#AceHistory2Research – Operation Crossroads was a series of two nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946 to investigate the effect of such weapons on naval ships.
They were the first nuclear detonations after World War II, and the first ever to be publicly announced beforehand and observed by an invited audience, including a large press corps.
A fleet of 95 target ships was assembled in Bikini Lagoon and hit with two detonations of Fat Man plutonium implosion-type nuclear weapons of the type dropped on Nagasaki, each with a yield of 23 kt (96 TJ).
The first test, Able, was an air burst that sank five ships and demonstrated the survivability of ships located more than 1 kilometre (0.62 mi) from the explosion.
The second test, Baker, was an underwater explosion, which effectively destroyed the entire target fleet with radioactive contamination. It was the first case of immediate, concentrated radioactive fallout from a nuclear explosion.
The fallout from Baker and subsequent Bikini tests still renders the area uninhabitable. Glenn Seaborg, the longest-serving chairman of the U.S. Atomic Energy Commission, called Baker “the world’s first nuclear disaster.”