Operation Grapple with the American Manhattan Project in August 1943. Many of Britain's top scientists participated in the British contribution to the Manhattan Project. After the war, fearing that Britain would lose its great power status, the British government resumed the atomic bomb development effort, now codenamed High Explosive Research. The successful test of an atomic bomb in Operation Hurricane in October 1952 represented an extraordinary scientific and technological achievement, but Britain was still several years behind the United States in nuclear weapons technology. In July 1954, the Cabinet decided to develop the hydrogen bomb. The United Kingdom Atomic Energy Authority Atomic
Crack in the World atomic device is used and Rampion's fears prove justified, as the crust of the Earth develops an enormous crack that progresses rapidly. Sorenson discovers that there was a huge reservoir of hydrogen underground, which turned the small conventional atomic explosion into a huge thermonuclear one that was millions of times more powerful. Another atomic device, lowered into the magma chamber of an island volcano, is used in the hope of stopping the crack, but it only reverses the crack's direction. Eventually the crack returns to its starting point at the test site, and a huge chunk of the planet outlined