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Raf Ventnor

Hob Uid: 1306901
Location :
Isle of Wight
Ventnor, Wroxall
Grid Ref : SZ5688707848
Summary : A Second World War Chain Home radar station, later updated in the early 1950s as part of the Rotor programme to upgrade the United Kingdom's radar defences. The station, established in 1938, provided early warning of enemy aircraft approaching the South coast during the Second World War- it was especially important during the Battle of Britain. Because of this it was one of the radar stations attacked by the Luftwaffe on "Adlertag". It was originally equipped as a Type 1 station with four steel pylons (transmitting masts) and four wooden (receiver) masts, these were later reduced to three of each. In 1940 a protected underground operations room was added. Later during the war a Type 271 Chain Home Extra Low station was also established on the site and by the end of the war radar Types 16, 24, 52 and 53 had also been added. The station was reduced to care and maintenance shortly after the war. In the early 1950s the station was reactivated and by circa 1952 had been remodelled as a Centimetric Early Warning (CEW) station. Rotor technical sites comprised radar arrays, a small electrical substation, an operations building and a guardhouse, and were linked by roads and tracks. Ventnor mounted two Type 14 (Mark 8 and 9) plan positioning radar heads and three Type 13 (2x Mark 6, 1x Mark 7) height finder radar heads on plinths and 25 feet gantries. The site featured a guardhouse designed to resemble a bungalow, which gave access to a single-storey, underground R1 operations block. The Royal Air Force decommissioned the site in 1961 and it was used by the Civil Aviation Authority (CAA) as a communications station. The guardhouse, air vents and emergency staircase of the operations bunker were later demolished and the bunker was eventually sealed shut in 2004. Surviving surface features at the site include the Second World War Operations Room, mast bases, a Type 80 radar modulator building, CAA Building, two Marconi Type 264A radar plinths, and ancillary structures.
More information : SZ 569 785. The Radar Station at Ventnor was established in 1938 as part of the Chain Home radar network to warn of the approach of hostile aircraft from the continent. As one of the original twenty Chain Home stations it played an important part in the Battle of Britain, and was itself attacked by the Luftwaffe dive bombers in August 1940. Throughout the war, it fulfilled a vital role detecting aircraft crossing the channel, and from June 1944 incoming V1 flying bombs.

It was originally equipped as a Chain Home or Type 1 station with four steel pylons (transmitting masts) and four wooden (receiver) masts, these were later reduced to three of each. In 1940 a protected underground operations room was added. During the war a Type 271 Chain Home Extra Low station was also established on the site and by the end of the war radar Types 16, 24, 52 and 53 had also been added.

After the end of the war it was one of the radar stations retained within the 'defended area' and in 1947 was designated a Chain Home Low station. In the late 1940s a scheme known as Rotor was begun to upgrade Britain's radar defences, this involved the refurbishment and upgrading of wartime radar types and construction of new protected accommodation. At Ventnor a single level underground bunker, known as an R1, was built and a, now demolished, bungalow-like guardroom. In December 1953, it was equipped with the following radar, one Type 14 Mk9, one Type 14 Mk8, two Type 13 Mk6, and one Type 13 Mk7. Ventnor was classified as a Chain Home (CH) (East) and Centrimetric Early Warning Station (CEW) with the station code OJC.

Under the Rotor 2 scheme, started in 1954, Ventnor was to be equipped witha powerful Type 80 radar, and by the end of 1956, one of the first five Type 80 Mk1 radars was in place at Ventnor. In the late 1950s a joint military/civil radar system was proposed Plan Ahead/Linesman, the civilian part later becoming known as Mediator. Under this scheme, in the early 1960s two Marconi Type 264A radars and a Secondary Surveillance radar were installed at Ventnor. A multi-carrier VHF radio station was also installed at this date.

The Radar Station, which lies within a fenced enclosure, occupies the crest of Bonchurch Down, the highest point on the Isle of Wight, overlooking Bonchurch, a suburb of Ventnor. Outside of the perimeter fence, at its northwest corner is an unusual triangular shapeed pillbox, three other small brick structures in this area probably formerly housed electrical switch gear. At the western end of the enclosure is the protected Second World War operations room and to its rear a small brick building, also at this end of the compound are two modern radio masts. The main entrance into the site is througha pair of double gates on the northern perimeter, a track then leads to the still active Civil Aviation Authority (CAA) building, probably erected during the early 1960s. Close to this is a single wooden radio mast, which may be the remains of a truncated Second World War Chain Home receiver mast. To its east are two circular brick plinths for Marconi Type 264 A radars, the western one of which retains its head, closeby is a standby set house. Also in this area is the 1950s Type 80 radar modulator building. Concrete floor slabs indicate the position of other buildings.

The site is now operated by the CAA as a radio station.

