NOMENCLATURE AND GENERAL DESCRIPTION.
Q. What are projectiles?
A. They correspond to the bullets in small-arm cartridges.
Q. Why are projectiles made oblong and guns rifled?
A. To prevent the projectile from tumbling, thereby securing greater penetration, and better results in accuracy of fire.
Q. What is the difference between guns and mortars?
A. Guns are long in comparison with their calibers, mortars are short in comparison with their calibers.
Q. What is meant by a built-up gun?
A. One that is composed of several cylindrical forgings separately shrunk one over the other.
Q. Why are these forgings shrunk on?
A. To give an initial compression to the steel toward the bore, such that the strength of the gun to resist the pressure of the powder-gas will be increased.
Q. Name the principal parts of a built-up gun.
A. The tube, jacket, hoops, and trunnion-band. (See Figs. 5, 6, and 23.)
BUILT UP GUN. Fig. 5.
Q. What is a wire-wound gun?
A. One in which wire takes the place of the jacket and hoops and is wound over the tube. The wire is really in the form of a ribbon.
Q. Define the breech-reinforce.
A. That portion of the gun between the rear of the trunnion-band and the front of the breech. (Fig. 5.)
Q. Define the chase.
A. That portion of the gun between the front of the trunnion-band and the muzzle. (Fig. 5.)
Q. What is a barbette gun?
A. One that fires over a parapet.
Q. What two classes of barbette guns are there?
A. Barbette disappearing and barbette non-disappearing.
Q. What is the center of gravity?
A. That point where, if the gun were pivoted, it would balance. It is always near the trunnions.
Q. What is the difference between front-pintle and center-pintle carriages?
A. Front pintle is where the gun traverses about a point in the front part of the carriage; center pintle where it traverses about a point in the center of the carriage.
Q. What is a rack?
A. A bar or arc having teeth that engage in a gear-wheel or worm. (See Fig. 7.)
Q. What is a gear-wheel?
A. A wheel with teeth on the circumference.
Q. What is a bevel-gear?
A. Two wheels whose axles are at an angle to each other and whose teeth engage. (Fig. 8.)
Q. What is a miter-gear?
A. A bevel-gear with axles of equal-sized wheels at right angles. (Fig. 9.)
Q. What is a worm?
A. A gear-wheel in the form of a continuous screw. (Fig. 10.)
Q. What is a sprocket-wheel?
A. A toothed wheel that engages the links of a chain. (Fig. 11.)
Q. What is a spur-wheel?
A. A gear-wheel with teeth parallel with the axle of the wheel. If in Fig. 7 the rack were in form of a wheel, it would be a spur-wheel. (The pinion is also a spur-wheel.)
RACK AND PINION.
Fig. 7.
MITRE GEAR.
Fig. 9.
BEVEL GEAR.
Fig. 8.
WORM GEAR.
Fig. 10.
SPROCKET WHEEL AND CHAIN.
Fig. 11.
Q. Point out or describe the location of the following parts of a seacoast carriage:
Base-ring.
Foundation-bolts.
Leveling-bolts.
Upper-roller path.
Lower-roller path.
Traversing-rack.
Conical rollers.
Distance-ring.
Dust-guard.
Racer.
Chassis.
Top-carriage.
Recoil-cylinder.
Piston.
Piston-head.
Throttling-bars.
Followers.
Stuffing-box.
Packing.
Guide-hooks.
Trunnion-bed.
Trunnions.
Kim-base.
Cap-squares.
Cap-square bolts.
Elevating mechanism.
Traversing mechanism.
Azimuth circle.
Azimuth indicator.
Retraction-gear.
Sight standard.
Shot-hoist.
Crane.
Shot-hoist drum.
Pawl.
Elevating-arc.
Recoil-rollers.
Chassis-rails.
Gun-shield support.
Loading-platform.
Elevating-shaft.
Extra for R. F. guns:
Pillar-base.
Shoulder-rest.
Electric batteries.
Pistol-grip.
Range-drum.
Extra for disappearing guns:
Gun-lever.
Lever-axle.
Counterweight-shaft.
Counterweight.
Cross-head.
Cross-head guides.
Cross-head rack.
Tripping-bars.
Counter-recoil-buffers.
Gunner's platform.
Retraction-ropes.
Extra recoil-buffers.
Electric traversing-controller.
Electric elevating-controller.
A. See Figs. 12 to 22 inclusive.
BREECH-BLOCKS, RECOIL-CYLINDERS, ETC.
Q. Point out or describe the location of the following parts of the gun and breech mechanism of 8" and 12", Model 1888:
Bore.
Shot-chamber.
Muzzle.
Powder-chamber.
Forcing-cone.
Screw-box.
Breech-block.
Mushroom head.
Spindle.
Gas-check pad.
Vent.
Hinge-pin.
Rotating-crank.
Translating-roller.
Tray.
Breech-plate.
Slotted sectors.
Screw sectors.
Pinion- and gear-segment.
Vent-bushing.
Filling-in disc.
Exterior ring.
Interior ring.
Vent-cover.
Rotating-crank catch.
Obturator-spindle.
Obturator-spindle nut.
Locking-nut.
Translating-stud.
Guide-rails of tray.
Tray-latch.
Securing-latch.
Securing-latch catch.
Rotating-ring.
Rotating-pinion.
12" DISAPPEARING. (From Battery.)
Fig. 12.
12" DISAPPEARING. (in Battery.)
Fig. 13.
12" BARBETTE NON-DISAPPEARING.
