U F No. 1705 INSTRUCTIONS FOR MOUNTING, USING, AND CARING FOR MORTAR CARRIAGES MODEL OF 1 896 Ml AND MODEL OF 1 896 Mil FOR 12-INCH MORTARS MODEL OF 1890 Ml IRLF (TWELVE PLATES] APRIL 22, 1909 REVISED MARCH 18, 1913 REVISED JANUARY 11, 1916 ro o WASHINGTON GOVERNMENT PRINTING OFFICE 1917 GIFT OF So. 17O5 "ty.S. Oret*\ 9 ^ ce- i?(e|i". INSTRUCTIONS FOR MOUNTING, USING, AND CARING FOR MORTAR CARRIAGES MODEL OF 1 896 Ml AND MODEL OF 1896 Mil FOR 12-INCH MORTARS MODEL OF 1890 Ml (TWELVE PLATES} APRIL 22, 1909 REVISED MARCH 18, 1913 REVISED JANUARY 11, 1916 WASHINGTON GOVERNMENT PRINTING OFFICE 1917 WAR DEPARTMENT, OFFICE OF THE CHIEF OF ORDNANCE, Washington, January 11, 1916. This manual is published for the information and government of the Regular Army and Organized Militia of the United States. By order of the Secretary of War: WILLIAM CROZIER, Brigadier General, Chief of Ordnance . (3) 366527 TABLE OF CONTENTS. Page. Action of carriage 9 Adjustment of springs 23 Assembling the carriage 19 Azimuth circle 24 Azimuth circle and pointer 15 Base ring 10, 20 Care of the carriage general instructions 25 Cleaning recoil cylinders 26 Compression grease cups ^ 28 Counter-recoil springs 22 Counter-recoil springs and buffer stops 13 Distance rings and traversing rollers 21 Electrical attachments 16 Elevating gear 23 Elevating system 13 Elevation quadrant 15 Emplacement 9 Filling recoil cylinders 27 Floor plate, ladder, and dust guards 21 General description 9 General remarks 19 Important points 24 Implements 19 Lanyard attachment 16 Leveling ....-_ 20 List of plates 7 Oil holes ...., 28 Principal parts 10 Racer 21 Racer and side frames 10 Recoil cylinders 22 Recoil system 11 Removing packing from stuffing boxes 26 Service condition (lubrication, etc.) 27 Shot trucks and shot tongs 19 The carriage 9 To connect the piece with the recoil system 23 To dismount carriage for purpose of cleaning trunnions and springs 25 To lower the piece 23 To mount the mortar by blocking 22 To pack a stuffing box 27 To remove cradle and track 22 Top carriage 22 Tools and accessories and implements 19 Traversing mechanism 24 Traversing roller system 10 Traversing system 15 (5) LIST OF PLATES. MORTAR CARRIAGE, MODEL OF 1896 Mi. Drawing No . I . Emplacement 15-12K-2 II. General drawing 12-12-1 III. Elevating gear ; 15-12K-8 IV. Traversing gear 12-12-14 V. Recoil cylinder 12-12-18 VI. Shot truck. 15-12K-15 VII. Wiring diagram 12-12-21 MORTAR CARRIAGE, MODEL OF 1896 Mn. I. Emplacement , . . 15-12K-2 VIII. Longitudinal section 12-13-1 IX. Rear elevation ." 12-13-2 III. Elevating gear 15-12K-8 X. Traversing gear 12-13-8 XI . Recoil cylinder and guides 12-13-7 VI. Shot truck 15-12K-15 XII. Wiring diagram 12-13-11 (7) INSTRUCTIONS FOR MOUNTING, USING, AND CARING FOR MORTAR CAR- RIAGES, MODEL OF 1896 Mi AND MODEL OF 1896 Mn, FOR 12-INCH MORTARS, MODEL OF 1890 ML TWELVE PLATES. (The points in italics are of importance and should be specially noted.) GENERAL DESCRIPTION. NOTE. The general designs of the two mortar carriages, model of 1896 Mi and 1896 Mil, are very similar, the changes incorporated in the later model being mainly in the line of greater strength. The instructions below apply to both models of carriages unless otherwise indicated. THE EMPLACEMENT (Plate I). This emplacement is constructed of concrete, the loading platform of which is flush with the top surface of the floor plates of carriage when it is assembled. It con- tains a circular well 59.5 inches deep with steps on which the base ring is supported. The edge of the loading platform is not com- pleted until the angle irons which support the azimuth circle and floor plates have been located and their curved ends embedded in the concrete. The anchor bolts are also embedded in the concrete when the emplacement is constructed. THE CARRIAGE (Plate II). This carriage is designed to deliver an all-round high-angle fire of from 45 to 70 elevation. With the 1,046-pound projectile and full charge, the recoil is approximately 23 inches, measured on the piston rods. The horizontal piece when fully counter-recoiled is 54 inches above the loading platform, and the projectile, in loading, is wheeled directly into the breech recess, the tray of the ammunition trucks forming the loading tray. ACTION OF CARRIAGE. Upon firing, the piece and top carriage rotate to the rear and downward about the fulcrum pins, compressing 997717 2 (9) 10 the counter-recoil springs ai^d forcing the crossheads and pistons downward, until tlu- ^orabmed, resistance in the recoil cylinders and the springs stop the motion, after which the compressed counter-recoil springs immediately return the piece to the loading and firing height. The movement of the crank pin through the arc of a circle causes the recoil cylinders and guides to oscillate about their trunnions. PRINCIPAL PARTS. The carriage consists of the following principal parts, viz: Base ring and floor plates, traversing roller system, racer, side frames, top carriage, recoil system, counter-recoil springs and buffer stops, elevating gear, traversing gear, azimuth circle and pointer, elevation quadrant, lanyard attachment, electrical equip- ment, shot trucks, shot tongs, tools and accessories, and implements. BASE RING. The base ring is of cast iron, in one piece, and is secured in its position by twenty-four 1.75-inch anchor bolts. The outer flange of the base ring, 14 feet in diameter, which contains the bolt holes, rests upon the upper step of the well, whose surface is 24.5 inches below the floor level of the emplacement. The top surface is turned, forming the lower roller path and a vertical annular flange forms the male part of the pintle. The traversing rack is attached on the inside below the roller path, and its upper and lower surfaces are turned, forming the brake path. Eight brackets, rigidly supporting the azimuth circle castings, are bolted to the outer flange, these brackets and castings, together with radial angle irons whose outer ends are embedded in the con- crete, furnishing the support for the circle of cast-iron removable floor plates. There are 16 plates, retained in position by countersunk screws. TRAVERSING ROLLER SYSTEM. The racer rests and is traversed upon a circle of 24 live, conical, traversing rollers of forged steel, with a single flange. The rollers are 7.5 inches in maximum diameter, and their axes are held in the radial position by a wrought-iron (cast steel in some carriages) distance ring in six sections, in which their bronze-bushed journals have bearings. The distance ring has oil grooves finished around its top edges, reached through oil tubes in racer. RACER AND SIDE FRAMES. The racer of the model of 1896 Mi carriage is cast in one piece, 13 feet 9.5 inches in diameter. Its tower surface is turned, forming the upper roller path, corresponding to the lower roller path on the base ring. The outside annular flange extends downward, fitting over the pintle with 0.063 inch diametral clearance. It is a cellular structure, and upon its front edge are cast two lugs or brackets to which the top carriage is pivoted by means of steel fulcrum pins. On each side of the central opening are side frames running across to the racer from front to rear. These 11 side frames form the supporting bearings for the recoil cylinders and also for the fulcrum pins. Three removable oil plugs permit oiling the pintle and traversing rollers. Cast iron was originally specified as the material for the racer, and most of the carriages in service have racers of that material. As a result of the cracking of several of these racers, cast steel No. 2 is now specified, and all racers hereafter manufactured will be of this material. (NOTE. The cast-iron racers of carriages Nos. 104, 106, 116, 125, 148, 150, 151, 158, 165, 193, 209, 210, 237, 241, 243, 244, 260, 261, 262, 289, 294, and 300 have already been replaced by cast-steel racers.) A few of the cast-iron racers have been strengthened by the addi- tion of reinforcing plates of steel placed along the vertical sides of the central opening. The racer for the model of 1896 Mn carriage is cast with two longi- tudinal ribs, one on each side of the central opening. These ribs correspond to the side frames of the model of 1896 Mi carriage, reinforcing the racer and forming bearings for the cylinder trun- nions. All the racers of this model carriage are of cast steel No. 1. TOP CARRIAGE. The top carriage consists of two arms connected by a heavy web. The upper ends of these arms, form the trunnion beds in which the mortar is mounted. The top carriage is inclined to the rear at an angle of about 41, the lower ends being held by the fulcrum pins. Between the fulcrum and the trunnions are placed openings for the spring guide rods and the seat for the rocking counter-recoil spring cap. All model of 1896 Mi carriages, except Nos. 116, 125, 148, 149, 150, 160, 176, 204, 211, 216, 251, 254, 255, 260, 262, 283, 289, and all model of 1896 Mn carriages have the "Cast steel No. 2" top carriage shown on Plate I. The except ed carriages have steel-top carriages of an older pattern. RECOIL SYSTEM. The recoil is checked by two hydraulic cylinders provided with trunnions which oscillate in their beds on the side frames, their lower ends extending some distance below the racer. They are of cast steel, 7.78 inches interior diameter, and are fitted with 3.5-inch forged steel piston rods working through stuffing boxes at both ends of the cylinders. About the middle of the rod is screwed and pinned a bronze piston. The stuffing boxes each contain six rings of 0.625 inch square Garlock waterproof hydraulic packing. In the walls of each cylinder are cut three grooves, each 4.6892 inches in width and of varying depth, so as to give a constant pressure in the cylinders during the entire length of recoil. The energy of 12 recoil is taken up by the resistance which the fluid offers to being driven through these openings. NOTE. The by-pass channels and openings provided in model of 1896 Mi mortar carriages are not now used, all holes opening into the by-pass channels being plugged. (Plate V.) The cylin- ders of model of 1896 Mil carriages are cast without provision for by-pass channel and openings. The counter recoil is checked by a counter-recoil buffer. In the model of 1896 Mi carriages the upper face of each piston has an annular recess, which at the end of the counter recoil passes over the annular projection on buffer on the upper bronze cylinder head. The fluid thus imprisoned is able to escape by the clearances only, its resistance gradually checks the movement, and consequently the mortar returns gently to the firing position. In the model of 1896 Mil carriages the male part of the buffer is on the piston and the female part on the cylinder head, the principle being generally similar to that described above. The filling holes are now located about the middle of the cylinders in order to obtain a void, and the oil holes on the rear side of the cylinders near the upper ends are permanently closed and can not be opened. For all charges the cylinders should be filled to the level of the filling holes, removing for this purpose both plugs, so as to permit the air to escape. A neutral oil, of specific gravity of about 0.85 (such as the " Hydro- line" at present issued), is used, and with this oil the working pressure in the cylinders is about 5,000 pounds per square inch and the piston rod compression about 190,000 pounds. A denser oil would cause a higher pressure in the cylinders and therefore shorten the recoil slightly. If it is desired to measure the recoil, it can be done on one of the piston rods by making several turns around it with fine twine and tying it tightly just where the piston rod enters the stuffing box. The height of the twine above the stuffing box, after firing, will indi- cate the counter recoil, which will also be the recoil if the mortar has returned to the firing position. If it does not return to the firing position, the counter-recoil springs should be compressed. The lower ends of the hydraulic cylinders are connected by an equalizing pipe, in which is made up an emptying coupling, so that the resistance and the pressure in both cylinders shall be equal. The coupling is provided for emptying the cylinders at a convenient point. The emptying coupling was originally made of bronze. These are being replaced by steel couplings as becomes necessary. Bronze plugs are provided which can be used to replace the equal- izing pipes, thus continuing the piece in action after their injury. To the top of each cylinder are bolted two guides of cast steel, between which moves a sliding crossnead, into which the upper end of the piston rod is secured by means of a collar ar.d nut. The cross- heads are assembled over the crank pins, of forged steel, which are screwed into the trunnions of the mortar and held by spline screws. COUNTER-RECOIL SPRINGS AND BUFFER STOPS. The top carriage is supported at a point about one-third of its length from the fulcrum shaft by five columns of springs. Each column consists of five double-coil helical springs, threaded on a rod of forged steel. These five rods, arranged in a row side by side, serve to guide the springs laterally during recoil or counter recoil. They are also used to sus- tain the force of the springs when the mortar is dismounted tem- porarily the spring compressors assisting. For the latter purpose the spring-compressor washers are placed over the spring-compressor screws and the latter screwed into the ends of the rods (the plugs having been removed), after which the spring-compressor nuts are screwed down against the washers, until the crossheads are moved a short distance from the buffer plates. The lower ends of these spring columns rest in a spring box of cast iron and the upper ends bear against a spring cap. The spring box is hung, by means of trunnions, in two brackets of cast iron bolted to the under surface of the racer, which permit it to oscillate during recoil to the different inclinations of the spring columns. The spring cap, performing essentially the same office above as the spring box does below, is a thin rectangular steel casting fitting over the top of the spring columns, and having upon its upper surface a well-rounded knife-edge bearing. During recoil this bearing rocks in a groove running across the lower surface of the top carriage. Both the spring cap and box are perforated to allow the, ends of the spring rods to pass freely through them. As an additional precaution against shock when returning to the firing position, buffer stops are provided. These are made up of alternate layers of balata and steel plates, and are held between the guides under the caps. The crossheads moving between the guides during counter recoil strike these buffers when the mortar returns to the firing position, and are maintained in pressure contact under the guide caps by the counter-recoil springs. ELEVATING SYSTEM (Plate III). A circular rack of cast steel is bolted longitudinally to the mortar on the underside, so that the center from which its pitch line is struck is at the intersection of the axes of the trunnions and bore. This rack engages in a pinion of steel mounted on a heavy s'naft on the under surface of the top car- 14 r riage, which also carries an elevating gear to which motion is given this gear and shaft through intermediate gears by a second shaft extending across the upper face of the top carriage and bearing a handwheel at each end. The top carriage is cored out to permit the passage of the rack. The mortar is held hi the firing positions by means of a hand nut on the handwheel shaft, which locks that shaft by pressing the thrust collar against an adjoining bushing, which together form a conical friction clutch. To protect the teeth on the elevating gearing from injury which may be caused by inertia effects during the change of elevation in recoil, the elevating shaft carries a friction device. This device con- sists of alternate bronze and cast-iron disks working in a recess of the elevating gear. The bronze rings rotate with the elevating gear and the cast-iron rings with the elevating shaft by means of keys, but the keying does not prevent motion in the direction of the axis of the shaft. By means of a nut, plate, and coiled spring on the elevating shaft the rings are forced together and against the elevating gear, thus forcing the latter against a shoulder of a bushing which is rigidly fastened to the elevating shaft. The elevating gear is not fastened rigidly to the shaft or to the bushing, but with the nut and spring the pressure between them can be made great enough to prevent any slipping during elevating or depressing or an undue amount of slipping during recoil. This pressure will be properly regulated if the united effort of one man applied at each of the handwheels is just sufficient to cause a slipping when an attempt is made to depress below the minimum. More accurate adjustment should be made by regulating the friction by means of weights or a spring balance, so that slipping will occur with the mortar depressed against the stop when a force of 156 pounds is applied to the elevation handwheel shaft, at a dis- tance of 100 inches from the center of the shaft, in accordance with General Orders, No. 63, War Department, 1914. To hold the mortar in the horizontal position for loading and insure against accidental elevating when the breech is open, an elevation lock is provided. This consists of a lock bar and spring attached to the top carriage and engages a lock stud on the elevation rack, thus automatically locking the mortar when horizontal. To elevate the mortar, the lever which serves to withdraw the lock bolt must be operated and held open by hand until the mortar has moved suffi- ciently in elevation for the stud to clear the lock bar. On each side of the elevating rack is placed an auxiliary eleva- tion scale graduated in 10-minute intervals. Pointers attached on each side of the opening in the top carriage indicate the elevation of the mortar. 15 TRAVERSING SYSTEM (Plate IV). The circular traversing rack on the inside of the base ring has meshing with it a pinion on a vertical shaft which passes down through the racer and having at its upper end a worm wheel. Motion is given the latter by means of a hand- wheel mounted on a worm shaft. The worm shaft, worm wheel, and the part of the vertical shaft above the racer are incased in a standard, which has oil and drain holes so arranged that the worm and the gear rim run in oil. This standard is of cast iron for model of 1896 Mi carriages, and of cast steel for model of 1896 Mil carriages. The vertical traversing shaft is of cast steel for model of 1896 Mi carriages and of forged steel for model of 1896 Mn carriages. In order to maintain the piece without further movement until fired after having been set in azimuth, a traversing brake is applied. It consists of a toggle and coiled spring acting to cause a brake shoe to grip the traversing rack. The brake is operated from the top side of the racer near the azimuth pointer by two pedals a foot lever and a catch. Depressing the foot lever sufficiently to engage the catch raises the brake shoe from the brake path and permits free motion of the racer. Releasing the foot lever by depressing the catch throws the brake on. The brake should be so adjusted that one man working on the handwheel can with difficulty just traverse the carriage when the brake is on. AZIMUTH CIRCLE AND POINTER. A brass circular strip in eight sections, about 1 inch wide and graduated to degrees, is attached to the top side of the azimuth-circle castings which surround the racer. Attached to the racer is a small brass pointer or subscale. This pointer is subdivided to 0.05 and stamped in hundredths of a degree. An electric light is attached for illuminating the scales, and a cast-iron cover when closed down protects the subscale and the light. ELEVATION QUADRANT. To save time in bringing the mortar to the desired elevation and to avoid inaccuracy in placing the quadrant and holding it against its seat, a special elevation quadrant has been designed. This quadrant is similar to the gunner's quadrant, but permanently attached to the left rim base of the mortar, and con- sists of a bracket with a toothed arc and an arm hinged at the other end. The arm is telescoped and its front bushing carries a bubble, a micrometer, and a toothed sector which is constantly pressed out- ward by a spiral spring. The teeth of the sector engage in the teeth of the arc, which are cut in degrees from 45 to 75. The micrometer, which gives a limited movement to the arm, is graduated to a least reading of one minute. When the quadrant is set to the required 16 angle of elevation and the piece loaded, the mortar is given the proper elevation by bringing the bubble to the center of the tube. A canvas cover has been provided which should be kept on the quadrant when not in use. LANYARD ATTACHMENT. A short lanyard is attached to the underside of a stopper in the top of the racer in rear of its central opening and extends below a pulley on the pit ladder, thence up- ward to the safety lanyard device, and thence to the firing mech- anism. The safety lanyard device consists of a bridle clip fastened to the plug set in the face of the breech, and a ring fastened at such a distance from the hook end of the short lanyard that the hook of the lanyard and ring can be fastened to the firing mechanism and the bridle clip. While loading and laying the mortar the ring should be on the clip. A pull on the lanyard is resisted wholly by the bridle clip, which will not permit the ring to slip off and allow a pull on the firing mechanism until the mortar has attained an ele- vation of about 43. The long lanyard is hooked into the eye on the top of the stopper and the stopper and short lanyard drawn to the rear to fire. ELECTRICAL ATTACHMENTS. These consist of the firing circuit, its safety attachments, and the lighting circuits. FIRING CIRCUIT. The current for the firing circuit is operated by a hand-operated alternating-current magneto, type MA, located at the mortar pit. The magneto is attached to a bracket (77A) on the wall of the pit and connected with the Engineer plug box by a flexible cable 72 inches long. One end of the magneto cable is con- nected to the terminals (T97P and T97Q) of the magneto and the other end is connected to the cable plug (P73D) as furnished with plug box (E20B) by the Engineer Department. The magneto bracket (77A) is furnished by the Ordnance Department and is set up on foundation bolts installed by the Engineer Department. The conduits and wiring to each mortar well are furnished and installed by the Engineer Department in accordance with General Orders, No. 1, War Department, 1913. The