Body makes recommendations for safety in report after low-speed Bletchley train derailment

The government’s Rail Accident Investigation Branch (RAIB) has made safety recommendations after a low-speed train derailment in Bletchley last summer.

The incident happened at about 12:27pm on 26 June 2025, when an out-of-service London Northwestern Railway passenger train derailed as it passed over Denbigh Hall South Junction between Bletchley and Milton Keynes Central stations.

The train was travelling at a speed of around 15mph when it came off the tracks. RAIB said that the affected train had developed a technical fault that had forced the early termination of a Birmingham to London train service, with the rolling stock returning to the operator’s main depot in Northampton for further checks when the error saw it come off the tracks.

There were no injuries to any of the four members of train crew on the train but damage was caused to the train and to railway infrastructure. The incident also caused major delays on the West Coast Main Line, as the line was closed completely for an hour before the fast lines were re-opened. The slow lines on which the train derailed were partially re-opened on 29 June and then fully re-opened on 7 July.

According to the investigation, the incident happened when the train was routed over points at Denbigh Hall South Junction that were not formatted properly for the train to pass over as per the route that had been agreed upon.

The report’s summary read, “The train derailed on switch diamond points which were in an unsafe position for the direction that the train was travelling over them. It had been necessary for the train to make a wrong-direction movement due to a fault which had prevented the driver from moving the train from the cab at one end.

“Once the need for the wrong-direction movement was identified and agreed, signalling staff at Rugby Signalling Control Centre proposed and then implemented a path for the train which they did not realise was invalid. Subsequent checking activities by these signalling staff did not identify this. When the train then arrived at the junction, no one in the train’s leading cab noticed that the switch diamond points were in an unsafe position for the train to pass over them.”

The report also went on to say, “RAIB also observed that the Rule Book did not cover the specific circumstances of this wrong-direction movement. This meant that the signaller was unintentionally not following the rules when they had authorised the driver to pass a signal at danger at the start of the movement.”

RAIB said that they have made four recommendations as a result of this investigation.

In the statement around the release of the report, they said the recommendations would require further training to avoid similar such incidents happening in the future.

RAIB said in their statement, “The first is addressed to Network Rail to provide training to signallers on the tools and techniques that can be used when setting up and checking the proposed path for a train to take during an out‑of‑course event. The second and third, addressed to Network Rail and West Midlands Trains respectively, are to develop training for staff to give them the appropriate level of knowledge and understanding of switch diamond points to allow them to undertake their duties in accordance with the Rule Book. The fourth is addressed to the Rail Safety and Standards Board, in consultation with the rail industry, to consider whether the Rule Book needs to account for the scenario where a signal at danger is located at, or near to, the start of a planned wrong‑direction movement.

“RAIB also identified four learning points. They cover staff understanding the impact that personal issues can have on themselves; the importance of staff taking the time to stop and check again, or continuing to challenge if unsure; reminding signallers that they should ask a competent person, if present, to check the path that they have set up for the wrong-direction movement; and reminding drivers that during a wrong‑direction movement, they can approach a junction at a speed slower than 15 mph (or 25 km/h) to give themselves more time to make sure, if possible, that any points, switch diamonds or swing-nose crossings are in the correct position.”