Mark 15 nuclear bomb
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2008-06-21T19:15:41Z
DuncanHill
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correct wikilink from [[Savannah]] to [[Savannah, Georgia]]
[[Image:Mk15.jpg|300x|thumb|right|Mark 15 bomb]]
The '''Mark 15 nuclear bomb''' was a 1950s American [[thermonuclear bomb]], the first relatively lightweight (7,600 lb / 3450 kg) thermonuclear bomb created by the United States.
The Mark 15 was first produced in 1955, in a production run which ended in 1957. The Mark 15 design was in service from 1955 to 1965. A total of 1,200 units were produced in 3 models.
There were three production variants of the Mark 15 bomb, the Mod 1, Mod 2, and Mod 3.
==Transitional design==
The Mark 15 is widely described as a transitional design between fission and thermonuclear weapons. The Mark 15 was a staged weapon (see [[Teller-Ulam design]]), using radiation implosion from a fission nuclear primary (Cobra) to implode a secondary stage. Unlike most more modern thermonuclear bombs, the Mark 15 used a secondary which was primarily [[HEU]] (highly enriched uranium), which generated most of its energy from nuclear fission reactions once the primary imploded it. There was a thermonuclear core which underwent fusion reactions, but most of the energy came from the HEU fissioning. The HEU fission was enhanced by fusion stage neutrons, but would have generated a very significant fission yield by itself.
Some later bombs used depleted uranium fusion stage tampers, and neutrons from the fusion would fission some of the tamper, but the primary energy release (50% or more) was from the fusion reaction.
The HEU secondary tamper concept may have been used in the most modern nuclear weapons, where compact size and weight were highly valued, including the [[W88]] and [[W87#Variants|W87 Mod 1]] weapons.
==Specifications==
All three models were generally physically similar; weight of around 7,600 lb / 3,450 kg, diameter of 34.4 to 35 inches, length of 136 to 140 inches.
<ref>[http://nuclearweaponarchive.org/Usa/Weapons/Allbombs.html Allbombs.html] list of all US nuclear warheads at [http://nuclearweaponarchive.org nuclearweaponarchive.org], Accessed 2005-05-06</ref>
==Dropped and Lost==
On 5 February 1958, during a training mission flown by a [[B-47]], a Mk 15 nuclear bomb was lost off the coast of [[Georgia (U.S. state)|Georgia]] near [[Savannah, Georgia|Savannah]]. It remains missing as of 2008, despite an intensive search. See "[[Tybee Bomb]]" for further details of this incident.
==Models==
The Mod 1 corresponds to the '''Castle Nectar''' test of the '''Zombie''' weapon prototype. This test had a yield of 1.69 [[megaton]]s.
<ref>[http://nuclearweaponarchive.org/Usa/Tests/Castle.html Operation Castle] at [http://nuclearweaponarchive.org nuclearweaponarchive.org], Accessed 2005-05-06</ref>
<ref>[http://www.globalsecurity.org/wmd/systems/nuke-list.htm Historical Nuclear Weapons] at [http://www.globalsecurity.org globalsecurity.org], Accessed 2005-05-06</ref>
The Mod 2 corresponds to the '''Redwing Cherokee''' nuclear test of the '''TX-15-X1''' test model, and had a yield of 3.8 megatons. Redwing Cherokee was the first US thermonuclear bomb airdrop test.
<ref>[http://nuclearweaponarchive.org/Usa/Tests/Redwing.html Operation Redwing] at [http://nuclearweaponarchive.org nuclearweaponarchive.org], Accessed 2005-05-06</ref>
The Mod 3 also appears to have had a 3.8 megaton yield.
===W15===
A missile warhead variant of the Mark 15, the '''W15''' Warhead, was an ongoing project in the mid 1950s. It was cancelled in early 1957. Before cancellation, it had been intended for use on the [[Snark (rocket)|SM-62 Snark]] missile. Instead, the Snark ended up using the W39 (see below).
==Derivatives==
The [[W39]] nuclear warhead and [[B39 nuclear bomb]] used a common nuclear ''[[physics package]]'' which was derived from the Mark 15. The experimental W39 devices were initially tested as the '''TX-15-X3''' (which is identical to the W39 Mod 0 design).
==See also==
* [[List of nuclear weapons]]
* [[Operation Castle]]
* [[Operation Redwing]]
* [[Tybee Bomb]]
==References==
<references/>
==External links==
* [http://nuclearweaponarchive.org/Usa/Weapons/Allbombs.html Allbombs.html] list of all US nuclear warheads at [http://nuclearweaponarchive.org nuclearweaponarchive.org]
[[Category:American Cold War nuclear bombs]]
For more information regarding lost nuclear bombs goto [http://www.tybeebomb.com tybeebomb.com]