Clermont-Ferrand english summary (fire)

At around 7:12 a.m. on 26 December 2009, the driver of tram no. 15 on the Clermont-Ferrand tramway system noticed smoke emanating from inside one of the modules. He returned the tram to a siding at the "La Pardieu Gare" terminus of the line. Several minutes later, the tram burst into flames. The fire lasted about thirty minutes.
There were no casualties of the fire, but the tram was completely destroyed. Minor damage was caused to the infrastructure.

The direct cause of the accident was the seizing of a brake due widespread corrosion of the brake pad actuating system, whose design and manufacture failed to ensure its watertightness.

The heat radiated by the heating of this brake in its “on” position led to the pyrolysis of the mudguard and the adjacent communication bellows. The pyrolysis gas then caught fire and the fire spread to the whole tram.
The spreading of flames in the passenger area was facilitated by the short distance and lack of an efficient firewall between the braking system and the communication bellows.
The fire spread easily to the rest of the tram due to the presence of materials that did not provide a level of fire protection equivalent to that specified by the NF F 16-101 standard relating to the fire behaviour of railway rolling stock.

The accident analysis led BEA-TT to issue six recommendations concerning the four following topics :
- The design of the mechanical brakes on the tram
- Insulation between the passenger area and the mechanical braking system
Fire behaviour of materials used in the construction of the tram
- Organisation of feedback

In addition, BEA-TT encourages manufacturers to develop and use materials for the communication bellows whose burning behaviour and smoke index are an improvement over current devices of this type.