Fig. 14.
UNITED STATES CARRIAGE
MODEL OF 1896
FOR
12 INCH B.L. MORTAR.
(Steel)
Fig. 15.
LATEST MODEL 12" DISAPPEARING CARRIAGE AND GUN.
Fig. 16.
3" RAPID-FIRE GUN. (Pedestal Mount.)
Fig. 17.
5" RAPID FIRE. (Balanced Pillar Mount.)
Fig. 18.
3-INCH R.F. GUN (Masking Parapet Mount).
Fig. 19.
4.7 INCH 120 m/m Q.F. GUN ON CENTRE PIVOT PEDESTAL MOUNTING.
Fig. 20.
4.7" Q.F. (Pedestal Mount.)
Fig. 21.
5" RAPID-FIRE GUN. (Pedestal Mount.)
Fig. 22.
(Continued from Q. on page 40).
For continuous-motion or "Stockett" mechanism the following:
Spiral-gear.
Crank.
Worm-shaft.
Worm.
Worm-wheel.
Catch-bolt.
Spring-bolt.
Tray-latch catch.
Spindle-ball bearing.
A. See Figs, 1, 2, 3, 4, 23.
CONTINUOUS MOTION BREECH MECHANISM.
Fig. 23.
Q. Point out or describe the location of the following parts of the 5" R.F. breech mechanism:
Block-carrier.
Hinge-pin.
Spindle-key.
Latch-bolt.
Latch-lever.
Lever.
Pinion.
Breech-block.
Gear-segment.
Vent-bushing (copper).
Exterior split ring (front).
Exterior split ring (rear).
Interior split ring.
Gas-check pad.
Filling-in disc.
Tripping-stud.
Latch-bolt seat.
Slide-housing.
Slide-stop.
Slide.
Slide-handle.
Contact-plate.
Firing-leaf.
Circuit-breaker housing.
Circuit-breaker spring.
Circuit-breaker contact-pin.
Firing-cable.
A. See Figs. 24 and 25.
Q. Point out or describe the following parts of the 4·7-inch quick-firing breech mechanism: Carrier-link, spindle, hand-locking lever, firing-pin, spring-catch, sliding-block, retaining-nut, bolt.
A. See Figs. 26 and 27.
5" R.F. GUN. SHOWING BREECH MECHANISM.
Fig. 24.
Q. Explain briefly how a breech-block of a heavy gun or mortar is dismantled.
A. The breech being open, remove the locking-nut and spindle-nut, place a block of wood against the spindle and gently hammer the mushroom head free from the gas-check pad, then remove it by hand. Pry the exterior and interior split rings free from the gas-check pad and remove them, also the filling-in disc. The spindle-washers can be removed at any time. The parts are assembled as follows: Adjust in the following order: the gas-check pad, exterior and interior split rings, filling-in disc, and spindle-washers. The spindle-washers must be put on after the spindle is put in. Then gently insert the spindle and screw on the locking- and spindle-nuts as prescribed for adjusting the gas-check pad.
5" R.F. GUN AND BREECH MECHANISM.
Fig. 25.
4.7 INCH 120m/m QUICK FIRING GUN.
Fig. 26.
4.7 INCH.
BREECH CLOSING AND FIRING GEAR.
Fig. 27.
Q. Point out or describe the following parts of the one-pounder subcaliber tube for the 12" B. L. R., model 1895:
Gun.
Adapter clamp-wedge.
Clamp-wedge screw.
Thread clamp-screw.
Rear adapter.
Center support.
Front adapter.
Adjusting-wrench.
Clamping-wrench.
Locating-gauge.
Clip-extractor.
Obturator spindle-plate.
A. See Fig. 28.
ONE-POUNDER SUBCALIBER TUBE.
Fig. 28.
Q. How should gas-check pads be adjusted before firing?
A. First: Close the breech.
Second: Loosen spindle and locking-nuts.
Third: Rotate block half-way.
Fourth: Tighten spindle and locking-nuts in the usual manner, rotate the breech-block home, and pad is adjusted.
Q. How far should a projectile be rammed?
A. Until the zero of the brass ring on the rammer comes flush with the face of the breech-plate. (See Fig. 29.)
SCALE ON RAMMER, TO INDICATE
PROPER TRAVEL OF PROJECTILE
FOR 8"-10"-12" RIFLE AND
12"-MORTARS
Fig. 29.
Q. Describe how to set the azimuth indicator-plate for a given azimuth.
A. Traverse the gun until the mark on the indicator-plate representing the number of hundredths is opposite the mark on the azimuth circle representing the number of degrees. In Fig. 30 the gun is set at 104°.05.
Fig. 30.
Q. How do you repack a stuffing-box?
A. If any of the old packing is used, it should be put in after the new. See that the stuffing-boxes are well cleaned and oiled.
Put on the piston-rod one ring of 1-inch Garlock'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, being careful to break joints until five rings of new packing have been inserted, or an equal amount of new and old when any of the latter is used. Place the gland on the follower, enter them together in the box and screw up the follower.
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 the pipe to the end of the spanner-wrench should not be permitted.
Q. How do you remove old packing from recoil-cylinders?
A. Remove the gland and follower (using new extractor, to be 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.
Extractor-bars are provided to be used for starting the packing from its seat, and by inserting the toes of the bar in the rack-teeth and prying over the edge of the box, being careful not to injure the thread.
