Dm and Dm3 is a series of locomotives used by Swedish State Railways (Swedish: Statens Järnvägar, SJ) and later Malmtafik i Kiruna (MTAS) for pulling iron ore trains on the Iron Ore Line in Sweden and Ofoten Line in Norway. A total of 39 double-locomotives (Dm) were delivered between 1954 and 1971, built by ASEA. A further 19 center locomotives (Dm3) were later delivered. Norwegian State Railways also operated 12 similar locomotives, designated NSB El 12. The Dm is a articulated, freight-optimized version of the Da-locomotive.