CHAPTER THIRTEENDEMOLITIONS

8-1. CHARACTERISTICS OF EXPLOSIVES. There are two categories of explosives, Low and High.

a. Low Explosives are characterized by having a detonating velocity up to 1300 feet per second, producing a pushing or shoving effect.

b. High Explosives are characterized by having a detonating velocity between 3,280 - 27,888 feet per second, producing a shattering effect.

8-2. INITIATION SYSTEMS. Demolition systems are primed utilizing Modernized Demolition Initiators (MDI). MDI consists of blasting caps attached to various lengths of time fuse or shock tube. These blasting caps, along with a fuse igniter and detonating cord, can be used to create numerous firing systems.

8-3. MDI COMPONENTS.

a. Shock tube.(1) Thin, plastic tube of extruded polymer with a layer of special explosive material

on the interior surface.(2) Explosive material propagates a detonation wave which moves along the shock

tube to a factory crimped and sealed blasting cap.(3) Detonation is normally contained within the plastic tubing. However, burns may

occur if the shock tube is held.(4) Advantages of shock tube.

(a) The shock tube offers the instantaneous action of electric initiation without the risk of accidental initiation caused by radio transmitters, static electricity, etc.

(b) Extremely reliable.(c) May be extended using left over pieces from previous operations.

b. Blasting caps. Five MDI blasting caps are available which replace the M6 electric and M7 Non-electric blasting cap. Three of these are high-strength caps and two are low-strength.(1) High-strength blasting caps. Can be used to prime all standard military

explosives (including detonating cord) or to initiate the shock tube of other MDI blasting caps.(a) M11.

(1) Factory crimped to 30-foot length of shock tube.(2) A movable "J" hook is attached for quick and easy attachment to

detonating cord.(3) A red flag is attached 1 meter from the blasting cap and a yellow flag 2

meters from the blasting cap.(b) M14.

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(1) Factory crimped to 7 1/2 foot length of time fuse.(2) May be initiated utilizing fuse igniter or match.(3) Burn-time for total length is approximately five minutes. (4) Yellow bands indicate calibrated one minute time intervals.

NOTE: Burn time will increase with altitude and colder temperatures.

(c) M15.(1) Two blasting caps factory crimped to a 70 foot length of shock tube.(2) Each blasting cap has delay elements to allow for staged detonations.

(2) Low-strength blasting caps. Used as a relay device to transmit a shock tube detonation impulse from an initiator to a high strength blasting cap. NOTE: Low strength blasting caps cannot reliably set off explosives. They should only be used to set off additional shock tubes.(a) M12. Factory crimped to a 500 foot length of shock tube on a cardboard

spool. (b) M13. Factory crimped to a 1,000 foot length of shock tube.

c. M81 Fuse igniter. Used to ignite time blasting fuse or to initiate the shock tube of MDI blasting caps. NOTE: The M60 fuse igniter may still be used to ignite time blasting fuse. However, it will not reliably initiate the shock tube.

8-4. DETONATION SYSTEMS. There are two types of firing systems: MDI as a standalone firing system and combination (MDI and detonating cord).

a. MDI Firing system (Stand Alone). An MDI firing system is one in which the initiation sets and transmission and branch lines are constructed using MDI components and the explosive charges are primed with MDI blasting caps. Construct the charge in the following manner.(1) Emplace and secure explosive charge (C4, TNT, cratering charge, etc.) on

target.(2) Place a sandbag or other easily identifiable marker over the M11, M14, or M15

blasting cap to be used. (3) Connect to an M12 or M13 transmission line if desired.(4) Connect blasting cap with shock tube to an M14 cap with time fuse. Cut time

blasting fuse to the desired delay time.(5) Prime the explosive charge by inserting the blasting cap into the charge. (6) Visually inspect firing system for possible misfire indicators.(7) Return to the firing point and secure a fuse igniter to the cut end of the time fuse.(8) Remove the safety cotter pin from the igniter's body.(9) Actuate the charge by grasping the igniter body with one hand while sharply

pulling the pull ring.

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b. Combination (MDI and detonating cord) Firing system. Construct the charge utilizing the above steps for MDI stand alone system. Incorporate detonating cord branch lines into the system utilizing the "J" hooks of the M11 shock tube.

8-5. SAFETY CONSIDERATIONS.

a. MDI is not recommended for below ground use, except in quarry operations with water-gel or slurry explosives. Utilize detonating cord when it is necessary to bury primed charges.

b. Do not handle misfires downrange until the required 30 minute waiting period for both primary and secondary initiation systems has elapsed and other safety precautions have been accomplished.

c. Never yank or pull hard on the shock tube. This may actuate the blasting cap.

d. Do not dispose of used shock tubes by burning because of potentially toxic fumes given off from the burning plastic.

e. Do not use M1 dynamite with the M15 blasting cap. The M15 delay blasting cap should be used only with water-gel or slurry explosives.

8-6. DEMOLITION EFFECTS SIMULATOR (DES) Demolition Effects Simulators are a simple and cost effective way to conduct demolition training and rehearsals. DES charges can be constructed of materials immediately available through normal supply channels.

a. Materials.(1) Cardboard box (Not MRE box)(2) 1 roll 100mph Tape(3) Approx 2½ lbs 50/50 chalk/sand mix(4) Det Cord, approx 4ft(5) Cap, Blasting, M14 (6) Fuse Igniter, M81

b. Construction.(1) Cut out the cardboard box utilizing the template below (figure 13-1).

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Figure 13-1. DES template

(2) Assemble the box by folding along creases. Tape the box to prevent it from unfolding.

(3) Fill half of the box with a 50/50 mix of chalk and sand. Ensure no rocks or other large objects are the sand mixture.

(4) Place a Uli knot in the box.(5) Finish filling the box with the chalk and sand mixture.(6) Make a small hole in the top flap. Thread the free end of the detonating cord

through the hole at least 18 inches.(7) Close the top flap and completely tape the outside with 100 mph tape.(8) Prime charge utilizing desired amount of time fuse and M81 igniter.

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