In Europe, after losing sea supremacy, the British continued to resist. Because Britain concentrated all its manpower and material resources on aircraft manufacturing, and with the full support of the United States, its air force was equipped with an unprecedented number of more than 12,000 fighters. As a result, Germany and Austria were unable to seize air supremacy within the British Isles, and the naval fleet had to avoid the range of British Air Force fighters and carry out ocean-going blockade missions 250 nautical miles away from the British coast.

The large convoy that Britain had before the war was no longer useful, but most of it was stranded in North America, and most of it was now sent to the Pacific.

You have a good plan, I have a wall ladder.

Britain's surface transportation channels were cut off, but the United States and Britain were forced to speed up the process of developing transport submarines. In fact, after the outbreak of the war, the British Navy, after assessing the strength of the Royal Navy and the German Navy, came to a rather pessimistic conclusion. In order to prevent "accidents," the development of a large transport submarine was carried out using the design scheme of the "submarine carrier" obtained from the Japanese Navy.

At the beginning of 1940, the British built the first W-class transport submarine "Liberty Wheel", which had a surface displacement of 3,100 tons, much larger than the submarines in service in various countries, and an underwater displacement of an astonishing 6,150 tons. Since it was developed as a special transport submarine, the "Liberty Wheel" was equipped with only two bow torpedo tubes as a weapon for self-defense, and was also equipped with a 105-mm deck gun, two quadruple Bofors 40-mm anti-aircraft guns, and two twin 20-mm Erikon anti-aircraft guns on the deck.

The Liberty Wheel is powered by two Vickers diesel engines and two electric motors, with twin-shaft and twin propeller propulsion, with a power of 6,500 hp/2,400 hp, a speed of 17.2 knots (surface)/7.5 knots (underwater), and a cruising range of 16,700 nautical miles. It can transport more than 800 tons of goods at a time.

The design of the British W-class submarines was quite successful, before the Battle of the Atlantic. The first batch of 10 W-class submarines were built to and from the United Kingdom to the coast of North America. And because it was equipped with a radar and sonar system with excellent performance, it was able to avoid the interception of the German-Austrian surface attack fleet and submarines from afar, and none of them were sunk.

Due to the cutting off of surface transport, the shipbuilding industry in Great Britain began to build such specialized transport submarines in full force, and the British supplied the technology to the United States free of charge. With the support of the huge shipbuilding industry in the United States, more and more "Libertywheel" submarines were built and equipped into the submarine forces of Britain and the United States.

The Americans simply canceled the torpedo tubes and 105-mm deck guns on the W-class submarines, and only installed anti-aircraft guns that were common to the navy, and because of the standardized design and sectional construction process, the speed at which the American shipyards built the W-class submarines was much higher than the speed at which they built submarines in the past, and after the initial adjustment period, the Americans have even shortened the construction period of the "Libertywheel" class transport submarines to three months.

As a result of the commissioning of a large number of "Libertywheel" class submarines, the supply of important strategic goods to Britain was restored. This allowed the British to continue their stubborn resistance.

In this regard, the German and Austrian Admiralty was also strange at first, initially believing that its own naval blockade line had a large hole, but after increasing the number of aircraft carrier patrols, the situation still did not change. The initial German-Austrian strategy of using the material blockade to force Britain to surrender failed.

After several months of attrition in the air battle of Britain, Germany and Austria were the first to be unable to accept the loss of a large number of excellent pilots, and after losing more than 7,000 combat aircraft and more than 10,000 pilots, Germany and Austria reduced the frequency of bombing the British islands. The loss of fighters was not intolerable. But because it was a battle over the British, the loss of pilots could not be replaced. In fact, the percentage of pilots killed in air combat is not very high. It was about 15 percent of the number of downed planes, but even if the German-Austrian pilots managed to parachute or make a forced landing on land or sea, they could only become prisoners of the British.

The "Spitfire" fighter equipped by the British Air Force and the improved BF109G fighter and the Austro-Hungarian SM38F "Saker" equipped by the German are all among the world's top propeller aircraft, and their performance is almost the same. Since it was a battle over the British mainland, the losses were greater on the German-Austrian side, of course. It was the bomber crew that lost more of the losses.

The German-Austrian side urgently needed to develop a more powerful bomber.

With the defeat of the months-long Battle of Britain, the British battlefield fell to peace. The German-Austrian intelligence agencies were still informed of the W-class submarine, and the surface ship force also captured a W-class transport submarine that had surfaced on the surface due to a malfunction.

But at present, there are no good countermeasures, it is difficult for surface ship forces to catch their traces, and German-Austrian attack submarines have no way to take them. At present, torpedoes can be launched at a maximum depth of only 35 meters, while the maximum depth of the W class is 120 meters. After increasing the anti-submarine capabilities, Germany and Austria also sank only 18 W-class submarines in March, and after suffering losses, the British and American navies also began to send attack submarines to escort the transport submarine formation.

There have been no major battles in the North Atlantic, and the Americans have been stepping up to improve their naval strength, avoiding surface battles with the German-Austrian fleet. But underwater, the dark tide surged, and it became extremely dangerous, and both the Anglo-American alliance and the Axis powers sent a large number of submarines, and from time to time a large-scale submarine battle would break out.

On the Eastern Front, the Caucasian Army, with the support of the Austro-Hungarian army, consolidated the line and began a counteroffensive in some areas, but in the Donets-Don republic, the Soviets launched a large-scale "spring offensive", and the Soviets, having captured Elista in Kalmykia, entered the Kuban region.

In order to ensure the safety of the Maikop oil field, which was vital to Germany, the German General Staff ordered the formation of Army Group South, with Field Marshal Bock as the commander-in-chief of the group of army groups, under the jurisdiction of the German Second, Sixth, Eleventh and Seventeenth Armies, and the First and Fourth Panzer Armies, with a total strength of 570,000 troops. The Austro-Hungarian side also strengthened the strength of the Don Front, with Archduke Eugen as commander of the Don Front and General Gianni as chief of staff of the Don Front, under the jurisdiction of the Austro-Hungarian Second and Fourth Armies and the Second Panzer Army, with a total strength of 400,000. In addition, the Italian side sent an expeditionary force consisting of three infantry divisions and one armored division of the Italian Eighth Army.

Zhuashvili was extremely dissatisfied with the progress of the Soviet army, and before the arrival of spring, the Soviet army mobilized 2.2 million men to form the Southwestern Front, which was ready to conquer the entire Donets-Don Republic in one fell swoop, and wipe out the opponent's remaining 550,000 Cossack corps. After learning of the large-scale movement of Soviet troops, the German-Austrian side also began to step up the dispatch of reinforcements to the Don region.

A big war is on the verge of breaking out. (To be continued......) R1292