Abstract: A detonator 10 includes an elongate tubular member 12 which defines a longitudinally extending passage 14. A pair of base charges 16 and 20 are located in the passage 14. A primary charge 18 which is substantially disc-shaped is located in the passage 14 and is sandwiched between the base charges 16, 20 such that, upon initiation of the primary charge 18, a shock front generated by the primary charge 18 is propagated by the base charges 16, 20 in a bidirectional manner.

Abstract: A low energy fuse which has a tubular casing that is deformed at at least one end and intermediate its ends to form valve formations. Each valve formation defines a valve that is normally substantially closed and which is opened, in use, by a shock wave. Wall material of the casing may be deformed by heated displaceable forming elements. The deformed wall portions may be fused or bonded together to form an hermetic seal, the fusion or bond being sufficiently weak to be ruptured by the shock wave. Instead the deformed wall portions may merely touch one another or may be spaced slightly apart to define an aperture which is substantially smaller than the cross-sectional area of the casing.