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.
[Illustration: 12" DISAPPEARING. (From Battery.)
FIG. 12.]
[Illustration: 12" DISAPPEARING. (in Battery.)
FIG. 13.]
[Illustration: 12" BARBETTE NON-DISAPPEARING.
FIG. 14.]
[Illustration:
UNITED STATES CARRIAGE
MODEL OF 1896
FOR
12 INCH B.L. MORTAR.
(Steel)
FIG. 15.]
[Illustration: LATEST MODEL 12" DISAPPEARING CARRIAGE AND GUN.
FIG. 16.]
[Illustration: 3" RAPID-FIRE GUN. (Pedestal Mount.)
FIG. 17.]
[Illustration: 5" RAPID FIRE. (Balanced Pillar Mount.)
FIG. 18.]
[Illustration: 3-INCH R.F. GUN (Masking Parapet Mount).
FIG. 19.]
[Illustration: 4.7 INCH 120 m/m Q.F. GUN ON CENTRE PIVOT PEDESTAL
MOUNTING.
FIG. 20.]
[Illustration: 4.7" Q.F. (Pedestal Mount.)
FIG. 21.]
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: 5" R.F. GUN AND BREECH MECHANISM.
FIG. 25.]
[Illustration: 4.7 INCH 120m/m QUICK FIRING GUN.
FIG. 26.]
[Illustration: 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.
[Illustration: 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.)
[Illustration:
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.
[Illustration: 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?
[Illustration: 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.
[Illustration: 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.)
[Illustration:
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
--------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
[Illustration: COMMON FRICTION.
FIG. 34.]
[Illustration: OBTURATING FRICTION.
FIG. 35.]
[Illustration: COMMON ELECTRIC.
FIG. 36.]
[Illustration: 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.
[Illustration: 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.]
Q. Explain the action of the combination fuse and name parts.
[Illustration: 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.]
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.
[Illustration: FRANKFORD ARSENAL TIME PERCUSSION OR COMBINATION FUSE.
MODEL 1900.
_a_ Body
_b'_ Compressed powder-ring
_b_ Retaining-ring
_b^2_ Brass ring }
_b^3_ Brass cup } Gas-check
_b^4_ Felt washer }
_c_ Time-train
_d_ Time-train cone
_e_ Cone-cover
_e'_ Drawn-brass waterproof cover
_e^2_ 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
_l^2_ Percussion-primer composition
_l^3_ 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)
_z^2_ 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_.
[Illustration: 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.
Q. How are the interiors of shells coated?
A. With a special varnish furnished by the Ordnance Department.
[Illustration: FRANKFORD ARSENAL 21-SECOND COMBINATION FUSE.
(Centrifugal.)
EXTERIOR
BEFORE ARMING
AFTER ARMING
FIG. 42.]
[Illustration: PROJECTILES.
SOLID SHOT CAST IRON.
CORED SHOT.
SHELL.
FIXED AMMUNITION.
SHRAPNEL.
FIG. 43.]
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.
FOOTNOTES:
[1] Sphero-hexagonal is no longer used.
[2] The minimum charge for mortars is, according to an endorsement from
the Chief of Ordnance, 18 lbs.
(C) CORDAGE, BLOCKS, TACKLE, GINS, SHEARS, ETC.
Q. Define yarn, strands, jaws of rope, short- and long-jawed rope,
guys, spun-yarn, marlin, standing rigging, running rigging, and a bight.
A. Yarn are called threads of hemp or other fibrous material which
compose a rope.
Strand is a number of yarns twisted together.
Jaws of rope are the interstices between the strands of rope.
Short-jawed rope is a rope tightly laid up together.
Long-jawed rope is a rope loosely laid up together.
Guys are stationary ropes to hold spars, such as pry-poles, shears,
etc., from falling.
Spun-yarn is made by twisting together very loosely two or more
well-tarred yarns. It is used for serving, seizings, stops, etc., and
is very pliable.
Marlin is also made of tarred yarns, but is tightly twisted and is much
harder and smoother than spun-yarn.
The bight of a rope is any part not an end.
