When Mountbatten was appointed to Combined Operations, he was given a brief to initiate a programme of raiding against the French coast. This resulted in the construction of ‘hards’ for loading landing craft during the summer of 1942, initially along the south coast then extended to South Wales in the west and Felixstowe in the east. As part of FORTITUDE SOUTH, a layout for dummy landing craft using these existing hards as well as other sites was proposed in April 1944 in the Eastern Command area with the intention of indicating a passage and concentration of assault craft from Yarmouth to Folkestone (part of QUICKSILVER).
In Eastern Command the suggested layout for dummy landing craft (known as ‘Bigbobs’ ) was as follows:
Sites, including fields for storage of Bigbobs and tented accommodation, had to be requisitioned and improvements to existing hards made to enable the launching of the dummy craft. For the Orwell and Deben sites, 185 Field Company, under command of 13 GHQ Troops Engineers, was made available to carry out this work.
Right: Bigbob sites, River Deben and Orwell
Responsibility for this operation from Yarmouth to River Deben was with the 4th Northants and from River Orwell to Folkestone with the 10th Worcs. These battalions were in place by the end of April. Stores began to arrive and were laid out regularly to suggest ordinary store dumps with recognizable parts of the superstructure, such as funnels, covered over. The first Bigbob was launched on May 20th, as part of a phased programme, with eventually a total of 255 launched. The phased programme of launching was as follows:
Bigbobs were constructed using a tubular scaffolding frame, fitted with oil drums for floatation and a painted canvas finish. Funnels, ventilators etc were also added. The drums were added at the last possible moment and brown hessian sheets or other such available material draped over to disguise the skeleton outline of the craft.
Above: Dummy Landing Craft on River Orwell
Before any Bigbob could be launched, the approval of the senior local Royal Navy officer had to be obtained. At Yarmouth, Lowestoft, Orwell and Dover trots were laid for the berthing of the dummy craft but were insufficient for the envisaged programme of launching. The Royal Navy was to advise on the use of real berths dependent upon the need of operational shipping. All launching was to be carried out during the hours of darkness except at Yarmouth and Lowestoft when it could take palace in daylight hours if so required. While the craft were at their berths, steps were to be taken to ensure that they were maintained and also to give the impression they were being “lived in” or animated.
The deceptive lighting, part of the cover plan FORTITUDE SOUTH was closely timed to support this build up of deceptive craft and was turned on D+2 to give the impression of a force assembling for invasion in the Pas de Calais area.
By mid-August, FORTITUDE was under review and although not closed down was maintained at a level that required much less resources. The 4th Northants were withdrawn from Bigbob sites and responsibility for all sites taken over by 10th Worcs. Bigbobs were to be dismantled, firstly at Dover followed by other sites. All work was hopefully to be completed by 1st October.
As well as dummy landing craft, dummy tanks / vehicles were used – e.g. near Flixton dummy tanks were used to replace the real ones which had departed to take part in D Day. Dummy lights were also used to represent army convoys – a light decoy site at Carlton Colville was set up on marshes to represent a convoy heading towards Lowestoft at night. The grass blowing over the bulbs gave the illusion of movement.
Decoy sites, wartime deception in Norfolk and Suffolk, H Fairhead
Fields of Deception, C Dobinson, Methuen, 2000
OVERLORD, Camouflage and concealment – FORTITUDE, TNA