RAF Bolt Head grass airfield and the RAF Hope Cove Ground Control Intercept (GCI) Chain Home radar station were established in different phases during World War Two, sometime between 1941 and 1942. The grass airfield provided support to RAF Exeter until it was decommissioned in 1947, though the GCI was upgraded as part of the nationwide ROTOR programme and continued to be operational until 1957. GCI stations were developed from late 1940 to assist in the tracking and interception of hostile aircraft after they crossed the coast, particularly at night. The original Chain Home (CH) radar system was strung out along the coast and the tracks of enemy aircraft were lost as they headed inland. GCI stations were designed to counter this problem by tracking hostile aircraft as they passed inland and then directing local fighter squadrons to attack the intruders.
In the early 1950s the site was upgraded as part of the ambitious government ROTOR programme to modernise the United Kingdom’s radar defences. The ROTOR technical sites comprised of radar arrays, an electrical substation, an operations building and communication roads and tracks. Hope Cove was fitted with the following equipment:
- One Type 7 Mark 2 radar head for local search and control,
- three Type 14 (1x Mark 8 and 2x Mark 9) plan positioning radar heads,
- four Type 13 Mark 6 and two Type 13 Mark 7 height finder radar heads,
- one Type 54 Mark 3 radar head for search and control with no IFF (Identification Friend or Foe).
The station was equipped with a guardhouse designed to resemble a bungalow (since demolished) and a two-storey, semi-sunken R6 operations block. It was one of five stations equipped with an R6 bunker, the others being at Hack Green, Cheshire; Langtoft, Lincolnshire; Treleaver, Cornwall and one in Wales at St Twynells, Pembrokeshire.
The ROTOR period radar stations were of five principal types: Centrimetric Early Warning (CEW), Chain Home (CH), Chain Home Extra Low (CHEL), Ground Control Intercept (GCI) and the Sector Operation Centres (SOC). These were distinguished mainly according to the type of radar used (although the SOCs did not have their own radar installations). The station at Hope Cove was GCI, and the operations blocks was an R6 bunker, which was a two-storey, semi-sunken hardened bunker. The semi-underground bunker is spread over roughly 3000 square meters over two floors, each floor has approximately 28 rooms, some of which have been extended with a mezzanine floor. As part of the upgrade to the ROTOR system, Rotor 2, the Type 80, or ‘Green Garlic’, radar was intended to be introduced to the Hope Cove facility in the mid 1950s, and although the modulator building was built, the radar head wasn’t installed.
In 1957, after a period of use by the RAF and the reduction in the ROTOR System due to technological evolution, the station at Hope Cove was taken over by the Home Office. This was part of the home office initiative to provide a dispersed government in the event of war, the bunker was turned into a Regional Seat of Government (RSG), codenamed Gull Perch. It later became a Sub-Regional Control, Sub-Regional Headquarters and Regional Government Headquarters under various Home Office schemes. Surface features surviving at the site include the R6 bunker and a Type 80 radar modulator building. The site was operational until 1992 and then sold in late 1990s. In 2015 it received a grade II listing and is in the process of being converted to other uses.
Source: Historic England