supplied a design modified from the , but the submission review board did not view this favourably, as the submarine was of the same vintage as the Oberons. Their submission was altered to a conventionally powered version of the Rubis-class nuclear submarine. 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. Submarines based on the Type 209 design had been exported to several nations, but were not operated by the German Navy. Thyssen Nordseewerke, another German company, offered their . Like the Type 209, the TR-1700 was an export-only submarine design. Cantieri Navali Riuniti of Italy proposed a design based on their , scaled up by 25%. The age of the early 1970s design was a concern, and the proposal was withdrawn early in the process. The Dutch partnership of United Shipbuilder Bureaux and Rotterdamsche Droogdok Maatschappij submitted the . Their offer was identical to that constructed for the Royal Netherlands Navy, minus the Dutch combat system. Swedish shipbuilder Kockums submitted the Type 471 design, an enlarged version of the operated by the Swedish Navy. The United Kingdom company Vickers Shipbuilding & Engineering offered a design referred to as the Type 2400, that later became the Upholder class. The review board concluded that the IKL/HDW Type 2000 was the best design offered, the Walrus class was rated as 'fair', while Kockums' and Vickers' proposals were considered 'marginal' contenders. However, none of the tenders completely matched the desired RAN specifications, and the two proposals selected would have to be redesigned during the funded study. The combat data system was procured separately to the submarine design; 14 companies were identified as capable of providing what the RAN wanted, from which eight were approached in January 1983 with a separate request for tender. Five responded: a consortium led by Rockwell International of the United States, Plessey of the United Kingdom, Signaal of the Netherlands, Sintra Alcatel of France, and a collaboration between the German Krupp Atlas Elektronik and the British Ferranti. Each tender was required to offer a system with a distributed architecture, despite the absence of an accepted definition for 'distributed computing' at that time, and had to show the cost of programming the software in Ada, although they could offer additional cost breakdowns for other programming languages. Funded studies By May 1985, three months