A train hit the buffers at London Bridge station because the driver had a “microsleep” due to fatigue, an investigation has found.
No passengers were injured when the Southern Railway eight-carriage service, from Victoria via Crystal Palace, crashed into the buffers on platform 12 at about 3.45pm on December 13, 2024.
The driver, who has not been named, was also unharmed. The train had been travelling about 2.3mph, suffered minor damage.
However the incident has sparked concerns at the way GoVia Thameslink, the UK’s biggest rail franchise, manages driver fatigue.
The issue of drivers suffering from a “microsleep” first came to public attention at the time of the Croydon tram derailment in 2016 that resulted in the death of seven passengers and injury to 62 others.
A report by the Rail Accident Investigation Branch said that, in the 22 days preceding the London Bridge incident, the train driver was meant to have 12 rest days but ended up working nine of them, leaving only three rest days in more than three weeks.
The train had been travelling at 13.3mph when it entered the platform and its speed gradually reduced as it progressed towards the buffer stop.
When it was about 3.5 metres from the buffers and travelling at a speed of 6.8 mph, the driver applied the emergency brakes but was unable to prevent the collision.
The RAIB said the crash occurred because the driver did not apply the brakes in time “almost certainly because they experienced a microsleep, due to fatigue”.
Its report said two “probable causal factors” were that the staff roster was constructed “in a way that increased the risk of fatigue” and that the driver had also worked many rostered rest days in the period up to the accident, further increasing the risk of fatigue.
A possible causal factor was that the driver had less than their normal amount of sleep p- about seven hours - the night before.
In addition, none of the engineered protection systems fitted to the train intervened to prevent the collision.
The report said: “The Train Protection and Warning System fitted on approach to the buffer stops did not automatically apply the train’s brakes because the train was travelling below the set intervention speed.
“Other safety systems fitted on board the train could not detect the short loss of driver alertness that occurred.
“A probable underlying factor to the accident was that the management of fatigue risk by Govia Thameslink Railway, the company operating the Southern Railway franchise, was not sufficiently effective and that it had not adopted some elements of industry good practice in fatigue risk management.
“A second underlying factor was that there are no safety systems currently fitted to mainline trains which can detect and mitigate short losses in driver alertness.”
RAIB has told GoVia Thameslink to improve its fatigue management process and follow industry best practice.
Samantha Facey, Govia Thameslink Railway’s safety, health and security director, said: “Safety is always our number one priority and we’re determined to learn from every incident to improve our safety standard for our people and our customers.
“We’re committed to making sure our staff are fit and alert when they’re at work – in August we updated and improved our fatigue risk management standard to help us manage fatigue more effectively, which includes reports from staff related to tiredness.
“We’ve also set up stronger working groups with staff representatives, and we’re now using robust scientific modelling to plan staff shifts so we can spot and prevent fatigue before it becomes a risk.”
At London Bridge, platforms 1 to 9 are “through” platforms used by trains operating to and from Charing Cross/Cannon Street and Blackfriars. Platforms 10 to 15 are terminus platforms with buffer stops.
Trains operated by Southern only operate into platforms 10 to 15.
The train involved was a class 377 electric unit. It was formed of two four-car units.
The driver joined Southern in 2019 as a new train driver and is based at Norwood depot.
Prior to the crash, the driver recalled beginning to feel tired at Crystal Palace station and recognised the need to focus and remain alert.
Fifteen minutes later, at New Cross Gate station, the last station before London Bridge, the driver stated that they got up and moved around to help them to maintain alertness. On the journey towards London Bridge, they opened the cab window.
A microsleep is a temporary sleep episode that lasts for 15 seconds or less. During a microsleep the brain involuntarily goes to sleep, and people may awake from it suddenly with a jolt. Microsleeps are characterised by a person briefly closing their eyes and experiencing a lapse in attention.
Microsleeps are often caused by fatigue but can occur at any time. They are more likely to occur when someone is sleep deprived or during repetitive and monotonous tasks.
In October 2021, a London Overground train hit the buffers at Enfield Town station at 7.7mph. The RAIB found that the driver was fatigued at the time and had taken recreational drugs.
In the aftermath of the Croydon tram crash, Transport for London fitted the “Guardian” system to its fleet of trams.
This measures percentage of eye closure, face expression, head position and gaze direction. When it detects that attention has decreased below set parameters, it triggers an alert to the driver, in the form of an audible warning and seat vibration.
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