D-Day Planning WW2

D-Day landings June 6 1944 during World War 2 (WW2).

The most well-known beach landings of WW2 were the D-Day landings in Normandy, France on June 6 1944. Known as Operation Overlord, this was the largest seaborne invasion in history. It involved 160,000 Allied troops landing on five beaches: Utah, Omaha, Gold, Juno and Sword.

By 1944 German Army and Axis forces’ occupation of mainland Europe during WW2 was virtually complete. British, American and Commonwealth forces had to mount an amphibious assault if they were to liberate mainland Europe from occupation.

Did You Know?

‘Axis’ partners were Germany and Italy in Europe and Japan in East Asia. ‘Allied’ powers were Great Britain, the United States, the Soviet Union and China. However, like today, Axis and Allied partners did not always share common aims, or agree how the war should be fought!

WW2 plans to take back Europe from the invaders needed to ensure as few lives as possible were lost. They were keen not to repeat military mistakes made during similar assaults, like the Gallipoli campaign in WW1 and Dieppe raids earlier in WW2.

Exercise Fabius was a major D-Day rehearsal instigated by Winston Churchill in May 1944. The exercises was designed to test cooperation between naval, air and ground forces, including landing craft, specialised armour and infantry.

Four south coast beaches were chosen for practice battles for the invasion of Europe at Hayling, Bracklesham Bay, Littlehampton and Slapton in Devon. These took place from 3 to 8th May 1944 and involved 25,000 British, American and Canadian troops.

Exercise unloading a landing craft tank (LCT) at Amber I beach in Bark South

There was also a desperate need for detailed information before any invasion an d it was the Hayling-based COPP teams that got onto the enemy beaches and coasts. They carried out the critical surveys that supported Allied invasion plans throughout WW2, and particularly D-Day in 1944.

Four critical questions were faced in planning for a successful D-Day invasion:

  • What navigational hazards were hidden beneath the water just offshore?
  • Would beaches be firm enough to take the weight of heavy tanks?
  • Were there exit routes off the beach once assault forces had landed?
  • What defences did the enemy have on the coast or on the beaches?

Aerial reconnaissance helped knowledge of foreign army forces, as well as observations carried out from sea. But to get detailed information needed for a full invasion, the military needed observers to actually visit the enemy beaches.

Omaha Beach D-Day landing map with detail provided by COPP teams
  • Why COPP teams were created and what they did – read more
  • Read about COPP team exploits from 1941 – 1945 in WW2 – click here