The German companies Ingenieur Kontor Lübeck (IKL) and Howaldtswerke-Deutsche Werft (HDW) collaborated to offer an enlarged version of the Type 209 submarine, designated the Type 2000 [REF].
The Dutch partnership of United Shipbuilder Bureaux and Rotterdamsche Droogdok Maatschappij submitted the Walrus class [REF].