it over. 237. Traversing mechanism. — The gun carriage, Plate 115, rests on a series of conical rollers which in turn rest on a circular track on the bed of the car. It is possible to traverse this carriage 360 degrees, but firing should take place only within 20 degrees on either side of the track center line. 238. Gim oarnage. — ^The gun carriage, Plate 115, is of the barbette type and comprises two structural-steel side frames mounted on a racer of ordinary design and connected with each other by a transom and the operating platform. The crane used in lifting the shells from the ground to the tray is mounted on this working platform, although it is not shown on the cut. 239. RaiMuay car iody. — The railway car body, Plate 115, is of the platform type and not materially different from that used with the Mark III and Mark V howitzers, Plates llY-120. A comparison with Plates 117-120 will show that there is no fundamental difference. 240. System of anchorage. — The mount of this type that was found in use on the British front was resting on a firing platform, very similar to that used with the American 8-inch car. Over the front and rear trucks are located screw jacks used in raising the car for placing or removing the platform. In addition to this platform the car was anchored forward by two 1-inch steel 140 cables attached to 16 by 16 inch by 12 foot beams buried 6 feet below the surface of the ground. For lateral bracing 12 by 12 inch timbers were placed between the side of the car about in line with the center of the tracks and an improvised timber platform in the back beside the car. The entire anchorage system seemed an un- satisfactory improvisation. 241. Ammunition supply system. — The scheme of transferring the projectile from the ground into the gun is the same on these two mounts, but unlike the scheme employed for the Mark V howitzer, Plate 117. This equipment comprises a crane located on the left side of the worlfing platform by which the projectile is trans- ferred to the tray carried on the arm attached to the left side frame of the top carriage. When the arm is swung to the right the lip of the tray enters the breech of the gun and the projectile is rammed by hand. 12-INCH HOWITZERS, MARKS III AND V. 242. The mounts for these two cannon are identical in design. They are shown on Plates 117-120, some of which are labeled for the one and some for the other. It will be seen from a comparison of Plates 117-120 with Plate 113 that there are many differences in the design of the various details of the top carriage, cradle, loading system, and elevating gear. Some of these differences will be dis- cussed in detail later. 243. Gun. — There are no essential differences between the design of the interior of these howitzers and the Marks I and II. The Marks I and II howitzers, however, were fitted with splines on either side and were carried in the usual type of cylindrical cradle while these pieces are provided with guide hoops, by which the gun is sup- ported on the top of an open or under type of cradle quite similar in design to that used with the 8-inch field howitzers. Thpre are no essential differences in the design of the details of the breech mechanism. 244. Recoil mechanism. — The cradle and recoil mechanism are shown best on Plate 117. The cradle is made up simply of plates and special angles and the design of the individual units of the recoil mechanism is not unlike that of the similar units of the Marks I and II mechanism. There are two hydraulic buffer cylinders and one pneumatic recuperator cylinder, in which the liquid is always in con- tact with the air. The pistons of all three cylinders are attached to the recoil lug at the rear. The maximum recoil is 62 inches with full charge and at an elevation of 45 degrees. 245. Elevating mechanism. — -The elevating mechanism, Plate 120, is not essentially unlike that of the previous mount. The nut through 141 142 143 which the elevating screw passes is mounted between the side frames of the top carriage and somewhat to the rear instead of outside and at the front, as on the Mark I mount. This mechanism is provided for both slow and rapid operation, as with the other, and the details of the design of this feature are the same. The elevating handwheel is mounted on the left side of the carriage. 246. Traversing mechanism. — See the same for the Mark I mount. 247. Gun carriage. — A comparison of Plates 115 and 120 shows a difference in the shape of the side frames of the top carriage and quite a difference in the working platforms. The racers, roller paths, and bases are quite similar. There is nothing sufficiently unusual in the design to merit detailed description. All that one can be interested in is to be seen from inspection of the plates. 248. Raihoay car iody. — The slight difference in design of this car body from the Mark I body is nonessential. The body is of struc- tural steel throughout. Jack screws are provided at either end for use in emplacing the mount. They will be mentioned in detail later. 249. System of anchorage. — The system of anchorage is not unlike that for the Mark I mount. Heavy beams are placed under the well section of the car body and holdfasts can be used in front if desired. On the other hand the mount can be permitted to slide to the rear on the beams and after raising the mount from the beams it is brought back to firing position by means of the warping winch installed in the forward vertical leg of the car body. Emplacing jack screws are incorporated oyer each truck, by means of which the car body can be raised from the truck to allow placing of the beams and likewise rais- ing of the car body to perjmt a return to firing position. It will be observed in the photographs, Plates 117-120, that the two screws over each truck are driven by ratchet levers which are connected with each other in parallelogram fashion and ropes are attached on either side so that crews of men on the two sides of the mount can exert sufficient force to turn the screws up or down as desired. 