Explosion waves and shock waves V—The shock wave and explosion products from detonating solid explosives

Abstract

The methods described in Parts I and II of this series of papers (Payman and Woodhead 1931; Payman, Titman and Woodhead 1935) have been used to obtain photographic records of the atmospheric disturbance produced on detonating a cartridge of explosive when it is freely suspended in air, and at the same time to gain some knowledge of the mode of breakdown of the cartridge during detonation. We have used two coal-mining explosives, Rounkol No. 2, a “low-density” explosive containing ammonium nitrate together with a mixture of nitroglycerine and nitroglycol, and Celmonite, an explosive of normal density of the ammonium nitrate class containing no nitroglycerine. The published compositions of these explosives (parts by weight) are as follows: Rounkol No. 2 Celmonite Nitroglycerine and nitroglycol 14-16 — Ammonium nitrate 49-52 65·5-68·5 Trinitrotoluene — 10·5-12·5 Sodium nitrate 8·5-10·5 — Sodium chloride 6-8 19·5-21·5 Plant fibre 15-17 — Resin 0-0·5 — Di-ammonium phosphate 0-0·5 — Moisture 0·5-2·5 0-2 These explosives have the same weight strength as measured by a ballistic pendulum. Their densities were: Rounkol No. 2 0·66 and Cel­monite 1·10; and their rates of detonation Rounkol No. 2 2090 and Celmonite 2950 m./sec. Each explosive was used in cartridges 1 7/16 in. (3·65 cm.) in diameter, wrapped with paper and waxed except when other­wise indicated. No. 6 copper-cased fulminate-chlorate detonators, elec­trically fired, were used for initiation.