Model name: "Fat Man" Atomic Bomb
Application: Collection,Souvenir Gift, Home Office Decoration,Educational,Model display
Age Range: > 14 years old
Type: 3D printed model
Material: PETG Plastic
Scale: 1:20
Size: approx 16cm(L)/6.3inch(L)
Package:Missile model kit,Simple packaging
The "Fat Man" Atomic Bomb: The Second Nuclear Weapon Used in Warfare
"Fat Man" was the codename for the type of atomic bomb dropped on the Japanese city of Nagasaki on August 9, 1945. It was the second and last nuclear weapon ever used in combat, leading to Japan's surrender and the end of World War II.
Key Features & Design
Design Type: Implosion-Design
Unlike the "Little Boy" bomb dropped on Hiroshima, which used a gun-type mechanism, "Fat Man" used a more complex and efficient implosion design.
Its core was a sub-critical sphere of plutonium-239. Conventional high explosives (specifically, Composition B and Baratol) were arranged in lenses around the core. When detonated with extreme precision, these explosives created a perfectly symmetrical shockwave that compressed the plutonium sphere to a super-critical density, initiating a massive nuclear chain reaction.
Physical Characteristics:
Name Origin: The bomb was nicknamed "Fat Man" by its creators because of its wide, round shape, which resembled Winston Churchill.
Dimensions: It was 10 feet 8 inches (3.3 meters) long and 5 feet (1.5 meters) in diameter.
Weight: It weighed approximately 10,300 pounds (4,670 kg).
Explosive Yield:
The explosion yielded the equivalent of about 21 kilotons of TNT.
This was significantly more powerful than the ~15-kiloton "Little Boy" bomb used on Hiroshima, despite using less fissile material, demonstrating the efficiency of the implosion design.
The Mission: Nagasaki
The B-29 Carrier: The bomb was carried and dropped by the B-29 Superfortress bomber named "Bockscar," piloted by Major Charles W. Sweeney. The original target for the mission was the city of Kokura, but due to poor visibility, the crew proceeded to the secondary target, Nagasaki.
Detonation: At 11:02 a.m. local time, "Fat Man" was dropped over the industrial valley of Nagasaki. It detonated 1,650 feet (503 meters) above the ground, unleashing immense heat, blast force, and radiation.
Aftermath: The explosion instantly killed an estimated 40,000 to 70,000 people, with tens of thousands more dying later from injuries and radiation sickness. The devastation led to Emperor Hirohito's announcement of Japan's surrender on August 15, 1945.
Historical Context and Significance
The Manhattan Project: "Fat Man" was the product of the top-secret U.S. Manhattan Project. Its complex implosion design was developed at Los Alamos Laboratory under the direction of J. Robert Oppenheimer, with key contributions from scientists like Seth Neddermeyer.
The Trinity Test: The first successful test of a plutonium implosion device, codenamed "The Gadget," was conducted at the Trinity test site in New Mexico on July 16, 1945. The success of this test confirmed that the "Fat Man" design was viable.
A Defining Weapon of the 20th Century: The use of "Fat Man" and "Little Boy" ushered in the atomic age, fundamentally altering global politics and warfare. It created a new reality of mutual assured destruction and initiated the nuclear arms race that defined the Cold War.
In summary, the "Fat Man" bomb was not only a devastating weapon that ended World War II but also a revolutionary technological achievement whose design principles became the standard for virtually all future nuclear weapons.