C5/2003R Last car of freight train displaying bearing damage and derailing in Lahti on 28 May, 2003
On Wednesday May 28, 2003, at 23.42 hrs, the last car of a freight train derailed at Lahti station. The freight train was travelling from Joutseno via Riihimäki toward Tampere. As a result of the incident, the last car of the train, three turnouts, an electric-railway pole with its foundation, and about one kilometer of track were damaged. The overall costs generated by the incident amounted to about € 220,000.
As the freight train was approaching Lahti station, an axle of its last car broke and the car derailed. A remote control operator working at Lahti station heard the sound of a car wheel beating the sleepers, and he perceived a jet of sparks protruding from beneath the car, when the car was arriving at the station. By using his line radio, he told the engine driver to stop the train.
The breaking of the axle was caused by a sticking of the wheel bearings. In fact the brass holder of the outer bearing had probably broken and thereby caused the damaging and sticking of the outer bearing. Thereafter also the inner bearing had stuck. The bearings having stuck, the axle heated and was glowing red and finally it broke. Then the axle box came loose and flew off by the track. As a result, the wheelset derailed.
As all bearings of the type referred will be taken out of service, the Accident Investigation Board of Finland does not give any relevant recommendations.
In terms of hot-box detectors, the Accident Investigation Board notes a favourable development and progress and suggests that their generalization take place at an even faster pace than currently.