Mark 21 nuclear bomb
| Mark 21 | |
|---|---|
| Type | Thermonuclear weapon |
| Service history | |
| Used by | United States |
| Production history | |
| Produced | December 1955 to July 1956 |
| No. built | 275 weapons produced in Y1 variant. |
| Variants | 2 |
| Specifications | |
| Mass | 17,600 pounds (8,000 kg) |
| Length | 12 feet 4.37 inches (3.7686 m) |
| Diameter | 58.48 inches (148.5 cm) |
| Blast yield | 18 megatons (USAF claim, although never tested). |
The Mark 21 nuclear bomb was a United States thermonuclear gravity bomb first produced in 1955. It was based on the TX 21 "Shrimp" prototype that had been detonated during the Castle Bravo test in March 1954. While most of the Operation Castle tests were intended to evaluate weapons intended for immediate stockpile, or which were already available for use as part of the Emergency Capability Program, Castle Bravo was intended to test a design which would drastically reduce the size and costs of the first generation of air-droppable atomic weapons (the Mk 14, Mk 17 & Mk 24).