Radio Secret Security Service

Radio Secret Security Service

Amateurs Recruited For Secret Work

Amateur radio enthusiasts – ‘hams’ – played a major role in the secret wireless intelligence war between 1939 and 1945, providing Bletchley Park with vital Morse messages that enabled the codebreakers to read German signals. They were known as Voluntary Interceptors or ‘VIs’ and around 1,200 were recruited. Some of them had powers to enter premises where they thought illicit wireless activity was going on. When World War Two began, all radio amateurs had to hand in their transmitters but were able to keep their receivers, subsequently used by the RSS to listen in to enemy wireless traffic in their own homes or even the garden shed!

At its peak the RSS had an establishment of 2,094, comprising 98 officers, 1,317 operators, 83 engineers and 471 administrative personnel and 125 civilian clerks, plus the 1,200 amateur radio Voluntary Interceptors.During the war 268,000 RSS decrypts were issued by Bletchley Park, with a peak of 282 a day in May 1944. Of these 97,000 were in Abwehr hand cipher and 140,000 enciphered on the Enigma machine. The Nazi Security Service – the SD – produced 13,000 decrypts.

"Enthusiastic Amateurs Of Unimpeachable Discretion"

The need for a specialist organisation to intercept illicit transmissions from the UK was recognised as early as 1928. Wireless, it could be seen, would be a major factor in any future war. It was recommended that the War Office should use voluntary and unpaid “enthusiastic amateurs of unimpeachable discretion” to develop such an organisation. In 1933 the idea of an organisation that eventually became the RSS began to take hold.

In 1939, many “hams” were called up into the RAF Civilian Wireless Reserve – later the RAF Volunteer Reserve – the Territorial Army Signals Unit and the Royal Navy Volunteer (Wireless) Reserve. In those days, in order to obtain a license to operate, radio amateurs had to show proficiency in Morse code, and this made them especially valuable to the new organisations being set up by British Intelligence which involved secret wireless monitoring. The information they fed to Bletchley Park provided much of the raw material required to break into enemy codes and cyphers.

In addition, radio amateurs, many of whom possessed considerable technical skills, played a key role in technological developments such as counter-measures against enemy air attacks, in the defeat of the magnetic mine, developing ultra-high frequencies and as instructors at the top-secret radio and radar schools.


Voluntary Interceptors

Radio amateurs were particularly adept at reading weak Morse transmissions, caused by interference from background noise or other nearby signals. They were recruited into nine regions with a Captain from the Royal Signals as Regional Controllers. VIs were given a reference number, some blank log sheets, postage stamps and envelopes addressed to “Box 25, Barnet, Herts”. VIs placed their completed logs inside a stamped addressed envelope which was then inserted into another addressed envelope to Box 25.

VIs were often given particular frequency bands to search for signals using a certain type of procedure, and sometimes were asked to listen out for particular call-signs and to take down any messages which appeared in coded groups of five letters – the standard method of sending secret information by Morse.

Frequencies most used were between 3 MHz and 12 MHz, with the concentration from 4 MHz to 9 MHz. Much of this band was occupied by broadcast stations and Morse used by the Services and the press. But with some 5-6 million cycles of band, in which a Morse signal only required a one-thousand cycle space, in theory there could be 3,000 stations – excluding that used by broadcasters – which could be operating simultaneously, hence the need for a nationwide team of VIs.

Wormwood Scrubs Meeting

At the beginning of the war a small department was set up by the Security Service (MI5) to detect enemy radio transmissions from agents believed to be operating within the UK. The RSS became part of MI5 and eventually Section C of MI8 before finally being taken over by MI6 as its Section VIII, the illicit wireless intercept group. A radio amateur, Lord Sandhurst, was appointed to develop the organisation. He contacted Arthur Watts, President of the Radio Society of Great Britain (RSGB), the governing body for radio amateurs. The interview took place in a cell at Wormwood Scrubs, as a number of cells had been taken over for what became the first headquarters of the RSS, with a direct teleprinter link to Bletchley Park.

Watts recommended harnessing the entire RSGB Council, and the RSS was in business, at first called the Illicit Wireless Intercept Organisation. To disguise their role, many VIs were dressed in Royal Observer Corps uniform.

The Secret Of Box 25

Initially, messages logged by VIs were sent to Wormwood Scrubs, but the volume became so great that the RSS was moved to Arkley View, a large country house in the village of Arkley, two miles north of Barnet. It was given the secret address of P.O. Box 25, Barnet, to which the VIs sent their Morse messages of enemy signals. These were then forward to Bletchley Park. The organisation later moved to Hanslope Park, just north of Bletchley Park. The site where Arkley View stood is now part of a housing estate.

Hanslope Park

The move from Arkley View to Hanslope Park began in August 1941 and the leading personnel were again amateur radio enthusiasts, with Wilfred Limb and William Chittleburgh arriving as wireless operators. Hanslope officially opened in May 1942 and its second Commanding Officer was amateur radio man Reginald Wigg. Hanslope was so important that it was visited by VIPs such as Field Marshal Montgomery and General Eisenhower. Post-war it was taken over by the Diplomatic Wireless Service.

