UC-NRLF 7M D7E No. 1659 UF ; HANDBOOK OF THE * 7 3-INCH GUN MATERIEL MODEL OF 1902 WITH INSTRUCTIONS FOR ITS CARE (THIRTY-THREE PLATES) AUGUST 1, 1905 REVISED MAY 10 t 1906 REVISED JULY 17, 1908 REVISED JULY 1, 1911 REVISED JUNE 24, 1912 REVISED AUGUST 3, 1915 REVISED JUNE 5, 1917 WASHINGTON GOVERNMENT PRINTING OFFICE 1917 GIFT OF No. 1659 HANDBOOK OF THE 3-INCH GUN MATERIEL MODEL OF 1902 WITH INSTRUCTIONS FOR ITS CARE (THIRTY-THREE PLATES) AUGUST i, 1905 REVISED MAY 10, 1906 REVISED JULY 17, 1908 REVISED JULY 1, 1911 REVISED JUNE 24, 1912 REVISED AUGUST 3, 1915 REVISED, -JUNE. 5, 1917 WASHINGTON GOVERNMENT PRINTING OFFICE 1917 5 I'-n - WAR DEPARTMENT, OFFICE OF THE CHIEF OF ORDNANCE, Washington, June 5, 1917. This manual is published for the information and government of the Regular Army and National Guard of the United States. By order of the Secretary of War : WILLIAM OROZIER, Brigadier General, Chief of Ordnance. (3) CONTENTS. Page. List of plates 9 List of equipment 11 Guns, weights, dimensions, etc 13 Gun, model of 1902, description 13-14 Breech mechanism, model of 1902 gun 14-20 Nomenclature of parts 14 Description 14-17 Action of 17-18 Dismounting and assembling parts of 18-20 Care of the gun 20 Gun, model of 1904, description 20-22 Gun, model of 1905, description * 22 Breech mechanisms, model of 1904 and 1905 guns 23 Description 23-28 Action of 29 To dismantle the firing mechanism 29-30- To dismantle the breech mechanism 30 Range tables 31-34 Service table for shell and shrapnel 31-32 Complete range table for shrapnel 33-34 Ammunition 34-40 Cartridge case 34-35 Primer 35-36 Powder charge 36-37 Projectiles 37-39 Cast-iron shell 37 Common steel shell 37 Common steel shell, point fuze 38 Common shrapnel 38 Ehrhardt high-explosive shrapnel 39 Semple tracer 39-40 Fuzes ' 40-46 Ehrhardt combination 40-43 F. A. combination 43-46 Marking on ammunition packing boxes 46-47 Subcaliber cartridge 47-48 Drill cartridge 48 Subcaliber and drill cartridge kit 48 Allowance of ammunition 48 Blank ammunition 48-49' The cartridge case 49 1 The primer 49- The charge 49 Preparation of blank metallic ammunition 49-50 Precautions to be observed 50 Care of cartridge cases 50-51 (5) Page. Reloading and cleaning outfit 51 Misfires and hangfires 51-52 Fuze setters, model of 1905M 52-59 Bracket 53-55 Hand 55-56 Fuze setter hand, model of 1912 56-59 Carriage ' 60-87 Weights, dimensions, etc 60 Nomenclature of parts 60-66 Description 67-78 Dismounting and assembling gun and carriage 78-85 Care and cleaning of parts 85-87 Gun limber, model of 1902 88-93 Weights, dimensions, etc , 88 Nomenclature of parts 88-90 Description 90-93 Caisson, model of 1902 93-101 Weights, dimensions, etc . . '. 93 Nomenclature of parts 94-96 Description 96-101 Caisson limber, model of 1916 101-106 Weights, dimensions, etc 101 Nomenclature of parts 101-103 Description 103-106 Caisson, model of 1916 .....' 107-115 Weights, dimensions, etc 107 Nomenclature of parts 107-109 Description 109-115 Converted limber, model of 1908 115-119 Weights, dimensions, etc 115 Nomenclature of parts 116-118 Description 118-119 Converted caisson, model of 1908 119-124 Weights, dimensions, etc 119 Nomenclature of parts 119-123 Description 123-124 Forge limber 124-127 Weights, dimensions, etc 124 Nomenclature of parts 124-125 Description 125-127 Forge limber, model of 1902Mi 127 Description 127 Converted forge limber, model of 1908 127-130 Weights, dimensions, etc 127 Nomenclature of parts 127-129 Description 129-130 Battery wagon, model of 1902 130-135 Weights, dimensions, etc 130 Nomenclature of parts 130-132 Description 132-135 Converted battery wagon, model of 1908 135-138 Weights, dimensions, etc 135 Nomenclature of parts 135-137 Description ". 138 Page. Store limber 138 Weights, dimensions, etc 138 Description 138 Articles carried in 138 Store limber, model of 1902Mi 138 Description 138 Store wagon, model of 1902 139 Weights, dimensions, etc 139 Description 139 Battery and store wagon, model of 1902Mi 139-144 Weights, dimensions, etc 139 Nomenclature of parts 140-143 Description 143-144 Cyclometer 144-145 Description 144 Nomenclature of parts 145 Padlock and bolt snaps 145 Artillery harness 145-146 Nomenclature of parts 145-146 Steel collars 147-149 Directions for fitting 147 Table of dimensions 148 Collar-lifting device 149 Breast collar harness 149-151 Description 149 Nomenclature of parts * 150-151 Care and preservation of leather 151-152 Sights. 153-155 Line sight 153 Front sight 153 Rear sight 153-155 Care of the sights 167-168 Panoramic sight, model of 1904 -. . 155-158 Description 155-158 Use of 166-167 Care of 168-169 Panoramic sight, model of 1915 158-164 Description 158-164 Use of 166-167 Care of 168-169 Range quadrant 164 Description 167 Use of : 166 Care of 169 Adjustment of sights and quadrant 169-174 Pangramic sight, model of 1904 170 Panoramic sight, model of 1915 170 Front and rear sight 171 Range quadrant , 171 Verification of parallelism of lines of sight and axis of bore 172-173 Additional tests 173-174 Spare sights and quadrant 1 74 8 Page. Adjusting instruments , 174 Accuracy of fire 174-179 Causes of inaccuracies 174 Inaccuracies for Percussion fire 174-175,181 Time fire 175-181 Range errors 175-177 Probable zones 177-178 Table of probability factors 178-179 Painting artillery materiel 181-182 Oils for artillery materiel 182-183 Repairs for Field Artillery materiel issued to the United States Army and the National Guard 183-184 Suggestions for care and maintenance of materiel 184 -186 General information with reference to ordnance supplies for Field Artillery. 181-187 Method of loading a 3-inch gun battery for transportation by rail 187-188 Total equipment of a field battery, together with expendable supplies 189-203 Index.., . 205-216 LIST OF PLATES. Faces page I. 3-inch field guns, models of 1902, 1904, and 1905 13 II. Breech mechanism, assembled, model of 1902 14 III. Breech mechanism, assembled, models of 1904 and 1905 23 IV. Curves of corrector setting for fuze setter 34 V. Projectiles 35 VI. 21 second combination fuze 43 VII. Subcaliber and drill cartridges 47 VIII. Fuze setters 52 IX. Carriage, side elevation 66 X. Carriage, plan 67 XI. Recoil controlling mechanism 68 XII. Elevating gear 73 XIII. Traversing gear 74 XIV. Limber, model of 1902, side and rear views .*. . 90 XV. Caisson, model of 1902, side and rear views 96 XVI. Caisson, model of 1902, plan view 97 XVII. Caisson limber, model of 1916, side and rear views 103 XVIII. Automatic pole support, vertical section 104 XIX. Caisson, model of 1916, front and side views 108 XX. Caisson, model of 1916, plan view 109 XXI. Band brake and caisson carrying springs Ill XXII. Converted limber, model of 1908 118 XXIII. Converted caisson, model of 1908, 123 XXIV. Battery wagon, model of 1902 132 XXV. Converted battery wagon, model of 1908 138 XXVI. Artillery harness 145 XXVII. Spare parts of steel collar 148 XXVIII. Collar lifting device 149 XXIX. Breast collar harness 148 XXX. Rear sight 153 XXXI. Panoramic sight, model of 1904 155 XXXII. Panoramic sight, model of 1915 158 XXXIII. Range quadrant 164 (9) LIST OF EQUIPMENT PERTAINING TO ONE 3-INCH GUN BATTERY ON WAS, FOOTING. Num- ber. Equipment. Property classification. Class. Section. 4 3-inch field guns, models of 1902, 1904, or 1905 .................................... 4 3-inch gun carriages, model of 1902; each equipped with fixed sights, adjustable rear sight, panoramic sight, and range quadrant ............................... IV , 16 I 3-inch gun limbers, model of 1902, 1916, or converted 1908 ..................... 12 Caissons, model of 1902, 1916, or converted 1908 ................. ............... 1 Forge limber, model of 1902, 1902 Mi, or converted 1908 ....................... 1 Battery wagon, model of 1902, 1902 Mi, or converted 1908 ...................... 1 Store limber, model of 1902 or 1902 Mi ......................................... ... IV 9 1 Store wagon, model of 1902 or 1902 Ml ......................................... 37 Sets of artillery harness (lead) or breast collar harness ............................ 19 Sets of artillery harness (wheel) or breast collar harness ....................... 1 Set of pack harness .............................................................. IX 5 1 Set of F. C. equipment .......................................................... V (ID HANDBOOK OF THE 3-INCH GUN MATERIEL. THE 3-INCH FIELD GUNS, MODELS OF 1902, 1904, AND 1905. Weight : Models of 1902 and 1904 ______________________________ pounds 835 Model of 1905 ___________________________________________ do ____ 788 Caliber ___________ ________________________________________ inches 3 Total length ________________________________________________ do ---- 87. 8 Length of bore ______________________ _ _______________________ do__ __ 84 Length of rifled portion of bore ___________________ i ____________ do ____ 72. 72 Rifling : Number of grooves ____________________________________________ 24 Width of grooves _________________________________________ inch__ 0.2927 Depth of grooves _______________________________________ do ---- 0. 03 Width of lands _________________________________________ do ____ 0. 1 Models of 1902 and 1904 : 1 turn in 50 calibers at origin to 1 turn in 25 calibers at 12.52 inches from muzzle, thence uniform. odel Qf 1905 . Q turng ftt or . gin to I turn . n 25 calibers at 9.72 inches from muzzle, thence uni- form. Weight of projectile, filled and fuzed ______________________ pounds __ 15 Weight of cartridge case ___________________________________ do ____ 2. 25 Weight of fixed ammunition (1 round)-- ____________________ do ____ 18. 75 Capacity of cartridge case __________________________ cubic inches __ 66. 5 Muzzle velocity __________________________________ feet per second 1, 700 Maximum pressure per square inch _______________________ pounds __ 33, 000 Range at 15 elevation _______________ : _____________________ yards 6, 000 Maximum range, about _____________________________________ do ____ 8, 500 Twist, right-hand. DESCRIPTION OF THE 3 -INCH FIELD GUN, MODEL OF 1902. [Plate I.] The gun is built up of nickel steel, consisting of a tube, jacket, lock- ing hoop, and clip. The jacket envelops the rear portion of the tube and projects beyond it to form the breech recess or seat for the breech mechanism. A lug, known as the " recoil lug," projects from the under surface of the jacket at its extreme rear end and affords a point of attachment for the recoil cylinder of the carriage. The locking hoop is shrunk on the tube and forward end of the jacket and secures the latter against rearward movement on the tube under (13) 14 firing stresses. The clip is a short hoop shrunk on the tube near the muzzle.' On the underside of the gun, extending the entire length of the jacket, locking hoop, and clip, are formed two recoil guides or clips, which fit over and secure the gun to the guide rails of the cradle. When the gun is assembled upon the carriage, that portion of the cradle rails between the locking hoop and clip is covered by a sheet- steel dust guard, so that the bearing surfaces of the recoil clips and guide rails are thoroughly protected from dust and dirt. Eight oil holes, closed by handy oilers, are provided for oiling the guide rails of the carriage. Nomenclature of breech mechanism for the model of 1902 gun. Num- ber. Name of part. * Location. Property clas- sification. Class. Sec- tion. 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 Breechblock IV 3 Breechblock bushing Front end of block Breechblock cover Rear find nf blnok Breechblock stop Screwed into fi ont face of carrier Cover locking pins Secure cover to block Block carrier Hinged to jacket' supports block Hinge pin Hinges carrier to jacket Hinge-pin catch In hinge pin . Latch Dolt In recess in carrier Latch-bolt spring Around latch bolt ... *. Firing pin In axial hole through block Firing-pin spring Around firing pin Cap Screwed on rear end of firing pin Cocking lever Seated between block and cover Sear In recess in block Sear spring . . . do Trigger In seat in block carrier Trigger spring do . . Trigger arm Mounted on trigger-arm sleeve Trigger-arm sleeve In bearing in recoil lug Split pin, taper Secures trigger arm to trigger-arm sleeve. . . . Pivoted on block carrier Operating lever Operating-lever pivot Pivots lever on block carrier. Lever-pivot key . Sfifinrps nivnt in seat. Lever latch | Tn nnp.rfttinpr IP.VPV Lever-latch catch Screwed into rear face of carrier Lever-latch pin Secures latch to lever Lever-latch spring In recess in spring seat Extractor... In breech recess Extractor lever Mounted on hinge pin Lever-guide screws, 1 long, 1 short. . Spring seat Fasten guide to block carrier Screwed into operating lever Cylinder locking stud Sfiat.ftd in rfiroif liip DESCRIPTION OF THE BREECH MECHANISM FOR THE MODEL OF 1902 GUN. [Flate II.] The breechblock is of the interrupted-screw type. It has two threaded and two flatted sectors, in rear of which is a cylindrical sec- tion, smaller in diameter, on which is a square screw thread for secur- ing the block to the block carrier. The breech recess of the gun is threaded and slotted to correspond with the threads on the block. The latter is bored out axially to form a seat for the firing pin. The 15 front of this axial hole is closed by the breechblock housing, which is screwed into position and held by a set screw through the breech- block. The rear end is closed by the breechblock cover, which is held by means of undercut grooves in the block and lugs on the cover and locked in place by the two cover-locking pins. A hole through the breechblock and breechblock bushing affords a vent for any gases escaping from a ruptured primer. For repairing worn breechblock bushings, another bushing is inserted in the end of the present one. The block carrier is hinged on the right side of the breech recess by the hinge pin, the carrier is bored out and threaded, and the breechblock rotates and is held in this opening by the square threads mentioned above. A stop for limiting the rotation of the breechblock when in its open position is fitted in a suitable position on the front face of the block carrier. The latch bolt is located in a seat bored in the carrier and is con- stantly pressed forward by its spring. When the block is rotated so that its threads are disengaged from those in the gun, a recess in the rear face of the block comes opposite the front end of the latch bolt, and when the block and carrier are swung away from the breech the latch bolt enters this recess, thus locking the block to the block carrier. The block is unlocked by the latch bolt coming in contact with the rear face of the gun in the act of closing the breech. The operating lever is pivoted on a seat formed by a lug on the carrier. The lever has a handle on its outer end and bevel-gear teeth on its pivot end which mesh with corresponding teeth formed on the rear of the face block. A lug on the operating lever prevents the shock of stopping the rotation of the breechblock from being taken up on the last tooth of the bevel gear on the operating lever. The lever latch, with its spring, is assembled in a recess in the operating lever by the latch pin ; when the breech mechanism is closed the catch on the inner end of the latch engages a catch formed on a lug screwed into the rear face of the block carrier and locks the operating lever to the carrier. When the operating-lever handle is grasped to open the breechblock, pressure on the lever latch disen- gages its catch from this lug. The spring seat is secured to the operating lever by screwing it into its seat with a teat wrench. After it is once screwed tightly home it should not be removed. The top of the spring seat affords a hard bearing surface for the operating lever guide. The lever catch spring is assembled in the spring seat. The operating-lever guide is a strong spring fastened by two screws one long and one short to the rear face of the block carrier and prevents any upward movement of the operating lever which 10261417 2 16 might unlatch it from the block carrier when the battery is moving over rough terrain. The firing pin has guide lugs near its front end \vhich run in slots in the breechblock bushing. The point of the firing pin projects through a hole in the center of this bushing when the gun is fired. A cap, having a square cross section, is screwed on the rear end of the firing pin and passes through a square hole in the cover ; its rear end terminates in a ring for recocking the firing mechanism by hand without opening the breechblock. A shoulder on the cap forms a catch for the sear. The firing pin is eccentrically located in the block; in the firing position it is in alignment with the axis of the gun and in line with the percussion primer of the cartridge. As the block is rotated to open the breech the pin is moved to one side clear of the primer and remains in that relative position until the block is again rotated in closing the breech. The cocking lever has a ball-and-socket bearing in the block car- rier; the other end of the lever is U-shaped, the forks straddling the firing pin. The middle part of the cocking lever works on cam sur- faces on the rear face of the breechblock and on the front face of the cover. The front face of the cocking lever has two lugs or ribs which support it on the cam of the block; its rear face is provided with a stud or pin, which serves to prevent its improper assemblage. The firing-pin spring is assembled around the firing pin, with its rear end bearing against the forks of the cocking lever and its front end against the guides on the pin. The sear works in a slot in the breechblock and is held against the cap on the firing pin by a sear spring. The trigger works in a slot in the block carrier and is urged upward by the trigger spring. As the block is rotated in being closed the trigger engages with the sear, and by pulling on the trigger the gun is fired. When the block is unlocked the trigger is disengaged from the sear and the gun can not be fired. The trigger -arm sleeve is seated in a bearing in the right side of the recoil lug on the gun; it is provided with a central hole, the forward part of which is square and is flared, and into which the rear end of a 'square firing shaft, attached to the cradle of the carriage, enters when the gun is in battery. The trigger arm is mounted on the rear end of the sleeve, and its free end engages a notch in the outer end of the trigger. Revolving the firing shaft rotates the sleeve, the trigger arms thus pulling the trigger and firing the piece. The extractor is ring shaped, with two lips which engage on oppo- site sides under the rim of the cartridge case. It has two guides on the right side sliding in grooves in the breech recess, and in the web connecting these guides is a beveled slot in which the wedge-shaped end of the extractor lever works. 17 The extractor lever is cam shaped, is pivoted on the hinge pin, and . bears against the rear face of the slot in the gun. It is operated by the block carrier first coming into contact with its outside cam sur- face and then with its short arm as the block is opened. The hinge- pin hole in the extractor lever is elongated and of such shape as to cause the lever first to act. as a wedge on the extractor and then to move it quickly to the rear. ACTION OF THE MECHANISM. The following movements take place when the breech mechanism is opened: The first 117 motion of the operating-lever handle ro- tates the block until the threaded sectors are disengaged. The next 90 motion swings the block and block carrier (the two being locked together by the latch bolt) around the hinge pin, leaving the breech- block clear of the recess and its axis at right angles to that of the gun. As the block is rotated about its axis, the pitch of the threads forces the breechblock to the rear and at the same time the cam surface on the rear face of the breechblock forces the cocking lever to the rear, thereby retracting the firing-pin point within the breech- block, in which position the firing pin is held by the sear. It will be noted that the firing-pin spring is compressed as the block is closed. The firing pin should be released from the sear when the gun is not in use. As the block carrier swings around the hinge pin it first causes the extractor lever to jnove toward the axis of the gun and start the cartridge case from its seat by its wedge action on the extractor; later the block carrier strikes against the short arm of the extractor lever, causing the extractor to move sharply to the rear and thus ejecting the cartridge case from the gun. When the breech mechanism is closed the following movements take place : In the first 90 motion the block and block carrier swing around the hinge pin, releasing the block carrier from contact with the extractor lever, which leaves the extractor free to be moved for- ward by the breechblock and cartridge case. As the carrier comes into contact with the face of the breech the latch bolt is forced to the rear, unlocking the block from the carrier. During the last 117 motion of the operating lever the bevel gears rotate the breechblock until its threaded sectors are engaged with those in the breech recess. At the end of this 117 swing the operating lever is locked to the gun by the lever latch. As the block is rotated about its axis the pitch of the interrupted screw threads forces it slightly to the front, finally seating the cartridge in the chamber. During the rotation of the block around its axis the cam surface on the cover forces the cocking lever forward, thereby compressing the firing-pin spring. When the rotation of the block is completed this compression is a maximum. The gun may be fired either by a lanyard attached to the trigger or by means of a firing handle on the cradle. 18 If the sear fails to trip and release the firing pin, thus causing a misfire, the operating lever should be revolved equal to one tooth of the gear and then closed. This will bring into engagement the trig- ger and sear and allow the proper action of the mechanism. The above condition or misfire can be produced by keeping a ten- sion on the trigger while the block is being rotated to the closed position. TO DISMOUNT AND TO ASSEMBLE PARTS OF THE BREECH MECHANISM. No tools are required for these operations except, possibly, a hook for removing the cover locking pins. The lanyard hook can be used for this purpose. In general, the different parts are easily assembled by hand, and no forcing is required and none should be permitted. No part of the mechanism should be struck directly with a hammer. In case it is found necessary to use force (as, for example, to remove the lever latch pin) a copper drift or a piece of wood should be interposed between the part and the hammer. To remove the cover: Remove the cover locking pins by pulling them directly to the rear; open the breech of gun; slip cover from its seat. To assemble the cover : Open the breech of gun ; slip the cover into its seat on the rear face of block; insert cover locking pins into the locking-pin holes, forcing the pins directly to the front through the cover into the block. To remove the cap, firing pin, firing-pin spring, cocking lever, sear, and sear spring: Remove cover as above; rotate block partly to its closed or locked position; unscrew cap; cocking lever, firing-pin spring, firing pin, sear, and sear spring may now be removed in the order named. To assemble the above-named parts: Rotate the breechblock to a position midway between its open and closed positions ; insert in their seats in the order named the sear spring, sear, firing pin with firing- pin spring assembled on it, cocking lever (with stud pin to the rear), and finally screw the cap home on the end of the firing pin until the cylindrical pin on the rear end of the pin is flush with the hole in the body of the cap, rotate the block to the unlocked or open position and assemble cover. To dismount the operating lever: Remove the cover and unscrew the cap as above ; remove lever-pivot key and lever pivot ; operating lever may be now lifted from its seat. To assemble the operating lever : Remove cover and cap as above ; place operating lever on its seat with gear teeth meshing correctly with those on block ; insert lever pivot and lever-pivot key ; assemble cap and cover as described above. To dismount the lever latch : Remove the lever latch pin by pulling or shoving it from its seat. The latch and latch spring may now be 19 removed from the lever. The lever latch and spring are assembled by placing them in their seats in the lever and then inserting the lever latch pin. The latter is a straight pin, split at its inner end to hold it in its seat. To dismount the trigger: Remove cover and small parts of firing- mechanism; open the breech and remove the operating lever; press the latch bolt against the face of the carrier and rotate the breech- block by hand pasij its closed position ; after one and one-half revolu- tions of the block, the trigger will be free and may be lifted from its seat. The trigger spring is also free and may be removed. To assemble the trigger and trigger spring: The operating lever and small parts of mechanism are supposed to be dismounted. Un- screw the breechblock from the carrier until the trigger spring and trigger can be slipped from the bore of the carrier into their seats; place them in position, and by means of a lanyard hold the trigger outward against its spring in order to prevent burring or injury to the breechblock as the latter is screwed into the block carrier ; screw block into carrier and assemble operating lever and small parts of mechanism as described above. To dismount the breechblock: Remove cover and small parts of mechanism; dismount operating lever; press latch bolt against face of carrier and unscrew breechblock from the block carrier (approxi- mately 1.66 turns of block are required to unscrew it). To assemble the breechblock to the block carrier : Screw the block into- the carrier, assembling trigger spring and trigger. To dismount latch bolt and spring : Open the breech of gun, press the latch bolt into the carrier far enough to unlock the block, and rotate the latter in the block carrier to its closed position. Press the latch bolt into the block carrier until the lug on the rear end of the bolt clears the rear face of the carrier; now revolve the bolt 180 on its axis and release it. Its spring will force it forward out of its seat. To assemble the latch bolt and spring : With the breech open, rotate the block in the block carrier to its closed position; put the latch bolt (with spring assembled) in its seat in the carrier; press it back against its spring until the lug on the rear end of the bolt clears the rear face of the block carrier, and then revolve the latch bolt 180 on its axis. Remove the pressure and the bolt will assume its proper , position. NOTE. The latch bolt is an auxiliary and not an absolutely essen- tial part of the breech mechanism, as the gun may be safely fired without it. This should be done only in emergencies. In firing* without the latch the breech must be opened and closed slowly and gently to insure the correct sequence of the swinging and rotating: motions. 20 To dismount the block carrier, extractor, and extractor lever : Open the breech of the gun and remove the hinge pin; the carrier, ex- tractor lever, and extractor may now be removed from their seats. To mount the block carrier, extractor, and extractor lever : Place the extractor in its seat in the breech recess; place the carrier in position with its hinge hole registering with the holes in the hinge lugs of the jacket; place the extractor lever in position with its small end in the slot in the extractor web and its flat side to the front ; insert the hinge pin. To dismount the trigger arm and trigger-arm sleeve: Kemove taper split pin from trigger arm ; the latter may then be moved to the rear off of the sleeve; shove the piece a few r inches from battery: the sleeve may then be slipped to the front from its seat in the recoil Ing. CARE OF THE GUN. . After firing, the bore of the gun should be cleaned to remove the residue of smokeless powder, and then oiled. In cleaning, wash the bore with a solution made by dissolving one-half pound of sal soda in 1 gallon of boiling water. After washing with the soda solu- tion, wipe perfectly dry, and then oil the bore with a thin coating of the light slushing oil furnished for the purpose. A slush brush for use in oiling the bore will be issued by the Ordnance Department upon requisition. The breech mechanism should be kept clean and well oiled. It should be dismounted from time to time for examination and oiled when assembled. To relieve the firing-pin spring of unnecessary strain the firing pin should always be uncocked when the .gun is not in use. This applies to guns, model of 1902 only. The spare parts carried in the trail box or in the battery wagon should be well coated with vaseline or heavy oil and each piece then wrapped in paper to prevent the oil from being rubbed off. DESCRIPTION OF THE 3 -INCH FIELD GUN, MODEL OF 1904. [Plate I.] The 3-inch field gun, model of 1904:, uses the same ammunition as the 3-inch field gun, model of 1902, and the guns are practically the same, with the exception of the breech mechanism. The gun is a built-up construction of nickel steel, and consists of a tube, jacket, locking hoop, and clip hoop, which is shrunk on near the muzzle of the gun. The locking hoop serves to secure the jacket from any longitudinal movement to the rear, and is joined to the forward end of the jacket by means of a screw thread employing one and one-half turns to set it in place. A shoulder in the hoop bears against a shoulder on the tube. By this means the jacket is held up tight against the shoulder 21 on the tube. The locking hoop in addition to being screw threaded is put on with a shrinkage. The clip extension on the front end of the locking hoop for guns of this model has been omitted. This makes a different dust guard necessary for these guns. The clip hoop is put on with a shrinkage; a cylindrical surface having a shoulder formed thereon is formed on the tube near its muzzle, which serves as a seat for the clip. The clip, in addition to being shrunk on, is secured by means of a key at its rear end, on the under surface, and a pin, which is driven in a horizontal position transversely through the hoop near its front end. The jacket and locking hoop are provided on their lower element with clips made integral thereto, which fit corresponding guide rails on the carriage. These clips serve to guide the gun during recoil as well as to hold it on the carriage. At the rear end of the jacket and at its lower element a lug is formed, to which the hydraulic cylinder is secured ; there is a projec- tion from this lug on the right side, to which is connected the firing device. Along both sides of the gun and clip hoop, handy oilers are provided for oiling the guide rails of the carriage. The gun is provided with the regular cartridge-case chamber, which is connected to the main bore by a short cone. The rifling is semicubic parabola in form, having an increasing twist, beginning with one turn in 50 calibers and increasing to one turn in 25 calibers, to within 12.52 inches of the muzzle. From this point the twist is uniform one turn in 25 calibers to the muzzle. The firing device consists of a bracket (bolted to the cradle of the carriage), firing handle, handle-return spring, shaft-return spring, firing-handle shaft, pallet shank, pallet, tripping collar, and adjust- ing screw. The bracket has a cylindrical portion, the cylinder hav- ing a central diaphragm or partition. In the rear portion of this cylinder is fitted the shaft-return spring, which acts on the firing- handle shaft that is, this spring causes the firing-handle shaft to return to its normal position after the sear has been tripped and the gun fired. The firing-handle shaft returns to its normal position, no matter whether the operator releases his tension on the firing handle or not. In the forward portion of the cylinder the handle-return spring is fitted. This spring is employed to hold the firing handle in a horizontal position convenient for firing the gun. The firing handle is mounted loosely on the forward end of the firing-handle shaft and is connected therewith by means of a trip- ping collar and latch. The tripping collar is provided with a squared opening which fits over a correspondingly squared end on the for- ward end of the firing-handle shaft. The hub of the firing handle is provided with a trip latch so arranged that the latch is in engagement with a notch in the periph- 22 ery of the tripping collar. By this means the firing handle is tem- porarily made fast to the firing-handle shaft. By a sufficient down- ward movement of the firing handle, the lower end of the trip- latch plunger is caused to come in contact with the adjusting screw, which is suitably located in the firing bracket. This engagement between the lower end of the trip-latch plunger and the adjusting screw forces the plunger upward, thus releasing the trip latch and allowing the firing-handle shaft to return to its original or normal position. The firing handle is arranged so that it can be folded back and out of the way for traveling purposes. The handle is hollow and is provided with a plunger, coil spring, and an adjusting or tension plug, which is screwed in or out by means of a screw- driver until the desired tension on the spring is obtained. One end of the plunger bears against a flat surface on the firing-handle hub and the friction produced by the tension of the spring tends to hold the firing handle in either the folded or open position. The rear end of the firing-handle shaft is square in cross section and tapered to a point at the end. This squared end projects far enough to the rear to pass through the pallet shank, which is revolv- ably mounted in a projection on the recoil lug of the gun. On the rear end of the pallet shank is mounted the firing pallet, which is held in place by a taper .split pin. It has a projection which engages a projection on the lower end of the trigger shaft, and by pressing downward on the firing handle the following results follow: The firing-handle shaft is rotated, the shaft-return spring is put under additional tension, the pallet shank rotates, with the firing pallet thereon; this in turn rotates the trigger shaft, which by means of the firing-spring sleeve and trigger fork compresses the firing spring until such time that the front end of the firing-spring sleeve trips the sear and releases the firing pin. [Plate I.] The 3-inch field gun, model of 1905, is similar to the 1904 model, except that it is about 50 pounds lighter (this is accomplished by a reduction in the outside diameters of the gun), and that the exten- sion of the clips to the rear on the clip hoop have been omitted. This necessitates a special dust guard between the front end of the locking hoop and the rear end of the clip hoop. The rifling in the guns of this model is also different from that in the guns, models of 1902 and 1904. It starts with turns at origin, and increases to 1 turn in 25 calibers at a point 9.72 inches from the muzzle, thence uniform, 1 turn in 25 calibers, to the muzzle. Handy oilers are em- ployed instead of spring covers for oiling the guide rails of the car- t riage. This gun employs the same ammunition as the 1902 and 1904 models. 23 BKKK( I! MKCH. \.\1SM. [Plate III.] The breech mechanisms of the guns, models of 1904 and 1905. are similar in every respect and are interchangeable. The breech- block is of the interrupted-screw type, and is provided with four- threaded and four-slotted sectors. The front end of the axial recess in the block for the hub of the block carrier is closed by a bushing. Four ventholes leading from a cavity in the bushing rearwardly through the breechblock permit the escape of gas from a ruptured primer. On a semicircular boss on the rear face of the breechblock are cut gear teeth, in which the gear teeth of the operating lever bevel gear mesh. The upper end of the circular boss on which the gear teeth are cut serves as a stop to limit the rotation of the block in the unlocked position. This upper end of the circular boss comes in con- tact with a hardened steel stop riveted to the inner face of the block carrier. A radial lug or tooth projects from the inner surface of the circular boss on the breechblock and engages an L-shaped groove cut in the hub of the block carrier, so that when the mechanism is unlocked no relative movement between the breechblock and carrier can take place. In order to surely maintain this relation between the breechblock and block carrier, a block latch, pivoted on the inner face of the carrier in the lower left-hand quadrant, engages a notch or shoulder cut in the rear face of the block adjacent to the circular hub on which the gear teeth are cut. This latch is so pivoted that as the mechanism is swung free from the gun it moves forward suf- ficiently to engage the notch in the block, and also to cause the for- ward plane of the latch to project forward of the front face of the block carrier; consequently when the mechanism is swung to the closed position the front face of the latch comes in contact with the rear face of the breech of the gun, thus forcing the latch out of the notch in the breechblock back into a recess in the carrier, and by con- tinuing the motion of closing the mechanism the breechblock is free to rotate on the hub of the carrier and engage its threads with those in the gun. When the breechblock is in the locked position a lug on the firing-lock case engages the front face of the tooth or lug on the breechblock, which locks the breechblock to the carrier. This en- gagement between the lug on the breechblock and the lug on the firing-lock case serves to lock the carrier to the breechblock and pre- vent displacement due to a blowback. This is accomplished through the medium of four additional lugs on the firing-lock case, which nre arranged to interlock with corresponding lugs on the carrier. The breechblock is mounted eccentrically in the breech of the gun with reference to the axis of the bore, and is concentrically mounted on a hub on the block carrier, in which the firing-lock case is fitted. 24 The firing-lock case is eccentrically fitted in the hub of the block carrier, in such a position that the axis of the firing pin is always in line with the bore of the gun. The bushing in the front end of the breechblock, through which the firing pin passes, when in the fired position, is fitted eccentrically with reference to the breech- block and the bushing is provided with a cavity of such dimensions that the breechblock is permitted to revolve freely about the firing pin, /which is fixed in the hub of the block carrier and does not rotate. The point of the firing pin, when at rest, is always within the enlarged cavity in the bushing, and when the block is revolved to the unlocked position the hole in the bushing through which the point of the firing pin passes is moved to one side, due to the eccen- tric arrangement of the breechblock, thus masking the point of the pin and preventing any possible contact between the firing pin and the primer in the cartridge case when the block is unlocked. The block will be practically fully locked before any contact between the firing pin and primer can take place. The firing pin is provided with a shoulder a short distance in rear of its forward end, which comes in contact with the rear face of the bushing if an attempt is made to fire the gun when the breech is unlocked. This is done to prevent any possible blow coming on the point of the firing pin and injuring the same. The firing mechanism belongs to that type known as a continuous- pull mechanism ; that is, no cocking of the firing pin is required other than a pull on the lanyard or a downward pressure on the firing handle. This arrangement permits of repetition of the blow from the firing pin in case of a misfire as often as desired without the opening of the mechanism or recocking the firing pin. FIRING PIN. The firing pin is mounted in the firing-lock case and near its front end is provided with a collar which serves to guide the pin axially and as a shoulder for the front end of firing spring, and also serves as a means for locking the firing pin by the sear until such time that the firing spring has been compressed by the action of the fir- ing mechanism, and the sear released. The rear end of the firing pin is rectangular in cross section and is provided with a double lug against which the trigger fork engages at a point between its upper end and its axis. The engagement serves as a means of with- drawing the firing pin to its retracted or normal position, after the pin has been released and forced forward. Opposite the double lug for the trigger fork the firing pin is provided with another and smaller lug, which fits into a slot in the firing-spring sleeve and serves to hold the sleeve in its proper position. 25 FIRING SPRING. The firing spring is threaded over the firing pin from the rear end of the pin, and over this is assembled the firing-spring sleeve in such a manner that when it is seated in its proper position the firing spring is put under an initial tension by being compressed between the collar on the front end of the firing pin and a shoulder or seat formed on the inside of the sleeve at its rear end. One end of the firing spring is turned up to fit into a hole in the firing-spring sleeve in order to hold the spring at all times in its proper position. SEAR. The sear, which is in the form of a leaf spring, is seated in a slot in the firing-lock case and is provided with a thickened forward end, into which is cut a notch, in which a hardened portion of the periphery of the collar on the firing pin engages. Just to the rear of this notch in the sear an inclined surface is provided, upon which the forward end of the firing-spring sleeve acts in its forward motion to compress the spring and fire the gun. After the sleeve has trav- eled the required distance forward to. produce the proper compres- sion of the firing spring the sear is forced outward, thus releasing the engagement between the sear and the collar on the firing pin. On the rear end of the sear a cylindrical projection is formed, which fits into a hole drilled into the firing-lock case. This serves to hold the sear in place. TEIGGER FORK. The trigger fork is seated in the rear end of the firing-lock case, and is constrained from displacement laterally by the walls of the case, and is mounted on the upper squared end of the trigger shaft. The trigger fork is bifurcated on the end which engages the firing pin and sleeve, and it is seated so that the flat sides of the firing pin pass between the bifurcated end of the fork and the rear face of the bifurcated end bears against the front face of the double lug on the firing pin at a point located between the end of the trigger fork and its axis. This point of contact between the firing pin and trigger fork is important, as it helps to maintain the proper operation of the firing pin in its return action after firing. The extreme bifurcated ends of the trigger fork are made in the form of a circle, and these ends bear against a flat surface on the rear end of the firing-spring sleeve perpendicular to the axis of the sleeve, and do not touch the sleeve at any other point. This is important and is the main element which causes the firing pin to return to its normal position after firing. The firing spring is under tension at all times, and exerts an equal pressure between the collar on the front end of the firing 26 pin and its seat in the rear end of the firing-spring sleeve. These points of exerted pressure are in a direct line axially, and the pres- sures are equal ; but the point of contact between the bifurcated end of the trigger fork and the rear end of the sleeve being placed at a point outside of the normal line of pressure of the firing spring, the leverage and movements being such that the spring acting on the sleeve, which in turn is acting on the trigger fork, forces the latter to the rear, which in turn carries the firing pin to the rear, through the medium of the double lug on its rear end, against which the trigger fork bears. This action is due to the fact that the lever arm between the outer end of the trigger fork is greater than that between the spring and sleeve, and is simply a case of differential leverage. The firing pin assumes its normal position and is locked in place by the sear and is again ready for action. TRIGGER SHAFT. The trigger shaft is assembled in a projection which forms a part of the firing-lock case and is held in place by a wire detent. It has at its upper end a squared portion on which the trigger fork is mounted. At its lower end are two projections, the longer of which is provided with a hole for the attachment of a lanyard, by which the gun should be fired until the spade at the end of the trail is sufficiently embedded in the ground to hold the carriage in place. The other projection on the trigger shaft is acted upon by the firing pallet, w r hich is mounted on the pallet shank. The pallet shank is mounted in a bearing in the recoil lug of the gun, and the pallet shank telescopes the firing needle, which is square in section and is mounted in a bracket which is riveted to the cradle. This combina- tion of parts serves as a means for firing the gun from a seat on the carriage. FIRING-LOCK CASE. The firing-lock case is designed to contain the complete firing gear, and if necessary the entire firing mechanism can be replaced in an instant. It contains the firing pin, firing spring, firing-spring sleeve, sear, trigger fork, and trigger shaft and detent. It is provided with four lugs, by which it is locked in place in the hub of the block car- rier, and one lug which is forward of the other four, which engages behind a lug on the breechblock. This lug, together with the other four which lock the case to the carrier, serves to lock the block and carrier together. The firing-lock case is held from displacement due to rotation by a locking bolt. This locking bolt is fitted in a pro- jection of the case and its inner end enters a recess or seat in the rear face of the block carrier. 