In the summer of 1946, just a year after World War II ended, the U.S. Navy conducted two atmospheric nuclear bomb tests at (the name would be immortalized in the two-piece bikini swimsuit). Here, the United States learned horrifying lessons about the newest weapon to enter its arsenal, confirming nukes as truly the worst weapon ever devised.
The tests were dubbed , and the purpose to determine the effectiveness of nuclear bombs against navy ships. Ninety-five obsolete and decommissioned navy ships, including four battleships, two aircraft carriers, two cruisers, and dozens of destroyers, replenishment ships, amphibious ships, and even captured German and Japanese navy ships were towed to the middle of Bikini Atoll to simulate a fleet at anchorage. Around 42,000 U.S. military personnel were on hand to support the exercise. Animals were seeded among the ships to study the effects of the bomb on living things, and so 200 pigs, 60 guinea pigs, 204 goats, 5,000 rats, and 200 mice were placed in cages above and below decks.
Then the U.S. Navy, cameras rolling, dropped the first bomb. The bomb, nicknamed "Able" by the Navy, was a plutonium-fuel nuclear bomb, the same as used at Nagasaki, Japan. It had an explosive yield of 23 kilotons, or 23,000 tons of TNT, and was dropped from a B-29 bomber and detonated at an altitude of 520 feet.
The results were almost underwhelming, if you can believe it. Only five ships were sunk, the largest being a Japanese cruiser. Radioactivity, which was measured at lethal levels inside the ship, quickly dissipated and the ships were capable of being safely boarded within days. The test proved that while crews on navy ships were vulnerable to radiation and that nuclear weapons could render them "ghost ships," the ships themselves retained little residual radiation and could be remanned.
The second bomb, Baker, was detonated 90 feet under a navy ship moored in the atoll. No trace of that ship was ever found. The explosion produced a tremendous dome-shaped cloud of water vapor, releasing a supersonic shockwave moving through the water that hit ships like a sledgehammer. This time eight ships were sunk, including two battleships and an aircraft carrier.
The real damage came from the radiation. In addition to a blast of lethal radiation similar to the Able test, the remaining ships were showered with radioactive water and debris that proved impractical to decontaminate. Ships had to be stripped to bare metal to remove radiation, and crews assigned to clean them became contaminated themselves. After being studied the ships were scuttled, too dangerous to use again.
The U.S. Navy was caught unprepared by the level of near-permanent dangerous radioactivity unleashed by the Baker test. The Hiroshima and Nagasaki bombs, like Able, were air-dropped and exploded above ground. So-called "" explosions generate little fallout, which explains why Hiroshima was rebuilt and people can still live there today. Ground or underground/underwater explosions like Baker, on the other hand, throw up large, lethal clouds of radioactive water vapor, dirt, or debris—AKA fallout—that can be carried downwind.
The Able and Baker tests showed the world that nukes were more frightening than previously imagined, creating widespread, invisible dangers that could linger for generations. While the tests—particularly the use of animal test subjects—were horrific, they likely contributed to the growing stigma against the use of nuclear weapons.