250. AmmAinition supply system,. — The projectiles are transferred from the ground to the tray by means of a demountable crane which can be attached to the rear of the working platform as shown on Plate 120. It can be seen on the side of the platform on Plate 118. The cable of this crane goes to a winch in the rear of the top carriage where it is operated by a handle that can be seen on Plate 120. This mount is provided -^ith a shot truck mounted on a special track. The truck is run forward from its permanent track over a hinged bridge onto special rails in the cradle until it bumps the breech of the gun. The projectile is rammed by hand. 144 145 Cl, 146 12-INCH GUN, MARK IX. 251. This is one of the three mounts developed for the British n nny during the war that may be considered really developments in- stead of improvisations. It embodies a high-powered gun, mounted on a carriage provided for at least a fair elevation, 35.5 degrees, and for rolling recoil which is generally considered an admirable de- velopment for the character of warfare that circumstances compelled both sides to wage. It is illustrated on Plate 121. 252. Gun. — The gun, Plate 122, is of the wire wound type, the wire in this case being wound from end to end between the second A tube and the jacket and B tube. The breech mechanism is of the Welin stepped thread type, operated by the continuous rotation of a single handle. The firing mechanism is arranged for either electric or percussion firing. 253. Recoil mecJianism. — This recoil mechanism comprises two hydraulic buffers and four spring recuperators. The design of the details of these separate mechanisms is not unusual, but the method of applying them to the gun and carriage is unique. The gun is sup- ported on a cast-steel slipper which slides on the rails of the cradle. The forward end of the cradle is built up to encircle the gun com- pletely. The side castings contain the trunnions. Three of the spring cylinder pistons are attached to the east yoke over the gun and the fourth to the front of the cradle below. The spring cylin- ders themselves are attached to the gun and recoil with it. The initial working load of each spring cylinder is 10,296 pounds and the maximum 38,000 pounds. The maximum length of recoil is 33 inches. 254. The hydraulic cylinders are attached to the cradle on either side of the gun and at the rear. The pistons are attached to the slipper and are in compression when the gun recoils, instead of in tension, as is the general rule. An automatic leakage pump is pro- vided in connection with these cylinders. The liquid used is a half- and-half mixture of glycerine and water. 255. In addition to the recoil mechanism just described the mount is permitted to roll back on the track on firing. The brakes are set hard and serve to check the recoil of the mount within a distance of about 40 feet. A special gasoline engine driven capstan is pro- vided on the front truck, Plate 123, to pull the mount back to its firing position. 256. Elevating mechanism. — The elevating mechanism comprises two racks fastened to the lower side of the cradle, engaged by two pinions mounted on the same shaft, a worm wheel mounted on this shaft, and a worm operated through bevel gears from two hand- wheels located on either side of the car body. The mechanism 147 a o H in a o M Q Z o o K S ci O Z o ^ 452—22 11 148 '?'~A — BMW"" O t- (I s=o ■ ONm^ K 2 o so «. U M ui « *. 1- 149 includes also the reduced trunnion lever-type of antifriction mecha- nism in connection with the main trimnions. This is the first use of Belleville sprigs that the writer has observed in connection with a British railway mount. The total elevation attainable is 35.5 degrees, and the ratio of the gearing is one turn of the handwheel to 0.376 degrees of elevation. 257. Traversing mechanism. — Strictly speaking, this is a rolling type of mount, and the desired traverse is secured by oj^erating it on a curved track. The mount is provided with car body traverse likewise to the extent of about 2 degrees — that is, 1 degree on either side of the center. The car body is rotated about the king pin of the rear truck by a traversing mechanism located on the front truck, Plate 121. This mechanism comprises suitable steel castings attached to the truck and car body, a set of six hardened steel rollers to reduce the friction of movement, and a traversing screw and nut. The screw is rotated by two handwheels through an epicyclic reducing gear. The ratio of the gearing is one turn of the handwheel for 17.45 !-:econds, or 0.00458 degrees of movement of the gun in azimuth. 258. Gu7i carriage. — The gun carriage is incorporated in the rail- way car body and is described briefly in the following paragraph : 259. Railway car tody. — The railway car body, Plate 121, is made up of two structural-steel side girders joined by a series of structural-steel and cast-steel transoms. The girders are of rjuite peculiar shape and require an snusual amount of tedious and diffi- cult bending of the chord angles. A loading platform of somewhat lighter construction is built on at the rear. ' 260. Syf^tem. of anchorage. — This mount being of the rolling re- coil variety requires no platform. or emplacing equipment. It is necessary to operate it on a curve to secure any great degree of traverse, but if the target is small enough and sufficiently accurately located the mount may be used on a section of straight track, es- pecially prepared for the occasion, and the car-body traverse used for correction of fire. The curved or straight track so used should he made up of extra-heavy rails, long heavy ties, and a heavy bed of good ballast. Unless the track is thus well constructed it is likely to be pounded down to the extent of as much as from one-quarter to one-half inch per shot. The brakes are set hard for firing and the mount rolls back a distance of about 40 feet. It will be recalled here that all rolling mounts so far constructed have in addition a hy- draulic recoil mechanism. This reduces materially the intensity of the shock transmitted to the track at any one instant and not onVy reduces the stressing of the carriage but the track as well. It is neces- sary to tamp up such a track after some use, for no matter how well constructed it will sink to a certain extent. 