C4/1999R Hot-box detected in passenger train at Viinijärvi, on 5 March, 1999
A hazardous situation in rail traffic arose at Viinijärvi station when a hot-box was detected in a passenger train. As a result the bearing was damaged. The M831 train arriving at Viinijärvi station, the train guard discovered smoke originating from the rear bogie of the first coach. The train guard then detected a hot-box in the right bearing of the last wheelset of the coach. Therefore the coach was detached and left at Viinijärvi. The wheelset was badly damaged and as a consequence it had to be scrapped.
The hot-box was generated as due to major material-fatigue fractures in the rim surface of the wheelset. These fractures were the outcome of great number of kilometres the wheelset had been in use. In fact the uneven wheelrim surface generated a heavy vertical stress in the bearings, and hence the bearing was damaged.
A three year maintenance interval is applied for wheelset bearings, allowing for an additional six month maitenance work time. In connection with the bearing maintenance, also the wheelrims are turned. As the preceding wheelset maintenance operation had taken place just three years earlier, there were still six months reserved for the maintenance work. However the wheelset had been in use for great number of kilometres and therefore the wheelrims ought to have been turned earlier.
In view of a prevention of corresponding hazardous situations and incidents, the Accident Investigation Board of Finland recommends that the wheelset maintenance intervals be determined as depending on the kilometre volumes travelled instead of / in addition to the time-bound maintenance intervals. Furthermore Accident Investigation Board reiterates its earlier recommendation for a development of hot-box detection and control and a development of the relevant equipment and devices used.
- Recommendation S85
- Recommendation S139