engineer cable, type 1, termi- nates in a water-tight receptacle box (E25H1) bolted to the under- side of the base ring. When not actually in use this box is kept closed by means of a receptacle cap (E23J) and rendered water- tight by a rubber gasket. The connection between the fixed base ring and the rotating racer etc., is accomplished by means of slicked reinforced cord, No. 16 (inclosed twisted pair, each approximately 2,583 circular mils), new code Type P. W. P. To facilitate connecting up, the inlet end of this cord terminates in a plug (E25Z) which can be quickly inserted in the receptacle referred to above, the joint being closed by means 17 of a plug cap (E23AC) which is screwed directly to the receptacle cover, and rendered water-tight by means of a rubber gasket. From the inlet-receptacle box on the base ring the flexible cord is led verti- cally downward to the bottom of the well, thence beneath two hooks which keep it always below the spring box to a double pulley cen- trally located on a three-legged bracket which straddles the emplace- ment drain. From the pulley the flexible cord is led to the left side rib of the racer opening where it terminates in a receptacle box (E25J1). This receptacle box is similar to that previously men- tioned, but, instead of a screw cover, is provided with a spring cover which closes automatically whenever the safety firing plug is with- drawn, thereby preventing access of water to the interior of the receptacle. The plug (E25Z1) is cut away on one side so that it can be inserted in the receptacle box (E25H1) in only one way. This is necessary to prevent possible short-circuiting of the magneto when firing more than one mortar. The safety firing plug (E25AA1) is similar to that already described, except that it is not provided with a cap and gasket for making a water-tight joint when inserted in the receptacle. This is, however, unneccessary in this case, as the plug is only inserted when ready to fire, and is immediately and automatically withdrawn when the mor- tar is depressed after firing. From this plug another length of flexible cord, looped slack in order to let the plug chain take the strain, leads to the face of the breech, where one lea'd is grounded and the other fastened directly to the spring plunger of the circuit breaker. Eventu- ally it is intended to mount a small transformer on the face of the breech, in which case both leads will be brought within the trans- former casing through water-tight stuffing tubes, and connected to the primary coil of the transformer. The purpose of this transformer is to provide a break in the metallic circuit between the magneto and the primer, thereby minimizing to a great extent the possibility of premature firing due to accidental grounds or crosses between the firing and lighting circuits. For use with a single-wire primer one of the secondary leads of the transformer is grounded directly to the mortar and the other is led to an insulated contact piece which com- pletes the circuit with the corresponding part on the breechblock when the mortar is completely rotated to its locked position. The firing plug (E25AA1) is cut away on one side to insure its being inserted in the receptacle box (E25J1) in one way only, as explained in the case of the plug (E25Z1). LIGHTING CIRCUIT. Current for the lighting circuit is supplied by the Engineer Department from the emplacement mains, and is led 997717 3 18 into each well by Engineer cable, type 1, terminating in a water-tight receptacle (E25AB), as previously described for the firing circuit. The connection between the fixed base ring and rotating racer, etc., is accomplished in a manner similar to that for the firing circuit, except that the outlet end of the lighting circuit terminates in a plug (E25AD) similar to that in which the inlet end terminates. In con- necting up the lighting circuits this plug is inserted into a receptacle (E25AB) which is permanently screwed into a junction box (E21T) located at the left side of the racer opening. From this junction box radiate the circuits for the azimuth lamp, elevation quadrant lamp, and portable lamp. These circuits are made up of twin- conductor, lead-covered, steel-armored cable, each conductor of 4,110 circular mils cross section, both ends secured to their respective terminal points in a water-tight manner by the use of stuffing tubes (E21Z). The circuit for the azimuth lamp passes around the inside of the racer opening until it reaches the depression for the azimuth pointer, where the cable is connected up to a water-tight receptacle box (E22N) which supports the azimuth lamp and reflector (E12P2). The circuit for the quadrant lamp leads to the upper part of the left crosshead guide where the cable is connected to a quadrant lamp bracket (E22P), which supports the quadrant lamp and reflector. The circuit for the portable lamp passes to the rear and is connected to a portable lamp plug box (E20B). Plug box and portable lamp are furnished by the Engineer Department. SAFETY FEATURED. In order to prevent possible accidents due to the crossing of the firing and lighting circuits, the plugs (E25AD) and (E25Z) are made noninterchangeable, in that the firing plug can not be inserted by mistake in the lighting receptacle on the base ring. The insertion of the lighting plug in the firing receptacle would obviously cause no damage, but in order to prevent mistakes the words "Firing" and "Lighting" are cast in raised letters on the covers of the corresponding receptacles wherever used. In order to prevent accidents due to firing at too low an elevation, the safety firing plug is suspended from the breech of the mortar by a chain whose length is determined by trial as only sufficient to permit .contact to be made at elevations of 43 and above. Automatic (closing of the firing circuit at this point is omitted advisedly. CARE OF ELECTRICAL EQUIPMENT. The electrical equipment can be divided generally into two distinct classes the permanent, rugged, and expensive installation of armored cable and water-tight accesso- ries on the base ring and racer; and the less rugged and correspond- ingly inexpensive but easily replaceable flexible cord, which should be removed from the carriage and stored in a clean and dry place when not actually in use. In the second class are included the complete 19 firing circuit and that part of the lighting circuit between the inlet on the base ring and the junction box on the racer. Except in emergencies, the carriage should not he traversed more than 180 degrees to the right or left of a line perpendicular to the flexible conductors on the floor of the mortar well. SHOT TRUCKS AND SHOT TONGS. The shot trucks for this carriage are constructed so as to admit of passing the shell directly from the truck into the mortar. Each truck consists of a light rectangular framework of steel mounted on four rubber-tired wheels and carrying a pan, in which the shell lies horizontally and at the proper height for loading. This shell pan projects to the front and is designed to enter the breech of the mortar and to supply the place of the usual loading tray. Two straight wooden bars which slip into sockets on each side of the truck serve as handles, and the two rear wheels are swiveled to facilitate turning. A brake is attached for holding the truck firmly in position against the breech while loading or unloading. Shot tongs are also provided for placing the shot on the shot truck. One pair of tongs is provided for each trolley installed by the Engineer Corps and two pairs are kept in reserve by the district ordnance officer for each battery. TOOLS AND ACCESSORIES AND IMPLEMENTS. The carriage is equipped with the tools and accessories necessary for its assembling and care. These parts, together with the implements for the mortar, except those too large, are stored in an armament chest. ASSEMBLING THE CARRIAGE. IMPLEMENTS. The assembling requires machines and implements for mechanical maneuvers usually found at forts, such as shears, falls, blocking, jacks, sling chains, etc. GENERAL REMARKS. -The size of the carriage is such that it must be dismantled for shipment, so that when it arrives at its destination it has to be entirely assembled. In assembling the carriage, as in all machinery, no parts should be directly struck with a steel hammer or sledge. Soft-metal drifts or copper or lead hammers should he used. In unloading or handling the parts care should be exercised that the edge or finished surfaces do not become upset or burred. When two bearing surfaces are brought together it is especially necessary that both parts should be absolutely clean, smooth, and well lubricated. In mounting the carriage the top, bottom, and back of the cross- head, the buffer plates, and that part of the top carriage behind the guides will be painted before assembling. These parts are not accessi- ble after being mounted, and if not thus protected would rust badly. of the order in which i to its position over the When the holes in die ring by means off jacks. If it should be nectar mck by means off the lugs on the apart, putting a piece off soft wood Repeat due opentians off towering until the the bolts as nearbr central in the holes as off every platform boh there should be an an iron plate 6 inches long, 4 proper support, faablmg it to be easily leveled by and ako permit the grouting to become well parts off die level and an off die pfttdorm bolts and nuts should be canfuOy to see that they are not bmred and are free from rust. After tfcey are put in onler thoroughly oil die threads off both boils In sore-wing down the nuts on die platform bolts take at a time, so that no part off the and ^stneNedse ~ that die middle of die level is of the straightedge with the ; of contact on the straight^ always be reversed and the mean off the true reading. The done from the top off the pintle, if die stra^itedfee should be off die roler path, following around first in one dhcrtion and then in die other, level- die foundation bolts until no mgfr spots are property fevefcd and fixed in die place, poor under it a grafting of neat Portland that the part below the level of the embedded. FIE the spaces between the melted lead. DISTANCE RDTCS ASTD roller path and roft emery doth and then assemble the thk is done ran the that they ran freely and do : . :-i - vboh the ^*th *zimtb-drdr brackets to the ftmgt of the base ring, care being taken to see that they _JM, - "B .M.^ . a^ -:. . --.-_ _. ..