USS Nevada (BB-36), the third United States Navy ship to be named after the 36th state, was the lead ship of the two Nevada-class battleships. Launched in 1914, Nevada was a leap forward in dreadnought technology; four of her new features would be included on almost every subsequent US battleship: triple gun turrets, oil in place of coal for fuel, geared steam turbines for greater range, and the "all or nothing" armor principle. These features made Nevada, alongside her sister ship Oklahoma, the first US Navy "standard-type" battleships.
Operation Crossroads was a pair of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. They were the first nuclear weapon tests since Trinity on July 16, 1945, and the first detonations of nuclear devices since the atomic bombing of Nagasaki on August 9, 1945. The purpose of the tests was to investigate the effect of nuclear weapons on warships.
USS Skate (SS-305) was a Balao-class submarine in service with the United States Navy from 1943 to 1946. She was used as a target ship in the 1946 atomic bomb tests and finally sunk as a target ship in October 1948.
USS Vestal (AR-4) was a repair ship in service with the United States Navy from 1913 to 1946. Before her conversion to a repair ship, she had served as a collier since 1909. Vestal served in both World Wars. She was damaged during the Japanese attack on Pearl Harbor and received two battle stars for her World War II service.
USS Tuna (SS-203) was a United States Navy Tambor-class submarine, serving in the Pacific during World War II and earning seven battle stars for her service. After the war, she participated in the Bikini Atoll atomic testing in 1946.
Shinano was an aircraft carrier built by the Imperial Japanese Navy (IJN) during World War II, the largest such built up to that time. Laid down in May 1940 as the third of the Yamato-class battleships, Shinano's partially complete hull was ordered to be converted to an aircraft carrier following Japan's disastrous loss of four of its original six fleet carriers at the Battle of Midway in mid-1942. The advanced state of her construction prevented her conversion into a fleet carrier, so the IJN decided to convert her into a carrier that supported other carriers.
USS Achomawi (AT-148/ATF-148) was an Abnaki-class fleet ocean tug in the service of the United States Navy, and was named for the Achomawi tribe of Native Americans.
Operation Hardtack I was a series of 35 nuclear tests conducted by the United States from April 28 to August 18 in 1958 at the Pacific Proving Grounds. At the time of testing, the Operation Hardtack I test series included more nuclear detonations than the total of prior nuclear explosions in the Pacific Ocean. These tests followed the Project 58/58A series, which occurred from 1957 December 6 to 1958, March 14, and preceded the Operation Argus series, which took place in 1958 from August 27 to September 6.
USS Gilliam (APA-57), named for Gilliam County in Oregon, was the lead ship in her class of attack transports serving in the United States Navy during World War II.
USS Ottawa (AKA-101) was a Tolland-class attack cargo ship in service with the United States Navy from 1945 to 1947. She was sold into commercial service and was lost in 1951.
Sakawa (酒匂) was the last of four Agano-class light cruisers built for the Imperial Japanese Navy (IJN) during World War II. Fuel shortages crippled the IJN's operations by the time the ship was completed in late 1944 and she never left Japanese waters. After the war, Sakawa was used to ferry Japanese troops home until she was selected in early 1946 to be expended for nuclear weapon tests during Operation Crossroads. The ship was used as a target during the first bomb test on 1 July and sank the following day.
USS LSM-60 was a World War II era landing ship, medium (LSM) amphibious assault ship of the United States Navy. It was notable for being used as the float to suspend a fission bomb underwater during the Operation Crossroads BAKER test, becoming the first naval vessel to deploy a nuclear weapon.
USS Barrow (APA-61) was a Gilliam class attack transport serving in the United States Navy from 1944 to 1946. She was scuttled in 1948.
USS Phaon (ARB-3) was planned as a United States Navy LST-1-class tank landing ship, but was redesignated as one of twelve Aristaeus-class battle damage repair ships built for the United States Navy during World War II. Named for Phaon, she was the only US Naval vessel to bear the name.
Operation Sailor Hat was a series of explosives effects tests, conducted by the United States Navy Bureau of Ships under the sponsorship of the Defense Atomic Support Agency. The tests consisted of two underwater explosions at San Clemente Island, California in 1964 and three surface explosions at Kahoʻolawe, Hawaii in 1965. They were non-nuclear tests employing large quantities of conventional explosives to determine the effects of a nuclear weapon blast on naval vessels, and the first major test of this kind since Operation Crossroads in July 1946.
The PS Washington Irving was a 4,000-short-ton (3,600 t) sidewheel day boat and the flagship of the Hudson River Day Line that operated on the Hudson River from 1913 to 1926.
Nuclear testing at Bikini Atoll consisted of the detonation of 23 nuclear weapons by the United States between 1946 and 1958 on Bikini Atoll in the Marshall Islands. Tests occurred at 7 test sites on the reef itself, on the sea, in the air, and underwater. The test weapons produced a combined yield of about 77 Mt of TNT in explosive power. After the inhabitants agreed to a temporary evacuation, to allow nuclear testing on Bikini, which they were told was of great importance to humankind, two nuclear weapons were detonated in 1946. About ten years later, additional tests with thermonuclear weapons in the late 1950s were also conducted. The first thermonuclear explosion was much more powerful than expected, and created a number of issues, but did demonstrate the dangers of such devices.
The Type B ship is a United States Maritime Administration (MARAD) designation for World War II barges. Barges are very low cost to build, operate and move. Barges were needed to move large bulky cargo. A tug boat, some classed as Type V ships, could move a barge, then depart and move on to the next task. That meant the barge did not have to be rushed to be unloaded or loaded. Toward the end of World War 2, some ships that had not been completed in time for the war were converted to barges. US Navy barges are given the prefix: YWN or YW. Due to shortage of steel during World War II, concrete ship constructors were given contracts to build concrete barges, with ferrocement and given the prefix YO, YOG, YOGN. Built in 1944 and 1945, some were named after chemical elements.
The ARDC-13 was a 2800-ton auxiliary floating drydock used for testing during the Able and Baker nuclear weapon tests of Operation Crossroads in the Bikini Atoll. It was used to determine the effects of the atomic bomb phenomena on land-based concrete structures. The final report on ARDC-13 was part of a final supplementary report to the Commander Joint Task Force One. The ARDC-13 was built by the Haddock Company of Pasadena, California, in March 1946 under contract Noy-11999. It was 84 feet by 389 feet with a depth of 14 feet. Two wingwalls, both 26 feet high and 306 feet long, were mounted on top of the ARDC-13. Steel frames were built within the wingwalls for extra support. The wingwalls consisted of transverse frames and both water and non-watertight bulkheads. The ARDC-13 was important for confirming that water-front structures needed to be designed to withstand severe waves and flooding as ports are considered a good target for bombs.
The YOG-83 was a gasoline barge built in January 1944 by the Concrete Ship Constructors of National City California for the Maritime Commission. It was in service as a gasoline barge in the Pacific before being moved and used during nuclear weapon testing. The testing was part of Operation Crossroads at Bikini Atoll. It was 375 feet (114 m) long with a displacement rated at 10,960 tons. It was noted that the barge had incurred slight damage from general use during its service as a gasoline barge, but the damage was not significant and would not effect how the bomb testings would be rated.
