Explosives are divided into two classes:
1. Low explosives.
2. High explosives.
To the first group belong all propellant explosives, i.e., all powders,
such as gunpowder and smokeless powders used in firearms.
To the second group belong:
(_a_) All explosives used in shells, torpedoes,
grenades, demolitions, etc.
(_b_) Detonators or exploders, i.e., explosives which
start explosive reactions in the explosives of Group (_a_).
=The characteristic of H.E.= is the extreme violence and suddenness of
their detonation.
In order to make them instantly pass from a solid or liquid form to
gas, they require a detonator or exploder, which applies a violent
shock to them and breaks down the chemical structure of the explosive
compound, and enables the flame to pass instantaneously throughout the
mass of the compound. This explosive is known as detonation.
=The composition of H.E.= almost without exception is some organic
substance, usually some form of carbon combined with nitrogen. Nitrogen,
one of the most inert gases known, owes its explosive value to this
very inertness; it combines so very reluctantly that on the least
provocation—such as shock—the compound of which it forms a part
instantly breaks up into gas, giving the enormous expansion needed for
explosive effect.
=Ammonal.= A gray powder. An Austrian explosive, picric acid plus
T.N.T. plus aluminum powder plus nitrate of ammonia plus carbon.
A very safe explosive—will not detonate when struck by rifle bullet,
but is very hygroscopic (collects moisture) and when in this condition
is liable not to detonate.
=Ballistite.= Consists of guncotton plus camphor or vaseline. Invented
by Nobel in 1888.
=Cordite.= Consists of nitro-glycerine 55 parts, plus guncotton 37
parts, plus vaseline 5 parts, plus acetone to harden, invented by Sir
W. Abel.
=Benzol.= Or Benzine, used extensively as a motor fuel contains a fair
percentage of toluene. (See T.N.T.)
=Coal Tar.= When subjected to fractional and low-temperature
distillation produces many by-products valuable in the making of H.E.
These distillations give off “light” and “heavy” oils of coal tar.
=Donnerite.= High explosive employed by German army in grenades.
=Dynamite.= See Nitro-glycerine.
=Fulminate of Mercury.= See Mercury.
=Guncotton=, or nitro-cellulose consists of cotton waste, purified,
dried, and heated with mixture of concentrated nitric and sulphuric
acid. Washed and reduced to a pulp and moulded into 1 oz. primers and
15 oz. slabs for service use. Is considered inferior to lyddite.
Size of wet slab of G.C., 6 × 3 × 1⅜ in.
Wet guncotton will not explode if hit by a bullet.
Wet guncotton can be sawn by a wet saw.
Requires dry primer, detonator and fuse to explode.
Dry guncotton will explode if hit by a bullet.
Dry primer of guncotton 1.35 in. diam., 1.15 in. diam. at ends, and
1.25 in. high.
Strength, 2½ times stronger than gunpowder, unconfined. Strength, 7 to
8 times stronger than gunpowder, confined.
Invented by Schombein in 1846.
=Gunpowder.= A mechanical mixture.
Saltpeter 75 per cent, plus charcoal 15 per cent, plus sulphur 10 per
cent. Rate of burning depends upon firmness of powder.
=Lyddite=, or picric acid. Consists of melted and solidified picric
acid. Vaseline is used to melt it. (See Picric Acid.)
=Mercury Fulminate.= Is made by dissolving three parts mercury in
36 parts nitric acid, keeping mixture at low temperature, and when
dissolved adding 17 parts of alcohol.
A small quantity of F. of M. placed on top of T.N.T. forms an excellent
detonating mixture. A great many German detonators consist of this.
Discovered by Howard in 1800.
=Melinite.= A French H.E., very similar to lyddite. Is picric acid
mixed with collodion. Introduced by Eugene Turpin.
=Nitro-glycerine.= Is produced by the action of nitric acid and
sulphuric acid on glycerine. Invented in 1847. When pure is a colorless
liquid. Explodes when heated to about 360° F.
N.G. in liquid form too dangerous to be used in practice. Was absorbed
in porous solid by Nobel in 1867 as dynamite. Porous solid used either
=kiesulguhr= or =fullers’ earth= used in percussion caps.
Relative strength 150 equals maximum
Blasting glycerine 150
Gelatine dynamite 130
Gelignite 110
Dynamite 100
Carbonite 55
=Picric acid.= A yellow crystalline prepared from coal tar. A
by-product of gas manufacture. The “heavy oil” of coal tar is boiled
and chemically treated, resulting in phenol or carbolic acid, which
separates from it. Carbolic acid is boiled sulphuric acid, and nitric
acid is carefully added, resulting in picric acid.
It is a very safe explosive and very powerful. Its chief fault is that
it forms “picrates” with metals or acid salts, some of which are more
sensitive to disturbing influences than the acid itself. To overcome
this the inside of all shells are varnished.
Pressure of picric acid equals 135,820 lb. on the square inch.
=Shimose.= Japanese H.E. Similar to lyddite.
=T.N.T.=, or tri-nitro-toluene or Toluol, largely used in German army
and navy. Is produced by heating toluene with mixture of nitric and
sulphuric acid.
Less powerful than lyddite, but is more stable and does not form
“picrates” and is not affected by water or air. Will not explode if hit
by a bullet.
Pressure T.N.T. equal to 119,000 lbs. per square inch.
=Tolite.= French name for T.N.T.
=Trilite.= Spanish name for T.N.T.
