Overspeeding at Cambridge Junction
Overspeeding at Cambridge Junction, Hitchin, Hertfordshire, 11 December 2025.
Forward-facing CCTV from the train involved showing the junction signal set for the diverging route (image courtesy of Great Northern).
At 10:39 on 11 December 2025, train reporting number 1T20, the 10:12 London Kings Cross to Ely service, operated by Great Northern (a trading name of Govia Thameslink Railway Ltd), was involved in an overspeeding incident at Cambridge Junction.
At the junction, the train was routed from the Down Slow line over points for a diverging route. These points have a permanent speed restriction of 25 mph (40 km/h). CCTV evidence shows that the signals for this route displayed the expected indications; however, the train traversed the points at 56 mph (90 km/h). This caused the train to lurch sideways, with several passengers falling out of their seats as a result. The permissible speed for a train remaining on the Down Slow line is 75 mph (121 km/h).
No injuries were reported as a result of the incident and no damage was caused.
We have undertaken a preliminary examination into this incident. We have also reviewed the circumstances of two similar incidents which took place at Grantham South Junction on 25 February 2025 and 26 September 2025, as well as two previous RAIB investigations into overspeeding events that occurred at Spital Junction, Peterborough on 17 April 2022 (report 06/2023) and 4 May 2023 (report 10/2024).
As these previous investigations still have open recommendations, RAIB has decided to publish a safety digest for this incident.