Abstract: An improved low-energy detonating cord, which is light-weight, flexible, strong, and non-conductive, detonates at high velocity, and is readily adapted to high-speed continuous manufacturing techniques, has a continuous solid core of a deformable bonded detonating explosive composition comprising a crystalline high explosive compound, preferably superfine PETN, admixed with a binding agent, the crystalline explosive loading being about from 0.5 to 10 grains per foot (0.1 to 2 grams per meter) of length; and, enclosing the core, a protective plastic sheath, e.g., about 0.005-0.075 inch (0.127-1.905 mm) thick, no metal or woven textile layers being present around the core or sheath. Perferably, one or more continuous strands of reinforcing yarn, e.g., running substantially parallel to the core's longitudinal axis, are located between the core and the plastic sheath, or in or around the sheath.

Abstract: A delay blasting cap having improved uniformity and predictability of delay time, and less susceptible to timing change as a result of a change in the medium or temperature surrounding the cap, has a polyolefin or polyfluorocarbon carrier capsule or tube for the delay charge, and preferably a rigid metal capsule holding the delay charge in place. Preferably, the delay carrier is a polyethylene capsule, which inhibits the priming charge from penetrating into the delay charge during the assembling of the cap.

Abstract: A surface delay device which exhibits good precision in delay timing when it is ignited from the side output of a low-energy detonating cord (LEDC) trunkline and end-initiates an LEDC trunkline or downline has a percussion-sensitive ignition charge wedged between the integrally closed end of a metal shell and the end of a delay capsule, which houses the delay and priming charges. An orifice in the end of the delay capsule between the ignition and delay charges is kept free of the ignition charge, e.g., by providing an axial recess in the end of the shell extending at least as far as the orifice. In the field the end of a cord is fitted into a well which is seated in the main detonating charge, adapted to be initiated by the priming charge; and another cord is positioned transversely against the ignition end of the shell.