A bight of a rope is formed by bending or doubling the rope so as to
form a loop.
Standing rigging are those ropes which are stationary.
Running rigging are those which run through blocks or pulleys. (See
Figs. 45 and 46.)
Q. Explain the difference between hawser-laid rope and cable-laid rope.
A. Cable-laid rope is composed of nine strands, and is made by first
laying up three ropes of three strands each with the sun, and then
laying the three ropes together into one, against the sun. Hawser-laid
rope must be coiled with the sun. Hawser-laid rope is a right-handed
rope, and cable-laid is therefore left-handed. (See Fig. 44.)
Q. How is the size of the rope denoted?
A. The size of the rope is always denoted in inches and fractions, and
is measured on the circumference. (See Fig. 44.)
Q. (_a_) How do you worm a rope? (_b_) Why?
A. (_a_) Worming a rope is filling up the divisions between the strands
by passing spun-yarn along them. (_b_) This is to render the surface
smooth for parceling and serving. (See Fig. 44.)
Q. (_a_) How do you parcel a rope? (_b_) Why?
A. (_a_) Parceling rope is wrapping narrow strips of canvas about it,
well tarred, put on with the lay of the rope. (_b_) To secure it from
being injured by rain-water or to prevent chafing or cutting of a rope
when a strain is brought against a rough surface or sharp edge. (See
Fig. 44.)
[Illustration: FIG. 44.]
Q. (_a_) How do you serve a rope? (_b_) Why?
. (_a_) Serving is the laying on of spun-yarn or other small stuff
in turns around the rope close together, and hove taut by the use of
a serving-board for small rope and mallet for large rope. Small ropes
are sometimes served without being wormed, as the crevices between the
strands are not large enough to make the surface very uneven. But a
large rope is always wormed and parceled before being served. (_b_) The
service is put on against the lay of the rope. (See Fig. 44.)
Q. (_a_) How do you whip a rope? (_b_) Why?
A. (_a_) Whipping is securing the end of a rope with twine. (_b_) To
prevent it from fraying out. (See Fig. 44.)
KNOTS AND HITCHES.
Q. Make the following knots and give the use of each: A square knot, a
bowline, single sheet-bend (weaver's knot), double sheet-bend, rolling
hitch, round turn and two half-hitches, clove-hitch, catspaw, blackwall
hitch, sheep-shank, a marlinspike-hitch.
A. See Fig. 45. This figure illustrates the manner of making these
knots. Their uses are as follows:
Square knot: A quick knot to tie two ends of rope together that will
not slip.
Bowline: To form a temporary eye at end of a rope. This knot can be
easily made and remembered by making a marlinspike-hitch and putting
the loose end of the bowline through the loop where the spike would go.
Single and double sheet-bend: To tie two ropes together. These knots do
not jam. When one rope is smaller than the other the double sheet-bend
is always used, making the double turn with the smaller rope.
Rolling hitch: For shifting the fall from one end of a windlass to the
other.
Round turn, two half-hitches, and clove-hitch: These are very useful in
securing the guys of a gin to the stakes, etc.
Catspaw: To apply the purchase or tackle to the fall of another.
Blackwall hitch: To fasten the end of a rope to a hook when there is a
steady strain on rope.
Marlinspike-hitch: Very useful in putting on lashings, etc.
Q. What is a strap or sling, and what is its use?
A. A strap or sling is formed by knotting or splicing together the ends
of a short strand of rope. It is used for hooking tackles into.
[Illustration: KNOTS
FIG. 45.]
[Illustration: FIG. 46.--SHORT SPLICE.]
[Illustration: FIG. 47.--LONG SPLICE.]
[Illustration: EYE SPLICE
FIG. 48.]
SPLICES.
Q. What is a splice?
A. Splicing is putting the ends of rope together by opening the strands
and placing them one into the other, or by putting the strands of the
rope between those of the bight.
Q. How is an eye-splice made?
A. Unlay the end of the rope for a short distance and lay the three
strands upon the standing part, so as to form an eye. Put the first end
through the strand next to it. Put the second end over the strand and
through the second, and then put the remaining end through the third
strand on the other side of the rope. Taper them as in the short splice
by dividing the strands and sticking them again. The eye-splice is used
to form a permanent loop in the end of a rope. (See Fig. 48.)
