The Special Operations Executive (SOE) in Hertfordshire

Caroline Churton

Fans of the James Bond films will be familiar with the range of often seemingly improbable gadgets and gizmos that ‘Q’ comes up with, all intended to help 007 when he gets into sticky situations with his various adversaries. But while these may seem rather implausible and simply the creations of an imaginative author or script-writer, in many instances they are actually not that far removed from fact. They were inspired by real inventions that were devised by members of the Special Operations Executive (SOE) during the Second World War.

This secretive organization, which was backed by Winston Churchill, was established on 22 July 1940, shortly after the start of the Battle of Britain and after France had fallen to the Germans, with the main aim of engaging in espionage and sabotage against the enemy by various subversive and unorthodox means – in Churchill’s words ‘to set Europe ablaze’. The training for agents – both men and women – was gruelling, the work in enemy-held territory was extremely dangerous and, if they were discovered, agents were at risk of torture or execution. They were generally parachuted into occupied Europe, or the Far East, where they would work with and support local resistance groups, blowing up trains, bridges, factories and other infrastructure, and generally causing as much destruction and disruption to the enemy as possible. One of its bravest and most famous spies, Wing Commander Forest ‘Tommy’ Yeo-Thomas, who was known by the code name White Rabbit, is now believed to be the inspiration for James Bond himself ….

SOE Stations

The administrative headquarters of the SOE were based in and around Baker Street in central London, but to meet the needs of those involved in experimental work, research & development, and training, the Government requisitioned numerous large properties in various parts of Britain. These were identified by numbers – training schools were given Arabic numerals, such as STS 43 (Audley End House in Essex), and experimental establishments were given Roman numerals, such as Station XIV (Briggens in Essex). In total there were about 56 training schools and 17 experimental establishments. Just two of the training schools were in Hertfordshire, but there were eight experimental establishments based in the county. These were:

  • Station VI Bride Hall, near Ayot St Lawrence – weapons acquisition section
  • Station VIIb Yeast-Vite factory, Whippendell Road, Watford – wireless section: packing and dispatch
  • Station VIIc Allensor’s joinery factory, King George’s Avenue, Watford – wireless section: research
  • Station IX The Frythe estate, near Welwyn Garden City – initially a wireless research unit (Special Signals), then a weapons development & production centre, then a research & development station
  • Station XI Old Gorhambury House, near St Albans – accommodation
  • Station XII Aston House, near Stevenage – production, packaging and dispatch
  • Station XV The Thatched Barn, Borehamwood – camouflage section
  • Station XVII Brickendonbury Manor, Brickendon, Hertford – explosive trials

All of these Stations played vital roles within the SOE, but there were four – Bride Hall, The Frythe, Aston House and The Thatched Barn – that were regarded as some of the most important establishments in the organization.

Station VI: Bride Hall

Bride Hall, near Ayot St Lawrence, c.1834 (credit: Hertfordshire Archives & Local Studies)

Bride Hall, near Ayot St Lawrence, housed the Weapons Acquisition Section, which was located in a number of spacious barns. Station VI’s main task was to gather weapons by any means possible. Several public appeals were launched in 1942, 1943 and early 1945, asking the civilian population to donate any serviceable weapons to the cause – this resulted in more than 10,000 small arms being acquired for use by the SOE and resistance groups in Europe. In total the Station sent more than 100,000 guns of various kinds for use in the field.

There was also a Small Arms Section at Bride Hall, which was responsible for repairing, servicing and testing weapons. A 30-yard (27.4 m) range was constructed in the grounds to facilitate the testing.

Station IX: The Frythe

The large mansion known as The Frythe, near Welwyn Garden City, was for the most part a research & development Station. Major John Dolphin, himself a scientist, was appointed to command the work that was carried out there. Station IX specialized in developing a whole range of 007-like inventions, many of which were designed by the highly regarded Major Hugh Reeves. Most were named using the first three letters of the Station’s location – i.e., Wel – and included both weapons and specialized forms of transport suitable for agents operating behind enemy lines.

One such weapon was the Sleeve Gun, a device that quite often appeared subsequently in films. This was a silenced tube with a .32 calibre round in it that could be hidden up an agent’s sleeve. When needed it was slid into the agent’s grip and activated by a button near the end of the barrel, before being quickly concealed again once it had been fired. Another silenced pistol, the Welrod, fired either .32 or 9 mm rounds. This assassination weapon had a combined magazine and grip, which could be removed for ease of hiding – as a result the remaining innocuous-looking barrel was sometimes referred to as a ‘bicycle pump’ because its real purpose was disguised. Major Reeves also designed a silencer for the widely used Sten submachine gun.