Q. What is the object of the throttling-valve?
A. To regulate the flow of oil from the front to the rear of the recoil-cylinders. (See Fig. 31.)
Q. What precautions should be taken where the throttling-valve is provided?
GENERAL METHOD OF CONTROLLING THE ENERGY OF RECOIL IN GUN CARRIAGES.
Fig. 31.
A. That there is a lock on the valve to prevent any one from changing the setting without authority.
Q. Give some general directions for the care and preservation of guns and gun-carriages.
A. All guns and carriages should be elevated and traversed to their full limits daily. Ordinarily a gun and carriage should be painted at least once a year. However, climatic conditions may vary this rule. Sperm-oil, cosmic or light slushing oil should never be applied to a surface that has a suspicion of grit, moisture, or rust upon it. Brass gearing should have a thin film of sperm-oil or synovial oil on it. All oil-holes and recoil-cylinders should be examined daily at the beginning of drill. Special attention should be given to grease-cups on disappearing guns to see that they function properly. Retraction-ropes should be kept oiled and cleaned. No part of the carriage should at any time be allowed to rust, and if the carriage is to remain unused for short intervals, all bright and bearing parts should be covered with a thick coat of light slushing oil or cosmic. If the carriage is to remain unused for long intervals, the cosmic should be mixed with 25 per cent of resin. The mixture is well adapted for the purpose, but must be renewed from time to time. The rollers and roller-paths should be cleaned and covered with slush oil, and the space between the dust-guard and base-ring should be filled with waste or oakum to keep out dust, and wrench-holes inside base-ring should be plugged tightly with fitted wooden blocks.
To oil bore, use is made of an ordinary counter-brush secured to the end of a rod and provided with a half-disc of wood to keep the brush against the bore. By this means any required thickness of the mixture may be applied. The brush-rod is, for the rifles, fitted with a socket for connecting it with the special sponge-staff. For mortars the brush is supplied with a special handle. As a rule, the cosmic and resin mixture can be sufficiently removed from the bore for firing by using the scraper alone, this being a semicircular disc of iron.
Q. Describe throttling bars.
A. Bars of steel bolted on the sides of recoil cylinders. (The bolt heads can be seen on the outside of the cylinders.)
The piston head is slotted to receive the bars as shown in Fig. 31, and the bars are thicker at one end than at the other, this varies the amount of oil that can pass through the piston head slots and therefore the pressure keeps uniform.
CARE OF GUNS AND CARRIAGES.
(Extract from War Department, 1905.)
Circular }
No. 48. }
Light slushing-oil will be used on the different parts of breech mechanisms, including the threads on the block and in the breech recess, in bores of guns, and on all other bright steel or iron surfaces of mobile and seacoast armament, as a preservative when the material is to remain unused for an appreciable length of time. The slushing-oil will replace synovial oil as a lubricant for cross-head guides, etc., which should be given a light coating only. The use of light slushing-oil as a lubricant on breech mechanisms, including the threads on the block and in the breech recess, is forbidden: synovial oil will be used exclusively for lubricating the different surfaces of breech mechanisms, including the threads on the block and in the breech recess, on translating-screws and rollers, and in all oil-holes and on gears, etc., of carriages. Number 4½ lubricant only will be used in grease-cups. If exposed to rain within thirty hours after its application, all surfaces should be carefully examined and recoated if necessary. It can be applied by means of paint-brushes known as sash-tools No. 6, issued for that purpose. Except in very cold weather it can be applied in a thin uniform coat by using the brush, as when painting. During cold weather it should be applied by stippling—i.e., lightly tapping the surface with the end of the brush—the brush being held perpendicular to the surface to be covered. It can be applied to the bores of guns by means of the slush-brush issued for the purpose. In cold weather it should be warmed before being applied to the bores of guns. In all cases it should be applied in a thin coat, since this is all that is necessary to give good protection.
This oil can be readily removed by the use of burlap or waste dipped in kerosene oil. Lye dissolved in hot water and used while hot will also remove it, but not as satisfactorily as kerosene oil. In order to reduce the amount of kerosene oil to be used for its removal, a thick coating of slushing-oil when present should first be removed with a scraper before applying the kerosene.
Water without the addition of lye or kerosene should be used for cleaning bores of guns after firing. They should be permitted to drain and then be wiped dry before applying the slushing-oil.
Before applying the slushing-oil to any surface it should be thoroughly cleaned so as to be free from rust, water, kerosene oil, lubricating-oil, etc., as their presence will cause rusting underneath the slushing-oil. If applied to an oiled surface, the slushing-oil has been found to run off when heated.
On account of the superior protection afforded by this material it will not be necessary to completely remove it for inspection purposes as frequently as has been found necessary with the protecting materials heretofore used. Its frequent removal from a limited area will serve as an indication of the protection which is being afforded.
III. Mortars will hereafter be dismounted from their carriages once every twelve months, and the trunnions and trunnion-beds thoroughly cleaned, including the oil-grooves in the trunnion-bed liners.
The counter-recoil springs will at the same time be dismounted, the old paint removed, and each spring given two coats of new paint. The spring should not be reassembled until the paint is dry.
By order of the Acting Secretary of War:
J. C. Bates,
Major-General, Acting Chief of Staff.
Q. Describe the general parts of the throttling-valve and how it operates.
A. The two equalizing-pipes connecting the front and rear of opposite recoil-cylinders have a pipe connecting them; if this pipe is open completely, oil can move freely from the front to the rear of the cylinders. If it be closed partly by a valve called the throttling-valve, much less oil will pass this way. Thus, by regulating the adjustment of this valve, the recoil of the gun is regulated. It is seen that the throttling-bars work with the throttling-valve. (See Fig. 31.)
