View source for W40 (nuclear warhead)

{{Short description|American nuclear warhead}}
{{more citations needed|date=January 2021}}
The '''W40 nuclear warhead''' was an American [[Boosted fission weapon|fusion-boosted fission]] [[nuclear bomb|nuclear warhead]] developed in the late 1950s and which saw service from 1959 to 1972.
The W40 design was reportedly the common [[Python primary]] or fission core used by the US [[B28 nuclear bomb]], [[W28 (nuclear warhead)|W28 nuclear warhead]], and [[W49|W49 nuclear warhead]].
The W40 was {{cvt|18|in|||}} in diameter, {{cvt|32|in|||}} long, and weighed around {{cvt|385|lb||}}.  It had a design yield of 10 [[kiloton]]s.
The W40 was used in the [[MGM-18 Lacrosse]] surface to surface missile (SRBM) and [[CIM-10 Bomarc]] [[surface to air missile]] (SAM).
The Bomarc warhead was lethal to a medium bomber aircraft up to about one kilometer. The warheads were mounted to the missiles for 90 day intervals, after which they underwent periodic inspection and maintenance.
The first production device was made in January 1959, with production starting in June, withdrawal in August due to a significant safety issue, and re-release in September with a temporary fix. A one-point safety problem was discovered in 1960 and a W40 mod 2 with a fix was developed and sent out in December 1963.<ref>{{Cite book | url=https://books.google.com/books?id=0s2V4fxHfS4C&q=w40+warhead&pg=PA59 | title=Canadian Nuclear Weapons: The Untold Story of Canada's Cold War Arsenal| isbn=9781554881215| last1=Clearwater| first1=John| date=February 1998}}</ref>
==See also==
* [[List of nuclear weapons]]
==External links==
* [http://nuclearweaponarchive.org/Usa/Weapons/Allbombs.html Allbombs.html] list of all US nuclear weapons at [http://nuclearweaponarchive.org nuclearweaponarchive.org]
<references/>
{{United States nuclear devices}}
[[Category:Nuclear warheads of the United States]]
[[Category:Military equipment introduced in the 1950s]]
{{Nuclear-weapon-stub}}
{{US-mil-hist-stub}}