Method for placing and firing explosive charge for geological investigations using relatively small diameter boreholes and firing device

摘要

A relatively narrow bore hole (14) is drilled and compressed air, steam or water introduced to scoop out at the bottom the larger chamber (22) required to hold the charge (42). In a suitably slim container (36) the charge, together with the primer (34), is lowered into the chamber where the charge is forced out of the container to fill it and surround the primer. The container can then be withdrawn for further use