Early history of the proximity fuze (1937–1940)

Abstract

The RAF's air exercises of 1936/37 highlighted the inability of Fighter Command's force of obsolete biplane fighters to intercept modern, fast, monoplane bombers. One tactic suggested to counter this deficiency was known as ‘bombing the bomber’. The idea advanced was that fighters should drop bombs, on an enemy's bombers, which would explode in their midst. Essentially the proposal depended on the conversion of the bomb's potential energy into kinetic energy in order to gain a temporary advantage in speed. Contact-fuzed and time-fuzed bombs were inappropriate for this purpose and so it seemed worth endeavouring to develop a fuze which would detonate automatically when the bomb passed near to a target. Both acoustic and photo electric proximity fuzes were produced and demonstrated before the outbreak of the Second World War, although the early reliability of the photoelectric fuze was unsatisfactory and both fuzes had inherent limitations. Several applications of the PE proximity fuze were advanced and partially developed in 1939–40. These included the use of the fuze in UPs (unrotated projectiles), in ground-influenced bombs, in an airfield defence scheme for protecting airfields against low flying aircraft and as a means of defending bombers against stern fighter attacks. The paper considers the early history of the origin, development, potential applications, and limitations of some British proximity fuzes (principally the PEPF) and of their subsequent replacement by the radio proximity fuze.