Kinglet was a boosted fission primary used in several American thermonuclear weapons. The W55 warhead for the UUM-44 SUBROC anti-submarine missile and the W58 warhead for Polaris A-3 were designed to use Kinglet, while the W47 warhead for Polaris A-1/A-2 were retrofitted with Kinglet to overcome the technical issues with the Robin primary the W47 was initially deployed with. Allegedly, only the W47Y2 was converted to the Mod 3 design using Kinglet. Design The Kinglet device was approximately in diameter, in length and weighed approximately . The device was of the two-point design. Two-point devices only require two detonators to fire the whole device, compared to earlier nuclear weapons that required tens of detonators. Characteristics of the warheads that used Kinglet are: See also List of nuclear weapons Teller-Ulam design Tsetse primary Python primary Notes References Bibliography Beware the old story by Chuck Hansen, Bulletin of the Atomic Scientists, March/April 2001 pp. 52-55 (vol. 57, no. 02) http://nuclearweaponarchive.org/Usa/Weapons?Allbombs.html The History of the UK. Strategic Deterrent: The Chevaline Programme. Published:2004 by the Royal Aeronautical Society, London. Nuclear bombs of the United States