4.31 FUSE DELAYS
It is extremely simple to delay explosive devices that employ fuses for
ignition. Perhaps the simplest way to do so is with a cigarette. An average
cigarette burns for about 8 minutes. The higher the "tar" and nicotine rating,
the slower the cigarette burns. Low "tar" and nicotine cigarettes burn quicker
than the higher "tar" and nicotine cigarettes, but they are also less likely to
go out if left unattended, i.e. not smoked. Depending on the wind or draft in
a given place, a high "tar" cigarette is better for delaying the ignition of
a fuse, but there must be enough wind or draft to give the cigarette enough
oxygen to burn. People who use cigarettes for the purpose of delaying fuses
will often test the cigarettes that they plan to use in advance to make sure
they stay lit and to see how long it will burn. Once a cigarettes burn rate
is determined, it is a simple matter of carefully putting a hole all the way
through a cigarette with a toothpick at the point desired, and pushing
the fuse for a device in the hole formed.
|=|
|=| ---------- filter
|=|
| |
| |
|o| ---------- hole for fuse
cigarette ------------ | |
| |
| |
| |
| |
| |
| |
| |
| |
|_| ---------- light this end
A similar type of device can be make from powdered charcoal and a sheet
of paper. Simply roll the sheet of paper into a thin tube, and fill it with
powdered charcoal. Punch a hole in it at the desired location, and insert a
fuse. Both ends must be glued closed, and one end of the delay must be doused
with lighter fluid before it is lit. Or, a small charge of gunpowder mixed with
powdered charcoal could conceivably used for igniting such a delay. A chain of
charcoal briquettes can be used as a delay by merely lining up a few bricks
of charcoal so that they touch each other, end on end, and lighting the first
brick. Incense, which can be purchased at almost any novelty or party supply
store, can also be used as a fairly reliable delay. By wrapping the fuse
about the end of an incense stick, delays of up to 1/2 an hour are possible.
Finally, it is possible to make a relatively slow-burning fuse in the
home. By dissolving about one teaspoon of black powder in about 1/4 a cup of
boiling water, and, while it is still hot, soaking in it a long piece of all
cotton string, a slow-burning fuse can be made. After the soaked string dries,
it must then be tied to the fuse of an explosive device. Sometimes, the
end of the slow burning fuse that meets the normal fuse has a charge of black
powder or gunpowder at the intersection point to insure ignition, since the
slow-burning fuse does not burn at a very high temperature. A similar type of
slow fuse can be made by taking the above mixture of boiling water and black
powder and pouring it on a long piece of toilet paper. The wet toilet paper
is then gently twisted up so that it resembles a firecracker fuse, and is
allowed to dry.
4.32 TIMER DELAYS
Timer delays, or "time bombs" are usually employed by an individual who
wishes to threaten a place with a bomb and demand money to reveal its location
and means to disarm it. Such a device could be placed in any populated place
if it were concealed properly. There are several ways to build a timer delay.
By simply using a screw as one contact at the time that detonation is desired,
and using the hour hand of a clock as the other contact, a simple timer can be
made. The minute hand of a clock should be removed, unless a delay of less
than an hour is desired.
___________________________________ to igniter from igniter
| |
| 12 | : :
| 11 1 | : :
| | : :
| 10 2 | : :
| o................|......: :
| | :
| 9 3 | :
| | :
| | :
| 8 4 | :
| o.........|...... :
| 7 5 | : :
| 6 | :.+.....-.....:
|__________________________________| __|_____|
| |
| battery |
o - contacts | |
..... - wire | |
|___________|
This device is set to go off in eleven hours. When the hour hand of the
clock reaches the contact near the numeral 5, it will complete the circuit,
allowing current to flow through the igniter or squib.The main disadvantage with this type of timer is that it can only be set for a maximum time of 12 hours. If an electronic timer is used, such as that in an electronic clock, then delays of up to 24 hours are possible. By removing the speaker from an electronic clock, and attaching the wires of a squib or igniter to them, a timer with a delay of up to 24 hours can be made. To utilize this type of timer, one must have a socket that the clock can be plugged into. All that one has to do is set the alarm time of the clock to the desired time, connect the leads, and go away. This could also be done with an electronic watch, if a larger battery were used, and the current to the speaker of the watch was stepped up via a transformer. This would be good, since such a timer could be extremely small. The timer in a VCR (Video Cassette Recorder) would be ideal. VCR's can usually be set for times of up to a week. The leads from the timer to the recording equipment would be the ones that an igniter or squib would be connected to. Also, one can buy timers from electronics stores that would be ideal. Finally, one could employ a digital watch, and use a relay, or electro-magnetic switch to fire the igniter, and the current of the watch would not have to be stepped up.
4.33 CHEMICAL DELAYS
Chemical delays are uncommon, but they can be extremely effective in
some cases. If a glass container is filled with concentrated sulfuric acid,
and capped with several thicknesses of aluminum foil, or a cap that it will eat
through, then it can be used as a delay. Sulfuric acid will react with aluminum
foil to produce aluminum sulfate and hydrogen gas, and so the container must be
open to the air on one end so that the pressure of the hydrogen gas that is
forming does not break the container. See diagram below.
_ _
| | | |
| | | |
| | | |
| |_____________| |
| | | |
| | sulfuric | |
| | | |
| | acid | |
| | | |---------- aluminum foil
| |_____________| | (several thicknesses)
|_________________|
The aluminum foil is placed over the bottom of the container and secured
there with tape. When the acid eats through the aluminum foil, it can be used
to ignite an explosive device in several ways.
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