Night-Time Fire-Based Decoys
The "QF" site took a turn away from the lighting displays. Here was the first venture into fire-based decoys. Realising that a fire in the target area often drew more bombers onto it, in the summer of 1940 a number of aircraft factories, RAF maintenance units and ordnance works were provided with their own "shadow". Located three to four miles away, the idea was to light the fires of the dummy immediately an attack started on the parent site. This could turn into something of a race to put out the fires at the real site and light them at the decoy before the second wave of bombers arrived.
An interesting side development of the "QF" was the "Oil QF", an attempt to guard the country’s valuable oil reserves. However, the simulation of burning oil storage tanks proved to be surprisingly difficult. Where years of research had gone into avoiding oil fires, none, needless to say, had gone into making them. Moreover, the cost of maintaining the effects throughout a bombing raid was alarmingly high. With a consumption of up to 2,500 gallons of oil per hour needed to keep the fires going realistically, it was proving to be an expensive decoy. However, the problems were eventually overcome and the effect from the air of blazing "crescents", "rings" and "pools" of oil was very realistic. But, despite this, the "Oil QF" programme was adjudged to have been a "calamity" by none other than Turner himself. From the outset, the oil companies had been opposed to the idea of decoys, suspecting that they were likely to bring German bombers to the area of the parent site rather than keep them away. As the oil companies were responsible for manning their own decoys their non-co-operation meant that even after they became technically operational there was no-one to man the sites. In Essex, Shell Haven and Thames Haven stood empty for want of twelve men.
In the autumn of 1940, the mass bombing of Britain’s cities - and in particular the devastation wrought on Coventry - turned the attention of Colonel Turner’s department to the possibility of providing decoys to divert the bombers away from large urban targets. Clearly, nothing on the scale of lights or the small "QF" fires could possibly be convincing enough. What was needed was the replication, as far as was possible, of a city under incendiary attack. It needed fires on a truly legendary scale. And thus was born the fabled Starfish site, the largest, most sophisticated decoy built in the war.
Within days of the raid on Coventry on the night of 14/15 November, work started on the construction of these massive fire-based decoys around Britain’s major towns and cities. From Southampton to Glasgow, from Birmingham to Crewe, tons of wood, and indeed anything combustible, was gathered to make improvised bonfires to try and draw some of the bombers away from the centres of population. But although immediately successful in some places, notably Bristol, Derby and Sheffield, these makeshift fire arrangements needed to be improved to guarantee a long-lasting effect with different kinds of fire to give a realistic variety of colour and intensity. If the German bomber pilots were to be deceived into thinking they were attacking a blazing town, the effects needed to be dramatic, varied and sustainable.
Tests and experiments followed. Using steel tanks, troughs, pipes and grids, fuel could be made to pour, spray or trickle at timed intervals. Different kinds of inflammable materials, variously soaked with boiling oil, paraffin or creosote, could create the random fire effects of burning houses, factories and power stations. Finally, four kinds of fire source which could be "manufactured" were decided upon, and construction work, with the ever-energetic Sound City Films once again to the fore, began.
The Boiler Fire periodically released oil from a storage tank into a steel tray. This was heated by a 10 cwt coal fire which boiled the oil to such a tremendous temperature that it vaporised. When, every now and again, a gush of water was dropped into the tray, the effect was instantaneous and violent with huge flashes of white hot flame leaping up to 40 feet into the air. Storage tanks containing 480 gallons of oil and 200 gallons of water, could keep this dazzling display going for four hours. Some measure of the size of a Starfish site can be gained from the fact that a typical site could contain 12 - 14 Boiler Fires!
The Grid Fire used paraffin as its base. This was continuously sprinkled onto a hot metal grid to which was attached wire waste and metal turnings. This burned with a steady yellow flame and although not as startling as the Boiler Fire it introduced the essential ingredient of variety.
Basket Fires were the mainstay of Starfish sites. They came as a 21/2 cwt package of inflammable materials, boxed into a wooden crate measuring 3’ x 2’ x 2’. Soaked with creosote, these blocks were arranged in irregular groups of up to 24, sometimes even more.
