WE.177

WE.177
A mostly green coloured bomb around 3 metres long, marked with the word "training" and with 4 fins at the rear
WE.177 nuclear bomb (training example) at Explosion Museum of Naval Firepower
TypeFree-fall gravity nuclear bomb
Place of originUnited Kingdom[1]
Service history
In serviceSeptember 1966–1998[1][2][3]
Used byRoyal Navy and Royal Air Force
WarsCold War
Production history
DesignerAtomic Weapons Research Establishment (AWRE), Aldermaston[2]
ManufacturerAtomic Weapons Research Establishment (AWRE), Aldermaston[2]
Unit costunknown
No. built~319
VariantsWE.177A, WE.177B, WE.177C
Specifications
MassWE.177A: 272 kilograms (600 lb),[1][3]
WE.177B and WE.177C: 457 kilograms (1,010 lb),[1]
LengthWE.177A: 112 inches (284 cm),[1]
WE.177B and WE.177C: 133 inches (338 cm),[1]
Diameter16 inches (41 cm),[1]
FillingWE.177A: ZA297 primary fission warhead[1]
WE.177B: ZA297 primary fission warhead & PT176 secondary thermonuclear fusion warhead[1]
WE.177C: ZA297 primary fission warhead & PT176 secondary thermonuclear fusion warhead[1]
Filling weightunknown
Blast yieldWE.177A: 0.5 kilotons or 10 kilotons[1]
WE.177B: 450 kilotons[1]
WE.177C: 200 kilotons[1]
Nuclear weapons
Photograph of a mock-up of the Little Boy nuclear weapon dropped on Hiroshima, Japan, in August 1945.
Background
Nuclear-armed states
NPT recognized
United States
Russia
United Kingdom
France
China
Others
India
Israel (undeclared)
Pakistan
North Korea
Former
South Africa
Belarus
Kazakhstan
Ukraine

The WE.177, originally styled as WE 177,[1][2] and sometimes simply as WE177,[3][4] was a series of tactical and strategic nuclear weapons with which the Royal Navy (RN) and the Royal Air Force (RAF) were equipped. 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[1] 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. The first to be produced was the 450 kilotonnes of TNT (1,900 TJ) WE.177B, which entered service with the RAF at RAF Cottesmore in September 1966. Further deliveries were delayed by the need to complete the warheads for the Polaris A3T. The Navy did not begin to receive its ~10 kt (42 TJ) WE.177As until 1969. The 190 kt (800 TJ) C models for the RAF followed.

All versions could be delivered by fixed-wing aircraft and could be parachute retarded. The WE.177A, in anti-submarine mode, could also be carried by helicopters.

The Navy weapons were retired by 1992, and all other weapons with the RAF were retired by 1998. When it was finally withdrawn in 1998, the WE.177 had been in service longer than any other British nuclear weapon. The WE.177 was the last nuclear bomb in service with the Royal Air Force, and the last tactical nuclear weapon deployed by the UK.

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  2. ^ a b c d Cite error: The named reference AWE was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference CDI.org-UKnukes was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference OpCORPORATE was invoked but never defined (see the help page).