Preparing for D-Day

1. Vacation Photos and Postcards collected by the French Resistance and used by the allied planners. How would these be useful in planning Operation Overlord?

The first key decision was to choose the location of the invasion beaches. Planners collected postcards from people who had been to Normandy on holiday for photographic evidence as to what the coast looked like. This helped them to plan the best landing sites and map the areas eventually chosen.

2. How might this diving suit have aided the planning of Operation Overlord?

To make sure the beaches could handle the weight of the tanks, trucks and other vehicles that would take part in the invasion, men were sent ashore from submarines to collect samples of sand. This diving suit was used by a Lieutenant to collect samples from the potential landing beaches.

3. Tidal calculating machine, tidal calculations, and a weather report. Why do the allied planners need this information?

The tides and weather predictions were carefully analyzed to give the best chances for success. It was determined that the optimal tidal conditions for invasions were low tide at dawn. This was to due to the nature of the German defenses along the beaches of Western Europe. The Germans had built an extensive line of fortifications along the beaches that included bunkers, barbed wire, mine fields, and anti-tank ditches. Their defenses also included tens of thousands of beach obstacles meant to stop Allied landing craft. At low tide, these obstacles were fully exposed on dry beaches, posing no threat to approaching landing craft. But at high tides, these obstacles would be partially or fully submerged, posing a great danger to approaching landing craft. In addition, allied planners wanted weather that was not cloudy or overcast. Prior to GPS guided weapons, all bombing was done by sight. In cloudy conditions aerial and naval bombs could not be sure they were hitting the correct targets.

4. Strips of Aluminum -How will this be used to trick Hitler?

The Allies used various tactics to try and convince the Germans that the landings would be at Calais. This photo shows a factory worker producing foil, code- named “window”. “Window” was strips of aluminum which were dropped by aircraft in order to confuse German radar.

5. Unloading equipment in Normandy days after the first landing. How were these docks and harbors constructed so quickly?

A large number of supplies and equipment would need to be unloaded quickly and until a port could be captured, the Allies needed a method to get everything ashore. Prefabricated harbors were built in Britain, then towed across the English Channel. Each harbor, when fully operational, had the capacity to move 7,000 tons of vehicles and supplies per day from ship to shore.

6. An example of a PLUTO (pipeline under the ocean) What travelled in these enormous pipelines?

To provide enough fuel for the thousands of vehicles in France a plan was devised to lay a pipe under the sea and pump the petrol across from Britain. This photo shows the large drum of pipe ready to be laid on the sea floor. Ultimately, 17 pipelines could deliver, one-million gallons of fuel each day and Allied success was assured.

7. This is fake equipment made of rubber. How were these used in the build-up to Operation Overlord?

Known as the “Rubber Army” or “Ghost Army”, the unit had a mission: to deceive the Germans into thinking Allied forces were in one location, while real U.S. troops advanced miles away. The allies sent deceptive messages, meant for German interception saying that units under the leadership of General Patton were preparing in parts of England nearest to Calais. The rubber equipment was moved daily so the German reconnaissance teams would think troops were performing maneuvers in the area. Meanwhile over a million real troops were gearing up in parts of England nearer to Normandy-the real target.