Mark 18 nuclear bomb

Source: Wikipedia, the free encyclopedia.

The Mark 18 nuclear bomb, also known as the SOB or Super

fission bomb produced by the US. The Mark 18 had a design yield of 500 kilotons. Nuclear weapon designer Ted Taylor
was the lead designer for the Mark 18.

The Ivy King test firing of the Mark 18 SOB design

The Mark 18 was tested once, in the

Enewetak atoll in the Pacific Ocean
on November 16 1952. The test was a complete success at full yield.


The Mark 18 bomb design used an advanced 92-point implosion system, derived from the

aluminum/boron chain designed to absorb neutrons was placed in the fissile pit to reduce the risk of accidental high yield detonation, and removed during the last steps of the arming sequence.[1][2]


Beginning in March 1953, the United States deployed a number of Mark 18 bombs. A total of 90 were manufactured and placed in service.

The weapon had a short lifetime, and was replaced by

thermonuclear weapons in the mid-1950s. The Mark 18 weapons were all modified into lower yield Mark 6 nuclear bomb
variants in 1956.

See also


  1. ^ Allbombs.html list of all US nuclear warheads at Accessed April 16, 2007.
  2. ^ Historical US nuclear weapons at, accessed April 17, 2007