Q. How do you make a short splice?
A. Unlay the strands for a convenient length; take an end in each hand,
place them one within the other, and draw them close. Hold the end of
one rope and the three strands from the other in the left hand; if the
rope is large, stop them down to it with a rope yarn. Take the middle
strand, which is free, pass it over the strand which is first next to
it, then through under the second and out between the second and third
from it, and then haul it taut. Pass each of the six strands in the
same manner, first those of one end and then those of another. The same
operation may be repeated with each strand, passing each over the third
strand from it, under the fourth and through; or, as is more usual,
after the ends have been stuck once untwist each strand, divide the
yarns, pass one half as above described, and cut off the other half.
This tapers the splice. (See Figs. 45 and 46.)
Q. How do you make a long splice?
A. Unlay the ends of two ropes to a distance three or four times
greater than for a short splice, and place them within one another as
for a short splice. Unlay one strand for a considerable distance and
fill up the interval which it leaves with the opposite strand from
the other rope. Twist the ends of these two together, then do the same
with two more strands. The two remaining strands are twisted together
in the place where they were first crossed. Open the two last-named
strands, divide in two, take an overhand knot with the opposite halves,
and lead the ends over the next strand and through the second as the
whole strands were passed for the short splice. Cut off the other
two halves. Do the same with the others that are placed together,
dividing, knotting, and passing them in the same manner. Before cutting
off any of the half-strands, the rope should be well gotten upon a
stretch. Sometimes the whole strands are knotted, then divided, and the
half-strands passed as above described. This splice does not increase
the diameter of the rope, and it is used for splicing a fall or other
rope that runs through blocks. (See Fig. 45.)
RIGGING-TACKLES.
Q. What is a tackle?
A. A tackle is a purchase formed by reeving a rope through one or more
blocks for the purpose of hoisting or pulling.
Q. Name the parts of a block.
A. The shell, sheave, pin, and strap. (See Fig. 49.)
Q. Describe the following blocks: Single, double, treble, snatch, and
tail.
A. Single blocks have one sheave; double, two; treble, three. A
tail-block is a single block strapped with an eye-splice and having a
long end by which to make the block fast temporarily. A snatch-block is
a single block having a notch in one cheek to receive the bight of a
fall. (See Fig. 49.)
Q. What are the standing parts, the running parts, and the fall?
A. The standing parts are between the fasts and sheaves, the running
parts between the sheaves, and the fall the part held in hauling.
Q. Describe the whip.
A. A rope through a single block. (See Fig. 49.)
Q. What is the power gained if the block be fixed?
A. None.
[Illustration: FIG. 49.]
Q. Describe the whip upon whip.
A. The block of one whip is made fast to the fall of another. (See Fig.
49.)
Q. What is the power gained?
A. Double if only one block moves. Quadruple if both move.
Q. Describe the gun-tackle.
A. A rope passed through two single blocks and made fast to one. (See
Fig. 49.)
Q. What is the power gained?
A. Double. Treble if block to which rope is made fast moves.
Q. Describe the luff-tackle.
A. A rope hove through a single and a double block and made fast to the
single block. (See Fig. 49.)
Q. What is the power gained?
A. Treble. Quadruple if the block moves.
Q. What is a luff upon luff?
A. A luff-tackle on the fall of another luff. (See Fig. 49.)
Q. Describe the single Burton.
A. A rope rove through two single blocks, with a hook in the bight of
the running part.
Q. What is the power gained?
A. Treble. Quadruple if both blocks move.
Q. How is power determined when one tackle is applied to the fall of
another?
A. It is equal to the product of their respective powers.
Q. What is mousing, and what is its purpose?
A. A seizing around a hook to prevent it from spreading or unhooking.
(See Fig. 49.)
Q. What is a bight of a hook?
A. The middle of a bend of a hook. (See Fig. 49.)
GINS.