Rss Role Expanded

When it became clear that there was no enemy spying activity within the UK the RSS was given the task of monitoring signals abroad, and particularly the messages of the German military intelligence organisation, the Abwehr. The largest Abwehr signals came from Group 2 – Berlin (the RSS codename for Berlin was Bertie).

Norwegian Triumph

In March 1940, the RSS intercepted wireless traffic between Hamburg and the German spy ship Theseus, which was carrying out observations inside Norwegian territorial waters. But the ship was left alone because of the cryptanalytical value of her transmissions. These messages were intercepted by the RSS after a tip-off from a double agent and decrypted at Bletchley Park. These were the first examples of intelligence from the ciphers of the Abwehr.

Invasion Of France Uncovered

In spring 1940, the RSS intercepted traffic that revealed the forthcoming blitzkrieg on 10 May 1940 against France, Belgium and Luxembourg. Indeed, it was the RSS itself which broke the ciphers, which led to reprimands all round, as codebreaking was Bletchley Park’s job. When decrypted, the traffic, which was originally restricted to Gestapo affairs, began to carry enquiries about defences, road blocks, troop dispositions and other military topics in the area where the Germans later made their attack.

Abwehr Cipher Broken

In June 1940, it was decided that, in order to release wireless operators who were desperately needed to intercept Luftwaffe Enigma traffic, the RSS would cease to intercept the Abwehr link, and the objections of RSS were overruled again, but RSS and Bletchley Park later obtained permission to resume the interception. When Bletchley Park finally broke the cipher used by the Abwehr’s main wireless network, it turned out to be the hand cipher used by the Abwehr and its agents abroad.

“Turned” Agents

Captured enemy agents were either executed or “turned” and made to send messages back to their German handlers as if they were still free. These were central to what became known as the Twenty Committee – Twenty in Roman numerals is XX – so the organisation became known as the Double Cross system. Again, amateur radio hams were involved, as many of the turned agents were handled by them. Part of their role was to ensure that Morse signals sent back to Germany contained the messages which had been dictated to them by MI5.

Direction Finding

Amateur radio personnel were also used in the important role of Direction Finding or “DF” by which a signal could be picked up from several locations, and where the signal crossed the beam of the various intercept stations listening in, was the spot from which the signal was coming. It was used with particular accuracy to track U-Boats, and also enabled, among other things, to reveal the site of key enemy wireless stations.

Unmasking Of Cicero The Spy

One RSS success story turned out to be so good they found themselves with a problem. The story was told by Hugh Trevor-Roper (later Lord Dacre), who worked with the RSS. In a BBC broadcast called The Secret Listeners in 1979, he explained that they knew all about Cicero, the German code name for the spy who was valet to the Ambassador at the British Embassy in Ankara, who was passing secrets to the enemy. It was later made into a film with James Mason playing the part of Cicero. Trevor-Roper said that they could not tell the Ambassador by telegram for these were being read by Cicero.

If the RSS had revealed what they knew about Cicero, the Germans would have discovered that we were reading their ciphers. So people had to be sent out personally to Ankara to brief the Ambassador. Sadly for Cicero, who fled to South America after the war, he was arrested there for passing counterfeit money – the Germans had paid him in forged currency!

Counter-Intelligence Value

Abwehr decrypts were most valuable for counter-intelligence purposes, and the RSS retained responsibility for decrypting them and became the chief adviser on the use to which they were put. From its scrutiny of such things as the questions the Abwehr was putting to its agents, and the adjustments it was making to its organisation, the RSS could sometimes extract intelligence of operational and political interest. The RSS developed a section to look after the interests of other customers than MI5 and MI6 and appointed watchkeepers to Bletchley Park.

Churchill Becomes Involved

Winston Churchill came into the RSS picture in 1940 when the capacity of the Services to intercept Luftwaffe Enigma traffic lagged behind Bletchley Park’s decrypting capacity because of a shortage of wireless operators. On Churchill’s instructions, Lord Hankey, secretary to the Committee for Imperial Defence, overruled protests from the RSS operators and transferred them from MI5 to MI6 in May 1941 under Brigadier Richard Gambier-Parry, another radio ham, to form the communications unit of Section VIII. Another radio amateur, Lt.-Col. Kenneth Morton Evans, later became his deputy.

Disagreements Between MI5 and MI6

In June 1941, MI5 complained that it was denied an equal voice in the control of the RSS and was forbidden to have direct contact with Bletchley Park, but these problems were later resolved, and the shared interest of MI5 and MI6 in the RSS produced little disagreement after the middle of 1942. The MI5/MI6 Wireless Committee had been set up in 1941. In December 1942 it was agreed that it should be replaced by two new committees, one to decide major questions affecting RSS policy and the other a committee at working level.
The former, the Radio Security Committee, was established in March 1943, responsible for co-ordinating the interest of MI5 and MI6 in the RSS and for supervising radio security. The overall organisation became known as the Radio Security Intelligence Conference. Within this framework the administrative and technical development of the RSS encountered few difficulties.

Thanks to John (2E0HJJ) for contributing this article.

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