Project E was a joint project between the United States and the United Kingdom during the cold war to provide nuclear weapons to the British Royal Air Force (RAF) prior to Britain's own nuclear weapons becoming available. Later sometimes used more widely to refer to similar arrangements for the British Army of the Rhine.[1]
The first record of this project was in 1958 concerning the provision of Mk 7 weapons to be carried by the Canberra bomber.[2]
Later, Mk 5 weapons were provided for the V-Bomber force.[3] This provision was problematic for the RAF since United States Air Force (USAF) personnel had guardianship of these weapons at all times and they could not be dispersed to dispersal airfields as the RAF desired. As a result the weapons were returned to the United States as soon as possible[4] when British-made nuclear and thermonuclear weapons became available. In the United Kingdom, Project E came to an end in 1965, while in forces assigned to the North Atlantic Treaty Organization it lasted until 1969. It was replaced by the NATO nuclear sharing concept for tactical nuclear weapons, which, for example, included the provision of B57 nuclear depth bombs for the Avro Shackleton and Hawker Siddeley Nimrod until 1992.
A note by U.S. President Dwight D. Eisenhower quoted him as saying:
To this purpose, discussions were held around the use of Mk 15 thermonuclear weapons but no evidence of these actually being carried on British V-Bombers exists.[6]
It should also be noted that when Valiant aircraft were allocated to SACEUR in 1960 they carried either B28[7] or B43 thermonuclear weapons. When co-located with non SACEUR squadrons the SACEUR squadrons were often fenced off with six foot fences on the QRA pads. These were allowed to be carried by the RAF under control of SACEUR on the same basis as Project E weapons carried by the RAF, i.e. U.S. guardians present at all times. This of course came to an end when all the Valiants were grounded on 9 December 1964.[8] The B28 bomb later became famous as a result of the Palomares incident in 1966.