OFR-22-78 Evaluation Of Alternatives For The Kelly Bar Method Of Loading Explosives

Includes a review of the state-of-the-art of explosives loading in the crushed stone and cement industries of South Florida and the development of a field test program for alternatives. Emphasis is on the loading of small diameter (2 1/4" or less) explosives. Test results ire evaluated for operational and economic feasibility. Details are described of an explosives loading method which involves placing cardboard tubes with external couplings through the hollow drill steel and then Loading explosives into the tube casings after the drill rig has moved off. This method eliminates the hazards peculiar to loading explosives Through the kelly bar. The alternative method can be performed by existing drill rigs with or without minor modification. With modification, improvement in yield per blasthole and/or primary crushing rate provides opportunity so offset some or all of the additional cost.