Arkley View - Secret Listeners

The Radio Security Service Expands & Becomes Recognised

Owing to air raids and the need to expand it became apparent that Wormwood Scrubs was not ideal and M.I.5 moved out to various other sites. The RSS was taken over by M.I.6 or Secret Intelligence Service (SIS) as it was widely known. A sub-section of M.I.6 was taken over by Brigadier Gambier Parry and labelled Section VIII. This was further divided into Special Communication Units (SCU) and the two dealt with here were SCU3 and SCU4 The RSS moved on October 3rd 1940 into new headquarters at Arkley View, within a large site 2 miles north of Barnet. This building was already being used by the Post Office as an intercept station. The ‘View’ housed the analysis, intelligence, direction finding control and various administrative departments.

Huts were erected in the grounds for intercept work, a teleprinting terminal, and later the ever-expanding departments to identify, classify and collate the enormous secret intelligence enemy radio networks. The secret cryptic address became well known to the select as PO Box 25 Barnet, this being the new postal address for V.I.s. Arkley View was on the right of Barnet Road leading to Stirling Corner. Arkley Lane had the View on its left and Oaklands to its right. Here was accommodated the orderly room and the despatch riders’ base for taking intercepted messages to Bletchley Park. Officers’ and sergeants’ messes were in Scotswood opposite the View. Other large houses such as Rowley Lodge, The Lawns and Meadowbank were used as billets, messing, transmitting and training schools. In Ravenscroft Park, High Barnet, a billet, operators’ evaluation and a small intercept training station were established, run by CQMS Soames (later transferred to the Lawns).

Arkley Organisation

The large country house, Arkley View, was known to all SCU3 enlistments, as the induction to this branch of M.I.6 invariably took place here. Enrolled initially by Lord Sandhurst, soon to be followed by Captain (later Major) Bellringer, a short black-moustached officer, recruits took the oath and the King’s shilling, which is where the resemblance to the generally understood army finished. The account of one early enlistment can be read here. A ‘normal’ army enlistment was provided with an Army Book 64 (AB64) parts I and II. Part I contained such personal details as date of birth, service number, rank with promotion dates (if any) and the date when various chemicals were injected to protect the recipient from all the various bugs which arose from service to one’s country. This concern for his welfare was followed by details of his next-of-kin and an invitation to write his will, (acceptable without a witness). However SCU prospective soldiers did not receive AB64 part II because this gave a record of pay which in this case did not come from Army funds but from the Foreign Office. This presented a problem for overseas postings which was solved by issuing part II and paying the army rate at the usual pay parade. The recipient was required to open a bank account at home to accept the balance of his RSS-enhanced pay.

Lt Colonel Morton Evans (amateur licence GW5KJ) was made Deputy Controller of the RSS and served as officer i/c at Arkley from 1941 to 1946

Under Lt Colonel Morton Evans the various departments were mainly located in one-storey buildings each about 100 feet long, at the rear of Arkley View house. These were called huts and were frequently extended, as the need arose, in a similar manner to Bletchley Park. Under the general heading of Discrimination were the departments General Search, Groups, Collation and Allocation. Reports from interceptors came to Arkley where, after processing as explained below, copies of the same messages from different intercepts were compared to enable a good copy to be forwarded to Bletchley Park. Initially the intercepted messages came in from the VIs, working at home in complete secrecy and using whatever time was available. Many had full-time employment but others who were retired or disabled could devote more time to listening on the receivers that they had previously used as Radio Amateurs. At Arkley it was realised that for full coverage of the ever expanding German secret networks some form of 24 hour watch was required and in different parts of the UK in order to maximise the amount of information we could obtain. More details follow later.