- ..i. .. -- RACES. Before aasembfimi the racer the the pintle with keraeene oil and the spring box. with its brackets on it. inside the the position it wm finally oocupr. with the top the brackets no higher than the~floor lerel of the means of skids and rollers the place, seeing that its floor lerel of the qiring-box brackets and spring box. by to their proper position against the then bolt firmly to the lAtei by the feet of the^ brackets, tlf up. the spring box mthji^ racer is placed in position for lowering.)) Lower the roflers: this can best be done by means of three apart, care being taken to ktep'bfcekiBg under it ami to little at a time. When in place ran it aiuaad several tancs by to see that it runs freely and the pml Ir surfaces do not biadL **d dowel and bolt attached to the FUDOK PLATE, ,4>ead ladder to the inner surface of the fUn^r on the frimt of thr and its brace to the under surface of the floor plate m the rear. After this the dust guards, in four sectinoss can be bofted o the interior flange of the racer just in idt the naV path 22 RECOIL CYLINDERS. To prepare the cylinders for assembling, remove the guides and caps and then the crossheads, take out the top cylinder heads, remove the piston rods, and clean the cylinders thoroughly. Then coat the upper interior parts of the recoil cyl- inders and that part of the piston rods below the piston head, which will be above the level of the oil, with light slushing oil, to prevent the formation of rust in the space above the level of the oil in the cylinders. After oiling the parts, replace the piston rods and cyl- inder heads. Removal of the piston rods will necessitate reassembling and repacking the stuffing boxes. See "Care of the carriage." Now clean the trunnions of the cylinders and then lower the cylin- ders into their respective openings in the racer and side frames and bolt on the cap squares. TOP CARRIAGE. With the aid of rollers run the top carriage bot- tom side up to the front of the racer and set in the fulcrum pins and their keys and set screws. Using shears, gin, or jacks, raise the trunnion-bed end of the top carriage up past the vertical unit until it inclines well to the rear, when it should be braced preparatory to receiving the mortar. The cap squares should now be removed. COUNTER-RECOIL SPRINGS. To assemble the springs the center of the mortar trunnions should be about 5 feet 9 inches above the racer. Put five springs in the spring box and lower through them the spring rods with the locking and adjusting nuts down against the fixed nuts. Now assemble the springs and washers on the rods, four on each rod above washers, and with the aid of a tackle let fall to their approxi- mate position against a scantling which had previously been located. The spring cap should then be placed in position. To MOUNT THE MORTAR BY BLOCKING the following articles are required: Oak rollers 3 feet long; one cradle 18 feet long and 3 feet wide; two 12-inch timbers 26 feet long, and two of the same length as the crib work; a quantity of 2-inch, 6-inch, 8-inch, and 12-inch blocking, and three hydraulic jacks of 15-ton capacity. On the emplacement floor in front and rear of the racer make two parallel crib works of blocking longer than the width of the top carriage. They should be sufficiently high to allow the two long 12-inch timbers, now laid from one crib to the other, to clear the top carriage. The outer faces of these pieces should be within the planes of the inner faces of the trunnion beds: Build a runway in front of the carriage, so that the mortar on the cradle can be removed on the track just formed, and bring the trun- nions of the piece over their beds. Carefully chock the rollers. To REMOVE CRADLE AND TRACK. Insert a heavy block in breech of mortar, allowing it to project 1 foot outside. Place head of hydraulic jack under this block close to breech and its foot on the 23 cradle and raise sufficiently to pass a 12-inch timber between mortar and cradle at right angles to mortar, and block up each end on crib- work outside of cradle. The crosspiece must now clear the cradle. Repeat the operation at muzzle and chock the piece front and rear. Remove cradle, rollers, and track. To LOWER THE PIECE. Jack up the breech as above described, remove sufficient of the crib to allow a 4-inch drop, and lower the breech onto the cross timbers. Do same at muzzle, and continue until trunnions are in their beds. Then bolt on the cap squares. The clearance between crosshead guides and end of trunnion is small, so great care must be taken in lowering. Remove the braces supporting the top carriage and lower the mor- tar and top carriage against the springs, the top carriage rotating about the fulcrum. It will be necessary to guide, with a crowbar, the spring rods through the openings in the spring cap and top carriage. If the weight of the mortar and top carriage is insufficient to compress the springs enough to enter the piston rod nuts in the crosshead, the latter having previously been bolted to the crank pins, a tackle should be used to draw the mortar down. To CONNECT THE PIECE WITH THE RECOIL SYSTEM. Screw the piston rod nuts with great force into the crossheads, assemble the guides to the cylinders, embracing the crossheads, and bolt on the guide caps with their balata buffers. See that the guides and cross- heads are well cleaned and oiled before they are put in place. Connect the equalizing pipe with the recoil cylinders. ELEVATING GEAR. Slip the elevating rack through the hole, intended for it in the top carriage and bolt it securely to the mortar. Slide elevating shaft through its bearings, friction device, and ele- vating pinion, screwing up on the clutch spring, adjusting nut at the same time. Bolt elevating nut pin bracket to the underside of the top carriage. Slide elevating intermediate pin through its bearings and elevating intermediate gears and fasten with tap bolt. Place in position the idler pin and elevating idler gear fastening with tap bolt. Bolt in place the elevating handwheel shaft brackets and assemble in position handwheel shaft with handwheels and collars. ADJUSTMENT OF SPRINGS. After the mortar is in position it may be found that the springs have not been compressed sufficiently to hold the mortar in the firing position, and that there are open spaces between the crossheads and the caps on the crosshead guides. These spaces must be closed by an additional compression of springs. For this purpose the lock nuts on the five spring guide rods are loosened and the necessary compression given by the adjusting nuts, the spindles being held from turning by means of the fixed nuts immedi- ately over the loose springs. During the adjustment of the springs 24 the mortar should be occasionally jarred against the stop on the top carriage by means of the elevating handwheels. The elevation lock must be held unlocked when the mortar is jarred against the stop in order to prevent the breaking of the lock when the mortar rebounds from the stop. The proper compression is given when the springs will hold the crossheads in pressure contact under the guide caps. TRAVERSING MECHANISM. Thoroughly clean all the traversing mechanism preparatory to assembling, first detaching the parts which have been shipped assembled. Then put the worm and worm wheel in the pedestal brackets, engage the gears, and insert the worm shaft. Next put the vertical traversing shaft through the pedestal bracket from the lower end. Key the upper end of the shaft to the worm wheel, put on the washer and nut, and insert the split pin. Bolt the bracket for vertical traversing shaft to its pad on the underside of the racer. Support the traversing pinion in its place, engaging the rack, shrouded side up. Lower the assembled pedestal bracket, allowing the vertical shaft to enter its lower bearing and pinion. Bolt the pedestal bracket to its pad on the racer and attach the traversing handwheel. If necessary, turn the handwheel to adjust the keyway for the traversing pinion and secure the pinion with key, washer, and nut. Put on the cover. Attach traversing brake. AZIMUTH CIRCLE. The azimuth-circle castings should next be put in place, fitting the ends together as marked, care being taken to see that the inner edge of the circle is central with the racer and 83.5 inches radius, so that the clearance between it and the racer is the same all around. Then bolt on the angle-iron brackets to support the floor plates and level them up with the plates on them, the outer ends being blocked up. The outer point at which these angle brack- ets are supported temporarily must not be more than 22 inches from the racer or else the supports will interfere with the filling in of the emplacement with concrete, which is to form the sides of the mortar pit and hold the brackets rigid. IMPORTANT POINTS. After the carriage has been completely as- sembled and the mortar mounted, the following points should be noted, viz: 1. Traverse the carriage each way and elevate and depress the mortar, to see that they work freely. 2. Examine and clean out all oil holes, noting that they have oil plugs. 3. See that there is not a hard bearing between the rim bases of the mortar and the top carriage, between the crossheads and crank- pin shoulders, and between the cylinder rim bases and their bearings, as these conditions would indicate parts out of alignment. 4. See that the elevating rack is firmly attached, that the coun- ter-recoil springs maintain the mortar fully a in battery/ 7 and that 25 the elevation stop permits the piece to be depressed to horizontal position so that projectiles can be rammed without interference.. 5. See that the dust guard does not bind or rub on the traversing rack and that the inner edge of the azimuth-circle castings are concentric with the revolving racer. 6. Attach the elevation quadrant, using a clinometer supported by a rest in the muzzle of the piece while fitting it, to test its adjust- ment. With the piece set horizontal the leveling of the base ring can be tested by traversing to each 90 position and noting the reading of the clinometer. 7. Orient the mortar, add numbers to the degree marks on the azimuth circle, and adjust azimuth pointer to indicate correct azimuth. Muzzle at true south is in azimuth and numbers are placed around clockwise to include 359. 8. See that electrical connections have been properly made by trying the lights and the firing circuits. To DISMOUNT CARRIAGE FOR PURPOSE or CLEANING TRUNNIONS AND SPRINGS. Remove crosshead guides and guide caps and unscrew piston-rod nuts. Then with the aid of jacks, skids, and blocking raise the mortar, the carriage rotating about the fulcrum until the center of the trunnions is about 5 feet 9 inches above the racer. The spring cap, spring washers, and rods can then be removed. With the springs out the trunnion cap squares can be removed and the top carriage lowered sufficiently to clean the trunnions and their beds. The same operation in the reverse order should be followed when assembling. CARE OF THE CARRIAGE GENERAL INSTRUCTIONS. Carriages should be traversed from time to time through their entire movement, and left at a different azimuth each time. It is especially required that all parts of the carriages must be kept free from rust at all times. If this be allowed to accumulate its removal from all bearing parts, and especially piston rods, requires particular attention in order that clearances shall not be unduly increased. The use of sandpaper for this purpose is forbidden, and emery cloth No. 1, being coarse enough for any ordinary rusting, should be used, the rust being softened, if necessary, by coal oil. If any leakage occurs from the hydraulic recoil system, it should be immediately remedied, calling, if necessary, upon the district armament officer for the services of skilled labor. The repacking of stuffing boxes may be done when necessary by trained enlisted men under the supervision of an officer, but will preferably be done by skilled labor. 