A train travelling at over 100mph through Kings Langley crashed into equipment left by workers by accident, a government investigation has found.

At around 6.43am on April 25, the Wolverhampton to London Euston service crashed into a temporary road-rail vehicle access point (RRAP) at 124mph near Kings Langley station.

An investigation by the Rail Accident Investigation Branch found the equipment had been used for work on overhead electric lines the previous evening, but became wedged under the passing train the next morning spraying ballast and parts of a broken brake pad across other lines.

CCTV from the train showing the equipment left between the train lines.CCTV from the train showing the equipment left between the train lines. (Image: RAIB) The report published yesterday (July 24) said the drivers first became aware of an issue when the train showed a loss of electrical power, while staff further along heard a loud noise followed by the deflation of a suspension airbag in the last coach.

The debris damaged the windscreen of the 6.16am service from London Euston to Edinburgh Waverley which was travelling at around 107mph on an adjacent line, and also landed on the platforms at Kings Langley station which were unoccupied at the time.

Nobody was injured and neither train derailed, but it forced both of them to be taken out of service.

CCTV from the passing service which shows debris and a dust cloud from the collision.CCTV from the passing service which shows debris and a dust cloud from the collision. (Image: RAIB) The damaged southbound train had to be held at Watford Junction, meaning other services became congested as they had to use different lines to get around it.

RAIB investigators found that workers used torches to collect the equipment from the engineering works the previous evening, but did not check if all 20 pieces had been picked up and missed the section that would later cause the accident.

Remains of the temporary RRAP found under the train (left) and the brake pad found on Kings Langley station platform (right).Remains of the temporary RRAP found under the train (left) and the brake pad found on Kings Langley station platform (right). (Image: RAIB)

They also said the RRAP may have been installed higher than allowable due to the high level of gravel around the rail lines, meaning there was not enough clearance for trains to pass over it.

Location of where the crash took place.Location of where the crash took place. (Image: RAIB) The investigation found that the employee in charge of the engineering works and senior members of the track team were experienced and had the “correct competencies” for the task.

It blamed instead the collision on the decision to use a temporary RRAP, its “poor” fitment to the track, bad lighting conditions and a lack of training as all contributing reasons to the incident.