"Fat Man" (also known as Mark III) was the design of the nuclear weapon the United States used for seven of the first eight nuclear weapons ever detonated in history. A Fat Man device was detonated over the Japanese city of Nagasaki on 9 August 1945. It was the second and largest of the only two nuclear weapons ever used in warfare.

“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 ...

2023年11月7日 · Little Boy was a gun-type nuclear bomb deployed over Hiroshima, while Fat Man was an implosion-type bomb deployed over Nagasaki. We are eagerly awaiting the 2023 release of Christopher Nolan’s “Oppenheimer”—a film exploring the Manhattan Project.

Initial plans were to assemble the plutonium bomb—Fat Man—at Tinian. The spherical nature of the implosion design, with its plutonium pit surrounded by precisely engineered explosive lenses, meant that the bomb had to be put together from the inside out and preferably as close to the location and date of use as possible.

A "Fat Man" bomb was dropped over Nagasaki, Japan, on Aug. 9, 1945, near the end of World War II. Released by the B-29 Bockscar, the 10,000-pound weapon was detonated at an altitude of approximately 1,800 feet over the city. The bomb had an explosive force (yield) of about 20,000 tons of TNT, about the same as the bomb dropped on Hiroshima.

fat man 胖子，是内爆式起爆的钚弹，内爆式因为设计特点，需要设计成圆滚滚的样子，因为需要容纳一圈用于向内施压的炸药。 投放到了长崎。

2014年6月5日 · Little Boy and Fat Man utilized different elements and completely separate methods of construction in order to function as nuclear weapons. Little Boy detonated due to a fission chain reaction involving the isotope U-235 of uranium, while Fat Man used plutonium’s Pu …

Nicknamed “Fat Man” (for England’s Prime Minister Winston Churchill), this bomb had a core of plutonium 239, was 3.5 meters in length by 1.5 meters in diameter, and it weighed 4.5 tons. Its plutonium core was surrounded by 64 explosive charges arranged in an inner and outer shell.

Only this time, a Plutonium bomb nicknamed "Fat Man" was dropped on the city. Even though the "Fat Man" missed by over a mile and a half, it still leveled nearly half the city. Nagasaki's population dropped in one split-second from 422,000 to 383,000. 39,000 were killed, over 25,000 were injured. That blast was less than 10 kilotons as well.

Assembly of a Fat Man bomb was (and may still be) the most complex field preparation operation for any weapon ever made. Like Little Boy, Fat Man was fuzed by four radar units called "Archies", the antennas for which were mounted on the tail of the bomb. Developed originally as fighter tail warning systems, these units measured the bomb's ...