Who would have thought that part of the secret to Britain’s Cold War nuclear arsenal was chickens? In the decades after the Second World War, various scenarios were conceived for a potential World War Three, one of which was that the invading Soviet army would march across central Europe to meet Nato forces. To combat this, the British conceived an idea that, carefully concealed under strategically important bridges and other locations in Germany, would be a number of ‘Blue Peacocks’. This was no beautiful bird but an ugly monstrosity, as tall as an adult and a couple of metres long. Inside this large metal tube was a spherical device surrounded by lots of complicated wires – and several chickens. The logic was simple – the device could be armed and set to explode at a pre-defined time in advance. But buried in the ground in Germany, the devices could get very cold, and the purpose of the chickens was to keep the device at a certain temperature, so that it would detonate at the correct time. If one of these devices had been activated, the subsequent nuclear explosion would have been equivalent to 10,000 tonnes of TNT (10 kilotons) – enough to destroy central London if a similar device was exploded in Trafalgar Square.


When was Britain’s first nuclear weapon?

Although Blue Peacock was designed and built, it was never deployed. It would have been part of Britain’s nuclear arsenal had war with the Soviet Union broken out, but it was designed as a weapon of last resort. The whole idea of creating a nuclear deterrent was just that – a means to deter the Soviets and thereby stop war breaking out. Britain had been an integral partner in the wartime Manhattan Project [the programme to develop a functional atomic weapon during the Second World War], but, with the end of hostilities in 1945, questions arose as to the future relationship. A year later, Senator Brien McMahon’s act of Congress forbade the exchange of technical information and so, a further year later in January 1947, Prime Minister Clement Attlee made the decision for Britain to develop its own independent nuclear bomb.

Britain's H-Bomb explosion
With the detonation of its H-Bomb, Britain became the third power (after the US and the Soviet Union) to enter the nuclear age. Photo by Keystone/Getty Images)

Why did Britain need a nuclear capability? Several factors were important: it was assumed that the Soviet Union would acquire them; the best means of defence against someone else having nuclear weapons was to have your own nuclear weapons; there was no international agreement on their use; and it allowed Britain to remain at the high table of international politics, particularly vis-à-vis the Americans. The Foreign Secretary, Ernest Bevin, is famously said to have commented at a Cabinet meeting: “We’ve got to have this… we’ve got to have a bloody Union Jack flying on top of it.” In October 1952 Attlee and Bevin’s desire was realised – off the north-western coast of Australia, at just after midnight in London, Britain became the third power (after the US and the Soviet Union) to enter the nuclear age. The detonation of the 25 kiloton device was awe-inspiring. The scientific director, William Penney, declared how “the sight before our eyes was terrifying”.

The V-Force: Britain’s airborne nuclear threat

By 1952 the Cold War had well and truly arrived. Stalin’s Soviet Union had increased its control over large swathes of eastern and central Europe; Mao’s communist party had triumphed in the Chinese civil war; while in Korea a nasty conflict had been raging between North and South, both proxies for the communist and capitalist superpowers. Possessing nuclear weapons was therefore of paramount concern for Britain. The first bombs were to be delivered by the RAF via plane – initially the nuclear weapons were simply spherical balls that would be dropped on a target, but as the 1950s wore on, they became far more technologically advanced with the V-Force becoming the principal means of delivery. This was the name given to three different bombers – the Vulcan, Valiant and Victor – each of which had different specifications, but each of which was designed to carry a nuclear payload.

American students practice a 'duck and cover' drill., children pictured under tables
By 1952 the Cold War had well and truly arrived and the threat of nuclear war was felt all over the globe. Here, American students practice a 'duck and cover' drill. (Photo by GraphicaArtis/Getty Images)

The V-Force were fast, modern aircraft, but as technology continued to develop, they began to grow obsolete as weapons of war. German scientists in the Second World War had demonstrated the power of missiles: the V1 and V2 had caused significant damage and destruction in Britain. Post-war, many of these same scientists were employed by the victorious Allied powers, and by the late 1950s their efforts bore fruit. The next generation of Britain’s nuclear weapons were designed not to be carried by aeroplane but had been shrunken to fit atop a missile. Missiles held a number of key advantages over planes as a delivery vehicle – they flew far higher and significantly faster and so were far harder to intercept once launched. Britain’s plan was to use the monstrous Blue Streak missile to deliver nuclear weapons to their target. The missile was the height of a 7-storey building and the original plan was to build 64 of them, each equipped with a nuclear warhead.

A black-and-white photograph of the Handley Page Victor bomber, on the ground against the sky
A version of the Handley Page Victor bomber at Radlett in Hertfordshire, March 1959. (Photo by Reg Birkett/Keystone/Hulton Archive/Getty Images)

Blue Streak was designed and developed by Britain, but was cancelled before it entered full production as a military device (it would subsequently be used for space research). Instead, in 1960, Prime Minister Harold Macmillan made the decision to purchase the US-built Skybolt missile system. These were designed to be air-launched from a Vulcan bomber, but before they could be deployed the US cancelled the programme. At Nassau in the Bahamas, just a few days before Christmas in 1962, Macmillan and US President John F Kennedy agreed that Britain would purchase the American Polaris missile instead. British warheads were to be attached to US Polaris missiles, to be launched from British submarines. From that point forward the future of the nuclear deterrent primarily lay not with aircraft, but with submarines.

A permanent nuclear presence

Four submarines were built, each equipped with up to 16 missiles, each of which carried a variety of different warhead configurations. This was a permanent nuclear presence, with a number of submarines constantly on patrol around the world, ready to strike whenever required. Ever since that point and into the 21st century, Britain’s nuclear deterrent has been based on submarines. The technology has evolved, from the improved Chevaline missiles devised in the 1970s, to the Trident system of the 1980s.

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Britain currently maintains four nuclear submarines – the Vanguard, Victorious, Vigilant and Vengeance. Just like the boats of the 1960s, these are constantly on patrol around the globe, providing the ability to launch Trident missiles, each armed with up to eight nuclear warheads. The latest iteration of the Trident missile has a reported range of more than 7,000 miles, and the Royal Navy states that at its fastest, it can fly at speeds of over 13,000 miles per hour.

Historical opposition and the future

Since their deployment in the late 1950s there has been a sizable opposition to Britain’s possession of nuclear weapons. The principal critics have been CND – the Campaign for Nuclear Disarmament. The campaign’s main argument has been that Britain should take the initiative in scrapping its nuclear deterrent in the hope that it would spur the other nuclear nations to do the same. For many opponents, the end of the Cold War removed what little justification had existed for possessing nuclear weapons. Today this argument is not just about the utility of the nuclear deterrent, but also its cost relative to other priorities that the government faces.

A CND demonstration, protestors holding placards
Since the mid-20th century, CND has campaigned for Britain to scrap its nuclear deterrent in the hope that it would spur the other nuclear nations to do the same. (Photo by Evening Standard/Getty Images)

The Vanguard system of nuclear submarines had entered service by the late 1990s and was originally intended to have a lifespan of 25 years. In July 2016 the decision was made by Parliament to extend Britain’s nuclear deterrent by replacing the Vanguard submarines with a new class of boat – the Dreadnought. These are intended to enter service in the 2030s with four submarines planned – Dreadnought, Valient, Warspite and King George VI. Ernest Bevin’s 1946 desire to have “a bloody Union Jack flying on top of it” is alive and well.


Michael S Goodman is Professor of Intelligence and International Affairs at the Department of War Studies, King’s College London