Abstract: A novel initiator (blasting cap) for explosives is provided. The initiator, which may be electric or non-electric, comprises a principal tubular metal shell containing a base charge, a delay charge, a priming charge and an ignition means, wherein the base charge and priming charge are housed within a reduced diameter tubular metal shell, which reduced diameter shell is located within but separated from the principal shell by a void space. The construction results in a markedly improved resistance against shock initiation.

Abstract: An exploding bridge wire (EBW) initiator assembly is provided which is particularly adapted for the initiation of an attached length of low energy shock wave conductor. The EBW comprises a hollow tube having an exploding bridge wire in one end of the tube, which directly initiates a length of shock wave conductor inserted into the opposite end of the tube. The entire assembly may be housed within a protective enclosure adapted for snap-fit connection with a source of electrical energy. The initiator can be initiated by relatively low voltage power supplies and is significantly safer than conventional EBW initiators.

Abstract: A method of blasting cap-sensitive, non-nitroglycerine-sensitized explosives and an initiating assembly for use in the method are provided. The method comprises initiating a column of the explosives by directing two radial/forward shock forces from an initiator assembly substantially simultaneously along the column of the explosives towards each end of the column. The initiating assembly of the invention comprises at least two initiators assembled side-by-side so that their explosive ends are opposite. A moulded plastics holder (6) for holding two blasting caps (1, 8) in the required spatial relationship is also described.

Abstract: A method of blasting cap-sensitive, non-nitroglycerine-sensitized explosives and an initiating assembly for use in the method are provided. The method comprises initiating a column of the explosives by directing two radial/forward shock forces from an initiator assembly substantially simultaneously along the column of the explosives towards each end of the column. The initiating assembly of the invention comprises at least two initiators assembled side-by-side so that their explosive ends are opposite. A moulded plastics holder (6) for holding two blasting caps (1, 8) in the required spatial relationship is also described.

Abstract: A system is provided for initiating a blasting cap wherein pulsating light energy is converted to electrical energy. An optical coupler couples the source of energy to a remote firing arrangement to transfer the generated pulsating light energy to the firing arrangement. An electrical connection connects the firing arrangement to an ignition resistor in a detonator. Thus, the generated light energy is converted to electrical energy and is transferred to the ignition resistor, the transferred electrical energy being the firing energy for the ignition resistor.

Abstract: A novel initiator (blasting cap) for explosives is provided. The initiator, which may be electric or non-electric, comprises a tubular metal shell having within a base charge, a delay train, a priming charge and an ignition means. Interposed between the delay train and the priming charge is an annular collar or ring of resilient material in contact with the inner wall of the metal shell. The construction results in a markedly improved resistance against shock initiation.