Detonation in Liquid Explosives

Abstract

DURING the War a general investigation was commenced at the Road Research Laboratory, on the initiative of Dr. A. H. Davis, into the process of detonation in explosives, the programme including a photographic study of the detonation Waves in transparent liquid explosives—the sensitivity of some of which can be varied by adjusting the constitution—and their relation to primers of different types and shapes. In the Work, use was made of a new highspeed mirror camera to photograph the progress of the luminous detonation front inside transparent liquid explosives. A unique feature of the camera was the employment of two independent lens assemblies, each consisting of a telephoto field component focusing on to a spectrographic slit. The slits themselves were focused, via a four-sided rotating mirror, on to a photographic film located in cylindrical guides. The fields of the two slits were arranged to intersect at right angles in the object plane, approximately 30 ft. from the camera. Further, by means of a suitable arrangement of plane mirrors between the rear lenses and the film, images from the two slits were arranged to record on different areas of the same film. Use was made in this connexion of adjacent sides of the mirror block. In this manner it was possible to record simultaneously in two directions at right angles. The maximum recording speed was approximately 100 cm. per sec., with a time resolution of 1 microsecond.