British signals intelligence collection sites during WW1 and WW2
The "Y" service was a network of British
signals intelligence collection sites, the Y-stations. The service was established during the First World War and used again during the Second World War.[1] The sites were operated by a range of agencies including the
Army,
Navy and
RAF, and the
Foreign Office (
MI6 and
MI5). The
General Post Office and the
Marconi Company provided some receiving stations, ashore and afloat. There were more than 600 receiving sets in use at Y-stations during the Second World War.[2]
Role
Arkley View, 1943
The "Y" name derived from Wireless Interception (WI).[3] The stations tended to be one of two types, for intercepting the signals and for identifying where they were coming from. Sometimes both functions were operated at the same site, with the
direction finding (D/F) hut being a few hundred metres from the main interception building to minimise interference. The sites collected radio traffic which was then either analysed locally or, if
encrypted, passed for processing initially to the
AdmiraltyRoom 40 in London and then during World War II to the
Government Code and Cypher School at
Bletchley Park in Buckinghamshire.[4]
In the Second World War a large house called "Arkley View" on the outskirts of
Barnet (now part of the
London Borough of Barnet) acted as a data collection centre, where traffic was collated and passed to Bletchley Park; it also housed a Y station.[5] Much of the traffic intercepted by the Y stations was recorded by hand and sent to Bletchley by motorcycle couriers, and later by
teleprinter over Post Office
landlines.[6] Many
amateur radio operators supported the work of the Y stations, being enrolled as "Voluntary Interceptors".[7]
The term was also used for similar stations attached to the India outpost of the Intelligence Corps, the
Wireless Experimental Centre (WEC) outside
Delhi.[8]
Direction-finding Y stations
Specially constructed Y stations undertook
high-frequency direction finding (D/F) of wireless transmissions. This became particularly important in the
Battle of the Atlantic where locating
U-boats was vital.
Admiral Dönitz told his commanders that they could not be located if they limited their wireless transmissions to under 30 seconds, but skilled D/F operators were able to locate the origin of their signals in as few as six seconds.[9]
The design of land-based D/F stations preferred by the
Allies during the Second World War was the
U-Adcock system, where a small operators' hut was surrounded by four 10 ft-high (3.0 m) vertical aerial poles, usually placed at the
points of the compass. Aerial feeders ran underground, surfaced in the centre of the hut and were connected to a direction finding
goniometer and a wireless receiver, that allowed the bearing of the signal source to be measured. In the UK some operators were located in an underground metal tank. These stations were usually in remote places, often in the middle of farmers' fields. Traces of Second World War D/F stations can be seen as circles in the fields surrounding the village of
Goonhavern in Cornwall.[10]
Y station sites in Britain
The National HRO communication receiver was extensively used by the
RSS and Y service
^Nicholls, J., (2000) England Needs You: The Story of Beaumanor Y Station World War II Cheam, published by Joan Nicholls
^R.B. Sturtevant, AD7IL (December 2013). "The Secret Listeners of 'Box 25, Barnet'". Popular Communications. 32 (4). CQ Communications, Inc: 22–26.
ISSN0733-3315.{{
cite journal}}: CS1 maint: numeric names: authors list (
link)
^Aldrich, Richard James (2000), Intelligence and the War Against Japan: Britain, America and the Politics of Secret Service, Cambridge University Press
^"Listening to the enemy"(PDF). Ventnor and District Local History Society. Retrieved 12 February 2024.
^Friedman, William F. (11–20 August 1943).
Report on E operations at BP (Report). Government Code and Cypher School: Directorate: Second World War Policy Papers. HW 14/85 – via The National Archives.
Kenyon, David (10 May 2019), Bletchley Park and D-Day: The Untold Story of How the Battle for Normandy Was Won, Yale University Press,
ISBN978-0-300-24357-4
Further reading
Macksey, Kenneth (2003). The Searchers: Radio Intercept in Two World Wars. London: Cassell.
ISBN0-304-36545-9.