Sophisticated decoys setup across Britain to divert German bombers during the Second World War are now all but forgotten, writes E&T.
When archaeologist Dr Bill Bevan set out to survey Burbage Moor in Derbyshire in 2005, he found more than just the signs of ancient settlement he was expecting. There was also evidence of more recent human activity - the remains of what turned out to be one of the decoys set up by the British government during the Second World War in an attempt to divert German bombers away from nearby Sheffield. Apart from disturbance of the land and sunken control rooms, little remained of these decoys and most had been entirely forgotten.
As some decoys covered a considerable area, their existence during the war was well known to the farmers on whose land they were often situated, and to others who lived or worked in the countryside. In keeping with the wartime code of secrecy, however, they talked little about them. Nevertheless, an article, 'Red Herrings for Luftwaffe', appeared in Flight magazine as early as November 1945. The author wrote of the decoy lighting, decoy fires and 'dummy production plants complete with parks of [derelict cars], dummy roads, real smoke from dummy chimneys, and all the other necessary trimmings including dummy aircraft on the alleged tarmac.'
Decoys had first been used during the First World War on the Western Front by the Royal Flying Corps, who constructed fake airfields consisting of tents, huts and a few unserviceable aircraft, 3km from real airfields and in the likely line of flight of bombers. At night paraffin flares were added.
On the home front, soon after the start of Zeppelin raids on Britain in 1916 it was quickly realised that advantage could be taken of the tendency of the aircraft's crew, on arriving at the coast, to head for the first set of lights they saw and drop their bombs.
The effect of bombs on the civilian population was of great concern for the British government as a Second World War seemed inevitable. Extrapolating from the statistics of the First World War, there was a great fear that German aircraft might drop 35,000 tonnes of bombs on the first day alone, severely traumatising the cities' inhabitants and possibly even inducing surrender. Public morale cannot have been helped by the publication in April 1939 of Nevil Shute's 'What Happened to the Corbetts', a novel depicting a family driven out of a wrecked city by lack of water and fear of disease.
Decoys were not prepared ahead of time, even though in 1937 Air Ministry officials had been alerted to the possibilities of deception by a visit to filmmaker Alexander Korda's Denham Studios. It was only on 22 September 1939 that a department was formed, under former Royal Engineer, Colonel John Turner, who became known as the 'Dictator of Dummies'.
What eventually emerged was a plan to divert bombers from airfields and some factories during day and night, and from cities at night. Fake airfields were built a few miles from the genuine one, with ten dummy aircraft, worn tracks, disturbed areas made to look like bomb and petrol dumps, an air sock and machine gun post. These were manned by up to 20 people, part of whose job was to move the dummy aircraft to imitate activity.
When dummies produced by aircraft manufacturers proved too expensive, Colonel Turner turned in part to Norman Loudon's Sound City film studios, starting a relationship that continued throughout the war. They were, as Colin Dobinson writes in his book 'Fields of Deception', 'adept at contriving visual illusions cheaply and at great speed'.
At night the whole lighting of an airfield was reconstructed using: a T-shaped wind direction of yellow lights and four alternatives, with the ability to switch between them; four red lamps indicating high buildings and other obstructions; and a car headlamp that was moved to indicate a taxiing aircraft, which, when swung into line, could be seen by an approaching aircraft five miles away. To prevent friendly aircraft landing - which was a genuine danger - the lights would be doused, dimmed or subtly changed.
In contrast to the daytime decoy, this could be operated by only two people. Colin Dobinson quotes from a circular sent out by Colonel Turner. When contacted by telephone about an imminent raid 'The man on watch wakes his companion and starts up the generator' One man goes to the control panel and switches on the correct T, the obstruction lights and the headlamp. The two men take it in turns to manipulate the headlamp until the aircraft is close enough to pick up the landing T.'
For four aircraft factories, including Short Brothers at Rochester, full-size replicas were built by the Sound City Studio engineers, but it was obviously beyond even them to set up a complete dummy town. It was possible however to replicate the lighting of a town during the night. After reconnaissance flights had shown exactly what needed to be done, the studio started imitating leaky blackouts from skylights or open doors, the overhead lighting in railway marshalling yards, train engine fires, electric tram flashes and the glow of a coking furnace.
However, this decoy lighting was little help once the bombing had started and fires or incendiaries had been dropped on the real target. As the author of the Flight magazine article wrote: 'the answer was pretty obvious. The enemy used fires as target marker; then we'd provide them for him - but outside the borough boundary.' The aim would be to let the first wave of bombing through and hope that subsequent waves would drop their bombs on fires ignited several miles from the city.
With the near total destruction of Coventry city centre on 14 November 1940, it became clear that vulnerable cities needed immediate protection. From rapid improvisation on 23 November - which largely consisted of igniting oil poured into hastily dug pits outside Birmingham and Coventry - a network was built up so that by April 1941, 42 towns were protected, each having several fire decoys, some overlaid on lighting decoys. A variety of fires were arranged in groups to simulate a burning town.
Trevor Denniff, who was sent to a fire decoy outside London in 1940, described his arrival in a talk in 1998. 'When I was trucked onto Farleigh Common starfish site for the first time that late December morning, the film crews were already busy erecting a series of skeletal structures all over a valley farm, covering an area of about one mile by a quarter with scaffolding towers and blocks of wire baskets. Pairs of 1,000-gallon galvanised tanks were positioned on top of six-metre-high towers, one filled with water and the other with diesel or paraffin.'
Replenishing the tanks and clearing charred debris was not a pleasing job, Denniff recalled. 'We only operated about half a dozen times, which is quite as well as it was a very filthy business. Our landlady showed amazing tolerance.'
The success of these attempts to divert air attacks was variable with the night decoys attracting more bombs than the daytime dummy airfields. Attacks on Liverpool were not prevented, while Leeds was seldom bombed. Colin Dobinson has worked out that 5 per cent of bombs were deflected, sparing perhaps 3,160 injured and 2,596 dead. Of course few in the towns would have known of these attempts to protect them but it must have made it easier for those in government to sleep at night, knowing that they were doing all they could to save the towns and cities.