The Deception Plan - Operation Fortitude

The deception plan for D-Day was based on the premise that, while everyone, on both sides of the Channel, knew an invasion would happen, precisely when and where it would occur was not known. Montgomery's 21st Army Group Headquarters included a small organisation known as R Force, responsible for ensuring:

 - the real preparations on the south coast opposite Normandy were as well hidden as possible;

 - that German attention was fixed elsewhere.

A major deception scheme was therefore mounted, known as Operation Fortitude. This aimed to suggest that the Allied plan was for a limited invasion sailing from Scotland to liberate southern Norway, followed by main landings across the Dover Straits to liberate the rest of Europe. Operation Fortitude North involved the display of a build-up of dummy aircraft on Scottish airfields - there were more than enough real ships in the Scottish ports not to need dummies. Four squadrons of dummy Boston light bombers were assembled on Scottish airfields, with two hard-working real Bostons seen flying intensively around the relevant bases and ensuring plenty of radio traffic that could be picked up by the Germans. Similarly, fake army radio traffic suggested that a fictitious "Fourth Army" was mustering in the north.

However, the main effort was placed on Fortitude South, to fix German attention on the "obvious" invasion target of Pas de Calais, as the nearest French coastline to the UK. While camps and assembly areas for the real invasion force around Portsmouth/Southampton and the south-west ports were the subject of extensive camouflage work to hide them from German reconnaissance aircraft, military facilities in eastern and south-eastern England were deliberately allowed to have their camouflage deteriorate or be implemented clumsily so that they became more easily detected. As thousands of military vehicles gathered on the south coast, hidden as much as possible from view, other vehicles were moved into eastern England and parked less carefully in visible groups or along roadsides. As in Scotland, carefully faked radio traffic suggested that twelve imaginary assault divisions were mustering in the east and south-east of England, with General Patton making high profile visits to units of the non-existent "Fourteenth US Army".

One of the most intensive efforts went into simulating the assembly of the Pas de Calais "invasion fleet". Every available landing craft was of course needed for the real invasion. So, under Operation Quicksilver III, large numbers of dummy Landing Craft Tanks (LCTs) kits were produced. The idea was to simulate the assembly of an invasion fleet in East Anglia and its gradual move down the coast to Dover and Folkestone in readiness for the final assault on Calais. Two infantry battalions - 4th Battalion The Northamptonshire Regiment and 10th Battalion The Worcestershire Regiment - were sent to a special training school set up at the village of Waldringfield on the River Deben to be taught how to assemble, float and maintain the dummies. The dummies themselves, offically called Devices No36 and No52, but codenamed Bigbobs, comprised canvas stretched over a lightweight steel tubular frame, floating on an array of 45-gallon oil drums. Building the Bigbobs was very labour intensive; each kit had over 500 parts, filling six or seven 3-ton trucks, and took 20 men six hours to assemble. When complete, it weighed eight tons, and looked convincingly like a real Landing Craft Tank Mark II (Device No36) or Mark V (Device No52).

A flotilla of Bigbobs

There were six main Bigbob sites chosen. 4th Northants manned Yarmouth, Lowestoft and the River Deben, while 10th Worcesters took care of the River Orwell, Dover and Folkestone. From 1 May 1944, Bigbob kits were delivered direct to the ports as fast as the factories could produce them, arriving at a rate of eight per day. At all of the sites except Yarmouth and Lowestoft, secrecy required the dummies to be assembled and launched into the water at night - if a German aircraft or agent had spotted a part-assembled kit on the shoreline, the plan would have been blown.

The two battalions began launching their Bigbobs on 20 May. 255 were used in all - Yarmouth had 49, Lowestoft 20, the River Deben around Waldringfield had 59, the Orwell 63, Dover 46 and Folkestone 18. The Royal Navy helped moor the dummies, while small Army boats were used for the constant work of maintaining their relatively frail structures. The sites at Lowestoft and the Orwell were well protected from the weather, but a lot of hard work was needed at the other sites, where wind and tides could play havoc with the Bigbobs. Nevertheless, damage was quickly repaired and dummies moved back to their correct locations when ever they drifted or were washed ashore. Great attention was paid to detail. Tins filled with waste oil and rags were burnt at the stern of some vessels to simulate cooking smoke from the galley, sailors' washing was hung out to dry on decks, rust marks were painted onto the "hulls", and small quantities of waste oil were deliberately spilt onto the water.

On the night of 5/6 June, while the invasion fleet headed for Normandy, German radar was given plenty to look at in the Dover Straits. Small flotillas of motorboats, fitted with radar reflectors and transponders to make them seem much larger, headed towards the French coast between Boulogne and Le Havre, while 16 Lancasters from 617 Squadron (the Dambusters) and 6 Stirlings from 218 Squadron flew intricate and very precise patterns overhead, dropping a dense screen of Window radar-reflective aluminium strips. The overall result on German radars was the impression of very large formations of ships headed for the Pas de Calais area. Five small Royal Navy motor launches fitted with cinema loudspeakers crept to within three thousand yards of the coast during the night to play soundtracks of ship engines, shouting of orders, landing craft being lowered and ships being anchored, to give the impression to the German coastal defences of an assault force readying itself for the final assault. The Calais defences reacted as desired and coastal batteries and searchlights went into action against the phantom fleet, while Luftwaffe night-fighters searched in vain overhead.

Other Bomber Command aircraft carried out four airborne diversions codenamed Titanic, simulating the drop of paratroops in the area of the Seine and to the east and south of Caen to distract attention from the real airborne assaults. Large numbers of dummy paratroops made out of hessian and filled with sand, each 2ft 6in high and weighing 13lb, descended on small parachutes, appearing suitably realistic in the dark. Many of the dummies were fitted with pyrotechnics that could simulate rifle or machine gun fire, with time delays of up to two hours, while aircraft also dropped delayed action signal flares.

It might be thought that all this activity ceased on 6 June once the real invasion had come ashore. On the contrary, efforts were redoubled. Perhaps the greatest success of the Allied deception plan was that even after the troops had landed in Normandy, the Germans believed for several weeks that these were in fact a diversion, and that the real invasion, on an even bigger scale, was still planned for Calais in mid-July. As a result, they held back most of their reserves, rather than rushing them straight to the fighting in Normandy during the critical first few days. From 8 June until 12 July, clever use of lights during the night and vehicles moving around on the beaches or in the ports gave the impression that an intensive embarkation operation was underway at the Bigbob sites, loading assault troops into the landing craft. The Bigbob fleets were lovingly maintained throughout the summer, only finally being removed in August.

Last Updated: 9 Aug 04