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Full text of "Instructions for mounting, using and caring for mortar carriages, model of 1896 MI and model of 1896 MII for 12-inch mortars, model of 1890 MI, April 22, 1909 ... rev. January 11, 1916"

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 



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