Q. Name the different parts of a garrison-gin.
A. It is composed of three poles (two legs and a pry-pole), braces,
a bolt, clevis, windlass, two handspikes, three shoes, and a
hoisting-apparatus consisting of two blocks (one triple and one
double). (See Fig. 50.)
Q. How much can be safely lifted with it?
A. 17,000 lbs.
[Illustration: THE GARRISON GIN.
FIG. 50.]
Q. How can the upper block be placed in position after the gin has been
raised?
A. By rigging a truce rope through the clevis and hoisting it up.
Q. Explain briefly how you would raise a gin.
SHEARS.
Q. Describe the parts of the shears.
A. Two spars lashed together at one point, forming an inverted V, the
ends being called heels, the upper end the head, and the part where the
lashing is applied is called the cross.
The equipment consists of the following stores: Two double blocks, two
single blocks for gin-tackles; one double block, one treble block,
and one snatch-block for the main-tackle fall; guys, head-lashing,
heel-lashing, and straps for main tackle; snatch-block, holdfasts,
and some spun-yarn for mousing, etc.; two cleats for heels to prevent
lashing from slipping; stakes for holdfasts for guys and heel-posts;
two shoes for heels. (See Fig. 44.)
Q. What are shears used for?
A. For lifting heavy weights over the face of a wall or cliff, or in
other situations where the gin could not be used for want of a footing
for the pry-pole.
Q. How do you pass a shear-lashing?
A. Middle the lashing and take a turn around both legs at the cross;
pass one end up and the other down, around and over the cross, until
half of the lash is expended; then ride both ends back again on their
own parts and knot them in the middle; frap the first and riding turns
together on each side with sennit. This will be useful in rigging
shears for hoisting guns when a gin is not available. Any two spars
that will support the weight can be used. (See Fig. 51.)
[Illustration: FIG. 51.]
Lay the middle of the back guy in the cross; bring the left-hand end up
around the right leg and over the head of the left leg; then carry the
right-hand end around under both legs; let it cross over the left-hand
end, and seize them together with spun-yarn.
Q. How is a square lashing made?
A. Place two spars at right angles and pass several turns around two
opposite angles of the X, then several turns around the other two
opposite angles. Continue this until the spars are firmly lashed and
will not move; tie the ends. This lashing is used to make two spars
rigid and at right angles to each other.
Q. How are shears rigged and raised?
A. Lay the heads of the spars on a trestle about three feet high, the
right leg above the left, so that they cross at about twice their
thickness from the ends, with the heels in their proper positions.
Make a bowline-knot in the end of the fore guy and slip it over the
head of both legs.
Lay the middle of the main-tackle strap under the cross above the fore
guy; bring the ends up over the cross; hook the upper block to them
under the cross below the fore guy and mouse it, taking care that the
splice comes in the middle of the strap and that the fall leads to the
rear.
Drive the heel-posts on each side the heels about a foot toward the
head and one foot outside; lay the shoes under the heels; make a
timber-hitch around the inner posts with the heel-lashings; pass three
turns over the legs below the cleats, and hitch the lashings to the
outer posts. Drive four holdfasts for each back guy, as follows: two on
each side the line of the legs prolonged, three feet apart, and two six
feet in the rear of these.
Lay the ends of the guy-straps over the front stakes; connect each pair
of front and rear stakes with a strap twisted up taut to insure the
strain being distributed properly.
Drive two holdfasts for the fore guy, one in the rear of the other, in
the prolongation of the axis of the shears.
Hook the upper blocks of the guy-tackles to a bowline in the end of the
guys, and the single block to the guy-strap, and mouse them all.
Ordinarily the fore guy can be worked without a tackle, belaying it
over the holdfasts, first taking a round turn over the one next the
shears. If not too heavy, the shears may be raised by lifting the head
and hauling on the guy-tackles, slacking the heel-lashings as required,
and tending the fore guy carefully to prevent the shears falling over
toward the rear.
Q. How are shears held in position after being raised?
A. By guys and holdfasts.
Q. What is the inclination or rake of the shears with the level of the
ground?
A. About 20 degrees.
Q. How can a change in the direction of the fall of the tackle be made
to lead to a capstan?
