D-Day: the largest seaborne invasion in History

D-Day overlord map

From Maritime Executive

The Normandy landings on June 6, 1944, (D-Day) were the largest seaborne invasion in history.

The operation, codenamed Operation Neptune, began the liberation of German-occupied northwestern Europe from Nazi control and contributed to the Allied victory on the Western Front.

The amphibious landings were preceded by extensive aerial and naval bombardment and an airborne assault.

The landing involved 24,000 American, British and Canadian airborne troops shortly after midnight.

Allied infantry and armored divisions began landing on the coast of France at 06:30. 

 A LCVP (Landing Craft, Vehicle, Personnel) from the U.S. Coast Guard-manned USS Samuel Chase disembarks troops of Company E, 16th Infantry, 1st Infantry Division (the Big Red One) wading onto the Fox Green section of Omaha Beach (Calvados, Basse-Normandie, France) on the morning of June 6, 1944.

American soldiers encountered the newly formed German 352nd Division when landing.

During the initial landing two-thirds of the Company E became casualties.

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The target 50-mile (80 kilometer) stretch of the Normandy coast was divided into five sectors: Utah, Omaha, Gold, Juno and Sword Beach.

Strong winds blew the landing craft east of their intended positions, particularly at Utah and Omaha. While the weather on D-Day was far from ideal, postponing would have meant a delay of at least two weeks, as the invasion planners had requirements for the phase of the moon, the tides, and the time of day that meant only a few days in each month were deemed suitable.

Omaha Beach East map

The Army Map Service, an NGA predecessor, provided maps for the Normandy invasion

and throughout World War II. 

The Army Map Service, a DMA predecessor, met the challenge of providing maps for the Normandy invasion, as well as all of World War II.

During that time, the AMS operated 24 hours a day, six days a week and maintained a skeleton crew on the seventh.

It successfully met every mapping request worldwide.

During the four-year period, 1941–1945, the AMS prepared more than 40,000 different maps of all types. (example)

Many of these were maps of areas never mapped before, prepared and brought up to date by aerial photography obtained by Allied forces aircraft, flying bombing missions.

Normandy invasion required about 3,000 different maps with a total of 70 million sheets.

The total production of maps by the AMS during WWII was approximately 500 million sheets.

If stacked one on top of another, they would reach about 31 miles high, 134 times the height of the Empire State Building.

The men landed under heavy fire from gun emplacements overlooking the beaches, and the shore was mined and covered with obstacles such as wooden stakes, metal tripods and barbed wire, making the work of the beach-clearing teams difficult and dangerous.

Adolf Hitler placed German Field Marshal Erwin Rommel in command of German forces and of developing fortifications along the Atlantic Wall in anticipation of the invasion.

The Allies failed to achieve any of their goals on the first day. Carentan, St. Lô, and Bayeux remained in German hands, and Caen, a major objective, was not captured until 21 July.

Only two of the beaches (Juno and Gold) were linked on the first day, and all five beachheads were not connected until 12 June.

However, the operation gained a foothold which the Allies gradually expanded over the coming months.

Losses to merchant ships during the invasion were much lower than had been anticipated.

Many ships plied back and forth between English ports and the beaches at Normandy.

Some ships made as many as three trips in June alone.

 'Mulberry' artificial harbour in Arromanches (SHOM map with the GeoGarage platform)

The U.S. Naval History and Heritage Command describes how a modern, artificial port was built at Omaha and Utah beaches.

Armed Guards on some 22 merchant ships which were scuttled to make a breakwater played a vital part in the operation.

For days they endured the early fury of the German counter-attack and helped give fire protection to the forces ashore from their partly submerged ships. 

Normandy landing : first assault

source : DDay Overlord website

Carrying out the time-honored task of saving lives, albeit under enemy fire on a shoreline thousands of miles from home, the U.S. Coast Guard’s cutters involved in the invasion of Normandy saved more than 1,400 souls, but the day was also one of the bloodiest days in Coast Guard history.
German casualties on D-Day were around 1,000 men.
Allied casualties were at least 10,000, with 4,414 confirmed dead.

Links :

• BBC : D-Day: How was the biggest ever seaborne invasion launched?
• CNN : D-Day: Debunking the myths of the Normandy landings
• Chron : D-Day: The Invasion of Normandy in color photographs 
• BBC : Animated Map: Operation Overlord
• Mashable : D-Day weather map is most important in History (Weather support of the Normandy invasion)