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OPERATION MULBERRY
(D-Day 1944)

 
Winston Churchill gives 'V' sign

Winston Churchill issued the order:

"We require piers for use on the beaches.
They must float up and down with the tide.
The anchor problem must be mastered.
Do not argue the matter - Let me have the solution worked out."

   A major port was required to land all the equipment needed to win the battle for Normandy and the liberation of France.

   At the Roosevelt-Churchill conference in Quebec in August 1943, it was decided that an artificial harbor would be built and towed across from England to France.

In the fall of 1943, General Eisenhower's planners realized the need for the rapid insertion of combat supplies and soldiers to sustain the fighting in France following the Normandy Invasion.

   Ships were the only feasible means to transport the enormous quantities of supplies and equipment needed to defeat the Germans.  After months of debate, the planners decided to construct two artificial harbors, code named "OPERATION MULBERRY."

   The construction of harbors was a massive undertaking and required the use of 158 tugboats.  The Army Transportation Service (ATS) supplied 74 ST small tugs and 6 LT large tugs.

   In preparation for the operation, the Army tugs sailed across the Atlantic Ocean to England.  This was no easy task for the small ST-type tug, which only measures 86 feet long.  The ATS was also instrumental in recruiting and organizing Merchant Marines and civilians to help man the Army tugboats, and sail the blockships, "Gooseberries," to their scuttling position.

Army Tugs at Normandy

   U.S. Army Transport Service crews operated small tugs that towed barges to Normandy from England,  and worked to build the British and American mulberries.

ST 247

ST 248

ST 338

ST 344

ST 758

ST 759

ST 760

ST 761

ST 762

ST 766

ST 767

ST 769

ST 770

ST 771

ST 773

ST 781

ST 794

ST 795

   Construction began off Omaha Beach at 0600 on June 7, 1944, with the emplacement of the Gooseberries under heavy enemy fire.   When completed, the harbor had 3 half-mile long floating roadways, 6 Lobnitz piers, over 3 miles of caissons and sunken ships for a breakwater, and a "Bombardon" floating barrier.

    By June 14th (D-Day + 8), Mulberry A, the American Mulberry, was established, and in just four days of full operation 11,000 troops, 2,000 vehicles, and 9,000 tons of equipment and supplies were brought ashore.

   Beginning on June 19th, the worst storm to hit the English Channel in 40 years pounded Mulberry A for three days, leaving it in ruins.  The damage inflicted upon the harbor was so severe, that repairs were impossible.  Parts that could be salvaged were taken over to Gold Beach to repair the British harbor, Mulberry B.

   Had it not been for the success of "Operation Mulberry" during the early days of the invasion, the Allies may not have been able to keep the foothold they fought so hard to earn on D-Day.

GOOSEBERRY

   "Gooseberry" was the name given to the artificial harbor's sunken ship breakwater.   The Gooseberry was made up of old Victory ships and "rust buckets" left over from World War I, totaling 59 ships. 

   The primary purpose of the Gooseberry was to protect a portion of the shore from waves so that landing ships could safely anchor on the beach.

While constructing the Gooseberry, Army sailors and Merchant Marines would steer the old ships close to shore, carefully avoiding underwater mines and continuous enemy shelling.  Once in position, the small crew on board would detonate explosive charges in the hull to scuttle the ship in position.  While the ship sank 15 to 20 feet, Army tugs would hold it in position against the current.

   During the 19 June 1944 storm, the Gooseberry blockships held their position in the artificial harbor.  The servicemen who were working on the Mulberry took shelter on the Gooseberry while waves from the storm crashed over the sunken ships.  Following the storm, the Gooseberries were the only part of the artificial harbor that remained intact.

 

sunken ships forming a breakwater

Above, the blockships were sunk in shallow water and would appear to still be afloat.   Here, many smaller ships used the Gooseberries as mooring points.

storm on Gooseberry

PHOENIX CAISSONS

 

concrete and steel casings for Phoenix under construction


Phoenix Rising - Dwight C. Shepler
 

   The caisson was made entirely of concrete and steel.  It came in three sizes, the largest measuring 200-feet long and 60-feet high.  It was named "Phoenix" after the fabled bird because it could be resurrected by closing its flood valves and pumping out the water.  Over 150 of these massive structures were built around England in time for the D-Day invasion. 

