Able and Baker atomic tests at Bikini
Operation Crossroads was an atmospheric nuclear weapon test series conducted in the summer of 1946 at Bikini Atoll in the Marshall Islands. The series consisted of two detonations, a low altitude test and a shallow water test. The devices, each with a yield of 21 kilotons, were named shots ABLE and BAKER. A planned third test, a deep underwater detonation, was canceled after the second test.
Operation Crossroads was a series of nuclear weapon tests conducted by the United States at Bikini Atoll in the summer of 1946. Its purpose was to test the effect of nuclear weapons on naval ships. The series consisted of two detonations, each with a yield of 23 kilotons:[1] Able was detonated at an altitude of 520 feet (158 m) on July 1, 1946; Baker was detonated 90 feet (27 m) underwater on July 25, 1946. A third burst, Charlie, planned for 1947, was canceled primarily because of the Navy's inability to decontaminate the target ships after the Baker test.
New York prepared at Pearl Harbor for the planned invasion of Japan, and after war's end, made a voyage to the West Coast returning veterans and bringing out their replacements. She sailed from Pearl Harbor again on 29 September with passengers for New York, arriving on 19 October. Here she prepared to serve as target ship in Operation Crossroads, the Bikini atomic tests, sailing on 4 March 1946 for the West Coast. She left San Francisco on 1 May, and after calls in Pearl Harbor and Kwajalein, reached Bikini on 15 June. Surviving the surface blast on 1 July and the underwater explosion on 25 July, she was taken into Kwajalein and decommissioned there on 29 August. Later towed to Pearl Harbor, she was studied during the next two years, and on 8 July 1948 was towed out to sea some 40 mi (35 nmi; 64 km) and there sunk after an 8-hour pounding by ships and planes carrying out full-scale battle maneuvers with new weapons. An article in Naval Aviation News (October 1948) described the weapons exercise that USS New York was subjected to:
"The ex-BB's New York and Nevada, having survived the tests at Bikini, were towed from Pearl Harbor to a spot south of Oahu, and there were subjected to an unmerciful pounding by fleet air and surface units. Planes led by the commanding officer of Fleet All Weather Training Unit Pacific (FAWTUPAC), Captain Paul H. Ramsey, USN, were in on both kills. On 7 July 1948 the New York was the first to feel the sting of the fighters and attack aircraft. Twenty-six planes, consisting of two F7F-4Ns, six F8F-1Ns, twelve F6F-5Ns, and six TBM-3Ns dropped a total of 48 500-pound bombs, 40 100-pound bombs, 98 5-inch HVARs and expended 4,100 rounds of .50 caliber ammunition. Twenty-one direct hits were scored with the 500-pound bombs, 20 direct hits were scored with the 100-pound bombs, and 56 direct hits were scored with the 5-inch HVARs. While surface units stood by and submarines waited to close in for the kill, the tired old battlewagon rolled over and sank as the last participating FAWTUPAC planes recovered from their bombing attacks."[3]
http://en.wikipedia.org/wiki/USS_New_York_(BB-34)
us naval history site has info on BB class ships