Conventional fire on a CGH2 trailer

Early in the morning a hydrogen tube trailer experienced a tire fire and pulled onto the road shoulder. The driver attempted to extinguish the fire with the fire extinguisher on the vehicle. Heat from the fire caused seats on the isolation valves of two tubes to deform and the welded stainless steel manifold to crack, releasing hydrogen, ignited then by the tire fire.
The driver was unable to extinguish the fire and called the emergency number. Emergency responders closed the highway in both directions for several hours.
There were 2 injuries, the material damage was limited to the trailer.

The INITIATING CAUSE was a conventional fire on tire following brake failure.
The ROOT CAUSE can be probably related to ageing of the tires or of the brake system. Maintenance procedures are in place to avoid these hazards. Moreover, tube protection from conventional fires seems having been not very effective (design shortcoming).

tire, Piping, Fittings

the refilled trailer had just been connected to the customer pressure reducing station

no fatalities, no injuries, and damage was limited to the trailer

The conventional brake fire which started this incident did not produce a heat input to the CGH2 tubes to cause their internal pressure to raise above the limit set by the pressure relief system. The burst disc did not open. The only damage caused by the fire was to a seal fitting, which caused a leak with limited consequences.
Nevertheless, other cases started with conventional fires caused the venting of the whole hydrogen load, because the pressure relief valve were thermally or pressure-activated. Such a scenario has to be avoided when the trailers are in a confined space, such as a tunnel.

The company investigated the possibility to replace the decking on the floor above the tires, now made of a aluminium plate, with a steel plate. The outcome of this analysis is unknown.