Roll-over of a CGH2 tube trailer

This incident consisted in the accidental release of a CGH2 tube trailer after that it had rolled sideward on the ground.

A hydrogen delivery company driver arrived at the customer site to investigate a reported leaking valve on a hydrogen trailer. The driver arrived with a full trailer in the event that the leaking valve could not be repaired on the spot.
After confirming the leak, the driver decided to swap the trailers. The new trailer had just been lowered on its landing gear and separated from the tractor, when the ground gave away, causing the trailer to roll on its side.
The stainless steel vent stacks on the top of the trailer were pushed up when they impacted the ground. As a result, six valves were immediately sheared off, and their contents began to vent. The entire contents of the six tubes vented within about 90 seconds.
No flames were observed and no secondary damage indicated the presence of flames.
The local emergency services and the hydrogen company experts decided to let all the 6 leaking tubes venting and proceeded to vent manually the other tubes still intact, till the whole load was released to the atmosphere.

The INITIATING CAUSE was the roll-over of the trailer because positioned on weak ground. An independent CONTRIBUING CAUSE preceding the initiating one, was the need to swap trailers due to the leaking of a valve on the previously installed trailer.

The driver has made many trips to the plant without incident and had no reason to believe that the roadway would not bear the weight of the trailer. The landing gear could have been secured by timbers or support plates in order to prevent them from sinking in the ground.
The ROOT CAUSE could be combination of lack of proper location for the delivery of trailers at the customer location and the lack of a precautions aiming at guaranteeing supporting ground.

valve

The leak of a valve on the already installed trailer preceded this incident, causing the hydrogen delivery company to swap trailers.

The customer was a gas fired power plant. It can be assumed that the use of hydrogen was as coolant of the generator.

Material Loss: $ 2,282.00
Carrier Damage: $ 25,000.00

The driver pulled the tractor away from the rolled trailer and called the emergency service. The fire department arrived and the immediate evacuation of the plant upwind was ordered. The hydrogen company specialists arrived approximately two hours after the start of the incident. They assessed the situation and concluded that the remaining full tubes could be safely vented before attempting to right the trailer. A vent hose was assembled and each tube was slowly vented. Approximately 9 hours later the tubes were empty and the company crane began recovery. Once up-righted, the condition of the trailer was assessed and no damage to lights, brakes, or suspension system was observed. It was concluded that the trailer could be safely moved away.

This incident regards the roll-over of a heavy trailer because positioned on weak ground.
The roll-over could have been avoided, if at least one of the following three options would have been in place: (i) if a procedure would have required the driver to check the quality of the ground before placing the trailer; (ii) if the customer would have carefully checked the location and prepared and/or indicated the areas to be used for parking the trailer, (iii) if the customer had guaranteed the correct ground resistance.