Stadtbahnwagen M/N

The Stadtbahnwagen Typ M/N (translation Type "M/N" Light Rail Vehicle) is a light rail vehicle used by several Stadtbahn and tram networks in Germany and Austria plus second hand in Poland, Romania and Turkey. It was mainly developed by Düsseldorf-based Duewag, who also built most of the vehicles. As the type evolved over two decades of production, some vehicles have little more in common than their outer dimensions and the basic configuration of a two or thee-part vehicle on three or four bogies with both outer ones powered.

History
Development started when the transport authorities from Bochum, Essen and Mülheim asked Duewag to develop a standardised vehicle for their meter gauge tram networks, soon followed by Bielefeld and Krefeld. Initially the tramcar was designated Stadtbahnwagen R (R = Ruhr), but the definitve name became Stadtbahn M (M = Meterspur (meter gauge)). In 1976 the Stadtbahn N (N = Normalpur (standard gauge)) for Dortmund was introduced.

Subtypes
Different variants are usually referred to by a combination of their gauge, number of axles and a letter denoting the engine type.