'The longest day'
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 View of Courseulles with DUKWs landing stores, by Stephen Bone. © NMM |
The Allies landed on five beaches on Normandy on D-Day, 6 June 1944. For the Allies, this came to be known as 'longest day'.
This was the greatest amphibious operation in history. It involved nearly 4,800 vessels, including over 2,000 landing craft.
It was a masterpiece of organisation: 330,000 men and 50,000 vehicles were put ashore in the first week alone.
Throughout the D-Day campaign, it was vital to keep up the constant supply of troops and equipment. Until the Allies could capture a port to unload ships, they needed to find other ways to keep the troops supplied. Artificial harbours and secret pipelines were built for this purpose.
Caissons for the Mulberry harbours
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| A Phoenix caisson under construction. © NMM |
The artificial harbours or ‘Mulberries’ allowed ships to be unloaded close to the beachheads.
Their main components were the ‘Phoenix’ caissons. These were specially constructed concrete blocks of different sizes, some weighing 5,800 tonnes.
Over 200 caissons were built, requiring over 2 million tonnes of steel and concrete, and employing 20,000 workers.
Many caissons were built in the port of London. The East India Import Dock was drained and the contractors McAlpine built eight caissons there. Others were built in South Dock in the Surrey complex, the Royal Docks and Tilbury, and 17 specially constructed sites excavated along the banks of the Thames.
Assembling the Mulberry Harbours
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| The ocean-going rescue tug HMS Growler. © NMM |
The components for the Mulberries had to be assembled in the Solent under strict secrecy.
A team of 160 ocean-going tugs towed them to Normandy after D-Day.
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| The gooseberry, Courseulles, by Stephen Bone. © NMM |
The first task was to form an artificial breakwater or ‘gooseberry’ by sinking dozens of old vessels. This formed an outer protective ring for the Mulberries.
Finally, the caissons were sunk off the beaches to form two complete harbours.
The Mulberries in place
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| Mulberry harbour, Arromanches: Normandy landing, June 1944, by Stephen Bone. © NMM | One Mulberry was at Arromanches in the British and Canadian sector of Normandy; the second was at St Laurent in the American sector.
At any one time, each could accommodate up to seven Liberty Ships – the 10,500-tonne general cargo ships produced in large numbers in American dockyards.
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| Mulberry harbour, Arromanches: Normandy landing, June 1944, by Stephen Bone. © NMM |
Unfortunately, the St Laurent Mulberry was damaged by freak storms at the end of June and never functioned at full capacity.
The Arromanches Mulberry was soon handling 12,000 tonnes of supplies each day. It was as large as the harbour at Dover, and remained in use even after the Allied forces captured conventional ports.
PLUTO
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| PLUTO pipes laid out for winding on the drum. © NMM |
The Overlord planners knew that the Allied armies would need huge quantities of fuel to keep them mobile.
However, they did not want to use large numbers of tankers to ferry the fuel across the Channel. Tankers were too vulnerable to mines and attacks by aircraft or u-boats.
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| The drum to carry the PLUTO pipes. © NMM |
The solution was to construct an underwater pipeline or PLUTO – Pipeline Under the Ocean – to pump fuel directly to France.
Most of the pipeline was made on the Thames, either at the Callender Works at Erith or the Enderby plant in Greenwich.
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| The recovery of PLUTO: men standing on a huge cone of pipes. © NMM | With more than 1250 km of pipe in 17 different lines, PLUTO carried nearly 800 milllion litres of fuel to France.
The scale of the PLUTO can be appreciated from a series of shots taken after the war, when the pipelines were recovered to obtain the valuable lead they contained.
The Thames barges and D-Day
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| Landing Barge Vehicles awaiting reconversion in 1946. © NMM |
A final mention should go to the humble Thames barge. As much shipping had been diverted to the west coast, many Thames barges became redundant after the Blitz.
The Royal Navy converted over 1000 into support craft. Most became LBVs (Landing Barge Vehicles). These were used mainly to carry vehicles and supplies from ship to the shore.
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| A Landing Barge Kitchen for D-Day. © NMM |
In preparation for D-Day, some converted barges were given specialist roles.
Perhaps the most popular were the LBKs (Landing Barge Kitchens), which fed the craft that supplied the troops in Normandy.
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