The Type XXI U-boats were German ocean-going submarines that started serial production in 1944. The Type XXI units were 76.7 m long, 6.6 m wide, and had an underwater displacement of 1,820 tons. The maximum surface speed of the Type XXI U-boats was 15.6 knots, and the maximum underwater speed was 17.2 knots! The main armament of the Type XXI units were six 533 mm torpedo tubes located in the bow. Secondary armament is 2 twin 20mm AA cannons or 2 twin 30mm AA cannons.
The Type XXI U-boats were created in connection with the increasing losses incurred by German submarines in the Battle of the Atlantic, related to the use of more and more sophisticated methods by the Western Allies (Combating Submarines). The Kriegsmarine command in 1943 decided to create a completely new type of submarine, which turned out to be a technological breakthrough in the construction of this type of units. First of all, a large-scale modular structure was used in it, which significantly reduced the production time of a single ship. In addition, a new type of propulsion was used and a much better hydrodynamic shape of the hull and kiosk was taken care of, which allowed for the phenomenal underwater speed of 17 knots for those times! The Type XXI ships also had a long range, a very large maximum depth, and were much quieter than previous German submarines. They also had rich - as for the end of World War II - electronic equipment. All these qualities made them an extremely dangerous weapon against Allied merchant shipping in the Atlantic. However, considerable delays in production, the offensive bombing of the Western Allies over Germany and the loss of the Atlantic ports in 1944 meant that the first Type XXI ships did not enter operational service until March 1945! However, after the end of World War II, the acquired copies were intensively researched by the Americans, the British and the Russians and, to a large extent, marked the development of submarines in these countries until the end of the 1950s!