Diether von Roeder or Z17 was a German destroyer, the keel of which was laid in 1936 and launched in August 1937. The destroyer entered the rope service in the German Navy (German Kriegsmarine) in August 1938. The ship was 123 meters long, 11.8 meters wide, and had a full displacement of 3,450 tons. The maximum speed of the Z17 destroyer was 38 knots! The main armament at the time of launch was 5 128 mm guns in five individual mounts, and the secondary armament was: 4 37 mm cannons, 6 20 mm cannons, 8 533 mm torpedo tubes and depth charges.
The Z17 was the first ship of the type named Diether von Roeder. These types of destroyers were a development of the Type 1934 / 1934A destroyers. They had identical artillery and torpedo armament, similar performance, but they significantly improved sea performance and increased boiler house reliability. The result was a series of destroyers with a potential not less than their French or British counterparts. At the outbreak of World War II in Europe, Diether von Roeder was active in the North Sea and in the Danish Straits. At the end of 1939, he participated in the mining of English waters. He took part in the attack on Norway, supporting the German landing at Narvik in April 1940. There, as a result of the difficult situation of the German team and the exhaustion of ammunition, it was blown up by its own crew on April 13, 1940.
Wilhelm Heidkamp or Z21 was a German destroyer, the keel of which was laid in 1937 and launched in August 1938. The destroyer entered the rope service in the German Navy (German Kriegsmarine) in June 1939. The ship was 125 meters long, 11.8 meters wide, and had a full displacement of 3,400 tons. The maximum speed of destroyer Z21 was 38 knots! The main armament at the time of launch was 5 128 mm guns in five individual mounts, and the secondary armament was: 4 37 mm cannons, 6 20 mm cannons, 8 533 mm torpedo tubes and depth charges.
The Z21 was the fifth ship of the type named Diether von Roeder. These types of destroyers were a development of the Type 1934 / 1934A destroyers. They had identical artillery and torpedo armament, similar performance, but they significantly improved sea performance and increased boiler house reliability. The result was a series of destroyers with a potential not less than their French or British counterparts. At the outbreak of World War II in Europe, Wilhelm Heidkamp was active in the North Sea. From October 1939 to February 1940, he participated in the mining of English waters. In April 1940, it took part in the attack on Norway (operation "Weserubung"), supporting the German landing at Narvik. There he was quite successful sinking the Norwegian coastal defense battleship "Eidsvold". As a result of a British torpedo attack, it sank on April 11, 1940.