Coal fires were exactly what their name implies, but on a grand scale. A double brazier, twenty feet long, held 4 cwt of creosoted firewood and three tons of lump coal, giving off a deep red glow. A variation of this fed diesel oil onto the burning coals through a sprinkler pipe.
A normal Starfish site could get through 25 tons of fuel in four hours. A few had double this capacity. In common with the lighting decoys and the "QF" sites, the Starfish displays were ignited electrically from a control bunker about 600 yards away. This was heavily built of concrete banked around with earth. Nevertheless, with bombs dropping so close, no doubt the decoy controllers kept their fingers crossed for the bomb-aiming skills of the German airmen!
By January 1943, over 200 Starfish sites had been built. From the first attack on a Starfish in December 1940, when 59 high explosive bombs were dropped on Stockwood, the decoy for Bristol, the sites were a great success. The most dramatic confirmation of this was on the night of 17/18 April 1941, when the decoy for Portsmouth, Sinah Common, drew more than 200 bombs and parachute mines intended for the city.
By June 1944, decoy sites had been attacked on 730 occasions. Each of these ranged from a single night-time bomber dropping its load onto a "Q" site to the mass attacks on Starfish sites. In drawing the high explosives and incendiaries on to themselves, they were undoubtedly responsible for saving the lives of thousands of people.
The Essex Picture
With an invasion expected on the shores of Southern Britain in 1940, it was natural that more defences were built in the south than in other parts of the country. This is not the case with decoys. The distribution of Starfish sites largely explains this, as, being intended for the protection of centres of heavy population and industry, they were mainly sited in the Midlands and North. Interestingly, the sheer size of London meant that it was seen as being almost undefendable as far as decoys were concerned. No enemy pilot was likely to be lured away from such a large target. One of the few that were set up for its protection was built at Lambourne End, near Chigwell.
The RAF fighter station at North Weald was covered by a dummy airfield at Nazeing. This was both a daytime ‘K’ site and a night-time ‘Q’. The question of how friendly aircraft could recognise a decoy for what it was had always been a problem. Nazeing, fully equipped with plywood and canvas Hurricanes, must have been particularly realistic, as a Wellington bomber, taking it for a genuine operational airfield, chose to make a landing there. Once down, even without the undoubted damage to it, it could never have taken off again and eventually it had to be dismantled and carried away by lorry.
A ‘Q’ site at Blackmore became the decoy for the USAAF base at Chipping Ongar. It was manned by American airmen and, as a sixteen-year-old in 1943, the local farm lad would often be guided homeward by the light on top of the control bunker. On more than one occasion the obliging Americans fired up the generator so that the ‘runway’ lights across the fields could guide him on his way.
Only twelve ‘Oil QF’s’ were built in Britain and two of these were in Essex, guarding the oil refineries at Thames Haven and Shell Haven. But the difficulties that these sites had faced meant that they had a late start and just one, ‘near the mouth of the Thames’, was eventually attacked in 1944.
Five naval decoys were controlled by the dockyard at Harwich. Two, at East Mersea and Point Clear, were established to protect the naval facilities at Brightlingsea. These were QL/QF sites with the capability not only to attract bombers away from the town with dummy lighting but also to continue the deception with blazing ‘buildings’. Sites at Walton-on-the-Naze and Kirby-le-Soken, for the protection of Harwich itself, were similarly equipped. The fifth site, at Wix, shadowed the Naval Mine Depot by the River Stour at Wrabness.
In April 1942, the Luftwaffe began to launch attacks against Britain’s historic cities, the "Baedeker" raids. As a response to this, a programme to construct ‘Temporary Starfish’ to protect the most likely targets was immediately put into operation. Within weeks the first of these were in position, among them sites at Little Baddow and Great Bromley for the defence of Chelmsford and Colchester. The term "temporary" is somewhat misleading as the sites were in fact in every way as permanent as the earlier Starfish, although they were equipped solely with basket fires rather than the full range of effects.
In all, sixteen decoy sites were built in Essex. Although nothing remains of the actual decoy apparatus, a number of the control bunkers survive, protected as Scheduled Monuments and now recognised for the secret and vital role they played during World War Two.
© Fred Nash, ECC