On 4 March 1966, in a merger with Koninklijke Maatschappij De Schelde and Motorenfabriek Thomassen led to the creation of Rijn-Schelde Machinefabrieken en Scheepswerven (RSMS), and a further merger on 1 January 1971 with Verolme Verenigde Scheepswerven (VVS) led to the united company of Rijn-Schelde-Verolme Machinefabrieken en Scheepswerven (RSV).
On 6 April 1983 the bankruptcy concerning RSV and RDM were pronounced. The offshore department was closed and the repair department transferred to Wilton-Fijenoord, by means of sale of the two largest docks. Of the 3,180 employees, 1,370 people became unemployed. The still viable components, the naval and the tool and heavy machinery businesses, were categorised in a new company: RDM Nederland BV, property of the government.
Navy construction got a large boost by the orders for Walrus class submarines for the Royal Netherlands Navy. However, proposed supply of submarines to Taiwan failed to materialize, in part due to political implications. However, as ship building orders declined, and the company became more involved in high technology systems development for the military and energy sectors, the name of the company was again changed, this time to RDM Technology.
On 20 December 1991, the company was sold by the government to the Royal Begemann Group of Joep van den Nieuwenhuyzen, and renamed RDM Technology Holding BV. Due to a lack of orders, employment was cut from nearly 1,200 to under 500 during reorganizations in 1993 and 1994, while the the departments were divided into RDM Technology BV and RDM Submarines BV.
In 1996, these companies were privately obtained by van der Nieuwenhuyzen. They were used for several activities and financial operations in the weapons industry, but no longer in association with the company's original shipbuilding activities. The shipyard itself was eventually acquired by the city of Rotterdam.
The primary business of RDM had always been ship repair in its drydock facility, although it also built several new vessels over the years. The company also became a strong competitor in building equipment for offshore drilling by the mid 1960s.
Ships built by RDM include: