Pluto was Pipeline Under The Ocean, vital arteries that pumped millions of gallons of fuel from Britain to Allied forces in France.
Two lines were built, codenamed Dumbo and Bambi. Pumping stations were disguised as ice cream shops, garages and bungalows.
The sea bed cables were laid by 30ft diameter Conun drums pulled by tugs.
This is one of more than 1,000 secret photographs of the pipeline operation newly released and available to be viewed free at The National Archives in Kew.