The UK’s Nuclear Deterrent
In 1955, Britain began developing a long-range liquid-fuelled missile, the Blue Streak. Designed to deliver nuclear weapons, as part of Britain’s independent nuclear capability, work focused on producing an intermediate range missile. This single stage silo-based missile was intended to have a range of 2,500 miles.
In 1960, however, the Blue Streak programme was scrapped. The British Cabinet Defence Committee were reluctant to spend an addition £600m on top of the £65m already spent for a delivery system that proved to be militarily inadequate after testing.
Post-war Britain’s nuclear weapons armament was initially based on free-fall bombs delivered by the V bomber force. It soon became clear that if Britain wanted to have a credible nuclear deterrent threat, a ballistic missile was essential. There was a political need for an independent deterrent, so that Britain could remain a major world power. Britain was unable to purchase American weapons wholesale due to the restrictions of the Atomic Energy Act of 1946.
In April 1954 the Americans proposed a joint development programme for ballistic missiles. The United States would develop an intercontinental ballistic missile (ICBM) of 5,000-nautical-mile (9,300 km) range (SM-65 Atlas), while the United Kingdom with United States support would develop a medium-range ballistic missile (MRBM) of 2,000-nautical-mile (3,700 km) range. The proposal was accepted as part of the Wilson-Sandys Agreement of August 1954, which provided for collaboration, exchange of information, and mutual planning of development programmes. The decision to develop was influenced by what could be learnt about missile design and development in the US. Initial requirements for the booster were made by the Royal Aircraft Establishment at Farnborough with input on the rocket engine design from the Rocket Propulsion Establishment at Westcott. British Operational Requirement 1139 demanded a rocket of at least 1500 n.m. range and the initially proposed rocket would have just reached that threshold.
The de Havilland Propellers company won the contract to build the missile, which was to be powered by an uprated liquid-fuelled Rocketdyne S3D engine, developed by Rolls-Royce, called RZ.2. Two variants of this engine were developed: the first provided a static thrust of 137,000 lbf (610 kN) and the second (intended for the three stage satellite launch vehicle) 150,000 lbf (670 kN). The engines were unique at that time in that they could be vectored by seven degrees in flight and could therefore be used to guide the vehicle. This configuration, however, put considerable pressure on the autopilot which had to cope with the problem of a vehicle whose weight was diminishing rapidly and that was steered by large engines whose thrust remained more or less constant. Vibration was also a problem, particularly at engine cut-off, and the later development of the autopilot for the satellite launcher was, in itself, a considerable achievement.
The missile used liquid oxygen and kerosene propellants. Whilst the vehicle could be left fully laden with over 20 tonnes of kerosene, the 60 tonnes of liquid oxygen had to be loaded immediately before launch or icing became a problem. Due to this, fuelling the rocket took 4.5 minutes, which would have made it useless as a rapid response to an attack. The missile was vulnerable to a preemptive nuclear strike, launched without warning or in the absence of any heightening of tension sufficient to warrant readying the missile. To negate this problem de Havilland created a stand-by feature. A missile could be held at 30 seconds’ notice to launch for ten hours. As the missiles were to be deployed in pairs and it took ten hours for one missile to be prepared for stand-by, one of the two missiles could always be ready for rapid launch.
To protect the missiles against a preemptive strike while being fuelled, the idea of siting the missiles in underground launchers was developed. These would have been designed to withstand a one megaton blast at a distance of half a mile (800 m) and were a British innovation, subsequently exported to the United States. However, finding sites for these silos proved extremely difficult and RAF Spadeadam in Cumbria was the only site where construction was started on a full scale underground launcher, although test borings were undertaken at a number of other locations.
Doubts arose as the cost escalated from the first tentative figure of £50 million submitted to the Treasury in early 1955, to £300 million in late 1959. Its detractors in the civil service claimed that the programme was crawling along when compared with the speed of development in the US and the Soviet Union. Estimates within the Civil Service for completion of the project ranged from a total spend of £550 million to £1.3 billion, as different ministers were set on either abandoning or continuing the project.
The project was unexpectedly cancelled in April 1960. Whitehall opposition grew, and it was cancelled on the ostensible grounds that it would be too vulnerable to a first-strike attack. Admiral of the Fleet Lord Mountbatten had spent considerable effort arguing that the project should be cancelled at once in favour of the Navy being armed with nuclear weapons, capable of preemptive strike. Some considered the cancellation of Blue Streak to be not only a blow to British military-industrial efforts, but also to Commonwealth ally Australia, which had its own vested interest in the project.
The British military transferred its hopes for a strategic nuclear delivery system to the Anglo-American Skybolt missile, before the project’s cancellation by the United States as its ICBM programme reached maturity. The British instead purchased the Polaris system from the Americans, carried in British-built submarines.