The increase in the population in the Ruhr and Saal areas led to a demand for fast connections between cities as early as the provincial railroad period. Different studies were commissioned and carried out. The actual breakthrough did not occur until 1932 when the "Ruhr Express Service" was placed into service with a total of 32 trains between Essen and Dortmund. The train routes were continuously expanded and extended to Cologne, Mönchengladbach and Wuppertal-Vohwinkel. In addition to different powered rail cars, the 4-axle "English design" compartment cars turned out particularly well in this service. The attractive paint scheme became a trademark symbol for this regularly scheduled express passenger service. The dense sequence of stations, most of them only a 30 to 60 second stop, demanded locomotives that could accelerate quickly. The class 78 met this equirement as if it were child"s play. The additional sign mounted on the smoke box was another indication of the special use for these units.