27 For the 1901 and 1905 models a firing-lock case stop, consisting of a rivet on the front face of the block carrier, has been provided to prevent an improper assembling of the firing-lock case. OPERATING LEVER. The handle and body of the lever is recessed to receive the lever latch. The inner end of the lever is provided with beveled gear teeth, which mesh with corresponding teeth on the breechblock and serve as a means for opening and closing the mechanism. The lever is seated between tAvo lugs on the block carrier and is held in place by a pivot. BLOCK CARRIER. The block carrier is hinged on its right side to the gun by means of the hinge pin. It is provided with a central, inwardly projecting hub. upon which the breechblock is concentrically mounted. The hub is bored out eccentrically to receive the firing-lock case, which is held in place from axial displacement by four lugs formed on the inside of the bore. In the forward end of the central hub a slot is cut Avhich extends to the rear and terminates in an L. This receives the lug on the breechblock and holds the block from displacement when the mechanism is open. TAVO lugs are formed on the rear face of the carrier just below its center. They form a seat for the operat- ing lever. On the inner face in the lower left-hand quadrant a seat and pivot for the block latch is pro\ided. In the upper right-hand quadrant on the inner face a hardened steel block stop is riveted. This limits the rotation of the block in the open position. On the right side of the block carrier two hinge lugs are provided, betAveen which the extractor lever is mounted. Also between these lugs is fitted a hardened steel pallet, which serves to operate the extractor. In the loAver circumference are drilled three ventholes for the escape of gas in case of a blowback. A catch for the lever latch is suitably located and screwed to the rear face of the carrier. It is held in place by a small pin driven in from the circumference of the carrier. BLOCK LATCH. A recess in the latch contains a spring Avhich presses against the inner face of the carrier, which forces the latch forward into its lock- ing recess in the block, when the breech is open. When the block is locked the latch rests against the rear face of the jacket. The latch serves to prevent rotation of the block to its closed position until it is forced baclrvvard by coming in contact with the breech of the gun. 28 EXTRA CTOB. The extractor slides in a groove cut in the breech recess and is operated by the extractor lever, the inner end of which enters a bev- eled slot in the extractor. A lip on the extractor engages the rim of the cartridge case and serves as a means for ejecting the same. EXTEACTOE LEVEB. The extractor lever is f ulcrumed on the hinge pin and bears against the front face of its seat in the gun. A cam formed on its hub is so Jocated that in swinging the carrier to the open position the extractor lever is forced inward, causing a wedging action and loosening the case. At a time near the end of the swinging movement of the carrier the hardened steel pallet on the carrier strikes a short arm on the extractor lever and ejects the case. LEVEB LATCH. The latch is fitted in a seat in the operating lever and serves to lock the handle from rotation, which in turn prevents rotation of the block. The latch is held in place by a long steel pivot, which is so fitted that it is held in place by the lever latch and the action of its spring. HINGE PIN. This is a hardened steel pin ground to fit, and is held from dis- placement by a hinge-pin catch fitted to its lower end. FIBING PALLET. The firing pallet is a steel piece provided with a short lever arm which engages the short arm on the trigger shaft. It is provided with a squared opening for assembling to the end of the pallet shank, and is held in place by the pallet pin driven through its hub tan- gential to the pallet shank. It is provided with a stud on its forward face, which enters a recess cut in the rear face of the recoil lug on the gun. This serves to hold the pallet and shank in their proper position during the recoil of the gun. PALLET SHANK. The pallet shank is revolvably mounted in a seat formed in the recoil lug of the gun and is held in place by a head on its forward end and the firing pallet on its rear end. The pallet shank is pro- vided with a square hole which is flared at its forward end to facili- tate the engagement between it and the firing needle during the counter-recoil of the gun. This piece serves as the direct connection between the gun and carriage for firing the gun. 29 ACTION OF THE BREECH MECHANISM. To open the breech, grasp the operating lever handle ; at the same time compress the level latch handle. This releases the latch from the catch on the block carrier. Rotate the operating lever to the rear. During the first part of this movement (67J) the block is rotated and its threads disengaged from those of the gun, at which time the stop on the block comes in contact with the stop on the block carrier and the block latch will drop into its notch in the block at the moment of swinging the carrier from the gun. The block is now locked against further rotation in either direction. During a further rotation of the operating lever of about 90 the block and carrier swing about the hinge pin clear of the breech recess, the pallet on the carrier forces the extractor lever inward, unseating the cartridge case before the end of the 90 movement, and finally ejects the case free of the gun. When another round is inserted the rim of the cartridge case comes in contact with the extractor and forces it partly home. Inclosing the mechanism the movements are simply the reverse of opening; as the block carrier comes in contact with the breech face of the gun, the block latch is forced rearward, unlocking the block from the carrier. Further rotation of the operating lever rotates the bleechblock, causing its threads to engage those of the gun. This engagement of threads moves the block forward, due to the pitch of the threads, and firmly seats the cartridge in the gun. At the final motion of the operating lever its latch engages the catch on the rear face of the block carrier, locking the block in the closed position. The gun is now ready to fire. TO DISMANTLE THE FIRING MECHANISM. Take hold of the milled headed locking bolt situated at the lower end of the firing-lock case, pull it to the rear ; at the same time revolve the firing-lock case upward about 45 and pull it gently to the rear. This will remove the case with the firing mechanism complete from the gun. Press the trigger-shaft detent until it disengages from the notch in the firing-lock case. This will allow the trigger-shaft, with its detent, to be withdrawn. Then gently press on the front end of the firing pin, forcing it back into the casing. This will allow the trigger fork to fall out. Then, with one finger placed on the front end of the sear, force it outward; at the same time grasp the front end of the firing pin, which is roughened for the purpose. Give it a sharp pull. This will remove the firing-pin spring and sleeve from the casing. Then place the front end of the firing pin against a block of wood, bear down on the firing-spring sleeve until the spring is com- pressed sufficiently to disengage the slot in the rear end of the sleeve 10261417 3 30 from the small lug on the rear end of the firing pin, slightly turn the sleeve, and then the sleeve can be separated from the spring and pin. By an unscrewing motion the spring can be removed from the pin. The sear can be removed by gently pressing it in toward the center of the casing. To assemble, reverse these operations, taking care that before driv- ing too hard on the end of the trigger shaft that the square hole in the trigger fork is in position to receive the tapered end of the trig- ger shaft. No tools are required for assembling or dismantling this mechanism. TO DISMANTLE THE BREECH MECHANISM. Grasp the operating lever and open the mechanism; when the mechanism is open, force the block latch out of its seat in the block by gently pressing it into its seat in the carrier. Take hold of the block and revolve it to the left until it stops ; then pull it to the rear, taking care not to drop it. The block latch can now be readily re- moved. After the firing-lock case has been removed, the operating lever can be removed by forcing its pivot up from beneath by a gentle pressure from the palm of the hand. The lever latch can be removed by pressing in on the latch at a point near its lower end opposite its pivot; a hole in the latch is cut eccentric with reference to the pivot and a shoulder on the pivot prevents their displace- ment until the latch is forced in until the hole is concentric with the pivot. When this occurs, the pivot can be readily pulled out and the latch removed. To remove the block carrier, force the hinge pin up by hand until it can be caught by the head, and by swinging the carrier back and forth, if the pin sticks, it can readily be re- moved, taking care not to drop the extractor lever. The extractor can now be removed from the gun. Reverse these operations for assembling the mechanism. No tools other than the hands are required for dismantling this breech mechanism. The models of 1902, 1904, and 1905 guns are interchangeable with the model of 1902 carriage. 31 Service ran . . w s~ jp > . %2 o s ! sj a** y Mils. 1.7 3.5 5.4 7.4 9.5 11.6 13.8 16.1 18.6 21.1 23.8 26.5 29.4 32.3 35.4 38.6 41.9 45.3 48.8 52.4 56.1 59.9 63.7 67. 6 71.6 75.6 79.7 83.8 88.0 92.3 96.7 101.2 105.7 110.3 115.1 120.0 124.9 130.0 135.2 140.5 145.8 151.3 156.9 162.5 168.4 174.3 180.3 186.4 192.5 198.8 205.1 211.6 218.1 224. 8 231.5 o *-. a .2 if ll P I I s *o I s p if 55 w O o '" V >5 iSl 3 "S I <5 o k ft I fl 1" fe l-2.fi Percussion, shell and shrapnel. Time shrapnel. h. w. 1. H. L. Yds. Yds. 100 200 300 400 500 000 700 800 900 '" 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800 1,900 2,000 2,100 2,200 2,300 2,400 2,500 2, GOO 2,700 2,800 2,900 3,000 3,100 3,200 3,300 3,400 3,500 3,600 3,700 3,800 3,900 4,000 4,100 4,200 4,300 4,400 4,500 4.600 4.700 4,800 4,900 5,000 5,100 5,200 5,300 5,400 5,500 Yds. 98 192 287 383 480 578 676 775 875 976 1,078 1,180 1,282 1,384 1,487 1,590 1,693 1,796 1,898 2,000 2,101 2,202 2,302 2,401 2,500 2.599 2,698 2,797 2,896 2,995 3,094 3,193 3,292 3,391 3,490 3,500 3,690 3,790 3,890 3,990 4,080 4,190 4,290 4,390 4,490 4,589 4,688 4,787 4, 886 4,985 5,084 5.183 5,282 5,382 5,482 Mils. 0.1 1.8 3.7 5.7 7.8 9.9 12.1 14.5 16.9 19.4 22.1 24.8 27.7 30.6 33.7 36.9 40.2 43.6 47.1 50.7 54.4 58.2 62.0 65.9 69.9 73.9 77.9 82.0 86.2 90.4 94.8 99.3 103.8 108.4 113.2 118.1 123.0 128.1 133.3 138.5 143.9 149.4 154.9 160.6 166.4 172.4 178.4 184.4 190.6 196.9 203.2 209.6 216. 2 222.8 229.5 55.6 52.6 50.0 47.6 47.6 45.5 43.5 40.0 40.0 37.0 37.0 34.5 34.5 32.3 31.3 30.3 29.4 28.6 27.8 27.0 26.3 26.3 25.6 25.0 25.0 24.4 24.4 23.8 23.3 22.7 22.2 22.2 21.7 20.8 20.4 20.4 19.6 19.2 18.9 18.9 18.2 17.9 17.9 16.9 16.9 16.7 16.4 16.4 15.9 15.9 15.6 15.4 14.9 14.9 14.5 Sees. 0.18 .36 .55 .75 .96 1.17 1.38 1.60 1.83 2.07 2.31 2.56 2.81 3.07 3.34 3.61 3.89 4.17 4.46 4.75 5.05 5.35 5.65 5.95 6.26 6.57 6.88 7.19 7.51 7.83 8.15 8.47 8.80 9.13 9.47 9.82 10.17 10.53 10.89 11.25 11.62 11.99 12.37 12.75 13.13 13.52 13.92 14.32 14.72 15.12 15.52 15.92 16.32 16.73 17.14 Mils. 0.0 .2 .3 .4 .4 .5 .6 . 7 .8 .9 .0 .2 .3 .5 :! 2.0 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.4 3.6 3.8 4.0 .2 .6 .8 .0 5.2 5.4 5.7 5.9 6.1 6.4 6.6 6.9 7.2 7.5 7.8 8.1 8.5 8.8 9.2 9.5 9.9 10.2 10.6 10.9 Mils. 0.0 .1 .1 .2 .2 .3 .3 .4 .4 .5 .6 .7 .8 Mils. 1.7 3.6 5.7 8.0 10.5 13.2 16.0 19.1 22.5 26.0 29.7 33.7 37.8 F.S. 1,647.0 1,595.4 1,547.0 1,501.5 1,458.6 1,418.0 1,379.5 1,343.0 1,308.5 1,275.9 1,245.2 1,216.3 1, 189. 2 Yds. 993.2 470.2 297.0 212.2 161.8 129.0 105.8 88.7 75.5 65.3 57.2 50.5 44.8 Yds. Yds. Yds. Yds. 0.08 0.32 8.3 .40 .61 15.9 .9 1.0 .1 .2 .3 .4 .4 1.5 1.6 1.7 1.8 1.9 2.0 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.2 4.3 4.4 .5 .6 .7 .8 .9 42.2 46.7 51.5 56.5 61.7 67.1 72.6 78.4 84.3 90.4 96.6 103.0 109.5 116.1 122.8 129.6 136.6 143.7 151.0 158.4 165.9 173.6 181.5 189.6 197.8 206.2 214.8 223.6 232.5 241.7 250.9 360.4 270.1 279.9 289.9 300.0 310.3 320.8 331.4 342.2 353.1 364.1 1,163.8 1, 140. 1,117.6 1,096.4 1,076.3 1,057.2 1,039.0 1.021.7 1,005.3 989.8 975.2 961.5 948.7 936.7 925.5 915.1 905.5 896.7 888.6 881.1 874.1 867.5 861.2 855.1 849.1 843.1 837.2 831.3 825.5 819.8 814.2 808.7 803.3 798.0 792. 8| 787. 71 782. 7 777. 8 773.0| 768.3 763.81 759.5 40.2 36.3 33.0 30.0 27.5 25.4 23.3 21.7 20.2 18.7 17.5 16.5 15.5 14.5 13.8 13.0 12.3 11.7 11.2 10.7 10.2 9.7 9.2 8.8 8.5 8.2 7.8 7.5 7.2 6.8 6.6 6.3 6.2 5.8 5.7 5.5 5.3 5.2 5.0 4.8 4.7 4.5 1.1 1.2 22.8 2.1 1.5 29.1 2.5 34.5 3.5 1.9 34.6 3.8 37.2 5.3 2.5 39.4 5.3 39.5 7.5 3.0 44.0 7.2 41.9 10.3 3.4 48.2 8.9 44.1 13.6 4.2 52.0 12.2 46.3 17.3 5.4 55.0 15.1 48.3 21.4 6.9 57.4 18.5 50.0 1 This shrapnel was made in accordance with O. O. drawing 75-2-3, the radius of the ogive being 2.93 inches. 32 Service range table for 3-inch field guns Continued. Shrap- nel. Shell. Shell and shrapnel. Probability table, 50 per cent zone. > . . m S- p "i'j S o s5 3 M 1 3 . sj ** L Mils. 238.4 245.4 252.5 259.7 267.1 274.6 282.2 289.9 297.8 305. 7 313.9 322.1 ; 330. 5 339.1 347.7 ; 356. 5 . 365.4 374. 4 383. 6 392. 9 402.3 411.9 I 421. 6 431. 5 ! 441. 5 1 451.6 461.9 472.3 482. 8 493.5 I A > *> ~I 60 3 If P ja f 3 "o s s &* -.9 2 fe cf to 1 I *o f < k ft ll f P c3 10 w III J2 Percussion, shell Time and shrapnel. shrapnel. h. w. 1. H. L. Yds. 5,600 5,700 5,800 5,900 6,000 6,100 6.200 6,300 6,400 6,500 6,600 6,700 f 6,800 6,900 t 7, OOC 7, IOC 7,20C 7,30C 7,40C 7,50( 7,eoc 7,70C 7,80C 7,90C 8, OOC 8, IOC 8,20C 8,30C 8,40C 8,50C Yds. 5,682 5,682 5,781 5,880 8,979 6.078 6,177 6,276 6,375 6,474 6,573 1 6,672 ! 6,771 6,870 6,970 7,070 7,170 7,27C 7.37C 7,47G 7,56S 7,668 7,767 7, 86C | 7,965 8,06-4 8,162 ! 8,265 8,361 | 8,4CC Mils. 236.4 243.3 250.5 257.6 264.9 272.4 280.0 287.7 295.6 303.5 311.6 319. y 328.3 336.8 345.5 354.3 363.2 372.2 381.4 390.7 400.1 409.7 419.4 429.2 439.2 449.3 459.5 469.9 480.4 491.0 14.3 14.1 13.9 13.5 13.3 13.2 13.0 12.7 12.7 12.2 12.2 11.9 11.6 11.6 11.4 11.2 11.1 ! 10.9 1 10.8 10.6 10.4 10.3 10.1 10.0 9.9 9.7 | 9.6 9.5 9.3 9.2 Sees. 17.56 18.00 18.44 18.89 19.36 19.85 20.35 20.86 21.38 21.92 22. 48 23.05 23. C3 24.23 24.85 25.49 2P. 15 2. 83 27.53 28.25 29.00 29.78 30.59 31.42 32.28 33.18 34.12 35.10 36.12 37.18 Mils. 11.3 11.6 11.9 12.2 12.6 12.9 13.3 13.7 14.1 14.5 14.9 15.4 15.8 16.3 16.7 17.2 17.7 18.2 18.7 19.2 19.8 20.3 20.9 21.4 22.0 22.6 23.2 23.8 24.4 25.0 Milt. 5.0 5.1 5.2 5.4 5.5 5.6 5.7 5.8 6.0 6.1 6.3 6.4 6.6 6.7 6.9 *i 7.4 7.6 7.8 8.0 8.2 8.4 8.5 8.7 8.9 9.1 9.3 9.5 9.7 Mils. 375.3 386. 7 398.2 409.8 421.6 433.5 445.6 457.9 470.3 482.8 495.5 508.3 521.3 534.4 547.7 561.1 574.7 1 588.4 C02.3 616.3 630.5 644.9 659 5 F.8. 755.4 751.4 747.5 743.7 740.0 736.4 732.9 729.5 726.2 723.0 719.9 716.9 714.0 711.2 708.5 705.8 703.1 700.4 697.7 695.0 692.3 689.6 G87. Yds. 4.3 4.2 4.0 4.0 3.8 3.7 3.5 3.5 3.3 3.2 3.0 3.0 2.8 2.8 2.7 2.5 2.5 2.3 2.3 2.2 2.0 2.0 2.0 Yds. Yds. Yds. Yds. Yds. 26.0 8.8 59.2 22.7 51.7 31.2 11.2 61. 28. 1 53.4 37.3 14.0 62. 3 34. 4 55.1 44.4 17.4 63. 6 43. 5 56.6 i 674.2 689.0 704.0 719. 2 734.6 ! 750. 2 766.0 C84.5; 1.8 682. 1.8 679. 5 1. 8 677. 0, 1. 7 674. 5 1.7 672. 1. 5 669. 5 1. 5 53.0 21.3 64. 7 52. 6 57.8 NOTE. One "mil"= TT 1 ir5 of a quadrant. This corresponds to the graduation of the battery commander's telescope and the deviation scales on the panoramic and open sights, and equals, for variations in height or lateral deviation, approximately T^TT of the range. PORT MONROE, VA., Sept. 23, 1904. Variations in muzzle velocity to be expected at various tempera- tures of the powder: Temperature. M. V. F. S. 30 F. -48 40 -40 50 -31 CO -19 70 80 + 24 90 + 52 100 + 82 33 Complete range table for 8-inch field guns, models of 1902, 190Jj, and 1905, irlicn fired with shrapnel. [M. V.= 1,700 f.s.] i i .9 . " 1 '^ o . d a . 5S -H II il g! 1 o , 2 M A 8 i 3 K sl jjj < il ; -3 i < 5 "3 > P 03 be q I H H ^1 "Ig T3b ' ft d i 1 9 CH "3 ^ 1* o 1 1 E t> 'a s| 1 +3 ft a ,1 fl ^ *T o M *i 3 o d || "o o 1 "o 1 "o S rt 05 ^ 3 o < - Q> Q) 43 point i's brought opposite the line on the flange of the high explosive head, the vent g 2 is covered by the solid metal between the ends of the upper train and the channel u' leading to the base charge is covered by the solid metal between the ends of the lower or movable time train. At the safety setting it may be seen that the upper train may burn entirely out in case of accidental firing of the time plunger or in case it may be desired to burst the shrapnel by impact or per- cussion, without the flame being able to reach the base charge. The felt washers / and h are glued to the upper face of the grad- uated time-train ring and to the upper face of the flange on the high explosive head. These surfaces are corrugated, as shown, to make the washers adhere more strongly. The function of the wash- ers is to make a gas check and prevent premature action of the fuzes. To release the pressure of the gases due to the burning train a vent hole is drilled into the upper and lower time-train ring leading from the end of the train to the outside. These holes are sealed by alumi- num disks, but the pressure due to the burning trains immediately opens them. These fuzes are issued assembled in shrapnel. For transportation in limbers and caissons the fuze should always be set at the safety point. The fuze is provided with a waterproof hood of thin brass her- metically sealed. The hood must be stripped off before setting the fuze, but should not be moved until the shrapnel is about to be fired. FRANKFORD ARSENAL COMBINATION FUZE, MODEL, OF 1907 M. [Plate VI.] This fuze consists of the following parts, assembled as shown in the drawing : a. Body, bronze. a,'. Stop pin, brass. &. Closing cap, brass. &'. Vents in closing cap. c. Upper time-train ring, Tobin bronze. c'. Washer for time-train ring, gradu- ated, felt cloth. d. Time-train ring, graduated, Tobin bronze. d'. Washer for body, felt cloth. d 2 . Rotating pin, brass. e. Concussion plunger. e'. Concussion resistance ring, brass. /. Firing pin, brass. g. Vent leading to upper time train. h. Compressed powder pellet. i. Upper time train, compressed pow- der. ;'. Compressed powder pellet, in vent leading to lower time train. ;'. Compressed powder pellet in lower time-train vent. fc. Lower time train, compressed pow- der. I. Brass disk, crimped in place. m. Compressed powder pellet in vent c. o. Vent leading to magazine. p. Powder magazine. q. Percussion plunger. r. Percussion primer. s. Vents leading from percussion primer to magazine. u. Bottom closing screw, brass. v. Washer for closing screw, muslin. w. Washer for closing screw, brass. 44 The body a of this fuze is machined from a bronze casting. The time-train rings c and d are turned from hard-rolled rods of Tobin bronze. An annular groove in the shape of a horseshoe is milled in the lower face of each of the time-train rings. Meal powder is com- pressed into these grooves under a pressure of 66,000 pounds per square inch, forming a time train, the total length of which is 9 inches. The time element of this fuze is composed principally of the fol- lowing parts: The time or concussion plunger 0, the concussion re- sistance ring e' ', the firing pin /, the vent ----- f/amplny Solts and Mu Hand Fuze Setter. Range Ring \-Base -Rotating Pin Notch. - .RangeRingCarrier 53 The corrector scale is graduated into 60 equal divisions and is numbered each 10 divisions. It is used to vary the height of burst of shrapnel and to compensate errors made in determining the angle of sight and variations in the rate of burning of the time train of the fuze. In use the battery commander indicates the corrector reading desired. The division corresponding to 30 is the middle of the scale and indicates the normal height of burst of 3 mils under normal conditions. Should it be desired to increase the height of burst an increased corrector scale reading is required, and for a lower burst a decreased reading is required. It should be noted that an increased corrector reading corresponds to a decreased range and a decreased corrector reading corresponds to an increased range. THE BRACKET FUZE. SETTER, MODEL OF 1905 M. The bracket fuze setter is attached to the rear end of the fuze-setter bracket on the caisson. It consists of the following principal parts: Base, housing, corrector-worm case, guide, and range and corrector worms, rings, and scales. The base is attached to the fuze-setter bracket by four bolts. The housing, the corrector- worm case, and the guide are each secured to the base by screws. These are the fixed parts of the instrument. The housing forms a cover for the movable parts and affords a seat for the range worm. In the corrector-worm case are formed bearings for the corrector worm. The corrector ring and the range-ring worm wheel (which carries the range ring) are the movable parts of the fuze setter. When assembled, the interior surfaces of these two rings, in connection with the bore of the fuze-setter base, form a socket, shaped to fit the exterior of the combination fuzes. Upon a portion of the exterior of the corrector ring is formed a segment of a worm wheel meshing with the worm seated in a fixed part of the instrument (the corrector- worm case), so that turning the worm rotates the corrector ring. A notch is cut in the inner surface of the corrector ring to take the rotating pin, which projects from the graduated time-train ring of the fuze. The pointer arm attached to the corrector ring carries at its upper end flush with the upper surface of the fuze setter the pointer plate which is an index for the corrector scale. Suitable manipulation of the corrector worm moves the cor- rector ring until the index is set at any desired division of the scale. The range-ring worm wheel is located within the housing and is mounted on the corrector- worm case and ring, and the worm wheel formed on its exterior surface meshes with the range worm, seated in bearings in the housing. The range ring is attached by four screws to the upper surface of the range-ring worm wheel and located by a 10261417 5 54 pin. This ring may therefore be set at any desired reading by suit- able manipulation of the range worm. Some of the earlier bracket fuze setters of model 1905 are provided with two corrector scales, one for "Ehrhardt" and the other for " F. A. and Krupp " fuzes, each plainly marked. The outer or Ehrhardt corrector scale is no longer used and is being removed when fuze setters are turned in for repairs. The inner or F. A. and Krupp scale is attached by screws to the housing and is used with ammuni- tion having F. A. fuzes, models of 1907 and 1907 M and Ehrhardt fuzes, 1911. The range ring is set for a given range when the division indicating that range is in line with the range-scale index, which is the central divison on the corrector scale (not the corrector index). The cor- rector scale is set for a given correction when the corrector index (which is movable) is opposite the specified division of the corrector scale. When on the range ring is set opposite the range-scale index, which is engraved on the corrector scale, and the pointer-arm index is opposite 30 on the corrector scale, the fuze will be set at 0. When setting a fuze to explode on impact or for safe transportation the " S " on the range ring should be set opposite the range-scale index and the pointer-arm index set opposite 30 on the corrector scale. Great care should be exercised in making this setting. To use the bracket fuze setter, set the range ring and corrector scale at the range and correction ordered by turning their respective worms ; remove the weatherproof cover on the fuze by ripping off the soldering strip ; place the point of the projectile in the fuze setter with the rotating pin of the graduated time-train ring engaging its notch in the corrector ring; hold the projectile against the guide, and while pressing the fuze firmly into the fuze-setter socket turn the projectile in a clockwise direction until the stop brings up against the side of the fixed stop pin in the body. Especial care must be taken to always rotate the projectile in a clockwise direction. When not in use it should be secured in its traveling position and protected by the fuze-setter cover issued for this purpose. The earlier models of both bracket and hand fuze setters were fitted with a spring plunger to engage with a notch in the body of the fuze in order to limit the setting of the fuze. In the model of 1905 M the spring plunger has been replaced by a fixed stop. The range worm, range-ring worm wheel, corrector worm, and cor- rector ring should be removed from time to time and thoroughly cleaned and oiled. To disassemble, remove the taper pin from the crank and the crank from the range worm; withdraw the worm. Unscrew the four housing screws and remove the housing and the range-ring worm wheel. Drive out the taper pin from the corrector- 55 worm knob ; remove the knob from the corrector worm and withdraw the corrector worm. Unscrew the worm-case screws, and remove the corrector-worm case. Remove the corrector ring from base. Clean thoroughly, grease the worms and the gears, oil the bearings for worms, and assemble in reverse order. THE HAND FUZE SETTER, MODEL. OF 1905 M. The hand fuze setter is provided for the same purpose as the bracket fuze setter, and is intended to supplement the latter. One hand fuze setter is issued in a leather case and is carried in the trail box of each gun. It is intended for use in case the bracket fuze setter should become disabled, or in case the gun should for any reason be separated from its caissons. The names of the parts of the hand fuze setter and the manner in which they are assembled are shown in Plate VIII. The corrector scale of the hand fuze setter is for the same purpose as that of the bracket fuze setter, but, unlike the latter, is incapable of adjustment independently of the range ring. In use, the range and correction having been ordered, the graduation line correspond- ing to the designated range is set opposite the graduation line cor- responding to the designated correction. A new design of corrector scale with sliding index has been adopted and will be issued to replace all of the old design. In use, the range and corrector setting having been ordered, the sliding index is set at the designated corrector setting and the graduation line correspond- ing to the range is set opposite the fiducial edge of the index. This will require that whenever the corrector or range is changed the fuze setter must be undamped and a new setting made. To use the hand fuze setter, loosen the clamp screw, set the range ring at the range and correction ordered, and clamp; remove the waterproof cover of the fuze ; place the fuze setter over the point of the projectile and turn in a clockwise direction until the rotating pin of the graduating time-train ring engages in the notch provided for it ; then press firmly down on the fuze setter and continue to turn in a clockwise direction until the stop pin in the fuze setter engages with the fixed stop pin in fuze body and prevents further rotation. Especial care must be taken to rotate the fuze setter in a clockwise direction. The hand fuze setter should be disassembled from time to time and thoroughly cleaned and oiled. To disassemble : Remove the corrector- scale mechanism, unscrew the clamp screw, remove the clamp shoe. Remove plug, unscrew the base from the case, withdraw the range- ring carrier with range ring and handle from the case. Clean thor- oughly, oil, and assemble in reverse order. To turn over the range ring it is necessary to remove the handle from the range-ring carrier 56 by removing the six handle screws and then remove the four range- ring screws. The corrector scale with the sliding index must not be removed from the scale, as small parts may be lost and difficulty will be experienced in reassembling. HAND FUZE SETTER, MODEL OF 1912. The hand fuze setter is a device for rapid and accurate setting of the fuze for various ranges and heights of burst. Plate VIII shows assembled and sectional views and designation of parts. The prin- cipal parts are the case, the range-index mechanism, range mecha- nism, correction mechanism, and guide plate. The case forms a housing for the movable parts and provides seats for the worm cases and the index bar. The slot, cut in the top of the case, limits the movement of the projecting segment of the corrector- scale support which carries the corrector scale. The serrated rim forms a handle for turning. The arrow engraved upon the top and lower center edge of the case coincides with the graduations of the corrector scale. Two oil-hole screws are located in the case directly under the serrated rim on both right and left sides and identified by the word " Oil." The range-index mechanism consists principally of the index bar, range index, index plunger, and index spring. The index bar is retained in its seat, located in the case directly above the range-ring corrector-scale screws. On this scale is graduated 120 equal divisions, 50 minutes apart, numbered every 10 divisions. Graduation num- bered 30 is the normal or zero position and is indicated by an arrow. The word " Turn " and an arrow engraved upon the corrector scale indicates the direction the fuze setter must be turned when setting a fuze. A pointer is riveted and soldered to the top of the corrector scale in a certain position to coincide with the graduated line on the closing cap of the fuze. The range-ring carrier is seated in the corrector-scale support. The worm teeth mesh with the threads of the worm on the right side of the fuze setter. The slot, which is cut in the bottom side of the range-ring carrier, engages with the rotating pin in the graduated time-train ring of the fuze. The interior is conical in shape to suit the exterior of the fuze. The corrector-scale support is held within the case by the guide plate. The worm teeth mesh with the threads of the worm on the left side of the fuze setter. The movement of the corrector-scale support is limited in both directions by the slot in the case. The stop pin is secured in the interior of the corrector-scale support by the stop-pin screw and engages with the fixed stop pin in the body of the fuze to limit the movement of the fuze setter. 57 The worms are mounted eccentrically in the worm cases which when turned provide an adjustment to take up the wear between the worm teeth of the range-ring carrier or corrector-scale support and the threads of their respective worm. The worm cases have screw- driver slots at their rear ends, which are provided for adjusting and are locked in position by the worm-case clamp plugs, which are secured by the worm-case clamp screws. The worm-adjusting screws have fiber washers fitted in their ends that bear upon the collars of the worms for taking up end motion and to provide sufficient fric- tion to resist accidental turning. A screw-driver slot is located at their front end for adjusting. The worm-adjusting screws are locked in position by the worm-adjusting screw clamp plugs which are secured by the worm-adjusting screw clamp screws. The worm knobs are secured to the worms by taper pins. The exterior of the worm knobs is straight knurled to facilitate turning. The guide plate is screwed in its threaded seat in the bottom of the case and retained in position by the guide-plate lock screw. DISASSEMBLING AND ASSEMBLING. To disassemble remove the index-bar mechanism, which is held in place by two index-bar screws. Take out the three range-ring screws and the two corrector-scale screws and remove the range ring and the corrector scale. Remove the guide-plate lock screw and unscrew the guide plate, using a teat wrench. To remove the worm knobs from the worms drive out the taper pins. Loosen the worm-adjusting screw clamp screws which release the worm-adjust- ing screw clamp by two index-bar screws and forms a slide for the range index. The V-shaped notches in the index bar are marked with numbers 1, 2, and 3 with the word " zone," which agree with the zones of the range ring. The range index sliding upon the index bar is held in position by the index spring forcing the index plunger into the V-shaped notches of the index bar. The range mechanism consists principally of the range ring, range-ring carrier, worm, worm case, worm-adjusting screw, and worm knob. The correction mechanism consists principally of the corrector scale, corrector-scale support, worm, worm case, worm- ad justing screw, and worm knob. The range ring is located upon the range-ring carrier by a steel dowel pin and secured in position by three range-ring screws. The outer zone or zone 3 is graduated for the " 21-second fuze " and the middle zone or zone 2 is graduated for the " Ehrhardt fuze, 1911." Both scales are graduated for ranges of 6,400 yards ; least division is 50 yards and numbered every 500 yards. The data for graduating 58 the range ring is computed from actual corrected firings and then cor- rected for a suitable height of burst of 3 mils. The graduated surface is sand blasted and lacquered. The corrector scale is mounted upon the projected segment of the corrector-scale support and secured by two plugs. Remove the worm-adjusting screws. The worms can now be removed by turn- ing. The corector-scale support and range-ring carrier can then be removed. To remove the worm cases, loosen the worm-case clamp screws, which release the worm-case clamp plugs. Assemble in reverse order. ADJUSTMENT. Backlash or lost motion may appear between the collars of the worms and the fiber washers endwise; between the worm teeth of the range-ring carriers or the corrector-scale support and the threads of their respective worms. To remove the end backlash, loosen the worm-adjusting screw clamp screw, which releases the worm-adjusting screw clamp plug; then turn the worm-adjusting screws clockwise, using a screw driver, until the end play is removed and there is sufficient friction to prevent accidental turning of the worms. The worm- ad justing screw clamp plugs must be firmly clamped after adjusting, by tightening the worm-adjusting clamp screws, which secures the worm- ad justing screws against rotation. Should backlash appear between the worm teeth of the range- ring carrier or the corrector-scale support and the threads of their respective worms, it can readily be removed by loosening the worm- case clamp screws, which release the worm-case clamp plugs, and then turning the worm cases, using a screw driver in a slot at the rear end, in which the worms are eccentrically mounted, so as to bring the worms in closer contact with the worm teeth. The worm- case clamp plugs must be firmly clamped after adjusting by tighten- ing the worm-case clamp screws which secure the worm cases against rotation. OPERATION. First. Set the range index on the index bar to correspond with the fuze to be used. Second. Turn the worm knob, pinned to the worm and located at the front-right side of the fuze setter, until the desired range on the range ring registers with the range index. Third. Turn the worm knob, pinned to the worm and located at the front-left side of the fuze setter, until the graduated line on the corrector scale, which indicates the desired correction for height of burst, registers with the engraved arrow on the case. 59 The graduation, numbered 30 and indicated by an arrowhead, is the normal height of burst under normal conditions. A decreased reading on the corrector scale decreases the height of burst and increases the range, and increased reading increases the height of burst and shortens the range. To set a fuze, remove the waterproof cover, place the fuze setter over the fuze and turn until the slot in the bottom of the range-ring carrier engages with the rotating pin in the graduated time train ring of the fuze. The guide plate and conical interior of the range- ring carrier will then rest upon the fuze. Turn the fuze setter clockwise, as indicated by the arrow on the corrector scale until the stop pin fastened to the corrector-scale support engages with the fixed stop pin in the body of the fuze and further motion is prevented. The pointer, which is attached to the top of the corrector scale, should register with the gradual line on the closing cap, to indicate that the stop pin of the fuze setter and the fixed-stop pin of the fuze are in contact. This pointer is added, as the graduated time train ring of the fuze has tendency to stick or to bind to such a degree as to indicate that the stop pin of the fuze setter and the fixed-stop pin of the fuze are in contact. Cards for recording the results of tests of the fuze setters are fur- nished by the Ordnance Department for each size of gun, howitzer, or mortar, on which computed problems of inspection are given as indicated below. The examples given below are for 3-inch field gun. The cards for other calibers are similar. Range ring. Corrector scale. Computed settings. Fuze settings. 21-sec. fuze. Ehrhardt fuze, 1911. 21-sec. fuze. Ehrhardt fuze, 1911. .2,000 3,750 5,500 30 4 45 30 5.99 9.22 16.95 5.71 8.92 16.76 To check the fuze setter, set the range ring and corrector scale to that tabular readings. Set the fuze with the fuze setter and com- pare the results with the computed setting in the table. Use shrap- nel and not a drill cartridge in making this test. When the range index registers with on the range ring and the corrector scale at 30, the fuze is set at 0, and will explode immediately on leaving the gun. When setting a fuze to explode on impact, set the range index at S and the corrector scale at 30. CAEE AND PEESEEVATION. The interior of the fuze setter can be oiled by removing the oil- hole screws ; the locations are identified by the word " oil." 60 THE 3-INCH GUN CARRIAGE, MODEL OF 1902. Weight of carriage, complete, with 4 rounds of ammunition, weighing 75 pounds pounds 1,685 Weight of gun and carriage, complete do 2, 520 Weight at end of trail, carriage limbered do 115 Diameter of wheels inches 56 Width of track do 60 Length of recoil of gun on carriage do 45 Height of axis of gun do 40. 875 Height of line of peep sight do 44. 9 Length of peep-sight radius , do 36. 75 Maximum angle of elevation degrees 15 Maximum angle of depression ^_do 5 Amount of traverse of gun on carriage mils 140 Rounds of ammunition carried on carriage 4 NOMENCLATURE OF PARTS OF CARRIAGE. No. 1 1 2 2 2 4 1 1 1 2 2 8 1 1 1 1 1 1 1 1 Name of part. Location, etc. Property clas- sification. Class. Section. Axle IV 3 Trail, consisting rf Flasks (right and left) i Form ricrht and loft Qirlo nf trail Axle bearings (right and left) . . . Riveted to front end of flasks, right and left. One in each axle bearing Bushings (axle bearing) Bolts for axle bearing Clamp bearing to axle Elevating-gear transom Riveted between flasks Consisting of Transom, front Forms front of elevating- gear transom. Forms rear of elevating- gear transom. . Between front and rear transoms One riveted to each middle transom... Hold middle transom in place Transom, rear Transoms, middle . Transom bearings Bolts for elevating-gear transom Tool box Riveted between flasks Consisting of Tool-box transom, front ...do.... Tool-box transom, rear . do Tool-box bottom Tool box in trail Tool-box top plate Riveted to top of flasks and tool-box transom, front. Forms top of tool box Tool-box cover, with 2 hinges and 2 pins. Tool-box fastening Fastened to lid and rear transom At rear end of tool-box lid... Consisting of Handle.... Eyes li Clips . Guides ............................ Stop .............................. Rear-sight box cover ................. . Rear-sight box projection .......... Catch ................................ . Rear-sight box cover hinges and 2 pins Rear-sight box bottom ............... , Lock-chain rivet, with chain ......... Lock eve ............................. Rear-sight packing, No. 1 ............ Rear-sight packing A ................. , Rear-sight packing B ................. Wheel-guard transom ........ Rear-sight box and trail top plate . . . Spade Spade edge Spade brace Spade point Crosstie Riveted to tool-box transom, rear Riveted to tool-box lid do.... .do. Forms top of rear-sight box .......... Riveted to rear-sight box bottom ..... Riveted to rear-sight box cover ....... Riveted to cover ..................... Forms bottom of rear-sight box ...... Riveted to left flask .................. Riveted to rear-sight box cover ....... Fastened to rear-sight box bottom ____ Riveted to rear-sight box cover ....... ...do... Riveted between flasks at rear end of rear-sight box. Riveted to top of flasks Riveted to ends of flasks Riveted to face of spade , Riveted to spade Riveted to spade brace , Riveted between trail flasks at spade end. 61 NOMENCLATURE OF PARTS OF CARRIAGE Continued. No. Name of part. Location, etc. Property clas- sification. Class. ectiou. 1 1 1 1 1 1 1 2 1 1 2 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 2 1 1 1 1 1 1 2 1 1 1 2 2 1 1 1 1 Trail, consisting of Cpntinued. "RivfttArl t.n snadfi IV 3 Filler (for lunette bracket) PirmAri tr flnat Handspike fulcrum Riveted on lunette bracket, spade, and float. Riveted between lunette bracket and trail. Riveted to trail cover plate Lunette bracket reinforce . Wheel guards, 1 right, 1 left Riveted to flasks and wheel-guard transom. Riveted on float and spade Trail handle (right) Trail handle (left) do Trail seats Riveted to seat supports do Elevating and traversing lock, consisting of Bolt Fastens hinge to elevating gear transom Riveted to elevating-gear transom,rear. Pinned to hinge Hinge Hook Hook center. .. Pinned to hook Pin Connects hinge, hook, and hook center. iSk Joins spring and hook Link pins Pinned in link Lug Riveted to cradle Sponge-staff socket Riveted to right flask do Consisting of Hasp On sponge fastening. . Bolt ....do Attached to bolt Pin On sponge fastening Name plate Riveted to tool-box hinge plate Handspike On handspike fulcrum Handspike bolt Secures handspike to fulcrum In lunette bracket Padlock Fastened to chain on left flask do Cradle, consisting of Cradle body Below gun Cradle head, rear (carriages Nos. 1 to 168). Cradle head, rear (for carriages 169 and up). Cradle top plate Riveted on body do Riveted on top of body Gun slide (right) Riveted on body and cover plate do Gun slide (left) Felt washer In cradle head rear Riveted on bottom of body Oil tubes Riveted on bottom of body . . do Bracket seat, firing handle Hiveted on right side (carriages Nos. 1 to 168). Riveted on right side do Shoulder-guard fastenings, 1 front, 1 rear. Riveted on left side do Clip filler piece Riveted on left side Shoulder-guard brace Secures shoulder guard to cradle Riveted on left side Rear-sight bracket support do Retaining-ring bolt fastenings Riveted inside cradle Spring-support guide (left) do Retaining ring with hasp In bolt fastening do Cradle head front Consisting of Bushing In front cradle head Handle for cradle head Hasp eye . . . ...do... 62 NOMENCLATURE OF PARTS OF CARRIAGE Continued. Name of part. Location, etc. Property clas- sification. Class. Section. 1 Shoulder guard 1 Shoulder-guard pin : Dust guard, with 4 spring covers and 2 re- coil-indicator throw hinges. On rear end of cradle Secures shoulder guard to cradle 4J for model of 1902: 89J for model of 1305, and 90G for model of 1904 guns. On cradle guide rails. Cradle brush Riveted to dust guard Consisting of Brush plate ! Part of cradle brush Rear felt plate ' do Front felt plate do Recoil indicator In indicator guide Consisting of Guide Riveted to cradle Spring ! Slide.. Washers Pointer Recoil-indicator throw Attached to dust guard by recoil-indi- cator throw hinge. Recoil-indicator throw hinges ! Attached to dust guard Firing shaft In firing-shaft bearing (carriages Nos. 1 to 168). Firing-shaft bearing Riveted to right side of cradle Firing handle, with spring and plunger. . . On firing shaft (carriages Nos. 1 to 168). Firing mechanism ' For carriages after No. 168 Consisting of Firing-handle bracket seat Riveted on right side of cradle Firing-handle bracket Assembled on bracket seat Adjusting screw ! Assembled in bracket Adjusting-screw check nut ! Assembled on screw Shaft trip collar Assembled on firing shaft Firing-handle hub ' Assembled on shaft in bracket Firing handle ' Assembled onhub with Stop ; Fastened to rear cradle head Plug Assembled with handle Plunger : do IV Spring do Pin do Bracket studs and nuts Riveted on cradle Shaft return spring Rear end of bracket Handle return spring Front end of bracket Trip collar pin Secures trip collar to shaft Trip latch Attached to trip latch plunger Trip latch pin Secures trip latch to plunger Trip latch spring Assembled in firing-handle hub Firing shaft Assembled in bracket Trip latch plunger Assembled in firing-handle hub Cylinder with cylinder end screwed in In cradle Cylinder end washer Fits in cylinder end Cylinder end stud Connects cylinder to gun Cylinder end stud nut ! On cylinder end stud Screw for cylinder end | Prevents cylinder end unscrewing Counter-recoil buffer Screwed and pinned on cylinder end stud. Cylinder head with 3 screw eyes j Front end of cylinder Cylinder head washer In cylinder head Gland | Screwed on head Lashing wire I Lashes, gland, cylinder head and plug together. Rings, packing Garlock hydraulic waterproof pack- ing. 0.25 inch square. Piston rod, with plug, screwed in In cylinder Piston At rear end of piston rod Piston-rod nut At front end of piston rod Filling plug with gasket Screwed in end of piston rod Drain plug Screwed into cylinder head Drain plug gasket Fits in cylinder head Spring support In cradle on cylinder Counter-recoil springs do Outer counter recoil springs do Inner counter recoil springs do Separators Used between inner and outer recoil springs. 1 On repaired carriages this is part of the cradle head, rear. 2 Issued in place of the flat counter recoil springs. 63 NOMENCLATURE OF PARTS OF CARRIAGE Continued. Name of part. Location, etc. Property clas- sification. Class. Section. Rocker, complete Consisting of Angle Pintle socket with bushings and spring covers. Traversing-gear case Traversing plate Traversing-plate liner Azimuth scale with filler piece Traversing mechanism, complete Consisting of Hand wheel with handle and spindle. Traversing shaft Nut Bushing Traversing-shaf t bearing, outer Cap On axle between flasks. Riveted to rocker angle . .do. .do. .do. .do. In gear case on rocker. Bearing locking pin with spring Traversing-shaft adjusting nut Traversing-shaf t bearing Taper pins Traversing link with bushing, spring cover, and plate for closing groove. Traversing-link pivot with nut : Azimuth pointer Azimuth-pointer screws Elevating mechanism, consisting of Elevating pin Inner elevating screw , On end of shaft In bearings in gear case Mounted on shaft In right end of case Riveted on left side of trail Attached to traversing shaft bearing, outer. Fits in traversing shaft bearing, outer. Mounted on shaft In left end of case Hold traversing shaft bearing in place . Between case and cradle In traversing lug on cradle Attached to rear clip by screws. Outer elevating screw. Elevating gear bracket, with 4 bush- ings and 2 handy oilers. Elevating bevel gear Keys Elevating bevel pinions Elevating bevel pinion taper pins Elevating crank shafts, with handles and washer. Elevating screw cover Consisting of Large disk Intermediate disk Small disk Body Axle seats, complete, include Secures inner screw to rocker Between rocker and outer elevating screw. Between inner ele vating screw and ele- vating gear bracket. On bearing in trail transoms In elevating gear bracket. Riveted in bevel gear Mounted on shafts Secures pinions to shaft. . In elevating gear bracket. Lower end of bracket IV Bracket fastenings (right) . Bracket fastenings (left). Bracket fastening and segment bracket Seat (right) Seat (left) Seat supports Special bolts and nuts Special bolt pin Seat arm (right) Seat arm (left) Seat-arm bracket (right) Seat-arm bracket (left) Seat-arm guard (right) Seat-arm guard (left). Clamped on each end of axle do Clamp brackets on axle Seat-arm support, (right) Seat-arm support, (left) Shield-brace bolts, with nuts. 2 I Ammunition carriers (right and left) Consisting of Brake bracket tube (right) Brake bracket tube (left) Faceplates Tube-support plates Plate angle Tube heads (right) E-'ube heads (left) Form braces under seat For seat supports Attach supports to special bolts . Riveted to seat-arm bracket .do. Riveted to right seat Riveted to left seat Riveted to right seat arm and shield brace. Riveted to left seat arm and shield brace. Supports seat arm on rear .do. Through shield brace, seat arm, seat- arm support, and shield-brace clip. Bolted to bracket fastening Attached to axle by tube support plates and bracket fastenings. Bolted to bracket fastening Riveted to rear end of tube Riveted to tube support plate do ...do... For new work and repair. 64 NOMENCLATURE OF PARTS OF CARRIAGE Continued. Name of part. Location, etc. Property clas- sification. Class. iSection. Ammunition carriers (right and left) Con. Consisting of Continued. Tie-rod fastenings, with nuts Riveted to side of tube Filler rings (upper and lower) \ Inside tubes Reinforce rings do Filler pieces ', Between tube heads Apron-latch brackets j One riveted to each pair of tubes Apron-latch bracket reinforce Inside of tubes Brake-beam tubes Connects front end of each pair of tubes Brake-beam guide | In brake-beam tubes Brake-beam fulcrum j do Foot rests Front end of tubes Foot-rest braces do Tie rods Brace tubes from bracket fastening Tie-rod washers On tie-rod fastenings Tie-rod pins Through bracket fastenings Shield braces Brace tubes from shield Covers, tube, with hinge pins | Hinged to tubes Cover latches, tube, with pins j Secure covers Cover-latch springs, tube Road brake, complete, includes Brake beams I Seated in brake beams tubes Brake shoes End of brake beams Brake-shoe tap bolts Secure shoes to beams Fulcrum pins Pivots for beams Brake-rod ends On end of beams Brake rods Between brake-rod end and spring Springs Inside of spring cover Spring covers Between spring-cover head and spring- cover end. Spring-cover heads .' Slide on brake rod Spring-cover ends Connect spring covers with brake crank and lever. Brake-rod pins Through beams and cranks , Crank On end of brake shaft Brake lever do Brake-lever catch On lever Lever hook On brake lever Brake shaft In bearing, near axle Bushings In brake-shaft bearings IV Segment bracket Clamped on axle ' Segment-bracket bolt, with nut Brake segment with two segment racks Riveted to segment bracket Apron latches, complete, include Apron-latch blocks Bolted to apron-latch bracket, which is riveted to the ammunition tubes. Apron-latch bolts and nuts ! Secure block to bracket Apror -latch pins j Form pivot for apron-latch body Apron-latch bodies Pivoted on block ." Apron-latch levers Pivoted on bodies Apron-latch lever pins Apron-latch plungers Seated in body Plunger eyes Screwed on end of plunger Plunger-eye pins Attach plunger eye to lever Apron-latch springs In body around plunger Apron-latch bushings Screwed into body Apron shield, consisting of Apron Hinged to bracket fastening Apron hinges Riveted to apron Apron-hinge pins Through apron hinges and bracket fastenings. Apron-hinge fillers, used with 0.15: Riveted to apron armor plate. Apron-latch staples ! do Main shield, complete, consisting of Main shield Bolted to bracket fastenings and axle bearings. Hood Riveted to main shield Hood angle Riveted to hood Shutter, peep-sight port Hinged to shield , Shutter, panoramic-sight port do Shutter support Riveted to shutter Shutter-latch base do 1 Shutter-latch plunger In shutter-latch base Shutter-latch spring do 6 Hinge, sight port shutter On shield 1 Hinge pin, sight port shutter In hinges 2 j Filler, shutter hinge Between hinge and shield 65 NOMENCLATURE OF PARTS OF CARRIAGE Continued. No. Name of part. Main shield, complete, consisting of Continued. Wing nuts (front ) Wing nuts (rear) Wing-nut pins (front) Wing-nut pins (rear) Wing-nut pin washers Bracket-fastening fillers Shield-brace clip (right) Shield-brace clip (left) Top shield center hinge (lower half) . Top shield outer hinge (lower half) right. Top shield outer hinge (lower half ), left . Washers for shield bolts Bolts, 1.265 grip, with nuts Bolts, 0.92 grip, with nuts. Bolts, 1.05 grip, with nuts Bolts, 0.64 grip Top shield, complete, consisting of Top shield Top shield center hinge (upper half)... Top shield outer hinge (upper half), right. Top shield outer hinge (upper half), left. Location, etc. Riveted on shield .do. Riveted to shield ....do On pins Bolted in bracket fastening with shield. Riveted to shield ....do ...do... Property clas- sification. Class. Section. .do. .do. Through shield, ammunition carriers, bracket fastenings, and washers. Through shield, bracket, seat, ammu- nition carriers, and washers. Through shield, bracket, seat, ammu- nition carriers, seat-arm support, and washers. Through axle bearings, shield, and washers. Hinged to main shield . Riveted to top shield . ...do... .do. 1 Top shield center hinge pin . 