PRIMING DYNAMITE

2-35. Dynamite can be primed at either end or side using either the nonelectric, electric, or detonating cord priming method. These methods are discussed in the paragraphs below.

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2-36. There are three methods for priming dynamite nonelectrically and electrically. They are the—

z End-priming method (Figure 2-18). Perform the end-priming as follows:

„ Step 1. Making a cap well in the end of the dynamite cartridge using M2 crimpers. „ Step 2. Inserting a fused blasting cap into the cap well.

„ Steps 3 and 4. Tying the cap and fuse securely in the cartridge with a string.

z Weatherproof, end-priming method (Figure 2-18). Perform the weatherproof, end-priming

method as follows:

„ Step 1. Unfolding the wrapping at the folded end of the dynamite cartridge and making a

cap well in the exposed dynamite using M2 crimpers.

„ Step 2. Inserting a fused blasting cap into the cap well.

„ Step 3. Closing the wrapping around the fuse and fastening the wrapping securely with

string or tape and applying a weatherproof sealing compound to the tie.

Figure 2-18. Nonelectric and Electric End-Priming of Dynamite

z Side-priming method (Figure 2-19, page 2-18). Perform the side-priming method as follows:

„ Step 1. Making a cap well (about 1 1/2 inches long) into the side of the cartridge at one end

using M2 crimpers. Slightly slant the cap well so the blasting cap, when inserted, will be nearly parallel to the side of the cartridge and the explosive end of the cap will be at a point nearest the middle of the cartridge.

„ Step 2. Inserting a fused blasting cap into the cap well.

„ Step 3. Tying a string securely around the fuse, and then wrapping the string tightly around

the cartridge, making two or three turns before tying it.

„ Step 4. Weatherproofing the primed cartridge by wrapping a string closely around the

cartridge, extending it an inch or so on each side of the hole to cover it completely and covering the string with a weatherproof sealing compound.

Figure 2-19. Nonelectric and Electric Side-Priming of Dynamite

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Detonating cord can be used to prime dynamite. Using the M2 crimpers (about 1 inch from either end of the dynamite charge), four equally spaced holes should be punched through the dynamite cartridge (Figure 2-20). The cartridge must be rotated 180˚ after punching each hole to keep the holes parallel. Detonating cord should be laced through the holes in the same direction that the holes are punched. The dynamite will break if the loops of the detonating cord are pulled too tightly. To secure the detonating cord tail, pass it between the detonating cord lace and the dynamite charge.

Figure 2-20. Priming Dynamite With Detonating Cord

PRIMING 40-POUND, COMPOSITION H6 CRATERING CHARGES

2-37. The 40-pound, composition H6 cratering charge is primarily an underground charge; therefore, prime it only with composition C4 primed with detonating cord. Use dual-priming to protect against misfires as follows:

z Step 2. Dual-prime a single cratering charge by placing the primed composition C4 packages

parallel to the cratering charge and on opposite sides of it and flush with the top. Firmly hold them in place with duct tape. Instructions and markings on the canister indicate the exact placement of the composition C4 (Figure 2-21, Diagram 2, page 2-20).

z Step 3. Dual-prime two cratering charges by priming them in the same borehole. This requires

one primed composition C4 block on each of the cratering charges, parallel to the charges and flush with the top. When placed in the borehole, the composition C4 blocks are placed on opposite sides of the 40-pound charges (Figure 2-21, Diagram 4).

z Step 4. Ensure that the detonation-cord branchlines (from the composition C4 block) are long

enough to reach the detonating-cord ring mains after the cratering charge is in the ground. To aid in clearing possible misfires, place tape on the detonating cord from the cratering charge, 1 foot up.

2-38. The composition H6 cratering charge replaced the 40-pound ammonium-nitrate cratering charge. If an ammonium-nitrate cratering charge is drawn from an ammonium supply point (ASP), use the following steps to prime it:

z Step 1. Dual-prime a single cratering charge by placing the detonating cord into the detonating

cord tunnel. Tie an overhand knot with a 6-inch tail at either lower end of the length of the detonating cord. Use a minimum of 1 pound of explosive when dual-priming a single cratering charge. Prime the explosives with detonating cord and tape the charge to the center of the cratering charge (Figure 2-21, Diagram 1).

z Step 2. Dual-prime two cratering charges by priming only the detonating cord tunnels of each

charge when placing two charges in the same borehole. The borehole is dual-primed and extra explosives as shown in Figure 2-21, Diagram 3.

Figure 2-21. Priming Composition H6 and Ammonium Nitrate Cratering Charges

z Step 3. Ensure that the detonating cord branchlines from the 1-pound charge are long enough to

reach the detonating cord ring main after the cratering charge is in the ground. Place tape on the detonating cord 1 foot up from the cratering charge to aid in clearing possible misfires.

WARNING

Do not prime cratering charges with blasting caps when buried. Failure to comply could result in immediate personal injury or damage to equipment.

CAUTION

Ammonium nitrate is hygroscopic and ineffective when wet. Therefore, inspect the metal container for damage or rust. Do not use damaged or rusty charges. Personal injury or damage to equipment may result from long-term failure to follow correct procedures.