More than 140,000 troops defended 80 kilometers of coastline, but this is still very weak, almost a meter away from a little eight soldiers to defend, of course, the Allies can not launch an 80 kilometers wide offensive surface at the same time, which allows the defending German army to properly deploy troops after the start of the war, key areas can be defended by 2 to 3 soldiers per meter, and a soldier of two meters in dangerous areas. Pen "Fun" Pavilion www.biquge.info

The Führer Rommel attached great importance to the construction of defense in the coastal areas, and personally led a special delegation to inspect the coastal defense situation from Denmark, the Netherlands, and France, and specifically demanded that the forward defense should be pushed forward into the sea, starting from the high tide line, laying mines in the deep sea, and setting up obstacles in the shallow sea.

The beach is lined with jagged concrete cones, tank traps, and a large number of mines are laid in between, concealed fire points are built at the commanding heights overlooking the beach, and a large number of wooden piles are laid in the open area behind the beach to prevent aircraft landing.

The deployment of these explosives and obstacles, but the project is so huge that it is really impossible to complete, but the Normandy area has quietly done it, while the other areas have just done it in disguise and then abandoned it.

Historically, the German army was not only weak in the Atlantic defense line, but also there were always differences among high-ranking generals on the policy of resisting the landing. Field Marshal Rundstead, commander-in-chief of the Western Front, advocated the deployment of the main forces in depth and the use of counterattack tactics to resist the landing;

Field Marshal Rommel, commander of Army Group B, advocated deploying the main forces on the beachhead and relying on beach fortifications to annihilate the enemy on the beachhead. In the end, they had to adopt a compromise approach, deploying part of the troops on the beachhead and part of the troops in depth, which could not form a superior force whether it was on the beachhead or in depth, and was neither able to prevent the landing of the Allied forces on the beachhead, nor able to organize a counterattack, laying the groundwork for the defeat of the German army in Normandy in the future.

More seriously, due to the disagreement between the two men on the use of armored forces, Hitler was furious and transferred the four elite armored divisions of the mobile forces of the Western Front, which were originally under the command of Rommel, to the command of the Supreme Command, a decision that actually deprived the generals of the Western Front of the command of the armored forces, and deprived Rommel of the most terrifying counterattack force of the Allies, and in this case he could not be defeated.

Although Germany is in charge of Rommel, he still can't change the British and American Navy's complete sea dominance, although German submarines have taken the initiative several times to attack Allied transport ships, but the result is heavy losses, because Britain invented sonar, Germany's U2 submarine role is greatly reduced.

The Allied forces have achieved a complete victory in the anti-submarine escort in the Atlantic, ensuring that a large number of supplies and personnel transported from the United States mainland to Britain can safely cross the Atlantic.

Britain had become almost a large barracks, with nearly three million troops from eleven countries, every airfield was full of planes, and every port was crowded with ships. According to incomplete statistics, more than 5.3 million tons of various materials were transported from the United States to Britain.

In order to ensure a sufficient number of landing craft, Marshall, chief of the US Army General Staff, transferred a batch of landing craft from the Pacific Theater in spite of the Navy's strong opposition, and only then did he gather enough landing craft.

In order to fill the gap between the firepower of the naval guns and the landing of the troops, the Allies creatively loaded artillery and multiple rocket launchers onto the landing craft and converted them into fire support boats, which accompanied the landing craft to provide uninterrupted fire support.

In order to quickly break through the minefields and defensive positions of the German army, Major General Hobart, a tank expert of the British army, proposed to develop special tanks, form special armored units, land before the landing of sappers, suppress German firepower, clear minefields, destroy obstacles, and act as a pioneer.

Chief of the British General Staff Allen? General Brooke approved his proposal and tasked him with the specifics.

After several months of hard work, Hobart successfully developed a variety of special tanks such as amphibious tanks, "rotary" tanks for paving roads, mine-sweeping tanks, Spitfire tanks, bridge-building tanks, and engineer assault vehicles, and trained a group of special tank drivers, on the basis of which the British army formed the 79th Armored Division and appointed Hobart as the division commander.

The division conducted exercises on Norfolk Beach in England, which resembles Normandy, and the results were remarkable.

The British army invited the US military to watch the exercise, but Bradley, the commander of the US 1st Army, did not recognize the important role of these special tanks and did not purchase special tanks. As a result, in the face of the same strong German fortifications, the British army landed smoothly, and the American army suffered heavy casualties, for which Bradley was criticized by many people after the war, which is a later story. Of all the preparations, the biggest project is the artificial port. It was in charge of British Rear Admiral Tennant.

A total of two artificial harbors were built, codenamed Mulberry A and Mulberry B. First, 146 hollow concrete caissons, each 61 meters long, were built in eight different sizes depending on the depth of the sea water at the sinking site, with a minimum displacement of 1,772 tons and a maximum displacement of 6,044 tons.

The caisson contained a crew compartment, as well as 2 anti-aircraft guns. There is a floating tank that can be floated, and there is a sea valve to sink it, which can be sunk to the designated position in more than ten minutes after opening.

The caisson will not be able to propel itself, so it will be towed across the strait by a tugboat and sunk on the 5.5-metre isobath one nautical mile offshore, forming a breakwater about 9,000 metres long.

The caissons required a total of 600,000 tons of concrete and 3,100 tons of steel to build, and the construction time was only half a year, almost exceeding the capacity of British industry after four years of war, but Britain did everything in its power to complete the project, with 500 officers, 1,000 soldiers, more than 20,000 workers and many shipbuilding units involved.

Of the 146 caissons, 57 were built in the only eight dry docks, 41 were built on floating docks and slipways, and the remaining 41 were nowhere to be built, and in a hurry, Tennant dug 12 deep pits near the River Thames, then built the foundation of the caissons in the pits, and then filled the pits with water to complete the rest of the construction in a floating state.

Secondly, 23 straight piers were built for the vehicles on the landing ships to sail directly to the beach, which were connected by steel tanks with a displacement of 5,000 tons 61 meters long, 17 meters wide and 18.4 meters high, fixed on piles driven to the bottom of the sea, which could rise and fall with the waves.

Finally, considering the strong winds and waves in the English Channel in September, it was decided to sink 3 old warships and 56 old merchant ships outside the concrete caisson breakwater, and moored a number of 61-meter-long cross-shaped steel components about half a nautical mile outside the wreck, and fixed them in two columns with anchors to the 18-meter isobath to form a breakwater about 7,000 meters long.

In this way, the artificial port composed of caissons, straight wharves, wrecks and cross steel components, with an area of about five square kilometers, is a relatively complete wave-proof water, which can berth 7 large ships with a draft of 10 meters, 20 offshore transport ships, 400 tugboats and 1,000 small boats at the same time, and is expected to have a daily cargo throughput of 12,000 tons.

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[Special thanks to; I asked the laborer to reward 10,000 starting coins] (to be continued.) )