Getting people and machinery to France was in some ways the easy bit of D-Day. Keeping them supplied when they got there was a lot harder. The War Office estimated that 60 per cent of all supplies by weight needed in France took the form of petrol and oil alone, so how were they going to get it there? The obvious solution was tankers, but there were concerns that deep-water facilities in Europe would be destroyed and shallow-draught ships might struggle in the choppy waters of the English Channel, especially under enemy fire.
Some fuel could be brought in jerrycans – 20 million of which were prepared for the journey – but what was needed was a backup and that took the form of one of the war’s most overlooked engineering marvels: Pluto – the PipeLine Under The Ocean.
Laying a pipeline across the Channel was no mean feat. Such distances had never been covered before and had never operated in such busy or rough tidal waters. Added to that, the enemy would...