British Nuclear Weapons Part 2: From Air to Sea

© IWM (A 35106)
Welcome back! In Part 1 we spoke about the development of the British nuclear programme and the early nuclear weapons used. In this instalment of the series, we are going to focus on two British nuclear programmes: Polaris and Chevaline.

Late 1950s
In 1957 the Soviet Union launched Sputnik which was the world's first satellite. Naturally, this caused increased fear amongst the Western powers. As a result, British Prime Minister Harold Macmillan pushed for Britain and the US to share technology and nuclear secrets. At this time, Britain was using the Blue Streak programme which was eventually withdrawn in 1960 for being too slow and inferior to Soviet missiles. Britain then favoured the American Skybolt until this was scrapped in 1962 because of test failures.
© Crown copyright. IWM (A 35135)

In 1962 Macmillan and US President John F. Kennedy met in Nassau in the Bahamas for negotiations. Macmillan demanded that the US should supply their Polaris missiles to Britain for use as deterrents. UGM-27 Polaris was a submarine launched ballistic missile with a 2 stage solid fuelled rocket system.

Initially Kennedy was reluctant to reach an agreement as he was concerned that it would prevent Britain from entering the European Economic Community. Despite this an agreement was made in April 1963 under the Polaris Sales Agreement.

The Polaris system entered service with the Royal Naval Service in 1968 and V-Bombers were withdrawn by 1969. Each submarine carried 16 Polaris missiles.

Meanwhile, the Soviet Union's anti-ballistic defences were improving. This meant that Polaris had to be improved as it was not designed to penetrate such advanced anti-ballistic defences.
Tip of a Chevaline Warhead at Aerospace Bristol


Chevaline was to be the replacement for Polaris. This was a project embarked upon by the Conservative Heath Government from 1970. It was then fully developed by the Labour governments of Harold Wilson and James Callaghan and completed by Margaret Thatcher.

Chevaline had 2 hydrogen bomb warheads and 27 decoys. Together this provided a total of 551 credible threats per submarine as each one carried 19 missiles. Previously Polaris did not have decoys and therefore only provided 48 potential threats per submarine. The aim was for the decoys to distract Russian defence missiles thus leaving the active warheads to cause damage as Russian defences did not know what was real and what was a decoy.

The Chevaline project was kept top secret. It was never discussed in Cabinet and was only mentioned in 1980 in a Parliamentary debate regarding the improvement of NATO nuclear forces. It was supposed to cost £250 million but by 1975 it cost £400milion and in total it cost £1 billion making it the most expensive defence project not to be made public.

Chevaline entered service in 1982 onboard the submarines HMS Renown, Resolution, Revenge and Repulse and were kept in Scotland. There were many delays in putting it into force as the project was started in 1970 but not fully developed for 12 years. There were also major maintenance issued with Chevaline as it was used by the Navy long after it was retired from the US Navy so it was difficult to get spare parts if anything went wrong. It was decommissioned and replaced by Trident in 1996.

So that's it for our second instalment in the British Nuclear Weapons series. Stay tuned for part 3!

Further Reading 
How did Britain get involved in the Nuclear Arms Race
Skybolt & Polaris Missiles 
Polaris and the History of British Nuclear Weapons 
The History of the UK's Nuclear Weapons Programme 
History of the British Nuclear Arsenal


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