In order to be able to haul express trains also in curves at the same speed as railcars, the SBB ordered an electric locomotive with an axle load of only 14 tonnes. With the light steel wagons it was possible to reach the required speeds even with a light locomotive. A total of 50 locomotives were built in two batches. The first batch had an electric brake and partly multiple controls, the second batch didn't have either. They were initially called Re 4/4 and only renamed with the introduction of the Re 4/4II. Some of them were used until 1998, at last in regional traffic and for shunting. 