A FUEL leak in one of the gensets on Vivarail’s prototype Class 230 D train was the cause of a fire on the train, the company’s report into the incident has concluded.

The fire occurred as the unit underwent main line testing between Leamington Spa and Coventry on 30 December 2016. Testing on the main line had begun in November, ahead of a planned introduction into service on the Coventry to Nuneaton line in February. However, following the fire, the unit’s trial on this route, which was backed by local authorities and the West Midlands Combined Authority in conjunction with operator London Midland, has been cancelled.

An initial report into the incident, released in mid-January, revealed that the fire occurred in a genset fitted to vehicle No 300101. Vivarail says the fuel leak that caused this was ignited by a hot body, likely to have been the turbocharger. The fuel leaks were likely caused by a repair intervention on the genset by the supplier, which was not spotted due to a lack of suitable test procedures post repair work. The company plans to implement an immediate additional test regime to ensure that gensets are tested prior to fitment to a vehicle to check that there are no fuel leaks when the engine is on full power.


The report says that several contributory factors led to the fire being more intense and burning for longer than might have been the case. These include the design of the low-pressure fuel system, which is likely to have fuelled the fire with fresh diesel, the design of the fire suppression system, which proved ineffective at stopping the fire, and the fact that the manual hand isolation cock was sited too close to the genset, preventing the train crew operating it while the genset was on fire.

Vivarail’s final report confirms the conclusions of the interim report that the passenger saloon of the vehicle was unaffected by the fire, indicating that the fire barrier beneath the saloon was effective. The engine itself suffered considerable damage, although following an inspection of the underframe Vivarail believes the vehicle bodyshell is fit to be repaired for reuse.

Vivarail says a series of actions will take place with the intention of ensuring that a fire of this nature never recurs and improving the resilience of the vehicle systems to ensure continued operation for 15 minutes in the event of an incident. These include a review of genset maintenance and repair practices and a design review of the genset to address weak points identified by the investigation. Vivarail says some actions are already underway, and that all will be completed and implemented prior to the unit being made available for main line running.