Y-stations

Y-stations were British signals intelligence collection sites established during the First World War and used again during the Second World War. The sites were operated by a range of agencies including the Army, Navy and RAF plus the Foreign Office (MI6 and MI5), General Post Office and Marconi Company receiving stations ashore and afloat.

The "Y" stations tended to be of two types, for intercepting of 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, because of the need to minimise interference. The sites collected radio traffic which was then either analysed locally or if encrypted, passed for processing initially to Admiralty Room 40 in London and during World War II to the Government Code and Cypher School at Bletchley Park in Buckinghamshire.

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 and it also acted as a Y station. Many amateur radio (ham) operators supported the work of the Y stations, being enrolled as "Voluntary Interceptors". 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 land lines. The name derived from Wireless Interception (WI). The term was also used for similar stations attached to the India outpost of the Intelligence Corps, the Wireless Experimental Centre (WEC) outside Delhi.

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