2 Top shield outer hinge pins . Top shield fastenings. Fastening hinges Fastening-hinge pins Range quadrant case bracket, consisting of Bracket Connects parts of hinges. . . ....do Pivoted to fastening hinge . Riveted to top shield Right spring support Left spring support Range quadrant case, complete, consisting of Lid... Bolted on rear face of main shield, right side. Riveted to bracket ...do... Body Bottom Box support, left Box support, right Bearing plate, left (upper and lower) . . Bearing plate, upper, right Bearing plate, lower, right Case hinges (upper half) Case hinges (lower half) Hinge pins Hasp hinge Hasp Wing nut Wing-nut pin and washer Wing-nut pin reinforce Chain eye Padlocks chain Leather-covered packing blocks *-inch button head bolts with nuts Washers Bolts with nuts 0.375 pipes Springs, quadrant case Padlock Bolt snap Panoramic sight case bracket, complete, ! consisting of Bracket, sight case Swung between springs by box sup- ports, in bracket. do ...do... Riveted on case do Riveted to left box support . . Riveted to right box support. do Riveted on lid Riveted to back of case Riveted on case lid.. . Riveted on case front . Riveted on case . . . .do. .do. .do. Attached to chain eye Screwed to inside of case Bolt bracket to seat Go with bolts Secure case to bracket On bolts Not interchangeable with sight-case springs. Fastened to quadrant case do Spring support (right) . Spring support (left) . . Bolted on rear face of main shield, left side. Riveted to bracket . . .do IV 66 NOMENCLATURE OF PARTS OF CARRIAGE Continued. No. Name of part. Location, etc. Proper siflcs ty clas- ition. Class. Section, 1 1 Panoramic sight case, complete, consisting of Lid Suspended between springs in bracket . 1 Body .do . . 1 Bottom do B ox -supports Riveted to case 2 Riveted to spring supports ? .do . .. 2 Riveted on case lid 9 Case lunges lower half Riveted to back of case 3 1 Hast) hinge Riveted on case lid 1 Hasp Riveted on case front 1 Wing nut Riveted on case 1 Wing-nut pin and washer do 1 Wing-nut pin reinforce do . 1 do 1 Padlock chain Attached to chain eye 5 Leather-covered wood packing blocks Screwed to inside of case 9 i-inch button head bolts with nuts Bolts bracket to shield 2 Washers Go with nuts 4 Bolts with nuts Secure case to bracket 4 375 pipes On bolts 8 Springs sight case . . Not interchangeable with quadrant- 1 Padlock case springs. Fastened to panoramic sight case 1 Bolt snap do 1 1 Front sight, complete, consisting of Front-siht bracket Rests in socket riveted to cradle ... 1 Sleeve Threaded to bracket 1 Holder Supports ring with cross wires 1 1 1 Rear sight, complete, consisting of Rear-sight bracket with shank socket. . Rear-sight shank Fastened by two nuts to bracket sup- port riveted to cradle. Constitutes the "rear" sight > IV 3 1 Shank-socket cover 1 Fitted to rear sight shank 1 2 16 Wheels, 56-inch, complete, consisting of 8 64 i Felloe segments 16 16 Spokes left ? 2 Hub boxes 9 Hub liners Forced into hub boxes 2 Outer flanges of hubs 16 16 Carriage-bolt nuts 9 Hub bands Screwed on hub boxes ? Lock washers Between hub bands and hub rings 9 Hub caps . . On end of hubs 2 Hub latches with rivets Actuate hub-latch plungers 9 Hub-latch springs . . 2 Hub-latch plungers Lock hub caps in place ? Oil valves * Slide in hub caps 2 Washers (oil valve) 2 2 Wheel fastenings At ends of axle 9 Consisting of Wheel-fastening plungers 2 Wheel-fastening springs 9 Plugs 1 x I I I *3M* K JBraJse.S'Jtoe PLATC X Panoramic Siykt "" ghielaL J3r-ace- - -vPx-tesSeat JSraJc soever Apron Latcn\ Hood. --Braise JZever* JTla&h ran/c Tt~averstny /fandiuheel Apron Latch, Bracket^ - - -^Sponge feu ten ing JBlocJs. Carrier---'' / , Operating .Lever--'' '' JTame 7>late JSarulsnifse Fastening -Trail Jfandles Lunette Lun et te bracket - - /Scale ^// JO 5 /O fS 20 PS- -70. 35 -fO -(S SO 67 DESCRIPTION OF THE CARRIAGE. [Plates IX and X.] The carriage for the 3-inch gun is of the type known as the long- recoil, in which the gun is permitted a sufficient length of recoil upon the carriage to render the latter stationary under firing stresses. The gun is mounted upon a cradle which forms a housing for the recoil- controlling parts. The cradle rests, and has a small traversing mo- tion, upon the rocker. The latter is journaled upon the axle and its rear end is supported by the elevating mechanism, which is seated in the trail. The principal parts of the carriage are the cradle (complete), trail, elevating gear, traversing mechanism, elevating and traversing lock, shields, axle seats, ammunition carriers, road brake, and wheels. CRADLE COMPLETE. The cradle receives the gun, guides it in recoil, and forms a housing for the recoil-controlling parts ; it consists of a flange steel body bent to a horseshoe shape, with the upper edges flanged outward and connected by a top plate riveted on. The flanges are bronze lined, engage the clips on the gun, and form guides for it in recoil. Riveted to the bottom of the cradle are four steel forgings, the pintle, trav- ersing lug, rear clip, and elevating and traversing lock lug. The pintle fits the pintle socket in the rocker and forms a bearing upon which the cradle is traversed. In normal position, clips on either side of the pintle socket engage projections on the cradle pintle, while the cradle rear clip embraces the rear end of the rocker, locking the two parts together. The cradle is disengaged for dismounting by turning it through an angle of 38. The traversing lug affords a point of attachment for the traversing-link pivot. The cradle rear' clip, in addition to embracing the rear end of the rocker, has a broad bearing on the latter directly over the point of attachment of the elevating screw. To the rear end of the cradle is riveted a steel cradle head,, rear, through which the cylinder moves in recoil and projects for attach- ment to the recoil lug on th.e gun. The clearance around the cylinder in this opening is closed by a felt washer. The front end of the cradle is closed by the cradle head, front, and retaining ring. The latter bears against the front end of the cradle body and is held in position by two swing bolts, one on each side, pivoted to the cradle. The cradle head has on its outside surface an interrupted collar; the bore of the retaining ring is finished with a ring correspondingly inter- rupted. A bushing in the cradle head, front, allows the piston to return to its normal position after tightening the piston-rod nut. The cradle head is assembled in the retaining ring with these inter- 102614^-17 6 68 rupted parts interlocking and is held in that position by a hasp. The cradle-head bushing is bored to take the end of the piston rod, which passes through and is secured to it by the piston-rod nut. The retaining ring is so called because it retains the counter-recoil springs in position in the cradle when the cylinder is removed. The cradle head and retaining ring are arranged as described above, so that the head alone or head and ring together may be quickly dismounted to permit access to the parts within the cradle. The cradle is strengthened on the inside by two bronze pieces called " spring-support guides," placed in the angles of the cradle and riveted to its sides and to the top plate. These pieces are finished with grooves, which receive the guide lugs of the spring support mentioned hereafter, and guide the cylinder in recoil and counter recoil. To the exterior of the cradle are riveted, on the left side, sight-bracket supports for the front and rear sights and fasten- ings for the shoulder guard; on the right side, a range-quadrant fastening, a firing-shaft bearing in carriages Nos. 1 to 168, and a recoil-indicator guide. All carriages after No. 168 have the firing- shaft bracket seat. On soine of the repaired carriages the firing handle bracket seat is an integral part of the cradle head, rear. All of these parts, with others which are riveted to the cradle, are con- sidered integral parts thereof and are included in the designation of " one cradle complete." The recoil-controlling parts of the carriage (PL XI) include the cylinder, piston, counter-recoil buffer, and counter-recoil springs. The cylinder lies inside of the cradle and is surrounded by the counter- recoil springs. It is a steel tube 72.25 inches long and 2.95 inches outside diameter. Its rear end is closed by a steel cyl- inder end which is screwed and pinned in place, and is not to be removed in service. The cylinder end is bored through and tapped to take the cylinder-end stud, which projects to the rear through the recoil lug on the gun, to which it is secured by a nut. The rear end of the cylinder-end stud is bored and tapped to permit the attachment of the spring compressor. When assembled to the cyl- inder, the cylinder-end stud is prevented from unscrewing by a small screw tapped into the cylinder end. When the cylinder is assembled to the recoil lug on the gun, a small pin projects from the front face of the lug into one of five shallow holes bored for the purpose in the rear face of the cylinder and prevents the latter from turning. The front end of the cylinder-end stud is reduced in size and pro- jects 1.875 inches into the cylinder. To this projection is screwed and pinned the counter- recoil buffer, a tapered bronze rod, which fits with small clearance into the piston-rod bore. 69 The front end of the cylinder is closed by a cylinder head screwed into the cylinder to make an oil- tight joint. It should be lashed to the cylinder with copper wire to prevent unscrewing. It is packed with five rings of hydraulic waterproof packing, held by a bronze gland. On the exterior of the front end of the cylinder is a flange which forms a shoulder against which the spring support bears. The cylinder should be held by a wrench on the notches of this flange in assembling or removing the cylinder head. It should never be clamped in a vise. A small hole through the cylinder head is provided for the purpose of draining the cylinder for cleaning. It is closed by means of the drain plug. The interior of the cylinder is cylindrical. Three longitudinal ribs or throttling bars of uniform width but varying height extend from the rear end to within 19 inches from the front end. Notches cut in the piston head form ports for the passage of the liquid from one side of the piston to the other. The height of the throttling bars along the cylinder is calculated so as to make the resistance which the liquid offers, plus the resistance of the springs, constant and such that the recoil will be checked at the desired point. The piston rod is of steel, and is provided with a bronze head, screwed against a -shoulder at the rear end. The head has three notches cut in its perimeter, which fit over the throttling-bar pro- jections on the cylinder walls. The rear end of the piston is bored out to take the counter-recoil buffer. In counter recoil the oil in this bore can escape only by a small clearance. In this way the return of the gun into battery is so eased and regulated that very little shock and consequent derangement of the aim of the piece occurs. The forward end of the rod is also hollow. Near the rear end of this bore three radial holes connect with the interior of the cylinder. The front end of this bore is closed by a filling plug. The piston rod is secured at its front end to the cradle head. A shoulder on the former bears against the cradle-head bushing, while the piston- rod nut is screwed on the rod against the outer face of the head, thus holding the rod against movement in either direction. The counter-recoil springs are assembled in the cradle around the cylinder. Each spring is made from a rectangular steel bar coiled on edge. The spring column of each carriage consists of three of these coils placed end to end around the cylinder and bearing in front against the spring support, in rear against the rear end of the cradle. Issued in place of flat counter-recoil springs: Three outer counter-recoil springs. Three inner counter-recoil springs. Two bronze separators. Each spring is made from a square steel bar. 70 The separators should be assembled between the coils of the springs as indicated on plate. They should be used whenever any of the new outer and inner springs are used, but not between two sections of the old flat springs. In case one flat section spring is to be replaced, the springs should be assembled in the following order beginning at the rear end of the cradle : One outer and one inner spring, one sepa- rator, followed by two flat sections. In case two flat section springs are to be replaced, the springs should be assembled in the following order beginning at the rear end of the cradle: One outer and one inner spring, one separator ; one outer and one inner spring, one sepa- rator, and one flat section spring. The spring support is a steel ring, which fits over the cylinder and bears against the shoulder at its front end. It has guide lugs which run in grooves in the spring-support guides of the cradle. By this arrangement, in addition to taking the spring pressure, the support affords a centering bearing for the front end of the cylinder and pre- alignment of the piston rod and cylinder as the latter recoils with the gun. When the cylinder is removed, the spring support is held in place by the cradle retaining ring. The spring column is assembled under an initial compression of 750 pounds, sufficient to return the gun to battery at 15 elevation. ACTION OF MECHANISM DURING RECOIL. The action of the carriage when the gun is fired is as follows: The gun moves to the rear 45 inches on the cradle, carrying with it the cylinder and compressing the counter-recoil springs. The piston rod is attached to a nonrecoiling part of the carriage, so that as the cylinder moves to the rear the oil in it must pass from one side of the piston to the other. The energy of recoil of the gun is absorbed by the resistance which the oil offers to being forced through small openings past the piston and by the resistance of the counter-recoil springs. The energy stored up by the springs returns the gun to its firing position. This return movement is eased and regulated by the counter-recoil buffer. The piston-rod pull and spring resistance are transmitted to the carriage, but owing to its weight and the resistance opposed to the trail spade by the earth the carriage remains stationary. The length of recoil of the gun upon the carriage is registered by the recoil indicator, a simple friction slide working in the recoil- indicator guide, which is riveted to the right side of the cradle in a convenient, position for observation. The slide is actuated by the recoil-indicator throw, attached to one of the recoil-indicator throw hinges on the dust guard, which moves in recoil with the gun. For carriages after No. 168 the forward hinge is used. For carriages No. 1 to No. 168, inclusive, the rear hinge is used. The length of 71 recoil is read from a scale on the guide, the least reading being 0.25 inch. The gun may be fired by a lanyard attached directly to the trigger of the breech mechanism, but should habitually be fired by. the firing handle on the cradle. The arrangement on carriages Nos. 1 to 168 for this purpose is as follows : A firing-shaft bearing bracket is riveted to the right side of the cradle near its rear end. The fir- ing handle is mounted upon a bronze firing shaft seated in this bearing. The rear end of the firing shaft is squared and projects into the squared hole of the trigger-arm sleeve seated in the recoil lug of the gun. Pulling the firing handle turns the shaft and sleeve and fires the gun, as described heretofore in connection with the breech mechanism. When released the spring and plunger in the handle returns it to firing position. For carriages after No. 168 the arrangement is as follows : A firing- handle bracket seat is riveted to the right side of the cradle near its rear end. On some of the carriages the firing-handle bracket seat is an integral part of the cradle head, rear. The firing handle is mounted upon a steel firing shaft seated in a firing-handle bracket, the whole being held by two studs on the bracket seat. The rear end of the firing shaft is squared and projects into the squared hole of the pallet shank seated in the recoil lug of the gun. Pulling the firing handle turns the shaft and shaft trip collar till the head of plunger hits the adjusting screw, which forces the plunger and the latch upward and releases the trip latch from the trip collar. The shaft-return spring returns the shaft to firing position; the handle- return spring returns the handle to its normal position. The firing handle is of the folding type and has a projection which seats in a slot in the handle bracket. Care should be taken in assembling the handle and shaft-return springs, which are wound right and left hand. The shaft-return spring is left hand and is assembled in the rear of the bracket with the short end of the spring in the lower slot of the bracket. The handle-return spring is right hand and is assembled in the front of the bracket with its short end in the top slot of the bracket. TRAIL. The trail consists of two steel flasks of channel section with the flanges turned inward, tied together by transoms and plates, as de- scribed below. To the front end of each flask is riveted a forged- steel axle bearing, split so as to be slipped over and secured to the axle by clamping bolts. Near the forward end, riveted to the flasks, are the front and rear elevating-gear transoms. Between these two transoms, bolted to and supported by them, are two elevating-gear transoms (middle) which form a seat for the elevating gear. 72 In rear of the elevating-gear transoms are the front and rear tool- box transoms. Between these the trail is provided with a bottom, to form a tool box, which is closed by a hinged lid secured by a spring- handle catch. The portion of the trail between the rear end of the tool box and the wheel-guard transom is formed into a box for the transportation of the rear-sight shank. This rear-sight box is fitted with suitable packing to hold the sight shank in place, and has a lid arranged to be secured in closed position by the tool-box lid and fastening. A padlock, attached by a chain to the left flask, serves to lock both boxes. The portion of the trail in rear of the sight-box lid is closed by a top plate, riveted on. The flasks at the points of contact of the limber wheels when making short turns are protected by small plates called wheel guards, and are strengthened by the wheel-guard tran- som. The rear ends of the flasks are flanged outward to give a firm bearing and support to the spade in which the trail terminates. The spade consists of a piece of flange steel placed crosswise of the flasks and riveted to their flanged ends. Its ends are supported and stiffened by being turned back at right angles to its bearing surface and riveted to the float plate. The latter is also riveted to the upper flanges of the flasks. The wings of the float project on either side of the spade to give sufficient bearing to prevent the end of the trail from burying itself in the ground. A hardened-steel spade edge is riveted to the lower edge of the spade. A lunette bracket and a handspike fulcrum are riveted on the float. The lunette is a steel ring with a stout shank, which passes through a lug in the bracket and is secured in place by a nut, being thus at- tached so as to be easily replaced when worn. The handspike is of the folding type. When not in use it is turned over on the trail and held by a spring fastening riveted to the top plate. Two trail handles are riveted to the upper side of the float. Two seats for cannoneers serving the piece are rigidly attached to the trail, one upon each side, in a convenient position. Attachments for carrying the sponge and rammer are provided on the right flask. On the later carriages the sponge and rammer fasten- ings are placed so that the sponge end is toward the rear. A name plate giving the number, name of carriage, model, name of manufacturer, year of completion, and initials of inspector, is riveted to the tool-box top plate. In all reports and correspondence the carriage should be designated l>y the number and model given on the name plate. ELEVATING GEAB. The elevating gear (PL XII) is of the double-screw type, and con- sists of an inner and outer elevating screw, an elevating-gear bracket. 73 an elevating bevel gear, two elevating bevel pinions, and two ele- vating crank shafts. The inner elevating screw is a steel screw, threaded with a right-hand thread. It is attached at its upper end by the elevating pin to the rear end of the rocker. The outer ele- vating screw is of bronze and is threaded on the exterior with a left- hand thread, while the bore is threaded with a right-hand thread to take the inner elevating screw. On the exterior are also cut two longitudinal keyways, in which the keys of the bevel gear work. The elevating-gear bracket is bored out and threaded to take the outer elevating screw, and is provided with two trunnions which rest in bearings in the elevating-gear middle transoms of the trail. These trunnions are bored and bushed to form bearings for the elevating crank shafts, of which there are two, one on each side of the trail. A steel pinion is pinned and keyed on the inner end of each crank 'shaft and meshes with a bronze bevel gear mounted on the outer elevating screw in a seat slotted through the gear bracket. The bore of the bevel gear is finished with two steel keys which fit into the keyways in the outer screw. This arrangement causes the outer screw to rotate with the bevel gear and at the same time permits it to move longitudinally through the bevel gear. As will be seen from Plate XII, the revolution of the crank han- dles rotates the pinions and through them the bevel gear. The outer screw turns with the latter and moves up or down in the elevating L gear bracket according to the direction of rotation. The inner screw is prevented from rotating by its attachment to the rocker, and on account of the direction of its threads moves into or out of the outer screw as the latter is screwed into or out of the gear bracket. An elevating-screw cover is attached by spring clips to the lower end of the bracket to exclude dust from below. In travel- ing the elevating gear should be run to the position of maximum elevation to house the screws in the elevating-gear bracket. In this position, when properly assembled, the top of the outer screw and the end of the threaded portion of the inner screw are flush with the face of the gear bracket. The mechanism is designed to give a maxi- mum elevation of 15 and a maximum depression of 5. The rocker is the intermediate part between the upper carriage, or cradle, and the lower carriage, or trail. It forms a platform upon which the cradle is moved in azimuth, and moves with the cradle rel- atively to other parts of the carriage in elevation. It is built up of an angle, formed into shape, to which three steel forgings the pintle socket, traversing-gear case, and traversing plate are riveted. Its front end is supported by the portion of the axle between the flasks ; it is assembled by inserting the axle through two bronze-bushed holes in the pintle socket when the trail is assembled on the axle. The upper portion of the pintle socket is formed into a bronze-lined 74 socket and bearing surface for the cradle pintle, and is provided with two clips to take corresponding parts of the latter. The rear end of the rocker terminates in the traversing plate, bronze lined to form a bearing for the cradle rear clip. The lower side of the trav- ersing plate is finished to take the head of the elevating screw, to which it is secured by the elevating pin. The traversing-gear case, which forms a housing for the traversing mechanism, is riveted to the rocker angle in front of the traversing plate. TRAVERSING MECHANISM. The traversing mechanism (PI. XIII) consists of a shaft, called the traversing shaft, mounted in bearings in the traversing-gear case, and a traversing nut moving longitudinally on the shaft, but re- strained from turning with it by its bearings in the gear case. A cylindrical lug on top of the nut fits in a hole in a bronze traversing link, the right end- of which is pivoted by the traversing-link pivot to the traversing lug on the under side of the cradle. This pivot is secured to the cradle-traversing lug by a nut and split pin. The left bearing of the traversing shaft is split for the purpose of assembling and rests between two collars on the shaft. The bearing with the shaft in place is slipped into its seat in the gear case, where it is held in position by two pins. For new work and repairs. The traversing-shaft bearing is made in one piece. One of the collars on the shaft has been removed, in order that the bearing may be slipped in position on the shaft. The shaft is threaded to take a traversing-shaft adjusting nut. Two (special) taper pins hold the bearing in position. The traversing shaft extends to the left of the rocker and termi- nates in a traversing handwheel. When the handwheel is turned the screw threads of the shaft compel the nut to move along it, since the nut is prevented from rotating by its bearings in the gear case, and longitudinal motion of the shaft is prevented by its left bearing. The motion of the nut is communicated through the link to the cradle; the amount of motion thus provided for is 140 mils, 70 on each side of the axis of the carriage. An azimuth scale riveted to the rocker and a pointer attached to the cradle show the position of the gun in azimuth; the scale is graduated to a least reading of 5 mils. ELEVATING AND TRAVERSING LOCK. To relieve the pointing mechanism from all strains in traveling, an elevating and traversing lock is provided, by which the cradle may be securely locked to the trail. This lock consists of a stout hook hinged to the rear elevating-gear transom in such a position as to engage the elevating and traversing lock lug riveted to the under ^ ^ 75 side of the cradle at its rear end. The hook is arranged to be held in either the locked or unlocked position by a steel spring. THE SHIELDS. The shield for the protection of the crew is an armor plate, 0.15 inch thick, made in three parts the apron, the main shield, and the top shield. These shield plates were originally made 0.2 inch thick, and in order that the new shields may be interchangeable with the older ones, four bracket-fastening filler pieces and four apron-hinge filler pieces, each 0.05 inch thick, are provided with the new shield for all carriages to which they may be fitted. The apron is hinged under the axle and reaches to within 5 inches of the ground. For traveling it is swung up under the ammunition- carrier tubes and is held by two apron latches, which are attached to brackets riveted to the tubes. The main shield is rigidly attached by bolts to the bracket fastenings and to lugs on the trail-axle bearings, and is braced by two shield braces reaching from its upper corners to the ammunition-carrier tubes. It has two wing nuts for securing the top shield when folded down, and has a sighting port and a gun port. The latter is made a minimum port and the shield is stiffened by a hood riveted to its front face. The main shield reaches from the axle to 4 inches below the tops of the wheels. . The top shield is hinged to the main shield, has a panoramic sight port and is provided with two fastenings which secure it in either the raised or folded position. The upper edge of the top shield is 62 inches from the ground, sufficient to afford protection from long- range or high-angle fire to cannoneers on the trail seats. The panoramic and open sight ports are provided with shutters, hinged to the main shield. The open sight port shutter has a sup- port which bears upon the main shield and holds the shutter in an open position. The shutter of the panoramic sight port, when open, rests upon the open sight port shutter. When closed the panoramic sight port shutter is held in position by a latch. For the protection of the cannoneer sighting the gun a shoulder guard is attached to the left side of the cradle at the rear end. The fastenings for the guard are riveted to the cradle, but the guard itself is detachable and is secured in place by a steel pin. A sheet-steel box, with leather-lined packing blocks called the "panoramic-sight case," attached to the rear face (left side) of the main shield, provides a place for the panoramic sight in traveling. This box has a hinged lid, secured by a hasp and wing nut, and is provided with the usual padlock with chain for locking the box. The sight-case bracket is fastened to the shield by five bolts. The sight case is supported between springs compressed between sup- ports on the bracket and held in place by bolts acting as spring rods. 76 The mounting is thus such that the sight is well protected from in- jury due to shocks and jars. A similar case, called the range quadrant case, is attached to the right side of the main shield by means similar to those just described and is provided for the safe transportation of the range quadrant. A sheet-steel dust guard, assembled on the cradle between the locking hoop and clip of the gun, covers and protects the guide rails from dust and dirt. The dust guard is fitted at its forward end with a bristle brush and felt wiper, which sweep the upper surface of the cradle at each stroke of recoil and counter recoil. All working and bearing surfaces of the carriage require oiling; those not directly accessible for this purpose are provided with oil holes closed by spring covers or handy oilers. AXLE SEATS. Each axle seat and each pair of ammunition- carrier tubes is sup- ported by two steel bracket fastenings, which are secured upon the axle by bolts and are prevented from turning by the axle keys. A steel plate, called a "tube-support plate," perforated with two flanged holes, is bolted to these bracket fastenings. Two plate angles are riveted to the tube-support plate in order to make it more rigid. Two 4-inch steel tubes are riveted to the flanges of these holes and project to the front, where their ends are riveted to a brake-beam tube and fashioned to form a foot rest for the cannoneers. This brake-beam tube is fitted to form fulcrum and guide bearings for the road brake beams. The forward ends of the ammunition carriers are braced by tie-rods from the lower side of the axle bracket fastenings and by a shield brace to the shield and the upper ends of the seat arm and seat-arm support. An apron-latch bracket is located between each pair of ammunition tubes and firmly riveted to them. The apron-latch body is pivoted on a block bolted to this bracket; the lower end of the latch body is formed into a hook which engages a latch staple riveted to the apron shield and holds the latter in its traveling position. To prevent acci- dental disengagement of the hook from the staple, the opening of the hook is closed by a plunger seated in the latch body and pressed outward into action by a coiled spring. An apron-latch lever is provided for withdrawing the plunger from the hook opening when it is desired to disengage the hook from the staple. The axle seats, formed of flange steel, are bolted at the rear to the tube-support plate ; at the front it is supported by the seat support, the two ends of which are bent back and bolted to the axle bracket fastening. Each seat is provided with a wheel guard, formed of two small steel tubes, called the "seat arm" and "seat-arm support," 77 and of a sheet-steel piece, called the " seat-arm guard," secured to the seat arm and the shield brace. The top shield, folded down for traveling, serves as a back rest for the cannoneers on the axle seats. AMMUNITION CABKIEES. The ammunition carrier tubes project to the rear over the axle and under the seat, and are fitted inside with bearings to take each a round of ammunition. Their rear ends are closed by a hinged cover secured by a spring latch. ROAD BBAKE. The brake beams are pivoted on fulcrum pins in bearings in the brake-beam tubes at the front ends of the ammunition carriers. Cast-iron brake shoes are attached by tap bolts to the outer ends of the beams. To their inner ends are pinned brake rod ends, into which the brake rods are screwed. The brake-rod spring slips over the rear end of the brake rod and abuts against a shoulder upon it. The spring is covered by a tube called the " spring cover," in- closed at each end by bronze pieces, called the " spring-cover head " and " spring-cover end." The spring is compressed between the spring-cover end and the shoulder on the- brake rod, while the rod is arranged to have a short longitudinal movement against the pres- sure of the spring. The spring-cover ends are pinned to cranks on squared ends of the brake shaft, which is mounted in lugs project- ing to the front from the trail axle bearings. The brake lever (which serves as the crank at the right end of the shaft) is double, one arm projecting to the rear through a slot in the main shield, while the other is conveniently placed for use from the right axle seat. When the brakes are set, the lever is held by engaging in the teeth of the rack on the brake segment. The latter is a flange steel piece, with a flange in which are riveted two hardened tool-steel racks, riveted to a brake segment bracket, which is clamped and keyed to the axle. The levers are made of spring steel. Adjustment to compensate for wear of the brake shoes is provided for by the distance which the brake rods are screwed into the brake rod ends. The tension of the brake rod spring is regulated by screwing the spring-cover end into or out of the spring cover, thus shortening or lengthening the spring space in the cover. The brake is to be used as a firing as well as a road brake. THE WHEELS. The wheels are a modified form of the Archibald pattern, 56 inches in diameter, with 3-inch tires. The hub consists of a forged steel hub box and hub ring assembled with eight carriage bolts through the flanges and with a bronze hub cap screwed on the outer end of the hub box. The hub band is screwed on the hub box. A lock washer is placed between the hub ring and the hub band, preventing the latter from unscrewing. The hub band should be screwed up as 10261417 7 78 tightly as possible with the wrench and finally forced by striking the end of the wrench with a wooden block or mallet. The bronze hub cap is screwed on the hub box and is locked with the hub-latch plunger, which is withdrawn and held in the disengaged position by the hub latch when the hub cap is to be unscrewed. Assembled to the hub cap and projecting into the axle arm is an oil valve, through which the wheel is oiled without removal. The hub box is fitted with a bronze liner, forced into place. The liners are removable. The tire is shrunk on and secured to the felloe by eight tire bolts. The wheel fastening consists of a bronze yoke fitting in the outer end of the axle arm and is accessible when the hub cap is removed. The axle is hollow and forged from a single piece of steel ; the keys, solid with the axle, hold the axle bearing, bracket fastenings, and segment bracket in their places. The axle arms make an angle of 1 11.5' with the axle. This brings the lowest spoke of each wheel vertical. DISMOUNTING AND ASSEMBLING GUN AND CARRIAGE. To remove the recoil indicator. The ends of the clips of the recoil- indicator guide are bent down to form stops to hold the indicator in place. To remove the indicator, these parts are opened up suffi- ciently to permit sliding the indicator out of the guide. When the indicator is assembled, these clips should always be closed down to prevent its loss. To dismount the gun. Remove the recoil-indicator throw, unscrew the cylinder-end stud nut, and shove the gun to the rear until the clips are free from the guides. To mount the gun. Shove the piece from the rear over the cradle guides with the clips engaging the guides. Assemble the cylinder- end stud nut, taking care that the locking stud on the recoil lug enters one of the recesses provided for it in the end of the cylinder. Assemble the recoil-indicator throw. The dust guard should be assembled with the gun. In moving the gun on or off of the cradle particular care must be taken to support the breech end so that the gun clips remain in line with the gun slides. The firing shaft is also quite liable to injury during this maneuver, and care should be taken to prevent its being struck by the muzzle of the gun or by implements in the hands of the cannoneers. The cradle should be placed at the desired elevation and azimuth before beginning either of these maneuvers and not changed during its progress, since the working of either the elevating or traversing mechanisms when the gun is only part way in battery brings an excessive and unnecessary strain and wear upon those parts. To dismount the cylinder. Bring the gun to approximately zero degrees elevation ; unscrew the cylinder-end stud nut and the piston- 79 rod nut ; remove the cradle head front. The cylinder is now free and may be pulled out to the front. To assemble the cylinder. The springs and retaining ring being in assembled position, shove the cylinder (turned so that the drain plug in cylinder head comes on top) into its seat from the front, \v i th the projecting stud on the recoil lug of the gun entering one of the recesses provided for it in the cylinder end; assemble the cradle head: screw in place the piston-rod nut and cylinder-end stud nut. Be sure that the projecting stud on the gun enters one of the holes for it in the cylinder end before screwing the cylinder-end stud nut up all the way. To dismount the springs. Bring the gun to approximately zero degrees elevation ; unscrew the cylinder-end stud nut and the piston- rod nut ; shove the gun about 1 inch from battery ; attach the sleeve end of the spring compressor ~to the cylinder-end stud and put sufficient strain on the compressor to relieve the retaining ring from spring pressure; then remove retaining ring (and cradle head) by loosening and swinging aside the retaining- ring bolts; ease off on the spring compressor until the springs are free. To assemble the double counter -recoil springs. With the cradle at maximum elevation and the trail horizontal, place one outer and one inner spring in the cradle until the front ends are about 2 inches in ; set up a separator against the forward end of these sections and enter the second outer and inner springs, keeping the separator upheld between the sections; similarly when the outer end of the second section is 2 inches inside the cradle set up the second sepa- rator ; place the third outer and inner sections on the recoil cylinder. Screw the spring centering tool onto the cylinder-end stud, the small end pointing rearward ; pass the sleeve end of the spring compressor through the gun lug and the inner springs and attach it to the cylin- der-end stud. Enter the rear end of the cylinder in the spring at the front end of the cradle and push the cylinder back until the springs are at free height, keeping the spring compressor taut. Attach the block and fall carried in the battery .wagon to the spade of the car- riage or to some improvised support and connect it to the spring compressor; put sufficient strain on the spring compressor to bring the spring column to its assembled height. As the spring column approaches its assembled height the spring support must be turned so that its guide lugs properly enter in the spring-support guide grooves in the cradle; assemble the retaining ring, disconnect the spring compressor and the spring centering tool from the cylinder-end stud; push the gun back into battery and assemble the cylinder-end stud nut. When the retaining ring is assembled the nuts for the retaining ring bolts should be screwed up until they just come into contact with the retaining ring. If these nuts are screwed up too tight they will deform the retaining ring, 80 with the result that it becomes difficult to assemble and dismount the cradle head. A wrench is provided for turning the spring sup- port to its proper position. To assemble the single counter -recoil spring. The same method is followed except that no separators are used. The spring compressor is provided with a second -eye at its large end which may be used in case the sleeve end should become broken; in case this end is used, however, it will be necessary to pass the compressor through the cradle from front to rear, through the gun lug. For disconnecting the compressor the method used is identical to that previously described. The cylinder-end stud nut should never be removed when the gun is at an elevation, and the gun should not be elevated when the cylinder- end stud nut is not in place. To prevent the cylinder-end stud from rotating a screw for the cylinder end is provided. This screw for the cylinder end must be removed before attempting to unscrew the cyl- inder-end stud. The springs are assembled under an initial load of over 750 pounds ; a pull of more than 750 pounds must therefore be exerted upon the spring compressor in assembling them. This can be done by passing a, handspike through the loop at the rear end of the compresser and making use of the services of the entire gun crew, or the block and tackle may be used as described above. To avoid the possibility of injury to the gun crew in compressing or releasing the springs, all should be required to keep arms and bodies away from the front of the spring column during these operations. To fill the recoil cylinder. // the cylinder is not completely filled, loss of stability will occur and higher stresses than normal will be de- veloped in the carriage; -for this reason the cylinder should be -filled with the greatest care; a commissioned officer should himself verify that the cylinder is full and that no air is left in it, with the excep- tion of the void noted below. The easiest way to fill the cylinder is when it is disassembled from the carriage. If assembled to the car- riage bring the gun to its maximum elevation and remove both -filling and drain plugs. It is necessary that the drain-plug hole should be located on top of the cylinder. Fill through the hole in the piston rod. Allow a few minutes for the air to escape and the oil to settle. Refill and repeat two or three times. When satisfied that the cylin- der is entirely full of oil, insert both plugs, and depress the gun to its 'maximum depression. After a few minutes elevate again to maxi- mum elevation and unscrew both plugs. Now refill as described above. When entirely full allow not more than 2 cubic inches (about one-fourth of a gill] of the oil to escape; insert both plugs and lash them with copper wire. It may happen that after firing a few rounds the gun will not re- turn to battery. This may be due to, first, weakness of springs; 81 second, stuffing-box gland being screwed up too tightly; or, third, the oil having expanded, due to heat. In either case the cause must be ascertained and remedied ; if due to expansion of oil it is proven by the fact that the gun can not be pushed into battery by force exerted on the breech of the gun. In that case elevate the gun to its maximum elevation and remove the filling plug. The oil will now escape, permitting the gun to return to battery. About 9 pints of oil are required for filling the recoil cylinder. Hydroline oil of a specific gravity of 0.85 is furnished by the Ord- nance Department for use in these cylinders; it is characterized by its low freezing point and by its noncorrosive action on metals. The oil used in the cylinder should be clean and free from grit and dirt; to insure this it should be strained through a clean piece of linen or muslin before using. In emergencies water may be used in the cyl- inder. This should be done only when absolutely necessary, and never in freezing weather, and as soon as practicable the cylinder should be emptied, cleaned, and thoroughly dried and -filled with hydroline oil. To pack the stuffing box. The stuffing box is packed with five rings of Garlock's hydraulic waterproof packing, 0.25 inch square. The packing is issued cut into rings of such size that the ends meet around the piston rod. The latter being assembled, each ring, placed so as to break joints with preceding one, is forced in succes- sion into its seat by a packing tool of copper or hard wood, one end of which is shaped like a carpenter's gouge and the other end forms a handle strong enough to stand light taps from a hammer. Such a tool may be readily improvised by the battery artificer. After the five rings are firmly seated in the box, screw the gland down on the packing. In assembling the gland be sure that at least four of its threads are engaged with the threads of the cylinder head ; otherwise the threads of the gland may be stripped in firing. With new packing it may be found difficult to insert more than four rings and secure sufficient engagement of the gland. In such a case the box should be packed with four rings and the piece fired a few rounds, after which the fifth ring should be inserted. Adjustment of the gland. The adjustment of the gland will require the exercise of some judgment. If screwed up too tight, the fractional resistance of the packing on the piston rod will be so much increased that the counter-recoil springs may fail to return the gun to battery, especially at high angles of elevation. It should be screwed up just tight enough to prevent the leakage of oil through the stuffing box. Ordinarily this can be done by hand, but in cases where hand power is not sufficient the wrench provided for the pur- 82 pose should be used. When its proper adjustment is determined, the gland should be lashed with copper wire to prevent it from screwing up or unscrewing. To remove the piston rod. Unscrew the gland sufficiently to release the pressure of the packing upon the rod ; unscrew and remove the cylinder head. The rod may then be withdrawn from the cylin- der. In dismounting and assembling the cylinder head (and also the cylinder-end stud), the cylinder should be held from turning by a spanner applied to the head retainer or flange on the front end of the cylinder. It should never be clamped in a vise, as its walls are thin and not intended to withstand such usage. To remove the counter-recoil buffer. Remove the cylinder-end stud screw ; unscrew and remove the cylinder-end stud ; the counter- recoil buffer is attached to the latter. The necessity for dismounting parts of the cylinder will seldom arise. It should be done only in the presence of a commissioned officer, who should see that the parts are handled with the greatest care. In assembling, the parts should be thoroughly cleaned, as the clearances in the cylinder are very small, and the presence of small foreign particles may interfere with the proper working of the assembled parts. The cylinder head should be set up hard with a wrench and then lashed with copper wire to prevent unscrewing. To dismount the traversing mechanism. Traverse the cradle (muz- zle end) to its extreme left position; remove the nut which secures the traversing-link pivot to the cradle lug; remove the traversing- link pivot from below; turn the link so as to clear the heads of the traversing shaft-bearing pins and remove these pins; unscrew the worm shaft from the nut and at the same time withdraw the shaft with its left bearing from the gear case. Now move the cradle in azimuth to its extreme right position; slip the link off of the nut and remove the nut from the gear case. To dismount the left bearing of the shafts equipped with the adjusting nut and one piece bearing, all that is necessary is to remove the adjusting nut and slip the bearing off the shaft. To assemble the traversing mech- anism, the above operations are reversed. In certain carriages of earlier manufacture (Nos. 1 to 10 and 19 to 26, inclusive, Rock Island Arsenal) the foot rest at the front end of the ammunition tube prevents the cradle from being traversed far enough to the right to permit the removal of the traversing . link by the method just given. For such carriages the traversing-link pivot, travers- ing shaft, and traversing-shaft bearing may be dismounted as stated, but the right ammunition carrier must be removed from the car- riage before the cradle can be traversed far enough to permit the removal of the link. To dismount the elevating screws. Remove the elevating pin; unscrew the inner screw by hand ; remove the elevating-screw cover ; 83 remove the outer screw by screwing it down through the. elevating- gear bracket. To dismount the pinions and bevel gear. Remove the taper split pin in the pinion hub, after which the crank shaft may be withdrawn and the pinion removed from its seat. The bevel gear may then be removed by dismounting the screws as above. To dismount the elevating -gear bracket. Free the mechanism from the rocker by removing the elevating pin; dismount the pinions and crank shafts as above; remove the eight elevating-gear transom bolts; the bracket and transoms are then free and may be removed from the trail. To assemble the elevating mechanism. The operations just de- scribed are reversed. The following should be noted: The pinions are a close fit on the crank shafts, and especial care should be taken not to burr the parts in assembling. When properly located, the two crank-shaft handles balance each other. This condition obtains when they are simultaneously horizontal and both pointing to the front or both pointing to the rear. As the outer screw is assembled in the gear bracket from below, the bevel gear should be put in place with its key engaging the keyways of the screw. Before attaching the inner screw to the rocker both screws should be run down to be sure that the upper ends of the threaded parts of the screws are flush with the face of the gear bracket. If this condition is not fulfilled the' mechanism will not give the maximum elevation and depression for which designed and will not house properly in traveling. To remove the shields. The main shield is freed from the carriage by removing the bolts which secure it to the bracket fastenings, axle- bearing lugs, and shield braces. The apron is detached by removing the apron-hinge pins. To remove the apron latch. Remove the bolt which secures the apron-latch block to the bracket riveted to the ammunition tubes. The block, with latch, can then be slipped to the front, clear of the bracket. To dismount the cradle. Remove the traversing gear (it will suf- fice to remove the traversing-link pivot and to remove the handwheel from the traversing shaft) ; remove the three shield bolts and shield- brace bolt ; slip end of shield brace from tie-rod fastening ; raise the right axle seat (and for carriages of earlier manufacture, as Nos. 1 to 10 and 19 to 26, R. I. A., the right ammunition carrier) as described below ; swing the rear end of the cradle 38 to the left, and then lift it clear of the carriage. To remove the road brake. The brake rods are dismounted by removing the brake-rod pins which attach the front ends of the rods to the brake beams and the rear ends to the brake crank and the brake lever. 