C1/1999R Passenger coach derailing at Mynttilä, on January 30, 1999
On Saturday 30 January 1999, the first coach of a passenger train derailed at Mynttilä. The derailment occurred on a turnout when the train started to reverse. In the accident the point of the turnout broke and the underframe of the coach suffered some damage. As a result of the derailment, the train was running about 2.5 hours late.
In reverse pushing, the wheels of the coach bogie closest to the locomotive were guided to the wrong track, whereas the wheels of the locomotive took the right-hand side of the point and then the right-hand side track. The locomotive continuing its pushing, the bogie of the coach having taken the wrong track derailed and made the bogie travelling on the right-hand side track, derail as well.
The turning of the double diamond crossing under the train was presumably caused by an erroneous pressing of the button of the turnout in question simultaneously with the turning of the turnout of the main track by means of local points operating buttons. The error made in the buttons was due to the illogical order of the buttons (see Figures 3, 4 and 5). Actually when giving a reversing permission to the train on the turnout, the remote-control operator failed to perceive that the turnout was off control.
In order to avoid such derailments in the future, the Accident Investigation Board of Finland recommends that when turning turnouts by means of local points operating buttons, the train should remain at the signal protecting the turnout referred to, or in any case it should be off the turnout. The Accident Investigation Board of Finland recommends that local points operating buttons be located in a logical order in relation to the location of the turnouts to be turned.