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. ************************************************