EUS - English Summary

On July 24, 2024, at 6:18 a.m., the passenger regional train number 877650, traveling from Villefranche-Vernet-les-Bains-Fuilla to Perpignan, struck a pile of earth that had fallen onto the tracks at a speed of 97 km/h.

The impact occurred at kilometer point (PK) 503.735 on line 679000, in the Têt Valley. Upon impact, the first bogie of the front car derailed, as did the first bogie of the second car. The bogies shifted to the right ; the left-hand wheels, in the direction of travel, remained on the track and were guided by the right-hand outer rail. The right-hand wheels were in the ballast or off the track. The train continued on its trajectory and struck the right abutment of a road bridge located at PK 503.604.
The train came to a stop at kilometer point 503.570. The rear of the train was positioned at the bridge that had been struck. The driver activated the emergency brakes as soon as he saw the obstruction on the track (a pile of dark-colored leaves and mud) approximately 50 meters before the point of impact. The train traveled approximately 240 meters between the emergency braking point and the point where it came to a complete stop.

The accident resulted in one serious injury, the train driver, and four minor injuries, including a train commercial agent and three passengers.
The right-hand pier of the bridge (in the direction of train travel) was damaged, and the bridge was closed to traffic by municipal order. A catenary support was torn down. The rolling stock was heavily damaged, and half of the train was derailed. A 250-meter section of track needed to be rebuilt.

The investigation reveals :

• An immediate cause : The deposit of soil on the track caused the derailment of the regional express train (TER). This soil deposit resulted from a landslide on the adjacent embankment, following an exceptional, one-time influx of water onto the embankment.

• Two main causes of the one-time, one-time influx of water following the opening of a drainage canal hatch by a resident who was draining their meadow :
◦ the unsatisfactory operation of the irrigation system as a whole, with regard to the flow of irrigation water ;
◦ the malfunction of the concrete ditch at the top of the embankment for collecting irrigation water.

• Three key contributing factors to the two main causes are identified :

- the lack of maintenance and monitoring by the irrigator, a significant flow of irrigation water occurring in a clogged supply channel, and the failure of the field’s water to drain through the recovery canal ;
- lack of maintenance by the infrastructure manager of the irrigation and drainage water recovery ditch ;
- communication gap between irrigators and the infrastructure manager.

The BEA-TT (French Bureau of Investigation and Analysis for Land Transport) issues five recommendations on the following topics to prevent this type of accident :

• Take advantage of work on the embankment and road restoration to rebuild the irrigation water recovery canal ;
• Ensure that, across the entire railway network, greater emphasis is placed on the maintenance of hydraulic structures (ridge ditches in particular) during regular monitoring of earthworks. Strengthen the maintenance guidelines on this subject by including technical monitoring of these operations ;
• Conduct training and provide information to residents through the Authorized Syndicate Association (ASA) on proper management and monitoring of runoff during open-field irrigation operations, particularly when re-watering after several years ;
• Implement systems, where available and feasible on the ground, to limit the water flow when irrigation gates are opened, in order to ensure better control of the water volume on the field in this type of irrigation ;
• Raise awareness among new landowners with "open field" irrigation rights, located near the railway line, about the risks inherent in this irrigation method with respect to the railway and the maintenance of the equipment ;
• Re-establish effective communication between the ASA (Association Syndicale Autorisée - Autonomous Syndicate Association) and SNCF (French National Railway Company) so that, in the event of overflows, an organization can be put in place by SNCF Réseau (French National Railway Network) and the ASA to intervene quickly on site. This could involve conducting adapted, faster, and more efficient patrols in the event of exceptional weather or incidents. More innovative means could be used, such as railcars, drones, photography, etc. ;
• Improve knowledge of heritage and study the strengthening of the security of engineering structures against the risk in case of derailment, in particular structures not providing sufficient clearance according to UIC sheet 777-2-2 (for example safety rail, guide wall, etc.).