Mark 4 nuclear bomb
| Mark 4 nuclear bomb | |
|---|---|
A Mark 4N riveted aluminum bomb casing. Stockpile Mk 4s used a 2,830 lb (1,280 kg) steel casing. | |
| Type | Air-dropped Nuclear fission weapon |
| Place of origin | United States |
| Service history | |
| In service | 1949–1953 |
| Used by | United States Air Force (USAF) |
| Production history | |
| No. built | About 550 |
| Specifications | |
| Mass | 10,800 to 10,900 pounds (4,900 to 4,940 kg) |
| Length | 128 in (3,300 mm) |
| Diameter | 60 in (1,500 mm) |
| Crew | 1x Weaponeer for pit insertion and arming |
| Filling | Composite uranium and plutonium fissile pits |
Detonation mechanism | focused high explosive implosion |
| Blast yield | 1, 3.5, 8, 14, 21, 22, 31 kt (4.2, 14.6, 33.5, 58.6, 87.9, 92.0, 129.7 TJ), depending on construction and/or pit |
The Mark 4 nuclear bomb was an American implosion-type nuclear bomb based on the earlier Mark 3 Fat Man design, used in the Trinity test and the bombing of Nagasaki. With the Mark 3 needing each individual component to be hand-assembled by only highly trained technicians under closely controlled conditions, the purpose of the Mark 4 was to produce an atomic weapon as a practical piece of ordnance. The Mark 4 Mod 0 entered the stockpile starting March 19, 1949 and was in use until 1953. With over 500 units procured, the Mark 4 was the first mass-produced nuclear weapon.