Remains of a Direction Finding (D/F) tower, Ventnor Y-station

Overview

Heritage Category: Listed Building

Grade: II

List Entry Number: 1427450

Date first listed: 26-Oct-2015

Location Description: Located at SZ 54781 77515 in a field on Rew Down, above Ventnor.

Map

Ordnance survey map of Remains of a Direction Finding (D/F) tower, Ventnor Y-station
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Location

Location Description: Located at SZ 54781 77515 in a field on Rew Down, above Ventnor.

The building or site itself may lie within the boundary of more than one authority.

District: Isle of Wight (Unitary Authority)

Parish: Ventnor

National Grid Reference: SZ5478177515

Summary

The remains of a Direction Finding (D/F) tower, Ventnor Y-station, c1942, comprising a protective polygonal brick wall, a concrete floor pad within it with the polygonal foundations for the wooden tower (now demolished) and concrete pads for the tower supports (also now gone).

Reasons for Designation

The remains of a D/F (Direction Finding) tower, Ventnor Y-station, circa 1942, is listed at Grade II for the following principal reasons: * Historic interest: representative of the highly significant role of Second World War Y-stations in being the ‘ears’ of Bletchley Park: RN Y-stations intercepted German naval traffic and were highly likely to have been responsible for intercepts which resulted in the breaking of the Naval Enigma code; * Rarity: although acknowledging that there has been no national study of the survival of D/F towers, on current evidence this appears to be one of the best preserved Y-station D/F towers nationally and one of possibly only two Royal Navy examples known to retain its blast wall; * Fabric: the remains of the D/F tower survive well and are legible despite the inevitable loss of the wooden tower (of which there are no known in-situ examples nationally), and includes the octagonal base for the tower, bases for the tower props and a blast wall, which unusually has defensive loopholes within it.

History

Signals Intelligence (known as SIGINT) played a critical role during the Second World War. The contribution of Bletchley Park - headquarters of the Government Code and Cypher School (GC&CS) - and its code breakers to the war effort is of global renown. Much less well understood is the role of the Y-Service, an inter-service intelligence gathering collaboration with each service (RAF, Army, Navy, Foreign Office and GPO) tracking activity in its enemy counterpart (a further arms-length service was the Radio Security Service monitoring illicit wireless stations). With its origins in the First World War, during the Second World War the Y-Service consisted of a chain of wireless interceptor stations, known as Y-stations, which were distributed around the country, sometimes in elevated positions, sometimes on the coast as at Ventnor. These comprised both fixed receiving stations and/or Direction Finding (D/F) capabilities (Ventnor had both.) The Y-station operators were critical in intercepting enemy transmissions, identifying the locations of enemy ships and aircraft and passing this information back to their home station and to Bletchley Park (known as Station X) to be deciphered and translated. Y-stations were more usually but not exclusively manned by women, some chosen for their language skills, others with experience in Morse code. Pether put it ‘Throughout the Second World War the ‘Y’ Service was the ‘’ears’’ of the G.C.& C.S. at Bletchley Park’ (2011, 3); without the Y-service’s interceptions GC&CS could not have functioned as its codebreakers and analysts would have had nothing to work with.

The Y-Service reported to GC&CS which, through its Y-Committee, co-ordinated the inter-ministry collection of information. The Royal Navy’s Y-service gained intelligence from German naval radio traffic and also to gain a positional fix on vessels in convoys, blockade runners, U-boats (German submarines) and E-boats (German fast torpedo boats). Naval Y-stations were manned by Special Duties Wrens.

Y-stations across the services took a variety of physical forms, as a Y-station was really a means of gathering SIGINT rather than a building type. However, there was some commonality of form for D/F towers across the services even if they might have been gathering different types of information (and indeed the presence of a D/F tower does not necessarily imply that a site is a Y-station).

The total number of Y-stations built in England is difficult to establish. Pether (2011, 17-20) maps 56 across the services, 11 being Royal Navy stations, but this figure is certainly too low; Ventnor, for example is not listed.

