Channel Tunnel fire investigation recommendations 12 Jun 2016

An investigation into the January 2015 freight train fire inside the Channel Tunnel concludes that an over-height aerial on a lorry triggered an electrical arc near the tunnel’s overhead wires. A delay of 23 minutes in activating the fire alarms meant that by the time the train was halted it had overshot by 1,000m the last of two SAFE stations where specialist and automatic fixed fire-fighting equipment is installed.

Instead it was 3.5 hours until French firefighters arrived on the scene to start tackling the fire.

Channel Tunnel track layout

As a result of the incident six key recommendations for improvements have been made to the operator, Eurotunnel, chief among which is a call to ensure trains that are on fire will stop inside the purpose-built fixed fire fighting stations (FFFS).

The report also recommends ongoing monitoring of advances in fire detection technology and systems. In addition, the report calls for Eurotunnel to optimise the use of the emergency transport system in the service tunnel.

During the 17 January 2015 incident, the France-bound freight shuttle finally stopped in the French section of the 53km-long Channel Tunnel. The official investigation was led by the French Government’s Bureau d’Enquetes sur les Accidents de Transport Terrestre (BEA-TT), supported by the Rail Accident Investigation Branch (RAIB) of the UK.

Investigations revealed there were two separate arcing incidents, both of which caused the train to stop. The first, at the UK portal, was caused by the over-height aerial which appears to have led to smouldering and smoke inside the cab of the lorry.

Locations of the SAFE stations

The investigators report that at the time there were no requirements for trains to be inspected after being brought to a standstill by trip-out of the overhead line. The developing fire, therefore, went undetected and the train was allowed to restart, at reduced speed.

While the Eurotunnel control centre gathered information following the initial trip-out at the portal, it became too late to stop the train before it passed through the second, and last, SAFE station at the end of the approximately 17km-long Interval 4 of the North Running Tunnel.

With the focus in the control centre now focused on fire procedures, no attempt was made to re-energise the overhead power line, which investigators think might have allowed the train to exit the tunnel. Eurotunnel’s safety protocols prevent a train being reversed back to a SAFE station. The operator has since revised its procedures and trains are automatically stopped at the first SAFE station for further inspection following trip-outs at tunnel portals.

SAFE water-mist fire suppression system demonstration

The SAFE (Station Attaque FEu) stations were retrofitted into the Channel Tunnel after previous fire incidents caused damage to the tunnel lining. On this occasion, however, and after the SAFE system was overshot, it took 3.5 hours before the emergency services were ready to start firefighting. The investigators further claimed that a “lost” hour of effective response time was caused by issues relating to service tunnel vehicles and their drivers.

In the event the smouldering fire was contained before developing into a serious blaze. Only minor damage was caused to a short section of tunnel soffit, although two lorries were destroyed.

The Channel Tunnel has a total of four SAFE stations – two in each running tunnel, located at about the third-way points along each alignment. Completed in 2010 at a cost of €20 million, each can hold an entire truck shuttle train and automatically douse and suffocate any blaze with a high pressure, micro-mist.

The SAFE stations are designed to improve overall fire safety in the Channel Tunnel and prevent major infrastructure damage, as experienced in major fires in 1996 and 2008, respectively. There was also a lesser fire in 2006.