Detonating Cord and Compatible Delay Systems

Detonating cord is a round, flexible cord containing a center core of high explosive, usually PETN (Pentaerythratol tetranitrate), within a reinforced waterproofing covering. Detonating cord is relatively insensitive and requires a proper detonator, such as No. 6 strength cap, for initiation. It has a very high velocity of detonation approximately equal to 21,000 ft/s. The cord’s detonation pressure fires cap sensitive high explosives with which it comes into contact. Detonating cord is insensitive to ordinary shock and friction. Surface as well as in-hole delays can be achieved by proper delay devices attached to detonating cord. A major disadvantage in the use of detonating cord on the surface is the loud crack as the cord detonates, and the possibility of grass and brush fires in dry areas.