   Beginning on D-Day, one of the largest towing missions in history took place when 85 tugs, each with a Phoenix, started the long haul across the English Channel.   Due to the size of the load and the conditions in the Channel, the tugs were limited to a maximum speed of 5 miles-per-hour.  Each caisson had a small crew that would man an anti-aircraft gun for protection, and operate the flood valves.

Once in position, the crew opened the flood valves and the Phoenix  slowly sank 15 feet to the sea floor.  The Army ST tugs held the massive caissons in position against the current as it sank.   At times, the current was so strong that four tugs were required to hold the caisson. 

   The caissons were the main protective breakwater for the pier portion of the Mulberry harbor.  When placed end to end, the Phoenix caissons created a breakwater over 2 miles long.

86 ft tug beginning the trip across the English Channel

LOBNITZ PIERS

floating pier 'Lobnitz' underway

   The "Lobnitz" pier was the key component of the harbor that made downloading a ship in 60 minutes possible.  Named after its inventor and manufactured in Scotland, the pier was designed to float up and down on its 60-foot spud legs with the tide.    The Army ST tugs were used to position the Lobnitz pier at the end of the "Whale," the floating causeway. 

color drawing of Mulberry pier at work

   The "spud" pier, as it was known to the sailors, was floated into position like a barge with its legs completely raised into the air.  Once attached, the operators would lower the spud legs to the sea floor anchoring the pier and the causeway in place while still allowing the pier platform freedom of motion up and down. 

   The pier crew would continuously adjust the height of the pier to match the tide, this revolutionary capability allowed supplies to be brought ashore continuously, regardless of the tide.

THE WHALE

   Leading from the Lobnitz pier to shore was a half-mile long floating causeway called the "Whale."  The "Whale" was made of 80-foot long steel bridge sections that would float on a pontoon, named a "Beetle," at each end.

diagram of shore and floating whale - Normandy Beaches

   As depicted above, the "Whale" would rise and fall with the tide.  Since each section was flexible, the causeway could adapt to tidal conditions and still maintain its ability to sustain heavy traffic.

   Mulberry A had three Whale causeways, two that could sustain a 25-ton load and one that could hold up to 40 tons for tanks and other heavy equipment.  

whale assembly prior to towing across English Channel

   Up to four sections were attached together for the trip across the English Channel.  The Army ST tugs were responsible for towing numerous sections of the "Whale" and putting it together off Omaha Beach.

the floating pier/whale at Mulberry

THE STORM 
JUNE 19, 1944 
 
 

the storm that ended Mulberry

   Beginning on June 19, 1944, the worst storm in forty years hit Mulberry A.  The storm's sustained Force-6 gale winds produced waves over 100-feet long, eventually overwhelming the harbor's breakwaters. 

   On the first day of the storm, the focus was to prevent large ships and other loose vessels from colliding with the Whale; this soon proved to be futile.

   By the second day of the storm, the effort to save the harbor was abandoned and the order was given for "all hands to save themselves."   Many Army tugs continued to work through the storm.  They were instrumental in saving large ships that broke loose from their moorings and rescuing crews stranded on the Gooseberries. 

   Following the storm, the War Department decided not to reconstruct Mulberry A.   The available resources were already depleted prior to the storm.   Instead, the salvageable parts went to Mulberry B, which was still under construction. 

   Overall, Mulberry A was an enormous success.  The massive amounts of supplies brought ashore during the few days of operation assisted the Allies in maintaining the beachhead and defeating the Germans.

color drawing of the end of Mulberry

ARMY WATERCRAFT AT NORMANDY

U. S. Army Transports that carried troops to Normandy from England
during June 1944:

 
USAT Borinquen

USAT Borinquen
7,114 tons, 1931
capacity: 1,289 troops

 
USAT Excelsior

USAT Excelsior
7,618 tons, 1943
capacity: 2,113 troops

 
USAT George S. Simonds

USAT George S. Simonds
8,358 tons, 1915
capacity: 1,803 troops

 
USAT Goethals


USAT Goethals
12,903 tons, 1942
capacity: 1,976 troops

 

 

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