摘要 |
Method of charging a borehole (15) with a column of explosives (as well as a blasting method) wherein the explosive charge is detonable simultaneously or in time-delay sequence by means of two or more electrically initiated detonators. The method requires providing a loop (8) of an insulated electrical conductor throughout the length of the borehole and, as the borehole is charged with explosives, sliding electrically actuable (time-delay) detonators along the looped wire (8) so as to be positioned at intervals throughout the borehole (15). The detonators are electrically coupled to the looped wire (8) by means of slidable toroidal transformer cores. The wire loop (8), in turn, is electromagnetically energized by means of a second transformer core (4) and an A. C. energy source (1). |