A. Hook the snatch-block to a strap placed below the cleat on either,
and pass the fall through it to the capstan.
HYDRAULIC JACKS.
Q. For what is the hydraulic jack used?
A. For lifting very heavy weights.
Q. What is the difference between the base jack and the horizontal jack?
A. The former has the lever, socket, etc., at the top of the jack,
while the latter has the working parts near the base. (See Figs. 52 and
53.)
Q. What is the principle involved in hydraulic jacks?
A. A pump operated by hand forces a small amount of alcohol through a
narrow valve into a recess containing a ram or large piston-rod. As the
alcohol is forced into this recess it raises the ram: thus a weight
upon the ram-head is raised. The alcohol is prevented from running back
into the main reservoir by valves similar to those on all pumps.
Q. What is the best liquid to use in filling jacks?
A. For the base jack one part alcohol, two parts water; for the
horizontal jack one part alcohol, one part water, and for both add a
tablespoonful of sperm-oil.
Q. Name the principal parts of a jack.
A. The cylinder, ram, reservoir, socket, knuckle, piston, piston-valve,
pump, pump-valve, lowering-valve, packing-springs, etc. (See Figs. 52
and 53.)
[Illustration: BASE JACK.
FIG. 52.]
Q. How can a weight be raised when the jack will not go under the
weight?
A. By the use of a movable claw.
Q. Give some general instructions for the care and use of the jack.
A. Never fill with water, kerosene, or wood-alcohol. Keep the ram down
when not in use. If the valve sticks on its seat, strike the lever a
few sharp blows up and down, thus jarring the valve. Use the alcohol
supplied by the Ord. Dept.
[Illustration: HORIZONTAL JACK
FIG. 53.]
Base jacks should never be used so that the head is lower than the
foot. A jack should be used once a week to keep the packing in order.
Never apply more than 150 pounds to the lever: this equals about the
weight of the average man.
THE U. S. MAGAZINE RIFLE.
Q. Point out the following parts of the Model 1903, Cal. 30 magazine
rifle:
Barrel,
Stock,
Butt,
Bayonet,
Bolt,
Trigger,
Sights,
Guard,
Cut Off,
Sleeve,
Sleeve Lock,
Stacking Swivel,
Extractor,
Ejector,
Windage Screw,
Firing Pin,
Cocking Piece,
Main Spring,
Follower,
Hand Guard,
Drift Slide,
Striker.
A. See Figs. 54, 55.
Q. Point out the following parts of the Ball Cartridge:
Case,
Primer,
Charge,
Bullet.
A. See Fig. 56.
Q. What is meant by the term caliber?
A. It is the diameter of the bore in inches.
Q. What is the trigger pull?
A. Three to four and one half pounds.
Q. What is the weight of the rifle and bayonet?
A. 9·69 pounds.
Q. What is the maximum ordinate at 1000 yards?
A. 21·26 feet.
Q. What is the weight of the bullet?
A. 220 grains.
Q. What is the weight of charge of powder?
A. 42 grains of smokeless powder.
Q. What is the muzzle velocity?
A. 2200 f. s.
Q. How many cartridges will the magazine hold?
A. Five.
[Illustration: FIG. 54.
U. S. MAGAZINE RIFLE, MODEL 1903.]
[Illustration: FIG. 55.
U. S. MAGAZINE RIFLE, CALIBER 30, 1903.]
[Illustration: FIG. 56.
CALIBER 30 BALL CARTRIDGE.]
Q. How is the rifle cleaned?
A. To clean the barrel, insert in the chamber a cartridge shell, the
front end of which has been filled with a wooden plug, and close the
bolt. Clean the bore with a rag saturated with soda water, or if this
is not obtainable, with water. Wipe dry with clean rags. Remove the
bolt and the cartridge shell, clean and dry the chamber from the rear.
Thoroughly oil the chamber and the bore with a light coat of cosmoline
oil. The stock and hand guard may be coated with raw linseed oil and
polished by rubbing with the hand.
Q. When is the multiball cartridge used?
A. In cases where the great range of the service bullet would endanger
persons or property at a considerable distance from firing.
