In 1979 DHR felt more or less compulsive to take over her last Dutch competitor, P.J. van den Bosch. The company kept in production under her original name until 1983. It was then that the lack of space in the mechanical department could be solved. By coincidence a 1000 square meter adjacent lot became available in which the press shop, tool shop and outgoing goods department where housed.
After comprehensive testing by the Royal Dutch Navy the lanterns of DHR were accepted and all governmental vessels were obliged to install our lanterns. After a while DHR designed a navigation light suitable for submarines. Even some foreign governments preferred DHR lanterns for their submarines. In 1984 Marinus den Haan Sr. stopped as a member of the board and became a company advisor for DHR.