Little Boy Bomb Casing
"Little Boy" was the codename for the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul W Tibbets, Jr., commander of the 509th Composite Group of the US Army Air Forces. It was the first atomic bomb to be used in warfare.
The Hiroshima bombing was the second artificial nuclear explosion in history, after the Trinity test, and the first detonation using uranium as its fuel; the design was considered so fundamentally sound that it was not tested before delivery. It exploded with an energy of approximately 15 kilotons of TNT, causing significant destruction to the city of Hiroshima.
Little Boy was developed by Lieutenant Commander Francis Birch's group of Captain William S Parsons's Ordnance (O) Division at the Manhattan Project's Los Alamos Laboratory during World War II. Parsons flew on the Hiroshima mission as weaponeer. The Little Boy was a development of the unsuccessful Thin Man nuclear bomb. Like Thin Man, it was a gun-type fission weapon, but derived its explosive power from the nuclear fission of U-235. This was accomplished by shooting a hollowed-out block of enriched uranium onto a solid cylinder of the same material by means of a charge of nitrocellulose propellant powder (blog.nuclearsecrecy.com/2011/11/08/the-mysterious-design-...). It contained 64 kg of enriched uranium, of which less than a kilogram underwent nuclear fission (so in technical terms could be considered quite inefficient!). Its components were fabricated at three different plants so that no one would have a copy of the complete design.
After the war ended, it was not expected that the Little Boy design would ever again be required, and many plans and diagrams were destroyed, but by mid-1946 the Hanford Site plutonium-production reactors were suffering technical problems, 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 All the Little Boy units were withdrawn from service by the end of January 1951.
The above casing, one of six still surviving, has been loaned by the US government to the Imperial War Museum in London, where it is seen at the entrance to their Peace and Security exhibit.
Little Boy Bomb Casing
"Little Boy" was the codename for the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul W Tibbets, Jr., commander of the 509th Composite Group of the US Army Air Forces. It was the first atomic bomb to be used in warfare.
The Hiroshima bombing was the second artificial nuclear explosion in history, after the Trinity test, and the first detonation using uranium as its fuel; the design was considered so fundamentally sound that it was not tested before delivery. It exploded with an energy of approximately 15 kilotons of TNT, causing significant destruction to the city of Hiroshima.
Little Boy was developed by Lieutenant Commander Francis Birch's group of Captain William S Parsons's Ordnance (O) Division at the Manhattan Project's Los Alamos Laboratory during World War II. Parsons flew on the Hiroshima mission as weaponeer. The Little Boy was a development of the unsuccessful Thin Man nuclear bomb. Like Thin Man, it was a gun-type fission weapon, but derived its explosive power from the nuclear fission of U-235. This was accomplished by shooting a hollowed-out block of enriched uranium onto a solid cylinder of the same material by means of a charge of nitrocellulose propellant powder (blog.nuclearsecrecy.com/2011/11/08/the-mysterious-design-...). It contained 64 kg of enriched uranium, of which less than a kilogram underwent nuclear fission (so in technical terms could be considered quite inefficient!). Its components were fabricated at three different plants so that no one would have a copy of the complete design.
After the war ended, it was not expected that the Little Boy design would ever again be required, and many plans and diagrams were destroyed, but by mid-1946 the Hanford Site plutonium-production reactors were suffering technical problems, 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.
The above casing, one of six still surviving, has been loaned by the US government to the Imperial War Museum in London, where it is seen at the entrance to their Peace and Security exhibit.