150 151 261. Ti-ucks. — The mount is supported on four trucks, Plate 121, two front having four axles each and two rear having three axles each. The wheels are 45 inches in diameter, and the truck bodies are entirely of structural steel. The journals are of the objection- able inside variety. One brake shoe is provided on each wheel and the braking is done by hand only. 262. Ammunition supply system- — A shot truck built up of steel plates and angles, Plate 121, running on rails from the rear of the loading platform to the breech of the gun, is provided to transport the projectiles from the ammunition car to the gun. The truck is stopped and locked in its rear and forward positions by a spring bolt entering into sockets on the floor. This bolt is released by a foot pedal. The truck receives its projectiles from the overhanging trol- le}' of the ammunition car; is run forward by two men, and locked in position with the forward end of the tray projecting inside the gun sufficiently to protect the threads. The projectile is held on the tray by a stop, which is drawn out of the way by a cam on the floor just as the lip of the tray enters the gun. The projectile is rammed by hand. A socket is provided in the floor several feet from the rear of the- working platform where the shot truck may be locked in transit. 263. The ammunition car is of special design and carries 96 pro- jectiles, arranged in 12 compartments, 6 on either side. Each com- partment carries 12 projectiles, arranged in 4 tiers of 3 each; each tier is separated from the next by two wood spacers. The car is so designed that the ammunition can be supplied from either end. The car carrying the powder is coupled between the locomotive and the shell car and the bags of powder carried through by hand. A locomotive is required constantly while in action to run the shell and powder cars up to the mount and back again. The acceleration of the mount is too great to permit the men remaining on it when it is fired or to permit coupling the shell and powder cars to it. 12-INCH GUN (OLDER MODEL). 264. This mount is the first design made up for a 12-inch gun and served most valuable purposes in the Somme offensive of 1917 and in the general offensive of 1918. The writer observed one of these mounts near the one-time village of Dickebush, in Belgium, in March', 1918. It had been emplaced in that location for some time, being operated on a ' curved track, and was camouflaged as a huge manure pile by raffia nets spread out from the mount in all directions. Some of the very vigorous opinions of the officers in charge are now recalled with reference to the relative merits of spring and pneumatic recuperators. These men had had a good 152 long taste of the mud of Flanders and were in consequence de- cidedly opposed to any refinement or delicacy in the mechanisms that they were called upon to handle. This mount had spring recuperators. 265. Gun. — The gun is practically identical in design with that previously described. Its mounting in the cradle is different, hence minor difference in the exterior details. It is 40 calibers in length, is rifled at a uniform pitch to the right of one turn in 30 calibers, has 48 grooves, and operates at a service pressure of 36,000 pounds. The breech mechanism is of the interrupted-screw type, and is fitted with a percussion firing mechanism. The extreme range is 28,000 yards with an 850-pound projectile. 266. Recoil mechanism. — To the cradle are attached two hydraulic cylinders, about 15 inches in diameter, and two spring recuperator cylinders of about the same diameter. All of the cylinders are on the bottom of the cradle. It was somewhat of a surprise not only to fiiid a mount of this size provided with these spring recuperators but likewise to find that the battery and group commanders and chief inspector of ordnance materiel of the army in which this mount was observed very decidedly preferred spring recuperators to pneumatic. It seems to have been their experience that, at least in the mud of Flanders, spring recuperators are easier to maintain than pneumatic. They reported that they had not experienced any serious difficulties in the use of this recoil mechanism. 267. Elevating mechanism,. — To the bottom of the cradle is bolted an elevating arc of considerable length. This is the only mount of this size observed on which the elevating arc is attached at only one end. It projects down a considerable distance into the body of the car, where it meshes with a pinion on the horizontal shaft. It is possible to elevate the gun to about 30 degrees. 