At Ventnor a Royal Navy Signal Station was based at ‘The Heights’ hotel, formerly on the Whitwell Road below the D/F tower but since demolished. The Y-station, which was the sole such on the Isle of Wight, was responsible for gathering information from VHF and non-Morse radio-telephony interception from German naval vessels, principally E-boats. Information received was passed to the Intelligence Centre of the Combined Operations HQ, Fort Southwick, Portsdown (Portsmouth), to HMS Flowerdown (near Winchester) or to Bletchley Park as appropriate. Originally the station did not have direction finding capabilities (i.e. the ability to fix the position and bearing of an enemy vessel) but this was added at Ventnor soon after the station was established in the form of a D/F tower on Rew Down. The date of construction is not known but was probably spring/early summer 1942 as the tower is mentioned by a Wren stationed at Ventnor before the Dieppe Raid of August 1942 (Page, op cit 36). A shadow cast by the tower can be seen on a Luftwaffe aerial photograph dated 15th August 1943 (IOW Historic Environment Record) but other than on aerial photographs no images of the tower in situ are known. Photographs of other examples, surviving plans for D/F towers and the length of the shadow cast on aerial photographs at Ventnor would all suggest that this was a substantial structure in the region of 30 feet (c9m) tall. The tower was sometimes manned by a solitary and armed Wren (Page op cit, 36) but manning of D/F towers was variable; teams of two plus a supervisor was perhaps more common. The brick enclosure wall would have served as a blast wall to protect the base of the tower and also for small arms defence, given its loopholes.

In July 1944 the D/F tower and several houses on Whitwell Road were damaged by a V1 ‘doodlebug’ rocket which exploded close to the tower having flown off target (it is believed to have been destined for Southampton or Portsmouth). According to the HER ‘the tower was rocked by the explosion and may have been partially demolished but it is not known whether any operators were injured. The timber buttresses certainly seemed to have been pulled from their sockets in the ground as, when the tower was repaired or replaced shortly afterwards, new timbers were installed.’ Lists of Y-stations in the National Archives (references WO 199/66 and HW 41/401) indicate that Ventnor had been removed, and therefore was presumably no longer operational, by 28th September 1944. However, the tower was still extant and visible on an aerial photograph dated 24th January 1948, which might suggest some repairs had been made and a continuation of use in some form, but had been demolished by November 1949 when it is no longer visible on a further aerial photo.

Details

The remains of a D/F (Direction Finding) tower, Ventnor Y-station, c1942, comprising a protective brick wall, a concrete floor pad within it (the foundations for the wooden tower, now demolished), and concrete pads for the tower supports (also now gone).

MATERIALS: red brick for the protective wall; the floor pad and tower foundations are of concrete as are the external tower support pads.

PLAN: an octagonal structure.

DESCRIPTION: the D/F tower’s octagonal red brick wall is in English bond capped with a soldier course with iron fixings. Set into the hill slope on Rew Down above Ventnor Bay, the wall is therefore of varying height but rises to a maximum of approximately 2m 25cm and is 36cm wide. The overall enclosure is circa 5m 40 in width. Seven sides contain loop holes for small arms, those on the upslope (north) side being higher up the wall. The eighth side, to the south-east, provides access to the interior. Here is a concrete floor pad with a gutter running around the internal face of the brick wall. In the centre of the pad is a recessed octagonal concrete platform, approximately 3m 90cm in diameter, with dwarf walls 15cm wide and some surviving iron fixings. This would have formed the foundation for the wooden tower (demolished). A cable-trench (63cm wide) runs through its centre on a west-east axis.

Evenly distributed around the outside of the brick enclosure are seven concrete pads with one or two rectangular slots cut into them; these were the bases for wooden struts to support the tower.

Sources

Books and journals
Lake, J, Bletchley Park Conservation Management Plan, (2004)
Page, G (Editor), They Listened in Secret, (2003), 36, 57, 82, 144, 176-189
Pether, J, Funkers & Sparkers: Origins & Formation of the ''Y'' Service, (2011)
Websites
Extract from Bletchley Park website on Y-stations, accessed 21st August 2014 and 19th August 2015 from www.bletchleypark.org.uk/content/hist/worldwartwo/
Other
Isle of Wight County Archaeology and Historic Environment Service, HER record reference 3232 – MIW4747
Select aerial photographs in the National Monuments Record – RAF/CPE/UK/2431, frames 3049 & 3050 (January 1948); RAF/541/381, 3041, 3042 & 3043; RAF 30100 (originally 541/245), PO-0022, PO-0023, PO-0024, & PO-0025.

End of official listing