The line was initially operated by steam locomotives, however the cost of steam power was large; and on 7 June 1910 a contract with Allgemeine Elektricitäts-Gesellschaft (today AEG) of Berlin was signed to provide overhead wires and five electric locomotives. The Rjukan Line became the second electrified railway in Norway, after the Thamshavn Line, and the first that would be connected to the main railway network. The first electric locomotive was taken into operation on 30 November 1911. Because only some of the locomotives were delivered, steam locomotive had to help with the service. Because of insufficient safety routines there were several fatalities among employees, and not until 1922 was sufficient policy initiated.