268. Traversing mechatrdsm. — The traversing mechanism, Plate 124, of this mount is the one feature worthy of especial comment. It will be remembered that in the case of the 340-millimeter St. Cha- mond mount, when the mount is ready for action it rotates on a pivot in the center of the car, the trucks being removed and the front and rear ends sliding on steel plates. In the British mount the whole car body is made to rotate about the king-pin of the front truck as an axis. The traversing mechanism, Plate 124, is located on the rear truck. The center plate, which acts as a pintle or king-pin, is riveted onto the truck. On the top of this is a free block. A, capable of rota- tion about a vertical axis. In the top of this block is a groove in which are placed five steel rollers, B, and on the rear of the block is a rack, C, 24 inches long. To the body of the car is riveted another plate, D, which fits over the free block and rests on the rollers. To the rear of the car body are attached two bearings, E, carrying a 153 154 vertical shaft, F, on the bottom of which is the pinion, G, which meshes with the traversing rack. At the top of this shaft is another pinion, H, meshing with the pinion on the shaft, I, leading to the side of the car. 269. A special handwheel, J, 36 inches in diameter and provided with differential gears, K3-K4, is placed on the end of shaft in prepar- ing the mount for action. On shaft, I, are noted two gears, one of Avhich, Ki, is fixed to the side of the car, and the other, K2, is keyed to the shaft. On the handwheel are the other two gears, K3 and K4, both of which are free on their shafts but which are free to move with respect to each other only a short distance ; that is, a pin on the side of the K3 fits into a groove in the inside of K4. These differential gears give a very slow but sufficiently rapid movement to shaft, I. One turn of the handwheel traverses the mount two minutes. The rack provided on the free block is of sufficient length to permit the mount to be traversed 1 degree on each side of center. All of the parts of this traversing mechanism were examined carefully for signs of wear, and none were discovered except on the differential gears, which had been worn considerably. On the vertical shaft, F, a second bevel gear, L, will be observed meshing with the gear on the small horizontal shaft, M, leading to the side of the car. On the end of the horizontal shaft is a pointer, and on the side of the car is a dial graduated in minutes. The approximate degree of traverse of the mount can be gauged from this dial. 270. It is necessary to fire this mount from a curved track to se- cure the necessary traverse to cover a target. The battery com- manders report that when operating the mount on the curve the two degrees of traverse provided for in the mount have always been suf- , ficient for their needs. At the maximum range of the gun the trav- erse provided in the car covers an arc of about 1,000 yards. 271. Gwn carriage. — No gun or top carriage is provided. The cradle is mounted directly on the side girders of the car body. 272. Railway car tody. — There are no features of this car body that are of unusual design. The car body is composed of two struc- tural steel side girders joined by a series of structural steel transoms. On the top of the car at the rear is built a loading platform some- what similar to that provided for both the 340 and 400 millimeter St. Chamond mounts. 273. System of anchorage. — The scheme of anchorage of this mount is the simplest employed with any mounts in the French and British Armies. As noted before, the mount is provided with an internal traverse of only 2 degrees. It is necessary hence to fire from a curved track as with all Schneider sliding mounts. It is significant, how- ever, that no cross beams or sleepers are built into the body of the car as is true with the sliding mounts. In action the mount is moved 155 to the approximate firing position on the curved track by means of a locomotive and the gun accurately laid on the target by the use of the internal traversing mechanism. Before firing the brakes are drawn tight on both front and rear trucks and constitute the only means of absorbing the energy of recoil. On firing the mount runs back on the rails a distance of from 3 to 4 yards. It is returned to its firing position between each shot by means of the locomotive which is kept connected to the ammunition car a short distance away on the curve. No signs of injury could be discovered on the rear trucks as a result of permitting the full shock of recoil to come on the pintle and axles. The battery commanders and inspectors reported that they had never experienced any difficulty from excessive wear on the trucks or from breakage as the result of this scheme of anchorage. It was quite evident that the mount examined at Dickebush had seen considerable use and it was in most excellent shape. At the time that it was observed the mount was located on the curve from which it had been firing for some time. There was no indication from the condition of the track, which had been laid on about 8 inches of ballast on rather soft soil, that this scheme of anchorage was not satisfactory. 274. Trucks. — No features of these tnucks are worthy of especial mention except possibly the connection already described which the rear truck has with the traversing mechanism. The front of the mount is supported on one 3-axle and one 4-axle truck. The rear is supported on a single 4-axle truck. The truck bodies are of struc- turar steel and the axles have outside journals, are not equalized, and support the frames on helical springs. 275. Ammuwmtion supply system. — On the rear of the loading plat- form a stand is built, on the top of which is a track capable of motion parallel to the length of the car to the extent of a yard or so. On the top of this track is a short truck, on which the projectile is placed from the ammunition car. In loading the gun is placed at zero ele- vation and the track run forward until it strikes the breech of the gun. The small tray carrying the projectile is then run forward and the projectile rammed by four men. The ammunition car in- spected at Dickebush is identical in design with that described for the previous mount. 14-INCH GUN, MARK III. 276. This mount, Plate 125. marks the limit of development in the British Army during the World War, at least so far as construc- tion is concerned, if not in design also. It was examined by the writer in May, 1918, at Sandwich, England, where it was awaiting transportation by ferry to France. It embodies several unique fea- 156 tures, namely, the use of balancing cylinders to permit of mounting the breech of the gun closer to the cradle trunnions and the use of separate and direct connected gas engines for elevating the gun, driving an air -compressor, and driving the warping winch. These will be described in detail. 