Roll-over of a CGH2 trailer

An accident involving a truck transporting hazardous goods occurred on a national road. Three buildings were evacuated and three people were slightly injured.
The road accident involved two cars and a truck transporting compressed hydrogen bottles. The truck overturned and ended up on its side on the road. No released occurred. The bottles were almost empty but still contained 10% hydrogen.
The firefighter blocked the traffic in both direction, evacuated three buildings and proceeded to release the remaining hydrogen, an operation which required a period of 1.5 hours. The bottles could then be dismantled one by one and transported away. Due to the special configuration and the interconnecting pipes, the firefighters took several hours to unload the whole truck.

INITIATING CAUSE was a traffic accident.
In absence of information on driver, the ROOT CAUSE is attributed generically to a human error (wrong manoeuvre).

cylinders

DESCRIPTION OF THE UNIT
The load consisted on ten pallets containing approximately 40 hydrogen bottles. From the photos the bottles appear to be standard bottles with a volume of 50 l and a pressure of 200 bar. If correct, the maximal load would result less than 300 kg. Since the bottles contained only 10% of their nominal value, the total quantity released was 30 kg.

Three car occupants were slightly injured and taken to hospital by the emergency services for medical treatment. The truck driver survived the accident unharmed.

Despite the roll-over, the structure of the pallets was enough robust to survive the mechanical stress and protect the connecting pipe system.