Class Rm electric locomotives are a set of two units for the Swedish State Railway (SJ), designed based on Class Rc4 and specifically built in the 1970s as replacements for the Class Dm3 locomotives. A total of six units, numbered Rm 1257 - 1262, were constructed for ore transport along the Kiruna - Narvik line. These locomotives feature a higher weight, different transmission, and a lower top speed of 100 km/h, compared to the Dm3's 135 km/h. Initially utilized in triple traction configurations Rm+Rm+Rm, their deployment later shifted to a combination of Rm+Rc4+Rm. Despite their innovative design, the Rm locomotives did not achieve the anticipated operational success, leading to the continued use of the Dm3 locomotives for ore trains, while Rm units were repurposed for individual service in regular freight operations.

Key features include a prototypical front with an automatic coupling replica, fully equipped locomotives, and digital mode capabilities for switchable high beam and individually controlled headlight or tail light.