By 1957, in the early and dangerous days of the Cold War, the only two powers who had acquired thermonuclear weapons were the Soviet Union and the United States. The UK was a nuclear power, having detonated an atomic bomb in 1952, but it was behind the others powers in technology. That changed in 1957, when the UK conducted nine nuclear tests under the name Operation Grapple, and joined the thermonuclear (or hydrogen) club as the third member.
Britain's attempts to acquire nuclear weapons began during the Second World War, when many British scientists contributed to the Manhattan Project, which developed the first nuclear weapons for the United States. Resuming its own atomic program after the war, the UK moved slower than the other powers, partly because the 'Special Relationship' between the UK and the US did not originally extend to the nuclear sphere.
The first test of their own hydrogen bomb, shown above, was initially hailed as a great success but was in fact a technical failure as the explosion was well below its designed capability. Nevertheless the UK continued with its research and conducted the last test in 1958, confirming its status as a hydrogen power.
Several countries have since also developed weapons of mass destruction, while the UK is estimated to have around 215 nuclear warheads.
Source: Wikimedia Commons
- 1957-05-15 Operation Grapple: Britain tests its first hydrogen bomb near Christmas Island in the Indian Ocean