The first section of the Bergen Line, the Gjøvik Line and the Roa–Hønefoss Line, was electrified in February 1961. This allowed diesel and electric locomotives to haul all trains from Oslo to Bergen. In 1962 the Nordland Line was completed to Bodø, but the increased need for locomotives was more than compensated by the electrification of the Bergen Line being extended to Ål. The first Di 3 ran on the Røros Line in 1964, that had previously been denied due to bridges with insufficient axle load permits. In 1965, the Bergen Line was electrified, and all but one Di 3 was transferred to Trondheim. A single unit, usually no. 610, was stationed at Finse Station as a snowplow. Along with additional deliveries, there were sufficient Di 3 units to terminate most steam operations.