The City-Bahn (CB) was a German train category introduced by the Deutsche Bundesbahn (DB) in 1984 for local train services, in order to make secondary routes more attractive. Old Silberling coaches were modernised and a more frequent fixed-interval service (Taktfahrplan) introduced. As its use spread the DB changed the way it was written to CityBahn. The City-Bahn was replaced by the Stadt-Express.
One of the services was the Cologne–Overath–Gummersbach line, which was opened in 1984 as the Aggertaler on the Agger Valley Railway (Aggertalbahn, KBS 459). For experimental services on the closure-threatened line, Silberling coaches were converted to the then modern interiors of the VT 628.2 and, like the Rhine-Ruhr S-Bahn, painted in orange and light grey livery. A café was also part of the redesign. The trains were hauled by similarly painted locomotives of Class 218. The modernised rolling stock and the fixed hourly services led to a considerable increase in passengers. From 1985 the new City-Bahn rakes ran from Cologne to Gummersbach, and sometimes onwards via Marienheide to Meinerzhagen; however this only lasted until May 1986, then they only went as far as Marienheide, and from May 1987 only to Gummersbach again.
The second City-Bahn route was the Lower Elbe Railway (Niederelbebahn), where trains ran between Hamburg and Stade. Because the line is electrified, Class 141 locomotives were employed.