Proximity Fuze

A proximity fuze is a fuze that is designed to detonate an explosive device automatically when the distance to target becomes smaller than a predetermined value or when the target passes through a given plane. The proximity fuze should not be confused with the common contact fuze.

One of the first practical proximity fuzes was codenamed the VT fuze, an acronym of "Variable Time fuze", as deliberate camouflage for its operating principle. The VT fuze concept in the context of artillery shells originated in the UK with British researchers (particularly Sir Samuel Curran and W. A. S. Butement, whose schematic design for a radar proximity fuze was used with only minor variations) and was developed under the direction of physicist Merle A. Tuve at The Johns Hopkins University Applied Physics Lab (APL). The fuze is considered one of the most important technological innovations of World War II. The Germans were supposedly also working on proximity fuses in the 1930s, research and prototype work at Rheinmetal being halted in 1940 to devote available resources to projects deemed more necessary.