For the transportation of heavy freight trains on main lines in flatlands, BZA Munich, Kraus-Maffei, and SSW developed the BR E 40, which was largely similar in technical design to the E 10.1. Only the gear ratio was changed, and the standard installation of an electric brake was omitted. Over 800 units of the 110 km/h machines were put into service starting in 1957. Their power output was 3,260 kW. In 1968, they were reclassified as BR 140. For a long time, they bore the main load of freight traffic on electrified routes but were also used for passenger trains. At the end of 2016, after nearly 60 years of service with DB, they were retired.