At around 17:31 hrs on 22 February 2015, a high speed passenger train (HST), the 16:34 hrs First Great Western service from London Paddington to Penzance, struck and ran over part of the fallen masonry parapet of an overline bridge at Froxfield, Wiltshire.
The train was fully loaded with around 750 passengers and was travelling at a speed of 86 mph (138 km/h) when the driver saw the obstruction. He applied the emergency brake but there was insufficient distance to reduce the speed significantly before the train struck the parapet. The train did not derail and came to a stop around 720 metres beyond the bridge. There were no injuries. The leading power car sustained damage to its leading bogie, braking system, running gear and underframe equipment.
The immediate cause of the collision was that the eastern parapet of Oak Hill Road overline bridge had been pushed off and onto the tracks, by a heavy goods vehicle which had reversed into it. The train had not been stopped before it collided with the debris because of delays in informing the railway about the obstruction on the tracks.
RAIB has made four recommendations relating to the following:
- installation of identification plates on all overline bridges with a carriageway unless the consequence of a parapet falling onto the tracks or a road vehicle incursion at a particular bridge are assessed as likely to be minor
- enhancing current road vehicle incursion assessment procedures to include consideration of the risk from large road vehicles knocking over parapets of overline bridges (two recommendations)
- introduction of a specific requirement in a Railway Group Standard relating to the onward movement of a train that is damaged in an incident, so that the circumstances of the incident and the limitations of any on-site damage assessment are fully considered when deciding a suitable speed restriction, especially when there are passengers on board.
RAIB has also identified two learning points, one for police forces regarding the importance of contacting the appropriate railway control centre immediately when the safety of the line is affected and the other for road vehicle standards bodies and the road haulage industry about the benefits of having reversing cameras or sensors fitted to heavy goods vehicles.
Response to recommendations:
- RAIB will periodically update the status of recommendations as reported to us by the relevant safety authority or public body
- RAIB may add comment, particularly if we have concerns regarding these responses.