Q. How much oil should be removed from recoil-cylinders having the filling-plugs on the top of the cylinders?
A.
12-inch disappearing carriages, all models, 3 gallons.
10-inch disappearing carriages, all models, 1½ gallons.
8-inch disappearing carriages, all models, 1 gallon.
6-inch disappearing carriages, model 1898, ½ gallon.
Q. Where new filling-plugs have been inserted explain how the cylinders are filled.
A. For full charges remove the two filling-plugs (one from each cylinder), pour oil into one filling-hole until it flows out of the hole in the other cylinder, wait a moment to allow the oil to settle, and examine for any pocketed air or any temporary obstruction. If necessary, pour in more oil until the oil is observed to be in both cylinders up to the level of the filling-holes, then insert the screw-plugs without removing any oil.
Q. Prior to firing, what should be done to the bore of the gun?
A. Prior to artillery practice the bore, including the powder-chamber, of each piece to be used in practice will be thoroughly cleaned and freed from lubricant before any shot is fired.
Q. How is powder residue removed after firing?
A. After firing the bore may be cleaned by using a sponge covered with burlap well saturated with water. The bore should then be permitted to drain and thoroughly dry before being oiled.
Q. If any rust has accumulated on a bearing part, would you use sandpaper to remove it?
A. The use of sandpaper is forbidden, and emery-cloth No. 1, being coarse enough for any ordinary rusting, should be used, the rust being softened if necessary by kerosene.
Q. Describe the recoil-cylinder for mortars and its action.
RECOIL CYLINDER FOR MORTARS.
Fig. 32.
A. Fig. 32. When the mortar is fired, the piston is forced down, causing the piston-head to force oil through the oil-holes shown on the left of Fig 32. This oil passes through the oil-cavity upward and in rear of the piston-head. By opening or closing these oil-passages by withdrawing or inserting different-sized plugs the friction, hence the recoil, can be adjusted.
Note.—For steel mortars model '91 the plugs are as in Fig. 32; that is, from top to bottom: closed, ½, 0, 0, ½, closed, closed. For C. I. mortars '91: c., ½, 0, 0, ¾, c., c. For model '96 c., ½, ¼, 0, ¼.
Q. What are "grease-cups"?
A. Brass cups placed on the trunnions of guns to lubricate or oil the trunnions and trunnion-beds.
Q. How are they filled and adjusted?
A. Fill up to the bevel edge of the cup with the special oil provided by the Ordnance Department. The cup is then put on and screwed down until the plunger sticks out one quarter of an inch. By doing this a spring bearing on the plunger is forced to act, causing the plunger to press upon the oil, forcing it into the grooves and channels cut under the trunnions. The plunger should be kept at this distance (¼") from the cap by screwing down the cap from day to day. When the plunger will no longer be pressed out it is known that no more oil is in the cup, and it should be refilled.
Q. State some rules to be observed in painting guns and carriages.
A. The gun is painted gray, and the carriage olive-green. These are the only colors authorized. The entire surface of the gun is painted except where the console, or tray, touches the gun. Two coats annually are usually allowed.
Bronze trays will not be painted. Steel trays, excepting the upper and front surfaces and guide-rails, will be painted the same color as the gun. No parts of the breech-block or mechanism will be painted. The unpainted surfaces will be kept clean and bright with rottenstone and oil or "Putz-pomade."
All steel and iron non-bearing surfaces, both inside and out, will be painted. This includes the exposed parts of shafts (except squared ends), bottom plate of counterweight, ladders, cross-heads, cranks (not handles), cross-head pawls (except teeth), and large bronze pieces, including web and spokes of wheels and cylinder-heads.
The following parts are not painted: All wearing or bearing surfaces, which includes the handles of hand-wheels and cranks, teeth of all gear-wheels, teeth of cross-head pawls, teeth of cross-heads, elevating-rack guides, rollers and surfaces on which they travel, piston-rods, crosshead-guides, etc.
The bronze sight-holders will not be painted, nor will the azimuth and elevating-scales and pointers and the followers of the stuffing-boxes; these parts will be kept clean and, with the exception of the sight-holders, will also be kept bright with rottenstone and oil or "Putz-pomade."
The raised surfaces of letters and rims of direction and name-plates are to be kept clean and bright; the background of these plates will be painted the same color as the carriage.
Name-plates shall never be removed in painting the carriage. This is prohibited by orders.
Q. How is old paint removed?
A. Dissolve one pound of concentrated lye, powdered form, in six pints of hot water, and slake in enough lime to give the solution the consistency of paint. Use the solution freely mixed, and apply to the parts where paint is to be removed, with a brush preferably, or with waste tied on the end of a stick. When the solution begins to dry on the surface use a scraper to remove the old paint, and complete the cleaning of the surface with a mop and water. If one application is not sufficient to loosen the paint, apply a second coat. Before applying the new coat of paint wash the surface with liquid made by dissolving one half pound of washing-soda in eight quarts of water, and wipe dry. Let stand a sufficient length of time to have all parts thoroughly dry before painting.
Q. Should oil or grease ever be applied to the surfaces of electrical contacts on a gun or carriage?
A. No. Grease or oil acts as an insulator and prevents the current from passing the contacts.
Q. Point out or describe the following parts of a battery: Emplacement, parapet, traverse, parados, exterior slope, interior crest, interior slope, superior slope, interior wall, gun-platform, truck-platform, loading-platform.
