(Source: Eastbourne Herald)
Much has been written about Bletchley Park and the decoding of German Enigma signals. However, the code breakers first needed the raw material – transcripts of enemy messages.
The British Y Service was the ‘ears’ of Bletchley Park and without this, code breaking was impossible. There were several departments under the control of MI-8. The RAF, Army, Navy, Metropolitan Police, Post Office and Foreign Office had interceptors and American units also contributed. Haystoun House in Church Street, Willingdon – today flats and previously an old people’s home – was the base of the American 129th Signal Radio Intelligence Company. In the 1940s it stood alone with space for the so-called ‘aerial farm’ – 40 aerials in the form of inverted L’s, 20 on each side of the house.
These were fed to a ‘set room’ that could cater for 42 receivers. Tables around walls had partitions to separate operating positions. Operators kept four-hour watches, known as ‘tricks’ and searchers tuned over a segment of the short wave spectrum listening for any new stations that might pop up. Experienced operators were able to recognise the Morse styles – the so-called ‘fists’ – of individual German signallers. Message pads were ferried by dispatch rider to London. Operators were trained at Camp Crowder in Missouri where they learnt to copy high-speed Morse onto a typewriter. However, a pencil and message pad proved easier because receivers drifted off frequency and one hand was needed to re-tune. The daily schedule was 15 sets at night and 25 during the day.[…]