=Trotyl.= German name for T.N.T.
=Toluene=, or Toluol. Experiments made in 1899 at Karlsruhe produced
about seven pints of toluene from one ton of coal. The modern process
of low-temperature distillation of coal, however, greatly increases
quantity that can be obtained from each ton.
Is an aromatic colorless liquid hydrocarbon.
=Turpinite.= French H.E. similar to Melinite.
=Tetryl.= A coal tar product containing more nitrogen than T.N.T. or
lyddite. When mixed with a lead oxide it makes a less sensitive and
safer preparation than fulminate of mercury for detonators.
=FUSES=
=SERVICE FUSE=
=No. 11 Safety or Time Fuse=
=Description.= Color, black. Smooth surface.
=Time of Burning.= One foot in thirty seconds.
=Composition.= Train of slow match inside a wrapping of hemp or flax,
covered by layer of gutta-percha, surrounded by binding of black
waterproof tape.
=INSTANTANEOUS OR QUICK FUSE=
Color, red. Ribbed surface.
=Time of Burning.= Eighty feet per second.
=Composition.= Same as service fuse, except that it contains quick
match in place of slow match.
=Caution.= Instantaneous fuse must never be stored alongside safety
fuse.
=DETONATORS=
=SERVICE=
=No. 8 Mark VII=
=Description.= Copper tube open at one end painted red, marked on white
label, No. 8. M.K. VII containing 32 grs. fulminate of mercury.
=COMMERCIAL (Long)=
=COMMERCIAL (Short)=
=Description.= Copper tube, open one end, containing 25 grs. fulminate
of mercury.
=EXPLODERS=
=SERVICE=
=Guncotton.= One-oz. primer, 15-oz. slab. See Explosives, Guncotton.
=No. 2 Detonator for Hand Grenade.= Consists of brass tube (detonator
holder) with flat screw head. The other end is fitted with a cavity
which carries N.G. percussion cap. A commercial detonator open end
toward the screw head is placed inside, its open end closed with a
wooden plug; the closed end is pierced with four flash holes to enable
flash from percussion cap to communicate with F. of M. in detonator. A
brass screw in head of detonator holder closes detonator tube.
This detonator has three screw threads.
=No. 3 Detonator.= See description of No. 2. This detonator is ¼ in.
longer than No. 2, and has two screw threads.
=PATENT LIGHTERS=
=Nobel Lighter.= (See Plates 8 and 9.) The lighter is made up of two
cardboard tubes, one fitting over the other; inside the end of the
larger tube is a small brass cap containing friction composition. At
the top of the smaller tube are two friction points. These points are
held about ¼ in. from the cap containing friction composition, by a
safety pin passing through both tubes. At the other end of the smaller
tube is a small copper band into which the fuse can be crimped. A
narrow band of waterproof tape with a loose end is glued around the
joint of the two tubes to keep out moisture.
=To Assemble.= Insert fuse into lighter, fasten by crimping, and insert
other end of fuse into detonator. The joints at lighter and detonator
should be waxed to make it damp-proof and flash-proof.
=Brock Lighter.= See Grenade Hand. Consists of a small cardboard cup
filled with friction composition, covered with waterproof paper. The
latter can be torn off by pulling a small tag which is left free.
Grenades with fuses are so arranged (with sufficient length of fuse)
to explode from 3 to 5 seconds after being ignited and thrown, giving
the thrower plenty of time (when throwing from a trench) to bend down
safe. Grenades, without fuses (but with detonators only) will explode
on impact; for instance, in Grenade No. 1, Mark I, it is obvious when
instructions (see p. 2, Grenade 1) are carried out, and grenade is
thrown, that the steel needle will be driven into the detonator and
exploded.
In Grenade No. 3, Mark I, when safety pin is removed and releasing
socket slipped back, the wind vane revolves backward (during the
passage through the air) until far enough to allow the retaining
bolt to fall out. This leaves nothing between the firing needle and
detonator cap except a very thin spiral spring which is only strong
enough to hold the weight of the needle pellet until the shock of
impact when the grenade explodes.
In Grenade No. 20 releasing collar slips back on the rifle being fired.
In Grenade No. 5, Mark I. On this grenade being thrown the pressure
of the fingers being released the striking lever flies outward by the
pressure of the powerful spring, releasing the shoulder of the firing
striker which is driven on to the fuse and explodes in 4½ seconds.
All other grenades, see pages opposite plates.
=THROWING=
Hand grenades are held firmly in the hand behind the thrower, the arm
is brought quickly upward with a sweeping movement (the arm straight
all the time), the grenade will be let go when the hand is above the
thrower’s head, and should describe a semicircle in its flight.
Hand grenades can be thrown from 30 to 50 yards, rifle grenades from
200 to 400 yards.
Attacks should be practiced with dummy and deteriorated grenades, i.e.,
grenades with only a detonator and no explosive, etc.
Confidence and knowledge of grenades should be gained by students
handling, stripping and assembling all types and handling fuses and
detonators, as often as possible.
The importance of grenade work cannot be over-estimated and one can
imagine numberless cases when a grenade is more useful than any
other weapon. For instance, in street fighting a number of the enemy
are holding a house and firing from an upper window commanding the
main approach. You cannot get at them with a rifle, but it might be
comparatively easy for one or two men to get along to the house by back
ways, using the other houses for shelter and throw a grenade through
the window, killing everyone in the room.