A. See Fig. 14.
Q. Explain how to adjust the firing mechanism.
A. Insert the safety bar in the safety-bar notch of the slide housing. Slip the slide housing over the spindle, at the same time inserting the safety bar in its recess in the breech block. Press both home firmly. Slip on the yoke, pressing down until the notch above the ring is just visible. (In this operation it may be necessary further to adjust the spindle if the yoke does not go on completely, and the gas-check pad may have to be flattened for this purpose.)
Put the ejector in place with the ejector raised and the slide stop pulled out. Place the slide in position.
Q. When the weather is freezing what should be done to the recoil-cylinders before firing service charges?
A. A small amount of oil should be taken out and a reduced charge fired, then fill the cylinders and fire full service.
Q. Where should primers and fixed ammunition be kept?
A. Separate place from powder: never in the magazine. Primers should be kept preferably in the ammunition-chests, and fixed ammunition in the shot-room.
Q. How is the weight of a cored shot or plugged shell brought to standard weight?
A. By adding sand mixed with iron filings, water, or sawdust, according to the degree of increase required.
Q. How should throttling-bar bolts be adjusted?
A. First loosen them slightly, scrape away any paint that clogs them, and then tighten them to full limit.
Q. What is a priming-charge, and where is it placed?
A. A small charge of black powder in both front and rear of every section of cartridge.
Q. Should the trunnion-seats of sight-standards be polished? If not, why not?
A. No. Polishing wears away the brass and throws the sight out of adjustment. They should be wiped clean, however.
Q. Is the removal of the name-plates or sight-brackets authorized at any time?
A. No.
Q. How do you test the adjustment of the azimuth indicator?
A. Insert the bore-sights, traverse the gun until the line of sight through the front and rear bore-sights intersects a datum point whose azimuth is known. If the indicator reads this azimuth, the gun is in azimuth.
Q. How do you test the level of a carriage?
A. If the trunnion sight-bracket is correctly adjusted, place the telescopic sight upon it, set the sight and gun at zero elevation, and traverse the carriage to the full limits. If the bubble in the telescope-level remains stationary, the carriage is level. If not, adjust by turning the leveling-bolts.
POWDERS, PROJECTILES, PRIMERS, AND FUSES.
Q. How do you distinguish the following powders: Musket, sphero-hexagonal,[1] brown prismatic, black prismatic, and smokeless.
A. Musket is black and very fine grained. Sphero-hexagonal is black and in the shape of a small ball with a six-sided ring around it. Brown prismatic is brown, in the form of a six-sided prism with a hole in the center. All smokeless powder has the appearance of translucent celluloid and smells of ether. This powder grades in size according to the caliber of the gun, and has for large guns a cylindrical form with small holes running lengthwise in it. (See Fig. 33.)
MUSKET.
SPHERO-HEXAGONAL.
BROWN PRISMATIC.
MORTAR.
SMOKELESS POWDER.
Fig. 33.
Note.—The smokeless powder used in the U. S. Coast Artillery is made out of ordinary cotton waste. The process of manufacture is briefly as follows: The cotton waste is first thoroughly washed, cleaned, picked, and then put through shredding- and cutting-machines. It is then dried in ovens for many hours. It is then placed in pots and a mixture of strong nitric and sulphuric acid is poured over it. It is then washed in running water for many more hours. It is now called "guncotton." It is then dissolved with a mixture of alcohol and ether and put under a hydraulic press. On coming out of the press it looks like yellow gum. It is then forced through different sized dies, and in this shape looks like macaroni. It is then cut into various lengths and sizes, according to the caliber of gun for which it is to be used.
Q. Give the weight of charge, weight of projectile, and initial velocity of the piece to which your company is assigned.
A. See table on page 75. (Ref. Ordnance Department, G. O. 9, W. D. '08.) Slight variations from the requirements of this table will be permitted; but it is desired that these requirements shall be fulfilled as nearly as practicable.
Q. Name the different kinds of primers.
A. Common friction, common electric, obturating friction, obturating electric, and combination electric friction.
Q. Explain the action of the common friction and the obturating friction primer.
A. Its action consists in the friction of a saw-tooth wire being pulled through a portion of mercuric fulminate, which explodes and ignites a small charge of powder in the primer, which in turn ignites the main charge in the gun. (See Figs. 34 and 35.)
Q. Explain the action of the common and obturating electric primer.
A. Two insulated wires entering the primers are joined by a platinum wire. (A little guncotton is sometimes imbedded around the platinum wire.) The current heats the platinum, which ignites a small charge of powder or fulminate, if it be a common electric, in the primer, which ignites the main charge. (See Figs. 36 and 37.)
Table of Charges, Velocities, etc., for Rapid-fire and Seacoast Guns.
