The locomotives employ a Siemens Sibas 32 control system, along with an electrical transmission system from the same manufacturer. It takes advantage of water-cooled gate turn-off thyristor (GTO) semiconductor technology for pulse-width modulation inverters to supply power to the alternating current traction motors, located on a nose-suspended drive. The auxiliary electrical equipment was powered by an insulated-gate bipolar transistor (IGBT) inverter. NSB's Di 3, Di 4, Di 6 and Di 8 can all be run with together with up to three locomotives in multiple. The class is characterized by motormen as a comfortable locomotive with a good working environment. Due to their loading gauge, the Di 8s cannot be used on the British mainline railways, and are limited to being used on the internal steelworks railways.