Operation Crossroads was the code name given to a series of nuclear weapons tests at Bikini Atoll in the Pacific in July 1946. The tests carried out by Joint Task Force 1, a combined Army and Navy operation. The stated purpose of the tests was to observe the effects of nuclear weapons on naval vessels.
Unlike the Trinity tests in the desert of New Mexico, Operation Crossroads was a very public affair. Invited guests included a large media presence, scientists and foreign military observers.
Three tests were planned. Test Able was was an air burst of a 23 kiloton “fat boy”. Test Baker involved an underwater detonation of a similar device. Test Charlie was to have a deep water detonation. Problems with decontaminating the test ships after Test Baker prevented Rest Charlie from occurring.
A fleet of seventy-one vessels was assembled in the Bikini lagoon as the target array. The ships were mostly American vessels including the carriers Independence and Saratoga and the battleships Arkansas, Nevada, New York and Pennsylvania. A few captured German and Japanese ships were also included.
Test Able was conducted on July 1, 1946. The bomb was dropped from a B-29 of the 509th Bomb Group. The bomb missed the target vessel, USS Nevada, by 750 yards. Five ships were sunk immediately and fourteen others badly damaged. The media was underwhelmed by the damage. The scientific evidence showed that the crew on most of the vessels would have perished from the effect of the radiation.
Test Baker took place on July 25, 1946. The device was detonated ninety feet below the surface suspended from LSM-60. While the plume from Test Able took most of the radioactive material into the stratosphere, the underwater detonation of Test Baker caused a radioactive soup to inundate the target vessels. The contamination was so bad that decontamination of most of the ships was abandoned and the vessels sunk.
The operation required the displacement of 167 natives from Bikini. Poor fishing conditions in their new home required their removal once more. Seventy-three years later Bikini Atoll remains uninhabited.
A number of numismatic items exist from Operation Crossroads. At least three different souvenir notes were printed for use as short snorters and there are chits from the recreation facilities on Kwajalein.
The first short snorter was made by the 58th Bomb Squadron of the 509th Bomb Group. The B-29 that dropped the bomb for Test Able was from the 58th Bomb Squadron.
The second type was printed by the Navy for JTF-1.
The third short snorter was printed for use on the USS Sumner. The Sumner was a survey vessel that conducted the preparatory work in the Bikini lagoon before the tests.
The Coral Reef Tavern was the name of the Navy run recreation facility on Kwajalein. Five and ten cent chits for use in the Coral Reef Tavern have survived.
Operation Crossroads also has a large philatelic footprint. Commemorative covers were made for most, if not all, of the target vessels as well as many of the support ships. The 58th Bomb Wing also made a commemorative cover that was carried on the plane that dropped the bomb for Test Able carrying a July 1, 1946 postmark.