Weights of projectiles, powder charges, muzzle velocity, and pressure for rapid-fire and seacoast guns, service and practice charges.
| Column headings: | ||||||||||
| Col A: 1-pounder Subcaliber Tube. | ||||||||||
| Col B: 18-pounder Subcaliber Tube. | ||||||||||
| Col C: 6-pounder. | ||||||||||
| Col D: 15-pounder, Models of 1891 and 1902. | ||||||||||
| Col E: 15-pounder, Model of 1903. | ||||||||||
| Col F: 4-inch D.-S. | ||||||||||
| Col G: 4·72-inch Armstrong. | ||||||||||
| Col H: 6-inch Armstrong. | ||||||||||
| Col I: 5-inch O. D. Model, of 1897. | ||||||||||
| Col J: 5-inch O. D. Model of 1900. | ||||||||||
| A | B | C | D | E | F | G | H | I | J | |
| Weight of | ||||||||||
| projectile (lbs.) | 1·06 | 18 | 6 | 15 | 15 | 33 | 45 | 106 | 58 | 58 |
| Weight of charge | ||||||||||
| (lbs.): | ||||||||||
| Smokeless-- | ||||||||||
| Nitroglycerin | 1·25 | |||||||||
| { 40-7·5 | } | |||||||||
| Nitrocellulose | [2]2·5 | [2]7 | 1·35 | 5 | 6·06 | 7·5 | {45-10·5 | } 19 | 16·5 | 23 |
| {50-10·5 | } | |||||||||
| { 40-5·5 | } | |||||||||
| Cordite | { 45-8·2 | } 13·3 | ||||||||
| { 50-8·2 | } | |||||||||
| Brown prismatic | 12·0 | |||||||||
| Muzzle velocity | ||||||||||
| (f.s.): | ||||||||||
| Smokeless | 2100 | 750 | 2400 | 2600 | 2600 | 2300 | 2600 | 2600 | ||
| {40-2150 | } | |||||||||
| Cordite | {45-2570 | } 2150 | ||||||||
| {50-2600 | } | |||||||||
| Brown prismatic | 2000 | |||||||||
| Maximum permissible | ||||||||||
| pressure (pounds | ||||||||||
| per square inch) | 25000 | 18000 | 37460 | 34000 | 41000 | 34000 | 34000 | 34000 | 38000 | 36000 |
| Column headings: | |||||||||||
| Col K: 6-inch O. D., Model of 1897 M1. | |||||||||||
| Col L: 6-inch O. D., Model of 1900, 1903, and 1905. | |||||||||||
| Col M: 8-inch. | |||||||||||
| Col N: 10-inch R., Models of 1888 and 1895. | |||||||||||
| Col O: 10-inch R., Models of 1900. | |||||||||||
| Col P: 12-inch R., Models of 1888 and 1895. | |||||||||||
| Col Q: 12-inch R., Model of 1900. | |||||||||||
| Col R: 12-inch M., Models of 1886 and 1886-90 M1. | |||||||||||
| Col S: 12-inch M., Steel Model of 1890 M1. | |||||||||||
| K | L | M | N | O | P | Q | R | S | |||
| Weight of projectile | |||||||||||
| (lbs.) | 106 | 106 | 316 | 604 | 604 | 1046 | 1046 | 824 | 1046 | 824 | 1046 |
| Weight of charge | |||||||||||
| (lbs.): | |||||||||||
| Smokeless-- | |||||||||||
| Nitrocellulose | 29·75 | 39·1 | 80 | 155 | 205 | 275 | 325 | 33 | 33 | 62 | 54 |
| Brown prismatic | 135 | 280 | 490 | 75 | 75 | 105 | 105 | ||||
| Muzzle velocity | |||||||||||
| (f.s.): | |||||||||||
| Smokeless | 2600 | 2600 | 2200 | 2250 | 2250 | 2250 | 2250 | 1050 | 910 | 1300 | 1050 |
| Brown prismatic | 1975 | 2025 | 2025 | 1020 | 900 | 1150 | 1020 | ||||
| Maximum permissible | |||||||||||
| pressure (pounds | |||||||||||
| per square inch) | 38000 | 36000 | 38000 | 38000 | 38000 | 38000 | 38000 | 27500 | 27500 | 33000 | 33000 |
COMMON FRICTION.
Fig. 34.
OBTURATING FRICTION.
Fig. 35.
COMMON ELECTRIC.
Fig. 36.
OBTURATING ELECTRIC.
Fig. 37.
Q. Explain the action of the combination electric friction primer.
A. It is a combination of the two above principles, except that in the electric feature there is no return wire in the combination primer. The current comes in through the stem from the copper contacts on the firing mechanisms, heats the platinum, etc., and goes out through the case of the primer to the breech-block of the gun, thence to the trunnion and to the other pole of the firing-battery. This primer is also obturating. (Fig. 38.)
Q. What is an obturating-primer?
A. One which prevents the escape of powder-gas through the vent. (It need not necessarily be screwed into the vent.)
Q. What are percussion-primers?
A. Such as are used in fixed ammunition and go off by the snap of the firing-pin. They are commonly called caps.
Q. What are high- and low-resistance fuses?
A. A high-resistance fuse is one that requires a high initial velocity to cause the plunger to be released, and is therefore safer in handling. A low-resistance fuse does not require such a high initial velocity to cause it to act. Low-resistance fuses are provided with "safety-wires." (See Fig. 39.)
Q. What fuses are used in the United States service?
A. Frankford Arsenal base percussion, point percussion, and combination. The first two are of either high or low resistance, and vary in size for different calibers of guns. All fuses that are not "centrifugal" have become obsolete for all calibres above 1·65", except the combination fuse, but those on hand will be in service until used up.
Q. How are fuses inserted to make a tight joint?
A. By putting a special preparation, supplied by the Ordnance Department, on the threads. Never use red lead.
Q. Describe the action of a percussion-fuse and name parts.
A. On firing, the plunger-sleeve is forced to the rear and remains in this position during flight. On striking, the plunger and plunger-sleeve are forced forward and the prick-point of the plunger strikes the fulminate of the fuse; this ignites the priming charge in the fuse, which ignites the charge in the shell (Fig. 39).
