collision of a truck carrying Hydrogen cylinders

On a highway, a truck loaded with 400 gas cylinders crashed at night for an undetermined cause against a concrete wall and overturned. It slipped 150 m, before several 200 litre cylinders of hydrogen caught fire and set the truck on fire as well. The police stated that it was “a large fire with detonations”. The 400 gas cylinders were connected together and many of the cylinders had fallen out of their racks.
In order to reduce the danger of further explosions, the fire-brigade cooled the gas cylinders with water for two hours.
The highway remained closed for eight hours.
The driver cabin burned completely. The damage was estimated at 200,000 Euros, not including the damage to the tarmac. The truck driver was taken to hospital with heavy injuries.

The INITIATING CAUSE was a road crash.

Nothing is reported on the state of health of the drivers, or on possible environmental factors which could have contributed to the crash.

Therefore, in absence of details, the ROOT CAUSE can be attributed to a human error which brought to a loss of control of the vehicle. An important factor which probably contributed to escalation was that all the cyinders were all connected together.

gas cylinders

Assuming that all the 200 l cylinders were completely filled at 20 MPa, the truck was carrying a non-credible amount of hydrogen, possible only if it were in liquid form. From the picutre, the cylinders appear standard 50 l, 20 Mpa bottles, corresponding to 290 kg of H2.

The driver was brought to the hospital.

The source does not report any lesson learnt. The fact that the cylinders were all connected to each other made possible a release of the whole load at once. This is a scenario which should be avoided during transport. A corrective design measure could be the creation of subsystems, each provided with proper pressure control (e.g. shut-off valves to be closed during when travelling).