The Frythe, near Welwyn Garden City (credit: Hertfordshire Archives & Local Studies)

The Welbike was an ingenious piece of kit that was designed to fit inside a parachute canister. It was a very small, single-seat, folding motorcycle, weighing only 71 pounds (32.2 kg), which could travel at up to 30 miles (48.3 km) per hour, with an amazing range of 90 miles (144.8 km). 3,641 Welbikes were produced and they were used in several major wartime operations throughout the Second World War, as well as by SOE agents.

Other inventions included a basic and cost-effective submarine gun called the Welgun, and the intriguingly named Welbum. The latter was a small metal container with an electric motor and battery inside. The device could be strapped to the back of a parachutist who was to be dropped into water, and by means of a screw it would provide enough power for the swimmer to travel silently for 2 miles (3.2 km) at a speed of 2 knots (2.3 mph). The very successful and widely used Time Pencil was also developed here. This was a compact time fuse that would be connected to a detonator, allowing saboteurs planting explosives enough time to escape to safety. The delay could be anything between 10 minutes and 24 hours, depending on the type of fuse that was used.

One of the items most associated with agents working undercover in enemy territory in Europe is the suitcase radio. It was essential that agents were able to communicate with their contacts in Britain, sending messages in Morse code at a designated time each day, and various portable radios were designed and developed by the SOE at Station IX. One of the most practical, being both light and robust, was the Type B MkII, known as the B2. This fitted into a small suitcase and had a transmitter, receiver, mains power supply and a built-in battery as a back-up. The battery could be charged with a small dynamo that could be powered either by cranking by hand or by attaching it to a stationary bicycle and turning the pedals to produce a current. An even smaller and lighter version, the Type A MkIII, with a range of up to 500 miles (804.7 km), was subsequently developed.

Not all of Station IX’s ingenious inventions were so successful however. A one-man midget submarine, the Welman, which was developed in 1941, was used on only one mission as it was thought to be too risky. It was about 20 feet (6.1 m) long and was loaded with a 425-pound (192.8 kg) high explosive charge that could be attached to an enemy warship. In 1942 another small submersible was produced, the Welfreighter, which looked like a boat. It too was loaded with a high explosive charge, as well as mines, but by the time it was ready for action the war was nearly over and it was never used. Similarly, a 12-foot (3.7 m) Motorized Submersible Canoe, which was called ‘Sleeping Beauty’ and was intended to be used by a frogman to carry out reconnaissance or sabotage, also never actually saw action – collapsible canoes tended to be used for such purposes instead.

Station XII: Aston House

Aston House, near Stevenage, specialized in the production of many of the weapons and explosive devices used by the SOE, often referred to by those in the know as ‘toys’. It worked closely with The Frythe, with the two establishments involved in both research and production, sometimes collaborating on the same inventions. All the equipment produced for SOE agents needed to be light in weight for ease of transport, strong enough to survive parachute drops, and ideally disguised so that it could be carried in public without arousing suspicion.

Aston House was the first establishment to experiment with plastic explosive for sabotaging German installations and railways. It also made a range of explosive charges and fuses, including 12 million of the time pencil fuses developed at Station IX, and created a gas-ejecting pen (very James Bond!) and an exploding bicycle pump.

Station XV: The Thatched Barn

The Camouflage Section was based at The Thatched Barn, another large property that was formerly a hotel, in Borehamwood. Its main role was to equip agents prior to their deployment to France. The Station was run by a film director, Captain J. Eldar Wills, and his team included stage-prop experts from the film industry. They had the skills to produce French-styled items of clothing that were accurate down to the last stitch, button and label. A special camouflaged parachute jumpsuit was also produced. This was designed with large pockets to hold a pistol, a knife to cut parachute lines, and a shovel with which to bury the parachute on landing. Maps were sewn into silk underwear and compasses would be concealed in matchboxes. And to ensure that agents looked the part when operating in Germany, hairdressers would be brought in to give them German-style haircuts. Station XV was also responsible for ‘ageing’ the suitcases that contained the radios used by agents in the field.

