SOE
Page 29
In Jacqueline, Pioneer Heroine of the Resistance, reference is made to a necklace which could be strung with large and small beads in an order that would transmit, when stroked, a pre-selected message at 600 words a minute. Reception was said to be by an American wire recording machine. The author of this book sought to obtain further details from her sources in France but, alas, they had all died.4
There is some evidence that a German wireless link existed between Sweden and Norway which used high-speed morse tape transmitters. These had been built on German orders in Danish factories which had been commandeered. With the help of Danish engineers units were obtained and passed to Royal Signals officers working with SOE.5 The Danes were said to have a ‘natural aptitude’ for wireless telegraphy matters which might have accounted for the report of a ‘squirt’ test from Stockholm in June 1944.6
Further evidence of the Danes’ expertise in this field is quoted by M.R.D. Foot in Resistance (p. 276). One of SOE’s leading organisers in that country was the Chief Engineer of Bang & Olufsen, Lorens Arne Duus Hansen, whose position gave him access to worldwide technical information as well as many contacts throughout Europe. In the spring of 1943 he completed the third version of a transceiver the size of a Copenhagen telephone directory; much more compact, more powerful and lighter than the British sets in use. Moreover, it used many domestic radio parts so spares were much less of a problem. In August Hansen persuaded SOE to let him supply radio equipment to the Danish Resistance and eventually built around sixty ‘telephone book’ sets.
At some point, the date is not clear, London asked Hansen if it was possible to transmit morse at high speed. He constructed an electrically driven device in which a paper strip which had been perforated with holes corresponding to the morse message was ‘read’ by an automatic key and transmitted at seven times the best conventional rate. The signals were recorded in England on wax discs and then played back at a slower, readable speed. The system was used in a limited way in Copenhagen and Jutland. The Gestapo is said to have ignored the rapid transmissions for some weeks on the basis that they hadn’t such equipment of their own and it must be too sophisticated for the Danish Resistance.
Another ingenious invention of Hansen’s was a means of remote-controlled transmission via the telephone system. Although this was very safe for the operator, it was impossible to change crystals if reception proved poor and it was used to only a very limited extent.7
Further evidence that SOE was actively considering ‘squirt’ transmissions lies in the fact that in the summer of 1944 Station 53b reported that ‘Silk Blue has commenced high-speed transmission in the neighbourhood of 100 words per minute and we have successfully received three transmissions covering some thirty messages by this means.’8
Meanwhile, Jones was continuing work to improve the ‘S’-phone. Air-to-ground trials took place on Newmarket Heath and a simulated reception committee under Bovill would gather in the pitch black of a field near Luton to home-in the aircraft and receive a stick of containers from a Halifax based at Hatfield aerodrome. Less hazardous trials took place at Fishguard using a French fishing boat which had been modified for SOE use. Considerable difficulties were being experienced at this time with the development of the Homing ‘S’-phone. In June 1943 Wng Cdr J.C. Corby had been led to believe it was almost ready and was anxious to make use of it. He wrote a letter of complaint to Col Davies and was no doubt advised to be a little more patient.
In 1943 planning was in hand for the invasion of Europe and for offensive action in the Far East. Soon Jedburgh teams of three men were being trained for infiltration into German-occupied territories to organise and prepare Resistance groups for action after the Allies landed on D-Day. It was essential that they had good wireless communications. Various modifications to the Type B Mk II were carried out at their behest. A steam-driven battery charger was also constructed. The tropicalisation of the set needed improving to reduce the ingress of dampness and subsequent rapid mould growth on components, and so Brown designed and built test cabins to simulate Far Eastern conditions in the laboratory.
In the second half of 1943 demand on all departments at Station IX was increasing as the prospect of the ‘Second Front’, i.e. the invasion of Europe, came closer. Recognition of the importance of signals was its elevation to a Directorate under Brig F.W. Nicholls, who also became a member of SOE Council in September. He was thus responsible for the whole signals organisation including research and supply. Alongside the very real problem of securing suitably qualified and skilled staff to meet these needs, there was also the question of accommodation. What, if any, attention was paid to planning the layout of the hastily erected huts and hangars at The Frythe is not known. The general disposition appears to have been to the south and south-east of the mansion, perhaps to take advantage of the screening afforded by the trees and rhododendrons, perhaps to avoid encroachment on traditional facilities such as the kitchen garden and the Head Gardener’s cottage. Whatever it was, the decision seems to have been taken that further expansion of the work of Station IX had to be catered for elsewhere.