26 Before removing a cylinder head containing a stuffing box, or draw- ing a piston rod through a stuffing box, the pressure of the packing on the rod should be released by unscrewing the follower several turns. The vulcanized fiber or copper gaskets between cylinders and their heads should be in good condition and consequently should be replaced whenever necessary in order to prevent leakage. Recoil cylinders should be emptied at least every three months and thoroughly cleaned every six months. CLEANING RECOIL CYLINDERS. For this cleaning a plumber's hand force pump will be supplied to each Coast Artillery post, with about 10 feet of suction hose and 15 feet of discharge tube. It will be noted that in no case will it be necessary to remove the packing from the stuffing box -to clean the cylinders. In cleaning, the following order of operations may be followed : (a) Remove oil from cylinders and equalizing pipes. (6) Compress the counter-recoil springs by means of the assembling screws, so as to lower the mortar a few inches, remove the guides and caps and disconnect and remove the crossheads. (c) Unscrew the cylinder heads and carefully withdraw the piston rods out of the cylinders. Each part dismounted should be marked to insure its being assembled in its correct place. (d) Thoroughly clean the cylinders with coal oil forced from a hand pump into both ends of each cylinder. The plug in the emptying coupling should be removed and both branches of the equalizing pipe flushed out from their cylinder ends. Then wipe the interior of the cylinders dry with clean cotton waste and clean the piston rods and cylinder heads. 0) Replace the emptying coupling plug, assemble the piston rods, cylinder heads, crossheads, caps, and guides, exercising great care that none of the parts are burred or otherwise damaged. The cylin- der heads should be firmly screwed into place, care being taken that the packing ring is in good condition and properly placed. Screw the followers tight against the packing in the stuffing boxes. (/) All parts dismounted should be carefully inspected to ascertain that they have been properly assembled. REMOVING PACKING FROM STUFFING BOXES (using new extractor furnished by the Ordnance Department). Close the extractor around the piston rod and insert the locking pin. Turn the extractor to the left, with pressure on the packing, until the needles are firmly engaged in the packing. Draw the packing out, turning slowly to the left. In the case of a box with interior thread and if the ring is tight it should be unscrewed and not stripped out by the thread, because unless unscrewed it would catch upon and be injured by the thread. 27 Extractor bars are provided to be used for starting the packing from its seat and by inserting the toes of the bars in the rack teeth and prying over the edge of the box, being careful not to injure the thread. To PACK A STUFFING Box. To pack a stuffing box, after drawing the oil from the cylinders, remove the follower and with it the rings and all the packing in the box. Examine the old packing and dis- card all unfit for use. If any of the old packing is used, it should be put in after the new. In packing a stuffing box put on the piston rod one ring of 0.625- inch Oarlock's " waterproof hydraulic" packing, and force it well to the bottom of the stuffing box by a wooden stick and mallet. Treat each layer of packing in a similar manner, until the required amount, with the old on top when any of the latter is used, is inserted. Put the halves of the ring on the follower, enter them together in the box, and screw up the follower, being careful to note that the halves of the ring do not bind on the screw threads. No more force should be used on the spanner wrench than that of two men, and generally that of one man is sufficient. The addition of a pipe to the end of the spanner wrench should not be permitted. When the box is properly filled and the follower tightened there should be for the lower boxes not more than 1 inch of space between the flange of the follower and the piece into which the follower is screwed. For the upper boxes there should be not less than 24 inches between the followers and the piston-rod nuts. The follower should be tightened from time to time. If the fol- lower is screwed into the stuffing box too tightly, an unnecessary amount of friction will be produced on the piston rod. When the follower is screwed in until the flange strikes the box another ring of packing should be inserted. It is to be expected that a slight amount of oil will soak through and drip from boxes or carriages when not in use. Also, when tight- ening the followers, a slight amount of oil will squeeze out of the sat- urated packing. This oil should be caught and not allowed to render the carriage unsightly. FILLING RECOIL CYLINDERS. To fill the cylinders with oil, remove the two plugs, one in each cylinder. Pour clean neutral oil of specific gravity about 0.85 (such as the "hydroline" now issued to the service) into the hole of one cylinder until it flows out of the hole of the other. Allow any air that may be present to escape, then pour in more oil until the same is level with the filling holes. About 9.5 gallons are required. SERVICE CONDITION (LUBRICATION, ETC.). When the carriage is to be kept in readiness for service and is in daily or frequent use all bearing parts must be kept clean and lubricated. Special attention 28 should be given to the lubrication of trunnion bearings, crossheads and guides, rollers, pintle surfaces, elevating rack and gears, and traversing mechanism, including the teeth of all gears. The above parts should be lubricated at frequent intervals whether the carriage is maneuvered or not. When carriages are in use for daily drills a thorough lubrication twice each week should be sufficient for all but the most severely used parts. Proper lubricating and cleaning of the traversing rollers and their paths are essential to the free working of the carriage. When oiling the rollers or the pintle the carriage must be traversed in order to distribute the oil throughout the whole circumference. It will occasionally be necessary to examine the rollers, to see that the dust guards are in proper place and that the rollers themselves are clean. If they are found dirty they must be cleaned with kero- sene oil, but care must be taken to fill the bearings with synovial oil after the kerosene has been rubbed dry. Experience has shown that recoil cylinders should not remain empty, as in that case the interior walls soon become rusty. OIL HOLES. Oil holes, where provided, must be cleaned out fre- quently to keep them free from sand and grit and will habitually be kept closed by the screw plugs provided, except when in the act of oiling. Before oiling at any hole, wipe off carefully any dirt or grit near the opening that might be carried down into the bearing by the oil. COMPRESSION GREASE CUPS. Where compression grease cups are provided similar precautions against dirt or grit must be observed. In filling these cups do not fill the cup completely, but fill only to the bottom of the bevel at the top of the cup; if too full, the leather packing will become inverted and will not act effectively. In putting on the cap see that the leather-packed follower enters the cup with- out being caught, cut, or bent by the edge of the cup, or otherwise. Screw the cap down on the cup, using a wrench, if necessary, to secure sufficient power, until the spring rod projects about 0.25 inch above the top of the cap. Later, when the spring has recovered and has moved the follower forward, forcing the grease through the tube into the bearings,- which will be indicated by the spring rod being pulled into the cap until its nut touches or nearly touches the cap, it will again be necessary to screw up the cap on the cup until the spring is again compressed. When the cap is screwed nearly home and the spring rod does not project it is an indication that the cup should be refilled. For further information regarding paints, oils, cleaning material, and methods of using same see Ordnance Department pamphlet Form No. 1869. Annual allowances will also be found therein. See also Circular No. 29, War Department, 1910. Names of parts of 12-inch mortar carriages, model of 1896 Mi and model of 1896 Mn, their piece marks, location, and material of v:hich they are made. The parts are listed alphabetically under the following headings Carriage proper; the electrical equip- ment, including the firing circuits, ammunition truck; shot tongs; lanyard attachment; elevation quadrant; and grease cup. When referring to a part, always mention its piece mark, where given on the list. Br Brass. Bz Bronze. C Copper. C. I Cast iron. C. R. S Cold rolled steel. Cond Condensite or equal. C. S Cast steel. F.V.F Flexible vulcanized fiber. G. I Galvanized iron. G. S German silver. G . AY . H . P Garlock waterproof hydraulic packing. H. R Hard rubber. L Lead. M.I Malleable iron. P. Bz Phosphor bronze. S Steel. S. B , Sheet brass. S. C Sheet copper. S . R Sheet rubber. S. S Sheet steel. Sp. S Spring steel. V. A vulcanized asbestos. V. F Vulcanized fiber. W. I Wrought iron. 12-INCH MORTAR CARRIAGE, MODEL OF 1896 Ml. Piece mark. No. Name of part. Location. Material. Remarks. U45M U45N U45AA N18B 11E 11J 13EA N20G 11C 1 1 8 8 1 1 8 1 1 1 1 1 15 3 1 1 1 12 16 16 36 8 28 4 2 2 4 4 4 1 1 5 2 2 2 8 8 4 4 2 8 8 8 36 1 2 1 4 4 8 8 1 Adjusting plug In upper brake lever S Complete. In 8 sections. 0.75 by 3.5. 0.75 by 2. 0.75 by 1.75. 0.5 by 2. 0.75 by 3. 0.75 by 3. 1.25 by 3. 0.75 by 2.25. 0.5 by 1. 2 by 4.25. 1.5 by 4.5. 0.75 by 1.5. 0.75 bv 1.5. 1 by f.75. 1.375 by 2.625. 0.75 by 2.25. 0.75 by 2.25. 0.75 by 1.5. 0.75 by 1.5. 0.875 by 2.25. ' 0.625 by 1.125. 0.5 diameter. 2 by 11.5. Iby3. 0.375 bv 1.25. 0.625 by 2.25. 1.25 by 3.75. 0.375 by 1.75. 1.25 by 4.5. 1.25 by 4.75. 1 by 2.75. 1 by 3.6. 0.75 by 2. 0.625 by 5. 1 by 5.25. 1 by 4.5. 1.5 by 5. 1.25 by 6.25. In adjusting plug s Angle irons Under floor plate s do do s Armament chest With 4 carriages Oak. Azimuth circle On azimuth circle bracket.. On base ring On racer . 0.1... c.s S B Azimuth circle bracket.. Base ring On platform In armament chest C. I. No. 2. . s Bar screw driver do do S.... do do s Bolt, countersunk, with nuts, do Floor plate to an a le . Bz For pit ladder s do For pit ladder brace s .. do For quadrant bracket Floor plate to angle For traversing rack Bz Bz s Bolt (special) Bolt tap do Azimuth circle bracket to base ring. Azimuth circle to bracket.. s do s do s Bolt tap (special) For cap squares s B olt tap Side frames to racer s do For equalizing pipe bracket. For elevating shaft bushing . For lower brake lever stop. . s . do s... do s do For elevating rack s do .... Hand wheel shaft bracket, right. Handwheel shaft bracket, left. For elevating intermediate pin bracket. For idler pin s do s do s . do s.. do For elevating-lock bracket. . s do For elevating-lock strap.. s For drip pan s Bolt' tap For spring-box bracket s do s do Cover to pedestal s do For foot-lever bracket s do Bracxet to racer s . do For left-hand scale Q Bolt with nuts Azimuth circle sections.. s. . . do - ...do.... s do ... do s do Fnr distnnpp riny s. do ' For plp.vatinn lnrk- s do For equalising pipe bracket. For clutch-spring adjusting nut. For elevating intermediate pin bracket. .. ..do s do s do s. . do s... do Cylinders to guides Caps (13F) to guides s s ....do Box.. r or sorines C.I. No. 2.. 30 NaTnes of parts of 12-inch mortar carriages, model of 1896 Mi and model of 1896 Mil , their piece marks, location, and material of which they are made Continued. 