277. Gun. — The gun is a 45-caliber wire-wound gun, comprising two A tubes, the wire wrapping, a B tube, a jacket, a breech bushing, and a breech ring. It is provided with a breech mechanism of the interrupted screw type, operated by the continuous motion of a single handwheel. The firing mechanism is of the percussion type. The gun weighs 83 tons, and is rifled with 84 grooves at a uniform twist to the right of one turn in 28 calibers. The maximum range at 40 degrees elevation is 33,000 yards. 278. Recoil mechanism. — The gun is supported on a heavy steel casting called a slipper, which slides on the body of the cradle in recoil. To this casting are attached the pistons of the recoil and recuperator cylinders. The gun recoils a distance of 36 inches under full charge, and when elevated to 40 degrees it just clears the track at the end of the recoil. It can be seen from Plate 185 that the center of gravity of the gun is considerably forward from the center line of the trunnions. The gun has been so placed in order that it might be elevated to as much as 40 degrees and still have it clear the track at the end of its recoil. 279. The recoil mechanism comprises two hydraulic cylinders and one pneumatic recuperator. A recoil valve key in the wall of the cylinder regulates the rate of flow of the liquid past the piston. Only one such key is used. It can, of course, be compared with the throt- tling bars used on many American recoil mechanisms, but its opera- tion is somewhat different. The valve which is operated by this key is installed in the piston head. There is no buffer on this cylin- der such as is ordinarily found on cylinders used on American car- riages. On Plate 125, just over the forward truck, will be noticed an air compressor, which is used in charging the various tanks, one series of which will be noted over the rear truck and another series in the body of the carriage just behind the last wheel of the front truck. From these tanks air is supplied both to the pneumatic re- cuperator and to the balancing cylinder. The air compressor just noted is driven by a 15-horsepower gas engine. 280. Elevating mechanism: — The elevating mechanism comprises two screws approximately 5 inches in diameter, both being driven by a common shaft from a 15-horsepower gas engine located in the body of the carriage just above the rear wheel of the front truck. The shaft running from the engine is connected with the two shafts and drives the screws through the clutch, operated 357 from the outside of the ^ carriage on the left side. ^ This is a friction clutch ^ and permits of quite rapid elevation and de- pression. On each screw is a crosshead which is connected by two links to the cradle at the bot- tom and rear. In con- nection with this elevat- ing mechanism a bal- ancing cylinder is used to overcome the very considerable muzzle pre- ponderance resulting from mounting the gun with the center of grav- ity forward of the trun- nion axis. This balanc- ing cylinder is approxi- mately 12 inches in di- ameter and 9 feet long. To the piston project- ing from its forward end is attached a cross- head which is connected by two links to the cradle at the rear. In this cylinder an air pres- sure of approximately 1,100 pounds per square inch is maintained, and the effort on the screws required to elevate the gun is reduced to the ca- pacity of the 15-horse- power engine or to the capacity of four men operating a slower gear by means of handles. This system of balanc- ing can not be con- sidered perfect, and there are many places in the 40 degrees ele- vation over which the engine has difficulty in moving the gun. 158 There is little choice, however; in the mechanism that may be used in balancing a gun, of this length when it is mounted on a cradle permitting any considerable recoil, and the whole is mounted on a car- riage which is operated without the.use of the firing platform. If the carriage were of the type that is permanently fixed in any one posi- tion and a pit could be dug under the center into which the gun might recoil, it would, of course, be possible to balance the gun more per- fectly and extra balancing devices other than counterweights on the breach would be unnecessary. This balancing device is the price that is paid for a carriage which can be fired without any track preparation. 281. Traversing mecTuinism: — It is customary to operate this mount on a curved track where any desired degree of traverse may be secured. For adjustment of fire a traversing mechanism is provided on both the front and rear trucks, which permits of the move- ment of the entire carriage about an imaginary vertical axis through the center through a total of 4 degrees. The rack is attached to the body of the carriage. As the top carriage is moved to the right or the left it rolls on six rollers. This traversing mechanism hence is composed of a cast-steel housing carrying the six rollers, the two conical rings above, between which are the conical rollers, the rack, pinion, worm wheel, and jthe worm on the right of the truck. The spherical-shaped castings between the bolster and the truck are not unusual and are not a part of the traversing mechanism. The trav- ersing mechanism is operated by hand and, as noted above, the same mechanism is provided on both front and rear trucks. 