Collision and fire from a CGH2 trailer

A CGH2 tube trailer-tractor was hit at the rear by another vehicle, an empty flatbed trailer-tractor. Because of the collision, at least two tube safety valves were broken. The released hydrogen ignited and the fire engulfed the other eight cylinders, which over-heated, causing the pressure relief valve to activate and release the whole content (350 kg).

The INITIATING CAUSE was the damage to the pressure control system caused by the collision caused by another vehicle.
The safety measures operated as expected.
Beyond an evident personal responsibility of one driver in the collision, the ROOT CAUSE is difficult to determine. A better design could guarantee stronger protection of the trailer pressure control system.

safety valve

The trailer consisted of ten tubes.

The actions are not reported. Time of the fire also unknown.
Since this was a case of immediate release and ignition, It is very probable that the fire was left extinguish, possibly by cooling the tubes, before starting to intervene to recover the vehicles.

The safety measures operated as expected.
A better design of the protective barrier at the rear of the trailer could guarantee stronger protection of the trailer pressure control system, and therefore the reduction of the probability of an escalation. However, it is difficult to take into account all possible crash scenarios generated by traffic. Vehicle and human protection strategies are based on highly standardised assumptions, which do not cover all possible cases, in term of speed, number and mass of vehicles involved, their relative position and direction, etc..