Weight: 10,800 lbs Length: 10 ft 8 in.; Diameter: 60 in "Fat Man" was the second plutonium, implosion-type bomb. The first was the "Gadget" detonated at the Trinity site on July 16, 1945. In the implosion-type device, a core of sub-critical plutonium is surrounded by several thousand pounds of high-explosive designed in such a way that the explosive force of the HE is directed inwards thereby crushing the plutonium core into a super-critical state. Dropped on the Japanese city of Nagasaki on August 9, 1945, it was the second nuclear weapon used in a war.
How many more bombs were produced after?
Two more Fat Man bombs were detonated during the Operation Crossroads nuclear tests at Bikini Atoll in 1946. Some 120 Fat Man units were produced between 1947 and 1949, when it was superseded by the Mark 4 nuclear bomb. The Fat Man was retired in 1950.
After the war ended, it was not expected that the inefficient Little Boy design would ever again be required, and many plans and diagrams were destroyed, but by mid-1946 the Hanford Site reactors were suffering badly from the Wigner effect, so six Little Boy assemblies were produced at Sandia Base. The Navy Bureau of Ordnance built another 25 Little Boy assemblies in 1947 for use by the Lockheed P2V Neptune nuclear strike aircraft (which could be launched from but not land on the Midway-class aircraft carriers). All the Little Boy units were withdrawn from service by the end of January 1951
What were the long term effects of the atomic bomb?