The choice of plutonium for the fissile component of the bomb meant that Penney 's HER team at Fort Halstead had to design an implosion-type nuclear weapon . The Los Alamos Laboratory had solved the problem of doing this with explosive lenses . The involvement of several British scientists gave HER a solid base of experience to work from . The British design would hew to that of the American Fat Man as closely as possible . An important change would be the substitution of RDX , an ARD product , for Composition B as the fast explosive component of the lenses ; Baratol would still provide the slow component . This was handled by the explosives experts at Woolwich , who devised the machining processes and produced prototypes of the lenses and moulds . Production was then handled by two Royal Ordnance Factories . The first lenses were delivered in 1952 , and there were enough for two sets for the Operation Hurricane assemblies . Woolwich provided the supercharge , the spherical shell of explosive that encases the tamper . Test firings of explosive lenses were conducted at Foulness by a team under the direction of Roy Pilgrim . To achieve near-simultaneous detonations of the lenses , the Americans had developed the exploding-bridgewire detonator ; this had to be duplicated . Ernest Mott and Cecil Bean developed them , while Challens devised the firing circuits
Operation Hurricane
Operation Hurricane
High Explosive Research