THE 3.2-INCH FIELD-GUN CARRIAGE.
NOMENCLATURE.
Wheel (1) consisting of tire; felloes; spokes; nave-box; nave-box flanges; nave-bolts and nuts.
Linch-pins (5); linch-washers (5); axle (6); shoulder-washers (7); brake-eyes and straps (8); axle-plates (9); flasks (10); upper front transom (11); lower front transom (12); middle transom (13); trail-box transoms (14); rear transom (15); lunette (16); lunette-plate (16); trail-plate (16); trail-handles (17); cap-squares (18); chin-bolt (19); eye-bolt (20); eye-bolt key (20); eye-bolt key-chain (20); trail-box (21); trail-box lid (21); trail-box lid-hasp (21); trail-box turnbuckle (21); sponge-bucket compartment (22); wheel-guard (23); handspike attachments, front and rear (24); handspike-socket (24); handspike socket-pin and key (24); handspike (24); handspike-clasps (24); long sponge-toggle and plate (25); short rammer and sponge attachment (26); short rammer and sponge-clasps (26); short rammer and sponge-clasp locking-catches (26); sponge-bucket toggle-hole (27).
Fig. 57.
Fig. 58.
Axle-seats (3), consisting of seat-plate, guard-rail, guard-rail standard, guard-rail catch, guard-rail hinge-pin, guard-rail locking-latch.
Bow-brake (2), [Fig. 59], consisting of shoe-piece (a), bow-springs (4) (b), bow-spring nuts and bolts (4) (c), attachment-socket (d), and the attachment consisting of clevis (e), clevis-bolt and nut (f), locking-lever (g), locking-bolt and nut (h).
Fig. 59.
The attachment-socket has a rectangular longitudinal mortice in which the tang of the clevis is placed. This tang has a slot, the lower part of which ends in a hole having the same diameter as the locking-bolt. The locking-bolt has bearings on each side of the mortice, and the part in the slot has two opposite rectangular grooves. When the bolt is in the hole with these grooves perpendicular to the slot, the clevis is locked; but when turned until the bottoms of the cuts are in prolongation of the slot sides, the tang of the clevis can be drawn out until stopped by the other end of the slot.
The Elevating Device (4), [Fig. 60], consists of frame and double lazy-tongs.
The Frame consists of (2) side-levers (c), pivot-bolt and separator (d), transom-bolt and nuts in rear, (2) eye-bolts, elevating-screw (f), cross-head elevating-screw nut, crank-handle (g).
The Lazy-tongs consists of (4) long arms (a), (4) lever-arms (a), (4) short arms (a), upper assembling-bolt, (2) assembling-bolts, short, (2) assembling-bolts, long, central journal-bolt (e), lower journal-rod (b) and (2) bearing-boxes, (2) eye-washers (for strap k), and the necessary nuts and washers.
The front end of the frame is attached to the carriage axle-plates, just in rear of the middle transom, by two eye-bolts which form the pivot.
Fig. 60.
The rear end is attached to the elevating-screw by the cross-head elevating-screw nut, which moves back and forth in the grooves in the side-levers in rear of the transom-bolt. The crank-handle on the elevating-screw is located just in front of the trail-box.
The double lazy-tongs (of two cells, the upper twice the size of the lower) are enclosed in the frame which furnishes bearings, at about the middle of the side-levers, for the central journal-bolt.
The lower journal-rod has fixed bearings in the two bearing-boxes which are bolted to the flasks of the carriage.
The gun rests on the upper assembling-bolt, which has eye-washers for the breech-strap.
Any motion of the elevating-screw handle raises or lowers the frame, and this, carrying with it the central journal-bolt, opens out or closes the lazy-tongs cells.
