The United Kingdom Rail Accident Investigation Branch will publish a safety digest after a Great Northern train oversped through a diverging junction at Cambridge Junction on Dec. 11, 2025, traveling 56 mph in an area with a 25-mph limit.
Investigators said the 10:12 a.m. London King’s Cross to Ely service, reporting number 1T20, was routed from the Down Slow line over points set for a diverging move at 10:39 a.m.
Forward-facing CCTV shows the signals displayed the expected indications. However, the train traversed the turnout more than twice the permitted speed, causing a pronounced sideways lurch that knocked several passengers from their seats.
No injuries or damage were reported. The permissible speed for a train remaining on the Down Slow line at that location is 75 mph.
RAIB conducted a preliminary examination and reviewed two similar overspeeding events at Grantham South Junction on Feb. 25 and Sept. 26, 2025, as well as earlier investigations into overspeeding at Spital Junction, Peterborough, on April 17, 2022, and May 4, 2023. Because recommendations from those prior inquiries remain open, the agency will issue a safety digest rather than launch a full investigation into the Cambridge incident.
The safety digest will set out the key facts and lessons without duplicating existing recommendations.
RAIB said the decision reflects continuing work across multiple overspeeding cases involving diverging junctions where signals and routes were correctly set. Approach speeds were not reduced to the lower turnout limits.
Be the first to comment