Chevaline - Polaris SLBM upgrade

Chevaline, a name that appeared out of the blue in 1979. Chevaline was a project to improve the capability of the Polaris system, while maintaining a nuclear weapons design team in the UK. The Chevaline project was started soon after the Labour government took power in 1964 and continued until the late 1980s, entering service in 1982. Originally called "Super Antelope", it was revealed by the incoming Tory Government in 1979, who while embarking on the Trident programme, opted to further upgrade Chevaline with improved decoys and penetration aids.

By upgrading the penetration aids of the Polaris A2 to produce the A3TK the UK was able to field a "credible deterrent" capable of tackling targets such as Moscow, which was protected by the "Galosh" ABM system. One of the decoys for Chevaline was called Impala, but was never deployed. In the event Chevaline was the only ballistic missile to employ decoys. Much of the work on Chevaline remains classified, but there are consistent rumours that an official history is being written.

When Polaris was superseded by Trident in the 1990s, some Polaris missiles were donated to museums. The example shown here is displayed in the Museum of Flight at East Fortune.

The photos below show the interior of the Chevaline warhead bus known as the Penetration Aid Carrier (PAC). This is shown minus the re-entry vehicles that would fit in the recesses in the bus. Note the small rocket motors in the nose for maneuvering the bus. The PAC was described as a mini spacecraft in its own right, capable of maneuvering in its own right and deploying decoys and chaff. The PAC in the photos is on display at the Bristol Collection at RAF Kemble.

 Return to Guided Weapons