PLUTO was an ambitious plan to supply fuel to Normandy using an underwater pipeline. Knowing that vast quantities of fuel would be required to supply vehicles in France, Allied planners decided to lay a pipeline along the seabed of the English Channel, from the Isle of Wight to Cherbourg. It was hoped that by mid-August 1944, PLUTO could supply 1 million gallons of fuel a day.
In the event, PLUTO was not ready until late September and only managed to supply 700,000 gallons before the pipeline failed. By then Allied land forces had advanced well beyond Normandy. The Isle of Wight pipeline was abandoned, but a new pipeline from Dungeness to Bolougne was more successful.
Fieldwork identified and recorded the remains of several sections of pipeline that had been laid between Lepe on the Hampshire coast, and Thorness Bay on the Isle of Wight. Several of these had been laid for training purposes and were recovered after the war. At the National Archives, previously unseen aerial photographs were discovered that appear to show the first trials of the ‘Conundrum’ pipe layer taking place off Hengistbury Head. The Conundrum, a huge ‘cotton reel’ that unwound the pipeline onto the seabed, was later used to lay the pipeline to France.