12-INCH MORTAR CARRIAGE, MODEL OF 1896 Mi Continued. Piece mark. No 1 1 1 1 1 1 2 1 1 1 2 48 4 1 1 3 1 1 1 1 2 5 2 1 2 1 4 2 1 1 1 1 1 1 1 4 2 1 1 1 2 1 25 25 4 1 1 1 1 1 1 2 10 2 1 2 2 1 1 1 1 1 1 1 Name of part. Location. Material. Remarks. U44AB N18D N18E 11D 13K 13F 13S 13CA IIP 5A 6A 13G1 13H1 13Y2 13Z2 13X1 13V 13W U43L U43J TJ43AK U43AN U43F U43C Box wrench In armament chest F S For elevation lock. For vertical shaft. 2 right, 2 left. For elevating handwheel shaft. Do. For elevating shaft For vertical shaft. For handwheel shaft. 2 right, 2 left. 1 right, 1 left. For Mr carriage. For Mil carriage. No. 9, olive drab. 1 right, 1 left. In 6 sections. 2 and 2.5. 1.5 and 1.75. 1.25 and 1.375. 1 and 1.125. 0.625 and 0.75. 0.375 and 0.5. Bracket. C. S. No. 2. C I do Under racer ...do... C S do For elevation quadrant do Bz C S Bracket base Brake lever pins In bracket s Brake link Through racer s Brake link spring On brake link. . . . . . s Brake link lower pin Brake link upper pin In brake link s.... do s Brake shoes. C.S.No.l... Bz Bz Bushings On traversing rollers In side frames. Bushing (in halves) ...... Bushings In top carriage Bz do do Bz do do Bz Bushings (long) In elevating intermediate gears. ... do Bz Bushings (short) Bz Bushings In elevating handwheel shaft bracket (right). In elevating handwheel shaft bracket (left). In crossheads (13G1) (13H1) In washers, or spring guide rod. In spring box brackets In pedestal bracket do Bz .... do Bz do Special Bz... Bz do ...do Bz... Bz Bz do do Caps do On guides (13A) (13B) (13C) (13D). C.S.No.l... C S Cap squares On side frames C.S.No.2... C S No 9 do Catch In foot lever bracket do C.S s Catch pin Catch spring do s Catch spring plunger do Bz Clutch spring On elevating shaft do do Sp. S F S C.S . Clutch spring adjusting nut. Clutch spring plate Collar For pipe connection . . s ....do... On piston rod F.S . do On traversing handwheel shaft. On lock bar s do s... Collar nut .... On elevating handwheel shaft, do F.S ....do F.S. Core hole cover C I Counter recoil springs (outer). Counter recoil springs (inner). Covers On spring rod Sp. S... ....do On side frames ... Sp.S s Cover On pedestal bracket C S do For elevation quadrant Between guides Cotton duck. F.S.No.2 Crosshead ....do do F.S.No.2... Cylinder (right) . ... In. side frames .... C.S.No.2 Cylinder (left) do C.S.No.2... Bz.No.4.,.. F.S.No.3... F.S.No.3... Bz Cylinder heads In cylinder (13Y2) (13Z2) . . . do do Cylinder plugs (small) . . . Cvlinder plugs (large) Direction plate (clamp) . . Direction plate (elevate) . Direction plate (depress) . Distance ring. On hand nut. On elevating handwheel . Bz . . do Between racer and base ring With carriage Bz C.S Double wrench F.S do In armament chest F.S do .do F.S... do do . F.S do do F.S ....do do F.S 31 Names of parts of 12-inch mortar carriages, model of 1896 Mi and model of 1896 Mil, their piece marks, location, and material of which they are made Continued. 12-INCH MORTAR CARRIAGE. MODEL OF 1896 Mi Continued. Piece mark. No. Name of part. Location. Material. Remarks. N20E N20A sc 11B 5J N20H U46F1 N20J 13N1 13T1 4 2 2 2 2 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 Dowels For side frames S . In 4 sections. Right. For Mi car- riage. Left. For Mi car- riage. Complete, includ- ing handle. Do. For Mi carriage only. For Mil carriage only. Pinion and gear to- gether. For Mi carriages. In 2 parts. Used where needed. Do. For Mi carriage only. With 2 crown nuts. For model of 1896 Mil only. For model of 1896 Mi only. For model of 1896 Mn only. Do. Do. 2 large, 10 small. do For azimuth pointer S... .... do For right-hand scale (N20B) For left-hand scale (N20M). In pedestil bracket Br Br do Drain plugs do S In emptving coupling W I Drip pans For stuffing boxes S Dust guard (complete). . . Elevating gear Inside racer s On elevating shaft Bz.No. 4.... F S Elevating-gear bushing. . Elevating hand wheel shaft bracket. do do On top carriage C.I do C I Elevating hand wheel shaft pinion. Elevating handwheel (right). Elevating handwheel (left). Elevating hand wheel shaft. do On elevating handwheel shaft. On handwhee' shaft F. S. No. 2.. S .. . do.. s In top carriage F. S. No. 2.. F. S. No. 2.. ...do... Elevating idler gear ^^ idlpr r>in Bz No 4 Elevating intermediate gear. Elevating intermediate bracket, do On elevation intermediate pin. On top carriage F.S. No. 2.. C.I do C I Elevating intermediate pin. Elevating pinion In top carriage F.S. No. 3.. F.S. No. 2.. On elevating shaft Elevating rack On mortar C.S Elevating shaft In top carriage F. S. No. 3.. Elevation pointer (right) Elevation pointer (left). . Elevation stop On top carriage Bz do Bz .... do.. Bz. No. 3 Emptying coupling On equalizing pipe Under cylinders F.S. No. 2.. s Equalizing pipe Equalizing pipe bracket. . Filler piece do W I On racer s. do For elevation lock. . s... do I do s 1 1 2 16 1 4 4 1 1 1 5 5 1 2 2 2 2 2 2 2 4 2 12 2 ....do . Between scale (N20M) and elevating rack. In armament chest Bz Filling funnel c Filler pieces Between scale (N20M) and elevating rack. On floor plate Bz Bz Floor instruction plate... Floor plates On azimuth circle and angles. In armament chest C.I . . . File card Commercial. Bz Bz.No. 4... C. S. . . . Followers In cylinder heads (13X1). . . For pipe connection do Foot lever bracket In foot lever bracket do On racer C S Foot lever pin In foot lever bracket s Friction disk (inner) Friction disks (outer). On elevating shaft C. I do BZ.NO. 4.... C.I Friction filler piece On elevation handwheel shaft. In lever on elevation rack . . In top carriage Fulcrum bolts . s Fulcrum bushings Bz. No. 3.... Bz.No. 3.... do .... do Fulcrum pins In side frames F S do .... do F.S. No. 2.. F. S. No. 2 Fulcrum pin washer Fulcrum washers On fulcrum pins On top carriage Bz. No. 3... Gaskets For plugs (13P) F. V. F do For plugs (13U2) c do For plugs in cylinders (13Y2) (13Z2). ' Under cylinder heads (13X1). C do F. V.F 32 Names of parts of 12-inch mortar carnages, model of 1896 Mi and model of 1896 Mil, their piece marks, location, and material of which they are made Continued. 12-INCH MORTAR CARRIAGE, MODEL OF 1896, Mi Continued. Piece mark. No Name of part. Location. Material. Remarks. U55FA 1 Gland wrench In armament chest S... 1 Graduation strip On azimuth circle Rr In 8 sections 13A 13B 1 1 Guide, front (right) Guide, front (left) On cylinders (13Y2) On cylinders (13Z2) C.S. No. 1. C. S. No. 1 13C 13D 1 1 Guide, rear (right) Guide, rear (left) On cylinders (13 Y2) On cylinders (13Z2) C. S. No. 1. C. S. No. 1 1 Hand nut On eJevating handwheel S 1 Hinge . shaft. For azimuth pointer cover Bz. . ] Idler pin In top carriage F. S. No 2 8 Keys... In distance ring S... 9 do In fulcrum pin S For side frames ^ 4 do .. Under side frames. . . S... ^ .. . do In elevating gear S. Riveted in ~5 2 do In elevating intermediate s 4 do gears. In elevating shaft S. . S .... do In elevating handwheel s 1 do shaft. In traversing handwheel s 2 do shaft. In vertical traversing shaft s... N20M1 Left-hand scale On elevating rack Monel metal. UN Lever On bracket on top carriage F. S... 11M Lever pin For elevation lock 8 11R I ever rest .... do F. S... I id For azimuth pointer Bz U47S Lifting hooks In armament, chest. S... 13Q1 Liner (right) On crossheads (13Q1) Bz 13R1 Liner (left) On crossheads (13H1) Bz... 13J1 Liner. . . .. do On crosshead (13G1) (13H1) On spring guide rods . . . Bz Br... 11L Link For elevation lock S... 11F Lock bar In bracket on top carriage. . F. S. No. 3.. no F S No 3 Lower brake lever In bracket C.S. Lower brake-lever stop For traversing brake S.... Lower toggle lever On lower brake lever C. S. . . On traversing handwheel Bz Name plate (No 2) On top carriage Bz 13L 2 In cylinders (13Y2) (13Z2) Bz 13BA1 ? Nuts... In crossheads (13G1 ) (13H1 ) . F. S. No. 2.. 5 do For spring guide rods S 2.75 thick. 5 do ... do S..., 1.5 thick. 9 . . do On vertical traversing shaft. s 9 do For toggle pin s 1 do On upper toggle link r. s U46A 2 Oilers (half-pint) In armament chest s Commercial. U46B 1 Oilers (locomotive 1 do s Do. J quart). Oil pipe In racer Br For inside of dis- 5F 1 do ....do Br tance ring. For outside of dis- 5G 1 do do Br... tance ring. For pintle. 1 do In pedestal bracket Br CT7- 2 Bz 1 In racer Bz 5D 2 Oil-pipe strap On racer S Qop 9fi Bz Q3K 12 do Hz 13M 4 j Pad: ing rings On followers (13N1) On racer Bz r. s In halves. 13 JA 14 Pieces Under caps (13F) Balata Pact of buffer. Pins For bushings on top car- Bz 0.25 diamond 2 do riage. In elevating intermediate S driven. Driven. 4 do gears. do ... Bz... 0.25 by 0.625 driven. 4 do do Bz 0.25 by 0.75 driven. 3 do In elevating handwheel Bz 0.25 by 0.875 driven. do shaft bracket (right). Bz 0.25 by 1.25 driven. 9 do shaft bracket (left). For brake shoes . ... S do s 1 Pinion... On vertical traversing shaft. Bz 33 Names of parts of 12-inch mortar carriages, model of 1896 Mi and model of 1896 Mil, their piece marks, location, and material of which they are made Continued. 12-INCH MORTAR CARRIAGE, MODEL OF 189G Mr Continued. Piece mark. No. 2 2 1 1 1 2 12 2 4 3 4 1 1 1 1 24 2 3 1 24 32 2 2 72 144 4 11 2 32 30 2 1 3 2 2 2 2 2 16 2 12 4 1 2 15 2 4 2 1 1 1 2 15 1 1 2 2 1 1 1 1 1 Name of part. Location. j Material. Remarks. 13DA 13AA U43AM1 UK 13GA 13HA 13U2 13P 13 E 5H N20B TJ44GA 5B 13FA N18C N20L N18A 5E 5E N20D N20F U44T U44 W U44HA N18F Piston On piston rod (13AA) In cylinders (13Y2) (13Z2).. With carriage Bz. No. 4... F. S.No. 3.. 1 F. S Part of buffer. Do. To replace equaliz- ing pipe. 0.375 diamond. For keys. 0.5 by 1.125. 0.5 by 1.125. 0.25 by 0.68. 0.25 by 0.75. 0.25 by 0.75. 0.5 by 1.5. 0.5 by 1.25. 0.5 by 1.375. 1.375 by 2.625. 0.25 by 0.625. 0.375 by 0.75. 0.375 by 0.75. 0.25 by 0.375. 0.125 by 0.3. 0.25 by 0.5. 1.5 by 3. 625. For Mi carriage only. 1 right,! left. 4.'625. For lower follow- ers. For floor plate. For elevating pin- ion. For elevating hand wheel shaft pin- ion. For thrust collar. For collar nut. For collar on lock bar. Piston rod . Piston-rod wrench Pit ladder (complete) Pivot stud Under removable floor plate For elevation lock i W I s Plates Under caps (13F) s do do s Plugs In cylinders (13Y2) (13Z2). do Bz. No. 3... Bz do . Plugs (1 extra) In cylinder Bz Quadrants, gunners' Racer In armament chest On base ring C. S.No. 2... s Reinforce plate Under floor plate Removable floor plate. . . Right-hand scale On racer C I On elevating rack Monel metal . G.W.H.P.. s Rings packing In cylinder boxes Rivets For reinforce plate do In elevating gear . ... s Rod (for spanner wrench) Screws In armament chest S For bushings in side frames. For trunnion cap bushings . For azimuth pointer Bz do Bz... . . do Br Screws, countersunk .... do For floor instruction plate. . Bz... For graduation strip Bz do For traversing roller bush- ings. For core-hole cover (5A) For removable floor plate . . Bz do Bz S do do For elevation stop s do For liners (13J1) (13Q1) (13R1). For liners on spring guide rods. For bracket (N18D) For filler piece (N20H) . . . Br do Bz do Bz s do.. . do For hinge on azimuth pointer. For elevating rack s Screws, fillister head... do s For bracket base s Screws, headless In elevating intermediate gears. For oil-pipe strap (5D) s Screws, round head Bz do For oil-pipe bracket (5K) Bz do Cover to bushing Bz do For direction plate (clamp). For direction plate (elevate) (depress). For elevation pointer (N20E) (N20A). For catch pin Br do Br Br do Screw (special) Bz do For right-hand scale (N20B) On spring-guide rods Bz Separators s Set screws For 1 ulcrum pin s Shaft bracket washer Side frames . Under shaft bracket s Onracer In armament chest. . . C.S. No. 2.. F. S ... Spanner wrench do ; do F S do ' do C S Spline screws Forscrp.w CM1RA1 s Split pins In countersunk bolts s do On lock bar (11F) s do Fnr linV holt nf filAvafvirm g ....do do For stop pin s For fulcrum nin s do In taper pin s do do s do do s do do s do . . do g s 34 Names of parts of 12-inch mortar carriages, model of 1896 Mi and model of 1896 their piece marks, location, and material of which they are made Continued. 