A series of 15 strengthened and heavy locomotives was built in 1961. Unfortunatelly at this moment there have been no suitable ore wagons, so the machines were delivered as duplex-locomotives. The middle sections had been ordered in 1966, because it was foreseeable, that in 1967 suitable ore wagons for 5.000to trains were available. The whole length of this locomotive represents 35.250mm, so the Dm3 belong to the longest electro locomotives in the world. Striking on this locomotive are the SAB-wheels with the rubber band jacket spring of the wheel rim and the rod drive.
- SJ origin big lamps, brown
- SJ modernized small lamps, brown
- LKAB small lamps, blue/grey