Fire from CGH2 cylinders on truck

A truck was transporting 35 compressed hydrogen cylinders (7 m3) to a sales office when it suddenly got a flat tire, causing the truck to overturn. The cylinders were thrown onto the road and gas leaked from the base of three valves, causing one of the cylinders to ignite and burn.

The INITIATING CAUSE was the failure of a conventional component (tyre) .
The ROOT CAUSE was probably the lack of efficient restraint and protection of the cylinders on the which were not designed for impacts coming from vehicle roll-over.

valve base, cylinder

Assuming that the value of 7 m3 refers to the 'water' capacity of all 35 cylinders, assuming a pressure or 200 bar, the truck was transporting approximately 100 kg of hydrogen.

Due to the fact that the interlock system was desattivated, the activation o fthe pressurerelief valve did not triggered any automatic action.
When later the iternlock was re-activated, teh accidental release of hydrogen into the compressor room triggered the shutdown of the facility.

A road accident causing a heavy duty vehicle to roll-over is a regularly reported event. Several administrations and also international global technical regulations require on the type-approval of a vehicle to pass a roll-over tests without major consequence. In this incident, the protections provided to the on-board pressure control system were inadequate to protect it from mechanical impact coming from a roll-over. Nevertheless, this incident occurred in the years 60’s, when the return of experience from this type of incidents could not have been developed yet. On the contrary, It is probable that the collection of these incidents contributed to the development of a better safety design.