The Effects of Shielded Tote Bins on the Safe Separation of 168 Pounds of Composition A-7Explosive.

摘要

This program was carried out to determine the minimum safe separation distance between stainless steel tote bins protected with Kevlar shielding. Each tote bin contained 168 pounds of Composition A-7 traveling on a simulated conveyor system within a tunnel or ramp. Full-scale tests were conducted to determine: (a) the effectiveness of the Kevlar shield, (b) the minimum safe separation distance in a steel-fiberglass tunnel configuration, (c) the source of detonation and-or propagation, either primary (tote bin) or secondary (conveyor) fragments, or both, (d) the safe separation distance in a wooden-fiberglass tunnel, and (e) the effects of confinement on detonation and-or propagation of acceptors. The results of this study are briefly summarized as follows: (1) the thickness of Kevlar tested was ineffective in preventing ignition at 130 feet in a steel tunnel configuration. Even though propagation (detonation) did not occur, a fire broke out at this distance. (2) Primary fragments (tote bin) were the most likely source of detonation and-or propagation. (3) No propagation was observed at 130 feet when a wooden-fiberglass structure was used. (4) Blast-focusing due to the presence of the tunnel walls can affect the trajectory of the fragments as well as the flight velocity. In the Composition B production line at Holston Army Ammunition Plant, interline distances greater than 130 feet between stainless steel tote bins conveying 168 pounds of Composition A-7 are unacceptable because of production requirements and equipment constraints. (Author)