Note.—There is a new fuse now prescribed for our artillery called "The Detonating Fuse." No one is permitted to take this fuse apart and its construction is kept secret.
COMBINATION ELECTRIC-FRICTION PRIMER.
NOTE: Current comes from the contacts at "A" passes through the platinum wire (heating it) out at "B" and thence to the body at "C" thence to the ground.
Fig. 38.
FRANKFORD ARSENAL BASE PERCUSSION FUSES.
Low. High.
| a | Body |
| b | Closing-cap |
| c | Primer closing-screw |
| d | Primer |
| e | Tin-foil disc |
| f | Primer-shield |
| g | Firing-pin sleeve |
| h | Firing-pin |
| j | Split-ring spring |
| k | Locking-groove |
| l | Brass-covering disc |
| m | Percussion-primer composition |
| n | Magazine powder-charge |
| w | Safety-wire |
| v | Vent |
Low Fuse, Model 1900.
Fig. 39.
Q. Explain the action of the combination fuse and name parts.
A. Before firing a hole is punched through the hole on the time-cone corresponding to time of flight at which it is desired that the projectile burst. On firing, the time-plunger strikes the firing-pin for the time-train, then the time-train begins to burn from the point where the hole in the cone was made, and at the end of the time of flight the flame reaches the interior of the fuse, thence to the shell. If this fails or it be desired to use the fuse as a percussion-fuse, the action is as in an ordinary percussion-fuse. Combination fuses are now always made with the centrifugal arming device as in percussion. (See Figs. 40 and 42.)
Q. What is a delayed-action fuse?
A. One which does not explode until a short time after striking.
Q. Explain the action of the new centrifugal fuse.
A. This fuse can act only when a rotary motion is given to it. This rotary motion, due to the rotating band, causes the plunger to bulge away from the center into two parts; when these parts separate it is seen from Fig. 41 that the firing-pin takes up a position parallel to the longer axis of the fuse and its point is almost touching the friction composition. When the projectile strikes, the plunger drives the firing-pin into the friction composition. The action is then the same as in the ordinary percussion-fuse. This fuse is therefore perfectly safe to handle, transport, or use. It becomes active only when a high rotary motion is given it. (See Figs. 41 and 42.)
Q. How are drill-primers loaded?
A. Insert a serrated wire with friction-pellet in the body of the primer, hold it in position with the assembling-tool, screw a rear wire or bottom wire (depending on whether it is an old- or new-model vent) fast to the serrated wire, fill with musket-powder, and close with a brass closing-cup, using the assembling-tool.
Q. Name the different kinds of projectiles in the United States service.
A. Solid shot, cored shot, shell, shrapnel, and canister. (See Fig. 43.)
Q. What is the rotating-band and what is its use?
A. The copper band near the base end. It is forced into the grooves of the rifling and causes the projectile to take up a rotary motion to prevent tumbling during flight.
Q. Why are some projectiles capped?
A. Experimental tests have shown that it will penetrate armor-plate deeper than those not capped.
FRANKFORD ARSENAL TIME PERCUSSION OR COMBINATION FUSE. MODEL 1900.
| a | Body | |
| b' | Compressed powder-ring | |
| b | Retaining-ring | |
| b2 | Brass ring | } |
| b3 | Brass cup | } Gas-check |
| b4 | Felt washer | } |
| c | Time-train | |
| d | Time-train cone | |
| e | Cone-cover | |
| e' | Drawn-brass waterproof cover | |
| e2 | Soldering-strip | |
| f | Cap | |
| g | Clamping-nut | |
| h | Time-plunger | |
| h' | Split-ring spring | |
| i | Safety-pin | |
| j | Connecting-tube | |
| k | Powder-charge | |
| k' | Powder-chamber closing-screw | |
| l | Percussion-primer | |
| l' | Tin-foil discs | |
| l2 | Percussion-primer composition | |
| l3 | Brass cup | |
| m | Concussion firing-pin | |
| n | Percussion firing-pin sleeve | |
| n' | Percussion safety-wire | |
| o | Percussion firing-pin | |
| p | Dowel-pins (2) | |
| q | Stud-pin | |
| r | Concussion-primer composition | |
| r' | Tin-foil disc | |
| ss | Vents (4) | |
| t | Split-ring spring | |
| w | Wrench-hole | |
| y | Tin-foil base-cover | |
| z | Bottom closing-screw | |
| z' | Base-vents (8) | |
| z2 | Locking-groove |
Fig. 40.
Note.—In punching fuse see that pin enters up to shoulder to insure penetration of cone d.
If fired for percussion-burst, punch at maximum time-setting but do not remove safety-pin i.
Ignition of time-train c is due to punched hole acting as vent for gases from primer-charge r and compressed powder-ring b.
FRANKFORD ARSENAL CENTRIFUGAL FUSES. BASE FUSE "S".
BEFORE ARMING. AFTER ARMING.
Fig. 41.
Q. What is the difference between shrapnel and canister?
A. Shrapnel is composed of a number of spherical balls in a cast-iron case, of the usual shape of a projectile, and has a bursting-charge in either the point or the base to scatter these balls. Canister is in a cylindrical case and has no bursting-charge. Shrapnel has a point combination fuse and is thus readily distinguished from all other projectiles. (See Fig. 43.)
Q. What is the difference between cored shot and shell?
A. Cored shot have hollowed centers, as also have shell, but in the latter the hollow is much larger. Owing to the recent manufacture of a suitable bursting-charge, cored shot can be filled with it and used the same as shell.
