Mark 21 nuclear bomb
Encyclopedia
The Mark 21 nuclear bomb was a United States
nuclear 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
). At 12 feet, six inches long, 56 inches in diameter and weighing 15,000 pounds (6,800 kg) - less than half the Mk-17/24 weapons - the Mk-21 was significantly smaller than its predecessors. Its minimum yield was specified at four megatons.
Quantity production of the Mk-21 started in December 1955 and ran until July 1956. Three marks were produced; the Mk-21C was proof tested as the Operation Redwing
Navajo shot, with a yield of 4.5 megatons. Starting in June of 1957 all Mk-21 bombs were converted to the more powerful Mk-36, which was removed from service in 1962.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
nuclear gravity bomb
Gravity bomb
An unguided bomb, also known as a free-fall bomb, gravity bomb, dumb bomb, or iron bomb, is a conventional aircraft-delivered bomb that does not contain a guidance system and hence, simply follows a ballistic trajectory....
first produced in 1955. It was based on the TX-21 "Shrimp" prototype that had been detonated during the Castle Bravo
Castle Bravo
Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb device, detonated on March 1, 1954 at Bikini Atoll, Marshall Islands, as the first test of Operation Castle. Castle Bravo was the most powerful nuclear device ever detonated by the United States ,...
test in March 1954. While most of the Operation Castle
Operation Castle
Operation Castle was a United States series of high-energy nuclear tests by Joint Task Force SEVEN at Bikini Atoll beginning in March 1954...
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
Mark 14 nuclear bomb
For the Sinclair Research Ltd. SC/MP based computer system see MK14.The Mark 14 nuclear bomb was a 1950s American thermonuclear bomb, the first solid-fuel staged hydrogen bomb. It was an experimental design, and only five units were produced in early 1954. It was tested in April 1954 during the...
, Mk 17
Mark 17 nuclear bomb
The Mark 17 and Mark 24 were the first mass-produced hydrogen bombs deployed by the United States. The two differed in their "primary" stages. The MK 17/24 bombs were long, diameter. They weighed 21 tons. The Mark 17 had a yield in the range of 25 megatons TNT equivalent...
& Mk 24
Mark 24 nuclear bomb
The Mark 24 nuclear bomb was an American thermonuclear bomb design, based on the third American thermonuclear bomb test, Castle Yankee. The Mark 24 bomb was tied as the largest weight and size nuclear bomb ever deployed by the United states, with the same size and weight as the Mark 17 nuclear...
). At 12 feet, six inches long, 56 inches in diameter and weighing 15,000 pounds (6,800 kg) - less than half the Mk-17/24 weapons - the Mk-21 was significantly smaller than its predecessors. Its minimum yield was specified at four megatons.
Quantity production of the Mk-21 started in December 1955 and ran until July 1956. Three marks were produced; the Mk-21C was proof tested as the Operation Redwing
Operation Redwing
Operation Redwing was a United States series of 17 nuclear test detonations from May to July 1956. They were conducted at Bikini and Enewetak atolls. The entire operation followed Operation Wigwam and preceded Operation Plumbbob. The primary intention was to test new, second-generation...
Navajo shot, with a yield of 4.5 megatons. Starting in June of 1957 all Mk-21 bombs were converted to the more powerful Mk-36, which was removed from service in 1962.