Operation Hurricane

Operation Hurricane was the test of the first British atomic bomb on 3 October 1952.
A plutonium implosion type bomb was used in the test.
The weapon was a close copy of the Fat Man (Nagasaki) weapon,To test the effects of a ship-smuggled bomb (a threat of great concern to the British at the time), Hurricane was exploded inside the hull of HMS Plym.The device exploded with a force of 25kt.