C9/2001R Locomotive Wheelset Derailing on Riihimäki Railway Yard on 31 July, 2001
On 31 July, 2001, a wheelset of a locomotive derailed on Riihimäki railway yard in Finland. The incident took place in connection with the transfer of the arriving train to a holding track. As a result of the incident, the traction motor, cardan shaft, axle drive, brake leverage and wheelset of the locomotive were damaged. Also track and turnout fixing parts suffered some damage.
The incident was caused by a loosening of the screws that fixed the rod-locking disc in the lower part of the axle-drive suspension, and the ensuing falling off of the rod. The folding base plate under the screws had failed to be secured by its turning against the screw heads. It is moreover possible that the screws had failed to be tightened in connection with a wheelset replacement operation carried out in the locomotive on 16 March, 2001.
As a consequence of the incident, all axle-drive suspensions in the Sr1 locomotives were checked. The Accident Investigation Board of Finland does not wish to formulate any new relevant recommendations.