12-INCH MORTAR CARRIAGE, MODEL OF 1896 Mi Continued. Piece mark. No. Name of part. Location. Material. Remarks. 11A U47BL U47BM U47BN U43AL 11H N20C N20K U47BD U45AB U43Q 2 2 1 1 2 2 2 2 4 2 4 1 2 5 5 5 5 5 2 1 1 1 4 14 1 1 1 1 1 5 1 1 1 2 1 1 1 1 24 1 2 1 1 1 1 4 1 1 1 4 12 5 5 2 2 2 2 4 1 1 3 Split pins For fulcrum bolt g 1 right, Heft. 2.5 by 9.75. 2 by;8.625. For Mi carriage only. Complete, with handle. In halves, 1 right, 1 left. With nuts. For Mi carriage. For Mn carriage. 2 large, 10 small. Commercial. For screw driver. For filling plug. ...do... For vertical traversing shaft For taper pin, on traversing handwheel shaft. For upper togglelink g .... do g . .do g do For upper toggle pin g do For brake-link upper pin g do For brake-link lower pin . . . S do g . . do For brake-shoe pins g do For upper brake-lever stop . For brake-lever pins g do ... . g Spring Sp S Spring-box brackets Spring compressor (screws). Spring compressor (nuts). Springe ompressor (washers). Spring guide rods Under racer In armament chest C.I. No. 2... s do s do .-. C.I In counter-recoil springs. . . . In end of spring-guide rods . F. S. No. 2.. Bz Spring guide-rod plugs. . . Spring-rod wrench With carriage F S Spring washer On brake link S Stop pin For traversing brake g Strap On top carriage In top carriage F. S F. S. No. 3.. S Studs with nuts .... do . . For spring box bracket Taper pin In elevating pinion s do In elevating handwheel shaft pinion. In thrust collar s do g do g do In collar on lock bar g . . do In washer, or spring guide rod. In traversing handwheel. . . g .. do .. s..., do In collar on traversing hand- wheel shaft. On elevating handwheel shaft pinion. g Thrusrt collar F. S g Toggle pin g Top carriage On fulcrum pins C. S. No. 2.. Traversing handwheel shaft. Traversing handwheel. . . In pedestal bracket On traversing handwheel shaft. F. S C. S. No. 3.. C. I. No. 1... F S No. 3 In pedestal bracket ... F. S Trunnion cap bushing. . . In top carriage Bz. No. 3... C. S... In bracket Upper brake-lever stop do S C S c.s Vertical shaft bracket studs. Vertical traversing shaft . Washer In racer s F. S. .. On elevating handwheel shaft, do S do Bz... do F. V. F do For plugs in cylinders (13Y2) (13Z2). On spring guide rods . . . L do S... do do do On vertical traversing shaft. On toggle pin S s do s do Under right-hand scale (N20B). Under bolts (N20G) Bz do Bz Indur a t e d fiber. Bz. No. 2... g Water buckets Worm wheel On vertical traversing shaft . rln F. S g i 35 Names of ports of 12-inch mortar carriages, model of 1896 Mi and model of 1896 Mil, their piece marks, location, and material of which they are made -Continued. 12-INCH MORTAR CARRIAGE, MODEL OF 1896 Mil. [For other parts of Mil not listed here, see list of Mi parts:] Piece mark. No. Name of part. Location. Material. Remarks. j Angle (in 4 sections) On edge of racer S To protec./ azimuth ^ Bolts countersunk with Ladder to floor plate S. . circle. jO.75 by 2.125. 1 nuts, do Ladder to brace S... 0.75 by 1.875. 24 Bolts tap For traversing rack s 0.75 by 3. 16 do . Azimuth circle castings to s 0.75 by 2.5. ?*> ...do... bracket . For bushings in top carriage Bz... 0.5 by 1.125. 4 ... do For foot-lever bracket S... 0.625 by 1.75. 4 do Bracket to racer s 1 25 by 3 s Bolts, tap (special) For cap squares on racer s... 2 by 4.75. g Bolts with nuts Azimuth circle castings to s . 1 by 2 5. 4 Bushings (in halves) intermediate angles. In bearings on racer Bz.No. 3 2 right 2 left. 4 Cap squares On racer C.S.No.l... Do. 1 On traversing worm shaft S.. 1 Core-hole cover On racer. C I 12 diameter. ? Cylinder head In recoil cylinders. . . BZ.NO. 4 1 Oil pipe In pedestal . Br 4 Oil tubes (bent) . In racer . . . Br... s Oil tubes (straight) .... do Br 1 Pedestal On racer C I 1 Pedestal cover. On pedestal C.I 9 Pistons On piston rods F S No 3 2 1 Piston bushings Pit ladder (complete) do Under removable floor plate Bz.No.4.... F. S 1 Racer On base ring C S No 1 ? Recoil cylinders In bearings on racer C.S.No 3 1 right 1 left. 1 Removable floor plate On racer C I 4 Screws, countersunk . . Core-hole cover to racer Bz 0.5 by 1.5. 11 .. . do Floor plate to racer Bz 75 by 2 I 9 do In racer oil holes Bz 5 by 1 80 Screws, countersunk Angle to racer s ?4 (special). Screws ("special) . For bushings in racer Bz Split pin In taper pin s Taper pin.. .. In traversing pinion.. s Traversing hand wheel . . . Traversing pinion . On traversing worm shaft . . On vertical traversing shaft C.I. No. 2... Bz. 2. Complete, includ- ing handle. Traversing rack On base ring F. S... In 6 sections. Traversing worm shaft . . . In pedestal S Vertical traversing shaft . do . F S No 1 ELECTRICAL EQUIPMENT. [On drawings 12-12-21 and 12-13-11, Plates VII and XII, are given the locations of the receptacles, plugs, etc., on the carriages and the lengths of slicked reinforced cord and armored cable required. In ordering parts for replacement, the piece mark given in the left-hand column and the name of the part should be stated.] E25M1 E25M1 E25M1 E25M1 E22L E21F E21J E22V T95C P57AE P57AF T96H T95J E22R 1 1 1 1 1 1 1 1 1 1 1 1 4 2 2 Base For receptacle, E25AB For receptacle, E25J1 For receptacle E25H1 Cond Cond For 110-volt main. For 220-volt main. For magneto, M. A. Furnished by En- gineer Depart- ment. For 1896 Mi only. 0.75 by 1.625. do.... do Cond do For receptacle' E25AF For junction box, E22N . . . . For junction box E21T Cond Cond do do Cond do .. . For junction box' E21U Cond do For quadrant lamp bracket, In bottom of well Cond Base bracket F S Boat snap hook On mortar Comm . . . s Boat snap hook screw Body do For terminal tube T96EA Bz Bolts, foundation, -with washers and nuts. Bolts, hex For magneto bracket For receptacle bracket, T95F. For quadrant lamp bracket, E22P. Bz Bolts, tap... g Names of parts of 12-inch mortar carnages, model of ,1896 Mi and model of 1896 J///, their piece marks, location, and material of which they are made Continued. ELECTRICAL EQUIPMENT Continued. Piece mark. No. Name of part. Location. Material. Remarks. T95D 3 Bolts, tap For base bracket S 0.75 by 8; 6 std. E20C 9 do For plug box s nuts. 25 by 875 T91R T91R 15 9 do do For straps, T91F For straps T91Z s s For 1896 Ml only. 0.5 by 1. For 1896 Mn only T91R q .... do For straps, T91F s 0.5 by 1. For 1896 Mil only E22Q 1 Bracket For quadrant lamp bracket Bz 0.5 by 1. V23AM 1 Bushing E22P. On plug box . . . Comm. 0.75 by 0.5. E25\J 1 do For cover for receptacle Cond E25AJ 1 do . E25J1. For receptacle, E25H1 Cond. T97P 1 Cable terminal For magneto cable T97Q 1 do do E12X ?, Cable thimbles For slicked cord . G.I. E13\J2 1 Candelabra receptacle For quadrant lamp V. A E13AJ2 1 do ' r ~ For azimuth lamp V A E12NA ? Candelabra lamps 8C P For elevation quadrant and Comm E23L Chain azimuth pointer. For receptacle E25AF Br. . No. 2, plumber's. E23L 1 ... do For receptacle E25H1 Br Do E23L 1 do. For receptacle, E25AB Br... Do. E23K 1 Chain pivot do Br E23K 1 do... For receptacle, E25AF Br... E23K 1 do . For receptacle E25H1 Br... E22Y 9 Connector links For quadrant lamp bracket S.C E21K 9 Connector strips For junction box E21T S. C. E25K1 9 .. .do For receptacle E25I1 S.C E25K1 ? do For receptacle' E25AB S.C... E25K1 9 do For receptacle E25AF S.C. E21L 1 do For junction box E21TJ s c E21N ? do do... S.C. E21M 9 ... .do For junction box E21T S.C E25S3 Contact housing For plug, E25AA1 Bz... E25T3 1 do For plug E25Z1 Bz E25T3 9 do For plug E25AD Bz E25Q 4 Contact screws rd hd do... Br.... 0.138 by 0.125 A. S. E25Q 2 ...do. For plug, E25AA1 Br... M.E.std. Do. E25Q 9, do For plug E25Z1 Br.. Do. E25P1 4 Contact strips For plug E25AD C... E25P1 ? do For plug E25Z1 C.... E25P1 2 .. -do For plug E25AA1 C.... E25R2 E25R2 Contact terminal... do do For plug E25Z1 Cond Cond.. G25AC1 do For plug E25AD Cond. E22AB Coupling For quadrant lamp Bz... E22AB - . . -do For azimuth lamp Bz E25G Cover For receptacle E25AB Bz E25G do For receptacle' E25AF Bz E25E1 do For receptacle E25H1 Bz E22S do S. B E21D 1 do E22P. For junction boxes E21T Bz P65A2 1 do orE21U. For cover for receptacle Bz E22C 1 ... .do E25J1. For junction box E22N... S. B 1 Expansion hook In bottom of well Comm 0.375 by 6. 1 do do Comm 0.375 by 3.5. T95E 1 Evebolt F S. E22E 1 Gasket For junction box, E22N S. R 0.062 thick. E23 \D 1 do S. R Do. E23AD 2 do For plug' E25A.D S R Do. E25D 1 do Forrecep'tacle E25AB S.R Do. E25D 1 ... .do For receptacle E25J1 S. R Do. E25D 1 do For receptacle E25H1 S.R... Do. E25D 1 do For receptacle, E25AF S.R Do. E23M 1 do do S. R Do. E23M 1 do For receptacle E25H1 S. R Do. E23M 1 .do For receptacle, E25AB S.R Do. E22U 1 do For quadrant lamp bracket, S.R Do. E22P. 37 Names of parts of 12-inch mortar carriages, model of 1896 Mi and model of 1896 Mn, their piece marks location, and material of which they are made Continued. ELECTRICAL EQUIPMENT Continued. Piece mark. No. Name of part. Location. Materia 1. Remarks. E21C 1 Gasket For junction box, E21T or S. R 0.062 thick. E23AB1 l Gland E21U. For receptacle E25J1 Bz E25 YB1 2 do For plug E25AD . Bz E23AB1 1 do For plug, E25AA1 BK..: E23A.B1 1 do For plug E25Z1 Bz E22.T 1 do For junction box, E22N . . . Bz E21Y1 5 do For terminal tube E21Z Bz E25W 9 do For terminal tube, E25AE Bz T96GA 1 Gland nut For terminal tube, T96EA . Bz For magneto, M. A E25V > Gland rings For terminal tube, E25AE Bz T96FA 1 do For terminal tube, T96EA . Bz.... Do. E21X -, do For terminal tube, E21Z . Bz E25U 4 For plug E25AD Br E25U 9 do For plug, E25AA1 Br E25U 2 do For plug E25Z1 Br E21A1 1 Junction box For junction box, E21T or Bz E22X 1 Lamp fit-tin 01 E21U. For ouadrant lamp Bi E22A1 1 Lamp junction box For junction box, E22N Bz For azimuth lamp. E12Q1 1 Lamp spring For azimuth lamp P Bz . E12Q1 1 .... do For ouadrant lamp P. Bz P65C1 1 Lid For cover for recaptacle Bz 1 Magneto type M V E25J1. Attached to magneto P73D 1 Magneto cable plug bracket. For magneto cable Furnishedjby~ En- 77 A 1 Magneto bracket Attached to wall of em- gineer Depart- ment. E25N1 1 Mica placemnt. For receptacle E25VB 0.1875 by 2 by 0.062 E25N1 1 do For rcc3ptacle E25I1 thick. Do. E25N1 1 do For receptacl 3 E25H1 Do. E25N1 1 do For rec^ptacl^ E25 VE Do. E21H 1 do For junction box E21T or 3.5 diameter by E22BA 1 do E21U. For junction box E22N 0.031 thick. 1.375 bv 1.375 by E22CA 1 do For ouadrant lamp bracket 0.062 thick. 1.625 bv 2.375 by E25AM 4 Nuts, hex E22P. For receptacle, E25AF Bz "... 0.062 thick. 