| Summary : The site of Royal Air Force Boulmer radar station. It was built to replace the Second World War Ground Controlled Interception station at Northstead (see HOB UID 1478782) as part of the Rotor programme to modernise the United Kingom's radar defences. The station was operational from 1953 and an underground operations bunker was completed in 1954. The station was fitted with a Type 7 Mark 3 radar head for local search and control, two Type 14 (Mark 8 and Mark 9) plan positioning radar heads, four Type 13 Mark 6 and two Type 13 Mark 7 height finder radar heads, and one Type 54 Mark 3 radar head for search and control with no IFF (Identification Friend or Foe). The radar heads were mounted on plinths and 25 feet gantries, apart from the Type 54 that was mounted on a 200 feet tower. The site was equipped with a guardhouse designed to resemble a bungalow with a veranda, which gave access to the two-storey, underground R3 operations block. In 1956 Type 80 Mark 3 was installed at the site and the station was designated a Master Radar Station. In 1957 it took over the role of Sector Operations Centre from RAF Shipton. In 1958 Boulmer was upgraded with Type 84 Surveillance radar and by 1966 was part of the Linesman/Mediator radar network. The site still operates as a modern radar station. The guardhouse still stands at the site and gives access to the bunker. It has been modified and the veranda filled in to create an extra room. The R3 bunker was rebuilt in 1982 and is still in use. New rooms and extensions were added, increasing the structure to almost double its original size. |
More information : The Rotor programme was developed to advance the wartime radar technology in detecting and locating fast-flying jets. It was approved by the Air Council in June 1950. The first stage of the programme, Rotor 1, was to technically restore existing Chain Home, centrimetric early warning, Chain Home Extra Low and Ground Controlled Interception stations and put them under the control of RAF Fighter Command. There were three main components to the Rotor stations: the technical site, including the radars, operation blocks and other installations; the domestic site, where personnel were accommodated; and the stand-by set house, a reserve power supply. The technical site for Boulmer Rotor station was located at NU 240 125. The domestic site and stand-by set house were co-located at NU 242 145.
The two main constructions at Rotor stations were the operations block and guardhouse. Operations blocks were the largest structures built at Rotor stations. They were constructed of reinforced concrete and designed to withstand 2,000lb bombs. The outer walls and roof of the Rotor operations blocks were 3 metres thick and the internal walls between 0.15 to 0.6 metres wide. The exterior was coated with an asphalt damp course and surrounded by a 0.15 metre brick wall. The roof was usually flush with the ground surface and up to 4.34 metres of earth was mounded on top. The operations blocks, identified by a 'R' prefix, contained technical equipment, domestic facilities, workshops and a plant for air conditioning and gas filtration, all within a single complex. Four of the blocks (R1-R4) were underground constructions designed for the more vulnerable sites on the east and south-east coasts. Others were semi-submerged (R6) or above ground (R5, R7-R11) heavily protected structures built to withstand 1000lb bombs. The guardhouses were designed to resemble bungalows. They were single-storey buildings capped with a flat, concrete roof, above which a pitched roof contained water tanks. They were generally constructed of brick, but were built to blend in with the local architectural style. The guardhouse also contained an armoury, store, rest room and lavatories. Those associated with underground operations blocks featured a projecting rear annex that housed a stairwell leading down to an access tunnel. (1-3)
Aerial photography from 1997 shows the main operations block, guardhouse and several masts and aerial plinths surviving at the site. (4)
The Second World War GCI radar station at Northstead was replaced in the early 1950s by a newly-built Rotor station. The Rotor station was constructed close to a wartime airfield, RAF Boulmer. The station was operational from 1953 and the two-storey underground R3 operations bunker was completed in 1954. In 1956 a Type 80 Mark 3 was installed at the site and the station was designated a Master Radar Station. In 1957 it took over the role of Sector Operations Centre from RAF Shipton. In 1958 Boulmer was upgraded with Type 84 Surveillance radar and by 1966 was part of the Linesman/Mediator radar network. The site still operates as a modern radar station. The R3 bunker was rebuilt in 1982. It was converted into two single-level operations rooms, instead of the original two-level operations room. New rooms were added, increasing the the size of the structure to almost double its size. The guardhouse has been modified, but still gives access to the bunker. The veranda has been converted into an extra room.
Type 7 radar was constructed at a remote site to the east of the station on the old airfield. The aerial array was positioned above an underground R7 bunker or 'well'. This contained the transmitter and receiver equipment. The remote site was equipped with its own IFF (Identification Friend or Foe) mounted on a plinth with an accompanying cabin, and a brick-built electricity sub-station. (5) |