A passenger was thrown to the floor and others nearly fell over when an Elizabeth line driver became “confused” and went through a set of points too quickly.
An investigation found the train, which was travelling from Heathrow airport to Shenfield, passed through the points at 45mph – 20mph more than the maximum safe speed.
The Elizabeth line is the single busiest rail line in the country, and is used for more than 770,000 journeys on a typical weekday.
A report by the Rail Accident Investigation Branch said this caused the nine-carriage rush hour train to “jolt sideways”.
It said: “Although there were no reported injuries, CCTV footage from inside the train shows that the sudden movement resulted in some passengers losing their footing and that at least one passenger fell to the floor.”
The incident happened at around 8.10am on September 24 last year, just east of Manor Park station in east London.
The driver was taking a different route to that planned because of a track circuit failure on the normal route.
The RAIB said the incident happened “because the driver became confused about the train’s location after being routed off its booked route.
“As a result, the driver did not reduce the train’s speed to the 25mph limit required over the points.”
The watchdog said the 25mph sign was “incorrectly placed, inconspicuous and dirty” – making it hard for the driver to spot.
Visibility problems were compounded by the sign being under a bridge and partially obscured by lineside equipment. It was also “covered in dirt, further reducing its conspicuity and legibility”, the RAIB said.
The train did not derail during the incident and no damage was caused to the track infrastructure or the train, which continued on its journey to Shenfield.
The RAIB, which has previously highlighted similar “overspeeding” incidents elsewhere on the rail network, including at Spital junction, Peterborough, in 2023, when a train went through an area limited to 25mph at 66mph.
The Spital junction incident resulted in some passengers being thrown from their seats and receiving minor injuries.
The RAIB said the Manor Park incident demonstrated the importance of drivers refreshing their route knowledge, especially where alternative routes exist.
It also warned Network Rail to ensure that lineside signs are positioned in the correct location and that they are visible and legible to drivers.
Howard Smith, director of the Elizabeth line, said: “We apologise to customers who were on board the train during this rare incident.
“Our operator, MTR Elizabeth Line, immediately informed the Office of Rail and Road and the Rail Accident Investigation Branch.
“Safety is our top priority and MTREL have already made changes to their procedures in line with the RAIB's recommendations.”
The Elizabeth line is operated for Transport for London by MTR. From May, the line will be run by a new operator, GTS Rail Operations Ltd, a joint venture between Go Ahead Group, Tokyo Metro and Sumitomo Corporation.
Other than the central operating section between Abbey Wood and Paddington, the Elizabeth line runs on track that is managed and maintained by Network Rail.
On the day of the incident, the driver booked on for duty at 4:33am at Plumstead sidings. The train initially ran from Abbey Wood to Heathrow Airport before becoming the 6:50am service from Heathrow Terminal 5 to Shenfield.
The train departed Manor Park at approximately 8:09am. “The driver… did not realise that there were points ahead for which the train’s speed would have to be 25 mph,” the report said.
“The overspeed was reported to MTR control by a member of staff travelling on the train at the time of the incident.
“The driver felt the train jolt when it traversed the points but did not believe that this was severe enough to report.”
