ABSTRACT

Vehicle vibrations at the newly opened Hallandsås tunnel in southern Sweden caused a temporary speed restriction and a massive media attention. The problem was solved efficiently by Trafikverket, the infrastructure manager, and SJ, the rolling stock operator, working together. The cause of the vibrations was bogie hunting, caused by high equivalent conicity. An improved wheel reprofiling programme, together with corrective rail grinding has eliminated the vibration problem by the tunnel, and the temporary speed restriction was lifted shortly afterwards. The successful project has trigged a collaboration between Trafikverket and SJ to improve the detection and mitigation of poor ride comfort.