282. Gun carnage. — There is no gun carriage provided with this mount, the gun being carried, as noted before, in a cradle which is suspended directly on the side girders of the car. Any traverse must be secured through a movement of the entire car body. 283. Gar hody. — The car body, Plate 125, is made of structural steel, being composed of two main side girders, each containing two webs, these main girders being connected by suitable transoms at the front, rear, and bottom, and just back of the gun. The portion of the car body forward of the trunnions houses a considerable amount of machinery : Four air tanks, the gas engine, which drives the elevat- ing gear, the elevating gear, the balancing mechanism, and the air compressor. The winch which is used in returning the carriage to its firing position is mounted forward of the center bearing of the front bolster. 284. System af anchorage. — This mount is one of the few at pres- ent in use in any of the armies which is fired without any trapk preparation whatever. In firing it is the custom merely to set the brakes, thereby taking up in friction as much of the energy of recoil as possible. The carriage runs back on the rails a distance of from 159 30 to 40 feet. It is returned to its firing position by means of the winch, Plate 125, carried on the forward end of the carriage, a cable being attached to the rail some distance in advance of the firing position. The firing curves inspected by the writer were somewhat heavier than those ordinarily used with other types of artillery. Inasmuch as the mount is operated on a curved track, there is a tendency, of course, to displace the track laterally, since there is a very considerable component parallel to the ground and normal to the track. 285. Trucks. — It can be readily understood that the trucks for a mount of this type, from which the gun is fired without any track preparation and in which it is necessary to communicate all the stresses of firing into the track through the trucks, it is essential to provide truck frames, axles, and wheels of extremely heavy con- struction. The springs are unusually heavy in order that they may withstand the shock of firing, and it will be observed in Plate 125 that the springs are equalized throughout on each truck in order that the stresses brought on each may be uniform. In addi- tion to the leaf springs carried over the journal boxes of each axle, helical springs are used on the vertical bars connecting the springs with the equalizing levers. Whether these helical springs are required in addition to the ordinary springs because of the type of the carriage it is not known, since full information on the develop- ment of the mount is not available. 286. Ammunition supply system. — The ammunition car with this rmount is an all-steel car, having bins on each side in which are carried 96 projectiles. To the roof of the car on each side is at- tached a track carrying a trolley by which the projectiles are car- ried from any part of the car through the end doors where the tracks meet. The ammunition car is always attached to the locomo- tive, and in loading the car is run forward to the mount. When the trolley is at the end of the track of the ammunition car the pro- jectile may be placed on the shell tray on the track. This track moves on three sets of rollers. As soon as the projectile is placed on the shell tray the track is moved forward until it touches the breech of the gun and the shell tray is run forward by hand, acquiring sufficient momentum to launch the projectile into the powder chamber from which it is rammed by hand. On Plate 125 also will be noted two winches which may be used in picking up projectiles either from the ground on the side or rear of the car or from other cars on an adjoining track, or at the rear on the same track. 287. 3Iaintenance. — Those who have operated this mount as well as the 12-inch mount of a similar design report that they have com- paratively few difficulties. Difficulties are, of course, to be expected 160 with the gas engines, some difficulty with the air compressor, and likewise some difficulty with the balancing cylinder. The recoil and recuperator cylinders require only the attention of the average mechanism of this type. No difficulties have been reported on the trucks from unusual stresses, although one would expect that broken bearings or bent journals might be the result of long-continued firing. 288. Difioulties imvolved in the service. — No especial difficulties have been reported by those who have operated this type of mount. As noted before, the foundation of the track must be very heavy. The, elevating mechanism does not operate smoothly and the engine that was first mounted in the carriage was not of sufficient strength. An engine of double the original capacity is now in use and to date is operating successfully. There are several points in the 40 degrees of elevation over which the gun does not move smoothly. As noted before, however, this type of balancing mechanism is probably one of the best that can be used and is the price that one pays for a carriage which is to be operated without any track preparation. 289. Merits. — The ammunition car, loading mechanism, and trav- ersing mechanism are all of excellent design. The loading mecha- nism throughout is simple, easily niaintained, and easily operated. The ammunition car is simple, sturdy, and efficient. The travers- ing mechanism gives a degree of traverse ample for all ordinary ])urposes and at the maximum range of the gun at 40 degrees ele- ^-ation, which is 33,000 yards, covers an arc of about 500 yards. Tha general design of the mount resulting in an elimination of the necessity for a firing position, may likewise be considered a merit inasmuch as no firing platforms and nothing unusual in the way of track preparation are required. The mount itself with its ammuni- tion cars and locomotive constitute the entire equipment required and it is ready for action always in a minimum of time. In com- paring this mount with a mount of the Schneider sliding type for a gun of the same caliber with which it would be necessary to place on the track a very simple type of firing platform composed of H sections, it is realized, of course, that this mount has the slight ad- vantage of requiring no platform at all. It should be remembered, liowever, that the Schneider type of mount does not require 'the manufacturing facilities required on the Armstrong mount for the manufacture of the cradle, recoil mechanisms, balancing cylinder, and air compressor. 