General Search

The principal work was the scrutiny of logs and the placing of the intercepted messages in the relevant groups. Box 25 received a thousand or more log sheets daily from V.I.s and the full-time interceptors. These had to be examined to identify new Abwehr services and to sort the familiar ones into their allotted groups. More than 14 different groups had been identified, each having a number of services from perhaps a dozen to a hundred or so. Hence if General Search labelled a message 2/153 it would mean group 2, usually Berlin, and service 153 which could be a link to, say, Madrid, Oslo or Milan. The identification was by means of time, frequency, type of procedure (or preamble if there was a message) or possibly the call sign. This latter was problematic as often call signs changed daily. One task was to examine logs for intercepts which had not been positively identified and to try to discover where to place them or even if they were wanted by us at all. If the operator sent us a previously identified station we sent the details to the relevant Group Officer, located in the next hut, who would then advise the operator whether it was ‘already covered thanks’ or ‘still wanted’. He would have from two to a dozen staff according to the group size. A large wall map was kept in the ‘Group’ hut with coloured wool stretched between points showing the location and working of the various stations. To prevent a casual visitor from seeing the extent of our discoveries, this map was covered with a curtain which was activated by an electric motor. No doubt the local wool shop did not ask questions. If it had, there would have been a ready misleading answer. Log sheets were stamped as ‘suspect’, ‘watch please’ or ‘unwanted’ if due to be returned to the interceptor. If the signal was not the enemy secret service we used the ‘unwanted’ stamp. Other stamps were: ‘unwanted Hun’, ’more please’ and ‘OK covered thanks’. Typically the transmissions in which we were interested looked radio-amateur style as the photograph shows.

This log shows Ham chat such as sri, pse call, nw, 73 (73 is Ham Chat for Kind Regards) but QSA not QSA0 and QRX but not QRX NEXT were used by amateurs. and certainly not a three letter call sign such as CZE and – horrors – sending five letter blocks of code. Any kind of code was strictly forbidden for amateurs. So there was no doubt about CZE and URK being something unusual.

It was important to find out who was ‘working’ whom. As the frequencies and call signs were constantly changing the only common factor was time and possibly operating procedure. Types of preamble and times and frequencies had to be memorised by the staff, who used card indexes for reference. This work could be tedious and tiring as hundreds of log sheets were scrutinised for the brief suspect transmission.

Expansion To 24 Hour 7 Day Intercepting

It became apparent, quite early on, that VIs could not cover all that was required to understand the Abwehr and to penetrate the German secret intelligence networks. Full-time operators working eight hour shifts were required and purpose-built large huts were equipped with the American first class HRO receivers .

Five or six larger stations were spread widely over the UK with up to 32 receiving positions, each with two HROs: two HROs because it could be possible to listen to both ends of a contact. Sometimes a few other types were to be seen such as the AR88 or the British Eddystone and Marconi models. Barnet, Hanslope and St Erth (shown here)

These were working by 1942 and other large stations were at Forfar and Thurso in Scotland and Gilnahirk in Northern Ireland. The operators were recruited from several sources although mainly from the ranks of VIs. Later intercept stations were installed in the Middle East and Gibraltar.

Identifying The Vast German Network

Gradually about 14 separate groups covering different areas were identified. Group 2 was by far the largest and with its centre near Berlin had links (known to us as services) extending over Europe and beyond and was the mainstay of the Abwehr. We designated them as 2/141, or 8/254 for example where the group came first and then our number reference for the service. An officer, with a staff proportionate to the size of the group, was responsible for keeping the record up to date and issuing daily amendments, as the services frequently changed and grew. When messages had been checked for mistakes and omissions, by comparison with other copies, they were sent to Bletchley Park for de-ciphering. It was important for this purpose that the ‘group’ was identified, for instance groups 1 and 6 were naval intelligence. Group 2 had links with other centres or sub groups such as group 5 in Prague, 7 in Vienna and 8 in Italy. Group 3 was the infamous SD under Himmler so we may guess at what some of their traffic revealed. To build up a complete picture of the enemy networks it was vital that we found the location of each transmitter. We therefore relied heavily on the nine or so direction-finding stations which were distributed as widely as possible over the UK. For more information see the Direction Finding (D/F) link. These were working by 1942 and other large stations were at Forfar and Thurso in Scotland and Gilnahirk in Northern Ireland. The operators were recruited from several sources although mainly from the ranks of VIs. Later intercept stations were installed in the Middle East and Gibraltar.

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