84 The brake-beam fulcrum pins are removed by driving them upward out of their seats; the brake beams are then free and may be removed from the carriage ; the brake shoe is freed from the beam by unscrew- ing the brake-shoe tap bolts. The brake crank may be slipped off the left end of the brake shaft after removal of the split pin. The brake lever is dismounted by moving the brake shaft a short distance to the left through its bear- ings ; by a continuation of the movement to the left the brake shaft is removed from the carriage. The brake segment is dismounted by removing the segment-bracket clamping bolt and slipping the bracket off of the axle (the right ammunition carrier having first been dismounted as described below). To assemble the road brake. The operations just described are reversed. The following should be noted: The brake beams, with shoes attached, are rights and lefts, and are properly assembled when the shoe has a full bearing upon the tire. Keversing the shoe upon the beam changes the combination from a right to a left, or vice versa. The brake crank when correctly assembled on the brake shaft is parallel to the crank end of the brake lever. The tension of the brake rod spring is regulated by removing the split pin, which passes through the spring cover, and screwing the spring-cover end into or out of the spring cover. The tension of the spring is increased by screwing the end into the cover. The length of the brake rod should be adjusted by screwing the front end of the rod into or out of the piece attaching the rod to the brake beam. To adjust the road brake. The brake rods are disconnected from the brake beams. The brake shoes are placed with the clearance from the tire desired and the brake lever with handles in extreme forward (released) position. The length of the brake rods should then be adjusted to correspond. Should test show that one shoe bears harder on one wheel than the other, the brake rod of the latter should be lengthened. To remove a 7mb liner. Remove the wheel from the axle and drive the liner out by striking with a heavy hammer or sledge upon the hub-liner driving tool (a bronze tool carried in the forge limber) placed against the small end of the liner. To remove a wheel. First remove the hub cap. then the wheel fas- tening, and then the wheel. To remove a hub cap. First lift the hub latch which removes the hub-latch plunger from the hub band and then unscrew the hub cap by turning it to the left. To remove a wheel fastening. First lift the wheel-fastening plunger until it is clear of the axle and then lift the wheel fastening off of the axle. To remove the axle seats and ammunition carriers. The wheels, wheel fastenings, and shields having been dismounted, remove one of 85 the brake rod pins to free the brake beam ; then remove the bracket- fastening clamp bolts and slip the bracket fastenings, with axle seats and ammunition tubes attached, off of the axle. To remove the axle seats. It is sometimes desired to remove the axle seat without the ammunition carrier, and thus avoid dismount- ing shields and wheels. This may be done by removing the three bolts which hold the rear edge of the seat proper, the two special bolts which hold seat support in bracket fastening, the bolt at the upper end of the shield brace, and the tie-rod fastening nut at the lower end of the shield brace. The seat, with seat support, seat arm, seat-arm support, seat-arm guard, and shield brace attached, is then free and may be removed from the carriage. To dismount the trail and rocker. The wheel, wheel fastening, shields, axle seat, etc., having been removed as described above, remove the axle-bearing bolts and slip trail and rocker off the axle. The parts of this carriage in general are made with sufficient clear- ance to permit of the assemblage of any part without the use of force. In assembling them no part should be directly struck with a hammer. If resort to force is necessary, a piece of wood or copper should be interposed between the hammer and the part struck. All nuts are provided with split pins as keepers. The split pin must, of course, be removed to remove the nut, and when the nut is assembled the split pin should be inserted and properly opened. Certain parts are lashed with wire to prevent unscrewing. A spool of copper wire is provided in the tool box for this purpose. A pair of wire-cutting pliers is also provided for use in pulling split pins, cutting wire lashings, etc. CARE AND CLEANING OF RECOIL CYLINDERS AND OTHER PARTS OF CARRIAGE. The carriage must be properly cleaned and cared for to insure its working correctly. The officers responsible for the efficiency of the battery should familiarize themselves with the carriage mechanism and with the foregoing instructions as to the methods of mounting and dismounting the various parts, and should see that the carriage is properly handled, cleaned, and cared for. The following general directions for its care and cleaning are given : The recoil cylinder should be emptied and refilled once every three months, and thoroughly cleaned once every six months, or oftener if the conditions require it. The cylinder is most readily emptied and filled when removed from the carriage. For cleaning it is dis- mounted and the cylinder head, counter recoil buffer, and piston rod removed, as heretofore described. The interior of the cylinder, the piston, the counter recoil buffer, and the stuffing box should then be thoroughly cleaned by the use of cotton waste and coal oil and wiped dry with cotton waste. The removal of the packing is not 86 necessary in cleaning. The cylinder bore should be carefully in- spected, and if any rust has formed it should be removed with coal oil, using, if necessary, -fine emery cloth. The latter must be used with great care to prevent any increase in the clearance be- tween the cylinder and piston. If rubbing, burring, or scoring of the parts is noted, the rough spots should be carefully smoothed down by a skilled workman with a dead-smooth file or with emery cloth, and the cause of the roughness ascertained and removed. Where unusual rubbing or scoring has occurred, the facts will be reported to the officer of the Ordnance Department charged with the duty of keeping the battery in repair for his information and action. The parts should be reassembled immediately after cleaning and inspection, and the cylinder filled with the hydroline oil issued for that purpose. The piston should be moved back and forth in the cylinder by hand to make sure that all parts are correctly assembled and are without interference. The cylinder should then be mounted in the carriage and the gun pulled from battery by hand and per- mitted to counter recoil rapidly to insure that all parts are in proper position for firing. This should never be done, however, unless the cylinder is known to be filled with oil. In reassembling the parts the condition of the vulcanized-fiber washers between cylinder head and cylinder and cylinder-end stud and cylinder end should be noted: they should be replaced whenever necessary to prevent leakage. In removing and inserting the piston rod care should be taken to keep it central in the cylinder, so as not to bind, burr, or spring any parts. The dismounting and reassembling of the parts of the cylinder should in every case be supervised by a commissioned officer. Before firing, an inspection should be made to ascertain that the different parts, especially the piston rod and cylinder-end stud nuts, are correctly assembled. The recoil-cylinder oil should be stored in the closed cans pro- vided for the purpose, and be carefully protected from dirt, sand, or water. Oil withdrawn from cylinders and containing any sediment must not be used again until it has been allowed to settle for not less than 24 hours. When sediment has thus been permitted to settle, great care must be taken not to disturb it in removing the oil. To insure the cleanliness of all cylinder oil it should be strained through a clean piece of linen or muslin before using. The exterior of the cylinder should be kept well oiled and free from rust or dirt, and an inspection made at least once each month to ascer- tain its condition. Where rust has formed it should be removed with coal oil and, if necessary, emery cloth. For shipment or storage, or where the carriage is to stand without firing for extended periods, the cylinder should be coated with the light slushing oil used for the bores of guns. 87 The counter-recoil springs should be dismounted at least once every six months and be thoroughly cleaned. All rust should be removed and the springs well oiled before reassembling. When the springs are dismounted the interior of the cradle should be cleaned and exam- ined for defective riveting, missing rivet heads, and scoring. The condition of the spring-support guides should be noted and all burrs or scores carefully smoothed off. The recoil guide rails of the cradle should be kept well lubricated. Immediately before beginning to fire, they should be oiled through all the oil holes of the gun and dust guard. Lack of proper lubrica- tion of these guide rails is the most frequent cause of failure of gun to return fully into battery. The contact surfaces between cradle and rocker should be kept clean, thoroughly oiled, and free from rust. If indications of rust- ing, cutting, or scoring of these surfaces appear, the cradle should be dismounted, the rust removed, and the rough spots smoothed away. The elevating and traversing mechanisms should be dismounted at least once every six months for thorough cleaning and overhauling. They should be kept well oiled and should work easily. If at any time either mechanism works harder than usual, it should be imme- diately overhauled and the cause discovered and removed. In traveling, the cradle should be locked to the trail by means of the elevating and traversing lock, so as to relieve the pointing mechanisms of all travel stresses. The wheels and wheel fastenings should be dismounted period- ically and the fastenings, hub boxes, axle arms, and axle bore cleaned and examined. All roughness due to scoring or cutting should be smoothed off. - The hollow part of the axle acts as a reservoir for the oil to lubri- cate the wheel bearings. Experience will show how much oil is needed, but enough should be used to insure t{iat the oil will pass through the axle arms to the hub caps. The nuts on the hub bolts should be tightened monthly during the first year of service and twice a year thereafter. The ends of the bolts should be lightly riveted over to prevent the nut from un- screwing. When the hub bolts are tightened, the hub band should be screwed up as tightly as possible against the lock washer at the outer end of the hub ring. The importance of strict compliance with these instructions can not be overestimated. The wooden parts of the wheels are made of thoroughly seasoned materials, and the hub bolts and bands, when the wheels are issued, are properly tightened ; but all wood is suscepti- ble to change with atmospheric conditions, so that the spokes speedily become loose, and if the wheel is used in this condition it will rapidly be made unserviceable and may be damaged beyond repair. 88 THE 3-INCH GUN LIMBER, MODEL, OF 1902. [Plate XIV.] WEIGHTS, DIMENSIONS, ETC. Weight, complete, empty . pounds 964 Weight of tools and equipment carried do 101 Weight of ammunition carried - do 675 Weight, completely equipped and loaded do 1, 740 Weight of gun, carriage, and limber, completely equipped and with 40 rounds of ammunition pounds 4, 260 Rounds of ammunition carried in limber chest number 36 Diameter of wheels inches__ 56 Width of track do____ 60 Free height under limber (and carriage) do 22 Turning angle with carriage degrees 80 Turning angle with caisson do 75 NOMENCLATURE OF PARTS. No. Name of part. Location, etc. Property clas- sification. Class. Section. 2 1 1 1 1 1 1 1 1 1 2 1 1 1 1 6 2 2 Wheels and wheel fastenings Same as on carriage 1 VI 3 Axle Middle rail (upper and lower half) Consisting of Pole clamp Pole-prop oracket Riveted to axle Riveted to middle rail Riveted to pole clamp and middle rail with limber prop in place. In pole clamp Pole-clamp bolt Pole-clamp nut Pole pin Secures pole in seat Pole-pin reinforce Riveted to lower half of middle rail Riveted between upper and lower half, of middle rail. Riveted to middle rail with side rails. . Riveted to middle rail Pole stop Separating pieces Doubletree strap Doubletree bolt In bolt clamp and doubletree strap Doubletree nut Side rail (right) Riveted to axle and middle rail Consisting of Reinforce plate, front Riveted to side rail Reinforce plates, rear do Sleeves. . . ...%... .... do Step do Pole-prop Docket do Side rail (left) Riveted to axle and middle rail Consisting of Reinforce plate front Riveted to side rail Reinforce plates, rear do Sleeves do Step .. do Pole-prop support do ... Strap fastener Riveted to side rail, for pole-prop strap. Riveted to middle rail Name plate Limber prop Assembled to middle rail by means of pole-clamp eye. Consisting of Limber-prop foot Limber-prop eye Pinned to top of prop * . Chain Secured to prop foot Prop tube Hinged to pole by prop eye Prop-chain fastening . Riveted to chain Prop-chain eye Riveted to prop tube Tie-rod, rear (right) Brace middle rail from axle . . . Tie-rod, rear (left) do Tie-rods, front do Tie-rod clamp (right) On fl.-rln arms Tie-rod clamp (left) do Tie-rod pins. . . . Fasten finds of tift-rnds Doubletree rods From doubletree to axle Doubletree rod Dins. . . Secure rods to tie-rod damns... 89 NOMENCLATURE OF PARTS Continued. No. Name of part. Location, etc. Property clas- sification. Class. Section. 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 10 1 1 1 1 1 il 1 1 1 1 1 1 1 1 1 1 1 1 2 1 I I 1 2 1 1 1 1 1 2 1 1 1 1 1 1 1 8 4 4 1 1 4 4 4 Foot rest, consisting of Riveted to foot rest IV 3 Angle piece (left) do .. do Pick-handle rest large end do do Pick pocket nee'dle end do Pick head lower strap fastener do...., do do ...do do Pintle with bearing, complete, consisting of Pintle Seated in pintle bearing Pintle latch On pintle Pintle latch pin with split pin Pintle latch spring Forms pivot of latch On pintle Pintle bearing (in two parts) Rear end of middle rail Pintle spring In pintle bearing Pintle spring pin do Pintle bearing bolts with nuts Secures bearings to middle rail Doubletree On doubletree bolt Consisting of D oubletree body with reinforce Riveted together Separators .. Nipple separator Double hook (right) Renewable Double hook (left) Nipple nut Pole, complete, consisting of Pole body Riveted, in body Neck-yoke counter stop spring Bears on neck-yoke counter stop . Neck-yoke counter stop pin Neck-yoke counter stop Riveted in body Hinges on counter stop pin . . . Riveted to body Neck-yoke chafing plate Riveted to upper side of body . . . Inside of body Neck-yoke stop rivet separator .. do Pole pin bushing Butt reinforce do Riveted to inside of body Ammunition chest, complete, consisting of Door chains Attached to chest door Shot bolt (right) On chest door Shot bolt (left) do Shot-bolt bracket (right) Riveted to door Shot-bolt bracket (left) do Shot-bolt stops do Padlock Fastened to chain Padlock chain ... Fastened to door Lock hinge Riveted to door Lock hasp Hinged to door Hinse Bin Lock cam Riveted to top of chest Lock bolt In lock hasp . . On lock bolt Lock handle .do .... Handrail tubes Riveted on handrail brackets so as to make rights and lefts. Riveted on chest Handrail forward bracket (right) Handrail forward bracket (left) do. Handrail rear bracket (right) do Handrail rear bracket (left) do Bucket holder Riveted to top of chest, forms seat. .. . Chest rail (right) Riveted to bottom of chest Chest rail (left) - . . do Washers On chest-rail rivets . . Chest-rait connections Riveted to chest Connection pins Fit through side rails and chest-rail connections. Body lower plate Body, upper plate Door hinges male Riveted to door Door hinges female Riveted to chest bottom Door-hinge pins. . . Fit in door hinges. . . 1 The components are for the steel pole, which will be issued to replace the wooden pole when the latter becomes unserviceable and the present supply of wooden poles is exhausted. 90 NOMENCLATURE OF PARTS Continued. No. 7 Name of part. Location, etc. Ammunition chest, complete, consisting of Continued. Door-chain fasteners Riveted on d9or Diaphragm angles Riveted on diaphragms. Filler piece (right) ; Under shot-bolt bracket Filler piece (left) i do Pa ilock staple ! Riveted to door Chest -front reinforce Rivetei to chest front. . Front diaphragm Riveted to chest body. . , Mi Idle diaphragm | do Rear diaphragm I do Dis Stiffener . Chest front Door Door frame Ammunition-chest connecting pieces . Reinforce pieces Hatchet-blade bracket Hatchet-handle fastener Pick pocket, chisel end Ax-hea 1 bracket Sho v-el-blade bracket Lantern bracket, consisting of Lantern-bracket bo ly Lantern-bracket bottom Lantern-strap fasteners Grip-strap fasteners Strap fasteners for paulin strap. . Rope-strap fasteners Rope-strap fasteners (special) . Strap fastener for ax strap Shovel-handle bracket. . . . Connects front and middle diaphragms Riveted to chest body ....do Hinged to chest bo ly Riveted to door Connects rear and middle diaphragms. Brazed on ammunition-chest connect- ing pieces. Riveted to chest ...do.... ....do ...do ...do.... Property clas- sification. Class. Section. ....do Riveted to body do Rivete I to chest Rivete d to bucket holder Riveted to chest; 8 are for blanket straps. Riveted to chest Riveted to foot rest and middle rail IV DESCRIPTION OF THE 3-INCH GUN LIMBER, MODEL OF 1902. [Plate XIV.] The limber is of metal throughout, excepting the spokes and felloes of the wheels. The principal parts are the wheels, axle, frame, ammunition chest, pole, doubletree, singletrees, and neck yoke. The wheels and wheel fastenings are the same as, and interchange- able with, those used on the carriage. The axle is hollow and is made of a single piece of forged steel. The axle arms and the grooves for the wheel fastenings are finished to the same shape and size as those of the carriage axle. The axle body is provided with lugs, to which the middle and side rails of the frame are riveted. The frame consists of a middle and two side rails riveted to the axle lugs and braced as shown on the drawings. The middle rail is in the form of a split cylinder, one half passing below and the other half above the axle. The two halves are united in front to form a pole seat and in rear to form a seat for the pintle bearing. Two lugs are provided on the axle near each axle arm. Tie-rods, two in front and two in rear, are pinned to these lugs and attached to the front and rear ends of the middle rail. The tie-rods are assembled under tension and rigidly brace the pole and pintle seat. To the front end of the middle rail is riveted the pole clamp a steel collar, 91 split on one side ana provided with a clamping bolt for drawing the two halves of the middle rail firmly about the pole. A seat for the doubletree is formed on top of the pole clamp; the doubletree bolt projects up through this seat and through the doubletree ; its upper end is threaded for a nut and braced back to the middle rail by the doubletree strap. Kiveted to the lower side of the clamp is the prop bracket, which is connected to the prop by the prop eye. When not in use this prop is swung up under the frame by a chain attached to its lower end and reaching up through the foot rest and is held in that position by hooking the free end of the chain over a button provided for the purpose. The pintle bearing is of bronze, made in halves and bored out to take the pintle shank. The two halves of the bearing, with the pintle in its seat, are assembled and held in the rear end of the middle rail by two pintle-bearing bolts. The pintle has a swiveling motion of 360 upon its shank, but is kept in its normal position by the pintle spring in the pintle bearing, which bears upon a flattened seat on the front end of the shank. The lunette is retained upon the pintle hook by a pintle latch. The latter is pivoted by the pintle-latch pin upon the end of the pintle horn and is arranged to be held in either the open or closed position by the pintle-latch spring. The latch is opened by the lunette in entering it upon the pintle hook, but must be closed by hand. The spring is peened in its seat, but may readily be driven out and a new one inserted, if required. The side rails are of channel shape, divided at the front, one branch being led forward and secured to the middle rail near the pole seat, while the other branch is utilized as a foot-rest support. The foot rest is a perforated steel plate formed to shape and riveted to the middle and side rails in front of the ammunition chest. The latter is secured to and supported by the side rails. For this pur- pose four connection lugs are riveted to and project blown ward from two chest rails on the bottom of the chest. The connections fit into four slots made in the top of the side rails and are held in place by connection pins passing through both pieces. The rear ends of the side rails project slightly beyond the chest to form steps for the use of the cannoneers in mounting. The doubletree and singletrees are formed of flange steel. The hole in the former for the doubletree bolt is bushed with a bronze nipple held in place by a steel nut, and may be replaced when worn. Two doubletree rods reach from the ends of the doubletree to the tie-rod clamps on the axle to which they are pinned. The neck yoke is now made of steel sleeves and rings. The pole is now made of steel and is prevented from turning in its seat by a pole pin. To the front end of the pole is riveted a pole plug and a neck-yoke stop. Just forward of the neck-yoke stop is 10261417 8 92 the neck-yoke counterstop, which, with its spring, is hinged to the pole body and works through a slot cut in the under side of the pole. A pole prop is hinged to the rear end of the pole and when not in use it is secured by fastenings under the limber frame and the prop- chain button on the foot rest. The ammunition chest is a rectangular steel box built up of sheet steel, formed to shape and riveted together. The front of the chest is flanged all around and riveted through the flanges to the body of the chest. The chest door is hinged at the bottom and swings down- ward and to the rear to an approximately horizontal position, where it is held by two door chains. The front of the chest and the door are strengthened by vertical corrugations pressed into the metal, those in the chest door serving as shields for the primers' of the car- tridges. The door is held in its closed positionby a shot bolt at each of the upper corners and by a chest door lock in the middle. Each shot bolt slides in a shot-bolt bracket formed of sheet steel and riveted to the door; the end of the bolt engages in an eye lug projecting from the body of the chest. The shot bolt on the right is provided with an eye, by which it may be locked by a spring padlock to a staple riveted to the door. The padlock is attached by a chain to the lock staple. The chest door lock at the middle of the door comprises a hasp hinged to the door and engaging over a cam lug riveted to the top of the chest. A spring-lock bolt in the hasp automatically secures the hasp to the cam when the former is thrown into position. Inside of the chest the cartridges are supported by three vertical diaphragms, flanged all around and riveted to the body of the chest. Each of the diaphragms is perforated with 39 flanged holes. Corresponding holes in the middle and rear diaphragms are con- nected by conical brass tubes, called connecting pieces, which are cut away on top to reduce weight. These connecting pieces support the front end of the cartridge case and enable empty cases to be carried. The rear end of the connecting piece is turned over the rear face of the flange of the perforation in the rear diaphragm, and forms a stop for the rim of the cartridge case. The chest door closes against the head of the case so that the cartridge is firmly held in position. Suitable finger clearances are cut in the flange of each cartridge hole in the rear diaphragm to enable the fingers to get a good hold on the rim of the case in withdrawing it from the chest. To the under side and front of the chest are riveted two rails to which the connections for securing the chest to the frame are fas- tened. Seats for three cannoneers are provided by a perforated metal bucket holder, riveted to and slightly raised above the chest top. The paulin issued with each limber serves as a seat cushion, and is held in place by three paulin straps suitably fastened. The watering buckets are carried in suitable compartments provided for them 93 between the seat and the chest. At each end of the seat is a handrail which projects above the top of the chest and is securely riveted to its ends. To the front of the chest are riveted a bracket for a lan- tern and fasteners for four picket-rope straps for securing two picket ropes. (One picket rope is issued for light batteries; two picket ropes are issued for horse batteries.) Fasteners are also provided on the front of the chest for three grip straps for the use of the can- noneers on the chest seat. Brackets for carrying an ax, a shovel, and pole prop are provided under the limber. The shovel is carried on the right, the ax on the left side of the middle rail, with handles to the front. The blade brackets for these implements are riveted to the bottom of the chest, the handle brackets to foot rest and lim- ber frame. The pole-prop brackets are attached to the side rails just in rear of the axle. The pickax rests in brackets on the foot rest with handle pointing to the right and lying along the rear edge of the foot rest under the lantern bracket and picket rope. The hatchet is carried in two brackets riveted to the left end of the chest. All of these implements are secured in their brackets by leather straps, which are held by strap fasteners provided for that purpose. With each limber are issued three oil cans, each of the general form of a cartridge and of a capacity of approximately two-thirds of a gallon. They are intended for hydroline, lubricating, and coal oil, and are to be carried inside the chest in the central vertical row of cartridge holes. A name plate is attached to the middle rail of each limber near the pintle seat, giving number, name of carriage, model, name of manufacturer, year of completion, and initials of inspector. In all reports and correspondence the limber should ~be designated by the number, name, etc., as given thereon. As repairs to implement at- tachments and other parts of limbers may from time to time be required, the parts needed should be referred to by the names given on the drawings or in the nomenclature of parts herein. THE 3-INCH GUN CAISSON, MODEL OF 1902. [Plates XV and XVI.] WEIGHTS. DIMENSIONS, ETC. Weight, empty, without implements and ammunition pounds 1, 424 Weight of tools and equipment carried do 84 Weight of ammunition carried do 1, 312. 5 Weight, complete, equipped and loaded do 2,820 Weight with limber, completely equipped and with 106 rounds of am- munition pounds__ 4,560 Rounds of ammunition carried number__ 70 Diameter of wheels inches 56 Width of track do 60 Free height under caisson do 22. 5 Turning angle __degrees__ 75 94 NOMENCLATURE OF PARTS. Name of part. Location, etc. Property clas- sification. Class. jSect ion. Wheels Same as on carriage . Wheel fastenings, complete do. Axle Middle-rail angle (right) Riveted to axle and side rail Middle-rail angle (left) do. Middle-rail plate Riveted to middle-rail angles Side rail (right) ' Riveted to axle lugs Side rail (left) ! do Fillerplates Riveted to side-rail flanges Pintle with bearing, complete, consisting of Pintle Seated in pintle bearing Pintle latch On pintle Pintle-latch pin, with split pin Forms pivot of latch Pintle-latch spring On pintle ~ Pintle bearing (in two parts) Rear end of middle rail Pintle spring In pintle bearing Pintle-spring pin do Pintle-bearing bolts with nuts I Secures bearing to middle rail . Name plate I Riveted near rear end of side rails.. Fuze-setter bracket rod lug | Riveted to right side rail Brake channel | Fastened to side rails Channel supports Fasten channel to side rails Cross brace Riveted to side rails Frame handle (right) Front end of side rails Frame handle (left) do Frame reinforce plate do Lunette bracket do Lunette bracket filler plate Under lunette bracket Lunette, with nut Secured in lunette bracket Caisson prop, complete On front end of side rails Consisting of Prop eye (right) Riveted to right tube Prop eye (left) Riveted to left tube Prop tubes Supports pole Prop foot Riveted to lower ends of tubes Fastening pin Through prop eyes Fastening-pin washer nut On fastening pin Fastening nut Secures prop to vehicle Prop-chain clamps I On prop tubes IV Prop chains Secured to prop Prop hook On chain i Prop-chain button Riveted into lunette bracket Prop-chain guides Riveted to cross brace Box bottom (right) Riveted to ends of brake channel . Box bottom (left) do Brake-box fillers do Brake-beam guide (right) Riveted to brake channel Brake-beam guide (left) do Front-brake brace (right) Brake channel to side rails Front-brake brace (left) do Rear-brake brace (right) do Rear-brake brace (left) do Brake beams Seated in brake boxes Brake shoes -. On end of brake beams Brake-shoe tap bolts (short) Secure shoes to beams Brake-beam pins Form pivots Brake-rod ends Connects rods to brake beams Brake rods Connect beams to cranks Including Brake-rod springs On brake rods Brake-spring covers do Brake-spring-cover heads do Brake-spring-cover ends do Brake-rod pins Secure rods to beams and cranks . Brake cranks j On brake shaft Brake-crank bolts, with nuts Clamp cranks on shaft Brake shaft, with two keys In shaft bearings on axle Brake-shaft bearings Riveted to axle lugs Brake-shaft bushings ! Brake-segment bracket Clamped on right end of axle Brake-segment bushing On brake-segment bracket Brake-segment bracket bolt, and nut i Clamps bracket to axle Brake segment I Riveted to bracket Brake-segment brace Riveted to brake segment Brake-segment guard Riveted to segment Segment rack do Front separator Between segment and guard _ . Rear separator ' do, ' NOMENCLATURE OF PARTS Continued. No. Name of part. Location, etc. Propert sffica Class. !$^ Section. 1 1 1 1 1 2 i 1 1 1 1 2 1 1 i 1 1 1 2 2 9 2 70 140 1 1 3 1 1 1 3 3 1 4 1 1 1 1 1 2 1 1 2 1 1 1 4 2 1 1 1 3 4 1 1 1 2 2 2 2 1 1 1 2 2 2 2 4 1 1 4 Rear-separator bolt Through rear separator IV Brake lever On end of shaft Brake-lever catch Riveted on brake lever Spare-pole fastening On caisson prop pin F*ast8ning nut " On spare-pole fastening Fastening washers .. . On spare pole Spare-pole bracket Riveted to middle rail . . Spare-pole rest Riveted to brake channel Pick-mattock bracket . do... Shovel-handle support Riveted to cross brace Strap fasteners for pick mattock Riveted to pick-mattock bracket and brake channel. Riveted to bottom plate Ammunition chest, complete, consisting of Top plate Bottom plate Riveted to chest rails . Rear diaphragm Riveted to chest Middle diaphragm do... Front diaphragm ... do Front-diaphragm braces (1 right, 1 left) Middle-diaphragm braces (1 right, Rear-diaphragm braces (1 right,! left) Diaphragm tees, long Riveted to front plate, front dia- phragm, and bottom plate. Riveted to front and!" middle dia- phragms, and bottom plate . Riveted to middle and rear dia- phragms, and bottom plate. Riveted to diaphragm Diaphragm tees, short Riveted to rear diaphragms Connecting pieces. Rolled into rear "and" middle dia- phragms. Soldered on connecting pieces . . Reinforce'pieces Front plate Riveted to angle 1 by 1 by 0.125 chest angle... Riveted to bo3y Chest-front braces Riveted to front plate Ax-head bracket .. do... Ax-handle support do Ax-strap fastener do Grip-strap fasteners Riveted to chest Paulin-strap fasteners do Shovel support Riveted to bottom of chest Reinforce washers Under rivet heads for pick-mattock handle support and shovel support. Pick-mattock handle support Wrench holder for spanner wrench Wrench holder for spanner wrench Riveted to left side of chest do Wrench holder for nut wrench do Wrench holder for nut wrench do Strap fasteners for wrenches Riveted to chest Chest rail (right) . . Riveted to bottom plate Chest rail (left) do .. . Filler pieces Riveted to chest body and chest rails. . Riveted to chest rails Apron latch hinge (right) Apron latch hinge (left) . do Foot rest do Handrail shanks Riveted to sides of chest Handrails Riveted to handrail shanks Door prop guide (right) Riveted to sides of chest Door prop guide (left) do Door plate Door tees Riveted to inside of door Door tees do Angle do Lock bar (right) Lock-bar hinges riveted to chest Lock bar (left) . . do Padlock chain rivets On lock bars Wing nuts Fastened to door plate Wing nut pins .... Riveted to door plate Wing nut pin washers On pins Padlock with chain and bolt snap Chain with two chain rings and bolt snap. Padlock chain staple. Attached to lock bar do Riveted to bottom plate D oor prop studs . . . Riveted to door plate Nuts. ... For studs Door props Pivoted on studs Door prop rivets Door hinge pins Fasten door plate to chest Door handle Riveted to door plate Fuze setter latch hinge do Lock bar hinges. . . Riveted to bottom plate.... 96 NOMENCLATURE OF PARTS Continued. Name of part. Location, etc. 3 ropertv cL sification. clas- Class. Section. Ammunition chest, complete, consisting of Continued. Door hinges, male Riveted to door plate Door hinges, female Riveted to top plate Apron, complete, consisting of Apron Hinged under axle E nd hinge filler pieces Riveted to apron Center hinge (right) do Center hinge (left) do End hinge (right) do End hinge (left) do Apron staple (right) j do Apron staple (left) ! do Hinge pins Secure apron to axle Hinge pins Secure apron and fuze-setter bracket to axle. Apron latches, complete Pivoted on hinges on chest rails Consisting of Hinge pins ! Attach latch body to hinge Latch bodies Latch levers Pivoted on bodies Lever pins Form pivots for levers Latch plungers , Seated in body Latch clevises Screwed on end of plunger Latch clevis pins Attach clevis to lever Latch springs In body around plunger Latch bushings Screwed into body Fuze-setter bracket ! Attached to axle brackets by apron- T v hinge pins. Consisting of Upper rod Pinned to bracket-rod lug and to lower rod. Lower rod Pinned to upper rod and to fuze-setter bracket. Fuze-setter bracket end (left) Hinged to axle bracket Fuze-setter bracket end (right) i do. Fuze-setter bracket arm (right) Riveted to fuze-setter bracket end (right). Fuze-setter bracket arm (left) Riveted to fuze-setter bracket end Pins For upper and lower rod Separator Riveted to fuze-setter bracket arms. . . . ] Staple I do ! Fuze-setter latch, complete Pinned to hinge on chest door plate . . J Consisting of Latch body I do Hinge pin j Attaches body to door plate Latch lever Pivoted on body Lever pin ! Attaches lever to body Latch plunger ! Seated in body Latch clevis ! Screwed on end of plunger Latch clevis pin ! Attaches clevis to lever Latch spring ! In body around plunger I Latch bushing j Screwed into body I NOTE. Parts of apron latches and J fuze-setter latches are not inter- changeable, and requisitions for spare parts should state specifically for which latch required. DESCRIPTION OF THE CAISSON. [Plates XV and XVI.] The caisson is made of metal throughout, with the exception of parts of the wheels. The principal parts are the wheels, axle, frame, road brakes, and ammunition chest. The wheels and wheel fastenings are interchangeable with those of the carriage and limber. The axle is similar in design, but larger in nj ^o ! o o o q \ SF* v>J X _ Caisson. JProjo -Z, unelte -Bracket frame J-fartdle -Frame Reinforce fiaie , (fross 33rice -Front. JlraJre ^S 9eeeeeG9eeeeeeeeeGeeeeeoeeo,eee o e o e eeeeQeoeeeeeeeeeeeee e 1 e e e'o.eo o eeeeeeee Q e eeeeeeeeeeeeGeeeeeeoGe Q Q O G e Q Q e 9 e e G e e G e e e G % 9 Q e 9 ' o e e e e e e e e e e 9 Q . 9 9 9 e e 9 OOOOOOOOOOOOOOOOOOOOOOOOOOOO O!O O O O oooooooooooooooooooooooooooo o'o o o o o o rw n f o . .o fPFtt Q o o i i o ~-ffa o o A.mm u toil ton (Jhest-^ ), /l-f r picfe JEails- ^-FlnUe Caisson 02. 4- 8 J2 J6 24 28 32 36 "'I i i i i i i i i i I I i i i i i i i i . fB. ff, CLASS 36 -DMSIONZ-DRAWINGI! 97 section than the limber axle, and differs from it also in the location of the lugs for the attachment of the frame and apron hinges. The frame is diamond shaped and consists principally of two steel side rails of channel section riveted to lugs on the axle and meeting in front of it at the lunette and in rear at the pintle. Opposite the front part of the wheels the two side rails are connected by a 4-inch steel channel, which forms a support for the road-brake beams. The middle rail is formed of two steel angles riveted to lugs on the lower side of the axle. In rear of the axle the middle rail braces the two side rails at the point where they meet to form the pintle seat; in front the two parts of the middle rail extend diagonally forward and are secured to the side rails at the brake channel. The pintle bearing and pintle of the caisson are in all respects sim- ilar to and interchangeable with like parts of the limber. The front ends of the side rails are brought together and securely riveted to each other and to the frame reinforce plate and the lunette bracket. To the latter a lunette, interchangeable with the one on the carriage, is assembled by the lunette nut. Two frame handles are attached to the frame at the lunette bracket. A stout cross brace of channel shape is riveted to and strengthens the side rails at the point of con- tact of the limber wheels in making short turns. A caisson prop, formed of two steel tubes united by a bronze foot, is hinged on a prop pin which passes through the side rails and lunette bracket. When not in use the prop is swung up under the spare-pole body and is held in that position by chains leading from the prop legs through guides on the cross brace and uniting in a hook which is engaged over a button riveted into the top of the lunette bracket. The caisson road brake is modeled after that of the carriage, all parts as far as possible being interchangeable. The ends of the brake channel are braced front and rear to the side rails, and on their lower side is formed a box in which the brake beams are pivoted. The brake-box bottoms project to the front and form steps for the cannoneers in mounting. The outer ends of the beams carry brake shoes attached by tap bolts; the inner ends are supported by brake- beam guides riveted to the brake channel. The front end of the brake rod is screwed into a piece, called the brake-rod end, which is pinned to the brake beam. The brake-rod spring slips over the rear end of the brake rod and abuts against a shoulder upon it. The brake spring is covered by a tube called the brake-spring cover, inclosed at each end by bronze pieces, called the brake-spring-cover head and brake-spring-cover end. The spring is compressed between the brake-spring-cover end and the shoulder on the brake rod, while the rod is arranged to have a short longitudinal movement against the pressure of the spring. The brake-spring-cover end is pinned to cranks on the brake shaft. This elastic brake rod is in all respects 98 similar to that upon the carriage, and all parts (excepting the rod proper) are interchangeable with like parts of the carriage brake. The cranks are secured on the brake shaft by clamp bolts and are keyed to prevent turning. The shaft is assembled in three bearings riveted to the axle lugs. The brake lever is mounted on the right end of the shaft, is held in place by the brake guard, and extends upward and forward in a convenient position for use by a cannoneer seated on the chest. A brake segment bracket is clamped and keyed to the axle and has riveted to it a tool steel segmental rack provided with ratchet teeth. The brake is set by engaging the brake-lever catch in the rack on this segment. The caisson ammunition chest is a rectangular steel box built up of flange steel, formed to shape and riveted together in a manner similar to the limber chest, but is larger, making provision for 70 rounds of ammunition arranged in five horizontal rows of 14 rounds each. Caissons having serial numbers 1141 to 1284 inclusive have provision for 56 rounds of ammunition only, arranged in four hori- zontal rows of 14 rounds each. The front of the chest is made of armor plate, 0.15 inch thick. A steel angle is riveted to the armor plate all around its edge, and the projecting leg of the angle riveted to the body of the chest. Three steel tees, placed vertically and riveted to the inside of the front plate, gives stiffness to the latter. Inside the chest the cartridges are supported by three vertical diaphragms flanged all around and riveted to the body of the chest. Each diaphragm is perforated with 70 flanged cartridge holes. Cor- responding holes in the middle and rear diaphragms are connected by conical brass connecting pieces, which are in all respects similar to those used in the limber chest. The diaphragms are rigidly braced to each other and to the chest front and bottom by six diaphragm braces riveted in place over the side rails. To the front and middle diaphragms are riveted vertically three long steel tees. To the rear diaphragm three long and two short steel tees are riveted. For caissons not equipped with diaphragm braces, the rear diaphragm has five steel tees. For caissons carrying only 56 rounds of ammunition three long steel tees are riveted to each dia- phragm. The chest door is made of armor plate, 0.15 inch thick. It is hinged to the body of the chest at the top by four hinges and is held closed by two lock bars hinged to the bottom of the chest. A hasp and two eccentric lugs are formed upon each of these bars; in locking the door the lugs come into contact with its lower edge, pressing it forward, while the hasp engages a wing nut on its rear face. The left lock-bar hasp has a spring padlock attached by a chain; the left bar hasp is fitted with a bolt snap which when snapped in the wing-nut eye serves to lock the hasp in position. 