The field investigation comprised a perambulation around the exterior of the fenced enclosure. (1-5)

A Chain Home radar station at Ventnor (SZ 567 784) established by 18-APR-1941. (6)

A Chain Home radar station at Ventnor. Aerial photography from 1999 shows that the receiver block survives in reasonable condition at SZ 567 784, surrounded by three sets of aerial bases. The base of the transmission block is located at 570 785, surrounded by 1-2 aerial bases. The layout of the original site follows present trackways. Two ancillary structures are located at 5670 7854, while two buildings located at 572 789 and 564 785 have since been removed, however the bases may survive under scrub. Of the later Rotor station, the operations block is visible as a mound with parch marks on top indicating near-ground cabling. The guardhouse is now demolished and the entrance to the operations bunker is capped with a large concrete area. Two to three aerial bases also remain alongside the track layout of the base. The remainder of the site is derelict Second World War material with a modern communications unit in the centre. (7)

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 at Ventnor Rotor station was located at SZ 565 784. The domestic site and the stand-by set house were co-located at SZ 553 782.

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. 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 guard rooms 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. (8-10)

As source 7. (11)

RAF Ventnor was an original Chain Home station authorised in 1937. It continued in use until shortly after the Second World War when it was placed into care and maintenance. The Chain Home station was re-established in the early 1950s as part of Phase 1 of the Rotor programme and later included in Phase 2, when a Centimetric Early Warning (CEW) station was constructed with a projected completion date of November 1952. Ventnor CEW station was operational until at least 1957, but was eventually closed and placed under care and maintenance. The Royal Air Force decommissioned the site in 1961 and it was taken over by the Ministry of Aviation for use as a radar and communications station for the Civil Aviation Authority (CAA). It was also used as a radar test location. The operations bunker was not used by the CAA and in 1962 it was refurbished as the Isle of Wight County Control Centre. This remained operational until 1991 as the Isle of Wight Emergency Centre. The guardhouse, air vents and emergency staircase were all demolished, and the bunker was eventually sealed shut in 2004. (12)

RAF Ventnor was a chain home station that provided long range early warning for the south coast of England, especially for Southampton and Portsmouth. It was an important part of the country's defences during the Battle of Britain, particularly for 11 Group Royal Air Force Fighter Command. (13)

During the Battle of Britain, the chain home station at Ventnor was attacked and bombed by the Luftwaffe in their all-out air assault codenamed 'Adlertag' or 'Eagle Day' launched on 13th August 1940. (14)

One of the steel pylons was dismantled in 1941 and rebuilt on a Scottish Island. There were four wooden towers until 1947 when one was destroyed when a Channel Islands mail plane crashed into it. The remaining towers were dismantled in 1957. (15)

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Source Number : 1
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Source details : Wayne D Cocroft/27-Feb-2000/EH Cold War Project
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Source details : Gough J 1993 Watching the Skies HMSO 25, 27, 55, 57-8.
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Source details : Subterranea Britannica, 2004. RAF Ventnor <> Updated 11-DEC-2004 [Accessed on 13-JAN-2009]
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Source Number : 13
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Source details : Royal Air Force. Crown Copyright 2005. 'Battle of Britain: 11 Group' <> [Accessed 14-JUL-2010]
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Source details : Email correspondence 31-MAR-2015
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Source details : Dobinson C S 1998 Twentieth century fortifications in England vol XI.2 RThe Cold War CBA 151, 155
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Source details : Bray P, no date: 'Radar at Ventnor 1939-45' Ventnor and District Local History Society
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Source details : Latham C and Stobbs A, 1996: 'Radar a wartime miracle', Sutton Publishing; 210, 223
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Monument Types:
Monument Period Name : Mid 20th Century
Display Date : Built in 1938
Monument End Date :
Monument Start Date : 1938
Monument Type : Radar Station, Chain Home Station, Early Warning Station
Evidence : Documentary Evidence, Extant Building
Monument Period Name : Mid 20th Century
Display Date : Remodelled in early 1950s
Monument End Date : 1953
Monument Start Date : 1950
Monument Type : Radar Station, Operations Block, Guardhouse
Evidence : Extant Building, Subterranean Feature, Demolished Building
Monument Period Name : Second World War
Display Date : Second World War
Monument End Date : 1945
Monument Start Date : 1939
Monument Type : Chain Home Station, Radar Station, Early Warning Station
Evidence : Building, Extant Building

Components and Objects:
Related Records from other datasets:
External Cross Reference Source : DoB Non Anti Invasion Database UID
External Cross Reference Number : 2961
External Cross Reference Notes :
External Cross Reference Source : National Monuments Record Number
External Cross Reference Number : SZ 57 NE 123
External Cross Reference Notes :

Related Warden Records :
Associated Monuments :
Relationship type :
Associated Monuments :
Relationship type : General association
Associated Monuments :
Relationship type : General association

Related Activities :
Associated Activities :
Activity type : MEASURED SURVEY
Start Date : 1995-04-01
End Date : 2002-03-01
Associated Activities :
Activity type : MEASURED SURVEY
Start Date : 2008-01-01
End Date : 2009-12-31