"Baker" submerged detonation July 25, 1946. (U. S. Naval Historical Center)
The close of the Second World War ushered in the beginning of the atomic age. The United States was the only nation at the time to successfully develop and produce this devastating weapon, yet it knew very little about the bomb's potential or effects. This initiated an era of nuclear weapons testing that began in 1946 on the remote Pacific islands of Bikini Atoll.
Operation Crossroads was the name given to these naval atomic tests. These tests were designed to show the world that the United States had established nuclear deterrence as part of its defense policy. On July 1, 1946 "Able" and July 25, 1946 "Baker", the world's fourth and fifth nuclear detonations occurred. Now nearly half a century later, over twenty ships from the fleet of Operation Crossroads lie wrecked on the bottom of the lagoon at Bikini Atoll.
Due to it's extremely remote location, large lagoon and small population, Bikini Atoll was selected as the site of these and future nuclear tests. The atoll lies in the Marshall Islands, 4500 miles from San Francisco and 2500 miles from Hawaii.
The "Able" test was designed to duplicate a Hiroshima type air burst attack over a fleet of naval vessels. The bomb named "Gilda" was set to detonate 515 ft above the water in the hopes it would only sink the target ship, USS Nevada. The bomb was dropped from a B-29 flying at 32,000 feet, but unfortunately missed its target by nearly one half a mile and detonated near USS Gilliam. She sank in seventy-nine seconds. Despite the missing the target, "Gilda" sank five ships, rendered another six useless and caused severe damage to eight others.
The "Baker" test was planned as a shallow underwater burst against a battle group lying at anchor. This bomb was named "Helen of Bikini". Encased in a steel caisson made from the conning tower of the USS Salmon, it was suspended ninety feet below the hull of LSM-60, an amphibious landing ship. Upon detonation, a huge fireball turned into a giant mushroom of water and superheated steam. The blast registered on the US west coast as a 5.5 richter scale earthquake. The first shock wave produced a ninety-four foot wave that smashed into USS Saratoga and USS Arkansas.
Although not all the ships sunk by "Baker" went down with the blast, "Helen of Bikini" eventually claimed nine vessels. Most notably were the US aircraft carrier USS Saratoga and the Japanese flag battleship HIMJS Nagato.
The location of the "Ghost Fleet"of Bikini Atoll in their final resting place on the bottom of Bikini's Lagoon. Plotted in the one mile target diameter circle for the "Baker" test. (National Park Service) test.