The Radio Communications Division had already moved its Headquarters, Production Unit and Supplies Section to Wembley in June of the previous year, leaving only the Laboratory at Welwyn. Then expansion of Supplies Section called for a further move of this group which now numbered 70. In February 1943, under Maj E.J. Kennedy, it transferred to more commodious premises, complete with packaging and despatching facilities, at the Yeast-Vite factory (Station VIIb) at the northern corner of King George’s Avenue and Whippendell Road in Watford. RCD as a whole had expanded from 60 to 320 persons in one year and now all that was left of them at their original home were the 50 in the Laboratory.
Whether the dispersal of the sections was a deliberate policy to avoid keeping all its radio eggs in one basket or was forced upon SOE by sheer lack of suitable accommodation in one place, we shall probably never know. Communication and liaison between the sections must have been difficult for they were now many miles apart. Further dispersal occurred when the Microwave Section of the Production Unit outgrew its premises and found a new home a short distance away in Park Royal. Here it installed Bakelite moulding presses, the press tools for them being made in the factory.
Autumn 1943 saw the last of the original wartime occupiers of The Frythe leave in mid-October when the RCD Laboratory moved to Allensor’s Joinery Works (Station VIIc) in King George’s Avenue, Watford, just a stone’s throw from the Supplies Section. Shortly after this move Maj W. Glendinning succeeded Mr G.W. Willis as head of the Laboratory.
The maintenance of wireless communications with covert agents had always been dogged by the problem of providing a reliable power supply for the sets. One could not guarantee to operate in an area with a notional electrical mains supply, let alone a reliable one. The batteries of the day on the other hand, were fragile in delivery by parachute, needed maintenance with acid and were bulky and heavy to carry around. SOE’s experts therefore addressed the problem by designing a series of battery chargers and generators powered by various means from human hand to fire (see later section). Brown’s next project was to be one which incorporated a pedal-powered generator in lieu of batteries.
The Type B Mark III Transceiver
At the end of 1943 Brown was asked to produce the Type B Mk III and work started seriously in 1944. This was to work on both CW (morse) and R/T (radio telephone), be positively buoyant, man-carried, capable of operating for several months at a time in the jungle, be fully tropicalised, have die-cast aluminium cases and be hermetically sealed. It would be delivered with a pedal generator in place of troublesome batteries. The whole of 1944 was spent on this project. The pedal generator gearbox was produced by Rotol Ltd, the airscrew company, Hoover made the special generator and Marconi and Radio Gramophone Developments (RGD) were given contracts for the wireless sets. The first models were produced in early 1945 but not more than 500 were completed before the end of the war when the
Type B Mk III was handed over to Marconi. The very demanding specification for the Far East requirements had come from Col J.A.C. Knot. In retrospect, all these requirements might not have been necessary and a lower specification could have resulted in it being in service at an earlier date.
So now the Radio Communications Division was dispersed with the Production Unit (Station VIIa) at Wembley and the Supplies Section (Station VIIb) and Laboratory (Station VIIc) at Watford. Dormitory and messing facilities for many civilian and service personnel from The Frythe were provided at Gorhambury House near St Albans which was designated Station XI and was under the command of Maj H.F. Riach. These facilities applied no less to the now scattered RCD. Maj Brown was sharing accommodation with Capt Mats Jenson of the Norwegian Army when they discovered that in the cellars beneath was a clandestine radio station named ‘Buttercup’ used for transmitting black propaganda to Germany. ORs housed at Gorhambury House were billeted in converted stables which were destroyed by fire on 29 January 1944. Thereafter a small camp of six Nissen huts was provided close to the stables. These were fully occupied by men from Stations VIIb and VIIc below the rank of sergeant. Civilians, sergeants and higher ranks were billeted in the house itself, where there were also some female secretaries from Station IX. But the majority of staff from Stations VIIb and VIIc were housed in civilian billets, where the householder had the advantage of a little more money and another ration book to manipulate. SOE’s base stations at Grendon (Station 53), between Aylesbury and Bicester, and later at nearby Poundon (Station 53b) consisted of 125 acres of aerials and many FANYs listening round the clock. As traffic built up it was realised that SOE didn’t have enough channels to cope with it. The Post Office Research Establishment at Dollis Hill in north west London came up with the wideband amplifier which was highly directional and could receive up to forty low-powered transmissions. Brown was asked to design small drive units for the wide band amplifiers.
The 51/1 Transmitter
Towards the end of the war SOE produced the 51/1 transmitter measuring 4½ in × 1½ in × 5¾ in, small enough to be carried in an agent’s pocket. It weighed only 1¼ lb (567 gm) complete with its battery. It could also be powered by 110–240 volt mains supplies and had a coverage of 3–10.5 megacycles on two wavebands. The power output was 4 watts which enabled the set to send astonishingly clear messages over distances up to 600 miles.
