A Test in History: Nuclear Fallout at Bikini Atoll

The Dawn of the Atomic Age

From 1945 through 1954, the United States conducted a series of tests to determine the effect of nuclear weapons. Trinity was the first test in the series, held July 16, 1945 on what is now called the White Sands Missile Range. It was designed to test the implosion-design plutonium bomb. This event is attributed with being the start of the Atomic Age.

Following the Tinity test, the United States dropped the atomic bomb, code-named Little Boy, on Hiroshima, Japan on August 6, 1945. Three days later, the Fat Man bomb was dropped on Nagasaki. These were the first atomic bombs to be used as weapons of war.

Above is a picture of the Fat Man bomb which weighed 10,200 lbs. with a length of 10.6 ft. and a diameter of 5 feet. The blast yielded from this bomb equaled 21 kilotons of TNT.

Operation Crossroads

In the summer of 1946, a series of three tests were to take place at Bikini Atoll in the Marshall Islands. The purpose of these tests was to determine the effect of nuclear bombs on naval ships. This series of tests was named Operation Crossroads.

Test Able

The first test, Able, was performed on July 1, 1946. There were 114 people from the press present to observe the test. They were disappointed, however, with the test results and lack of carnage to the ships. They were unaware at the time, that the bomb had missed its target by 710 yards.

Test Baker

On July 25, 1946, the second test in the series, test Baker was performed. Unlike all preceding nuclear detonations that had been shot as air burst, Baker was suspended beneath the landing craft and detonated 90 feet underwater.

Baker generated an underwater fireball which expanded into hot gas bubbles producing a supersonic, hydraulic shock wave which crushed ship hulls in the surrounding area. The shock wave appeared as a ring of dark water followed by a whitening of the water surface. These were referred to as the slick and the crack.

The gas bubble hit the sea floor and surface simultaneously digging a crater in the seabed while creating a geyser-like spray dome at the surface.

The Wilson cloud, seen above is actually a condensation cloud and is one of the most famous photograph’s of the Baker test.