99 Seven steel tees are riveted to the inner face of the door. These tees are spaced so that with the door closed the vertical leg of the T falls between each alternate row of cartridges and the horizontal legs press against the heads of the cartridges. The rims of the cartridge cases are thus firmly held between the rear diaphragm and the door tees, which, in addition to forming stiffeners for the door, provide clearances between the door plate and the cartridge percus- sion cap for the protection of the latter. The lower edge of the door is also stiffened by a steel angle, running its entire length. The door opens upward to the rear, swinging through an arc of 120 to its open position, where it is held at each end by a door prop. One end of each prop runs in a door-prop guide riveted to the end of the chest; the other end of the prop is secured by a nut on a door- prop stud riveted to the door. As the door is thrown open the props catch in notches in the guides and hold it in the open position; to close the door the props must be released by hand from the guide notches. The top of the chest forms a seat for cannoneers and has a hand- rail at each end. To strap fasteners riveted to the front and top of the chest are attached three grip straps for the use of the cannoneers and three paulin straps for securing the paulin, which serves as a seat cushion. To the bottom of the chest are riveted two chest rails of channel section, which fit over and are riveted to the caisson side rails. On all caissons manufactured after November 11, 1911, and on all completely overhauled after that date, steel filler pieces and a filler plate are riveted to each side rail. On these pieces the chest rail rests, thus taking the shear strain off of the rivets in the side flanges of the chest rail and side rail. The chest rails extend to the front and are divided and bent up to support the. foot rest, a perforated sheet-metal plate formed to shape and riveted on. To the rear ends of the chest rails are riveted hinges for the apron latches, which sup- port the apron in traveling position. An apron shield, made of armor plate 0.2 inch thick (0.15 inch in later type), is hinged under the axle and arranged so as to be lowered into position in action or drawn up to clear obstructions in traveling. This apron-shield plate when lowered reaches from the. axle to within 5.5 inches of the ground and, in connection with the armored front and door of the chest, affords protection from small- arm and shrapnel fire to the ammunition servers in rear of the caisson. The caisson-apron plate, the chest door plate, and the chest front plate are made of the same quality of material as the carriage shields. For the attachment of the apron to the caisson axle four sets of hinge lugs are formed on the axle, and the apron is attached by hinges to these lugs. It is slightly convex to the front, so that when swung up for traveling it clears the spare pole carried 100 under the caisson frame. For traveling, the apron is drawn up to the rear, as stated, and is held by two apron latches. Each apron latch consists principally of a latch body, lever, plunger, and spring. The apron-latch body is supported by a hinge pin passing through the apron-latch hinge riveted to the rear end of the chest rail ; the lower end of the latch body terminates in a hook, which engages the latch staple riveted to the apron shield and holds the latter in traveling position. To prevent accidental disengage- ment of hook from staple, the opening of the hook is closed by a plunger seated in the latch body and pressed outward into action by a coiled spring. An apron-latch lever is provided for withdrawing the plunger from the hook when it is desired to disengage the hook from the staple. The fuze-setter bracket consists of two angle irons, pivoted at the front upon the two apron-hinge pins on the right side of the caisson and united at the rear to form a seat, to which the fuze setter is securely bolted. A staple is riveted to the bracket near its lower end, and a fuze-setter latch pivoted upon a hinge or support on the chest door is arranged to engage this staple and hold the bracket with fuze setter in traveling position. For use, the fuze setter with bracket is swung down and supported by a jointed rod extending from the lower end of the bracket to the right side rail. This jointed rod or brace consists of upper and lower rods pinned together; the upper rod is also pinned to the bracket-rod lug on the side rail and the lower rod to the bracket itself. This flexible connection enables the rod to fold up when the bracket is swung up for traveling. The fuze-setter latch is of the same general design as the caisson- apron latch described above, but the parts of the two latches are not interchangeable. The fuze-setter latch body is attached by a hinge pin to a hinge riveted to the rear face of the chest door. For batteries equipped with wooden poles, a spare-pole body is carried under the caisson frame on each of four caissons. The small end of the pole rests in a leather-covered bracket called the spare-pole bracket, which is riveted to the middle rail directly under the axle; the large end is held in place by the spare-pole fastening, a swing- ing bolt, the upper end of which is located in the lunette bracket and held in place by the fastening pin ; near the center of the pole a third point of support, the spare-pole rest, which is riveted to the brake channel, holds the pole rigidly in place. A long-handled shovel is carried, with the blade resting in the shovel support, riv- eted to the bottom of the chest, and with the handle supported by the shovel-handle support, attached to the frame cross brace. The pick-mattock head is held by a bracket riveted on the brake channel. The handle projects to the rear through a pick-mattock handle bracket riveted to the bottom of the chest. The ax is carried in 101 brackets riveted to the front and the twoVreiicHes in bVacke'ts riv- eted to the left end of the chest. All of these implements are se- cured in their brackets by leather straps, engaging in strap fasteners riveted to various parts of the caisson. A name plate is attached to each caisson near the pintle, giving the number, name of carriage, model, name of manufaturer, year of completion, and initials of inspector. In all reports and corre- spondence the caisson should be designated by the number, name, model, etc., given on this name plate. In requests for spare parts for repairs, etc., the parts should be asked for by the names given on the plates or in the paragraph giving nomenclature of parts in this handbook. THE 3-INCH GUN CAISSON LIMBER, MODEL OF 1916. [Plates XVII and XVIII. ] WEIGHTS, DIMENSIONS, ETC. Weight complete, empty pounds 987 Weight of tools and equipment carried (oil cans filled) do 113 Weight of ammunition carried do 675 Weight, completely equipped and loaded do 1, 775 Weight of gun, carriage, model of 1902, and limber, model of 1916, com- pletely equipped and with 40 rounds of ammunition pounds 4, 295 Rounds of ammunition carried in limber chest number 36 Diameter of wheels - inches 56 Width of track do 60 Free height under limber (carriage, model of 1902=22) do 24 Turning angle with carriage, model of 1902 degrees 80 Turning angle with caisson do 81 NOTE. The 3-inch gun carriage, model of 1916, will not be used with the 3-inch gun limber, model of 1902, or the 3-inch caisson limber, model of 1916, on account of the excessive weight of the 1916 gun carriage. A special carriage limber will be provided for the 1916 carriage. NOMENCLATURE OF PARTS. [Parts not enumerated in the following list are the same as those for the 3-inch gun limber, model of 1902. No. Name of part. Location, etc. Property clas- sification. Class. Section. Middle rail (upper and lower half) Riveted to chest bottom Consisting of Doubletree bolt In top of pole clamp Doubletree nut On doubletree bolt Doubletree strap ! Riveted to middle rail Pole clamp ' do Pole clamp bolt In pole clamp Pole clamp nut On pole clamp bolt Pole pin Secures pole in seat Pole pin reinforce plate Riveted to middle rail at pin. . Pole stop ; Riveted in middle rail Prop bracket i Riveted to pole clamp Axle bracket, right : Clamped to axle, right end Axle bracket, left Clamped to axle, left end Side rail,right Riveted to axle bracket, right . Side rail, left i Riveted to axle bracket, left... IV 102 NOMENCLATURE OF PAKTS Continued. No. Name of part. Location, etc. Name plate.. Limber prop. Consisting of Prop chain Prop chain fastening. Prop chain handle. . . Prop eye Prop foot Prop tube Front tie rod, right Front tie rod, left Rear tie rod, right Rear tie rod, left Tie rod pins Doubletree rods Chains, doubletree rod . . . Foot rest Consisting of Riveted to middle rail near pintle Assembled to middle rail by means of prop bracket Property clas- sification. Class. Section. Fastened to prop tube. . Riveted to prop tube. . . On free end of chain In top end of prop tube. In lower end of tube. Hinged to pole clamp by prop eye. Ties middle rail and axle bracket. . ...do .do. .do. Fasten ends of tie rods From doubletree to axle brackets.. Foot-rest plates. ifor< Hole reinforce Pick handle fastener. ..I..'..'..'..'.'.'.'.'... Pick-mattock point guard Pole prop pocket Pole prop support Prop chain button Prop chain button rivet Shovel handle support Strap fastener No. 1 Strap fastener No. 2 Pintle with bearing, complete Consisting of: Guide bolt Lock plates Pintle ;... Pintle bearing Pintle bearing bolts Pintle bearing guide Pintle bearing spring Pintle latch Pintle latch pin Pintle latch spring Pintle nut Pole supporting spring Sleeve Spring rod Spring rod nut Spring rod pin Trunnion bolts Pole cjmplete, consisting of: Butt reinforce Neck yoke chafing plate Neck yoke counter stop Neck yoke counter stop pin Neck yoke counter stop spring Neck yoke stop Pole body Pole plug Pole pin bushing Ammunition chest, complete, consisting of: Ammunition chest connecting pieces . . Axe handle support Axe head fastener Bottom plate, right Bottom plate, left Bucket holder Bucket holder transoms, right. Bucket holder transoms, left. . Chains, door Chains, No. 11 Diaphragm reinforces Door Door chain fasteners Door frame Door hinges, male Door hinges, female Riveted to side rails. Riveted to front of foot rest Riveted to foot rest at prop chain Riveted on foot rest Riveted to foot rest ...do... .do. .do. .do. Riveted under foot rest... For pick-ax strap At rear end of middle rail . In middle rail behind axle Lock trunnion and pintle bearing bolts Seated in pintle bearing Pivoted in guide Bolt guide to middle rail In rear end of middle rail In pintle bearing On pintle Pins latch to pintle On pintle On pintle shank Around spring rod On pintle shank In middle rail behind axle On spring rod Pivots spring rod to pintle bearing In pintle bearing guide On rear end of pole... On pole at neck yoke. At front end of pole . . ..do. .do. .do. Seated in front end of middle rail In front end of pole In pole body at pin Rolled . into rear and middle dia- phragms. Riveted to right side of chest .do. Forms part of chest bottom do Riveted to bucket holder transoms Riveted to top of chest .do. Fastened to door and handrail shanks.; Fastened to door Riveted to diaphragms at side rails Forms back of chest \ Riveted to door ....do ....do Riveted to bottom of chest IV CD a: si -- UJ s rO 103 NOMENCLATURE OF PARTS Continued. No. Name of part. Location, etc. Property clas- sification. Class. Section. 4 1 1 1 1 1 1 1 1 2 1 1 1 1 2 2 2 2 1 2 2 78 4 16 3 3 1 2 2 2 2 2 Ammunition chest, complete, consisting of Continued. Door hinge pins In hinges IV 3 Front diaphragm . Inside chest . ... Front plate Forms front of chest Front transom, right Riveted to diaphragms Front transom, left do Hand rail forward bracket, right Riveted to side of chest . . Hand rail forward bracket, left ....do Hand rail rear bracket, right do Hand rail rear bracket left do Hand rail tubes Riveted to hand rail brackets Hatchet blade bracket Riveted to left side of chest Hatchet handle fastener ....do Lantern bracket body Riveted to front plate Lantern bracket bottom Riveted to bracket body Lantern strap fasteners do Lock bars Hinged in lock bar bearings Lock bar bearings, right Riveted to top plate Lock bar bearings, left ... do Middle diaphragm Inside chest Middle transoms, right Riveted to diaphragms Middle transoms, left .. do Padlock, No. 850. Chained to door Pick guard, chisel point Riveted to left side of chest Rear diaphragm Inside chest Rear transom, inner, right Riveted to diaphragms Rear transom, inner, left do .... Rear transom, outer, right do Rear transom, outer left do Reinforce pieces Soldered to connecting pieces For axe and paulin straps Strap fasteners, No. 1 . Strap fasteners, No 5 For blanket and picket rope straps For grip and paulin straps Strap fasteners, No. 7 Strap fasteners, No. 12 For hatchet and shovel straps Top plate Top plate front fillers.. . Riveted to side rails Top plate rear fillers do Wing nuts Wing nut pins Riveted to door plate Wing nut pin washers On wing nut pins DESCRIPTION OF THE 3-INCH GUN CAISSON LIMBER, MODEL OF 1916. [Plates XVII and XVIII.] As in the 3-inch gun limber, model of 1902, the model of 1916 limber is of metal throughout, excepting the spokes and felloes of the wheels. The principal parts of the limber are the wheels, axle, frame, ammunition chest, pole, doubletree, singletrees, and neck yoke. Of these parts all are the same as described for the earlier model of limber except the frame and ammunition chest. The frame consists of a middle and two side rails. The middle rail is in the form of a split cylinder, one half passing below and the other half above the axle. The two halves are united in front to form a pole seat and in rear to form a seat for the pintle-bearing guide. Two axle brackets are clamped about the axle near the axle arms with two bolts each, and are provided with lugs. Tie rods, two in front and two in rear, are pinned to these lugs and attached to the front and rear ends of the middle rail, thus rigidly bracing the pole and pintle seat. To the front end of the middle rail is 102614 17 n 104 riveted the pole clamp, a steel collar, split on one side and provided with a clamping bolt for drawing the two halves of the middle rail firmly about the pole. A seat for the doubletree is formed on top of the pole clamp; the doubletree bolt projects up through this seat and through the doubletree; its upper end is threaded for a nut and is braced back to the middle rail by a doubletree strap. Riveted to the lower side of the pole clamp is the prop bracket, which is connected to the prop, a steel tube provided with a bronze foot, by the prop eye. When not in use, this prop is swung up under the frame by a chain, which is attached to the lower end of the tube by a prop-chain fastening, and reaches up through the foot rest, where it terminates in a prop-chain handle. It is held in the raised position by hooking the handle over a prop-chain button provided on the foot rest for that purpose. When limbered up with another vehicle, this limber has in its pintle and pintle bearing an automatic pole support. The pintle hook has a lug formed on its lower side, which projects backward and bears against the underside of the lunette on the drawn vehicle, thus preventing the vertical rotation of the pintle. The pintle- bearing guide is a steel yoke fixed in the rear end of the middle rail. The pintle bearing is of bronze, pivoted to the guide by two trunnion bolts; it is bored out to receive the shank of the pintle and is counter- bored in front for the pintle-bearing spring. The latter, assembled about a sleeve fitting over the pintle shank, is compressed between a pintle nut and the pintle bearing, and absorbs the shock of starting. The sleeve checks the movement of the pintle nut before the spring becomes compressed solid. On top of the pintle bearing is formed a lug, to which is pinned one end of a spring rod, the other end of which is threaded for a spring rod nut and slotted to receive a guide bolt that passes through the middle rail near the axle. This spring rod, guided in the rear by a vertical wall of the pintle-bearing guide, through which it passes, and in the front by the guide bolt through the slot, as stated, is drawn backward by the relative action of the pintle bearing on its trunnions, and in doing so compresses the pole- supporting spring, which is assembled about it, between the spring rod nut and the vertical wall of the pintle-bearing guide. When the limber pole is dropped, the pintle tends to rise. Being held down, however, by the lunette in it, the pintle bearing is forced to swing on its trunnion bolts and draw the spring rod backward, thus com- pressing the pole-supporting spring until the reaction of the spring is sufficient to support the pole. The pintle has a swiveling motion of 360 upon its shank. The lunette of the drawn vehicle is retained upon the pintle hook by a pintle latch. The latter is pivoted upon the end of the pintle 105 horn and is arranged to be held in either the open or closed position by the pintle latch spring. The latch is opened by the entering lunette but must be closed by hand. The spring is peened in its seat but may readily be driven out and a new. one inserted if required. The side rails are of channel shape, fitting down over the axle brackets and riveted thereto. The rear ends project slightly be- hind the chest to form steps for the use of cannoneers in mount- ing; the front ends are bent up to support the foot rest. To the middle portions are riveted the chest, which they support, and of which they form a part of the bottom. The foot rest is a perfo- rated sheet of flange steel formed to shape and riveted to the side rails. The ammunition chest is a rectangular steel box built up of sheet steel, formed to shape and riveted together. The front plate is flanged all around and is riveted through the flanges to the top plate, which forms the top, sides, and part of the bottom of the chest. The remainder of the bottom is formed by two bottom plates and by the side rails. The door is made of a steel plate riveted to a frame, which consists of a steel angle around the top and sides of the plate welded to a flat steel bar along the bot- tom edge of the plate. The door is hinged at the bottom and swings downward and to the rear to an approximately horizontal position, where it is held by two door chains, attached to the handrail shanks, and to the door by door-chain fasteners. The front plate and the door of the chest are strengthened by vertical corrugations pressed into the metal, those in the chest door serving as shields for the primers of the cartridges. The door is held in its closed position by two lock bars, each hinged in two lock-bar bearings riveted to the top of the chest. A hasp and two eccentric lugs are formed upon each of these bars; in locking the door the lugs come into contact with the projecting leg of the upper door angle, pressing it inward, while the hasp engages a wing nut riveted to the door plate. The right lock-bar hasp has a spring padlock and a bolt snap attached by a chain to the door; the left one is fitted only with the bolt snap," which, when snapped in the wing-nut eye, serves to lock the hasp in position. A door handle is also riveted to the right side of the door plate. Inside the chest the cartridges are supported by three vertical dia- phragms, flanged all around and riveted to the body of the chest. Each diaphragm is perforated with 39 flanged holes. BetAveen the diaphragms^ riveted to them and supporting them, are 10 vertical plates called transoms, the lower ends of which are riveted to the middle and side rails. Other than as described the interior of the chest is the same as in the limber model of 1902. 106 On top of the chest, seats for three cannoneers are provided by a perforated sheet-metal bucket holder, supported by four bucket- holder transoms. The watering buckets are carried in the compart- ments thus provided for them between the seat and the chest. The paulin issued with each limber serves as a seat cushion, and is held in place by three paulin straps attached to strap fasteners, which are riveted to the bucket holder and the front of the chest. At each side of the seat is a handrail, which projects above the top of the chest, and which is riveted to the sides of the chest by means of handrail shanks. In strap fasteners riveted to the top of the chest behind the bucket holder are four blanket straps. To the front plate of the chest are riveted a bracket for a lantern and fasteners for four picket-rope straps that secure two picket- ropes. To the paulin- strap fasteners riveted to the front of the chest are also attached three grip straps for the use of cannoneers on the chest seat. Under the foot rest is riveted a shovel handle support and under the chest are strap fasteners for a shovel-blade strap, which carry a short-handled shovel. On the right side of the chest are riveted an ax-head fastener., an ax-handle support, and a strap fastener, for carrying an ax, the handle to the front. On the left side of the chest are riveted a hatchet-blade bracket, a hatchet-handle fastener, and a strap fastener for securing a hatchet. Riveted to the foot rest are a pick-head fastener, a pick-handle fastener, a pick- mattock point guard, a pole-prop support, a pole-prop pocket, and the necessary strap fasteners for carrying a pickax and a pole prop. The head of the pickax projects slightly over the left side of the foot res^ and the ax end is supported by a pick guard, chisel end, riveted to the left side of the chest. The pole prop is the shape of a pair of tongs and is used to prop up the end of the pole to relieve the horses of the weight on the neck yoke. With each limber are issued three oil cans, each of the general form of a cartridge and of a capacity of approximately two-thirds of a gallon. They are intended for hydroline, lubricating, and coal oil, and are to be carried inside the chest in the central vertical row of cartridge holes. A name plate is riveted to the middle rail of each limber near the pintle seat, giving number, name of limber, model, name of manufac- turer, year of completion, and initials of inspector. In all reports and correspondence the limber should ~be designated l>y the number, name, etc., as given on the name plate. As repairs to implement attachments and other parts of the limber may from time to time be required, the parts needed should be referred to by the names given on the drawings or in the nomenclature of parts. 107 THE 3-INCH GUN CAISSON, MODEL OF 1916. [Plates XIX, XX, and XXI.] WEIGHTS, DIMENSIONS, ETC. Weight empty, without implements and ammunition.. pounds 1, 384 Weight of tools and equipment carried do 53. 5 Weight of ammunition carried do 1, 312. 5 Weight, completely equipped and loaded do 2, 750 Weight with limber, completely equipped and with 106 rounds of am- munition pounds 4, 525 Rounds of ammunition carried number 70 Diameter of wheels inches 56 Width of track do 60 Free height under caisson do 21 Turning angle degrees 81 NOMENCLATURE OF PARTS. [Parts not enumerated in the following list are the same as those for the 3-inch gun caisson, model of 1902.] No. Name of part. Location, etc. P H5S- Class. Section. 1 1 2 2 2 2 2 2 2 16 Middle rail, complete Riveted to bottom of chest IV 3 Consisting of Apron-hinge Ing, center Piveted to middle rail . . Chain-guide pins At wheel guards End reinforces On front end of middle rail Frame handle, right ... Riveted to front end of middle rail .... do Frame handle, left Fuze-setter bracket lug, inner. . r iveted to middle rail Lunette, with nut and lock washer Lunette bracket Secured in lunette bracket T\ iveted to front end of middle rail .... Riveted to bottom of chest Middle rail ris;ht Middle rail, left . do.. Middle-rail top plate. . . T iveted to middle rails Middle-rail transom Braces middle rail at wheel guards .... On middle-rail top cover plate Name plate Prop cnain guides R iveted to middle rail Prop-chain button Shovel-blade bracket. . . . R iveted to middle rail Tie-rod sleeve Covers front tie-rod bolt Wheel guards T iveted to middle rail Tie rods.. . . ... Bolted to middle and side rails Side rails complete Consisting of Apron-lunge lugs, end Axle brackets Clamped on axle Belleville springs On spring rods below axle brackets T> iveted to right side rail Brake crank-shaft bearing, right Brake crank-shaft bearing, left Riveted to left side rail Caisson-carrying springs On spring bolts in side rails . . Fuze-setter bracket lug, outer. . Riveted to side rail left Side rail, right. Rides on axle bracket Side rail, left do Side-rail liners Riveted to side rails Spring bolts Spi ing-bolt nuts On ends of rear spring bolts Pintle, with bearing complete Hear end of middle rail . . Consisting of Pintle.... Seated in pintle bearing Pintle bearing Rear end of middle rail Pintle bearing bolts, with nuts. . . Bolt pintle bearing to middle rail On pintle Pintle latch Pintle-latch spring . . do Pintle spring Pintie spring seat do Spring plunger do Pin, type A .. Pivots latch to pintle ... 108 NOMENCLATURE OF PARTS Continued. Name of part. Location, etc. Property clas- sification. Class. Section. Caisson prop, complete On front end of middle rail IV 3 Consisting of Sp.cn red to nron Prop-chain clamps On prop tubes Prop eye right j Riveted to right tube Prop eye left Riveted to left tube Prop foot In lower ends of tubes On chain . . . Prop tubes Support middle rail Pins prop eves to middle rail Washer nut On fastening pin Ammunition chest, complete, consisting of Ammunition-chest connecting pieces. . Axe handle supports Connect rear and middle diaphragm perforations. Riveted to chest back Axe head bracket do . . Chains No. 11 Fasten bolt snaps to door j Chest angle Riveted to chest back and body. .. . 1 Chest back Forms back of chest 1 Chest top Forms top and sides of chest Diaphragm reinforces . Support diaphragms over side rails Hinged to top of chest in front Door Door angle Riveted to lower edge of door inside. . . Riveted to door Door handle Door hinges male do Door hinges female Riveted to top of chest Door hinge pins Pin male to female hinges Door prop Holds door open Door-prop guide right On left side of chest Connects prop to guide Door-prop stud Fastens prop to door Door tees Riveted on inside of door Front diaphragm Riveted in chest Front transom inner right Braces diaphragms to middle rail . . Front transom' inner left do Front transom outer right Braces diaphragms to side rail Front transom outer, left do . . . Handrails Riveted to handrail shanks . . . Handrail shanks Riveted to sides of chest Intermediate bottom plate right Forms part of chest bottom do Lock bars In lock-bar hinges Lock-bar hinges Riveted to chest door Riveted in chest Middle transoms left do Forms part of chest bottom . . *. do Padlock No 8oO Chained to door Riveted to side of chest Rear diaphragm Riveted in chest Rear transom, outer, right Rear transom outer left Riveted to diaphragms . do . Rear transom inner right do do Soldered on connecting pieces Reinforce washers Under door prop guide rivets Riveted on chest Wing nut pins Fasten wing nuts to door Wing nut pin washers Under wing nut pins Riveted to chest back Foot rest complete Riveted to middle rail" and chest Consisting of On right side of foot rest On left side of foot rest Apron latch base reinforces On apron latch bases Foot rest Riveted to middle rail and chest Braces foot rest to side of chest Foot rest brace, right Foot rest brace left do Foot rest corner brace Braces rear left corner of foot rest Riveted to foot rest at brace Foot rest reinforce left do Fuze setter latch base Riveted to front of foot rest Lock bar stons... Riveted on foot rest. . . iltfin CD O) LUNETTE mop FOOT- CAISSON mop -BRAKE 3HA/T -DOOR PROP -56 WHEEL -FOOT REST BRACE -FOOT REST FUZE, SETTER LATCH HANDLE PAULIN STRAP- BRAKE BAND BODY BRAKE BAND CLIP DOOR HIM6E , 1 i SEGMENT GUARD -, ] | LEVER CATCH--, ! i LEVER--, I i ; o o o o o o jo o oo o o o o o o o o o oj o oolooooooooooooj oooooo;oooooooooooooo'Ooo!oooooooooooo ooooooioooooooooooooc'ooolooooooooooool oooooo;oooooooooooooo!ooo|ooooooooooo.o oo o o o o 10 o o o o o o o o o o o o o! o o o; o e o o o o o o o o 0.0 oo oooo|oooooooooocooo'oooioooooooo"oo ojo oo o o o o jo o o o o o o o o o o o o o! o o o| o o o o o o o o o o oo o o Q-p o OjO o o o o ckp ooooooo'oo ojxj o o o o o o o g-p o o I > O Cfo d> O /^: AMMUNITIOM CHEST > ', AXE HANDLE SUPPORT ! PICK-MATTOCK STRAP PICK-MATTOCK BRACKET PICK-MATTOCK AH* JJO BRACKET--' i -AXE STRAP AXE HANDLE TIE ROO --MIDDLE RAIL PINTLE LATCH SPRIH6 PINTLE LATCH PINTLE 3 INCH GUN CAI550N MODEL OF 1916 PLAN 109 NOMENCLATURE OF PARTS-Continued. No. Name of part. Location, etc. Property clas- sification. Class. Section. 1 2 2 4 4 2 4 2 !} ' 2 ij i i 6 f 2 4 r 2 f{ 2 i 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Band brake, complete, consisting of \djusting links Pinned to brake band ends IV 3 Pinned to brake shafts Band clips . . Riveted to brake hangers Band guides Riveted to brake band bodies Brake band bodies Around brake drums Brake band ends Riveted to brake band bodies Brake band linings Inside brake band bodies Keyed to brake crank shaft . . Brake crank shaft In bearings on side rails Brake drums Bolted to wheels at hubs Brake hanger right Clamped to axle, right end Brake hanger left Clamped to axle left end . . Brake lever On right end of brake lever shaft Brake-lever catch On lever . . . In bearing and in crank shaft Brake-lever shaft bearing Bolted to chest and foot rest . . Brake pins Pin brake-band ends to brake shaft. . . Connect brake cranks and cranks, outer. On brake rods Brake rods Brake-rod ends Brake shafts Supported bv brake hangers Cranks, outer Fixed on brake shafts Segment guard Riveted to chest side and foot rest do Segment rack Separators Separate guard and rack Apron, complete . Hinged under chest ... . . Consisting of Apron Pinned to hinge lugs Apron hinges Riveted on apron *" Apron-latch staples do Apron latches, complete Consisting of Latch bodies . Pivoted on bases on foot rest Pinned to bases .. Latch springs In body around plunger Latch handles Pivoted on bodies Plungers Seated in bodies Pins, type A Pin bodies to bases Pins, type A Pin handles to bodies Fuze-setter bracket, complete Hinged to middle and side rails Consisting of Fuze-setter bracket arm right Riveted to bracket end right Fuze-setter bracket arm left Riveted to bracket end, left Fuze-setter bracket end right Pinned to lug inner Fuze-setter bracket end' left Fuze-setter bracket separator Between ends' of bracket arms . . Fuze-setter rod lower Pinned to bracket separator Fuze-setter rod, upper Pinned to latch base Fuze-setter latch complete Pivoted on base on foot rest Consisting of Latch body Pinned to base Latch spring In body around plunger Latch handle .... Pivoted on body Plunger. . Seated in body Pin type A Pin, type A ... Pins handle to body DESCRIPTION OF THE 3-INCH GUN CAISSON, MODEL OF 1916. [Plates XIX, XX, and XXI.] As in the 3-inch gun caisson, model of 1902, the model of 1916 caisson is made of metal throughout, with the exception of the fel- loes and spokes of the wheels. The principal parts of the caisson are the wheels, axle, frame, brakes, and ammunition chest. The wheels and wheel fastenings are interchangeable with those of the carriage and limber. The axle is similar in design and equal in cross section to the limber axle, but differs from it in the size and location of the lugs for the axle brackets and in the lugs for the brake hangers. 110 The frame consists principally of two side rails and a middle rail, braced by two tie rods and also by the ammunition chest, to which they are riveted, and of which they form a part of the bottom. The tie rods, one on each side of the middle rail, are bolted at their ends to the middle rail, opposite the front and rear parts of the wheels, and to the side rails near the axle. The middle rail is made of two pressed steel channels connected by a top cover plate, with the flanges overlapping in the rear to form a pintle seat, the front ends being securely riveted tq a lunette bracket. In the latter a lunette is assembled by a lunette nut. The side rails are of cast steel, the length of the chest. Each has two pairs of vertical guides that straddle the axle, fitted with bronze liners in which the axle bracket slides. Above and between these liners the side rail is bored out and tapped for the spring rod and counterbored for the caisson carrying spring. Clamped to the axle at each side rail with two fillister-head screws is an axle bracket, upon which are formed two lugs, bored out for the spring rod and coun- terbored for the caisson carrying spring. These lugs slide up and down between the side rail liners and hold the chest from lateral and longitudinal motion with respect to the axle. The four caisson carrying springs, assembled upon spring rods, are compressed be- tween these lugs and the side rail, thus supporting the chest on the axle and allowing it 0.75 inch of movement. The upper end of each spring rod is screwed into the threaded portion of the side rail, where it is prevented from turning by a rivet ; the lower end extends below the axle bracket lugs, where there are assembled upon it four Belleville springs, rings of flat spring steel, cupped to give them a slight spring action, held in place by a nut on the lower end of the rod. When the caisson is traveling over rough road the rebound of the chest from the caisson carrying springs is met by the action of the Belleville springs, which are compressed between the spring rod nuts and the axle bracket lugs, a maximum upward spring motion of 0.25 inch being thus available. The nuts on the .two front spring rods are made to serve as and are called apron hinge lugs, end. To these two lugs are pinned the end apron hinges. An apron hinge lug, center, made of flange steel and riveted to the middle rail, supports the remaining two of the four hinges by which the apron is hung. The apron itself is made of armor plate 0.15 inch thick and may be lowered into posi- tion in action or swung up to clear obstructions in traveling. When lowered it reaches from the axle to within 4.5 inches from the ground, and, in connection with the armored back and door of the chest, affords protection from small-arm and shrapnel fire to the ammuni- tion servers in rear of the caisson. The apron, chest door, and chest back are made of the same quality of material as the carriage Ill shields. For traveling, the apron is drawn up to the front and held by two apron latches. Each apron latch consists principally of a latch body, handle, plunger, and spring. The apron latch body is pinned to an apron latch base riveted to the side of the foot rest; the lower end of the latch body terminates in a hook, which engages an apron latch staple riveted to the apron and holds the latter in traveling position. To retain the staple in the hook, the opening of the hook is closed by a plunger seated in the latch body and pressed outward into action by a coiled spring. By pressing the apron latch handle down with the hand, the plunger is first withdrawn from the hook, and then the hook is pushed backward, disengaging it from the apron latch staple. The pintle bearing is of bronze, bored out to take the pintle shank, and is held in place by two bolts through the middle rail. The pintle has a swiveling motion of 360 upon its shank, but is kept in its normal position by the pintle spring in the pintle bearing, which presses a spring plunger against a flattened seat on the shank. The lunette of the drawn vehicle is retained upon the pintle hook by a pintle latch, which is pivoted by a pin upon the end of the pintle horn and is held in either the open or the closed position by the pintle-latch spring. Both the pintle latch and the pintle-latch spring are interchangeable with those on the limber. The latch is opened by the entering lunette, but must be closed by hand. The spring is peened in its seat, but may readily be driven out and a new one inserted, if desired. Near the front end of the middle rail and riveted thereto are two frame handles and two wheel guards, the purpose of the latter being to present a wearing surface against which the limber wheels may rub in turning short, thus saving damage to the middle rail. Between the wheel guards, inside the middle rail, which it braces, is a stiffener called a middle-rail transom. A caisson prop, formed of two steel tubes united by a bronze foot, is hinged on a prop pin which passes through the middle rail and lunette bracket. When not in use, the prop is swung up against the middle rail and is held in that position by chains leading from the prop legs through guides on the middle rail, and uniting in a hook, which is engaged over a button riveted to the middle-rail top cover plate. The caisson band brake is similar to that on the 3-inch gun car- riage, model of 1916, and on the two vehicles the brake drum, brake-band lining, brake-band end, band clip, band guide, adjusting nut, and adjusting link are interchangeable. The brake-band bodies differ only in the placing of rivet holes for the band guides. Bolted to the hub of each wheel, and revolving with it, is a brake drum of cast iron, shaped somewhat like a pulley, about the periphery 112 of which is a brake band, consisting of a steel band comprising about nine-tenths of a complete circumference, and lined with a strip of Raybestos or equivalent material. The brake-band ends, each with a pair of jaws formed on it, are riveted to the terminals of the brake band. To prevent the band from shifting or slipping off the drum, two small blocks, called brake-band guides, are riveted to the band body and work in brake-band clips. These are bronze castings radial from the axle, and are riveted to a brake hanger. The latter is a strut with a collar formed on one end, which is clamped on the axle by a bolt ; the other end carries the brake shaft. On the outer end of the brake shaft is formed a crank, one arm of which is pinned in the jaws of the upper brake-band end, while the other arm is connected to the lower brake-band end by an adjust- ing nut and link, which may be shortened or lengthened by screwing the nut in or out of the link. The inner end of the brake shaft is made square and carries the crank, outer, which is connected to the brake crank by a brake rod with two adjustable brake-rod ends. The two brake cranks are actuated by a brake-crank shaft, one of them being integral with it, the other being assembled to it by two feathers and a pin. The ends of the crank shaft are supported just inside the cranks by brake-crank shaft bearings, riveted to the side rails; the middle receives support from the flanged holes in the middle rail through which it passes. Assembled in the brake-crank shaft, which is tubular and has two diametrically opposite slots cut its entire length, is a solid brake-lever shaft, feathered only a few inches at its inner end, which extends to the middle of the crank shaft. Thus the torsional force in the lever shaft is transmitted to the crank shaft at the middle, thereby equalizing the effect on the two cranks. The brake-lever shaft, square on the right end to receive the brake lever, has its outer bearing in a triangular brake-lever shaft bearing, which is bolted to the chest side, the bottom plate, outer, and the foot rest; the inner end is carried in the crank shaft, as stated. The brake lever is placed convenient to the cannoneer riding on the right side, as it is just in front and to the right of the chest, extending forward and upward from the end of the brake-lever shaft. It has an angular travel of about 60. For holding it in any set position, it carries a brake-lever catch, riveted near the lower end, which engages in the teeth of a segment rack, which, together with a similar quadrant of flange steel, called a segment guard, is riveted to the side of the chest and the foot rest. The rack and the tooth of the catch are case-hardened. Two separators at the ends of the segment hold the rack and the guard sufficiently apart for the lever to work between them. When the brake lever is pulled up to a set position, the torsion produced in the brake-lever shaft is communicated to the brake- 113 crank shaft, and through' it to the brake cranks. These, in turning, pull forward the cranks, outer, by means of the brake rods. The cranks, outer, turn the brake shafts, which, by means of the crank arms on their outer ends, draw the terminals of the brake bands closer together, clamping them tighter upon the revolving brake drums, and the resulting friction retards the rotation of the wheels. The caisson ammunition chest is a rectangular steel box built up of flange steel, formed to shape and riveted together in a manner simi- lar to the limber chest, but is larger, making provision for TO rounds of ammunition arranged in 5 horizontal rows of 14 rounds each. The top and sides of the chest are comprised in one piece of flange steel, and the bottom is made up of four pieces, two outside the side rails, and two between the middle and side rails, called outer bottom plates, and intermediate bottom plates, respectively. The back of the chest is made of armor plate 0.15 inch thick. A steel angle is riveted to the armor plate all around its edge, and the projecting leg of the angle is riveted to the body of the chest. Inside the chest the cartridges are supported by three vertical diaphragms, flanged all around and riveted to the body of the chest. Each diaphragm is perforated with 70 flanged cartridge holes. Cor- responding holes in the front and middle diaphragms are connected by cylindrical brass connecting pieces similar in all respects to those used in the limber chest. The diaphragms are rigidly braced to each other and to the caisson frame by 12 transoms, which are securely riveted to the diaphragms, the middle and side rails, and also to the chest back, which they serve to stiffen. Riveted to the bottom of the rear and middle diaphragms and to the top of the side rails are four diaphragm reinforces made of flange steel angle, which help to transmit the load from the diaphragms to the side rails. The chest door is made of armor plate 0.15 inch thick. It is hinged to the body of the chest at the top by four hinges, at each of which, inside the chest, is a hinge reinforce riveted to the chest top and middle and front diaphragms. The door is held closed by two lock bars hinged to the bottom of the door. A hasp and two eccentric lugs are formed upon each of these bars; in locking the door these lugs bear against an equal number of lock-bar stops riveted to the foot rest, thus pressing the door shut, while the hasp engages a wing nut higher up on the door. The right lock bar may be locked in po- sition either by a spring padlock or a bolt snap, both of which are fastened by a chain to the door near the wing nut and engage in the eye of the latter ; the left lock bar has only the bolt snap so attached. Seven steel tees are riveted to the inner face of the door. These tees are spaced so that with the door closed the vertical leg of a T falls between each alternate row of cartridges, and the horizontal 10261417 10 114 legs press against the heads of the cartridges. The rims of the car- tridge cases are thus firmly held between the front diaphragm and the door tees, which, in addition to forming stiffeners for the door, provide clearances between the door plate and the cartridge percus- sion cap, for the protection of the latter. The lower edge of the door is also stiffened by a steel angle running its entire length. The door opens upward and forward, swinging through an arc of 120 to its open position, where it is held by a door prop on the left side of the chest. One end of the prop is secured with a nut on a door-prop stud riveted to the door; the other end runs in a door- prop guide riveted to the side of the chest. As the door is thrown open, the props catch in notches in the guides and hold it in the open position ; to close the door the props must be released by hand from the guide notches. A door handle is riveted in the middle of the door at its lower edge. The top of the chest forms a seat for cannoneers and has a hand- rail at each side. To one set of strap fasteners riveted to the door are attached three grip straps for the use of the cannoneers; and to another set riveted to the top of the chest are attached three paulin straps for securing the paulin, which serves as a seat cushion. In front of the chest is provided a foot rest, a perforated sheet-metal plate the width of the chest, formed to shape and riveted on; it is supported by the middle rail and by a foot-rest brace at each side, extending from the front corners of the foot rest up and back to the sides of the chest. The rear corners are strengthened, on the right side by the brake lever shaft bearing, and on the left side by a foot-rest corner brace, which is riveted to the side of the foot rest and to the chest. The fuze-setter bracket consists of two angle irons united in the front to a bronze fuze-setter bracket separator, forming a seat, to which the fuze setter is securely bolted. In the rear the angles are hinged to brackets one outer, which is riveted to the side rail, and one inner, which is riveted to the middle rail. A fuze-setter latch, pinned to a fuze-setter latch base, which latter is riveted to the front of the foot rest, engages a pin in the bronze separator mentioned above, and thus holds the bracket with fuze setter in traveling posi- tion. For use the fuze setter with bracket is released from the latch and swung down and supported by a jointed rod extending from the separator to the fuze-setter latch base. This jointed rod consists of an upper and a lower rod pinned together, and also pinned at both ends, the flexibility of the connection allowing the rod to fold up when the bracket is swung up for traveling. The fuze-setter latch is the same as, and the parts are interchange- able with, the apron latch described above, with the exception of the handle, which, on the fuze-setter latch, is designed as a finger hold 115 to be lifted in releasing. This arrangement obviates the possibility of dropping down the fuze setter by accident. A long-handled shovel is carried under the middle rail, the end of the handle resting in the lunette bracket, while the blade rests in a bracket riveted to the sides of the middle rail under the foot rest. The shovel is secured in position and held tightly against the middle rail by a leather strap passed around the handle near the blade and attached to the tie-rod bolt sleeve. On the back of the chest are carried an ax, resting in an ax-head bracket and an ax-handle sup- port ; a pick mattock, resting in a pick-mattock head bracket and an ax-handle support, the handle being prevented from coming out of the head by a pick-mattock handle stop, riveted to the side of the chest; and a spanner and a wrench, each carried in two wrench holders. These brackets are all riveted to the chest back, and all the implements are secured by leather straps, engaging in strap fasteners riveted to the chest back, those for the wrenches, how- ever, being riveted to the intermediate bottom plates. " A name plate is attached to each caisson on the middle-rail top cover plate just in front of the foot rest, which gives the number, name of caisson, model, name of manufacturer, year of completion, and initials of inspector. In all reports and correspondence the caisson should be designated by the number, name, model, etc., given on this name plate. In requests for spare parts for repairs, etc., the parts should be asked for by the names given on the plates or in the paragraph giving nomenclature of parts in this handbook. CONVERTED 3-INCH LIMBER, MODEL, OF 1908. [Plate XXII.] WEIGHTS, DIMENSIONS, ETC. Weight, complete, empty pounds 1, 050 Weight of tools and equipment i do 135 Weight of ammunition carried do 770 Weight, completely equipped and loaded do 1,955 Weight of gun, carriage, and limber, completely equipped with 45 rounds of ammunition pounds 4, 475 Rounds of ammunition carried in limber chest 41 Diameter of wheels inches 57.75 Width of track do 60 Free height under limber (and carriage) do 22 Turning angle with carriage degrees 73 Turning angle with caisson do 75 116 NOMENCLATURE OF PARTS. No. Name of part. Location, etc. Property clas- sification. Class. Section 1 1 1 1 1 2 2 1 1 4 2 1 22 16 12 1 50 4 1 2 1 1 2 2 1 2 1 1 2 2 1 1 1 1 2 2 I I 2 1 1 1 2 1 1 3 1 1 2 2 8 1 1 1 2 1 2 2 1 1 1 1 1 Assembling bolt On rear part of frame IV 3 Ax chafing plate Screwed to chest Ax-handle support Bolted to top of chest Ax pocket do Bearing plate 2 inches wide Screwed to door do For pintle bearing Bolt' 75 inch by 5 6 inches ... do Bolt, steel, square head machine, 0.375 inch by 2 inches. Bolt snap 625 inch Secures hand rail to chest For rear door Bushing Forced in rear part of pole Carriage bolts: 0.187 (A) inch bv 1 . 25 inches 187 (-rV) inch bv 1 5 inches For chest i do 25 inch bv 3 25 inches do 25 inch by 1 5 inches Secures ax-handle support to chest For door attachments ! 312 (fa) inch by 1 5 inches 312 (&) inch bv 2 75 inches For door prop guide Cartridge case packing, intermediate: With finger notches at A In chest With finger notches at B do Cartridge case packing upper do Cartridge case packing lower . . do For doubletree Chain 2 52 feet long For chest door j Chain ring Chain rivets Riveted to chest door Chest back plate Bolted to rear part of chest Chest bodv Secured to frame Chst bracket right Riveted to side rails Chest bracket left do Chest straps Bolt chest to frame Clamp bolt and nut On sheathing clamp Copper sheathing On pole " - - Corner iron Corner post right do Corner post left do Cover do Cross rail . . Riveted to side and middle rails Crown nuts: 625 inch For chest strap bolts 0.75 inch For pintle bearing bolts Door woodwork complete On rear of chest Door hanlle On door j Door hinge center door strap Bolted to chest Door hinge center lid strap do Door hinge, end, door strap .do Door hinge en 1 ! lid strap do Part of door Door jamb, left do Door prop ... Attached to chest door and door-prop guide. Bolted to side of chest Door-prop guide right Door-nrop guide left do Doubletree Fits on doubletree bolt and strap Door-prop rivet Connect door prop to door prop stud . . Bolted to chest ' Doubletree bolt brace Fits on doubletree bolt and strap j Dowel oak 375 d For door jamb En 1 and stav hook, right On doubletree Eni and stay hook left do End bracket On footboard Eni link On doubletree chain Filler piece On chest Footboard Secured to front of frame Footboard compartment, right LTnder footboard do Footboard compartment left Footboard hinge Riveted to footboard Footboard latch and strap Front stay On footboard Bolted to front of chest Handrail Bolted to side of chest Hatchet blade bracket: Boiy Bolted to front of chest Haniie rest do Hatchet hanlle rest do ... Lantern bracket body do Lantern bracket bottom Riveted to lantern body..., 117 NOMENCLATURE OF PARTS-Contlnued. No. 2 2 2 2 2 1 1 4 2 2 1 1 1 1 1 1 1 1 1 52 24 8 54 4 10 2 6 1 4 8 8 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 1 1 1 1 1 2 2 2 4 Name of part. Location, etc. Property clas- sification. Class. Section Lantern strap fastener On lantern bracket body. 1 IV On end of axle Linchpin and clasp Linch washer Lock bar right On chest door. Lock bar left do Lock bar hinge . Bolted to bottom of chest Lock-bar plate 2 42" long On chest Lock-bar plate 2 75" long do .... Middle-rail bracket right Riveted to middle rail Middle-rail bracket left ^ do Middle rail Seated on axle Middle-rail brace rear do Secures axle to middle rail Middle-rail understrap bolt Riveted to middle rail Neck-yoke stop Secured to understrap of pole 187 (-%) inch 25 inch " do . 25 inch For tire bolt 312 (-fe) inch. For carriage bolt 375 inch For machine bolt 375 inch For tie rod 5 inch For door prop stud . 625 inch 75 inch For doubletree bolt . Packing corner iron Screwed to corner of packing Packing support, middle 2 16 wide Between chest packing Packing support middle 2 25 wide do Secured to side of chest Packing support side left do Padlock No 850 On chest door Pick mattock bracket Riveted under rear of frame Pick mattock handle support do Pickax support Riveted to side rail Pintle Fits in pintle bearing Pintle bearing Bolted to middle rail Pintle latch Pinned to pintle Pintle latch pin Joins pintle latch to pintle Pintle latch spring . . . On pintle latch . Plate Bolted to chest door . Pole body Secured to frame Pole bolt On middle rail Pole ferrule On front end of pole Pole pad do Pole pad band Attached to pole pad Riveted to side rail Pole-prop carrier, left . . . do Pole stop Riveted to middle rail Projectile packing, intermediate Inchest... . Projectile packing, upper . do Projectile packing lower do Prop chain Attached to prop . . Prop-chain button . Riveted to foot board, . Prop-chain fastening Riveted to prop tube Prop-chain handle .... Secured to prop chain. Prop eye Pinned to top of prop . Prop foot Pinned to bottom of prop Prop tube... Forms body of prop . . Rear brace, right Riveted to side and middle rails Rear brace, left .do .. ... Separator . . . On doubletree Sheathing clamp Clamped to pole Shovel blade bracket. . . Secured under frame .... Shovel handle bracket . do Side rail, right Part of frame Side rail, left.. do. Side rail and chest bolt, front Joins side rail to chest Side rail and chest bolt nut On side rail and chest bolt Side rail brace rod, forward.... Riveted to side and middle rails... Side rail filler plate, right Riveted to side rail Side rail filler plate, left do Side rail understrap, right. . . .do... do do Side rail understrap, left dn Side rail understrap bolt . . , 118 NOMENCLATURE OF PARTS-Continued. No. Name of part. Location, etc. Property clas- sification. Class. Section. 