A train driver, fatigued due to unexpected childcare responsibilities, fell into a momentary microsleep moments before his train collided with the buffers at one of Britain's busiest railway stations, an official investigation has concluded.
The Incident: A Low-Speed Collision
The Rail Accident Investigation Branch (RAIB) reported that the incident occurred at London Bridge station at 3.45pm on 13 December 2024. The Southern Railway service, operated by Govia Thameslink Railway (GTR), was arriving at platform 12 when it struck the end-of-track buffers.
Data from the train's onboard recorder showed it entered the platform at 13.3mph and was slowing down. At the point of impact, it was travelling at just 2.3mph. The driver applied the emergency brake when the train was only three-and-a-half metres from the buffers, but it was too late to avoid the collision.
Fortunately, the low speed meant there was only minor damage to the train and station infrastructure. No passengers or staff were injured in the event.
The Root Cause: Disrupted Sleep and Overtime
The RAIB's investigation pinpointed driver fatigue as the direct cause. The unnamed driver's normal routine before an early afternoon shift was to stay in bed until around 9am. However, on the day of the incident, he had to get up at 7.30am because of sudden changes to his childcare arrangements at home.
This resulted in him getting less sleep than usual. The report states the driver began to "feel tired" and recognised he needed to focus when the train stopped at Crystal Palace station, some 26 minutes before the crash at London Bridge. Despite this awareness, he felt able to continue.
Compounding the issue was the driver's work pattern. In the 22 days leading up to the accident, he was scheduled for 12 rest days but had worked on nine of them. This practice of volunteering for paid extra shifts is common across the industry to maintain services but increases the risk of cumulative fatigue.
Safety Systems and Company Response
The investigation noted that existing train protection systems did not activate to prevent the collision because the train was travelling below the minimum speed threshold for intervention. Other safety mechanisms also failed to detect the driver's brief lapse in alertness.
In response to the findings, the RAIB has recommended that GTR enhances its fatigue management processes. Samantha Facey, GTR's Director of Safety, Health and Security, stated that safety is the firm's top priority and outlined steps already taken.
"In August, we updated and improved our fatigue risk management standard," she said. "We're now using robust scientific modelling to plan staff shifts so we can spot and prevent fatigue before it becomes a risk. All of this is part of our ongoing efforts to meet the RAIB's recommendations."
The case highlights the ongoing challenge of managing human factors and roster patterns in ensuring railway safety across the UK network.
