NARROW CAST BOOSTER CHARGES

摘要

The use of elongated booster or booster charges for initiating bulk explosives in boreholes provides advantages relative to conventional booster charges. Such booster charges are generally cylindrical in configuration and charges in accordance with this invention typically have a length-to-diameter ratio of at least 4:1, preferably greater than 4:1. In addition, the diameter of the booster charge is significantly less than the diameter of the borehole in which it is used, so that a significant amount of bulk explosive occupies the region in the borehole between the booster charge and the interior surface of the borehole. A vented stabilizer (14) is provided for combination with the booster in order to retain the booster centrally within the borehole. The stabilizer is preferably vented so that bulk explosive can flow through or past the booster and stabilizer assembly, and so that the assembly can be moved through the bulk explosive after the hole is filled.