Operation Totem status, the British government restarted its own development effort, which was given the cover name "High Explosive Research". The first British atomic bomb was tested in Operation Hurricane at the Montebello Islands in Western Australia on 3 October 1952. The main purpose of the trial was to determine the acceptable limit on the amount of plutonium-240 which could be present in a bomb. The plutonium used in the original Hurricane device was produced in the nuclear reactor at Windscale, but the Windscale Piles did not have anything like the capacity to provide sufficient material for the British government's planned weapons
Radar, Anti-Aircraft No. 3 Mk. 7 ten years off suggested no major production should take place, as developments in the interim would render any radars built in that period obsolete. However, various events in 1949, notably the first Soviet atomic test, led to sweeping upgrades, including the first contract for production Mk. 7's. These began to arrive in 1952. The Swiss Air Force received twelve Mk. 7's in 1958, which they referred to as Feuerleitradar ("fire control radar") Mark VII. They combined them with their own predictor, the Hasler-built "Kommandogerät" ("command device") 43/50R. Like its British counterpart, the 43/50R could be fed information directly from the