Sainte-Pazanne english summary
On 12 October 2015 at 05:40, railcar X 73811 coming from Saint-Gilles-Croix-de-Vie and pulling regional express train no. 859100 derailed across both tracks, at low speed, on switch points 310b located at the entrance of the Sainte-Pazanne station. It stopped 30 metres down with its front bogie on track 2 and the derailed rear bogie on track 1.
The event did not kill any of the 12 passengers or any of the train staff.
The material damage was limited to the running gear of the railcar, the rear bogie of which rolled about thirty metres in the ballast, with trail through of points by the leading bogie, with about thirty metres of track covered by the derailed bogie.
This dual-track derailment follows the transfer of switch points 310b between the two bogies of the railcar.
On the one hand, this event was caused by a 2.7 second disruption on the ITE track circuit in zone 325 and, on the other hand, the Sainte-Pazanne traffic control agent’s recording of an incompatible route with that of the train in question ; this recording was authorised by instruction S6A no. 4 from Infra-Exploitation Pays de Loire.
Trying to find ways to progress has led to the formulation of four recommendations related to the root causes and covering the following topics :
- taking into account the phenomenon of wheels getting clogged ;
- cleaning the rails after track repair operations ;
- the procedures for issuing S6A no. 4 exemptions ;
- the implementation of modern points.
In addition, the investigation showed that the disruption of the CDV ITE track circuits deserved specific monitoring and attention, which led the BEA-TT to formulate a fifth recommendation on this topic.