Incident Synopsis
During transfer of liquid H2 from a commercial tank trailer to a receiving vessel, a leak developed in a bayonet fitting at the trailer/facility connection. The leak produced liquid H2 spray which enveloped the rear of the truck where the hand-operated shutoff valve was located. Emergency trained personnel, wearing protective clothing, except for proper shoes, entered the area and shut off the flow control valve. Reentry personnel suffered frost bite of their feet when shoes became frozen to the water-wetted rear deck of the truck.

A loose hose flange connection allowed leakage of cold fluid through the lubricated bayonet seal. This allowed cold fluid to contact and shrink the 'O' ring seal (made of Buna-N rubber), thus permitting liquid hydrogen leakage to the atmosphere.

Incident Date
Dec 31, 1969
  • Piping/Fittings/Valves
  • Valve
  • Vehicle & Fueling Systems
  • Liquid Hydrogen Delivery Vehicle
Damage and Injuries
Probable Cause
When Incident Discovered
Lessons Learned

All tank trailers should have a safely accessible auxiliary shut off valve in case of spills.
Emergency personnel need to have access to all of the appropriate protective clothing, including shoes. Liquid hydrogen is stored at 20.28 Kelvin or -423.166 °F, and is cold enough to freeze surrounding air at these temperatures.