4 2 1 4 2 1 2 3 12 9 8 2 66 2 2 10 8 2 2 2 2 Side rail washer. On side rail understrap bolts ; IV 3 Split ri-s: 0. 093 (A) inch by 0.75 inch 0.156 (&) imch by 1 inch ... ... 0.156 (A) inch by 1.5 inches Staples On side rails.... Strap fasteners: No 1 No 2 No 3 No. 5..., No 10 Tie rod 18 inches long Secure packing to chest Tie rod, 42.3 inches long . . .do Washer brass For No. 6 wood screw. Washer leather For wheel Washer, steel For 0.187 (fV) inch rivets Washer steel, 375 inch For tie rods . . Washer steel 5 inch do Wheels, complete Wing nut . On wing nut pin. . Wing nut pin washer do Riveted to chest body DESCRIPTION OF THE CONVERTED 3-INCH LIMBER, MODEL OF 1908. [Plate XXII.] The limber is of metal throughout except the chest body, pole, footboards, and spokes and felloes of the wheels. The principal parts are the ammunition chest, axle, frame, pole, doubletree, singletrees, neck yoke, and wheels. The ammunition chest is a rectangular wooden box with alumin- ium and wooden packing for holding 41 rounds of ammunition and three oil cans. A steel back plate is riveted to the rear of the chest which is perforated and forms a stop for the rims of the cartridge cases. The chest door is hinged at the bottom and opens downward and to the rear. A door prop and various implement fastenings are attached to the chest. The chest is covered with heavy cotton duck. The axle is hollow and of wrought tubular steel, 3 inches in diame- ter, f-inch walls. Upon it are shrunk three square forgings with chamfered corners. One of these 6 inches long is at the middle of the axle and one 9f inches long is at each end inside the wheel spindles, the outer part forming the shoulders. The frame, which consists of a middle rail, two side rails, and braces, is seated upon the squared part of the axle and is secured thereto by understraps. The pole is of wood and has a copper sheathing, a leather pole pad on the forward end and a neck-yoke stop on its underside. The pole is also provided with a folding prop. Ill) The doubletree is made of steel and is mounted upon the double- tree bolt. This bolt is part of the doubletree bolt strap, being forged solid therewith. The singletrees are of steel and shaped similar to the doubletree. The wheels are of the Archibald pattern, 57f inches in diameter. CONVERTED 3-INCH CAISSON, MODEL OF 1908. . [Plate XXIII.] WEIGHTS, DIMENSIONS, ETC. Weight, empty, without implements and ammunition pounds 1, 300 Weight of tools and equipment carried do 90 Weight of ammunition carried do 825 Weight, complete, equipped and loaded ^ do 2, 215 Weight with limber, completely equipped and with 44 rounds of am- munition pounds 4, 170 Rounds of ammunition carried number 44 Diameter of wheels inches 57. 75 Width of track do 60 Free height under caisson do 24 Turning angle degrees 75 NOMENCLATURE OF PARTS. No. Name of part. Location, etc. Property clas- sification. Class. Section. 1 1 2 1 1 1 1 2 2 2 2 1 2 1 1 2 4 1 2 8 2 2 1 1 1 1 1 1 1 1 1 2 Ammunition chest (woodwork, complete). Apron On top of frame , rv 3 Hinged under frame Apron hinge, center. Riveted to -apron Apron hinge, side right do Apron hinge, side, left do \pron-hinge bracket, center right Riveted to middle rail Apron-hinge bracket center left do Apron-hinge bracket, side Riveted to siderail . A.pron staple Riveted on apron Arm attachment (brake) Bolted to bralce arm . . Arm attachment screw bolt Bolts arm attachment to brake arm. . . Top of chest Ax chafing plato Ax-handle support Ax-pocket body do Ax-handle rest do Axle Bearing plate, 2 inches wide... Screwed to door. . . Bearing plate, 2.5 inches wide do . . Blocking (middle rail) Over axle in middle rail Blocking (side rail) Over axle in side rail Bolt, steel, square head, machine, 0.375 inch by 2 inches. Bolt snap, 0.625 inch Connect hand rails to chest On chains riveted to door Bracket Between under strap and middle rail.. Riveted to siderail right Bracket hinge Bracket-hinge bolt, right Bolts arm of fuze-setter bracket to bracket. Bolts arm of fuze-setter bracket to middle rail. Hinged on brake-arm hinge bolt do Bracket-hinge bolt, left Brake arm, right ... Brake arm left Brake-arm hinge boit Hinges brake arms to middle rail Riveted to left brake arm ... Brake-arm hi^ge pie "6 Brake lever, right Riveted on brake segment bracket. left. Riveted on brake-segment bracket, right. Holds brake levers on segment brack- ets. Brake lever, left Brake lever bolt and nut 120 NOMENCLATURE OF PARTS Continued. No. 1 1 1 1 2 2 2 13 12 6 35 7 6 12 36 6 4 1 2 1 1 2 4 2 1 2 4 1 1 1 1 1 1 2 1 2 1 1 1 2 2 1 1 1 1 2 1 1 2 2 6 8 1 3 1 1 1 2 2 1 2 4 1 1 1 2 Name of part. Location, etc. Property clas- sification. Class. Section. Brake segment right Riveted to brake-segment bracket, right. Riveted to brake-segment bracket, left. Clamped to axle IV 3 I Brake segment left Brake-segment bracket left .do Brake-segment bracket bolt Clamps segments to axle Brake shoe Bolted to Drake arm Brake-shoe screw bolts Bolt shoes to brake arms . Bolts (carriage): 187 (A) inch by 1 25 inches 187 (A) inch by 1 5 inches 187 (A^ inch by 2 25 inches 25 inch by 1 25 inches . 25 inch by 1 5 inches . 25 inch by 2 25 inches 25 inch by 2 5 inches 25 inch by 3 25 inches 312 (A) inch by 1 5 inches 312 (A, ) inch by 1 75 inches 312 (A) inch by 2 75 inches Cartridge case packing In chest, intermediate with finger notches at A. In chest, intermediate with finger notches at B. Do . Cartridge-case packing lower do Chain 2 52 feet long [Connected together and riveted to f chest. Screwed onto packing Chain ring Chain rivet Chest back plate Chest strap Screwed to side of chest, bolted to side rail. Screwed to corners of packing Corner iron Inside chest rear right side Corner post left Inside chest, rear, left side On top of chest Cover leather (for pole strap) Cross rail front Bolted to side rails and mi idle rail Bolted to rear ends side rails Cross rail , rear Crown nut 625 inch On side rail and chest bolt, front . . Door (woodwork complete) Rear of chest Door end plate Bolted to outer face of door Door handle do Door hinge, center, door strap do Door hinge center lid strap Bolted to underside of lid top Door hinge end door strap Bolted to outer face of door. Door hinge end lid strap Bolted to underside of lid top Door joint right Rear end of right side of chest Door joint, left Rear end of left side of chest Door plate right Bolted to outer face of door Door plate, left do D oor pr op A 1 7 .562 ( 1 7 A-inch) On door prop studs Door prop guide, right Riveted to outside of chest, right side.. Riveted to outside of chest, left side. . . Runs in door prop guide attached to end of door prop. Riveted to end of door Door prop guiie, left Door prop sliding rivet Door prop stud, H=.4 inch Trowel fl 375 ifioh In door joints Filler piece At ends of packings Footboard Secured to footboard brackets . Footboard bracket Secured to middle and side rails Riveted to front of middle rail, right side. Riveted to front of middle rail, left side. Inner face of front of chest Frame handle, right Frame handle, left Front shield Front shield cleat, bottom Bolted tobottom of chest,bears against front shield, do Front shield cleat side Front stay Bolted to front of chest Fuze setter bracket (2 pieces) Attached to side rail and middle rail, under right side of chest. Bolted to r>ort_ . Lunette Riveted to end of middle rail i Lunette prop attachment front Fastened to rear end of chest body Hn Lunette prop attachment rear Middle rail . Fastened to axle Middle rail bolt ! Middle rail reinforce right TMirptpH tn miHrnfi rail Middle rail reinforce left do Middle rail separator Fit on middle rail bolt Name plate Nuts, steel, special: 5-inch For end tie rod 5-inch For spring assembling bolt 656-inch (fi) For rear bolster bolt . .... 5-inch hexagonal, 0.875-inch flats Nuts, steel, standard: 187 inch (A) TTnr parriapp. hnlt. 375-inch 1 For spare wheel fastening bolt 375-inch For center and front bolts 5-inch For brake segment bolt 0.625-inch.. 137 NOMENCLATURE OF PARTS Continued. No. Name of part. Location, etc. Property clas- sification. Class. Section. 2 4 4 4 4 4 4 2 3 1 2 1 1 1 "1 1 1 120 1 1 1 1 1 1 8 4 4 4 4 4 4 8 4 2 8 2 4 4 2 8 2 4 2 4 2 1 1 2 1 120 2 2 2 6 4 2 2 1 4 2 4 4 4 18 Beneath frame, left and right sides front. IV 9 Consisting of: Oil can carrier slat Oil can lid packing . . . Padlock Chained to chest body do Pin Driven in spare wheel lock pin Rear bolster bolt Rear cross bar Riveted to side and middle rail Rear end attachment Fastened to bottom rear center of chest body. Riveted to middle rail and rear cross bar. .do Rear middle rail bracket, right Rear middle rail bracket, left Rear side rail bracket, right Riveted to side rail, right and rear cross bar. Riveted to side rail, left and rear cross bar. Rear side rail bracket left . Screws, brass, round-head, 0.75-inch, No. 6. Side rail right Seated on axle Side rail left do Side rail reinforce, right Riveted to side rail, right Side rail reinforce left Riveted to side rail, left Sleeve Fits on rear bolster, bolt Spare wheel chafe plate right Screwed and riveted to chest body, right side. Screwed and riveted to chest body, left side. On chest body sides Spare wheel chafe plate, left Spare wheel fastening bolt Spare wheel fastening bracket Bolted on chest body sides Spare wheel fastening chain Fastened to chest body sides . Spare wheel fastening hinge, male Assembled with spare wheel fastening bracket, do Spare wheel fastening hinge female Spare wheel fastening hinge'pin do Spare wheel fastening link '. Assembled with spare wheel fastening bracket. Spare wheel fastening pin Spare wheel fastening reinforce Bolted on inside of body . . Spare wheel support . Bolted on chest body Spare wheel support bolt, nut, and washer. Spare wheel support cap On chest body top Assembled with spare wheel support . . Split pins: 0.093 inch (^) by 0.5 inch 093 inch (^) by 625 inch 0.187 inch ta) by 1.125 inches 125 inch by 1 25 inches 312 inch (-fs) by 1 5 inches 0.375 inch by 4 inches Spring Bolted to brake link and brake arm attachment. In brake link and brake arm attach- ment. Bolted to cover board Spring assembling bolt Strap fastener. Turnbuckle stud Riveted on rear board of chest Understrap Bolted to middle rail Understrap bolt Upper tie rod and nut Through chest body Washer, brass. For No. 6 wood screw Washer, leather For wheel Washer, steel For brake segment stud Washer, steel . For rear bolster bolt Washer, steel For 0.187 inch ( T \) carriage bolt Washer special Washer, steel. For 0.312 inch (& inch) D stud Washer, steel Washer steel For turnbuckle stud Washer, steel, special For end tie rod , Wheels, complete Wing nuts On wing nut pin Wing nut pin... Riveted in oil can carrier bracket Wire staples 138 DESCRIPTION OF THE CONVERTED 3-INCH BATTERY WAGON, MODEL OF 1908. [Plate XXV.] The principal parts of the battery wagon are the body, axle, road brakes, and wheels. The body, which is made of wood and bolted to the frame as shown on plate XXV, is provided with interior compartments. Three doors are provided for the body, two on top, at the front and rear ends, and one in front of body. Strengthening braces of wood and steel are provided. Spare wheel supports and spare wheel fastenings are se- cured to the top and side of the body for transportation of spare wheels. Suitable hinges, hasps, padlocks, etc., are provided for the body. In the compartments are carried the grindstone and can of oil, secured by a permanent packing; and tools, spare parts, and small stores. The axle, frame, and road brakes are similar in construction to those of the caisson. The wheels are the same as used on the con- verted limber and caisson. 3-INCH GUN AND 3.8-INCH HOWITZER, STORE LIMBER, MODEL OF 1902. WEIGHTS, DIMENSIONS, ETC. Weight of store limber, empty pounds 955 Weight of store limber, completely equipped and loaded do 1, 106 Weight of store limber and store wagon, both completely equipped and loaded pounds 4,008 Diameter of wheels inches 56 Width of track __do__ 60 Free height under limber __do__ 26. 5 Turning angle with store wagon degrees 75 The store limber, model of 1902, is substantially the same as the forge limber, model of 1902 except that the chest is fitted with com- partments for carrying the following battery fire-control equipment : 10 battery commanders' rulers, wooden. 1 1 battery commander's telescope and mount in case. 1 battery commander's telescope tripod in case. * 5 flash lights with hoods. 16 flash lights without hoods. 1 steel tape, 100 feet. 2 time interval recorders, with chains. Fire-control equipment furnished by the Signal Corps. The compartments for telephones, field glasses, battery command- er's telescope, and battery case are padded to protect the contents from injury. STORE LIMBER, MODEL OF 1902 Mi. The store limber, model of 1902 Mi, is the same as the store limber, model of 1902, except that it has the identical automatic pole sup- port used on the caisson limber, model of 1916. 1 Metal B. C. rulers with cases may be retained until supply is exhausted. 10261417 12 139 THE STORE WAGON, MODEL OF 1902. WEIGHTS, DIMENSIONS, ETC. Weight of store wagon, empty pounds 1, 19O Weight of store wagon, completely equipped and loaded do 2, 902 Diameter of wheels __inches__ 56 Width of track __do__ 60 Free height under store wagon do 26 Turning angle i __degrees__ 75 The store wagon, model of 1902, is the same as the battery wagon r model of 1902, with these exceptions: The vise is omitted, and a frame handle is attached in its place; the store-wagon body forms a single compartment, with two doors on top, the tool-box compartments of the battery-wagon body and the door opening into them being omitted. A crowbar support, front, takes the two left inside rivets for the cross brace, and a crowbar support, rear, is riveted to the chest bottom in front of the axle. A strap fastener with a strap on the left side rail secures the crowbar in the supports. Arrangements similar to those of the battery wagon are made for carrying two- spare wheels and three oil cans. The store wagon is intended pri- marily for carrying such stores, spare parts, and materials as can not be carried in the battery wagon, and, in addition, such stores as may be designated by proper authority. The battery and store wagons, model of 1902, which are now in service are being modified as they are turned in to an arsenal for repair or alteration. The main modifications are the addition of a foot rest at the front of the chest, transferring the brake system from the rear to the front of the vehicle, and adding handrails, grip and paulin straps to the chest. Axle blocks are added to support the chest under the spare wheels. 3-INCH GUN BATTERY AND STORE WAGONS, MODELS OF 1902 Mi. WEIGHTS, DIMENSIONS, ETC. Weight of battery wagon, empty pounds 1,444 Weight of battery wagon, completely equipped and loaded do 2, 947 Weight of forge limber and battery wagon, both completely equipped and loaded pounds 4, 524 Weight of store wagon, empty do 1, 390 Weight of store wagon, completely equipped and loaded do 3, 102 Weight of store limber and store wagon, both completely equipped and loaded pounds 4,208 Diameter of wheel inches 56 Width of track do 60 Free height under wagons do 24. 5 Turning angle with limbers degrees 75 Weight (approximate) at lunette of both wagons, loaded -pounds 112 140 NOMENCLATURE OF PARTS. fl . o a H ) 0> 53 S2 .... 2 1 1 2 * 8 2 1 2 1 1 1 1 1 1 1 2 4 -6 2 1 1 :2 1 1 2 2 2 4 2 2 1 1 "ie" 16 4 "i" "2" 2 "2" 2 1 "*4 Number on battery wagon. Name of part. Location, etc. Property clas- sification. Class. Sec- tion. 1 1 2 1 1 2 2 8 8 2 1 2 1 1 1 1 1 1 1 2 4 6 2 1 1 1 2 1 1 2 2 2 2 2 2 1 1 16 16 2 2 2 4 1 1 1 1 1 1 1 1 2 1 "Y 3 1 1 1 2 In grindstone packing "A" 1 IV J <) Axle Bearing plate (transverse brake) At upper ends of transverse braces Riveted to brake channel . . . Brake-beam guide, right Brake-beam guide left . . do Brake-beam pin Brake beam Hinged in brake box Brake bolt In brake-lever pivot backing Brake-bolt nuts On bolts Brake-box filler Riveted to end of brake channel Brake channel Fastened to side rail Brake crank . On brake shaft Brake guard . . Attached to segment Brake lever On brake-lever pivot Brake-lever catch On brake lever ... Brake-lever pivot Riveted on wagon body do Brake-lever lower filler Between pivot and box body Brake-pivot side filler do Brake rod . .... Connects brake beam and brace crank. On end of brake rods and connecting rod. Brake-rod end Brake-rod pin Brake-rod spring Inside of brake-spring cover Brake segment . ... Upper end bolted to box; bodv Brake-segment brace Supports lower end of brake segment . . In bearings on axle Brake shaft Brake-shaft bearing On brake shaft Brake-shaft bearing, right do Brake-shaft crank On right end of brake shaft .... Brake-shaft bushing In brake-shaft bearing Brake-shaft bushing, right . . . . In brake-shaft bearing, right Brake shoe On outer end of brake beam Brake-shoe tap bolts Fasten brake shoe to beam Brake-spring cover Connects brake-spring cover head and end. Screwed into brake-spring cover Brake-spring cover end Brake-spring cover head On brake rod and screwed into brake- spring cover. Riveted to end of brake channel Box bottom left do Box front Front of battery- wagon body Cap screw flat head Attach spare-wheel fastenings Screw cap, hex head do Chain (door) In chain fastenings Chain fastenings (body), 1 right, 1 left. Chain fastenings (door) Bolted to corner irons, rear Riveted to door Channel support Fastened to side rails Cleat, inner ^ On cover board, locates chest for spare breech mechanism. do Cleat, outer Brake rod Connects brake shaft crank and brake lever. On box body do Corner iron, inner (rear), right Corner iron inner (rear) left Corner iron^ inner (front), right .do. ... Corner iron' inner (front)' left do Corner iron, outer (rear), right Bolted through box body to corner irons, inner, do Corner iron outer (rear) left Corner iron, outer (front), ri^ht . . .do Corner iron outer (front) left do Cover Over ton of box bodv. . . Cover board 1 Over nartitions Cross brace Riveted to side rails Cross rail, front Under front of floor body Cross rail, intermediate Under middle of floor body Cross rail, rear '. Under rear of floor body Crowbar support, front Riveted to left side rail Crowbar support rear Riveted to floor (underneath) Door boards In door bodv Door hinge plate Attached to floor of battery wagon Riveted to door of battery wagon do . Door hinge, strap, center , . . . Door hinge strap outer left do End strap On box front of batterv wagon and front and tail boards of store wagon. 141 NOMENCLATURE OF PARTS-Continue 1. Number on I store wagon. | Number on I battery wagon. 1 Name of part. Location, etc. Property clas- sification. Class. Sec- tion. 1 6 1 1 1 1 2 1 1 1 1 | 1 . "~4 2 "2" 2 2 2 2 1 1 "e" 8 2 2 "io" "e" 6 4 4 2 2 4 1 2 2 2 2 1 1 1 6 1 3 1 1 2 1 1 1 j 1 I i i 4 1 1 1 1 1 1 4 2 1 2 3 2 3 3 1 1 1 1 1 3 6 8 2 2 1 2 10 4 6 6 4 4 2 2 4 2 3 3 2 1 1 In floor body IV Floor board intermediate do Floor board, left ..do Floor cleat right Screwed to floor Floor cleat, left .. do... Floor cleat, front, right . . do . Floor cleat Iront left do Floor cleat, rear, right do . , Floor cleat rear left . . do Floor plate 1 in cover board at chest lor spare breech mechanism; 2 in side boards at packing chest for supplies. Between brake guard and side board. . R iveted to right side rail at lock bar. . . On brackets . - Filler block... Filler plate Foot rest Bolted to front of body Foot-rest bracket, outer, right do Foot-rest bracket, outer, left do Foot-rest support, right Tie outer corner of foot rest to end stiffener. do Frame handle right On front end of side rail Frame handle, left do Frame reinforced plate . . /do Front board Front of ''tore-wagon bodv Front brake brace, right Braces channel to side rail Front brake brace, left do Grindstone-frame pedestal Grindstone-leg bracket, right end Grindstone-leg bracket, left end Riveted to tailboard do Grindstone lower packing ... Screwed to cover board Grindstone packing "A." Bolted to forward lid Grindstone packing " B ". . do Grindstone packing "C" do Grindstone packing nut G rindstone packing stud In lower packing Handrail bracket On lid Handrail tube On brackets Hasp plate (door) Riveted to door . . Hasp plate (lid) Riveted to lid Hasp Assembled to hasp plates Hasp rari In lid body Hasp staple R iveted to staple plate i Hasp-staple plate Riveted to from and tail boards. Hinge board, front Top of box Hinge board, rear .do Hinge board brace, front, right Riveted on underside of hinge board, front, do Hinge board brace, front, left Hinge board brace, rear, right Riveted on underside of hinge board, rear. do ' Hinge board brace rear left Hinge rivet (door) in hinge Hinge rivet (lid) Joins plate and strap Hinge rivet (spare wheel fastening bar) Hinge rivet (spare wheel support swing bolts). Hinge rivet (spare wheel support stud) Jackscrew-base packing. . . In hinge ...do do On cover board Jackscrew-handte packing do Lid boards *. In lid bodv Lid brace.. F iveted on underside of lids Lid hinge plate On top rail Lid hinge strap On lid . Li d prop Hinged to lid Lid prop pin Screwed into lid hinge straps Lid prop plate, right . . Screwed to sideboard Lid prop plate left do Lid prop rivet In lid prop Lock chain . . For locking oil can bar on catch Lock-chain ring Or lock chain Lock-chain staple Riveted to staple plate ... Lock-chain staple plate Screwed to front and tailboards and door of battery wagon. On tie-rod vertical Lock washer Lunette In lunette bracket Lunette bracket . . . Front end of side rail. .. 142 NOMENCLATURE OF PARTS Continued. Number on store wagon. Number on battery wagon. I Name of part. Location, etc. Property clas- sification. Class. Sec- tion. 2 1 1 1 1 16 1 1 1 1 1 3 3 2 1 1 6 1 1 1 3 "Y 1 4 2 1 1 1 1 1 2 2 8 6 1 1 1 1 1 2 .... 1 2 1 1 1 1 16 1 1 1 1 1 3 3 2 3 1 1 1 1 2 I 2 1 1 1 1 1 2 2 8 6 3 7 2 10 4 4 Lunette-bracket filler plate Riveted to bracket IV 9 Lunette nut On lunette Middle brace, right Riveted to axle and rail. . . Middle brace left dn Name plate Riveted on left side rail . Oil-can bar Hinged to left side rail Oil-can bar catch Riveted to right side rail Oil-can bar bracket On oil-can bar Oil-can bar buffer do Oil-can bar staple ... In bracket Oil-can locking plate On oil-can bar Oil-can slats (rectangular) On oil-can supports Oil-can sla* s (T shaped) do Oil-can slat, right ( L shaped) do Oil-can slat left ( L shaped) do ... Tie supports to wagon body Oil-can support front Riveted to side rails rear of axle do Oil-can support rear do Padlock with 1 bolt snap, 1 chain, and 1 chain ring. Padlock with 2 chain rings and t l chain. Partition front On chest for lids and for lock bar On chest for door Transversely in box Partition right Longitudinally in box Partition, left do Prop chain All parts of the prop are pinned or riveted together. Fasten to side rails Prop-chain button Prop-chain ring Prop-chain guide Prop foot Prop eye right Prop eye, left Prop fastening pin Prop hook- Prop tube Prop chain clamp Rail bolts Rail-bolt brackets Riveted to side rails Rear board Rear of box Rear-brake brace , right Braces channel to side rail Rear-brake brace left do Reinforce (brake segment brace) Inside front board (box front) . Segment rack Riveted to brake segment Separator Between brake segment and brake guard. At corner of door . ... Shot bolt left Shot bolt right do Shot-bolt bracket left Screwed to rear door Shot-bolt bracket, right . . do Shot-bolt eve On corner iron rear Shot-bolt stop Screwed to rear door Side brae front left On sideboard Side brace front, right . .. do Side brace rear left ' do Side brace, rear, right do Side-brace rear clip, left > do Side-brace rear clip right do Side board left Side of box Side board right . do Side rail left "Ri-o-Atp.rtt.na-vip.1nps- . . Side rail right do Side strap Inside of sideboards Slip tongues (door) Tn door boards . . Slip tongues (floor) In floor boards Slip tongues (lid) In lid boards Slip tongues (sideboard) Tn eirip>->rmrH<5 Spare-wheel fastening bar On side braces front and rear Spare-wheel fastening base Spare- wheel fastening clip Spare- wheel fastening swing bolt Spare-wheel fastening stud Riveted to brake channel Spare- wheel fastening nut Spare-pole rest Spare-pole fastening bolt. . . Fits through spare-pole support, front. 143 NOMENCLATURE OF PARTS Continued. Number on 1 store wagon. ! Number on 1 battery wagon, j Name of part. Property clas- sification. Class. Seo- tion. 1 1 1 2 2 2 2 2 2 2 1 2 "4" 2 .... 1 1 2 1 1 1 1 1 1 1 6 2 1 2 2 2 "2" 1 1 1 2 2 2 2 2 2 2 "2" 2 4 2 2 1 1 1 1 2 1 1 1 1 1 1 1 6 2 1 f 1 ! Riveted to lunette bracket IV 9 Spare-pole support rear Riveted to pad on axle Spare-pole support cap Bolted to spare-pole support, rear In spare-pole support, rear ............ Spare-pole support bolt On top rail of box ................. Spare-wheel support cap Spare-wheel support clip Spare-wheel support stud Spare-wheel support swing bolt On left-side rail ... Spare- wheel support nut Strap fastener crowbar On box body Strap fastener jackscrew On cover board Strap fastener paulin On box body Stiff ener Riveted to front and tail boards Supply-chest supports (right and left) . Tailboard Screwed on sideboards Rear of box Tie-rod end (front) ... At upper edge of front board Tie-rod end (rear) At upper edge of tailboard Tie-rod, center Horizontal rod through center of box. . Under top-rail Tie-rod, upper Tie-rod vertical Vertical rod through middle of box Top of box Top rail Transverse brace, left Inside, from middle of floor to spare- wheel supports. do Transverse brace, right Vertical tie-rod washer At transverse braces Washer (brake) Under head of upper brake segment bolt. On brake-lever pivot Washer (brake lever) Washer (oil-can bolt) Under heads of oil-can bolts Wheels On axle Wheel rest On wheel-rest supports 1 Wheel-rest support . . . . . On axle .. .. Wheel-support strap, front, left 1 From spare-wheel supports to wheel- 1 support tie-plates. Wheel-support strap, front, right Wheel-support strap, rear, left Wheel-support strap, rear, right Wheel-support tie plate . . Under axle In replacements of wooden parts of these wagons it will be neces- sary to change locations of hasps slightly in certain cases, as well as make necessary fittings., due to the fact that wooden parts warp and shrink in service and in store, and can not be made completely interchangeable. 3-INCH GUN AND 3.8-INCH HOWITZER BATTERY WAGON, MODEL, OF 1902 Ml. DESCRIPTION OF PARTS WHICH DIFFER FROM THE BATTERY WAGON, MODEL OF 1902. The chest, with attachments, is much stronger, braced better, and is secured more satisfactorily to the frame. The weight of the spare wheels is carried directly by the axle instead of at the top of the chest. The parts of the chest are belted and screwed together, so that they may be readily disassembled if necessary. The floor is made of matched poplar boards instead of paneling, and is raised and supported above the frame by means of a channel steel-wheel rest above the axle and two parallel oak cross rails in front and two cross rails in the rear. Angles are riveted to the frame to take the eight rail bolts which secure the chest to the frame. 144 The ends of the wheel rest project beyond the sides of the body and lie on bronze wheel-rest supports above the axle. Wheel-sup- port straps, front and rear, extend from the spare-wheel supports, and they are bolted to the inside of the body and pass below the axle, to which they are clamped by the wheel-support tie-plates. Two additional tie-rods are across the center of the chest at the top. The corners of the chest are not dovetailed but reinforced by corner irons, inner and outer. Side straps are bolted through the intermediate cross rails. The door and lids are made of matched poplar boards except the hasp rail of the lids, which is of oak. In the forward part of the wagon on the floor are cleats which locate the chest for spare sights and the packing chest for spare parts. By means of supply-chest supports, which serve as guides on the inside of the sideboards of the wagon, the packing chest for supplies may be drawn to the front as an open drawer when it clears the lid of the wagon and then slid back under the top of the wagon in the closed position. It is held in the latter place by means of barrel bolts locking in two floor plates. A list of contents is on the inside of the supply chest at the rear. 3-INCH GUN AND 3.8-INCH HOWITZER STORE WAGON, MODEL OF 1902 Mi. The store wagon, model of 1902 Mi, is the same as the battery wagon, model of 1902 Mi, with the exceptions noted under the dif- ferences between the store and battery wagons, model of 1902. CYCLOMETER. The store limber of each 3-inch gun battery is fitted with a de- vice which registers the number of miles traveled. This instru- ment, called a cyclometer, is mounted on the left tie-rod clamp at the rear of the axle and is composed of a star wheel and shaft actuating a train of gears which bring figures representing 0.1 mile to 9,999.9 miles before a glass window in the usual manner of such meters. A tally pin riveted to the wheel hub strikes the star wheel and moves it one tooth at each revolution of the wheel. A special tie-rod clamp is issued with the cyclometer for all batteries. NOMENCLATURE OF CYCLOMETER PARTS. 1 bracket (on special tie-rod clamp). 1 cover. 1 stop. 1 spring. 1 tally shaft. 1 washer (felt). 1 counter. 1 case (for counter). 4 case screws. 3 bracket screws. 4 cover bolts with nuts and split pins. 1 tally pin. 145 PADLOCKS AND BOLT SNAPS. The padlocks furnished for each separate vehicle, as carriage, forge limber, battery wagon, store limber, or store wagon, excepting the limbers and caissons, will have keys interchangeable for all locks of that particular vehicle but differing from all others. Limbers and caissons are furnished with a lock, marked " AMMU- NITION," which has only one key, these being universally inter- changeable. Bolt snaps for temporarily securing doors, etc.^ are placed where no shot bolts are provided. . THE ARTILLERY HARNESS. I Plate XXVI.] The component parts of the artillery harness are given in the table below. Plate XVIII shows the harness for the off wheel and off lead horses. The nomenclature corresponding to the numbers on the plate will be found in the table. No. on Plate XVIII. Component parts. Wheel. Lead. Near horse. Off horse. Near horse. Off horse. 1-4 1 2 3 4 8,9 8 9 2-7 5 6 2 3 7 10-19 10 11 12 16 19 13 14 16 17 Backstrap and crupper complete 1 1 1 1 4 1 1 1 1 1 4 1 Consisting of Body and hip straps Crupper dock Ivoin strap Trace loops Backstrap hook Belly band complete 1 1 2 2 1 1 2 1 1 1 1 1 2 1 2 2 1 1 2 2 1 1 2 2 1 1 2 1 1 1 1 1 2 1 2 2 1 1 2 2 1 1 1 1 1 1 Consisting of Belly band .... Holding down strap Holding down strap hook Breast strap, complete Consisting of Breast strap . Breast-strap hooks Breeching, complete Consisting of Backstrap (1) and hip straps (4) Body . . .... Crupper dock Backstrap hook- Side strap hooks Loin s,trap Side straps Trace loops Bridle, complete (old model) 1 2 2 1 1 2 2 Consisting of Brow band Brow-band ornaments Check pieces Coupling strap Connecting strap Crownpiece 1 1 1 1 1 1 1 Snaffle bit 1 .. Reins (pairs) Throatlatch . . . Property classification. Class. Sec- tion. IV 8 Twenty curb bits with chains are issued for use in place of snaffle bits on fractious draft horses. 146 No. on Plate XVIII. Component parts. Wheel. Lead. Near ' Off horse, horse. Near Off horse, horse. 10 11 13 18 14 16 45 20 21 40 22,23 23 21,25 24 25 26-33 27 15 28 29 42 43 44 30 31 32 33 34 35 36 i 37 38 39 41 Bridle, complete (new model), consisting of Brow band . . 1 2 1 I 2 1 1 1 1 -t 1 1 2 2 1 { 1 Brow-band ornaments Crown piece Coupling strap Snaffle bit * 1 1 1 I Reins . Crown piece strap Collar , steel Hame tug (a part of the collar) .... Collar strap 1 1 1 2 1 1 1 1 j 2 1 1 1 1 1 1 1 1 2 i i i 2 1 1 1 1 1 1 1 1 1 1 2 2 j 1 .1 1 1 1 1 1 1 1 1 1 2 2 1 1 Halter, comp'ete ' Consisting of Crown strap Cheek piece Crown chape Nose band - Chin strap Throat band Throat strap Halter square Tie rope Martingale comp'ete Consisting of Martingale Cincha strap Saddle, complete 1 1 Consisting of Cinchas, with reinforces and loops Cinchas without reinforces and loops. 1 1 1 i Lead-rein roller and strap 1 1 1 2 2 1 2 1 2 2 1 2 Quarter straps , including rings, safes, and cincha straps (side) 2 1 1 2 3 1 2 2| 1 1 1 1 2 2 3 2 1 1 2 Quarter strap, cantle Quarter strap pommel Cincha strap, a part of the saddle quarter strap Coat strap 33-inch (pommel) Coat strap, 45-inch (oantle) Coat strap 60-inch Saddletree, leather-covered 1 2 2 1 1 2 2 2 2 1 2 2 i 2 Stirrups (nickel steel) Stirrup straps Saddlebags, pairs ... . ... Saddlebag side straps Traces lead model of 1908 Consisting of 1 trace body 1 trace cover . 3 links 1 chain . 1 toggle 2 sockets 2 cones 2 filler pieces Traces, wheel, model of 1908 2 2 Consisting of 1 trace body 1 trace cover 1 ring 2 sockets 2 links 2 chains ... 2 toggles 2 cones 2 filler pieces Mogul spring assembled 1 loop hook 1 ring 1 1 locking strap Trace chain, body 2 2 1 Whip 1 Sweat leathers 2 1 ..... 2 ! 1 1 Blanket 2 Property classification. IV 1 Twenty curb bits with chains are issued for use in place of snaffb bits on fractious draft horses. 2 In submitting; and in filling requisitions, unless it is specifically stated that saddle blankets are wanted, they will not be included. 147 STEEL COLLARS. SIZES AND DIRECTION FOB FITTING. Steel collars are made in the following sizes: 2 A, 2 B, 4 A, 4 B, 5, 5 A, 5 B, 6, 6 A, 6 B, 7, 7 A, 7 B, and 8 A. The number and shape of the collar are stamped on the front side under the extension bolt. The A and B shapes have straighter sides than the numbers without letters. When issued with harness, unless otherwise ordered, 20 per cent of the collars are No. 4 A, 30 per cent No. 5, and 40 per cent No. 5 A, and 10 per cent No. 6. In requisitions, the size of collars desired should be given. The steel collar pads are made in seven different sizes: No. is 4 inches wide, No. 1 is 4.5 inches, No. 2 is 5 inches, etc., to No. 6, which is 7 inches wide. The pad connections are also furnished in seven sizes, from No. to No. 6. For the plain number of collar (5, 6, or 7) the regular adjustment requires a pad connection of the same number as the pad. The A and B shapes have straighter sides and take a pad connection two sizes larger than the pad that is, it would take a No. 3 connection with a No. 1 pad, etc., for the regular adjustment in these shapes. When the collar is very wide at the top and narrow at the bottom the size of the pad connection must be increased one or two numbers to allow the collar to close easily at the bottom. In the reverse case, a smaller pad connection should be used. The collar pads are numbered on the front inner side. The pad connections are numbered on the side having the round holes, which side must be kept to the front on the collar. In requisitions for collar pads and pad connections the sizes desired must ~be stated. The buckle is made in two sizes. No. 2 is 1 inch longer than No. 1, and is used with the larger sizes of collar pad. The correct adjustment and fitting of collars is of the utmost im- portance. The variety of sizes and shapes of collars, pads, pad con- nections, and buckles issued by the Ordnance Department is sufficient to enable any horse to be correctly fitted. Efficient supervision by officers of the fitting of collars and of the adjustment of the point of draft (trace plate) is required to secure proper results. 148 Table of dimensions. SIZE OF COLLARS FITTED WITH NO. 3 PADS. Number of collar. Length of collar inside. Width 6 inches down from top. Width inches down from tof J . Width at draft. Number of collar. Length of collar inside. Width 6 inches down from top. Width 8 inches down from top. Width at draft. 2A... Inches. 18 Inches. 6i Inches. 1\ Inches. m 6. Inches. 22$ Inches. 7| Inches. Inches. 2B... 18 3 8 6 A 7 71 qf 4 A... 19* 7 7' 6 B... . 22j 7 74 g| 4B... igf 61 7j 7 . 24 71 n? 10^ 5.. 21 7f I 7 A 24 7 72 qi 5 A... 21 1\ 9 7B 24 7 7 10 5B 21 6 1\ gl 8 A 25i 7 JF of SIZE OF COLLARS FITTED WITH NO. 1 PADS. 2A... Mi 5 5j 7 6-.. 21 6i 7 J S-l 2B 16 4 & | 6 A 21 6 Bj 8J 4 A... 18 5 | 7 6 B 21 ft 8' 4 B 18 5 gj 7 7 fit 7| g 5 g 7j g 7 A 991 . 6J 8 5 A 19! 5^ i 7 7 B 2^1 ~| 6i 8 5B 19i 5j 5: 7 8 A 24 5^ 8j fi The tajble of dimensions gives the largest and smallest size that each collar can be made with the No. 3 and No. 1 pads. Adding one-half inch in length and width to the smallest dimensions given in the table will give the size of the collars when fitted with the No. 2 pads. These examples are given to show the three regular adjustments in each size of collar, but these dimensions can be varied to suit the different shapes of necks. The largest pad can be put in the top of the collar and the bottom taken in to its smallest dimen- sions, or the smallest pad can be put in the top and the bottom left out. While each collar can be lengthened or shortened and taken in or let out at the bottom by means of the adjustments provided, the width at the top can not be changed without using a larger or smaller pad. In fitting irregular shapes none of the connections may give just the proper tension on the pad. In such a case use the one that comes nearest and straighten or bend the extension at the top. When the collar is required to be widened at top to relieve the pressure on the pad and make it lock easily at the bottom, open the collar wide and place a round piece of hard wood or iron, 1 inch in diameter and 2 inches long, between the connection and collar side close up to the hinge; then press the sides together and bend both sides alike, so that they will be the same length at the bottom. Do not let the fulcrum rest on the pad, for it will bend it. If the collar sides require straightening to close them tighter on the pad and give more tension on the latch at the bottom, open the collar at the bottom, hook the wrench over the top of collar side, and press down the lever, treating both sides alike. I *1 c PLATE XXVIII. Collar Lifting Device. ZI6I02 I 149 Both of these operations can be performed with the collar put to- gether. Parts furnished for the repair of the collars with the correct names of the parts are shown on Plate XXVII. Canvas collar pads are not part of the artillery harness, but are furnished upon requisition. They are made in sizes Nos. 2, 3, 4 5 5, and 6, as called for; if no size is called for, they are made in equal proportions of Nos. 4, 5, and 6. COLLAR-LIFTING DEVICE. [Plate XXVIII.] This is a simple device for lifting the steel collar from the horse's neck, when, for any reason, the neck becomes sore. The straps securing it to the hame tugs afford easy attachments to or removal from the collar. By supporting the collar by canvas pads in front and in rear of the collar, the pressure is removed from the surface of the neck directly beneath the collar^ and the weight is more evenly, distributed along the neck. In case of necessity, such a device, made by the organization mechanic, will allow w y orking a horse when suffering with a sore neck. BREAST COLLAR HARNESS. The component parts of the Breast Collar Harness are given in the table below. Plate XXIX shows the harness for the off wheel horse and the off lead swing horse. The nomenclature as given in the table is also given and the particular parts designated on the plate. The essential difference between the two harness sets as shown on Plates XXVI and XXIX is in the harness used upon the neck, shoulders, and breast. Instead of a steel collar clasped about the neck and held in place by a collar strap and hame tugs, a leather strap stretching across the breast and supported by a strap run- ning over the neck is used with the Breast Collar Harness. At either end the breast collar is toggled to the trace; in front it is held down by a chokestrap which passes between the forelegs and is buckled around the cincha. On the wheel horse, the neck strap and neck-yoke neck strap are held in a collar pad which is hooked to the pommel by the pad strap and pad-strap hook. The neck-yoke neck strap encircles the neck and is fastened to the yoke pole. 10261417 13 150 COMPONENT PARTS. Wheel. Lead. Property classification. Near horse. Off horse. Near horse. Off horse. Class. Sec- tion. 1 1 2 1 1 4 1 1 1 1 1 1 2 1 , IV 8 Consists of: Body Crupper dock Loin strap Trace loops .. Backstrap hook Breast collar, complete, consists of: Breast collar -. . . 1 1 1 1 1 Chokestrap Neck strap Collar pad assembled Body Buckle chapes Pad strap with hook Neck-yoke neck strap 1 1 1 4 1 1 2 2 2 1 1 2 1 1 1 4 1 2 2 2 1 1 2 1 1 1 Breeching, complete, consists of: Body Backstrap Hip straps Backstrap hook Crupper dock ... Si je straps Side-strap hooks Trace loops Loin strap Bridle, complete (model of 1913), consists of: Brow band 1 2 1 1 1 2 1 1 1 1 1 1 2 1 1 1 1 1 2 1 Brow-band ornaments Crownpiece. Crownpiece strap Coupling strap Reins 1 1 2 2 1 1 1 1 1 1 1 2 1 1 2 1 1 1 1 1 1 2 1 1 2 Snaffle bit l . . Halter, complete, consists of: Crown strap... Cheek piece Crown chape Nose band . Chin strap ^ Throat band . . . Throat strap Halter square Tie rope . . ... Martingale, complete, consists of: Martingale Cincha strap Saddle, complete, consists of: Cinchas with reinforces and loops Cinchas without reinforces and loops 1 1 2 1 1 2 2 1 2 1 i 2 2- 1 2 1 2 Lead rein roller and strap 1 2 1 1 2 2 1 2 1 2 2 1 2 Quarter straps, side, including rings and safes Quarter strap, pommel 2 1 1 2 3 1 2 1 1 2 3 1 Quarter strap' cantle - Cincha strap .. . Coat strap 33 -inch (pommel) Coat strap, 45-itich (cantle) Coat strap 69-inch Saddletree leather covered ... 1 2 2 i 2 2 Stirrups model of 1912 Stirrup straps Saddlebags pairs Saddlebags, side straps Traces lead, model of 1908 2 Consists of: 1 trace body It "ace co ver ' 3 links 1 chain 1 tog r le i 2 sockets 2 cones 2 filler trieces . . . 1 Twenty curb bits and chains per battery are issued for use in place of snaflfie bits with fractious horses. 151 COMPONENT PARTS Continued. Wheel. Lead. Property classification. Near horse. Off horse. Near horse. Off horse. Class. Sec- tion. Traces wheel model of 1908 2 2 IV a ' Consists of: 2 sockets 2 links 2 cones 1 ring 2 1 2 1 2 Whip 1 Sweat leathers f 2 1 Blanket l 1 1 1 In submitting and in filling requisitions, unless it is specifically stated that saddle blankets are wanted, they will not be included. THE CARE AND PRESERVATION OP LEATHER. Attention is invited to the following: " It is forbidden to use any dressing or polishing material on the leather accouterments or equipments of the soldier, the horse equip- ments for cavalry, or the artillery harness except the preparations supplied by the Ordnance Department for that purpose." (A. R. 293 of 1913.) REASON FOR OILING LEATHER. Leather, as it comes from the tannery in manufacture, is hard, rough, brittle, inflexible, and readily absorbs water. To remove these undesirable qualities and render the leather soft, pliable, flexible, and impervious to water, to increase the strength and toughness of the fiber, and to give the leather such a surface color and finish as will make it most sightly and suitable for the purpose for which intended, the manufacture is continued by hand stuffing it with a dubbing made of pure cod-liver oil and tallow, which the expe- rience of curriers has shown to be the best material for this purpose. This dubbing is thoroughly absorbed by the leather, penetrating it completely, and is not merely limited to the surface. The russet leather now used by the Ordnance Department in the manufacture of all leather equipments is pure oak tanned, of No. 1 tannage and finish, hand stuffed with a light dubbing made of pure cod-liver oil and tallow to preserve the leather, the dubbing being so sparingly used that the oil will not exude. This leather as it comes from the manufacturer contains enough oil to materially improve its 152 quality and prolong its life, but not enough to soil the clothing if the equipment is properly cared for. No oil whatever is added to the leather in the manufacture of the equipments at the Government arsenals. CARE OF KUSSET LEATHER. Leather equipments which have become wet should be dried in the shade. Wet leather exposed to the direct rays of the sun or to the heat of a stove or radiator becomes hard and brittle. When russet-leather equipments become soiled in service they should be cleaned by carefully washing the leather with a sponge moistened with a heavy lather made of clean water and Castile or Frank Miller's soap, and then rubbing vigorously with a dry cloth until the leather is completely dry. If the leather becomes harsh, dry, and brittle from exposure to water or other causes, clean as above described, and while the leather is still slightly moist apply an exceedingly light coat of neat's- foot oil by rubbing with a soft cloth moistened (not saturated] with the oil. If it is found that too much oil has been used, the surplus can be readily removed by rubbing with a sponge moistened with naphtha or gasoline. But these oils are not issued for this purpose. Where a polish is desired, the leather should first be thoroughly cleaned and then the leather polish or dressing supplied by the Ordnance Department should be applied sparingly and thoroughly rubbed in with a soft, dry cloth. Scars, cuts, or abrasions of the leather may be improved in appearance but not obliterated by similar use of the leather polish. Russet leather may be cleaned, oiled, and polished as described above, but it should be noted that if more than a light coat of oil be given the leather will be greatly darkened and will quickly soil the clothing. No method of cleaning will restore the original light color of the leather or remove stains or discolorations. CARE OF BLACK LEATHER. To clean and dress black leather, wash it in water (lukewarm preferred) with castile soap. An old horse brush will be found very satisfactory for applying the soap and water. Dry in the shade; when almost dry, apply the blacking, rubbing it in thor- oughly. Dry in the shade and then apply neat's- foot oil with a sponge or rag, rubbing in well until the leather is soft and pliable. When dry, a certain amount of oil and blacking will exude from the leather ; this should be rubbed off with a drv cloth. PLATE XXX. 153 SIGHTS. The instruments provided for sighting and laying the piece in- clude a line sight, a rear sight, a front sight, a panoramic sight, and a range quadrant. LINE SIGHT. The line sight consists of a conical point as a front sight and a V notch as a rear sight; the former is screwed into the locking hoop, and the latter is attached to the breech end of the jacket; together they determine a line of sight parallel to the axis of the bore, useful in giving general direction to the gun. FRONT AND REAR SIGHTS. The front and rear sights are for general use in direct aiming. They consist of a front sight carrying cross wires and a rear sight of the peep variety. The length of the line of sight is 36.75 inches; its height from the ground with gun at elevation is 44.9 inches. The sights are supported from the cradle; the peep of the rear sight is in such a position as to come opposite the eye of the gunner seated upon the left trail seat. THE FEONT SIGHT. The front sight complete consists of the front sight proper, the front-sight holder, the front-sight bracket sleeve, the front-sight bracket with spring catch riveted on, and two split pins; that is, it includes all parts except the front-sight bracket support. The front-sight bracket support is riveted to the cradle in front of the shield. The lower end of the bracket fits into a socket in the bracket support. In sighting position the bracket projects from the cradle toward the left, but for traveling it is arranged so that it may be swung out of the way of a cannoneer upon the seat. It is held in either position by the engagement of the spring catch in notches in the front-sight bracket support socket. The front sight proper consists of a pair of cross wires mounted in a ring. This ring is secured, with cross wires at an angle of 45 to the horizontal, in the circular hole through the front-sight holder. The front-sight holder has the shape of an eyebolt ; its shank screws into the top of the front-sight bracket sleeve, which screws over the upper end of the front-sight bracket. When adjusted, rotation of the front-sight holder in the sleeve or of the sleeve on the front-side bracket is prevented by split pins. THE EEAR SIGHT. [Plate XXX.] The rear sight includes all parts except the rear-sight bracket support and the panoramic sight. The rear-sight bracket support 154 . is riveted to the cradle and has a socket into which the lower end of the bracket is secured by a nut, lock nut, and split pin. The upper end of the rear sight bracket is provided with circular guides cut with the line of sight, gun at elevation, as an axis, and upon these guides a shank socket for the shank or stem of the sight is mounted. In a support forming part of the shank socket is a leveling screw with threads engaging the segment of a worm wheel cut upon the rear- sight bracket guides. A spirit level is mounted upon the shank socket. This arrangement enables correction to be made for differ- ence of level of wheels, since turning the leveling screw revolves the shank socket and with it the shank about an axis parallel to the axis of the bore. A shank-socket cover is provided to strengthen the shank socket. The latest type of shank socket is made of bronze and the leveling-screw support is made integral with it. The sight- shank cover has two lugs on its inner surface which support springs and sleeves. These sleeves are pressed by the springs against the shank and force it against the walls of the shank socket, thus taking up lost motion. The shank consists of a steel arc whose center is the front sight; it slides in guides in the shank socket and is moved up and down in elevation by a scroll gear seated in a boss upon the shank socket and engaging in a rack cut upon the right face of the shank. A German-silver range strip fits in a dovetail seat cut in the rear face of the shank, the index for the scale being placed upon the upper rear corner of the shank socket. The range strip is graduated in yards up to 6,500 ; the smallest division is 50 yards, but smaller sub- divisions may readily be made with the eye. The scroll gear is held in mesh with the rack on the shank by the scroll-gear spring. Large movements of the shank may be quickly made by pulling the scroll-gear handle out far enough to disengage the scroll gear from the rack and then sliding the shank through the shank socket by hand. To the left side of the shank is riveted the elevation-lever holder, and in this holder is mounted a spirit level with axis parallel to the line joining the peep and front sights. This level enables quadrant elevations to be given by setting the sight at the desired range and moving the gun in elevation until the level bubble is brought to the center, provided the target and gun were on the same level; i. e., angle of sight = 300. The shank is fashioned into a deflection guide and mounting for the peep sight and is prolonged upward to form a support for the panoramic sight. The peep-sight guide is located in a transverse opening in the shank and is perpendicular to the shank and to the line of sight. The peep sight is clipped to this guide and is traversed along it by the peep-sight screw. The latter passes through a tapped IS 5^ JN \ I > i ^ N 1 I) V k t r II X' ^ ^ H kfi K ^ ^ 1 SJ ^ T>! \ e ^c., of 360. The alternate divisions of the main scale are numbered in a clockwise direction 0, 2, 4, etc., to 62, inclusive. In reading the deflection scale, therefore, hundreds are read directly from the main scales and tens and units from the worm index. At the line of sight is parallel to the vertical plane through the axis of the gun; at 16 (or 1,600 mils) it is perpendicular to that plane and pointing directly to the right, etc. The worm index forming the micrometer scale is secured on a coned seat on the end of the worm by a nut and is held against rotation on its seat by friction. This arrangement permits the of the worm index to be set opposite the index mark on the casing without movement of the worm in adjusting the sight. The worm is held in contact with the worm gear on the azimuth circle by a spring and is arranged so that it may be disengaged from the worm gear by movement of a worm-box eccentric lever. When disengaged, the line of sight may be rapidly oriented to approximately the desired direction, the worm then thrown into gear, and finer adjustments made by turning the worm knob. 158 All panoramic sights have been made interchangeable, so as to fit in seats. The following device for illumination of the crosslines of the reticule of panoramic sights is used. A small slit is cut in the eyepiece elbow and the reticule cell on the side of the sight next the gun. A shutter is provided which encircles the eyepiece elbow opposite the slit, affording means for closing. On some sights this shutter is provided with a trans- parent celluloid window to prevent the entrance of dust. On the later sights a glass window is fitted in the side of the eyepiece. For illumination at night electric flash lights are used. They should be held close to the illuminating slot or window. PANORAMIC SIGHT, MODEL OF 1915. [Plate XXXII.] The panoramic sight is a vertical telescope so fitted with an optical system of reflecting prisms and lenses that the gunner Avith his eye at the fixed eyepiece in a horizontal position can bring into the field of view an ^object situated at any point in a plane per- pendicular to the axis of the telescope. The rays coming from the object are reflected downward from the rotating head prism into the rotating prism. The rotating prism rectifies the rays ; after their passage through the achromatic objective lens, the lower reflecting prism reflects them in such a way that there is presented to the eyepiece a rectified image, which the eyepiece magnifies. The peculiarity of the rotating prism is that upon rota- tion about its longitudinal axis the image of the object seen through it turns with twice the angular velocity of the rotating prism. The rotating head prism and rotating prism are so mounted as to rotate about this axis, the rotating prism following rotating head prism with one-half of the angular velocity of the latter, the image always remains as it would appear to one observing it directly with an ordi- nary telescope. The image formed by the achromatic objective lens would then be reversed and inverted. The rays are cross reflected to the opposite sides of the axis by the inclined faces of the lower reflecting prism, thus correcting the reversal. The combined action of the rotating head prism, the rotating prism and lower reflecting prism and the nature of action varying with different positions of the prisms provide for the correction of the inversion of the image. The rotating head prism and lower reflecting prism as shown in position on Plate XXXII act as parallel reflectors and they without the lens system would present an erect image. The rotating prism, however, inverts the rays and corrects the inversion produced by the achromatic objective lens. It will be noted that the PLATE XXXII. 