Stellwerk Köln-Dünnwald

The building stands at the former Köln-Dünnwald depot along the Mülheim-Speldorf–Troisdorf railway line. The station was originally served from both ends and controlled by two mechanical standard-design signal boxes. In 1970, a DrS2 route-relay interlocking was installed in the Köln-Kalk-facing box, which later served solely to protect level crossings. The signal box was decommissioned in 2010 after the level crossings were upgraded to centrally controlled block signals operated from Köln-Kalk. Museum construction began in the building the following year.

The star of the collection is the surviving DrS2 push-button interlocking. Its original relay assembly is displayed behind glass in a purpose-built section of the operating room, giving visitors a clear view of the inner workings. A second installation has been fully restored to working order: a SIMIS B electronic interlocking from 1991 — one of the earliest of its kind on the German rail network. It originally operated at Essen-Kupferdreh station, where it was taken out of service as early as 2003; Deutsche Bahn retired all SIMIS B units network-wide by the end of 2016 due to their age.

A further section of the museum explores internal railway communications. The complete telephone exchange from a signal box — including the query and switching equipment — has been fully reconstructed. An operations simulator allows visitors to experience rail traffic management from a variety of perspectives.