Hydrogen Explosion from a Truck
An open backed truck was delivering various industrial gases to sites. At the site of the explosion a rack of argon gas bottles was being delivered to a laboratory in the building adjacent to the truck. The small lifting arm at the back of the truck was being used to offload the argon gas bottles when the operator (truck driver) heard a hissing sound. The operator stopped what he was doing and went to investigate the source of the sound at which point an explosion took place. The official accident investigation is not available, but the scientific article referred among the sources (Venetsanos et al.) report that according to that report the release was the result of two broken connections between pressure vessels adjacent to 6 mm diameter T-connection outlets from the cylinders. Shut-off valves were not used to secure the individual cylinders in the rack. The hydrogen ignited and exploded with an over-pressure of 5 kPa experienced at a distance of 90 m from the center of the explosion.The official investigation estimated that an over-pressure of 5 kPa (50 mbar) was experienced at a distance of 90m from the center of the explosion, based on the damage caused by the explosion.
Event Date
March 3, 1983
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Cause Comments
Immediate cause was the failure of connections between cylinders.The root cause is unknown, but a contributing cause appears to be a design shortcoming (material choice, safety design not considering individual shut-off valves).
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
Industrial pressure vessels, trailer, city buildings
Storage/Process Medium
Storage/Process Quantity
13
Actual Pressure
200
Design Pressure
200
Location Type
Location description
Inhabited Area
Operational Condition
Pre-event Summary
An open backed truck was delivering various industrial gases to sites in the Stockholm area. The truck was loaded with approximately 180Nm3 of hydrogen was stored in a rack of 18 interconnected 50 l industrial pressure vessels at 200 bar working pressure. The buildings in the area of the accident were typical of the center of a city, primarily residential, with approximately 56 floors. The closest building to the explosion was an office block of similar height to the neighboring buildings. The cross-sectional dimensions of road was approximately 2 m wide pavements on either side of a 10 m wide carriageway. Parking was permitted on both sides of the street.
Post-event Summary
40 kg of hydrogen were released.
Lessons Learned
Lessons Learned
It is not known if the official investigation report issued recommendations or legal requirements. nevertheless, regular inspection procedure should be in place to monitor high-pressure connections degradation, and shut-off valves should be used to control release from the individual cylinders in the rack. These recommendations are in line with the lesson learned of similar accidents.
Event Nature
Emergency Action
Unknown
Release Type
Release Substance
Hydrogen Release Concentration (%)
100.00
Release Amount (kg)
13.50
Release Pressure (bar)
200.00
Ignition Source
Ignition Delay (s)
10
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Flame Type
Source Category
References
References
A.G. Venetsanos et al.
Source, dispersion and combustion modelling of an accidental release of hydrogen in an urban environment
Journal of Hazardous Materials A105 (2003) 1–25