 The combined track and ferry service was primarily used to transport raw materials and fertilizer from Norsk Hydro's factory at Rjukan to the port in Skien.It was the target of a Norwegian operation on 20 February 1944, when resistance fighters sank the ferry in the deepest part of Lake Tinn in order to prevent Nazi Germany from receiving heavy water.The railway ferries operated a route connecting the Tinnoset Line and Rjukan Line.