The train struck a section of redundant rail that had been left on the tracks on the approach to Walton-on- Thames station last March.

It was travelling at around 85 mph and the front coach derailed as the train came to a stop around 500 metres after hitting the obstruction.

The Rail Accident Investigation Branch found the redundant rail had inadvertently been left there by a team that had completed work in the area over the previous weekend.

Checks undertaken after the work was completed did not identify that a section of redundant rail was in a potentially hazardous position before the railway was handed back for normal operation.

This was because no person in charge had supervised the work and because a track handback engineer had not been effectively briefed as to what work had been undertaken before they inspected the track.

The board has asked Colas Rail to review its processes related to collecting redundant material when working on or near the line.

Network Rail has also been asked to review the rules and standards relating to how tasks delivered in complex work sites are co‑ordinated and supervised.

Andrew Hall, Chief Inspector of Rail Accidents said: “Although no one was hurt on this occasion, the train could easily have deviated from the line of the track and struck other trains or objects.

“Maintenance work is often carried out at night which makes ensuring the line is subsequently safe for the passage of trains particularly challenging.

“The risk is very clear. Unfortunately, this accident happened because that risk was not effectively managed.

“This, following other similar recent incidents, should serve as a stark reminder of the importance of effectively managing the risk of objects being left on the track after overnight maintenance.”