A huge blast and a cloud of danger, Britain gets the bomb
Britain carried out its first atomic bomb test in October 1952 to become the world’s third nuclear power after the United States and the Soviet Union.
Unlike the US bombing of Hiroshima and Nagasaki in 1945, Britain’s first nuclear bomb was not dropped from a plane.
The bomb was exploded inside the hull of frigate HMS Plym. The 25-kiloton atom bomb was detonated a few seconds before 9.30am on October 3, 1952 approximately 1,300ft from the island of Trimouille in the Monte Bello Islands, Western Australia.
According to eyewitnesses, Plym was reduced to a “gluey black substance” that washed up on shore. The explosion left a crater, 20ft deep and 980ft wide on the seabed.
After the detonation, the Montebello Islands remained a prohibited area until 1992. The fallout cloud, which rose to 10,000ft, was blown out to sea as planned but the wind later reversed direction and blew back over the Australian mainland.
Very low levels of radioactivity were detected as far away as Brisbane. By the 1980s the radioactivity on the islands had diminished to the point where it was no longer dangerous to visitors.
However, the area still contains radioactive metal fragments – the remains of Plym – containing cobalt-60.
Now the area is a park with a pyramid-shaped obelisk marking the blast site. Even 70 years after the event, visitors are warned not to spend more than an hour a day at the test sites or to take any relics as souvenirs.