159 effect would be the same whether the rotating prism occupies the same position shown on the plate or be revolved 180 from that position. The rotating head prism must be turned through 360 to get a posi- tion of 180 for the rotating prism. If the rotating head prism is ro- tated through 180, the rotating prism and lower reflecting prism would form reflectors set at right angles, and would give, without the lens system, an inverted image, and in conjunction with the lens system an erect image. The rotating prism in this case will occupy a position 90 from that shown on the plate, in which position it causes no inversion but counteracts the inversion produced by the lower reflecting prism. The instrument has a magnifying power of 4 and a field of view of 10. The principal parts of the panoramic sight are the rotating head mechanism^ the elevation device, the azimuth mechanism, the rotating prism mechanism, the deflection mechanism, the shank and the eye- piece. The rotating head mechanism consists principally of the rotating head, rotating head prism, rotating head prism holder, prism holder cover, elevation index support, prism shield, and rotating head cover. The rotating head forms a housing for its movable parts, and pro- vides seats for the elevation- worm bushing and rotating head prism holder. The front opening of the rotating head is closed by the prism shield which forms a dust guard. The bottom threaded seat of the rotating head screws upon the upper end of the azimuth worm wheel and is locked in place by four azimuth scale retaining ring screws. Upon the rear face of the rotating head is engraved a scale which is used for measuring the elevation of the rotating head prism holder which retains the rotating head prism and has an index mark upon the projection which coincides with the graduations of the elevation worm micrometer head. The rotating head prism is mounted within the rotating head prism holder between the prism support front, prism support bottom, and prism support back, and secured in position by the rotating head prism spring which bears upon the prism support back. The rotating head prism is protected on the right side by the prism holder cover and on the left side by the elevation index support. The movement of the rotating head prism holder is limited by the stop screw which slides in an elongated slot in the rotating head prism holder. The prism shield is held within the rotating head by the prism shield retaining piece, which is in turn secured by two prism shield retaining piece screws. The prism-holder cover screws into its threaded seat located in the right side of the rotating head prism holder and locked in position by the prism-holder cover screws. 160 The rotating head cover screws into its threaded seat located in the right side of the rotating head and held in place by the rotating head cover screws. The exterior of the rotating head cover has two small holes for teat wrench, and engravings " Field 10 " and " Power 4 " are located on the exterior surface. The elevation-index support screws into its threaded seat located in the left side of the rotating head prism holder and secured in place by the elevation-index support screw. The small holes in the exterior surface allows the use of teat wrench to enable the elevation- index support to be screwed in place. The support retaining ring retains the elevation-index support with rotating head prism holder within the rotating head and is locked in position by the support- retaining ring screw. The elevation index is held upon the elevation-index support by the two elevation-index retaining screws. The arrow, engraved upon the German silver piece which is dovetailed in the elevation index, coin- cides with the graduations of the scale engraved upon the rear face of the rotating head. The elevation device consists principally of the elevation segment, elevation worm, elevation-worm bushing, elevation-worm retaining nut, and elevation-worm micrometer head. The elevation segment is held in its seat, provided in the rotating head prism holder, by the segment lock pin. The elevation worm is mounted eccentrically within the elevation- worm bushing, which when turned provides an adjustment to take up the wear between the worm threads and the worm teeth of the elevation segment. The elevation- worm bushing has a screw-driver slot in its lower end which is used for adjusting and is retained in position by the eleva- tion-worm bushing clamp plug, which is secured by the bushing clamp-plug screw. The elevation- w y orm retaining nut retains the elevation-worm bush- ing and elevation worm lengthwise within the rotating head. The screw-driver slot, in the top of the elevation-w r orm retaining nut, is used for adjusting and is locked in position by the elevation- worm retaining nut screw. The elevation-worm micrometer head is held upon the upper slotted end of the elevation worm by the locking screw. The scale, engraved upon the periphery, is graduated into 100 equal divisions, numbered every 10 divisions. The upper exterior diameter of the elevation- worm micrometer head is straight knurled to facilitate turning. One complete revolution of the elevation- worm micrometer head is equal to the distance between each graduation upon the scale on the rear face of the rotating head. 161 The open sight is constructed of bronze plate bent to shape having an arm projecting out at each end, each arm containing a hole. A bronze knee is soldered to the interior of the front projecting arm over the center of the hole in such a manner to form a sight which is used for quick sighting. The open sight is secured to the rotating head cover by two open sight retaining screws. The principal parts of the azimuth mechanism are the azimuth- worm wheel, azimuth worm, azimuth-worm bushing, azimuth-worm wheel support, azimuth-worm wheel cover, worm knob, azimuth micrometer, and azimuth scale. The azimuth scale is retained upon its bearing, provided on lower end of the rotating head, by the azimuth-scale retaining ring which in turn is secured by four azimuth-scale retaining ring screws. The four elongated holes in the azimuth scale provide for adjusting. The scale, engraved upon the lower, exterior diameter, is graduated into 64 equal divisions, numbered every 2 divisions. The azimuth-worm wheel cover forms a housing for the movable parts of the azimuth mechanism and provides seats for the azimuth- worm bushing and deflection worm wheel and support ring. The arrow, engraved upon the azimuth index which is dovetailed in the upper exterior diameter of the azimuth-worm wheel cover, coincides with the graduations of the azimuth scale. The scale engraved upon a boss on the rear face of the azimuth-worm wheel cover is used for measuring the deflection of the object. The felt washer, which is retained in its seat, is located in the upper end of the azimuth- worm wheel cover, and provides for sufficient fric- tion between the rotating head and the azimuth-worm wheel cover. The azimuth-worm wheel support spring tends to retain the azi- muth-worm wheel upon the azimuth worm wheel support. The gear teeth of the lower part of the azimuth-worm wheel mesh with the rotating head pinion, which upon rotation moves the rotat- ing head mechanism. The lower part of the azimuth-worm wheel support screws into its threaded seat provided in the upper part of the shank. The azimuth worm is mounted eccentrically within the azimuth- worm bushing, which in turn has the azimuth- worm lever secured to it by the azimuth-worm lever screw. The bushing spring is pro- vided for retaining the azimuth-worm bushing in positionn when the azimuth worm is in mesh with the azimuth-worm wheel. The azi- muth-worm lever is so designed and arranged upon the azimuth- worm bushing to form a throw-out device for the azimuth worm. The lever spring is provided for taking up all lost motion that ap- pears lengthwise in the mechanism. The worm knob is secured upon the end of the azimuth worm by a steel taper pin, the periphery be- 10261417 14 162 ing straight knurled to facilitate turning. The arrow, engraved upon the German silver piece, which is dovetailed in the end of the azimuth-worm bushing, coincides with the graduations of azimuth micrometer. The azimuth micrometer is held on the slotted end of the azimuth worm by the locking screw. The scale is divided into 100 equal divisions, numbered every 5 divisions. One complete revo- lution of the azimuth micrometer is equal to the distance between each graduation on the azimuth scale. The rotating prism mechanism consists principally of the rotating prism, rotating prism holder, rotating prism supporting sleeve, ro- tating prism pinion, and rotating prism block. The rotating prism is of rectangular cross section, mounted and retained in position within the rotating prism holder by rotating prism block which is secured by the rotating prism set screw. The rotating prism holder is seated in the upper section of the rotating prism supporting sleeve. The rotating prism pinion is driven upon the pinion shaft. The rotating head pinion is driven upon the hub of the rotating prism pinion. The pinion shaft is mounted at both ends in its seat provided in the azimuth- worm wheel support which, upon rotation, moves the pinion shaft. This gear system is so de- signed that the rotating head moves twice the angular distance of the rotating prism holder. The principal parts of the deflection mechanism are the deflection- worm wheel and support ring, deflection worm, deflection-worm bushing, deflection dial, and worm knob. The deflection-worm wheel and support ring is seated within the azimuth-worm wheel cover by a threaded surface and then retained by three deflection- worm wheel and support ring screws. A segment, projecting downward into the shank, carries a worm wheel which meshes with the deflection worm. The deflection-worm wheel sup- port is located within the shank and against the deflection-worm wheel and support ring by two dowel pins, and secured by two de- flection-worm wheel support screws. The deflection worm is mounted eccentrically within the deflection- worm bushing which when turned provides an adjustment to take up the wear between the worm threads and the worm teeth of the de- flection-worm wheel and support ring. The deflection-worm bushing is adjusted by using the fingers upon the rear end and is restrained in position by the deflection-worm bushing clamp plug, which is secured by the deflection-worm bushing clamp plug screw. A German silver piece is primed to the rear end of the deflection-worm bushing on which is engraved three arrows with letters "R" and "L," The middle or large arrow coincides with the graduations of the deflection dial. The compensating spring is provided for taking up all lost motion that appears length- 163 wise in the mechanism. The worm knob is secured to the deflection worm by a taper pin, the periphery being straight knurled to facili- tate turning. The deflection dial is held on the front, slotted end of the deflection worm by the locking screw. The scale, engraved upon the front end, is graduated into 100 equal divisions, numbered every 10 divisions. The shank forms a body for tLe instrument and pro- vides seats for the azimuth -worm wheel support, deflection -worm bushing, and elbow. The front surface is provided with a T lug which fits into a corresponding slot in the upper end of the shank of the rear sight. Upon the rear surface is dovetailed the deflection index, which is retained in place by the deflection-index screw. The arrow engraved upon the deflection index coincides with gradua- tions upon the rear face of the azimuth-worm wheel cover. The eyepiece consists principally of the reticule, reticule cell, acro- niatic field lens, achromatic eye lens, and eye lens cell. The achromatic objective lens is mounted in the upper end of the objective lens cell. This cell is secured in its threaded seat in the upper end of the elbow by two objective lens cell retaining screws. The elbow is screwed in the' lower end of the shank and secured by the four elbow retaining screws in such a manner that its projecting aim is horizontal to the axis of the instrument. The elbow provides seats for the lower reflecting prism and the eye lens cell. The lower reflecting prism is held upon its bearing surfaces, provided in the elbow by two wedges which in turn are secured by the two wedge screws. These screws are retained by the wedge screw lock screw. The wedge screw cover is provided to retain the wedge screw lock screws in position. The wedge screw cover is secured by the wedge cover screw. The openings of the elbow upon the right and left sides are closed by the elbow covers, which are locked by the elbow cover screws. Upon the left side of the elbow is an opening through which the light is thrown upon the reticule. This opening is covered by the window to protect the interior of the eyepiece from dust and dirt. The shutter is so designed to slide over the opening in the elbow be- ing guided by the shutter stop screw and movement limited by the elongated slot. The reticule has two cross lines etched on its surface and is mounted in the forwarded end of the reticule cell which is secured in the eye lens cell by the reticule cell retaining screw. The achromatic eye lens is mounted in the eye lens cell and is sepa- rated from the achromatic field lens by the lens separator. The achromatic field lens is held within the eye lens cell by the field lens retaining ring, which in turn is locked by the field lens cell retaining ring screw. The eye lens cell is secured to the elbow by the eye lens cell retaining screw. 164 All interior metallic surfaces exposed to the refracted light are fin- ished with dull black baking enamel. All exposed optical elements, covers, and nonrotating joints are sealed with the litharge cement or equal. All German silver graduated surfaces are sandblasted and lacquered. THE RANGE QUADRANT. [Plate XXXIII.] In this carriage the elevating and traversing mechanisms being entirely independent of each other, the laying of the gun may be much simplified and the time required be considerably lessened by assigning to one gunner the laying for direction and to a second that for range. Such a division of duties is provided for by the ele- vating crank at the right side of the trail. By this arrangement the gunner on the left of the piece using the open or panoramic sight lays for direction only, while the gunner on the right trail seat gives elevations by means of the range quadrant. The range quadrant consists of the quadrant bracket, rocker, body, scroll gear, range disk, and range and cross levels with suitable leveling screws. A quadrant-bracket fastening riveted to the right side of the cradle has dovetailed guides in which the quadrant bracket fits and is held by a spring catch. Two bracket fulcrums screwed into arms on the bracket project into bearings in the ends of the rocker, assembling the latter to the bracket and at the same time permitting it a motion of rotation about an axis joining the centers of the bracket fulcrums or trunnions. As assembled, this axis of motion is parallel to the axis of the gun. A projection below the rear end of the rocker forms a seat for a leveling screw, the axis of which is in a plane perpendicu- lar to the axis of the gun. The knurled head of this screw projects to the right and its threads mesh in the segment of a worm wheel cut on the quadrant bracket. This leveling screw is thus arranged to rotate the rocker on its trunnions and, in conjunction with the cross level mentioned below, enables the quadrant to be brought into a vertical plane parallel to the axis of the gun. This construction is necessary to correct for difference of level of wheels and to give true quadrant elevations. At the front end of the rocker is the seat for a fulcrum pin, which forms the center of motion of the quadrant body. At the rear end of the rocker a curved arm projects upward which has circular racks cut on its front and rear edges. This curved arm passes through a slot in the body and the centers of the racks coincide with its center of motion. The body, as stated above, is pivoted on the rocker. Its rear end affords a housing for the scroll gear and a seat for the range disk. The scroll gear meshes with the rear circular rack of the rocker. The PLATE XXXIII. n " . 165 scroll gear is actuated by a knurled handwheel, which projects upward and to the rear. Turning the handwheel rotates the body on its fulcrum pin, moving its rear end up or down on the curved arm of the rocker. The scroll gear is pressed against its rack by a spring ; large changes of position of the quadrant body may be made by pulling the handwheel out to disengage the scroll gear from the rack and then moving the body by hand to the desired position. The range disk is assembled on a steel shaft seated in the quadrant body ; this shaft carries a pinion which meshes with the front circular rack on the curved arm of the quadrant rocker. The range disk is held between the inner and outer friction disks. The outer friction disk on quadrants is split radially and has a serrated edge. This combined with the slight spring allowed in the outer friction disk forms an adjustable yet secure lock for the range disk. A nut screwed on the pinion shaft clamps the disks in position, and a lock screw in the end of the pinion shaft prevents the nut from unscrewing. The inner friction disk is connected to the pinion shaft by lugs projecting into the pinion shaft collar. A spiral spring, the tension of which serves to take up any lost motion in the arrangement, is connected at its outer end to the inner friction disk by a pin. It is wound around the hub of the body and secured to the hub in a slot cut to receive it. The face of the range disk, which is visible on the right side of the quadrant, is graduated to 6,500 yards for model of 1902, and 8,000 yards for model of 1916. The caliber of gun for which the range disk is made is engraved on the face of the disk. The least division is 50 yards, and the scale is dimensioned at each 500 yards. Divisions smaller than 50 yards may be readily made with the eye. The range disk is always in gear through the pinion ?haft with the rack on the curved arm of the rocker, and any change in position of the quadrant body with reference to the rocker is registered by the disk. The elevation level holder is seated on the forward part of the body, with its front end pivoted on the fulcrum pin of the latter. Its rear end is finished with a segment of a worm wheel, cut with the fulcrum axis as a center, which meshes with a vertical micrometer screw seated in the body. The amount of the relative motion of the elevation level holder and body is measured by a level scale, consist- ing of an ordinary circular scale dovetailed in the body with the level index on the elevation level holder supplemented by a level microme- ter disk on the upper end of the micrometer screw. The level scale is graduated in sixty-fourths of the circumference, and one complete turn of the screw moves the level holder through one of these divi- sions. The level micrometer disk on the head of the micrometer screw has 100 divisions, so that one of these divisions corresponds to one mil. The divisions of the level scale are marked 2, 3. 4, and 5, 166 and in connection with the level micrometer disk are read 200, 300, etc., plus the indication of the latter. The 3 or 300 mark corresponds to the mean or zero position of the elevation level holder. The level holder is fitted with two spirit levels of a sensitiveness of 0.1 inch, which equals five minutes of arc. The longitudinal or range level is located so that its axis is parallel to the axis of the gun when the level scale is set at 3 and range disk at zero. The axis of the transverse or cross level is perpendicular to that of the range level and also to the plane of motion of the quadrant body. The cross level in connection with the leveling screw enables the rocker and body to be kept vertical. The range level in connec- tion with the elevation-level holder and its level screw is used as a clinometer to correct the range-disk readings for angle of site ; in con- nection with the body it is used as the range quadrant level. For purposes of reference, these levels are designated as the cross level and the range level, and their respective screws as the leveling screw and micrometer screw; the scale pertaining to the latter screw is called the level micrometer disk. The range level is also referred to at times as the quadrant or angle of site level. USE OF SIGHTS AND QUADRANTS. By construction and method of mounting with longitudinal and cross levels on the rear sight, the panoramic sight forms a horizontal angle measuring instrument. These angles are read directly from the deflection scale of the sight in units, mils, equivalent to -g-^nnr of a com- plete circle, or 360. USE OF THE PANORAMIC SIGHTS, MODELS OF 1904 AND 1915. For direct aiming. Set the rear sight at the required elevation and correct for difference of level of wheels; set off the desired deflection on the azimuth circle of the panoramic sight ; bring the crosslines of the sight upon the target by means of the elevating and traversing devices of the carriage. For imparting the approximate initial direc- tion the line sight may be used with advantage. In using the model of 1915 sight for direct fire, care must be taken that the rotating head be set at 300 mils and the de-flection mecha- nism at 0. For indirect aiming. Set the rear sight at the required elevation and make correction for difference of level of wheels,; set the azimuth circle of the panoramic sight at the deflection ordered. Lay the gun for deflection by directing the vertical line of the panoramic sight at the auxiliary aiming point, the elevation of the gun being given by using the range quadrant. The angle of deflection to be set off on the azimuth circle of the panoramic sight is the same as the angle 167 made by joining the target and the auxiliary aiming point with the sight. For measuring ranges. Distances or ranges may be roughly cal- culated from readings made by two panoramic sights mounted on their guns, as follows : Direct the guns on the target ; then sight the panoramic sights on each other. The angle at the target subtended by the line connecting the two guns is then 3,200 mils minus the sum of the actual angles in mils measured at the guns. If B is the distance between the guns in yards, then range equals. B multiplied by 1,000 divided by the number of mils in the angle at the target. The accuracy of this method increases as B becomes smaller so. long as the instruments can be read correctly. USE OF THE RANGE QUADRANT. To give quadrant elevations with the range guadrant. Set the- range disk for the desired range by turning the scroll gear handle,, and correct for difference in level of wheels; correct for angle of site on the scale of the elevation-level holder ; bring the bubble of the range level to the center by elevating or depressing the gun. The gun will then have the elevation (corrected for angle of site) correspond- ing to the range. CARE OF SIGHTS AND QUADRANTS. Whenever convenient, and especially when in garrison and not ini use, the front and rear sights with the range quadrants and pano- ramic sights should be removed from the carriages and kept in some dry place, as in the barracks' storeroom or office. CARE OF THE FRONT AND REAR SIGHTS. For traveling the front sight is covered by the duck cover supplied for the purpose ; and by means of the spring catch at the base of the bracket, it is turned 105 from its firing position to the rear and locked to the front-sight bracket support. The shank is withdrawn from the shank socket, covered with the covet for shank and placed in the sight box provided for it in the trail of the carriage. A duck cover, called the cover for rear-sight bracket, is provided to protect the surfaces of the shank socket and should be slipped over the shank socket when the shank is removed. All parts of the shanks and shank sockets should be kept clean,, free from rust, and lightly oiled. When stored or not used for short periods, they should be thoroughly cleaned and well coated with light slushing oil. Should any part become rusted, it should be 168 carefully cleaned by softening the rust with coal oil and rubbing with a soft pine stick. In handling all parts of the sights care must be exercised to avoid injuring them by dropping, striking them upon or with other parts, etc. The front-sight bracket must not be used by the cannoneers as a handle to assist in mounting upon or dismounting from the axle seat or otherwise. To clean the joint between the rear-sight bracket and the shank socket, drive out the taper pin from the end of the leveling screw and remove the leveling screw. Disassemble the shank socket from the rear-sight bracked, clean all parts, and oil them with sperm oil. Assemble in the reverse order. Oil the leveling screw from time to time through the oil hole pro- vided in the rear-sight bracket. For instructions for the replacement of level vials see instructions given under the heading " Care of the range quadrant." CARE OF THE PANORAMIC SIGHT, MODELS OF 1904 AND 1015. These sights are delicate instruments and must not be subjected to any rough usage, jars, or strains. In firing they remain in position on the carriage; in the field, when not in use, they are kept in the padded leather cases prepared for them on the rear of the main shield. To obtain satisfactory vision, the glasses must be perfectly clean and dry. The T lug on the sight and the slot forming its seat should be kept lightly oiled as a preventive of rust. The worm and worm rack should be oiled with vaseline. When dust accumulates on the pointers it should be removed by a fine camel's-hair brush in the hands of an experienced person. To disassemble the worm mechanism of the model of 1904 sight for cleaning, throw out the worm-box eccentric lever, disengaging the worm from the worm gear of the azimuth circle. Insert a pin in the radial hole in the spring-box pin. Throw. the worm-box eccentric lever back and engage the worm .in the azimuth circle. Push the spring box toward the worm knob about three-eighths inch and then lift it straight out. Take out the eccentric-lever stud and remove the worm-bcx eccentric lever. Pull out the dowel '. the worm-box pin with a pair of .pliers and drive out the worm-box pin. Then pull out the worm box and worm complete. The worm may be cleaned without further disassembling. Assemble in reverse order. The teeth of the worm wheel may be cleaned without disassembling the hood. To clean the rotating-head window and the front face of the rotating-head prism, unscrew the window cell in the rotating head. Do not remove the rotating-head window from the window cell. 169 To clean the reticule and eyepiece lenses, remove the screw holding the eyepiece to the eyepiece elbow and unscrew the eyepiece. To disassemble the lenses, remove the set screw on the underside of the eyepiece and unscrew the eye-lens cell. The field lens is held in place by a retaining spring, both of which may drop out as soon as the eye-lens cell is disassembled. In assembling note that the flat surface of the field lens of the eyepiece is placed next to the reticule. Do not remove or change the adjustment of the reticule. Its rear surface may be cleaned with a camel's-hair brush after the eyepiece has been removed. In panoramic sights of serial numbers after No. 752 the exposed optical elements and all nonmoving joints are sealed and no attempt should be made to remove them. For serial numbers 873 and up. the slight change in the appearance and construction of the elbow and rotating head is made for the purpose of making these parts dust and moisture proof. CARE OF THE RANGE QUADRANT. The directions for the care of the range quadrant are practically the same as those for the care of the different sights. The parts should be kept clean, free from rust^ and bearings lightly oiled. When stored they should be coated with light slushing oil. To clean the micrometer screw, remove the screw in the center of the micrometer dial, turn the micrometer screw until the dial is forced off; drive (away from gun) the taper pin holding the screw bushing. Pull out the screw bushing, clean, oil with a heavy oil. and assemble in the reverse order and adjust. Extra glass level vials assembled in brass tubes, to replace broken vials in sights and range quadrants, except for the range levels of quadrants, will be issued on requisition. In case the range level of the range quadrant requires replacement the range quadrant will be turned in to an arsenal designated by the armament officer. Only ordinary tools, such as a hammer and a punch or a piece of wire, are required for the removal of pins from level caps in order to replace vials. All pins on level caps are driven in toward the center of the instrument. They should be driven out in the opposite direc- tion. Four adjusting screws in the vial tubes are used for adjusting the tubes in their holders. ADJUSTMENT OF SIGHTS AND QUADRANT. The sights are correctly adjusted when, at zero elevation and de- flection, the line of sight is parallel to the axis of the bore. The range quadrant is correctly adjusted when, with the range disk set at zero, level scale set at 300, and axis of gun horizontal and corrected for difference of level of wheels, the level bubble of the 170 range level stands in the center of its vial. In adjusting sights, the panoramic sight should first be corrected. If the rear sight is ad- justed first, it will require readjustment if the subsequent adjustment of the panoramic sight causes a change in position of the rear : sight range strip. TO ADJUST THE PANORAMIC SIGHT, MODEL OF 1904. Direct the panoramic sight by means of the worm knob and scroll gear handle until its line of sight is parallel to the axis of the bore. The method of determining when this condition of parallelism exists is described hereafter. Without disturbing the direction of this line of sight, move the worm index of panoramic sight and the range strip of the rear sight until the zero marks come opposite their respective indices. The worm index may be moved after loosening the nut on the end of the worm. This nut may be loosened by the combined teat wrench and screw driver issued for the purpose. If the worm index can not be readily removed, grasp the sight by the worm index, release the worm from the worm gear of the azimuth circle, and gently tap the exposed end of the worm with a small piece of wood or soft metal. To locate the index of the panoramic sight opposite the zero of the scale, loosen the four screws that hold the movable index cover in place and move this cover until the index is properly located; then tighten the screws. Movement of the range strip of the rear sight is made possible by a dovetail slot in the shank in which the range-strip screw can be moved when the nut has been loosened. TO ADJUST THE PANORAMIC SIGHT, MODEL OF 1915. Should backlash or lost motion appear lengthwise within the eleva- tion device, it can be removed by loosening the elevation-worm retaining-nut screw, setting up on the elevation-worm retaining nut and then tightening up on the elevation- worm retaining-nut screw. To remove backlash between the threads of the elevation worm and worm teeth of the elevation segment, loosen the bushing clamp plug screw which releases the elevation-worm bushing-clamp plug, and then turning the elevation bushing, in which the elevation worm is eccentrically mounted, so as to bring the elevation worm closer in contact with the worm teeth of the elevation segment. The elevation- worm adjusting clamp plug must be firmly clamped after adjusting by tightening up on the bushing clamp plug screw to secure the elevation-worm bushing against rotation. After adjusting, should (he zero, upon the elevation-worm micrometer head not coincide with its index when the elevation index coincides with the graduations of the scale upon the rear face of the rotating head, it can easily be remedied by the loosening up on the locking screw and turning the 171 elevation- worm micrometer head until the zero just coincides with its index, after which it must be firmly secured by tightening up on the locking screw. Backlash between the threads of the azimuth worm and the worm teeth of the azimuth worm wheel is taken up by the bushing spring. The four elongated holes in the azimuth scale afford means for adjusting when its zero does not coincide with the arrowhead upon the azimuth index when the zero of the deflection scale, upon the rear of the azimuth worm-wheel cover, coincides with arrowhead upon the deflection index. After this adjustment is made the azimuth micrometer should be inspected similar to that of the elevation-worm micrometer head. Backlash, that appears between the threads of the deflection worm and the worm teeth of the deflection worm wheel and support ring, can readily be removed when the method of adjusting similar to that of the elevation device is followed out. TO ADJUST THE FRONT AND REAR SIGHTS. Set the range strips at zero elevation and move the peep sight and the front sight until the line of sight is parallel to the axis of the bore. The method of determining when this condition of parallelism exists is given below. Now shift the deflection scale on, the rear sight, after loosening the two screws, until its zero is opposite the index on the peep sight. Movement of the front sight is accomplished by turning the front- sight bracket sleeve, after first removing the split pins. TO ADJUST THE RANGE QUADRANT. Elevate or depress gun until its axis is horizontal, correct for dif- ference of level of wheels, set the level scale of the quadrant at 300, then turn the scroll gear handle until the range-level bubble is cen- tered. Now turn the range disk of the quadrant until its zero coin- cides with the range index. The range disk is held between two friction disks secured by a nut and lock screw and it is only necessary to unscrew these to release the disk and correct its position. To test the horizontality of the gun use the testing level issued for that pur- pose. This level has two arms perpendicular to each other, and a level vial is inserted in each arm. As the faces of the breech and the muzzle are perpendicular to the axis of the bore, the horizontality of the axis of the bore may be determined by placing one of the arms of the testing level against the face of the breech or muzzle and elevating or depressing the gun until the bubble in the level of the other arm is in the center. Then apply the other arm to the same face and the bubble in the first arm should also be in the center of its vial. If not, the testing level requires adjustment. 172 VERIFICATION OF PARALLELISM OF LINES OF SIGHT AND AXIS OF BORE. The adjustment of the sights and range quadrant is of such impor- tance and should be verified so frequently that battery commanders will find it advantageous to make permanent arrangements for such verification. The leveled supports constituting the carriage emplace- ment should preferably be of stone. The site of the target (fig. 1) should be prepared, and the exact locations of the target and hori- zontal reference points permanent!} 7 marked. If these arrangements are properly made, subsequent verifications of sights and range quadrants will become a simple matter. nsunct A target of dimensions given in figure 1 is placed in a vertical posi- tion perpendicular to the line of sight, at such a height that the point " bore " is at the same height as the axis of the bore of the gun. The verticality of the target is assured by a plumb line attached at A, coinciding with the vertical line AB. The carriage is placed with the wheels and trail resting upon solid supports of wood or stone, the surfaces of which have been carefully leveled so as to bring the axle axis horizontal. Now direct the gun so that the prolongation of the axis of the bore, as determined by the 173 bore sights, pierces the target at the proper point; the lines of sight of the open and panoramic sights are then adjusted in direction by the means explained above until they pierce the targets in the points marked, respectively, " open " and " panoramic." The axis of the bore is determined and prolonged by means of bore sights. In the absence of such means a breech-bore sight may be made from an empty cartridge case from which the primer has been removed ; a piece of paper should be pasted over the primer seat and a .pinhole made in its exact center to serve as a peep sight. If the cartridge case does not completely fill the bore it should be shimmed all around with tissue paper until it does so. For a muzzle-bore sight use should be made of the traces of the horizontal and vertical planes containing the axis of the bore, which are marked on the muzzle of the gun. Fine threads or hairs stretched across the muzzle to coincide with these lines form a good bore sight, and the ends of such threads may be conveniently fastened to a cloth strap buckled around the muzzle of the gun. In the field, where from lack of time or proper facilities the method just given can not be followed, the adjustment of the sights may be verified by bringing the lines of sight at zero elevation and deflection to bear upon some sharply defined point of a distant object. At such a range (for instance, 2,000 yards or more) the parallax may be neglected, and if the sights are correctly adjusted the lines of sight and the prolongation of the axis of the bore will sensibly pass through the selected aiming point. ADDITIONAL TESTS. After the sights and range quadrant are adjusted they should be subjected to the following tests to insure their accuracy at extremes of elevation and azimuth : (a) With carriage level and gun and sights at zero elevation and deflection, the lines of sight and axis of bore prolonged pierce the target (fig. 1) in the proper points. (&) The gun is then moved to its maximum elevation; as the sight elevation is altered, the lines of sight should follow the vertical lines through the same points of the target (fig. 1). (c) With conditions as in (erty cation. guns, cais- sons). Article. Where carried. Class. Sec- tion. 4 Spare parts for guns and gun carriages. Carried in store wagon g . . . do 2 Hub liners In batterv wagon 2 In miscellaneous spare parts chest. . . 1 In store wagon 200 Split pins assorted Carried in leather pouches for spare 2 parts. On store wagon 2 In battery wagon 1 4 For gun if model of 1902. Breech mechanism complete, including block carrier. Caps In top rear compartment of battery wagon. In leather pouch for spare parts 4 do g Cocking-lever pins ... do . g do g do g do 4 Hinge-pin catches ...do.... 4 Latch bolts .... do 4 do g Oil-hole covers with screws do 4 Pivot keys do 4 Sears ...do.... 12 Sear springs . . do 4 do 12 Trigger springs do 4 Lever-latch springs do 1 4 For guns if models of 1904 or 1905. Breech mechanism complete, including block carrier. Block latches In top, rear compartment of battery wagon. 4 Block-latch spring . 4 4 Firing springs . . IV 3 4 Firing-spring sleeves 8 4 Handy oilers, & inch (for 1905 gun only)... Hinge-pin catches 4 In leather pouch for spare parts 4 Locking bolts nuts and pins 4 Locking-bolt springs 8 4 Oil-hole covers with screws (for 1904 gun only.) Pallet pins 4 Sears . 8 Trigger-shaft detents 2 For fond fuze setters if model of 1905 M. Clamp shoe 4 Corrector-scale screw g Handle screw 2 Index 4 Plunger 4 Plunger spring In leather pouches for spare parts 4 Range-ring screw 3 Stop pins 4 Stop screw 2 Wing nut 2 0.062 by 0.47 inch steel pin 6 For hand fuze setter if model of 1912. Corrector-scale screw 4 Guide-plate lock screw .... 3 Index-bar screw 4 Index plunger 4 Index spring In leather pouches for spare parts. . . g Oil-hole screw 4 Range index 12 Range-ring screw 3 Stoo-oin screw . . . 191 Statement of total equipment of one 8-inch gun battery Continued. War foot- ing (4 Proi classif perty .cation. guns, cais- sons) Article. Where carried. Class. Sec. tion. 4 jFor bracket fuze setter. Corrector-scale screw 12 16 Housing screws and split washers * 4 4 2 Range-worm crank and knob taper pin with brass split pin. In leather pouches for spare parts . . 8 Range-ring screw 12 Split pins (0 125) 4 4 Spring 6 1 For carriages. Apron-latch complete In chest for miscellaneous spare parts 2 Apron-latch springs do 1 Apron-latch block with bolt and nut do Apron-latch pin ...do 1 Carried loose 2 Brake-rod pins In chest for miscellaneous spare pirts 1 do 1 Brake-segment rack with rivets do 3 Counter-recoil springs . i - do 3 or Counter-recoil springs: Inner In store wagon 3 Outer do 4 Cylinder-end screw In chest for miscellaneous spare parts 1 Cylinder-end stud nut . do 2 Drain-plug cylinder In leather pouch for spare parts 2 Elevating and traversing lock springs do 4 1 Elevating bevel pinion taper pins Elevating pin In chest for miscellaneous spare parts ... do 1 Elevating-screw cover with springs do 2 Filling plugs (piston rod) In leather pouch for spare parts ... 1 Firing mechanism, parts (for carriages Nos. 1 to 168, inclusive): Firing handle In chest for miscellaneous spare parts IV 3 2 Firing shafts do 1 Firing mechanism, parts (for carriages above No. 168): Adjusting screw with check nut 2 Bracket studs and nuts 1 Firing handle 1 Firing-handle bracket 1 Firing-handle hub 2 Firing-handle pins 1 Firing-handle plug 1 Firing-handle plunger 4 Firing-handle springs 1 Firing shaft [in chest for miscellaneous spare parts 2 Handle return springs 2 Shaft return springs 1 Shaft trip collar 1 Trip-collar pin 1 Trip latch 1 Trip-latch pin 1 1 Trip-latch plunger 1 Trip-latch spring 20 2 Garlock's waterproof packing, $-inch rings . Handspikes complete In leatherjpouch for spare parts In store wagon 46 Nuts, crown, special, set, consisting of 0.625 by 11 threads 2 0. 75 bv 10 threads 10 0.875 by 9 threads 2 0.875 by 20 threads 2 1 25 by 7 threads 2 1. 25 bv 12 threads Carried equally in leather pouches for 2 1.062 (1-iV) by 16 threads spare parts. 18 Nuts crown, standard set, consisting of 0.375 by 16 threads 12 0.5 bv 13 threads . . 28 1 0.625 by 11 threads... 10261, -16 192 Statement of total equipment of one 8-inch gun battery Continued. War foot- ing (4 Prpi >erty cation. *& cais- sons). Article Where carried. Class. Sec- tion. 2 2 .For carriages Continued. Nuts, hexagon, special, set, consisting of 0.187 (&) by 26 F. A. standard threads . 242 by 24 'threads 2 375 by 16 threads 1 Carried equally in leather pouches for 2 Nuts, hexagon, standard set, consisting of 19 bv 30 threads spare parts. 