Investigator releases initial findings on Lewes train derailment
RAIB report examines factors leading to accident
The Rail Accident Investigation Branch (RAIB) has published its initial report on the derailment of train 1F34 near Lewes station in East Sussex, last Thursday (13th August 2026).
The accident involved an eight-vehicle passenger service operated by Southern (Greater Thameslink Railway). The rear three vehicles of the train derailed and overturned, leading to injuries for 30 passengers, with 20 requiring hospital treatment, 2 seriously.
The RAIB's report highlights a track geometry irregularity at the derailment site, corroborated by CCTV footage from the train and other services. The report outlines ongoing analysis of factors such as track conditions, maintenance records, and weather impact.
Preliminary data from the train’s on-board recorder shows the train was travelling below the maximum permitted speed, with brakes applied by the driver as it approached the derailment point. The RAIB's comprehensive investigations are independent of those conducted by the railway industry and regulator.
The report also examines the state of the embankment, noting previous movements and assessing the effects of sustained hot weather on the track and surrounding infrastructure. RAIB continues to evaluate evidence regarding the accident sequence and potential underlying issues.
RAIB is committed to identifying causes and offering safety recommendations based on its findings. The initial report is part of a broader investigation, with a final report to be published upon conclusion.