Figure 5-1. TECHNIQUE FOR LIGHTING TIME FUSE WITH A MATCH 5-2. DETONATION (FIRING) SYSTEMS. The two types of firing systems are MDI alone, or MDI plus detonating cord. a. MDI Alone. An MDI firing system is one in which the initiation set, 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, such as C4, TNT, cratering charge, 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 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 such as cracks, bulges, or corrosion. (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. b. MDI and Detonating Cord. Construct the charge using the above steps for MDI stand-alone system. Incorporate detonating cord branch lines into the system using the "J" hooks of the M11 shock tube. Taping the ends of the detonation cord reduces the effect of moisture on the system. 5-3. SAFETY. MDI is not recommended for below ground use, except in quarry operations with water-gel or slurry explosives. Use detonating cord when it is necessary to bury primed charges. a. 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. b. Never yank or pull hard on the shock tube. This may actuate the blasting cap. c. Do not dispose of used shock tubes by burning because of potentially toxic fumes given off from the burning plastic. d. 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. e. Always use protective equipment when handling demolitions. Minimum protection consists of leather gloves, ballistic eye protection, and helmet. 5-4. EXPEDIENT EXPLOSIVES- IMPROVISED SHAPED CHARGE. An improvised shaped charge (Figure 5-2) concentrates the energy of the explosion released on a small area, making a tubular or linear fracture in the target. a. The versatility and simplicity of these charges make them effective against targets, especially those made of concrete or those with armor plating. (1) Bowls, funnels, cone shaped glasses, (champagne glasses with stem removed) used as cones. Champagne or cognac bottles are excellent. (2) Charge characteristics.