Rotterdamsche Droogdok Maatschappij

The Rotterdamsche Droogdok Maatschappij (RDM) was a major Dutch shipbuilding and ship repair company in Rotterdam that existed from 1902 to 1996. Over its life it built 355 ships, 18 of them submarines, operated twelve floating docks and employed up to 7,000 people. It grew out of the older yard De Maas, founded in Delfshaven in 1856 by Duncan Christie. A consortium of Rotterdam harbour interests led by A.G. Kröller of the Müller shipping line prepared the takeover in 1899, the company contract was signed on 23 January 1902 with a capital of one million guilders, and its new shipyard at Heijplaat opened on 3 October 1903 with two floating drydocks built in Scotland. A submarine hall followed in 1928 and 1929, and later naval work included Walrus-class submarines for the Royal Netherlands Navy. In 1966 RDM merged with De Schelde and Thomassen to form Rijn-Schelde, and in 1971 the group merged again into Rijn-Schelde-Verolme, whose bankruptcy, with RDM, was announced on 6 April 1983.