Monday, December 10, 2012
Little Boy And Fat Man
These little models came with Monogram's 1/48 scale B 29 Superfortress kit.
"Little Boy" was the codename for the atomic bomb dropped on Hiroshima on August 6, 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul Tibbets of the 393rd Bombardment Squadron, Heavy, of the United States Army Air Forces. It was the first atomic bomb to be used as a weapon. The second, the "Fat Man", was dropped three days later on Nagasaki.
The weapon was developed by the Manhattan Project during World War II. It derived its explosive power from the nuclear fission of uranium 235. The Hiroshima bombing was the second artificial nuclear explosion in history, after the Trinity test, and the first uranium-based detonation. Approximately 600 to 860 milligrams of matter in the bomb was converted into the active energy of heat and radiation (see mass-energy equivalence for detail). It exploded with an energy of 16 kilotons of TNT (67 TJ). It has been estimated that 130,000 to 150,000 people had died as a result of its use by the end of December 1945. Its design was not tested in advance, unlike the more complex plutonium bomb (Fat Man). The available supply of enriched uranium was very small at that time, and it was thought that the simple design of a uranium "gun" type bomb was so sure to work that there was no need to test it at full scale.
"Fat Man" was the codename for the atomic bomb that was detonated over Nagasaki, Japan, by the United States on August 9, 1945. It was the second of two nuclear weapons to be used in warfare to date (the other being "Little Boy"), and its detonation caused the third man-made nuclear explosion. The name also refers more generically to the early nuclear weapon designs of U.S. weapons based on the "Fat Man" model. It was an implosion-type weapon with a plutonium core, similar to "GADGET", the experimental device "detonated only a month earlieron 16 July at Alamagordo Air Base, New Mexico. "Fat Man" was possibly named after Winston Churchill, though Robert Serber said in his memoirs that as the "Fat Man" bomb was round and fat, he named it after Sydney Greenstreet's character of "Kasper Gutman" in The Maltese Falcon.
The original target for the bomb was the city of Kokura, but obscuring clouds necessitated changing course to the alternative target, Nagasaki. "Fat Man" was dropped from the B-29 bomber Bockscar, piloted by Major Charles Sweeney of the 393d Bombardment Squadron, Heavy, and exploded at 11:02 AM (JST), at an altitude of about 1,650 feet (500 m), with a yield of about 21 kilotons of TNT or 88 terajoules. The Mitsubishi-Urakami Ordnance Works, the factory that manufactured the type 91 torpedoes released in the attack on Pearl Harbor, was destroyed in the blast. Because of poor visibility due to cloud cover, the bomb missed its intended detonation point, and damage was somewhat less extensive than that in Hiroshima. An estimated 39,000 people were killed outright by the bombing at Nagasaki, and a further 25,000 were injured. Thousands more died later from related blast and burn injuries, and hundreds more from radiation illnesses from exposure to the bomb's initial radiation. The bombing raid on Nagasaki had the third highest fatality rate in World War II after the nuclear strike on Hiroshima and the March 9/10 1945 Operation Meetinghouse fire bombing raid on Tokyo.
The names for all three atomic bomb design projects during WW II ("Fat Man", "Thin Man", and "Little Boy") were allegedly created by Robert Serber, a former student of Los Alamos director Robert Oppenheimer who worked on the project, according to Serber. According to his later memoirs, he chose them based on their design shapes; the "Thin Man" would be a very long device, and the name came from the Dashiell Hammett detective novel and series of movies by the same name; the "Fat Man" bomb would be round and fat and was named after Sidney Greenstreet's "Kasper Gutman" character in The Maltese Falcon. "Little Boy" would come last and be named only to contrast to the "Thin Man" bomb. The original "Thin Man" had been expected to be as long as 17 feet, but when it was discovered that U-235 would require a slower projectile speed than first measurements had indicated, it was realized that the gun-design could be shortened to 6 feet, and this design was named "Little Boy" in contrast. However, in his memoirs, Paul Tibbets, commander of the 509th Composite Group said the code names were part of an Air Force cover story. According to Tibbets, Project Silverplate, the Air Force program to modify the B-29 to carry atomic bombs, was given the cover story of modifying the B-29 into a passenger plane. One plane was allegedly for the use of Winston Churchill, 'the fat man', and the other for Franklin Roosevelt, 'the thin man.'