Föttinger on the Fottinger hydraulic transmitter known as Vulcan Coupling and Vulcan Drive or fluid coupling. In 1924, Vulcan's Hermann Rieseler invented one of the first automatic transmissions, which had a two-speed planetary gearbox, torque converter, and lockup clutch; it never entered production. (The less-sophisticated Hydra-Matic, which used a simple fluid coupling, was an available option on Oldsmobiles in 1940.) The original coupling further developed in collaboration with Harold Sinclair of Fluidrive Engineering of Isleworth for Daimler of Coventry and matched with a manually controlled epicyclic gearbox went into production in England in 1929. Shutdown In 1928 Vulcan Stettin went bankrupt and sold its Hamburg shipyard in 1930. The AG Vulcan Stettin had been closed. New enterprise 1939 a new company - also named Vulcan - was founded on the site of the former Stettin-shipyard. All together 34 construction numbers were started in the following years, including 18 type-VII C submarines. But because of the war only a few ships could be launched and completed. Among these were two submarines, but only one of them () was ever in service while the second one () was destroyed by allied air attacks before. During the war the yard exploited slave workers and had its own prisoner camp, part of the prisoner population engaged in anti-Nazi resistance, successfully sabotaging several constructed ships After World War II the slave workers were freed and the shipyard was finally taken over by the Polish government and the new Szczecin Shipyard was started at this site. The Szczecin Shipyard named one of its wharfs "Wulkan" and two slipways "Wulkan 1" and "Wulkan Nowa". Ships built by AG Vulcan Stettin (selection) 1851, Constr.No. 1, Paddle steamer Die Dievenow, first built ship 1879, for Shipping Company on the Don, Azov and Black Seas with their tributaries (). After 1886 belonged to Russian Steam Navigation and Trading Company 1880, Corvette Olga 1881–1882, and for Chinese Navy 1887, protected cruiser for Kaiserliche Marine (Imperial German Navy); 1922 broken up 1889, Scandia Hamburg America Line liner, sold to U.S. Army Quartermaster Department 1898 serving as U.S. Army Transport Warren until 1922, sold, burned sunk Shanghai 1924 1891, for Kaiserliche Marine, 1910 sold to the Osman Navy 1892, Aviso and imperial yacht for Kaiser Wilhelm II; 1923 broken up 1897, 4-funnel , won 1898 Blue Riband 1897, Passenger ship Königin Luise for Norddeutscher Lloyd (NDL), 1935 broken up 1897–1899, great cruisers and