page_title: WE.177
section_title: WE.177B
hierarchical_section_title: WE.177 / Versions / WE.177B
caption_attribution_description: Png version of en:Image:WE.177B-profile.jpg created by me Ian Dunster 19:52, 26 May 2006 (UTC) using the original drawn and uploaded by Brian Burnell the copyright holder in this format. Summary Drawing Artist: Self
context_page_description: The WE.177, originally styled as WE 177, and sometimes simply as WE177, was a series of tactical and strategic nuclear weapons equipping the Royal Navy and the Royal Air Force. It was the primary air-dropped nuclear weapon in the United Kingdom from the late 1960s into the 1990s.
  The underlying design was based on the US W59, which the UK had gained as part of their involvement in the GAM-87 Skybolt program. The RAF was not happy with the primary stage of the W59, which was potentially subject to accidental detonation when subject to mechanical shocks. Air Ministry Operational Requirement OR.1177 was issued for a new design using a less sensitive explosive, which was undertaken at the Atomic Weapons Research Establishment as "Cleo". When Skybolt was cancelled, the UK gained access to the UGM-27 Polaris missile and its W58 warhead, but they continued development of Cleo as a tactical weapon to replace Red Beard. A later requirement for a much smaller tactical and anti-submarine weapon for Navy use was filled by using the new primary as a boosted fission weapon.
  Three versions were produced, A, B and C.
context_section_description: WE.177B weighed 457 kilograms (1,008 lb), with a fixed yield of 450 kt (1900 TJ).  Although it weighed in excess of 1000 lb, it was known in RAF Service as the 'Bomb, Aircraft, HE 950lb MC', to differentiate it from the conventional 'Bomb, Aircraft, 1000 lb GP HE', which gave rise to its popular name '950'.  WE.177B had airburst, impact, or laydown options.
  Numbers built are still uncertain, but reliable sources put the figure at fifty-three (53), and all were retired by August 1998.  When Polaris became operational, the Vulcan force continued in a sub-strategic tactical role with these and other bombs assigned to the NATO SACEUR.  With the retirement of the Vulcans, WE.177B was carried by successor aircraft, including the Panavia Tornado.
caption: WE.177B & C
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