In 1937 NSB ordered one pair of diesel-electric locomotives from Krupp in Germany with the engines being delivered from MAN to test. The the outbreak of World War II delayed delivery, and in 1942 only one locomotive arrived in Norway. NSB assigned it the number 1 601.
Probably due to the conditions in German industry at the time, where most of the resources went to the military industry, the locomotive was plagued with faults and was never especially successful. In the 1950s NSB instead ordered the Di 2 and Di 3 units for dieselisation.
1 601 was withdrawn from service and scrapped in 1959.