"WHat was some surprising insight from an 1970's wargaming simulation of "Operation Sealion" The German Invasion of England in WWII

 

I pulled this off Quora, I saw it taking a "Microbreak" at work surfing the phone. so I shamelessly clipped it.

In 1974, surviving WWII commanders wargamed Hitler's invasion of Britain and made a darkly comedic discovery: the Royal Navy wouldn't even need to fire its guns to sink the German fleet.

The highly detailed simulation of Operation Sea Lion was held at the Royal Military Academy Sandhurst and featured actual combat veterans making the decisions, including Luftwaffe General Adolf Galland and Kriegsmarine Admiral Friedrich Ruge.

The wargame yielded several unexpected insights, starting with the initial assault. Most historical assumptions suggest the Royal Air Force and Royal Navy would have crushed the invasion fleet before it ever reached the beaches. Instead, the Sandhurst simulation showed that the Germans would have successfully landed around 90,000 troops in Kent and Sussex. Because the British Army had abandoned most of its heavy equipment during the evacuation of Dunkirk just months earlier, the coastal defenses were too weak and disorganized to stop the initial beachhead. The German army quickly pushed inland, capturing their early objectives.

But the success was short-lived, largely due to the fatal flaw in German logistics. The Kriegsmarine lacked purpose-built landing craft, forcing them to commandeer hundreds of flat-bottomed river barges from the Rhine to transport men and supplies across the English Channel.

Once the British realized a full-scale invasion was underway, the Royal Navy unleashed the Home Fleet from Scapa Flow. When the British cruisers and destroyers arrived in the Channel, they found that they did not need to rely on their main guns to destroy the German supply lines. Simply steaming through the invasion flotilla at high speed would generate enough wake to swamp and capsize the flimsy, unseaworthy river barges.

With the Channel completely severed by the Royal Navy and the RAF, the 90,000 German troops who had successfully landed were suddenly trapped. Cut off from food, medical supplies, and artillery shells, their advance ground to a halt. The Luftwaffe suffered massive losses attempting an improvised aerial resupply. Facing a fully mobilized British defense and completely out of ammunition, the entire German invasion force was compelled to surrender within six days, proving that without absolute naval and air supremacy, Sea Lion was a guaranteed trap for the German army.

German invasion barges, many of them commandeered river vessels, waiting at Boulogne Harbour in France during the Battle of Britain. Source: Wikimedia Commons.