The Rail Accident Investigation Branch (RAIB) has released a report into its preliminary examination about a train travelling at excess speed at Grantham South Junction.

The incident occurred at around 08:25 on 25th February 2025 when the 07:00 Hull to London Kings Cross London North Eastern Railway service, train reporting number 1A12, passed Grantham South Junction in at excess speed, known as an overspeeding incident.

The train had stopped as scheduled at Grantham station, and on departure the signal indicated that the train would be diverted at Grantham South Junction from the main line onto a parallel slow line.

The permissible speed on the main line at Grantham South Junction is 115 mph (184 km/h), but for trains diverging from the main line, there is a permanent speed restriction of 25 mph (40 km/h). Train 1A12 diverged from the main line at the junction at around 55 mph (87 km/h).

Despite the excess speed, there were no reported injuries to passengers, but minor injuries were received by staff on board the train. The Rail Accident Investigation Branch was informed about the incident soon afterwards.

The preliminary examination into the incident found it highly likely that factors present in this incident were similar to those identified during investigations into a train overspeeding at Spital Junction in Peterborough on 17th April 2022, (RAIB report 06/2023) and a similar event at the same location on 4th May 2023 (RAIB report 10/2024).

Although some recommendations from those investigations are still open, the Rail Accident Investigation Branch has concluded it is unlikely any further investigations will result in new recommendations that will improve railway safety. Consequently, there will be no further investigations into the incident, neither will an investigation report be produced.

However, this incident highlights issues with train drivers being completely relied on to react appropriately to junction or route indicators when they diverge on low-speed turnouts from high-speed through routes. As higher-performing train fleets are introduced, there may be an increased risk, which may be exacerbated by routing patterns as the railway network becomes ever busier.

The Rail Accident Investigation Branch has written to the Office of Rail and Road so that it can take this incident into account when considering industry responses to recommendations made in reports into the Spital Junction incident. It also raises wider questions around protecting against overspeeding.