The Double-screw Elevating Device, [Fig. 60a], is used on 25 of the carriages for 3.6-inch guns. It consists of a hollow exterior screw (a) (having an exterior right-hand thread and an interior left-hand one) in which works an interior screw (c) to whose trunnioned head is attached the guide-strap (s), the arms of the strap being secured by nuts to the prolongations of the upper bolts that secure the middle transom. This insures rotation of the elevating device in a plane passing through the axis of the carriage. The bronze nut (b) in which a works is arranged on trunnions between the cheeks of the carriage, and has the hand-wheel (d) (or in some cases a large gear-wheel) so fixed to it that the latter can be rotated but has no motion of translation. A groove (e) is cut on the screw a, and a key on the hand-wheel fits this.
Fig. 60a.
Where the large gear-wheel is used motion is obtained by a small gear-wheel, axle, pinion, and hand-crank on the right of the trail.
DESCRIPTION OF CARRIAGE FOR 3.2-INCH GUN.
The carriage is made of steel. Its track, like that of the other vehicles, is 60 inches. The principal parts are the two flasks, connected by transoms, and the lunette; the two axle-plates, upper and lower; the axle-tree; the wheel-brakes; the wheels; the elevating apparatus; and the two seats.
Each flask is formed by riveting together two plates with curved margins; and the trunnion-beds are reinforced by bars of steel, which are enclosed between the margins of the flask-plates and riveted to them. There are three front transoms, upper, lower, and rear, in the vicinity of the trunnion-beds and axle-plates, and three trail-transoms at intervals between these plates and the lunette, the latter being riveted on. Trail-handles are on either side of the trail near the lunette. The lunette, lunette-plate and trail-plate are formed of one piece of metal. The axle-plates, two in number, which accurately envelop the solid steel axle, are riveted together.
The shoulder-washers are octagonal in form; to each is fitted a collar containing a stout eye, to which the brakes are attached. These collars have projections that embrace the axle-plates above and below to prevent turning of the axle within the plates. Linch-washers have a stud to keep them from revolving with the wheel.
Double-bow Spring-brakes, with a device for detaching them when necessary, are used. They are carried in a vertical position by means of the button on the lever and the groove on under side of axle-seat guard-rail. The spring-lever operates the locking-bolt in the end of the brake near the hook, so that the brake may be available in going up or down hill.
Axle-seats are placed on either side of the carriage. Underneath the left seat a section of picket-rope is carried.
The Elevating Device is of the lazy-tongs pattern, and is actuated by a handle on top of the flask. A leather strap is secured to the top part of the elevating device, and is used for strapping down the breech of the gun to avoid pounding.
Wheel, Archibald, height 57¾ inches, weight 200 pounds.
The Handspike, made of hickory, is sawn lengthwise into halves, and the wood thus removed replaced by 1/10-inch sheet iron, the whole riveted together and bound by iron bands. It is permanently attached to the flask, and when not in use is folded over on it and locked by the handspike-clasps.
The Short Sponges and Rammers are carried between the cheeks, between the upper and lower front transoms; grooved bronze ferrules in rear of the sponge-heads serve for the seats of the support and the clasps which hold them in place.
By means of the bronze hooks on the staff, one of which is movable, it is hooked to the right guard-rail when firing.
The Axle-seats are attached at the shoulder-washers to the axle-plates and bolted to the flasks.
The Long Sponge-staff is hinged near the middle, so that when folded the rammer-head is placed behind the sponge. It is carried on the left side of the carriage (the sponge-and rammer-heads under the axle-seat resting on the axle-plate), held by a toggle about midway of folded length.
The Tool-box is placed between the flasks, and has ample space for all tools required, and for tube-pouches, priming-wire, and gunner's gimlet. By means of a hasp and turnbuckle the lid is fastened to the side of the transom. In rear of the tool-box is an open compartment in which the sponge-bucket may be carried when empty. A hole between the seats of sponge and rammer provides for carrying the bucket, when filled, by its toggle.
Chin-and eye-bolts secure the cap-squares.
Wheel-guards are bolted on either side of the trail.
Weight of carriage and brakes, 1166 pounds.
Weight of carriage complete, with equipment, 1197 pounds.
Fig. 61.