Laroche-Migennes english summary
At 08:02 on 1 December 2015 in the station at Laroche-Migennes located in the municipality of Migennes in the Yonne, regional express train No. 891 350 travelling between Dijon and Auxerre-Saint-Gervais derailed at a speed of 20 km/h at switch points Tb on track A.
The direct cause of the accident was the fact that an earlier train had trailed through and damaged the Tb switch points.
In fact the switch points had not been put back into their proper position after a maintenance machine passed through them at around 04:00 to stop in a siding at Point R. In order to carry out this manoeuvre, the driver had used a safety key on the basis of an authorisation given by the signalman at Position 4 at Laroche-Migennes which controls these switch points remotely. On conclusion of this manoeuvre, the driver forgot to put the switch points and the key back to their proper position and to return the authorisation to the signalman.
An engineer intervened to restore the authorisation using an emergency key but without checking the position of the switch points.
At 06:30 the lug end of a first train crossed the wrongly positioned switch points ; the points were damaged by the passage of the wheels, forcing the switch point rail half open.
An hour and a half later, regional express train No. 891 350 approached to cross the switch points by the point rail and derailed.
Two factors contributed to this situation :
- the official procedure for using an emergency key which does not give any information to the signalman about exactly which machines are being manoeuvred and which manoeuvres are being carried out by the person requesting the key, especially as the safety installation includes switch points and crossings which are not remotely controlled by the signal box ;
- intervention by numerous personnel external to the Laroche-Migennes site in the safety procedures and the lack of formality and implementing the procedures.
In view of these factors, BEA-TT sent two recommendations to SNCF Réseau concerning the following aspects :
- procedures for using the Point R safety installations, particularly when the emergency key is used ;
- the roles and assignments of the permanent operational managers on a regional and national level.