The United Kingdom's Polaris programme, officially named the British Naval Ballistic Missile System, provided its first submarine-based nuclear weapons system. Polaris was in service from 1968 to 1996.
Polaris itself was an operational system of four ballistic missile submarines, each armed with 16 Polaris A-3 ballistic missiles. Each missile was able to deliver three ET.317 thermonuclear warheads. This configuration was later upgraded to carry two warheads hardened against the effects of radiation and nuclear electromagnetic pulse, along with a range of decoys.
The British Polaris programme was announced in December 1962 following the Nassau Agreement between the US and the UK. The Polaris Sales Agreement provided the formal framework for cooperation. Construction of the submarines began in 1964, and the first patrol took place in June 1968. All four boats were operational in December 1969. They were operated by the Royal Navy, and based at Clyde Naval Base on Scotland's west coast, a few miles from Glasgow. At least one submarine was always on patrol to provide a continuous at-sea deterrent.
In the 1970s it was considered that the re-entry vehicles were vulnerable to the Soviet anti-ballistic missile screen concentrated around Moscow. To ensure that a credible and independent nuclear deterrent was maintained, the UK developed an improved front end named Chevaline. There was controversy when this project became public knowledge in 1980, as it had been kept secret by four successive governments while incurring huge expenditure. Polaris patrols continued until May 1996, by which time the phased handover to the replacement Trident system had been completed.
Background
During the early part of the Second World War, the UK had a nuclear weapons project, codenamed Tube Alloys. At the Quebec Conference in August 1943, the prime minister, Winston Churchill, and the president of the United States, Franklin Roosevelt, signed the Quebec Agreement, which merged Tube Alloys with the American Manhattan Project to create a combined British, American and Canadian project. The British government trusted that the United States would continue to share nuclear technology, which it regarded as a joint discovery, but the United States Atomic Energy Act of 1946 (McMahon Act) ended technical cooperation.
The British government feared resurgence of United States isolationism, as had occurred after the First World War, in which case the UK might have to fight an aggressor alone; or that the UK might lose its great power status and its influence in world affairs. It therefore restarted its own development effort, now codenamed High Explosive Research. The first British atomic bomb was tested in Operation Hurricane on 3 October 1952.
During the 1950s, the UK's nuclear deterrent was based around the V-bombers of the Royal Air Force (RAF), but developments in radar and surface-to-air missiles made it clear that bombers were becoming increasingly vulnerable, and would be unlikely to penetrate Soviet airspace in the 1970s. Free-fall nuclear weapons were losing credibility as a deterrent. To address this problem, the United Kingdom embarked on the development of a Medium Range Ballistic Missile called Blue Streak. By 1959—before it had even entered service—serious concerns had been raised about its own vulnerability, as it was liquid-fuelled and deployed above ground, and therefore extremely vulnerable to a pre-emptive nuclear strike.
Royal Navy and Polaris Nuclear ambitions
The Royal Navy began seeking a nuclear role as early as 1945, when the Naval Staff suggested the possibility of launching missiles with atomic warheads from ships or submarines. In 1948 it proposed using carrier-based aircraft for nuclear weapons delivery, although atomic bombs small enough to be carried by them did not yet exist. Its "carriers versus bombers" debate with the RAF resembled the similar inter-service dispute in the United States at this time that led to the "Revolt of the Admirals". The demand for a nuclear-capable carrier bomber led to the development of the Blackburn Buccaneer. It required a small warhead, which drove the development of the Red Beard. The Defence Research Policy Committee (DRPC) considered the prospect of arming submarines with nuclear missiles, but its March 1954 report highlighted technical problems that it did not expect to be resolved for many years.
Studies of nuclear reactors for nuclear marine propulsion commenced in December 1949, but research at the Atomic Energy Research Establishment (AERE) at Harwell was directed towards development of a gas-cooled, graphite-moderated reactor which January 1952 studies showed was too large for use by the Royal Navy, and not into a Pressurised Water Reactor (PWR) of the kind that the US Navy had under development, as the United Kingdom Atomic Energy Authority did not see this kind of reactor as having civil application. Submarine propulsion research was suspended in October 1952 to conserve plutonium production for nuclear weapons, and by 1954 the Royal Navy had concluded that it would not be possible until the 1960s. The US Navy's first nuclear-powered submarine, , became operational on 17 January 1955.
One reason the Royal Navy lagged behind its American counterpart was the lack of a high-ranking champion who would push nuclear submarine development. This changed when Admiral Lord Mountbatten became First Sea Lord in April 1955. In June he secured the approval of the Board of Admiralty to build a nuclear-powered submarine. This coincided with Admiral Arleigh Burke's appointment as the US Navy's Chief of Naval Operations (CNO) in August. Mountbatten visited the United States in October, and through his friendship with Burke, arranged for US Navy cooperation in submarine development. Burke's support was crucial, as the United States Congress Joint Committee on Atomic Energy was uncertain about the legality of transferring such technology to the UK, and Rear Admiral Hyman G. Rickover, the head of the US Navy's nuclear propulsion project, was opposed. But the United States Department of Defense supported the British request, and Mountbatten won Rickover over during a visit to the UK in August 1956. Rickover withdrew his objections in early 1957.
