This was accomplished by shooting a hollow cylinder of uranium over another hollow enriched uranium cylinder by means of four silk bags of cordite powder. Like Thin Man, it was a gun-type fission weapon, but derived its explosive power from the nuclear fission of uranium-235. The Little Boy was a development of the unsuccessful Thin man nuclear bomb. Parsons flew on the Hiroshima mission as weaponeer. Parsons's Ordnance (O) Division at the Manhattan Project's Los Alamos Laboratory during World War II. Little Boy was developed by Lieutenant Commander Francis Birch's group of Captain William S. It exploded with an energy of 16 kilotons of TNT (67 TJ). Approximately 600 to 860 milligrams (9.3 to 13.3 grains) of matter in the bomb was converted into the energy of heat and radiation. The Hiroshima bombing was the second artificial nuclear explosion in history, after the Trinity test, and the first uranium-based detonation. It was the first atomic bomb to be used as a weapon. Tibbets, Jr., commander of the 509th Composite Group of the United States Army Air Forces. Find out more about the authors who wrote them.Little Boy was the codename for the type of atomic bomb dropped on Hiroshima on Augby the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul W. The fact files in this timeline were commissioned by the BBC in June 2003 and September 2005. It was the first time his voice had been heard on the radio.Īfter the war, Hiroshima was rebuilt as a peace memorial city and the closest surviving building to the epicentre was designated the Hiroshima Peace Memorial. At midday on the following day, Emperor Hirohito broadcast the news to the Japanese people. On 14 August, Japan agreed to the Allies' terms of surrender. 'Obscene in its greedy clawing at the earth, swelling as if with its regurgitation of all the life that it had consumed.' He later recalled the cloud caused by the atomic blast in Martin Gilbert's Second World War: The final death toll was calculated as at least 50,000.Īmong those in the plane that dropped the bomb on Nagasaki was the British pilot Leonard Cheshire. About 40,000 people were killed instantly and a third of the city was destroyed. The original target was Kokura, but this was obscured by cloud so the bomb was dropped on nearby Nagasaki, an important port. On the morning of 9 August, the Americans dropped a second, bigger atomic bomb.
In addition, it may also have been a way of demonstrating American military superiority over the Soviet Union. The Allies feared that any conventional attempt to invade the Japanese home islands would result in enormous casualties, and the bomb was seen as a way of bringing the war against Japan to a swift conclusion. Hiroshima was chosen because it had not been targeted during the US Air Force's conventional bombing raids on Japan, and was therefore regarded as being a suitable place to test the effects of an atomic bomb.
Thousands of people were made homeless and fled the devastated city. And the intense heat of the explosion then created many fires, which consumed Hiroshima and lasted for three days, trapping and killing many of the survivors of the initial blast.
The blast destroyed more than ten square kilometres (six square miles) of the city. As well as residents of Hiroshima, the victims included Koreans who had been forced to come to Japan as labourers, and American prisoners-of-war who were imprisoned in Hiroshima. The final death toll was calculated at 135,000. Many more died of the long-term effects of radiation sickness. The heat from the bomb was so intense that some people simply vanished in the explosion. Between 60,000 and 80,000 people were killed instantly. The bomb was dropped by parachute and exploded 580m (1,900ft) above the ground.
On the morning of 6 August 1945 an American B-29 bomber, the 'Enola Gay', dropped the first atomic bomb used in warfare on the Japanese city of Hiroshima.