1 Recoil indicator 4 60 Retaining ring hasp split pins and cords... 7 Spade-edge rivets IV 3 12 1 Spring covers No. 1, with screws and washers. Spade edge fin chest for miscellaneous spare parts 1 Sponge and rammer complete 1 2 Tube-cover latch springs 1 Traversing nut " 16 Tools and accessories for limbers. Axes On limber, under chest }TT7 48 Buckets watering canvas On limber IV 9 32 Dust guards On wheels IV 3 16 Hatchets On limber in bracket on left of chest 16 Lanterns On limber , in bracket front of chest. . TXT 16 Lantern-bracket pads . . In brackets IV 4 16 Neck yokes On pole 36 Oil cans, tubular On limber in ammunition chest . ... IV 3 16 Paulins 12 by 12 feet On limber on seat as cushion | 16 IV 9 116 Picket ropes . On limber on front of chest 16 Pole props On limber in fastenings under frame 16 Shovels, short handled On limber under chest 32 Singletrees On doubletree 16 Straps: Ax 48 Grip 16 Hatchet 64 Limber-blanket front 64 Limber-blanket, rear IV 3 48 Paulin In fasteners 16 16 Pick handle Pick head 64 Picket rope upper 64 Picket rope, lower 16 Pole prop 16 Shovel handle 2 Spare parts for limbers. Ammunition-chest connection pins 2 1 Ammunition-chest door lock hasps, bolts, and springs. Ammunition-chest door lock spring In chest for miscellaneous spare parts 2 Ammunition-chest shot bolts . . 2 Doubletrees In store wagon 3 Doubletree bolts and nuts In chest for miscellaneous spare parts 2 Double tree hooks.. . .do . . 3 Hub liners In store wagon 2 Hub cap complete do 3 Limber-prop chains with handles In chest for miscellaneous spare parts 3 Lock washers do IV 3 8 Neck yokes, wooden In store wagon 2 ' Neck yokes, steel do 2 Oil cans, tubular Carried loose 4 Oil-can nozzles do 2 Padlocks, chains, clevises 2 Pintle-bearing bolts, with nuts jln chest for miscellaneous spare parts 1 Pintle with bearing complete Carried loose 2 Pintle-latch springs Carried in chest for miscellaneous 1 Pintle latches... spare parts. Carried loose . . . i 32 for horse batteries. 193 Statement of total equipment of one 8-inch gun battery Continued. War foot- ing (4 Proi classif Derty ication. guns, cais- sons) Article. Where carried. \ Class. Sec- tion. 1 /Spore parts for limbers Continued. Pintle springs Carried in chest for miscellaneous 1 Picket rope spare parts. 4 Pole bodies, complete or 2 Poles, steel do 2 Pole covers Carried loose 2 Pole ferrules, complete . IV 3 8 Pole pads In chest for miscellaneous spare parts 2 Pole props . . . 4 Singletrees do 3 Wheels, complete 3 Wheel fastenings, complete 12 Tools and accessories for caisson. Axes IV 9 24 Dust guards 12 Fuze setters, bracket IV 3 12 Fuze setter-bracket covers.. do 12 Paulins . }T\r 9 12 Pick mattocks IV 12 Shovels, long-handled 12 Spanners, caisson On caisson on left of chest 12 Straps: Ax 36 Grip 36 Paulin IV 3 12 Pick-mattock 12 Sho vel-handle 12 Spanner 12 Wrench 12 Wrenches, 0.625 and 0.75 inch . . . On caisson on left of chest 2 Spare parts for caissons. Apron hinges, complete, end 2 Apron hinges, complete, center 4 Apron-hinge pins . . In chest for miscellaneous spare parts 1 Apron latch, complete 2 Apron-latch springs 2 Brake-levers, with catches 12 Brake shoes 24 Brake-shoe tap bolts do 1 Caisson-prop chain and hook do 1 Caisson prop, with chain and hook do 3 H ub liners do 3 Lock washers ... . In chest for miscellaneous spare parts V 3 1 Lunette, with nut 2 Padlocks, chains, and clevises do 2 Pintle-bearing bolts, with nuts do 1 Pintle, with bearing, complete do 1 Pintlelatch do 2 Pintle-latch springs ' do 1 Pintle spring do 300 Splitpins 3 Wheels, complete . . 3 Wheel fastenings, complete 1 Tools and accessories for battery wagon. Carpenters' chest, with tools, set In battery wagon 1 Chest for cleaning material and small stores do IV 9 1 Chest for spare breech mechanism do 1 Chest for spare sights, containing 1 bore sight, breech IV 3 1 bore sight, muzzle 1 Double tackle block do IV 9 2 Dust guards IV 3 1 Forge coal bag IV 9 1 Filling funnel, cvlinder IV 3 1 Grindstone with frame, complete do rv 9 1 Jackscrew do IV 9 1 Marking outfit for stamping leather In cleaning-material and small-stores ] 1 Marking outfit for stamping metal... chest. ...do... X 5 194 Statement of total equipment of one <3-inch gun battery Continued. War foot- ing (4 guns 12 cais sons) Article. Where carried. Property classification. Class. Sec- tion. 9 5 3 9 9 5 9 3 9 9 5 3 9 9 9 a 5 3 9 3 3 9 3 9 3 9 3 9 9 3 9 3 3 1 1 1 1 1 1 1 1 2 2 2 2 2 2 1 1 2 1 20 20 1 1 2 1 3 1 1 1 2 2 2 1 3 2 1 1 1 1 2 1 1 11 1 1 2 1 3 Tools and accessories for battery wagon Con. Oil cans, 5-gallon . In oil-can supports IV X } IV } 'i IV IV X X X i:;: X IV IV i VII IV IV IV [ I IV IV IV IV IV IV IV IV IV IV IV Ordnance Department insignia stencil Packing chest for supplies In cleaning-material and small-stores chest. In battery wagon Packing chest for spare parts do On battery wagon Rope, 70 feet lone; In battery wagon Saddler's chest with tools set do Seal stamp . In cleaning-material and small-stores chest. In battery wagon Single-tackle block Spare wheel-hub covers On spare wheels Spring centering tools In battery wagon i Spring compressors No 1 do Stencil outfit . . . In cleaning-material and small-stores chest. In strap fasteners Straps: Grip Jackscrew do Paulin ...do Testing level and chest In batterv wagon Vise Attached to lunette frame Water buckets, galvanized steel In battery wagon Wrench, grindstone and recoil-spring as- sembling. Tools and accessories for store wagon. Bolos . . do In store wagon Bolo scabbards do Chest for miscellaneous spare parts do Crowbar *" *" Dust guards On wheels Filling funnel, cylinder In store wagon Oil cans, 5-gallon On store wagon in oil-can supports . . do Paulin, 12 by 12 feet Slush brush ... do Straps: Crowbar In strap fasteners Grip... Paulin In store wagon Spare wheel-hub covers Tools and accessories for forge Umber. Ax On limber under chest 1 Buckets, watering, canvas On limber, in bucket holder J Dust guards On wheels' Hatchet... In bracket on left of chest Hub liner driving tool In forge limber Lantern Onlimber,in bracket onfront of chest. In lantern bracket ] Lantern-bracket pad . Neck yoke On pole Oil cans, tubular On limber, in supports under chest . . On limber chest as cushion | Paulin, 12 by 12 feet Pickax On Umber foot rest ) Picket rope Pole prop On limber , 'in fastenings under frame . On limber, under chest Shovel, short-handled Singletrees Attached to doubletree Straps: Ax In strap fasteners Grip Hatchet Limber blanket, front Limber blanket, rear Pauun Pick head i In fastener . . . Picket rope, upper Picket rope, lower... Pole prop . . Shovel handle Sledge 2 for horse batteries. 195 Statement of total equipment of one 8-inch gun battery Continued. War foot- ing (4 classif jerty cation. guns, 12 cais- sons) Article. Where carried. Class. Sec- tion. 1 Tools and accessories for store limber. Ax On limber, under chest 3 In bucket holder IV 9 j On axle of limber 2 Dust guards On wheels IV 3 1 Hatchet .. On limber in bracket 1 Lantern On limber in bracket on chest front . 9 1 Lantern-bracket pad In brackets 1 Neckyoke " On pole Ij IV [3 2 Oil cans tubular On limber, in supports 1 Paulin 12 by 12 feet On limber chest as cushion 1 Pick ax On limber foot rest I ilV ro i 1 Picket rope On limber, in front of chest 1 Pole prop In fastening under frame A IV rs 1 Shovel short handled On limber under chest ... .... 1 IV 9 2 Singletrees Attached to doubletrees. 1 Straps: Ax . 3 Grip Hatchet. Limber blanket, front. . . . Limber blanket, rear TV Paulin In strap fasteners 3 Pick handle Pick head Picket rope, upper Picket rope , lower Pole prop ... . Shovel handle 4 Spare parts of accessories. Ax helves In store wagon 2 do 3 Handles, shovel, short do IV 9 4 Handles, hatchet do 4 Handles, pick ax.. do 3 Padlocks with chain clevises and bolt In battery wagon snaps. Sights and quadrants. Front sights In bracket Front-sight brackets with holders In fastenings on cradle Rear-sight brackets with shank sockets In bracket Rear-sight shanks In fastenings on cradle IV 3 Panoramic sights In case on shield Range quadrants In case on right side of trail Teat wrenches for panoramic sights In case OP shield 1 Spare sights and quadrants. Front sight, complete 1 Rear sight, complete . . . TV Panoramic sight lln spare-sights chest m battery 3 1 Range quadrant 1 Teat wrench for panoramic sight . . 1 Range-finding and fire-control equipment. 2 Aiming circle 1 Aiming-circle case 1 Aiming-Circle tripod Aiming-circle tripod case . 10 Battery commander's ruler, wooden . . On person or in store limber y 2 Battery commander's telescopes and mounts, model of 1915 . 2 Battery commander's telescope cases Accessories carried in case: 1 camel's-hair brush 1 on pack horse 1 pin wrench 1 in store limber 1 S3rew driver. 1 teat wrench 2 2 Battery commander's telescope tripods Battery commander'stelescope tripod cases. 1 2^for horse batteries. 2 For description of tire-control equipment see O. O. Form 1796. J Will be issued when available. 4 Metal B. C. rulers with cases are no longer part of the equipment. Those on hand may be retained. 196 Statement of total equipment of one 8-inch gun battery Continued. War foot- ing (4 guns, cais- sons) . Article. Where carried. classification. Class. Sec- tion. 2 5 16 i 1 1 2 3 37 319 56 1 6 1 1 12 6 5 s 20 20 8 8 6 20 6 4 6 4 12 8 4 4 6 6 6 6 2 6 4 6 6 6 6 6 6 6 2 6 Range-finding and fire-control equipment Continued. Chains for time-interval recorder [in store limber V [ IV IV IX IV IV i I i Flash lights with hoods Flash lights without hoods Where convenient On caisson in the fifth section [where convenient . Protractors xylonite rectangular Ruler for solution of triangles >On pack horse Range-flnder'case Range-finder tripod Oil caisson chest Reel for caisson Tape steel 100 feet [In store limber (Furnished by Signal Corps 2 ) >On horses Harness. Harness, lead, sets Harness, wheel, sets , Not carried in field Pack harness special pack equipment 4 Spare pxrts of Artillery harness. On pack horse In battery wagon Bridle Artillery off .do Bridle, Artillery, near ....do Cinchas lead ...do do .. Collar pads canvas Not part of harness Collar strap's .do Curb bits do Curb chains with hooks .do Feed ba^s In battery wagon Grain bags .do Halter headstalls do Halter tie ropes ....do Martingales with cincha strap do . do Side straps for breeching do ... do Stirrup straps .do Traces lead with chain do Traces wheel ...do Whips Artillery do ... Spare parts, of steel collars. Bolts for bottom of collar In miscellaneous spare-parts chest, store wagon. Carried loose Bolts for extension Bolts for top connection Bolts for trace plate Buckle latches Buckle springs Draft springs Pad bolts In miscellaneous spare-parts chest, store wagon. Carried loose Pad hooks, with collar back strap con- nection. Nuts for bottom bolt In miscellaneous spare-parts chest, store wagon. Nuts for extension bolt Nuts for top connection bolt ... Nuts for pa*d bolt Nuts for trace plate bolt Trace plate and loops Washers for trace plate bolt . . . 1 Fisld Artillery range finders will be issued as soon as a supply is available. When issued, the sextant talemeter now on hand in some of the organizations will be turned in. 2 For list of these parts see Unit Accountability Equipment Manual. 3 1 set is spare. This set of pack harness and special pack equipment will be issued to carry the fire-control equipment until the reel, 2 horse, is available. 197 Statement of total equipment of one 8-inch gun battery Continued. Article. Where carried. Property classification. Class. Sec- tion. Spare parts of breast collar harness. Bridles and bits, artillery Cinchas, artillery, lead Feed bags Grain bags . . t Halter headstalls Halter tie ropes, model of 1912. . Martingales, with cincha straps. Side straps for breeching Stirrup straps Traces, lead, with chains Traces, wheel Whips, artillery Breast collar with neck straps . . . Neck-yoke neck straps Choke straps Collar pads. Pad strap buckle pieces Cinchas, artillery, wheel Back strap hook Barrel roller buckles, 1.25 inches. Double eye loop Snap hook, convert's 2-inch Instruction equipment. Sectionaliz ed shell Sectionalized shrapnel Miscellaneous equipment. Reloading and cleaning outfit consisting of 1 bushing 1 cleaning brush (16.75 inches long) 1 case holder 1 case-holder stand 1 decapping tool (17.9 inches long) 1 hammer 1 primer-inserting press, small 1 saluting powder measure 1 storage chest Subcaliber and drill cartridge kit, con- sisting of 3 drill cartridges, 1 extra base 1 subcaliber cartridge 1 bristle cleaning brush 1 cleaning rod 2 closing cap set screws 1 extension piece 2 extractor springs 2 extractor-spring screws 1 eyepiece 1 graduated ring with felt washer 4 ring screws 6 rotating pins 6 stop pins 1 storage chest 1 wrench, pin Pistol-cleaning kit Arm racks for automatic pistols (For targets, see O. O. Pamphlet No. Ammunition. Shrapnel, H. E., rounds, or. Shrapnel, rounds, and Shell, rounds In battery wagon. In store wagon. |-Not carried in field. In chest for reloading and cleaning outfit in store wagon. In store. Where convenient. In ammunition chests. 198 Statement of total equipment of one S-inch gun lattery Continued. Article. Where carried. Class. Sec- tion. Personal equipment. See Unit Accountability Manual. Horse equipment for each horse. See U. E. A. M. Saddler's tools. Awl blades, harness, assorted Awl, pegging Awl. seat, handled Carriage, pricking, 3 wheels Compass, 6 inches Creaser, double, lignum vitae Claw tool Edge tool No. 1 Edge tool No. 2 Extra blades, with followers, for draw gage Gage, draw, brass Halts, patent, awl, rosewood Hammer, No. 3, riveting Handle, peg. awl, with wrench Knife, round Knife, splitting, 6-inch Needle case, leather , Needle, glovers' No. 3, paper Needles, harness No. 4, papers Needles, harness No. 5, papers Needles, harness No. 6, papers , Needles, sacking, assorted Nipper, cutting, 10-inch , Oilstone, unmounted , Pliers, 6-inch Punches, hand, round, assorted Punch, revolving Rivet sets Rule, boxwood, 2-foot, 4 fold Screw drivers, 3-inch blade Sewing palm, leather Shears, 10-inch bent trimmers Shoe knife, square point Shoe knife, broad point Slicker, steel Thimbles... Carpenter tools. Bench ax ' Bags, canvas, for small stores Bevel, 8-inch Bits, auger Bit, wood countersink Bit, expansive, 2 cutters Bits, screw driver Brace, ratchet, 10-inch sweep Chisels, socket, framing Dividers, wing, 10-inch Drills, twist File, 10-inch, flat, bastard Files, saw, 4 and 6 inch (3 of each) Gage, marking, brass, thumbscrew shoe and face. Gouges, socket firmer Hammer, claw, adze eye Handle, tool, containing 10 tools Handles, file, aluminum alloy Knife, drawing, 9-inch blade Mallet. 2J by 5 inches, maple, hickory handled. Nail set Oiler Oilstone, unmounted Pincer, small, 8-inch Plane, jack, wood Plane, smoothing, wood Plate, auger handle. Rasp, wood, 10-inch Reamer, half round, for wood or soft metal. Rule, boxwood, 2-foot, 4 fold In saddler's chest in battery wagon. In carpenter's chest hi battery wagon 199 Statement of total equipment of one 8-inch gun battery Continued. War foot- ing (4 guns, 12 cais- sons) Article. Where carried. Property Class. Sec- tion. 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 5 1 1 2 1 1 1 1 1 1 1 1 1 1 Saw Saw, Saw Screi Spot Squa Tape Vise Wrei Anvi Aprc Bags Box, Chis( Chise Chise Clinc File, Fire Fire Flatt Fore Forg Ham Ham Ham Hanc Hard Cutti Oiler Pritc Punc Punc Punc Punc Rive Rule Scre'v wn Shoe) Shoei Shoe] Sledg Squa Toel Tong Tong Tong Whel Wrer Wren Vise. Carpenter tools Continued, crosscut, 24-inch In carpenter's chest in battery wagon ?Tn forge limber chest X 9 rip, 24-inch set , iv driver, 5-inch blade 10-inch eshave, adjustable re, steel, 12-inch body, 8-inch tongue. . line linen table, 2i-inch ich, screw, 12-inch Blacksmith's tools. 1, 100-pound ns, blacksmith's , canvas, for nails. shoeing leather si, cold, 8-inch In forge limber chest 1, handled, for cold iron, 2 pounds... 1, handled, for hot iron, 1.5 pounds., hing iron flat, 12-inch, bastard . rake shovel . er, handled, 1.5-inch, square face punch and crease s, Empire, portable mer, hand, 2 pounds . mer, riveting, 1 pound 2 ounces mer, shoeing. 10 ounces lie, file aluminum ic, 0.75 square shank 1 25 bit ng nippers, 14-inch hel, 0.75 flats, 9-inch h, round, 0.375-inch h, round, 0.312 -^-uich h, nail h square t sets, 5 sizes boxwood, 2-foot, 4-fold. 7 plates, taps and dies, with tap men, including chest, ng knives. . ng pincers ng rasp, 16-inch. e, 11-pound re nife s, horseshoer's s for 0.25 iron s for 0.5 iron stone, farriers', 10-inch ... ch, forge ch, screw, 12-inch Horse bat- tery. Light bat- tery. Article. Where carried. Property classification. Class. Sec- tion. 5 1 1 3 3 5 1 1 3 3 Materials for cleaning and preservation (6 months' supply, all expendable). X 10 Black ' adhesive tape, f inch wid ^-pound roll. Brush camel's hair, No. 1 round e do Tn chest for oleanincr material and small stores. Brushes, sash! No. 5... ...do... 200 Statement of total equipment of one 3-inch gun battery Continued. Horse bat- tery. Light bat- tery. Article. Where carried. Property classification. Class. Sec- tion. 1 2 2 2 2 1 1 1 2 2 4 21 6 2 i? 25 20 1 5 6 1 15 20 5 5 2 75 75 5 6i i 7 6 75 1 1 1 72 6 100 100 10 8 40 5 6 1 i 2 2 2 2 1 1 1 2 2 3 21 6 2 7 25 15 1 5 6 1 15 20 5 5 2 75 75 5 5* 7 6 75 1 1 1 52 ^ 65 10 8 40 5 6 1 Materials for cleaning and preservation (6 months' supply, all expendable) Con. In store wason X X 10 9 Brushes varnish No 5-0 do . Brushes varnish No 6-0 do Burners, lantern, Tietz, Vesta Cloth, crocus, quires In chest for cleaning material and small stores. 1 quire in cleaning -material chest; the rest in store. In chest for cleaning material and small stores, do Cloth emery No J quire Cloth emery No quire Cloth, emery, No. 00, quire . . do Cosmic, No. 80, soft, quarts (1 quart cans) Chamois skins . In store wagon . In chest for cleaning material and small stores, do Pressing russet leather boxes Eveready tungsten battery No. 793 Eveready2 7 v Mazda bulb No 1197 In store wagon .... do Globes lantern In chest for cleaning material and small stores. In store wagon Lavaline, 16-ounce cans Lye, powdered, cans, 1-pound 5 pounds in store wagon; rest in store. Not carried in field Naphthaline pounds Oil, clock, ounce 1-ounce bottle In cleaning-material and small- stores chest. In cans on store limber Oil, hydroline, gallons. 5-gallon cans Oil, linseed, boiled, gallons 1 gallon in store wagon, rest to be retained in store at post. In cleaning-material and small- stores chest. In oil cans on battery and store wagons. 4 gallons in store wagon, rest to be retained in store at post. 2 gallons in store wagon, rest to be retained in store at post, lln oil cans under battery and f store wagons. 1 5 pounds in store wagon, rest to 1 be retained in store at post. Not carried in field Oil, linseed, raw, pints Oil, lubricating, gallons Oil neat's-foot gallons Oil, slushing light gallons Oil, coal, gallons Oil sperm gallons Paint, olive drab, second coat, pounds.. Paint, olive drab, third coat, pounds. . . Paint, rubberine, gallons (1 gallon cans). Petrolatum (vaseline), ounces (in tin box). Polish, Gibson's soap, 16-ounce cans Primer, brown enamel, quarts In cleaning-material and small- stores chest. In store wagon Sal soda, pounds, bulk 20 pounds in chest for cleaning material, rest to be retained in store at post. In cleaning-material and small- stores chest, do Sandpaper, No. 2J, quires Sandpaper No 14- quires Sandpaper, No. J, quires do Sandpaper No 00 quires do Soap castile, pounds In store wagon Soap H and H cakes or Paco do Soap, saddle, Frank Miller's, pounds (1-pound tins). Sponges, 5-inch do 25 in store wagon, rest to fce re- tained in store at post. In store wagon Sponges, large size, 5 or 6 inch Turpentine gallons gallon in store wagon, rest to be retained in store at post. 10 pounds in store wagon, rest to be retained in store at post. In cleaning-material and small- stores chest. Waste, cotton, pounds, white Wicks, lantern, size Saddler's material (6 months' supply, all expendable) Awl blades, harness, assorted Awl hafts, patent, No. 146, with wrench. Only one of these items will be issued to an organization. 201 Statement of total equipment of one 8-inch gun battery Continued. Horse Light Prop classin erty nation. bat- tery. bat- tery. Article. Class. Sec- tion. 3 8 21 6 40 12 12 3 12 12 8 2 8 13 5 30 6 9 2 10 10 7 Saddler's material (6 months' supply, all expendable) Continued. Buckles, bar, 1-inch Saalbach, bronze. . . Buckles, bar, tongueless, f-inch, brass.. Buckles, bar, tongueless, 1-inch, brass.. Buckles, bar, tongueless, lj-i ncn > brass. Buckles, centerbar, f-inch, bronze. Buckles, centerbar, f-inch, bronze. Buckles, centerbar, f-inch, bronze. Buckles, centerbar, 1-inch, bronze. Buckles, centerbar, 1 -inch, bronze Buckles, centerbar, If-inch, bronze Buckles roller f-inch bronze 2 2 15 15 Buckles roller f-inch bronze 4 4 n miscellaneous [ spare-parts 10 50 46 Buckles roller IJ-inch bronze chest, in battery wagon. 3 3 6 6 Buckles satchel J-inch bronze 6 3 3 1 Buckles wire f-inch 36 24 6 3 Cheek "D " bronze -.- 11 11 25 12 25 20 12 22 Duck, cotton' olive drab, 22-inch, No. 1. . . End buckle, 1-inch, bronze, with clip. - - End clip f-inch brass 30 12 End clip, 1-inch brass 30 21 End clip 1^-inch brass 12 9 Foot staples high, bronze I TY 24 18 Foot staples low bronze I 12 9 Foot staples, semicircular, bronze 8 8 Hooks, back strap MI ... IV 8 2 2 Hooks breast strap M I chest, in battery wagon. 6 10 Hooks, end, double (brass wire) / 1 g 12 Hooks, end single (brass wire) I 5 2 2 Hooks, side strap, wheel IV 8 6 4 Leathers, bridle sides \2 in store wagon, rest to be re- 1 V 6 5 Leathers, collar, backs / tained in store at post. } x 10 160 150 40 pounds in store wagon rest 1 1 Leathers, latigo, sides to be retained in store at post. In store wagon X 10 10 8 Nails, saddle 1 1 Needles, Glovers, No. 3, papers 1 1 In saddlers chest x 9 1 1 Needles, harness. No. 5, papers 1 1 Needles, harness, No. 6, papers 10 g Ornaments, brow band, copper 1 5 10 8 Ovals, saddle IX 5 5 3 Ovals, saddle bag 1 5 1 14 24 3 9 12 12 8 6 3 3 1 1 1 1 3 1 10 18 3 8 10 6 8 6 3 3 1 1 1 1 3 Pins, screw, brass, 1-inch, No. 2, 1 gross packages. Rings, |-inch diameter (rifte scabbard) . Rings, H inches diameter '(saddle) Rings, If inches diameter (back strap) . Rings, li inches diameter (breeching and throat strap). Rings, 2 inches diameter (halter) Rings, 4 inches diameter (chincha and quarter strap). Rings D, 0.85 by 1 inch (feed bag), M. I. Rings D, 1J inches by finch, with clasp, steel. Rings D, Ifrnches by 1 inch(with roller) . Rings D, 1.69 by 2 inches (with roller) . . Rivets and burrs, brass, f-inch, No. 12, pounds. Rivets and burrs, brass, |-inch, No. 10, pounds. Rivets and burrs, brass, f-inch, No. 10, pounds. Rivets and burrs, brass, 1-inch, No. 8, oval heads, pounds. Rollers lead rein steel In miscellaneous spare-parts chest, in battery wagon. X IX X 10 10 5 10 1,600 1 1,260 1 Rope, J-inch (halter), feet, manilahemp. Screws brass, 1-inch, No. 6, wood, 200 feet in battery wagon, rest in store at post." In battery wagon IV 8 15 10 gross. Sheep skins with wool on 4 in store wagon, rest in store x 10 at post. 202 Statement of total equipment of one 8-inch gun battery Continued. Horse bat- tery. Light bat- tery. Article. Where carried. Property classification. Class. Sec- tion. 2 2 4 5 2 2 3 3 6 8 36 2 8 3 6 1 1 1 1 2 2 2 20 35 15 20 2 2 12 4 2 6 4 5 7 1 1 3 3 2 2 2 5 5 8 28 2 8 3 5 1 1 1 1 1 1 2 16 28 11 14 2 2 1 12 4 2 6 4 5 7 Saddler's material (6 months' supply, all expendable) Continued. Shields saddle 11-inch In ^miscellaneous spare-parts chest, in battery wagon. }" In ''"miscellaneous spare-parts chest, in battery wagon. In saddler's chest . IX X IX } * IX X 5 10 Li 10 5 10 Shields, saddle, lU-inch Shields saddle 12-inch Snap hooks . canteen, Cavalry Snap hooks, converts, -inch, 1C. I. Snap hooks, converts, 1-inch, M. I. Snap hooks, German, |-inch, M. I . Snap hooks, sack, 1-inch Snap hooks, swivel, 1-inch, No. 16. Snap hooks, German, 1-inch, M.I. Squares, halter, bronze Strap loops, coupling, J-inch (for bridle). Strap loops, feed bags Stud hooh-s Studs, saddle bag Tacks, copper, No. 12, | lb., paper Tacks, copper, No. 20, | lb., paper Thimble, aluminum lined, steel. 2 inch. Thread, carpet, No. 18, olive- pound. Thread, shoe, No. 3, brown, poun( Thread, shoe, No. 10, brown, pouc Wax, stitching, brown, whiter, po Webbing, oilve-drab, cotton, h( f-inch, yards. Webbing, olive-drab, cotton, he 1-inch, yards. Webbing, olive-drab, halter, 1- yards. Webbing jute 3J-inch yards size Irab, Is... ds... unds. ;avy, '&vy, inch, In battery wagon For polo equipment. Buckles, wire, J-inch Buckles, wire, f -inch Buckles, wire, f-inch Buckles, wire, 1-inch Buckles, nickel plated, stirrup strap, If-inch. Buckle, nickel plated, girth, 1-inch Ring J-inch diameter In battery wagon Web, linen straining, 3J-inch, yarc Web, linen straining, 5-inch, yard s do No. Article. Where carried. Property classification. Class. Sec- tion. 3 5 10 3 3 3 3 2 5 12 10 2 1 1 4 3 4 2 12 Buck Buck Buck Buck Buck Buck Buck] Buck] Buck] Buck] Buckl Burnc Cheek Cham Qonw Dress Endt Globe eserve supplies for war service. 1 es, bar, tongueless, f-inch Insto Insto ...d( re X 10 es, bar, tongueless, 1-inch es, center bar f-inch es, center bar, f-inch es, center bar, f -inch es, center bar, 1^-inch es, center bar, 1 f-inch es, roller, jj-inch es, roller, |-inch es, roller l^-inch re es, wire, f-inch rs, lantern "D" ois skin ly loops 1-inch Hf f , russet leather uckles s, lantern... )... 1 No material will be drawn from this supply for making repairs and replacements except in sudden calls for field servica if necessary to replace missing items of the regular supplies. To avoid deterioration, all perishable articles should be replaced by similar ones received v/ith the regular 6 months' allowance. 203 Statement of total equipment of one <3-inch gun battery Continued. Prot classic >erty cation. Class. Sec- tion. 2 Reserve supplies for war service Contd. Hooks, back strap >In store IV 8 2 3 Hooks, collar strap In store IX 1 3 Hooks' end brass wire .do IX 5 2 Leather, bridle, backs 2 Leather, collar, backs >In store X 10 30 1 Leather, harness, pounds Leather latigo, side . 3 Nails saddle In store IX 5 1 Oil, clock, ounce 4 Oil, coal, gallons 4 Oil, hydroline, gallons 12 Oil lubricating gallons >In store . . ... X 10 16 Oil, neat's-foot, gallons 2 Oil, slushing light, gallons 1 Oil, sperm, gallons 3 Ornaments brow band In store IX 5 2 Rings, f-ineh diameter, saddle bag 8 Rings, IJ-inch diameter, saddle 4 Rings, 2-inch diameter, halter In store IV 8 3 3 3 1 Rings, 4-inch diameter, cincha strap Rings, 4-inch diameter, quarter strap Rings "D," 1-inch diameter, feed bag. .. Rivets and burs, brass -inch, No. 10, pound 1 Rivets and burs, brass f-inch, No. 10, [in store X 10 pound 18 Salsoda, pounds 2 Snap hook, haversack, 1-inch In store . . . IX 1 3 Snap hook, feed bag ... do IV 8 12 Squares haHer do IX 5 40 Poap, castile. pounds 3 Soap, H. and H., cakes or " Paco" In store x 10 60 25 Soap, saddle, Frank Miller's, pounds Sponges, 5-inch 2 Strap loops feed bag In store IV 8 2 Studs saddle bag do IX 5 1 Tacks, copper, 12-ounce, paper 1 Tacks, copper, 20-ounce, paper 1 1 Thread, carpet, No. 18, olive-drab, pound Thread, shoe, No. 3, brown, pound In store X 10 25 Thread, shoe, No. 10, brown, pound Waste, cotton, pounds 1 Wax stitching brown pound 2 Wicks, lantern Ammunition.' See general orders pertaining to annual allowance of ammunition. INDEX. A. Page. Accessories (for battery wagon), list of 193-194 Accessories (for caisson), list of 193 Accessories (for forge limber), list of 194 Accessories (for gun and carriage), list of 189 Accessories (for limber), list of 192 Accessories (for store limber), list of 195 Accessories (for store wagon), list of 194 Accuracy of fire 174-179 Adjusting instruments 174 Adjustment of sights and quadrants 169-174 Additional tests 173 Panoramic sight 170 Range quadrant 171 Front and rear sight 171 Verification of parallelism of lines of sight and axis of bore 172-173 Allowance of supplies 199-202 Ammunition, allowance of 48 Ammunition, blank 48 Charge for 49 Preparation 49-50 Precaution 50 Ammunition, fixed 34 Ammunition, list of 197 Ammunition, misfires and hangfires 51-52 Ammunition carrier, location 77 Ammunition carrier, to remove 84-85 Ammunition-chest connecting piece (for caisson) location 95 Ammunition-chest connecting piece (for limber) location ; 90 Anvil, location 199 Apron (for caisson), description 99-100 Apron (for carriage), description 75 Apron latch, to remove 83 Apron-latch body (for caisson), description 100 Apron-latch body (for carriage), description 75 Apron-latch bracket, location 75 Apron-latch lever (for caisson), description 100 Apron-latch lever (for carriage), location 64 Apron-latch plunger (for caisson), description 100 Apron-latch plunger (for carriage), location 64 Apron-latch spring (for caisson), description 100 Apron-latch spring (for carriage), location 64 Ax-head bracket (for caisson), location 95 Ax-head bracket (for forge limber), location 125 (205) 206 Page. Ax-head bracket (for limber), location 90 Axle (for caisson), description 96-97 Axle (for carriage) 78 Axle (for limber), description 90 Axle bearing, location 60 Axle blocks 134 Axle seat, description 76 Axle seat, to remove 76 Axle-seat arm, location 63 Axle-seat arm bracket, location 63 Axle-seat arm guard, location 63 Axle-seat arm support, location 63 Axle-seat bracket fastening, location 63 Axle-seat support, location 63 Azimuth pointer, location 74 Azimuth scale, location 74 B. Battery wagon, model of 1902 130-135 Body, description 132-135 Nomenclature 130-132 Weights, dimensions, etc 130 Battery wagon, model of 1902 Mi 139-144 Body, description 143-144 Nomenclature 140-143 Weights, dimensions, etc 139 Blacksmith's tools, list of 199 Blankets, olive drab 186 Block carrier (for model of 1902 gun), description 15 Block carrier (for models of 1904 and 1905 gun), description 23 Block latch, description. 23 Bore sights, location 172-173 Brake (for carriage), to adjust 84 Brake (for carriage), to assemble 84 Brake (for carriage), to remove 83 Brake beam (for caisson, battery wagon, and carriage), location 97, 132, 77 Brake beam, to dismount 83 Brake beam fulcrum, location .. 64 Brake beam guide (for battery wagon and caisson), location 130, 94 Brake-beam guide (for carriage), location 64 Brake-beam tubes, location 64 Brake-box bottom, function 64, 132 Brake brace, location 64, 132 Brake channel (for battery wagon), location 130 Brake channel (for caisson), description 97 Brake-chanr el support, location 99 Brake crank (for battery wagon and caisson), location 98, 132 Brake crank (for carriage), location 94 Brake crank, to dismount 83 Brake guard (for battery wagon), location 130 Brake lever (for battery wagon and caisson), location 98, 131 Brake lever (for carriage), location 77 Brake lever, to dismount 84 207 Page. Brake rod, location 77 Brake rod, to dismount 83 Brake-rod end, location 77 Brake-rod spring, location 77 Brake-rod spring cover, location 77 Brake-rod spring cover end, location 77 Brake-rod spring cover head, location 77 Brake segment (for battery wagon), location 131 Brake segment (for caisson), location 94 Brake segment (for carriage), location 64 Brake segment, to dismount 84 Brake-segment bracket (for caisson), location 94 Brake segment (for caisson), function 98 Brake segment (for battery wagon), location 131 Brake-segment rack (for caisson), location 98 Brake shaft (for battery wagon and caisson), location 94, 131 Brake shoe (for battery wagon, caisson, and carriage), location 131, 97, 77 Brake shoe, to dismount 84 Brake spring, description 77 Breast- collar harness: Description 149 Nomenclature 150-151 Breechblock (for model of 1902 gun), description 14-15 Breechblock (for models of 1904 and 1905 guns), description 23 Breech mechanism (for model of 1902 gun), action of 17 Breech mechanism (for model of 1902 gun), assembling and disassembling parts. 18-19 Breech mechanism (for model of 1902 gun), nomenclature 14 Breech mechanism (for models of 1904 and 1905 guns), action of 29 Breech mechanism (for models of 1904 and 1905 guns), to dismantle 30 Breech mechanism (for models of 1904 and 1905 guns), description 23 Bucket holder (for limber), description 92, C. Caisson, model of 1902: Description 96-101 Nomenclature 93-96 Weights, dimensions, etc 93, Caisson, model of 1916: Description 109-115 Nomenclature 107-109 Weights, dimensions, etc . 107 Caisson limber, model of 1916: Description 103-106- Nomenclature of parts 101-103 Weights, dimensions, etc 101 Carpenter's tools, list of ' m 198-199 Carpenter's chest, description 134 Carriage, action of 70-71 Carriage, general description 67-7& Carriage, nomenclature 60-66 Carriage, parts of, care in assembling and disassembling 78-85 Carriage, parts of, care and cleaning 85-87 Carriage, principal parts of 67 10261417 17 208 Page. Carriage, weights, dimensions, etc 60 Cartridge case, description 34-35 Cartridge case, blank ammunition, care of 50 Cartridge case, blank ammunition, description 49 Channel support, location 94 Chest body (for caisson), description 98, 113 Chest body (for forge limber), description . 127, 126, 129 Chest body (for limber), description 92, 105, 118 Chest for cleaning materials and small stores, location 134 Chest for spare sights, location 135 Chest front (for caisson), description 98 Chest front (for limber), description 92. 105, 118 Chest-front angle, location 95, ]08 Chest-front tees, location 95, 108 Chest-front reinforce, location 90 Chest rail (for caisson), description 99 Chest rail (for limber), description 91 Chest-rail connection, location 91 Chest stiffener, location 90 Cinchas 146,150 Cocking lever, description 16 Collars, spare parts for, list cf 196 Collars, steel, description 147 Collar-lifting device 149 Contents, list of - 5-8 Converted battery wagon, model of 1908: Description 138 Nomenclature of parts 135-137 Weights, dimensions, etc 135 Converted caisson, model of 1908: Description 123-124 Nomenclature of parts 119-123 Weights, dimensions, etc 119 Converted limber, model of 1908: Description 1 18-119 Nomenclature of parts 116-118 Weights, dimensions, etc 115 Converted forge limber, model of 1908: Description 129-130 Nomenclature of parts 127-129 Weights, dimensions, etc 127 Counter-recoil buffer, description 69 Counter-recoil buffer, to remove 82 C ounter-recoil spring, double, description 69 Counter-recoil spring, double, to assemble 79 Counter-recoil spring, double, to dismount 79 Counter-recoil spring, single, description C9 Counter-coil spring, single, to assemble 80 Counter-recoil spring, single, to dismount 79 Cradle, to dismount 83 Cradle body, description 67 Cradle brush, location 62 Cradle head, front, location 61 Cradle head, rear, location 61 209 Page. Cradle top plate, location 61 Cross brace (for battery wagon), location 130 Cross brace (for caisson), location 94 Cyclometer, description 144 Cyclometer, nomenclature 145 Cylinder, to assemble 79 Cylinder, care and cleaning 85 Cylinder, description 69 Cylinder, to dismount 78-79 Cylinder, to fill 80 Cylinder end, description 69 Cylinder-end stud, description 69 D. Diaphragm (for caisson), description 98, 113 Diaphragm (for limber), description 92 Diaphragm brace (for caisson), location 95 Diaphragm brace (for limber), location 90 Door (for caisson) , description 98, 113 Door (for limber) , description 92 Door angle, location 95 Door frame, location 90 Door handle, location 95 Door hinge (for caisson) , location 98 Door hinge (for limber) , location 89 Door lock, description 92 Door prop, location 95, 99 Door-prop guide, location 95, 99 Door-prop stud, location 95 ? 99 Door tees, location 95, 99 Double tree, description 91 Double-tree rod, location 88 Double-tree strap (for limber), location 88 Drill cartridge, description 48 Dust guard, description 76 E. Elevating and traversing lock, description 74-75 Elevating and traversing lug, location 74 Elevating bevel gear, to dismount 82-83 Elevating bevel gear, location 73 Elevating bevel pinion, to dismount 83 Elevating bevel pinion, location 63, 73 Elevating crank shaft, location 63, 73 Elevating-gear bracket, to dismount 83 Elevating-gear bracket, description 73 Elevating-gear transom, description 72 Elevating mechanism, to assemble 83 Elevating pin, location 63 Elevating screw, to dismount 82 Elevating-screw cover, function 73 Equipment, list of 11 Equipment, horse, list of 198 Equipment, instruction, list of 197 210 Page. Equipment, miscellaneous, list of 197 Equipment, personal, list of 198 Equipment, range finding and fire control, list of 195-196 Equipment for one 3-inch battery, statement of total 189-203 Equipment, target, list of . Error, range 175-177 Extractor (for model 1902 gun), description 16 Extractor (for models 1904 and 1905 guns ) , description 28 Extractor lever (for model 1902 gun), description 16 Extractor lever (for models 1904 and 1905 guns), description 28 F. Face plate, location 63 Firing handle, loca-tion (for carriages after No. 168) 71 Firing-handle bracket, location (for carriages after No. 168) 71 Firing-handle bracket seat, location (for carriages after No. 168) 71 Firing-handle hub, location (for carriages after No. 168) 71 Firing-handle return spring, function (for carriages after No. 188) 71 Firing handle with spring and plunger, location (for carriages Nos. 1 to 168). . . 71 Firing-lock case, description 26 Firing mechanism (for models 1904 and 1905 guns) 21-22 Firing mechanism (for models 1904 and 1905 guns), to dismantle 29-30 Firing mechanism (for carriages 1 to 188) , action of 71 Firing mechanism (for carriages after No. 188), action of 71 Firing pallet, description 28 Firing pin (for model 1902 gun), description 15-16 Firing pin (for models 1904 and 1905 guns ), description 24 Firing-pin spring, location Firing shaft (for carriages Nos. 1 to 168), description 71 Firing shaft (for carriages after No. 168), description 71 Firing-shaft bearing (for carriages Nos. 1 to 168), location 62 Firing-shaft return spring (for carriages after No. 168), function 71 Firing spring, description 25 Flask, description Float, description Foot rest (for caisson), description 99 Foot rest (for carriage), location 114 Foot rest (forge limber and limber), description 91, 125 Forge limber, model of 1902, general description 125, 126, 127 Forge limber, model of 1902, weights, dimensions, etc 124 Forge limber, model of 1902, nomenclature 124, 125 Forge limber, model of 1902Mi, description 127 Frame handle, location 94, 97 Frame reinforce plate, location 94 Front-sight bracket, location *- 66 Front-sight bracket support, location 61 Fuzes, F. A., combination 43-46 Fuze, Ehrhardt combination for high-explosive shrapnel: Action... 42 Description 40-41 Parts in 40 Fuze, F. A., combination, model of 1907M: Action 45 Description 43 Parts in.. 43 211 Page. Fuze setter, model of 1905M, general description 52-53 Fuze setter, bracket, model of 1905M: Description 53 Use 54 Fuze setter, hand, model of 1905M: Description 55 Use 55-56 Fuze setter, hand, model of 1912: Description 56-59 Use 58-59 Fuze-setter bracket, description 100 Fuze-setter latch body, location 100 Fuze-setter latch lever, location 96 Fuze-setter latch plunger, location 96 Fuze-setter latch spring, location 96 G. Gland, adjustment 81 Gland, location 62 Gun, model of 1902, description 13-14 Gun, model of 1902, care of 20 Gun, model of 1904, description 20-22 Gun, model of 1905, description / 22 Gun slide, location 61 Gun, to dismount 78 Gun, to mount 78 Gun, weights, dimensions, etc 13 H. Handrail (for caisson), location 95, 103, 120 Handrail (for forge limber), location 124 Handrail (for limber), description 93 Handspike, location 72 Handspike fastening, function 72 Harness, list of 196 Harness, artillery, nomenclature 145-146 Harness, spare, list of 196 Hatchet-blade bracket, location 90 Hinge pin, description 28 Hood, location 64 Hub band, location 66 Hub box, location 66 Hub cap, location 66 Hub cap, to remove 84 Hub latch, function 78 Hub liner, location 66 Hub liner, to remove 84 Hub ring, location 66 I. Inaccuracy, causes 174-175 Information, general, with reference to ordnance supplies , 181-186 Inner elevating screw, description 73 Instructions for care of materiel. . 184 212 L - Page. Lantern bracket (for limber), location 93 Lantern-bracket pad, location 192 Latch bolt, function 15 Leather, black, care of 151-152 Leather, russet, care of 151-152 Leather, reason for oiling 151 Lever latch, description 28 Lid (for forge limber), description 126 Lid hinge (for forge limber), location 124 Lid prop (for battery wagon), location 130 Lid prop (for forge limber), location 124 Lid-prop bracket, location 124 Lid-prop guide, location 124 Lid-prop plate, location 130 Limber, description 90, 103. 118 Limber, nomenclature 88, 101. 116 Limber, weights, dimensions, etc 88, 101, 115 Lock bar, description 98 Lock washer, function Lunette (for battery wagon, caisson, and carriage), description 133, 97, 72 Lunette bracket (for battery wagon and caisson), location 130, 94 Lunette bracket (for carriage), location 72 M. Main shield, description 75 Marking on ammunition packing boxes 46-47 Marking outfit 193 Material, cleaning and preserving, allowance for 6 months, list of 199-200 Material, saddler's, allowance for 6 months, list of 200-202 Materiel, suggestions for care and maintenance of 184 Middle brace, location 130 Middle rail, description 90 Middle-rail angle, description 97 Middle-rail plate, location 94 Misfires and hangfires 51-52 N. Name plate, description 72, 93, 101 National Guard, repairs for artillery issued to 183 Neck yoke, description 91 O. Oils for artillery materiel 182-183 Oil can, description 134 Oil-can cover, description 126 Oil-can support (for battery wagon), location 134 Oil-can support (for forge limber), location ] 26 Operating lever (for model 1902 gun), description 15 Operating lever (for models 1904 and 1905 guns), description 27 Operating lever -guide, function 15 Outer elevating screw, description 73 P. Padlocks and bolt snaps 145 Packing chests for spare breech mechanism, location 134 Packing, Garlock's 81 Painting artillery materiel 181 213 Page. Pallet shank, description 28- Panoramic sight, model of 1904: Care 168 Description 155-158- Use - 166-167 Panoramic sight, model of 1915: Care 168-169 Description 158-164 Use 166-167 Panoramic-sight case, description 75- Panoramic-sight case bracket, description 75- Paulina 192, 193, 194, 195- Pickpocket, chisel end , location 90 Pickpocket, needle end, location 89- Pintle (for caisson and limber), description 97, 91 Pintle (for carriage), function 67 Pintle bearing (for caisson and limber), description 91, 97 Pintle latch (for caisson and limber), description 91, 97 Pintle-latch spring (for caisson and limber), description 91, 97 Pintle socket, description 73-74 Piston, description 69 Piston rod, to remove 82" Piston-rod nut. location 69 Plates, list of 9 Pole, description 91 Pole clamp (for limber) , description 90-91 Pole prop bracket, location 91 Powder charge, composition of 36-37 Primer, general description 35-36- Primer, 110-grain percussion, action of 36 Primer, 110-grain percussion, description 35-36- Primer, saluting, care in service 36 Projectiles, description 37-39 Prop (for battery wagon), description 133- Prop (for caisson), description 97 Prop (for limber), location 91 T> Range quadrant: Care 169 Elevation-level holder, description 165- Quadrant body, description 164 Quadrant bracket, description 164 Quadrant rocker, description ] 64 Range disk, description 164 Use 166 Range quadrant case, location 75- Range quadrant case bracket, location 75- Range quadrant fastening, location 65- Range table: Service, for 3-inch field guns 31-32 Complete, for 3-inch field guns, models of 1902. 1904, and 1905, when fired with shrapnel 33-34 Rear clip, function 67 Rear-sight box bottom, location 72: 214 Page. Rear-sight box cover, location 72 Rear-sight bracket support, location 61 Rear-sight packing, function 72 Recoil indicator, location 62 Recoil indicator, to remove 78 Recoil-indicator guide, location 62 Recoil-indicator throw, location 62 Reloading and cleaning outfit, parts in 51 Reloading and cleaning outfit, use of parts in 51 Repairs for field artillery materiel 183-184 Retaining ring, location 67 Retaining-ring hasp, function 68 Rocker, description 73 Rocker, to dismount 85 S. "Saddler's tools, list of 198 : Saddler's chest, description 134 Saluting charges 49 'Saluting primer percussion, description 49 Sear (for model 1902 gun), location 16 Sear (for model 1904 and 1905 guns), description 25 Segment bracket, location 64 Semple tracer, description '. 39-40 Shell, common steel, description 37 'Shields, to remove 83 Shield brace, location 75 Shot bolt (for battery wagon), location 132 Shot bolt (for forge limber), location 124 Shot bolt (for limber), description 92 Shot -bolt bracket (for battery wagon), location 132 Shot-bolt bracket (for forge limber), location 124 Shot-bolt bracket (for limber), description 92 Shoulder guard, description 75 Shovel handle bracket, location 90 Shrapnel, common, description 38 Shrapnel, common, action of 38-39 Shrapnel, Ehrhardt high-explosive, action of 39 Shrapnel, Ehrhardt high-explosive, description 39 Shutter, open sight port, location Shutter, open sight port, description 7.5 Shutter, panoramic sight port, location 75 Shutter, panoramic sight port, description 75 Side rail (for battery wagon), location 130 Side rail (for caisson), description 97 Side rail (for limber), location 91 Sights, list of 195 Sights, bore 174 Sights, line, description 153 Sight, front, description 153 Sight, rear: Bracket support, description 153 Peep sight, description 154 Peep-sight deflection scale, description 155 Scroll gear, description 154 215 Sight, rear Continued. Page. Shank socket, description 154 Sight shank, description 154 Sight-shank range strip, description 154 Sights, care of front and rear 167-168- Singletree, description 91 Sledge holder, location 125 Spade, description 72 Spade edge, location 72 Spare parts (for caisson), list of .< 193 Spare parts (for carriage), list of 191-192 Spare parts (for model 1902 gun), list of 190- Spare parts (for models 1904 and 1905 guns), list of 190- Spare parts (for limber), list of 192; Spare parts, miscellaneous, list of 197 Spare parts of accessories, list of 195 Spare pole bracket, location 95 Spare pole fastening, location 95 Spare sights, lists of 195- Spare sights 174 Spare wheel fastening, location 132 Spare wheel support, location 132 Sponge fastening, location 72: Sponge staff socket, location 61 Spring centering tool, use of 79 Spring seat, description 15 Spring support, description 70 Spring-support guide, function 68 Step, location 91 Store limber, model of 1902, general description I 138 Store limber, model of 1902, weights, dimensions, etc 13& Store limber, model of 1902Mi, description 138- Store wagon, model of 1902, general description 139 Store wagon, model of 1902, weights, dimensions, etc 139 s Store wagon, model of 1902Mi, general description 143-144 Store wagon, model of 1902Mi, weights, dimensions, etc 139- Stuffing box, to pack. 81 Subcaliber cartridge, cal. .30, description 47 Subcaliber and drill cartridge kit, contents of 48 Supplies kept in reserve, list of 202-203 T. Tent, shelter 198 Testing level 171 Tie-rods (for carriage), location 76 Tie-rods (for limber), description 90 Tie-rod clamp, location 88 Tie-rod fastening, location 64 Tools (for battery wagon), list of 193-194 Tools (for caisson), list of 193 Tools (for forge limber), list of 194 Tools (for gun and carriage), list of 189 Tools (for limber), list of 192 Tools (for store limber), list of 195- Tools (for store wagon), list of 194. 216 Page. Tool-box bottom, location 72 Tool-box fastening, function 72 Tool-box top plate, location 72 Tool-box transom, location 72 Top plate, location 72 Top shield, description 75 Top-shield fastening, location 75 Trail, description 71-72 Trail, to dismount 85 Trail handle, location 71-72 Trail seat, function 71-72 Transportation by rail, method of loading a battery 187-188 Traversing-gear case, function 74 Traversing handwheel, function 74 Traversing link, description 74 Traversing-link pivot, function 74 Traversing lug, location 74 Traversing mechanism, to dismount 82 Traversing nut, description 74 Traversing plate, location 63 Traversing-plate liner, location 63 Traversing shaft, description 74 Traversing-shaft adjusting nut 74 Traversing-shaf t bearing, location 74 Trigger, function 16 Trigger arm, description 16 Trigger fork, description 25 Trigger shaft 26 Tube cover, location 77 Tube-cover latch, location ? 77 Tube head, location 63 Tube-support plate, location 76 V. Yise, location 133 W. Wheels, description 71 Wheel, to remove 84 Wheel fastening, description 71 Wheel fastening, to remove 84 Wheel guard, function 72 Wheel-guard transom, location 72 Wheel oil valve, function 71 Wheeled material, list of 189 WAR DEPARTMENT, OFFICE OF THE CHIEF OF ORDNANCE, Washington, June 5, 191V. August i, 1905. Revised May 10, 1908. Re vised July 17, 1908. Revised July 1, 1911. Re/ised October 1, 1912. Ke rised August 3, 1915. Re.ised June 5, 1917. FORM No. 1659. Ed. June 5-178,000. O YC 64309 UNIVERSITY OF CALIFORNIA LIBRARY