Q. What is the general color of the main body of all projectiles?
A. Black.
Q. How is the kind of metal of which it is composed marked?
A. By a painted band around the center, half-caliber wide.
Q. How is the degree of armor-piercing capacity marked?
A. By a greater or lesser portion of the head being painted with the color representing the metal of the projectile.
Q. How is the interior bursting-charge marked?
A. By a distinct color around the base below the rotating-band.
Q. Give the colors for the following metals:
| 1. Forged steel. | A. | 1. Blue-gray. |
| 2. Cast steel. | 2. Brownish gray. | |
| 3. Cast iron. | 3. Olive-green. | |
| 4. Chilled iron. | 4. Light olive-green. |
Q. Give the colors for the following bursting-charges:
| 1. Gunpowder. | A. | 1. Bright red. |
| 2. Maximite. | 2. Brown. | |
| 3. Explosive D. | 3. Yellow. |
FRANKFORD ARSENAL 21-SECOND COMBINATION FUSE. (Centrifugal.)
EXTERIOR
BEFORE ARMING
AFTER ARMING
Fig. 42.
PROJECTILES.
SOLID SHOT CAST IRON.
CORED SHOT.
SHELL.
FIXED AMMUNITION.
SHRAPNEL.
Fig. 43.
Q. How are the interiors of shells coated?
A. With a special varnish furnished by the Ordnance Department.
Q. How are canister painted?
A. Black all over.
Q. How are shrapnel painted?
A. The whole body black, with a band of bright red on the head below the fuse to indicate front charge, or on the cylindrical portion of the body in rear of the copper band to indicate base charge, depending on which class—base or front charge—it is.
Q. How are shrapnel distinguished from shell?
A. By the combination point fuse, which is always used with shrapnel.
Q. What is meant by fixed ammunition?
A. That in which the powder-charge and projectile are fixed; as examples, the ammunition for small-arm pieces and that for the 6-pdr. R.F. gun (which is made in the same way, only of a larger size), the powder being contained in a brass case, the projectile being fastened to the end of the brass case and a percussion-primer or cap being in the base of the same. (See Fig. 43.)
Q. Name the principal parts of a projectile.
A. The main body, the head, the bourrelet, the point, the base, and the rotating-band. (See Fig. 43.)
Q. In what kinds of projectiles are fuses used?
A. Shell, cored shot, and shrapnel.
Q. What is the rotating-band made of?
A. Copper.
Note.—Recent experiments have shown the superiority of a wider and heavier band. This new band will in all probability soon be adopted.
Q. Give some instructions for filling shell.
A. Unscrew and remove the plug from the shell. Place the filling-rod in the bag and fold the latter round the rod; insert it through the plug-hole, taking care not to force the end of the rod through the bottom of the bag; carefully push in the bag until the neck only is in the plug-hole, a portion being kept outside, as the whole bag must not be allowed to slip into the shell during the operation of filling; then withdraw the rod and insert the funnel into the neck of the bag, pressing the funnel well down into the plug-hole; pass the filling-rod through the funnel and gradually pour in a small quantity of the powder (say about half the charge); take out the funnel and rod, lift up the bag and jerk it, so as to "set" the powder well down to the bottom and to open the bag; then reinsert the funnel and rod as before, and continue the filling; choke the bag and cut off the superfluous choke. The filling-rod should be moved up and down while pouring in the powder, to facilitate its passage through the funnel, the powder in the shell being tamped on at the same time. The use of a large mallet against the side of the shell (any piece of wood will answer the same purpose) will materially assist in getting the maximum amount of powder into the shell.
When the shell is quite full withdraw the funnel and filling-rod, and tie the neck of the bag with two hitches of twine close to the top of the plug-hole. Cut off the superfluous choke, and push the neck of the bag well down the plug-hole into the shell, then screw in the plug as required.
Lead rings are supplied for the armor-piercing shell. The ring is hammered into the recess round the head of the plug, and the superfluous metal removed.
No preparation of the bag by pricking or otherwise is necessary.
Q. Suppose a projectile when weighed on a scale comes to 1044 lbs. and that it has a blue-gray head and a blue-gray band around its center of gravity, and below the copper band it is painted yellow; state what gun it is for, what kind of a projectile it is (whether a shell or solid shot), what it is made of, and if a shell, what is inside of it.
A. It is an armor-piercing shell for a 12-inch gun; it is made of forged steel, and is filled with explosive "D."
Q. What are shell and cored shot filled with?
A. Maximite, explosive "D," and rarely gunpowder.
Q. Why should shell always be coated carefully with a lacquer or varnish before being filled?
A. Because some of the explosives now used to fill shell, though perfectly stable and harmless in themselves, become very sensitive explosives when exposed to steel or iron. The slightest friction will sometimes detonate them.
Q. Why is red lead or white lead prohibited on fuse-threads?
A. Because, as with iron, some shell-fillers change into extremely sensitive explosives on contact with lead.
Q. Why should all fixed ammunition and primers be stored separately from magazines containing powder?
A. Because they are liable to explode by dropping or breaking, etc., and the shock of one primer or charge exploding might explode the whole magazine.
Q. Should rubber shoes be worn in magazines?
A. Yes.
Q. Why?
A. Because there are always priming-charges of black powder in every section of smokeless powder, and powder-dust from these might fill the air when opening cases, and a spark from a nail in a shoe on the concrete floor would ignite it. There is also a remote chance of the vapor of ether from the new smokeless powder exploding when in combination with the air.
Rubber matting on magazine floors would be best.