290. Demerits. — There is no special featjire which may be consid- ered a demerit, although the balancing mechanism is not perfect. As just noted above, there is a question as to whether one is warranted in using the manufacturing facilities required for producing cradles, cvlinders, balancing mechanisms, etc., for a mount of this type for 161 field service, when the gun mounted on a Schneider sliding type of carriage can be operated just as rapidly, and the sliding type of carriage requires much fewer facilities for its construction. The controlling factor in the speed in which the mount may be served is the time required for loading the gun. In either this type of mount or the sliding type of mount it is possible to return the carriage to the firing position and lay it accurately in less time than it is pos- sible to load the gun. ITALIAN AND AMERICAN RAILWAY ARTILLERY. ITALIAN 381-MILLIMETER GUN. 291. This mount, Plates 126-127, is a combination of the cradle and sliding recoils, embodying likewise limited car-body traverse and semi-automatic elevation and depression. To the best of our knowledge it is the only railway-mount construction for the use of the Italian Armies and was made by the Ansaldo Co. In certain Plate 126 ITALIAN 381-MM. GUN RAILWAY MOUNT. respects it must be considered crude, in that it does not indicate the familiarity with the more recent developments in the design of rail- way artillery shown on certain French and American mounts. It must be remembered, however, that there was little occasion for the use of such artillery in the Italian Army and hence little to be gained by devoting meager design and manufacturing resources to its development. 292. Ghin. — The gun is a built-up piece of 40-calibe length and fitted with an interrupted screw-breech mechanism of the Welin type, Plate 132. The firing mechanism apparently permits of the use of electric jDrimers only. The breech of the gun is provided with a heavy counterweight, to which the various recoil and recupera- tor pistons are attached. Apparently the designers were not able to provide space for sufficient counterweight to allow of a very satis- factory elevation. 293. Recoil meehcmism. — The gun is mounted in the ordinary type of cradle provided with four hydraulic buffers and two pneu- 162 matic recuperators. The length , of recoil at maximum elevation is 48 inches. It will be observed that the gun is of such length that even after it is heavily counterweighted it is possible to secure an elevation of only 25 degrees. Under each trvinnion there is pro- vided an antifriction device, which, in effect, is the same as the antifriction device used on most of the Schneider-type mounts. The recuperators are of the same design in essential details as those used on British 8-inch field howitzers. The liquid is in constant contact with the air and on recoil is forced up through the con- necting tube into the air reservoir. The recoil buffers are of interest- ing design, containing a somewhat original use of a single throttling bar of varying section attached to the front end of the cylinder and sliding within the hollow recoil piston rod. The liquid passes through a series of ports in the rear end of the head and then out around the throttling rod. 294. Elevating mechanisTm. — On Plate 127 is shown the elevating rnechanism, which is composed of the main screw connected to the bottom and rear of the cradle, the spur gear, pinions, shaft, clutch, chains, and handwheels. Provision is made for unclutching the shaft, thereby releasing the two pinions ahd permitting the muzzle pre- ponderance of the gun to depress it to the loading position. It will be noted that the screw has sufficient pitch to turn the spur gear slowly and that on the end of the screw is a heavy nut with a washer, which provides a stop against the heavy block through which the screw passes. The depression is thus obtained simply by pressing the clutch treadle with the foot, whereupon the gun slowly drops to the loading position. The steel block carrying the spur gear is sus- pended by means of trunnions between the structural-steel side girders shown on Plate 127, lower view. 295. Traversing mechanism. — Inasmuch as the cradle carrying the gun is suspended directly on the side girders of the carriage it is, of course, necessary to operate the carriage on a curved track to secure any considerable degree of traverse. For finer adjustment, however, a traversing mechanism is prdvided over the rear truck. It will be noted in Plate 127 that this traversing mechanism over the rear truck consists of two handwheels communicating bv means of chains to sprockets on a hea^^y screw provided in the top carriage. This screw passes through the lug on the traversing beam or bolster. It will be noted that the top carriage is supported on the top of the tra- versing beam on 12 rollers aiid that the traversing beam is supported on the top of the truck by means of 11 conical rollers on each side. With this traversing mechanism it is possible to secure a traverse of a total of 2 degrees, 1 degree on each side of the center. 