The first peacetime nuclear tests, conducted at Bikini in 1946 in a
military-scientific exercise designated Operation Crossroads, were
designed to assess the effects of nuclear weapons on naval vessels. The
test organization, Joint Task Force One, an adaptation of the wartime
joint task force combat concept, was a massive waterborne force
including 42,000 members of the armed services, civilian scientists,
consultants, and observers.
[Illustration: _The Bikini Lagoon before testing._]
Bikini Atoll was selected for the tests because, among other things, it
was remote from heavily populated areas, it offered a protected
anchorage, and it had the relatively stable and predictable
meteorological and oceanographic conditions considered essential to
operations in which the unknowns loomed so large. Three test detonations
originally were projected; two ultimately were carried out. The first,
Test Able, was an airdrop of an atomic bomb on July 1, 1946, over a test
fleet of 70 ships anchored in Bikini Lagoon. The second, Test Baker, was
the detonation on July 25 of an atomic device suspended in the lagoon 90
feet below a small target vessel.