The E 50 was developed from 1950 as a heavy freight locomotive to have a modern successor to the E 94. A lot of experience from the development and operation of the E 94 was brought in, but it was created as a standard electric locomotive together with the E 10 and used the same modern components and production methods.

To ensure sufficient traction and tractive power, the locomotive was designed with six axles. This means that the power per traction motor could also be slightly lower compared to the E 10 in order to achieve cheaper production and a longer service life. Since there was not much confidence in the new power transmission via rubber ring springs for heavy freight train use at the beginning of production, the motors in the first 25 locomotives built were designed with nose-suspended motors and the new technology was only used for the later ones. It is not surprising that the early examples didn't fare any worse when one considers that most locomotives up to 160 km/h are now being built with nose-suspended motors. In order to prevent the front bogie from lifting when starting off with a heavy train, the bogies were connected with a cross coupler. In order to reduce wear on the rails, however, this coupling was no longer used in the last batch and instead replaced by adjustments to the bogies themselves.

Production ended in 1973 after 194 locomotives, after the locomotive now known as class 150 had a successor in the form of the 151. It proved to be a reliable workhorse, even if reduced power in the upper speed range became apparent over time due to the simplified traction motors compared to the E 10. The more powerful and faster 151 was initially only able to compete for part of its missions, until it was increasingly pushed out of line service by the modern 152. In the end it was only used for pushing on ramps and for shunting and was retired in 2003. Lacking the prestige of an express locomotive, all but two were scrapped within a short period of time.