In December 1957, Rickover proposed that Westinghouse be permitted to sell the Royal Navy a nuclear submarine reactor, which would allow it to immediately proceed with building its own nuclear-powered submarine. The British government endorsed this idea, as it saved a great deal of money. The British development of the hydrogen bomb, and a favourable international relations climate created by the Sputnik crisis, facilitated the amendment of the McMahon Act to permit this, and the transfer of submarine reactor technology was incorporated in the 1958 US–UK Mutual Defence Agreement, which allowed the UK to acquire nuclear weapons systems from the United States, thereby restoring the nuclear Special Relationship.
Polaris development
One of Burke's first actions as CNO was to call for a report on the progress of ballistic missile research. The US Navy was involved in a cooperative venture with the US Army to develop the Jupiter missile, although there were concerns about the viability and safety of a liquid-fuel rocket at sea. To handle the Navy's side of the joint project, the United States Secretary of the Navy, Charles Thomas, created the Special Projects Office (SPO), with Rear Admiral William F. Raborn, Jr., a naval aviator, as its director. Apart from nuclear propulsion, the technologies required for a ballistic missile submarine—a long-range solid propellant rocket, a light-weight thermonuclear warhead, a compact missile guidance system, and an inertial navigation system for the submarine—did not exist in 1955.
A turning point came during Project Nobska in the summer of 1956, when Edward Teller predicted that a warhead would become available by 1963. This was much lighter than the warhead of the Jupiter, and led the US Navy to pull out of the joint Jupiter project in late 1956 in order to concentrate on the development of a solid-fuel rocket, which became Polaris. In May 1958, Burke arranged for the appointment of a Royal Navy liaison officer, Commander Michael Simeon, on the SPO staff. In 1955, the SPO staff consisted of 45 officers and 45 civilians; by mid-1961, it had grown to 200 officers and 667 civilians. By then, over 11,000 contractors were involved, and it had a budget of $2 billion. SPO had to overcome formidable technological challenges; but its success was also due to Burke's marketing of Polaris as a second strike weapon. In this role, its capabilities were highlighted and its limitations minimised. The first Polaris boat, , fired a Polaris missile on 20 July 1960, and commenced its initial operational patrol on 16 November 1960.
The idea of moving the nuclear deterrent away from the densely populated UK and out to sea had considerable appeal in the UK. It not only implicitly addressed the drawbacks of Blue Streak in that it was not vulnerable to a pre-emptive nuclear strike, but invoked the traditional role of the Royal Navy, and its second-strike capability made it a more credible deterrent. In February 1958, Mountbatten created a working party to examine the effectiveness, cost and development time of Polaris compared with that of Blue Streak and the V-bomber force. The working party indeed saw clear advantages in Polaris. At this point, the Minister of Defence, Duncan Sandys, requested a paper on Polaris, and was given one that strongly argued the case for Polaris. Sandys was cautious about Polaris, as it was still under development, so its costs were uncertain. The Air Ministry was understandably alarmed, circulating a paper that refuted the Admiralty's position point by point, attacking Polaris as having the same striking power but having less accuracy and a smaller warhead than Blue Streak, at 20 times the cost. The US Navy had already polished the counter-arguments, noting that second strike weapons only had to target cities, for which Polaris warhead's size and accuracy were adequate. Moreover, it was noted that while the missile was limited in range, the submarine could roam the oceans, and could attack China, for example.
Negotiations
With the cancellation of Blue Streak in the air, the British Nuclear Deterrent Study Group (BNDSG) produced a study on 23 December 1959 that argued that Polaris was expensive and unproven, and given the time it would take to build the boats, could not be deployed before the early 1970s. The Chiefs of Staff Committee therefore recommended the purchase of the American Skybolt, an air-launched ballistic missile, with Polaris as a possible successor in the 1970s. The British government decided to cancel Blue Streak if it could acquire Skybolt. The Prime Minister, Harold Macmillan, met with President Dwight Eisenhower at Camp David in March 1960, and arranged to buy Skybolt. In return, the Americans were given permission to base the US Navy's Polaris boats at Holy Loch in Scotland. The financial arrangement was particularly favourable to the UK, as the US was charging only the unit cost of Skybolt, absorbing all the research and development costs. Far from taking this as a defeat, the Royal Navy's planning for the eventual purchase of Polaris was accelerated. A June 1960 paper by the Director General, Weapons, Rear Admiral Michael Le Fanu, recommended that a Polaris project should be created along the same lines as SPO.