The abundance of water power from the mountains led very early to the development of electric locomotives in Bavaria. In order to fulfill the increasing demands in heavy passenger service, Maffei produced several designs for the Management Group Bavaria in a contract with the German State Railroad. The final result was a locomotive with four motors, two each driving two powered axles by means of a jackshaft. This allowed these locomotives with their own weight of 140 metric tons to reach a maximum speed of 90 km/h or 56 mph. These locomotives were initially designated as the class EP 5 and were later taken over by the DRG as the class E 52. A total of 29 of the original 35 units reached the German Federal Railroad, but they were retired in the Mid-Seventies.