Locomotive set with two Rm electric locomotives of the Swedish State Railway. Form variation! ¦ Design in original condition ¦ Prototypical front with replica of the automatic coupling ¦ Both locomotives fully equipped ¦ Switchable headlight with DIP switch As a replacement for the three-part electric locomotives with rod drive of the class Dm3, six Rm 1257 - 1262 units based on the Rc4 were built in the 1970s for ore transport on the Kiruna - Narvik line, with a higher weight, different transmission and lower top speed (only 100 instead of 135 km/h). Initially, the units were used in triple traction Rm+Rm+Rm; later the composition was changed to Rm+Rc4+Rm. However, their expected success did not materialise as desired, meaning that the tried and tested Dm3s continued to pull the ore trains and the Rms, after several conversions, were used as individual units in regular freight train service.