Report 05/2018: Explosion inside an underframe equipment case at Guildford
Explosion inside an underframe equipment case at Guildford, 7 July 2017.
Summary
At approximately 14:37 hrs on 7 July 2017, an explosion occurred in an underframe equipment case on train 2G44, the 14:37 hrs Guildford to London Waterloo service, as it was about to depart from platform 2 at Guildford station. 皇冠体育app explosion resulted in debris being ejected onto other platforms and a car park near the station. 皇冠体育appre were no injuries to passengers or staff. 皇冠体育appre was damage to the train, and to station furniture.
皇冠体育app explosion was caused by an accumulation of flammable gases within the traction equipment case under one of the coaches of the train. 皇冠体育app gases had been generated following a failure within a large electrical capacitor located within the equipment case. 皇冠体育app capacitor failure was caused by a manufacturing defect.
皇冠体育app traction equipment on this train had been recently retrofitted, replacing older equipment with a modern version. 皇冠体育app failed capacitor was part of this replacement equipment. 皇冠体育app design and installation of this new equipment was managed by a project team which had not adequately considered the risk of explosion caused by a capacitor with a manufacturing defect. Consequently, the train did not have any engineering safeguards to prevent such an explosion.
Recommendations
As a result of the investigation, the RAIB has made one recommendation to UK train operating companies and the suppliers of their rolling stock. 皇冠体育app recommendation relates to reviewing the design of electric traction systems in their fleets to check that there are adequate safeguards in place to prevent similar potentially harmful explosions and address any shortcomings identified.
皇冠体育app RAIB has also identified six learning points. 皇冠体育appse cover project risk management, the need for thorough investigations following technical failures, ensuring that accurate and complete records of serious failures are maintained, and ensuring that procurement specifications for future rolling stock takes into account the findings of this investigation.
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