Road incident with Tube Trailer
This accident happened on the SS66 road and involved a trailer transporting compressed hydrogen cylinders. The 50 l cylinders were in packages of 16 cylinders each. Due to the breaking of fixing straps, cylinder packages fell on the middle of the road.The damage to the gas collector of the package and to some cylinders valves caused a gas release with consequent deflagration, with consequent damage to the first vehicle following the truck and to the glass door of house in the vicinity
Event Date
December 23, 2003
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
Breaking or losing of the fixing strap caused falling of one or more H2 cylinder packages.Damage to some the cylinder heads cased release and consequent ignition.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
Truck, cylinders rack
Storage/Process Medium
Actual Pressure
200
Location Type
Location description
Inhabited Area
Operational Condition
Pre-event Summary
compressed hydrogen truck traveling on a road with house in the vicinity. Each package had a capacity of approx. 12 Kg. Assuming that they were all full, full damage to one package would have released the total quantity. it is however not possible to deduce from the photo how many cylinder valves failed.
Currency
Lessons Learned
Lessons Learned
The analysis of this accident has revealed the followings critical points which shall be used as recommendations: 1. Lack of a system indicating the pressure inside the cylinders. The knowledge of the pressure is critical for the formulation of the correct rescue procedures.2. Lack of a system visualizing/confirming that all the cylinder valves are closed.All valves should be closed during transport. If however a valve was forgotten open, a damage to the gas collector will be enough to release the whole content of that cylinder.3. The package design doesn't offer the structural resistance required to protect the cylinders in case of fall-off the trucks.
Event Nature
Emergency Action
The fire brigade cooled the cylinders with by nebulized water. At the same time, they evacuated two persons that were working in the vicinity and closed the road to the traffic. A thermal camera allowed to assess the temperature of the cylinders, therefore assisting the cooling of the hot spots. The last operation was the emptying of the of the cylinders under jets of nebulized water.
Release Type
Release Substance
Hydrogen Release Concentration (%)
100.00
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Flame Length (m)
1.00
Source Category
References
References
Article presented at the Int. Conference on Hydrogen Safety ICHS2005 Available at: http://conference.ing.unipi.it/ichs2005/Papers/230001.pdf (accessed June 2020)