This principle, mainly devised by the german branch of swiss-based Brown, Boveri & Cie lay the foundation for all current electric and diesel-electric rail engines.

In Norway, a new four-axle Locomotive, Mark El-17, was launched during 1983 with top speeds up to 93 miles per hour (150 km/h).

While the electric equipment exceeded expectations, the mechanical part suffered from its lightweight construction necessitated by the heavy electronics of the time.

Original plans to build up to 2,000 machines were ultimately ended by DB's privatisation.

The 120s went to DB Fernverkehr, the other divisions of Deutsche Bahn ordered locomotives that featured technologies from the 120, but were not direct successors.