Originally the main turbines had a production of a total 145 000 horsepower. Later on the turbines were upgraded with new turbine wheels so that the performance increased to 160 000 horsepower at a 250 rotations per minute. Originally each turbine had been installed with fully enclosed, self-ventilating three-phase generators, but in 1929 these were removed and replaced by 2 direct current generators, each with 6 000 kW and 12 000 A. From the restructure until 1971 it was the world’s largest power plant with direct current energy.

In 1913 it was decided that they were to install an 11^th unit. A turbine of the same kind and size as the ones in the main power plant was installed in a reserve-station. This turbine was delivered by Escher-Wyss. In 1925 it was decided to install unit number 12. A vertical Francis-turbine was installed and it provided 17 600 horsepower at 600 rotations per minute. Also this was delivered by Escher-Wyss. This Francis-turbine was the first one in the world that was able to extract water at a fall height as high as 300 meters.

As a visitor you can wander around in the machine hall and experience several of these old turbines up close. In addition you can experience the beautiful architecture that also plays a major role inside the Old Vemork Power Station.