(b) Common household items readily available may be treated and
assembled as an effective explosive device.
Other items for making bombs
are used widely in mining, agriculture, and some industry. Also, they are
not hard to produce.
(2) Common Explosives. Bombs are classified according to the time it
takes common explosives to burn or detonate. They are either low explosives
or high explosives. The slower acting low explosives have a pushing effect
in action, whereas high explosives have a shattering effect.
(a) Low Explosives.
1. Black powder is the oldest known explosive, but its use has
This is due to the development of more efficient explosives.
Black powder is granular, and the size of the grains varies for different
uses. In appearance, it is shiny black, and in burning gives off a heavy
white smoke. It burns freely in the open air, and it must be confined for
an explosive effect. It is used in pipe bombs and other improvised devices.
2. Smokeless powder is not a powder, and it is only smokeless
in comparison to black powder. It is made by treating plant fibers (cotton
or wood) with nitric and sulfuric acids to form nitrocellulose. It may be
used in pipe bombs and similar devices in the same way as black powder.
Generally, this powder has a more powerful effect.
(b) High Explosives.
1. Nitroglycerin is an oily, colorless liquid that explodes
violently. However, due to its sensitivity to shock, it is not widely used
in its liquid state.
When combined with other materials, it loses its
sensitivity. It is made into dynamite and plastic explosives.
2. Dynamite is the most widely used commercial explosive. (In
the military it may be classified as a low explosive.)
Basically, it is
nitroglycerin absorbed in a porous or absorbent material, such as sawdust.
The percentage of nitroglycerin varies, and other ingredients are added to
fit the intended use. It is packed in sticks, usually round, and covered
with paraffin impregnated paper. The strength is marked on the outside of
the wrapper. A blasting cap detonator is necessary to cause an explosion.
Sometimes dynamite is stored in one position for a long period, however. If
this is the case, the nitroglycerin tends to seep to the lower side and
becomes sensitive. Dynamite is convenient, available, and effective. These
qualities make it a favorite explosive for the saboteur. The high velocity
of its explosion makes it unnecessary to confine it to make an effective
3. Trinitrotoluene (TNT) is a yellow solid, usually formed
into blocks of various sizes. It is insensitive to shock, easy to handle,
and has powerful explosive properties.
Because of this, TNT is excellent
for sabotage purposes.