The Thatched Barn was also involved in the development of booby traps. These included items such as bicycle pumps which were turned into bombs, grenades hidden in tins that supposedly contained fruit, exploding cigarettes, a smoking pipe with a detachable mouthpiece and a steel dagger concealed in the stem, and a pencil with a thin blade inside instead of lead, to name but a few. Because plastic explosive could be easily moulded into different shapes this was often used to create all sorts of imaginative explosive devices. Examples of these were explosives disguised as dead rats or lumps of coal, which could be left in coal piles and when thrown into the firebox of a locomotive would explode and destroy both the train and the track. In a similar way land mines could be disguised as cow dung or other animal droppings.

SOE Training Schools

The two training schools based in Hertfordshire were STS 17 Brickendonbury Manor (sabotage) and STS 19 Gardener’s End, Ardeley, Stevenage (bonzos – anti-Nazi Germans – for Operation Periwig).

STS 17/Station XVII: Brickendonbury

Brickendonbury Manor, near Hertford, had two roles – as Station XVII it specialized in explosives and industrial sabotage techniques, but it was also known as STS 17, the first SOE training school. In this capacity it was used as a major training centre for resistance fighters who came over from occupied Europe to learn sabotage skills before being parachuted back to their home countries. Here they would learn how to blow up everything from trains to bridges. Part of the Brickendonbury grounds was set aside as a demolition research area.

Brickendonbury Manor, near Hertford (credit: Hertfordshire Archives & Local Studies)

The training for potential SOE operatives was rigorous. After an initial period of assessment, successful candidates would undergo intensive paramilitary training, which covered demolitions, weapons, tactics, intelligence methods, communications and parachute training. After this they would move on to Finishing School, where they were trained in secret-service methods, propaganda, the organization of enemy forces, and the local conditions in the relevant occupied country.

Thanks, no doubt, to this training, one of the SOE’s most successful acts of sabotage was the destruction of the Norsk Hydroelectric (‘heavy water’) Plant at Rjukan in the Telemark region of Norway in 1943, an achievement later featured in the 1965 film The Heroes of Telemark. The resistance fighters had been able to practise their daring raid using a mock-up of the hydro plant that had been built in the grounds of Station XVII. Many other important sabotage and espionage operations were also planned there.

In its role as Station XVII Brickendonbury carried out explosive trials. The limpet mine, so named because it resembled the shape of a sea snail, was first developed here by inventor Stuart Macrae. This explosive device could be attached to the hull of a ship by strong magnets and was successfully used by the SOE during the Second World War. They also made an appearance in several James Bond films, including Live and Let Die, The Spy Who Loved Me and From Russia with Love!

STS 19: Gardener’s End, Ardeley, Stevenage

Members of the SOE based at Gardener’s End were involved in a secret operation known as Operation Periwig. Its aim was to confuse and disrupt the Nazi regime by pretending that there was an active resistance movement within German territory. Setting up an actual resistance movement was perceived by the British authorities as almost impossible, but by inventing a fake movement it was hoped that the Nazis would waste valuable time and resources in trying to track down the alleged resistance fighters, who of course did not in fact exist.

As part of the plan anti-Nazi prisoners-of-war who had been brought to Britain, known as ‘bonzos’, were specially trained for the purpose, although they did not know the real reason behind their training. They would then be parachuted into Germany, thinking their mission was to join resistance fighters and commit acts of sabotage. The hope was that they would be captured by the Gestapo and when interrogated would reveal what was in fact inaccurate and worthless information about their supposed activities. To suggest further the existence of resistance groups, fake wireless messages and equipment such as fake code books would be deliberately allowed to be discovered by the Germans.


By D-Day on 6 June 1944 the SOE had become a major organization, much feared by the enemy as its operatives could strike anytime anywhere. Its agent networks extended right across occupied Europe and the Far East, and while no exact figure is known as to how many men and women were involved in the SOE, it is estimated that it had at least 10,000 personnel, of which half were agents. The combination of skilled, inventive scientists, designers and technical engineers, and the incredibly brave men and women of this secretive organization, who risked their lives daily as agents in enemy territory, without doubt played a major role in Britain’s ultimate success in the Second World War. They did indeed ‘set Europe ablaze’.


This page was added on 22/03/2023.

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  • Gorhambury (Station XI) is mentioned in Ben Macintyre’s “A Spy among Friends” as Kim Philby was stationed there. There were convivial weekends at the King Harry public house. The locals understood them to be archaeologists studying Verulanium.

    By J Ayto (01/06/2023)