In 1927, the German State Railroad Company placed a total of 12 units of the class E 91.0 in service. The locomotives" double motors accelerated it to a maximum speed of 55 km/h or about 34 mph. This speed was quite sufficient for the heavy service on steep grades. On these routes, this locomotive was able to put its immense tractive effort to its best use. Six units came onto the roster of the German Federal Railroad, and they were used mainly in the areas of Freiburg and Munich.