Sp.2 and Sp.3 respectively. Two ships (Z.44 and Z.45) were never completed, being suspended in 1944 and scuttled incomplete after the war. The three that were commissioned were all lost. Zerstörer 1936C Five ships of this class were ordered in 1942 and 1943 (Z.46 – Z.50), all from A.G. Weser at Bremen; none were launched, just two were started – Z.46 and Z.47 – and both were bombed by Allied aircraft while under construction and were scrapped on the slipways in 1945. This design was a response to the vulnerability to air attack of early German destroyers and would have used six new 128 mm Flak 40 guns (originally designed for the Luftwaffe) as dual purpose weapons in twin mountings. The number of smaller calibre anti-aircraft guns would have also been increased. Zerstörer 1938A/Ac In order to provide support for larger German warships operating far from their bases, the development of large ocean-going destroyers started in the late 1930s. They would have had dual power systems to enable long endurance cruises. Twenty-four of these were planned under Plan Z but were not actually ordered – the concept was developed further into the Spähkreuzer (see Type 1936B above). Zerstörer 1938B Ships of this class would have been small destroyers designed to patrol and operate in Baltic and coastal waters, but would have had quite big operational range for such purpose, and could have also been used in high seas. Twelve ships were ordered in the summer of 1939, but after the start of World War II, all were cancelled. Zerstörer 1942 Experimental testbed destroyer powered by diesel engines for long-range operations. Based on design of unbuilt Type 1938B destroyer, with six diesels driving three shafts, with an estimated speed of and an operating radius of . One ship, Z51, was laid down in 1943 and launched in 1944, but was sunk by Allied bombers on 21 March 1945 while fitting out. Zerstörer 1944 While Z.51 was a testbed for diesel propulsion, the Type 1944 destroyer was a production class of large, diesel powered destroyers. They were planned to have a revised armament, with six 128 mm Flak 40 dual purpose main guns, and an all-new anti-aircraft armament, with three 5.5 cm Gerät 58 intermediate calibre anti-aircraft guns and a close-in armament of 14 30 mm guns in seven twin mounts, with eight torpedo tubes. Five of these ships (Z.52–Z.56) were ordered