The Type IX U-boats were German ocean-going submarines whose construction was initiated in 1938. Depending on the subtype, the Type IX units were 76.5 m to 87.6 m long, 6.5 m to 7.5 m wide, and their underwater displacement ranged from 1,150 tons to 1,800 tons. The maximum surface speed of Type IX U-boats ranged from 18 knots to 21 knots, and the maximum underwater speed was approximately 7 knots. The main armament was 6 533 mm torpedo tubes: 4 bow and 2 stern, with a total of 22-27 torpedoes carried on board the ship. The secondary armament consists of 1 105mm cannon, or 1 105mm cannon, 1 20mm AA cannon, and 1 37mm cannon in the IX B, IX D-1 and IX D-2 subtypes.
The Type IX U-boats were created as a development and a significantly improved version of the Type I A U-boats. Their swimming range, artillery and torpedo armament have been significantly increased. Several subtypes of this class of ships were created in the course of serial production. Chronologically, the first was the Type IX. Later, the Type IX B was created, with a slightly increased range and reinforced anti-aircraft armament. Another type was the Type IX C and C-40, which were larger than their previous ones and their maximum operating range was again increased - to almost 25,000 km. Finally, the last variants were the subtypes IX D-1 and IX D-2, in which the maximum speed was increased to 21 knots on the surface and the torpedo reserve. During World War II, ships of this type operated primarily in the Atlantic, against Allied merchant shipping, but also they went to the Indian Ocean.
HMS Vanity (D28, later L38) was a British destroyer from the period of: World War I, the interwar period and World War II. The keel for this unit was laid in 1917, the launch took place in May 1918, and the entry into service took place in June of the same year. The total length of the ship at the time of launching was 95 meters and a width of 8.2 meters. The displacement reached approximately 1,300 tons, and the maximum speed was approximately 34 knots. The armament at the time of the launch consisted of, among others, four 102 mm guns or two 40 mm guns.
HMS Vanity was one of the Type V destroyers. The ships of this type were designed with the best performance and relatively strong artillery armament. They also focused on new technological solutions used on other British destroyers of the First World War and the period preceding it. Undoubtedly, when they entered service - from 1917 - they were modern and successful destroyers, but with time their combat value decreased. HMS Vanity took part in the last months of World War I and in the activities of the Entente in the Baltic related to the Russian civil war. However, in the 1930s he was sent to the reserve. He returned to active service in 1939 - with the outbreak of the next world war. However, the return was preceded by modernization and change of weapons. During World War II, the ship served primarily as an escort unit, and in 1940 its anti-aircraft armament was strengthened. In the years 1939-1940 it protected convoys sailing in the North Sea, and in 1943 it operated in the English Channel. Interestingly, he did not take part in the Allied landing operation in Normandy in June 1944. HMS Vanity was decommissioned in 1946 and sold for scrap metal shortly thereafter.