Seventy years ago this month a joint U.S Army-Navy task force staged two atomic weapons tests at Bikini Atoll in the Marshall Islands, the first atomic explosions since the bombings of Japan in August 1945. The first test, Able, took place on 1 July 1946. The second test, Baker, on 25 July 1946, was the most dangerous, contaminating nearby ships with radioactive fallout and producing iconic images of nuclear explosions later used in Stanley Kubrick’s Dr. Strangelove. Documents posted today by the National Security Archive, shed light on Operation Crossroads, as does a gallery of videos and photographs.
The Navy, worried about its survival in an atomic war, sought the Bikini tests in order to measure the effects of atomic explosions on warships and other military targets. Named Operation Crossroads by the task force’s director, Rear Admiral William Blandy, the tests involved a fleet of 96 target ships, including captured Japanese and German warships. Both tests gave the U.S. military what it sought: more immediate knowledge of the deadly effects of nuclear weapons.
The U.S. Navy’s early March 1946 removal of 167 Pacific islanders from Bikini, their ancestral home, so that the Navy and the Army could prepare for the tests, is also documented with film footage. The Bikinians received the impression that the relocation would be temporary, but subsequent nuclear testing in the atoll rendered the islands virtually uninhabitable.
Observers from the United Nations Atomic Energy Commission, including two from the Soviet Union, viewed the Crossroads tests from a safe distance. Recently declassified documents shed light on the emerging Cold War atmosphere; one of the observers, Simon Peter Alexandrov, who was in charge of uranium for the Soviet nuclear project, told a U.S. scientist, Paul S. Galtsoff, that while the purpose of the Bikini test was “to frighten the Soviets,” they were “not afraid,” and that the Soviet Union had “wonderful planes” which could easily bomb U.S. cities.
Today’s posting contains a number of primary source documents on the planning of Operation Crossroads and assessments of the two tests, including:
- An estimate from Los Alamos Laboratory of the planned underwater atomic test: “There will probably be enough plutonium near the surface to poison the combined armed forces of the United States at their highest wartime strength.”
- A report by an Army officer on the Able test, which exploded in mid-air above an array of warships, conveyed Army-Navy tensions: Noting that Admiral Blandy had painted a “very optimistic picture from the Navy point of view” of the damage done to the ships, “when we examined the target fleet through our field glasses [we saw] that even on the major capital ship, superstructures had been severely damaged.” “The target fleet had indeed suffered a staggering blow.”
- The Joint Chiefs of Staff (JCS) Evaluation Board noted in a message sent after the Baker test that because of the radioactive water the Baker test spewed upon the ships, the “contaminated ships became radioactive stoves, and would have burned all living things aboard with invisible and painless but deadly radiation.”
- According to a Navy observer’s report, the two tests were “spectacular and awe-inspiring,” but the “radiological contamination of the target vessels which followed the underwater burst was the most startling and threatening aspect.”
- The contamination of the target ships caused by the Baker test led Stafford Warren, the task force’s radiation safety adviser, to warn Admiral Blandy of the danger of continuing decontamination work to salvage the ships: the ships were “in the main extensively contaminated with dangerous amounts of radioactivity.” It was not possible to achieve “quick decontamination without exposing personnel seriously to radiation.” These warnings eventually led Blandy to halt the cleanup effort.
- The Joint Chiefs of Staff Evaluation Board’s final report on the Crossroads tests called for U.S. superiority in atomic weaponry and Congressional action to give the U.S. Presidents license to wage preventive war against adversaries which were acquiring nuclear weapons. The Crossroads report was suppressed for years until it was declassified in 1975.