Q. Of what is a multiball cartridge composed?
A. The service case charged with 34 grains of smokeless powder and two
round balls.
Q. What is the effective range of the multiball cartridge?
A. 200 yds., when sights must be set for 350 yds. At 100 yds. or less
fire point blank.
Q. Illustrate to the instructor how you would set the sight for a given
range, using both open and peep sights.
Q. To shoot to the right (or left), which way would you move the sight?
NOMENCLATURE.
(For Reference Only.)
COMPONENT PARTS.
(_One hundred and two in number._)
Barrel:
Barrel. }
Front Sight Stud. }
Front Sight Stud-Pin. }
Rear Sight Base. } Assembled.
Rear Sight Base Pin. }
Rear Sight Base. }
Spline. }
Bayonet:
Bayonet Blade. }
Bayonet Guard. } Assembled.
Bayonet Guard Rivets (2). }
Bayonet Catch.
Bayonet Scabbard Catch.
Bayonet Spring.
Bayonet Spring Cup.
Bayonet:
Bayonet Grip, right. }
Bayonet Grip Screw Washer. } Assembled.
Bayonet Grip, left. }
Bayonet Grip Screw Nut. } Assembled.
Bayonet Grip Screw.
Bolt:
Bolt. }
Extractor Collar. } Assembled.
Bolt Stop:
Bolt Stop Pin. }
Bolt Stop Spring. } Assembled.
Butt-plate:
Butt-plate.
Butt-plate Cap.
Butt-plate Cap Pin.
Butt-plate Cap Spring.
Butt-plate Cap Spring Screw.
Butt-plate Screw, large.
Butt-plate Screw, small.
Butt Swivel:
Butt Swivel. }
Butt Swivel Pin. } Assembled.
Butt Swivel Plate. }
Butt Swivel Plate Screws (2).
Cut-off:
Cut-off.
Cut-off Spindle.
Cut-off Spindle Screw.
Cut-off Spring.
Cut-off Spring Spindle.
Ejector.
Ejector Pin.
Extractor.
Firing Pin:
Cocking Piece. }
Firing Pin Rod. } Assembled.
Firing Pin Sleeve.
Follower.
Front Sight:
Front Sight.
Front Sight Pin.
Front Sight Movable Stud.
Front Sight Movable Stud Screw.
Floor Plate.
Guard:
Guard.
Floor Plate Catch.
Floor Plate Catch Pin.
Floor Plate Catch Spring.
Guard Screw, front.
Guard Screw, rear.
Guard Screw Bushing.
Hand Guard.
Lower Band.
Lower Band Spring.
Lower Band Swivel.
Lower Band Swivel Screw.
Magazine Spring.
Mainspring.
Rear Sight:
Base Spring.
Drift Slide. }
Drift Slide Pin. } Assembled.
Joint Pin.
Leaf.
Movable Base.
Rear Sight:
Slide.
Slide Binding Screw.
Slide Binding Screw Pin.
Slide Cap.
Slide Cap Screw.
Windage Screw.
Windage Screw Collar.
Windage Screw Knob.
Windage Screw Knob Pin.
Windage Screw Spring.
Receiver.
Safety-lock:
Safety-lock Spindle. }
Safety-lock Spring. }
Safety-lock Spring } Assembled.
Spindle. }
Safety-lock Thumbpiece. }
Sear.
Sear Joint Pin.
Sear Spring.
Sleeve:
Sleeve.
Sleeve Lock.
Sleeve Lock Pin.
Sleeve Lock Spring.
Stacking Swivel.
Stacking Swivel Screw.
Stock.
Striker.
Trigger.
Trigger Pin.
Upper Band.
Upper Band Screw.
APPENDAGES.
Cleaning Rod.
Front Sight Cover.
Oiler and Thong Case:
Oiler and Thong Case, Collar,
and Partition.
Thong Case Cap and Leather
Pad.
Oiler Cap and Dropper.
Oiler Cap Washer.
Screw-driver.
Thong and Brush:
Brush.
Thong Cord.
Thong Tip.
Thong Weight.