0.190 bv 0.2 thick, E25\M 4 do For receptacl E25 \ 15 Bz 0.375 flats. Do. E25AM 4 do For receptacle, E25H1 Bz Do. E25\M 1 do For receptacle E25J1 Bz Do. E22G 4 .... do For ouadrantlamp bracket Br 0.190 by 0.125 high. E22G 4 ...do E22P. For junction box E22N Br.. Do. 2 . . do On plug chain Br Do. E21S 16 do For junction box E21T or Br Do. T95K 2 Nuts, wing E21U. For receptacle bracket Bz For 1S96 Mi only, 1 Packing T95F. For terminal tube E25AE Flax 0.375 std. 5 do For terminal tub^ E21Z Flax Square Navy type. 1 do For receptacle E25J1 Flax Do. E22K 1 ...do For junction box, E22N Flax... Do. E25AK 1 Pin For cover for receptacle H. R . E25AK 1 ... do E25J1. For receptacle, E25H1 H. R E20B Plug box On side frame 1896 Mi on Furnished bylEn- E23AC1 2 Plug caps racer, 1896 Mn. For plug, E25AD Bz... gineer & Depart- ment. E23AC1 1 do For plug, E25Z1 Bz . E21E 1 Plumber's chain For junction box E21T or Br 5 long. E20A 1 Portable lamp and cable. E21U. For plug box, E20B FurnishedJbvlEn- 1 Pulley block double For base bracket Comm gineer Depart- ment. 0.375 by 1.25 sheave E25A 1 Receptacle box For receptacle E25AB Bz swivel eye. E25B1 1 do For receptacle E25J1 Bz E25A 1 do For receptacle, E25Hi Bz E25AG 1 ...do... For receptacle, E2.">.\ F. . . Bz... 38 Name* of parts of 12-inch mortar carriages, model of 1896. Mi and model of 1896 J///, their piece marks, location, and material of which they are made Continued. ELECTRICAL EQUIPMENT Continued. Piece mark. No. Name of part. Location. Material. Remarks. E25G 1 Receptacle bracket For receptacle bracket, Bz For 1896 Mi only E23J 1 Receptacle cap T95F. For receptacle, E25J1 Bz... E23J 1 do For receptacle E25H1 Bz E23J 1 do For receptacle E25AF Bz E23J 1 do For receptacle E25AB Bz . E12P3 1 Reflector For azimuth lamp S B E12P3 i do For quadrant lamp S. B P65F 1 Ring . ~~ On plug chain Corn rn Galvanized 1 Sash chain For receptacle stud T95V Br. . For 1896 Mil only .. . do On boat snap hook Comm 4 inches of 0.187 chain. Brass No 3 E22B 2 Screws, fil. hd For junction box E22N.. . S 0.375 by 1 std. T95H ? do For receptacle bracket Bz For 1896 Mi only E25C 9, .. do T95F. For receptacle E25H1 S 0.5 by 1.125 std. 0.375 by 875 std E25C 7, do For receptacle E25AB s Do E25F 8 Screws flat fil hd For receptacle' E25J1 Br 0.164 by 0.45 A. S. E25F 9, .. do For receptacle E25AB base Br M. E.std. Do. E25F 4 do For receptacle E25H1 cover Br Do E25F ?, do For receptacle E25AF base Br Do. E25F 9, do For receptacle E25H1 base Br Do. E25F 4 do For receptacle E25AF Br Do. E25F 4 do cover. For receptacle E25AB Br Do. E22T 6 do cover. For quadrant lamp bracket Br 190 by 5 A. S. E22M ? do E22P. For junction box E22N s M. E. std. 190 by 562 A. S. E22W 4 do For quadrant lamp bracket g M. E. std. 190 by 625 A. S. E23C 4 do E22P. For cover for receptacle Br M. E.std. 164 by 437 A. S. E21B ? . do E25J1. For junction box E21T or s M. E. std. 375 by 1 std. E22D 6 ... do E21U. For junction box E22N Br 164 by 0437 A. S. P45BB 1 do On terminal for grounG. con- Br M. E. std. 25 by 5 std. E21G ? do nection. For junction box E21T or Br 190 by 0.45 A. S. 2 Screws rd hd E21U. do Br ..... M. E. std. 190 by 0.2 A. S. 2 do On plug chain Br M. E. std. 190 by 0.375 A. S. 2 do On receptacle stud T95V Br M. E. std. For 1896 Mn only, 2 Split pins do Br 0.164 by 0.25 A. S. M. E. std. For 1896 Mn only, 1 do On cover for receptacle 0.156 by 1. 125 by 1 5. P65D1 1 Spring E25J1. do s 040 wire. T95A 1 do Br No 13 B. & S. T91Z 2 Straps well. Armored cable to carriage . . S gage. For 1896 Mn only. T91F q .... do do S Do. T91F ]> do do s For 1896 Mi only. T95W ? Studs For receptacle stud T95V . Bz For 1896 Mn only. E25X 9 Stuffing tubes For terminal tube E25AE Bz P45AN 1 Terminal c E25L1 9 Terminal clips For receptacle E25H1 p Bz E25L1 2 do For receptacle, E25.T1 P. Bz E25L1 9 do . . For receptacle E25AF P. Bz E25L1 9 do For receptacle E25AB P Bz E25F 9 Terminal screws flat fil. For junction b'ox P22N . . Br 0.190 by 0.875 A. S. E21P fi do For juuction box, E21T or Br M. E. std. 0.190 by 0.75 A. S. E22Z 4 do E21U. For quadrant lamp bracket, Br M. E. std. 0.190 by 0.687 A. S. E210 FU 9 do E22P. For junction box E21T or Br M. E. std. 0.190 by 0.875 A. S. E21U. M. E. std. 39 Names of parts of 12-inch mortar carriages, model of 1896 Mi and model of 1896 Mn. their piece marks, location, and material of which they are made Continued. ELECTRICAL EQUIPME NT-Continued. Piece mark. No. Name of part. Location. Material. Remarks. E25AL 4 Terminal screws, flat fil. For receptacle, E25J1 Bz ... 190 by : 85 A S. E25AL 4 hd. do For receptacle, E25AF Br... M. E. std! Do. E25AL 4 do For receptacle, E25H1 ^ Bz Do E21W 5 Terminal tubes For terminal tube, E21Z . . . Bz... E21R 8 Washers . For junction box, E21T or Br 375 diameter by E22H 2 do . E21U. For junction box E22N Br 0.031 thick, 0.193 hole. 375 diameter by T95B o Wire hooks On spring supporting F S 0.031 thick. 0.2 hole. slicked cord. AMMUNITION TRUCK, TYPE 12 M. B. [2 per carriage.] A3D A3C 1 1 44 1 4 1 1 1 1 2 2 1 1 2 2 1 1 2 2 2 2 2 2 1 1 2 2 4 2 2 1 1 1 1 4 1 2 1 2 4 100 4 2 1 1 2 2 1 2 2 2 2 2 2 2 2 Adjustable stop On bndv s 0.5 by 1.35. Hardened. 1 right, 1 left. With rubber tires. 1 right) 1 left. 2 right, 2 left. 0.5 by 0.75. For Nos. 1-62, inch For No. 62 and above. 0.375 standard. No. 14. 0.25. 1 right, 1 left. Axle ; Under front leg W I Balls For caster bearings s Body. Riveted on top of angles C S Bolts, with nuts . For brake-shaft brackets s Brake lever On brak-A shaft s Brake-lever guide On rear leg s Brake-lever spring Between brake lever and crosstie. In brake-shaft bracket s Brake shaft .. ' s Brake-shaft brackets Brake shoes On front and rear ties Bz... On brake shaft In front of body C.S s Buffer pin Buffer spring .do s Bushings Tn r>astpr whppls Bz Bz Cap . . 1 On buffer pin Bz Cap pin i In buffer pin s Casters In caster brackets Bz Caster ball bearings On caster S .. Caster brackets Riveted to rear leg Tn caster bracket C.S W. I Caster pins Caster roller pins In caster W I Caster wheels do g Crosstie On front and rpar tips s Front leg Under body s Front and rear ties Between front and rear legs. In handle-bar brackets Riveted to legs . . s. ... Handles White oak.. W. I.. Handle-bar brackets. . . Headless bolts For brake shoes s Keys do s do... For brake lever s Loading tray s. s... Name plate On body B/, do do . S B Oil plugs In wheels and shaft bracket . Bz Pin s Pins, escutcheon For name plate, A3D Br Under bod v... .. S.__. Rear leg Rings For caster ball bearing C Rivets ~Fnr <5hnt-trav shop. W T do For body and angles, etc . . . W. I In handle-bar brackets S Screws, No. 10, wood Screws, round head Set screw . . For name plate, A3C Br For brake lever . s Shot-tray shoe Riveted to front of loading tray. Rivp.fprl to bndv and Ip.srs Bz Side braces.. 8 Split pins ' In cap pin S do In buffer pin . S do. For adjustable stop pin S do . For caster nins. S do do For caster roller pins S Tn avlp S do In bnffp.r r>in . ' fi . Transoms . . Riveted to front and rear legs. On axlp. s Washers s Wheels.. do C S Names of parts of 12-inch mortar carriages, model of 1896 Mi and model of 1896 J///, their piece marks, location, and material of which they are made Continued. SHOT TONGS. [1 per carriage.] Piece mark. No. Name of part. Location. Material. Remarks. A8G ASH A8L ASM AST ASK 2 3 1 2 2 1 1 Claw, inner Opposite outer claw . S In two parts. Do. Riveted to claw. Do. Claw outer Pivoted on center pin S Dog... do S Pin, center In claws and dog : S Pin, shackle In shackle and outer cluw . . . Between two parts of outer claw. Between two parts of inner claw. On shackle pin and outer claw. In shackle pin S Separators s do Shackle S... s Split, pins s do Spreader In center pin S In outer claw S do In inner claAv S LANYARD ATTACHMENT. N17G 2 N17L N17A N17B1 N17D N17H1 N17K1 N17F N17E N17J 1 Bolts, with nuts Bridle ring For pulley bracket (N17K1). Cn lanyard (N17D) S Including 2 hooks. 0.25 by 0.375. For pulley. For button (N17A). Button Hook On end of lanyard (N17D1) . do C S s Lanyard (complete) Pulley Through racer to breech of mortar. In pulley bracket (N17K1). On pit ladder Hemp Bz Pulley bracket Bz... Screws, countersunk. . . . . Split pin For washer (N17J) In pulley bracket (N17K1). .do . . . S s Washer s do On racer C S ELEVATION QUADRANT. [Details marked * apply to quadrants Nos. 1 to 217, inclusive, only.] R19T I On bubble housing (R19U) Bz R19C 1 Arm sector In arm (R19T 1 ) Bz.. R19CA 1 In worm sector (R19Z) P Bz R19Q 1 Arm stop screw In bracket (R19R) S... R19R 1 Bracket On mortar trunnion Bz R19FA 1 On arm (R19T) Bz R19U 1 Bubble housing On bracket (R19R) Bz . R19X 1 In bubble housing (R19U) Bz R19EA 1 Bubble-housing retain- do S R19N 1 ing screw. do Bz R19E 1 Level vial do Glass R19J 1 Locking screw (upper) In worm (R19L) s R19K j do s R19B 1 Micrometer do G. S R19P j On micrometer lead (R19G) G S R19F 1 For micrometer (R19P) s R19G 1 screw.* do R19D 1 Micrometer retaining In arm (R19T) s R19V 1 screw. Index Under micrometer (R19B).. s... R19M 1 Index retaining screw In arm sector (R19C) s... 1 Pin In worm (R19L) s ... . 0.04 bv 0.12 driven. R19W 2 For bracket (R19R) Bz Required by Cl. 12, R19BA R19AA 1 2 Screw spring* For micrometer (R19P) .... For bracket (R19R) P. Bz Bz Div. 12 and 13. Required by Cl. 12 R19A 1 Sector spring In worm sector (R19Z) P.Bz R19DA 1 Washer On worm (R19L) S R19S 2 Washers * Fo r micrometer head G. S R19L 1 (R19G). In arm sector (R19C) s R19H 1 Worm nut On worm (R19L) Bz... R19Z 1 In arm (R19T) Bz 41 Names of parts of 12-inch mortar carriages, model of 1896 Mi ana "model of 1896 Mil, their piece marks, location, and material of which they are made Continued. GREASE CUP. [2 per carriage.] Piece mark. No. Name of part. Location. Material. Remarks. A2A A2B A2D1 A2E2 A2J A2H A2F A2C1 1 1 1 2 i ! i i Body Screwed into carriage .... Bz... 0.125 by 0.5 driven. Cap On upper end of body (A2A). Underneath plunger (A2E1). Underneath body (A2A) Bz...., CUD leather Leather C. Gaskets Pin Plunger In plunger (A2E1) , Bz In body (A2A) . Bz.. Plunger nut On plunger (A2E1) Bz Screw Cup leather to plunger Bz... Split pin For plunger and plunger nut. Between cap (A2B) and plunger (A2E1). Underc'up leather (A2D1) s Spring s Washer B7 1 Approximate weights of principal parts of 12-inch mortar carriages, model of 1896 Mi and model of 1896 Mil, as prepared for shipment. Number of loose pieces, crates, or boxes. Contents of each package. Weight (pounds). Remarks. Num- ber of parts. Name of parts. 1 1 1 1 1 2 4 1 2 1 1 1 4 1 Box 8 4 4 1 40 3 4 1 1 2 1 \ 6 1 Azimuth circle brackets 690 2,210 2,270 17,060 4,260 3,640 2,740 i 32, 430 238,380 233,315 7,200 2,730 1,725 5,875 3,520 915 12 bolts for 1896 Mi, 24 for 1896 Mil. For 1896 Mi. Do. For 1896 Mil. For 1896 Mi only. ...do.... ...do.... Loose... Box Crates . . do Vzimuth circle sections Azimuth circle sections, with ] 6 angles for platform. Base ring, traversing rack, and tap bolts Counter-recoil springs (20 small, 20 large), with 5 spring guide rods and 10 nuts for spring guide rods. Distance ring sections (each crate 1,820 pounds) . . . Floor plates (each crate 685 pounds) Racer Loose... ...do.... Side frames, with 2 cap squares (each frame 3,600 pounds). Spring box brackets Box.. . ...do.. . Loose. . Boxes . Box.. . Spring box Top carriage, complete Traversing rollers (each box 880 pounds) Traversing shaft pedestal, with cover, 8 cover screws a:id worm wheel. 1 Cast iron. 2 Cast steel. Weight of largest package in which remaining parts of carriages are shipped is 2.500 pounds. Total weights of carriages prepared for shipment: Model of 1896 Mi With cast-iron racer With cast-steel racer Model of 1896 Mn... Pounds. 102, 725 90, 718 WAR DEPARTMENT, OFFICE OF THE CHIEF OF ORDNANCE, Washington, January 11, 1916. Apr. 22, 1909. Revised March 18, 1913. Revised January 11, 1916. Form No. 1705. Ed. Aug. 24-17500. 997717 rfcj V-^-T *i ; aJKli' ' KUA YC 64344 3GC527 UNIVERSITY OF CALIFORNIA LIBRARY ~