It comprised a vast amount of concrete, formed into honeycombed caissons: the largest as big as a five-storey block of flats. These were to become the “Mulberry Harbours”, through which equipment and provisions for the invasion of Normandy would be landed.
After the Dieppe disaster of 1942, it was accepted by the Allies that capturing actual ports on that heavily defended coast was all but impossible. The invaders would instead have to construct temporary harbours, two of them, each the size of Dover.
To this end, the “Phoenix Caissons”, as they were known, had been sunk, or parked, on the English seabed in early 1944, awaiting their moment. When that came, their hollowed compartments would be pumped out and the blocks would rise – hence the “Phoenix” part of the name – before being towed across the channel. That was the theory, anyway. The practice proved much more problematic. And had it not been for the heroics of a now-forgotten salvage expert from Co Down, with the help of a well-timed accident involving one of the caissons, the operation might have been a disaster.
The salvage man’s name was John Polland, originally MacPolin, and he was an odd candidate to become a saviour of the Royal Navy. The MacPolins were a staunchly nationalist family from Portaferry. A previous generation’s naval experience had included internment on the HMS Argenta, in Belfast Lough, during the 1920s.That was the fate of John Polland’s father, “lifted” in lieu of his brother Donal, who had been a member of a local IRA flying column.
To read more on this intriguing back story to the D-Day landing operations click here.