STORY
Rail accident investigators have identified a track geometry irregularity at the location where a Southern passenger train derailed near Lewes, although the cause of the accident has not yet been established. The 14:24 London Victoria to Eastbourne service derailed around one mile north of Lewes station at approximately 15:54 on 13 August. The rear three vehicles of the eight-carriage train derailed and overturned, coming to rest on their sides on the railway embankment. Around 150 people were on board, with 30 injured and 20 requiring hospital treatment, some with serious injuries.
Preliminary analysis by the Rail Accident Investigation Branch shows that the train was travelling at around 65mph as it approached the derailment, below the 70mph maximum permitted speed at that location. Investigators said marks on the rails were consistent with the wheels of the rear vehicles climbing over them. CCTV footage from the derailed train and services which had passed through the area earlier that day shows that a track geometry irregularity was present on the immediate approach to the point of derailment before the accident. Investigators have also found evidence of previous track maintenance in the area and have received reports from passengers of rough riding at the same location on earlier trains.
The RAIB said its investigation will examine the precise mechanism of the derailment, the condition, inspection and maintenance of the track and embankment and whether sustained hot and dry weather was a relevant factor. The embankment is constructed from clay over alluvial deposits which can move as their moisture content changes, although investigators stressed that there is currently no evidence of a significant embankment slip immediately before the accident. The investigation will also consider the condition and crashworthiness of the train, the emergency response and any action taken following previous relevant safety recommendations.