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- Basic Formulas For Demolitions Use and Lacing
- ---------------------------------------------
-
- [1> Computation for minimum safety distance.
- For charges less then 27 pounds, the minimum safety distance is 900
- feet. Over 27 pounds, the minimum safety distance can be figured by using
- the following formula: ____________________________
- 300 x 3/ Pounds of explosive (T.N.T.)
- (Read: 300 times the cubic root of pounds of explosive)
-
- [2> Steel cutting
- When cutting, with explosives, part of a steel structure, determine
- the area in square inches of the member to be cut. This area is then labeled
- "A" and can use the following formula:
- P = 3/8 A
- P = The number of pounds of T.N.T. necessary.
- (Read: P equals 3 eighths times A)
-
- [3> Steel cutting
- When a steel member is not part of a greater structure, a different
- formula is used. This is based on the diameter of the individual member.
- 2
- P=D (Read: P equals D squared)
- P = The amount of T.N.T. required, and D is the diameter of the piece
- of steel.
-
- [4> Train rails
- To cut rails that weigh less then 80 pounds, use one-half pound of
- explosives. To cut rails that weigh over 80 pounds, use a full pound of
- explosives.
-
- [5> Timber cutting
- When the charge is to be external and untamped, the formula is as
- follows: 3
- P = C
- ---
- 30 (Read: P equals C cubed divided by 30)
- P = The pounds of explosives required, and C equals the circumference
- of the tree in feet (this formula is given for plastique).
- When figuring an internal tamped charge, the formula is:
- 2
- P = D
- ---
- 250 (Read: P equals D squared divided by 250)
- P = The pounds of explosives, and D equals the diameter of the tree
- in inches.
-
- [Some Important Principles]
- A basic rule to follow in all calculations having to do with explosive
- compounds is to round off the amount to the next highest unit package. At
- times you may use a little more than necessary, but you will be assured of
- success. Another rule when calculating charges is to add one-third more
- explosives if you do not intend to tamp. If a formula is given for plastique
- (composition 4), as was done for both timber-cutting formulas, you are able to
- compute poundage in TNT by adding one-third to the weight of the plastique.
- When using the principle of cratering to destroy a paved surface with
- explosives, use several charges rather than just one. The use of a bore hole
- is especially effective here. It is pointless to attempt cratering a roadway
- without tamping, since most of the destructive force of your charge will go
- straight up in the air.
- In the first two sections of this chapter, I have discussed explosives
- chemically and written about their safe handling. In the third section, I
- intend to go into their specific application. Bombs, like spies, have no
- allegiance, even to their creators.
- Bombs and booby traps incorporate more than just technical knowledge,
- they are based on human nature. To create an effective booby trap, one must
- have a primitive insight into his enemy's actions, thoughts, and methods.
- Before I get into the nitty-gritty of constructing booby traps, bombs, land
- mines, grenades, etc., it is important explain the basic working principles
- and mechanisms behind these devices.
- In the acquisition of equipment I would recommend purchasing or
- stealing, rather than making your own. Manufactured equipment is much safer to
- work with, and usually more effective. Once you have your explosive compounds,
- you will need a way to set it off, or detonate it. With all high explosives,
- you will need a detonator or blasting cap, unless you decide to lace the fuse
- into the explosive, although this is not recommended. A blasting cap is a low-
- explosive compound that is connected to a high explosive, for the purpose of
- detonating it. There are two types of blasting caps - electric and
- nonelectric.
- To use a nonelectrical blasting cap, one gently pushes the fuse into
- the hollow end, until it is fully in. He then crimps the hollow metal end
- around the fuse, and puts it into the high explosive. When the fuse burns down
- it ignites the flash charge. That in turn explodes the priming charge, which
- detonates the base charge, and finally creates enough heat to set off the
- high-explosive charge. The fuse is ordinary safety fuse or detonating cord.
- When the fuse is put into the blasting cap, it is necessary to seal
- it. This act of sealing is called crimping. When involved with this sort of
- thing, one must use the standard safety precautions set down in the
- previous section. Crimpers look like a pair of pliers, and their function is
- very similar, although pliers cannot be used for crimping. With the crimper in
- your right hand and the blasting cap in your left, slowly squeeze the hollow
- end of the blasting cap until it is firmly against the fuse. Use care so that
- you do not squeeze the charge within the cap, as this may detonate it.
- Whereas nonelectrical blasting caps are functional and have proven
- that they can be relied on, electrical blasting caps offer a much greater
- variety of uses. The basic principle of the electrical blasting caps is that
- an electrical charge moves through an insulated wire until it reaches a small
- section of that same wire which is not insulated and which is surrounded by
- a primary flash charge. The heat from the electrical charge will explode the
- flash charge, which in turn will set off a series of minor explosions,
- finishing up with the high explosive.
- Both types of blasting caps should be placed within the high explosive
- itself. This is easy when working with plastique or a pliable surface.
- Manufactured TNT has a small hole designed at the top for just this reason,
- but in dynamite one has to make his own hole. This hole should be made with a
- wooden or nonsparking metal object. The ends of the crimpers are ideal. The
- hole can be made in one of two ways: the first is bored carefully and gently
- straight down from the top of the stick, to exactly the length of the cap
- itself; the second type of hole is made from the side in a downward diagnol
- direction. Both of these methods have proven effective.
- Another method priming dynamite, which is not as reliable as either
- nonelectrical or electrical blasting caps, is called "lacing". The principle
- behind most detonating devices is simply to create a temperature which is hot
- enough to ignite the high explosive. This increase in temperature can be
- accomplished with a relatively good degree of success by weaving the fuse
- throughout the high explosive so that, as the fuse burns down, the heat
- created from the burning process it captures and held within the high
- explosive until the detonation temperature is reached.
- There are different methods of lacing, depending on what type of high
- explosive you happen to working with. For dynamite, the most common and most
- functional method is to literally sew the detonation cord into the stick.
- This preparation entails the individual's making several holes directly
- through the dynamite itself. This hole-making should be performed just as
- the planting of the blasting cap was handled. The holes must be dug gently
- and slowly with a nonmetallic instrument. "Lacing" should be done only when
- there is no alternative, and blasting caps are not available.
- When using TNT, you can lace it by wrapping the detonating cord
- around the body of the explosive at least five or six times, and then tying
- it off with a clove hitch. This will result in a great amount of heat being
- transferred into the TNT from the fuse, and its detonation.
- Plastique can also be ignited in this fashion, by employing a heavy-
- duty detonation cord, and tying a double knot in one of its ends. This large
- knot is then buried deep in the center of the composition. It must be at least
- one inch from any side.
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