Brown was given the assistance of Dr Yates-Fish, who worked on aerials, and Flt Lt Jack Stowery, on a rest from the field. They soon learned that signals being received were so strong that less powerful, and therefore even smaller, sets could be used. Brown drafted the design for a truly pocket-sized set and Yates-Fish and Stowery finished it as Types 50/11 and 50/31 designs. A small number were made but in the spring of 1945 it was too late in the war to enter serious production. Some of the special components which Brown had incorporated into his sets appeared in postwar designs by the Government Communications Research Establishment (GCRE) at Elstree, and the Diplomatic Service and SAS used his wireless sets as late as the Sixties. His vital work over, Brown was posted back to the Royal Signals at Catterick and subsequently given a draft to Italy.
Miniaturisation of wireless equipment was not restricted to the Allies. The German wireless detector vans with their roof-mounted rotatable aerials were easily recognised by Resistance lookouts, who could pass on the appropriate warnings. The vans were later replaced by converted saloon cars, in France frequently the ubiquitous black Citroën. The equipment was subsequently developed to the stage where the German searcher had it hidden beneath his clothing with an indicator strapped to his wrist. Wireless operators and their guards subsequently kept a lookout for fat men who constantly looked at their wrist watches!
There was no doubt that SOE pulled together a great deal of technical talent, a match perhaps for the bravery of those in the Country Sections. Recruiting was done largely on the ‘old boys’ network’, one eminent officer, scientist or engineer being asked if he knew of anyone suitable for such and such a job. As with other Sections, RCD’s recruitment procedure meant that anyone recommended in this way was often too deeply involved before they realised exactly what organisation they had entered. John Brown of the Wireless Section had never heard of SOE until 1944, three years after he started work for them! Security was very good. Newcomers were told that whatever they needed to know to do their jobs, they would be told. Any questions were to be addressed to their immediate boss. Hence, if anyone had been noticed to be asking questions of others, they would come under suspicion – but there were few, if any. John Brown was particularly careful what he said when he attended meetings in London, a task for which he was allocated a motorcycle as his personal transport.
For the lower ranks, when there was a lull in the general tempo of activity they could be put on other duties such as firing off silenced Sten guns on the range to test for wear on the components. Eric Slater was once sent to Baker Street to install a hidden microphone in a room to be used for the interrogation of a North African woman agent suspected of betrayal. He did not, of course, ever know the outcome.
BATTERY CHARGERS AND GENERATORS
As briefly mentioned earlier, the scientists and engineers also considered the peripheral needs of the agents by designing radio battery chargers driven by hand, pedal, petrol, mains power and steam. The latter was devised at Station VIIc, based on a small steam engine with a drum boiler, and is reputed to have worked well. There was even a thermal-powered charger, based on an American design, which consisted of a 9 in diameter metal chimney standing 18 in high on three feet. Around the chimney were hundreds of thermo-couples which, when a fire was lit within the chimney, were supposed to generate electricity. As far as the Norwegian section, for example, was concerned the steam generator was most popular despite its weight of 80 lb and the problem of the dispersal of its smoke. The petrol version was good where this fuel could be obtained, but it was very noisy and therefore dangerous to operate under clandestine conditions.
There were at least three pedal-powered generators, some of which were developed in the Model Shop at Station VIIc. One was a simple device which was clamped on to the rear forks of a standard bicycle. The chain was lengthened to run over the additional sprocket on the generator. When in use the bicycle was supported on its rear stand and the operator would pedal as required. Another version consisted of a foldable triangulated tube support with a bicycle saddle on the top, a set of pedals near the bottom and a chain driving the generator which was beneath the saddle. Without any handlebars or other means of steadying oneself while pedalling, this would have quickly become a tiresome and awkward exercise. A more sophisticated model, the type 52/1, was a development of a model captured from Italian Forces. This had a metal tube frame supporting a canvas seat from which extended a tube carrying a set of pedals incorporated in a generator. Although the operator’s semi-supine position looked quite comfortable, he still had to expend considerable energy in pedalling to drive the generator. A hand-powered generator produced for the Jedburgh parties took the form of a box with a cranking handle on one end, supported on three legs. Both the hand- and the pedal-operated generators were unpopular, being very laborious to use for any length of time, while the mains trickle chargers were useful as long as there was a mains supply available. The preferred accumulators were 6 volt, 80 amp/hr car types which had the drawback of being heavy and prone, not surprisingly, to damage when included in a parachute supply drop.
It is interesting to see the estimates of wireless sets required for the year 1945 and their costs. (To find the equivalent cost in 2001 multiply by 23.) SOE had found it necessary to provide each agent as far as possible with three wireless sets hidden in a local circuit and used in turn to avoid detection by the increasingly diligent German detection teams. To allow for other mishaps, SOE had to budget for nine sets to keep each operator in contact with London.