A track defect was present in the vicinity of the train derailment near Lewes in East Sussex, where 30 individuals sustained injuries last week, according to the Rail Accident Investigation Branch (RAIB).
An interim report released by the RAIB indicates that CCTV footage from earlier services on the line captured the fault, described as a 'track geometry irregularity.' Preliminary analysis of the derailed Southern train's onboard data recorder shows it was traveling at approximately 65 mph as it approached the point of derailment on August 13. The train, en route from London Victoria to Eastbourne, was carrying about 150 passengers when three of its eight carriages overturned, trapping some passengers.
Of the 30 injured, 20 required hospital treatment, the RAIB stated. Investigators are examining several factors, including the weather conditions on the day of the incident, which were hot and sunny. The probe will also assess the condition of the track, embankment, the train itself, and the effectiveness of any measures implemented to mitigate potential issues arising from hot weather.
Investigators are considering whether track expansion due to the heat may have caused warping. Aerial views of the derailment site show the damaged carriages, with one carriage resting on its side. British Transport Police were on scene managing the investigation following the incident.
