F-class escort ship
The F-class escort ships were a multi-purpose class of 10 fleet escorts () built for the German Navy (Kriegsmarine) in the 1930s. During the Second World War, their unsatisfactory reliability and poor seakeeping abilities had them soon relegated to second-line duties in the Baltic Sea. Four ships were sunk during the war and the survivors were scrapped afterwards. Construction The ships were built by Germaniawerft (F 1 – F 6), Kiel, Blohm & Voss (F 7, F 8) and Wilhelmshaven dockyard (F 9, F 10). They entered service between 1936 and 1939. Similar in size to the Type 35 and Type 37 torpedo-boats, the ships were originally conceived as fast fleet or convoy escort ships that could also perform anti-submarine and minesweeping work. They were also used as a test bed class for a new high-pressure steam power plant intended for use in destroyers. As a class, they were overloaded and over-engined, which contributed to severe hull stress and very poor sea-keeping characteristics; these flaws were partially remedied by extensive rebuilds between 1938 and 1940. The power plants likewise proved to be prone to frequent breakdowns, and most of the ships were removed from operational service during the later years