163 452—22 12 164 296. Gu7i carriage. — There is no separate top or gun carriage, the gun being supported directly in a cradle which is carried on the side girders of the car. 297. Railway car iody. — The railway car body is composed of two built-up side girders, composed of two webs each and of a profile not by any means easy to manufacture. It will be noted that the angles of the lower cord have some particularly difficult bends in them. Other than this slight difference in shape, the car body is not materially different from that used on the well-known Schneider type of carriage. On Plate 127 it will be noted that on the top cord recesses are provided for the trunnion bearings. This has resulted in a very difficult construction at this point. , 298. System of anchorage. — ^In plate 127 it will be seen that this carriage is provided with six sliding beams of the type usually found on Schneider mounts. The jacks provided with these beams are not Plate 128 j p„-^ 5 i s ^n^ ^ " JI -*■""" '~^"°~ mam TRANSLATING MOUNT WITH HAND WINCH AND CABLE. unusual in design, being composed simply of a screw and two bevel gears, the whole operated by a handwheel and lever. The method of operating the mount, however, is unusual in that the Italians are in the habit of placing down on the ties stringers of wood instead of steel, thereby securing a friction of wood on wood. The bottom of the jacking beams are not shod with iron and it is assumed that they would wear quite rapidly. It is necessary, of course, to raise the jacks between each shot, and the carriage is returned to its firing position by means of the translating mechanism located on the front truck. This hand mechanism operates the capstans shown. Plate 128, about either of which is wound a cable attached to the track in front. It is possible to return the mount to its firing posi- tion in less time than is required to load the gun. The final adjust- ment in laying the piece is, of course, obtained through the traversing mechanism explained above. On firing, the mount recoils on the track a distance of about 1 meter. 165 299. Trucks— In Plate 127 it will be observed that both the front and rear trucks are made up of structural-steel frames and that the axles have outside journals. At the front a structural-steel bolster is provided connecting the two 4-axle trucks. Hand brakes are provided on both the front and rear. In front the axles are equalized in pairs and at the rear in sets of three. 300. Ammunition supply system. — The ammunition car provided, Plate 129, is appa- rently a standard box car modified to the extent of being installed with interior equip- ment in the nature of an over- head trolley and end doors as well as side doors and shell racks. Each car is capable of carrying 29 projectiles in the center of the car and the pow- der charges for these 29 rounds. An overhead trolley is provided, with which it is possible to carry the projec- tile to either end of the car. Near one end of the car, Plate 130, is provided a support on which one end of the struc- tural-steel ammunition trans- fer beam rests. On this beam is shown the tray on which the projectile is placed and which is,moved forward by means of a chain operated by a hand- wheel at the forward end. When the projectile reaches the forward end of the trans- fer beam it is picked up by means of the chain hoist on 166 Plate 130 AMMUNITION TRANSFER BEAM. 167 the trolley attached to the armored roof, Plate 131, and is thence transferred forward to the ammunition table. From here it is rammed mechanically by means of the flexible chain, Plates 127 o Z! O o fa o Q Z: A. C. ogive 31-3-15 steel.. 27.0 ?6 20.0 V 28 27.0 ?S 128 oq C.S 38 36 17.8 in c. s 37.4 64 114 165 155 70 104 74 160 620 600 720 800 800 .600 650 465 .600 16.3 31 S? C.S 52.43 25.4 11 32.0 34 33.0 1'i 72.34 16.6 16 37 steel 90 300 15.1 IS Type "D" 17.5 11 4n MK VIII 172 173 341 64.5 27 14.9 41 H.E '!■> MK. Ill, H. E 41 41 II,Vg.,VIIg 386.36 106.4 770 4') 46 885 700 194 Projectile. Type. Weight. Weight of charge. Initial velocity. Length, base to point. Bange, Explosive. Propelling. elev. 1 Kg. Kg. Kg. M.-secs. Mm. Km. •) C. S 64.9 86 86 86 0.970 13. 155 5.52 5.52 5.52 770 400 400 400 15.4 1 11.5 ^ 11.5 5 fi 7 82 82 82 8.2 8.2 8.2 13.6 13.6 13.6 640 640 640 15.4 s 1-5.4 q C. S., F. A 15.4 10 11 ii n n • A. steel 140 140 160 160 25 25 20.2 614 614 526 610 16 A. steel ~ 12.9 17 p 34 14.9 IS 17.0 ?n A.T 216 216 33.5 33.6 42.7 7 643 790 18.8 *?] Steel 21.7 •ji ?i F.A.T.O.,C.S F.A.O.,C.S 270 300 23 25 79.3 11.3 740 322 21.9 9^ 8.5 9fi A.M.O 340 28 107.7 827 30.9 op A. C. 9-8-15 508 508 427 ■440 465 440 516 60 50 64.15 34 52.43 34 143.3 75.5 49.9 570 490 18.8 in 15.37 Steel 5-1-16 19.0 1915-1-5-16 153 850 30.7 F. A. Ogive, tronguo oasts. A. T. steel 58.2 535 16.5 ?6 17 Steel 840 180.2 66.3 530 * 16.1 10 11 A^ n II A 386 112 16 195 Projectile. Type. Weight. Weight of charge. Initial velocity. Length, base to point. Range, Explosive. Propelling. elev. 1 Eg. Kg. Eg. M.-seu. Mm. Km. 1. n F. A 81.5 81.5 SI. 5 6.9 6.9 6.9 473 473 473 12.3 4 do : n do 12 3 B Steel 86.35 85.35 85.35 16 16 16 11.8 11.8 11.8 666 565 666 S do q do 12 in 11 F. A. G 161.6 161.6 161.6 17.5 17.5 17.5 13.25 13.25 13.25 460 460 460 1? do 13 7 IS do 13 7 14 1S P. steel 163 163 160 163 256 237.5 261 34 34 16 34 20.2 20.2 620 620 Ifi do 17 D-C.5 IS 18.5 21.6 42.7 520 470 630 740 iq zn F.A.T.O Steel 17 29.4 20.5 ?i 24 4 m 23 F.A.C.S , A. T. steel 278 . 226 351.5 23 64 32 79.3 16.5 107.3 736 466 791 19.2 ?4 ■"i F. A. B 26 6 76 ?7 F. A., type B 351 31 107.4 791 » 2R W D.A.L.V.r F. A. L. V. F 387 387 440 427 540 465 710 36.8 36.8 34 64.15 21.65 52.43 58.5 66.9 37.4 60S 506 20.6 W 16.2 11 m 114 162 740 800 26 8 V. E-1-10-12 steel 26.4 M F. A., May, 1915 In C. S 63.1 475 W f- c. s 890 72.6 74 467 S q fl 1 • ? 1 1 5 1 1 45::!— 22- -14 19G ^ Projectile. Type. Weight. Weight of charge. Initial velocity. Length, base to . point. Range, max. carr. elev. Explosive. Propelling. 1 Kg. Kg. Kg. M. sees. M.v. Km. ■>. Steel stirap 45 82 82 82 13. 7 son 13. 400 3 D.-C.S D.-C. S 8.2 8.2 8.2 7.2 7.2 7.2 470 470 470 12. 800 4 12.800 5 D.-C.S - n 7 F. A. 83.5 83.5 83.5 1,3.6 13.6 13.6 638 638 638 16. 500 8 F.A.O F.A.O 16.500 q 16.500 in 11 li? 13 14 IS Ifi 17 A 140 26 25 614 12.900 IS 1<1 1l^ ?i ?i? ?3 1 1A ?^ ?6 . /. ?7 Steel 350 30 107.3 795 > 27. 400 ?S ' ?q OgiveC. S 392 357 4fi.'> 36.5 39 52.43 56.9 37.4 609 606 20. 150 30 15.440 31 F. A.C.S 18.300 3' 33 34 3'i 3fi 37 3S 3Q 'in 41 4? • ■13 44 ¥\ 46 o