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Clean Hydrogen Partnership

CGH2 tube trailer leaking

Event

Event ID
1252
Quality
Description

The driver of a hydrogen tube trailer stopped for a rest break and heard an audible leak from the composite tubes module mounted on the trailer.
Local Fire department, local emergency services and the police responded. They established an 800-ft (250 m) evacuation area for several hours.
A technician of the shipping company responded and inspected on scene. The leak ceased without ignition (unclear if stopped by itself, or because of a manual intervantion).
Later, the unit was returned to shipping company's facility, where it was emptied, inspected by tubes manufacturer and later sent to manufacturer plant for repair.

Event Initiating system
Classification of the physical effects
Unignited Hydrogen Release
Nature of the consequences
leak no ignition
Macro-region
North America
Country
United States
Date
Component involved
joint/connection (neck)
Failure mode
leak, no ignition
Initiating cause
unknown
Root causes
Unknown
Date entry in HIAD
30/12/2025

Facility

Application
Hydrogen transport and distribution
Sub-application
CGH2 tube trailer
Hydrogen supply chain stage
Process temperature range [C]
ambient temperature (-50°C to +50°C)
Process pressure range [MPa]
medium to high pressure (10 to 50 MPa)
Location type
Open
Location
populated area
Operational condition
Pre-event occurrences

The PHMSA reports that the starting point of the journey was a metal component manufacturer, the destination was a hydrogen producer. Based on this, it appears that the trip was probably a return trip. However, the trailer was still transporting more than half of the nominal capacity. If the starting and the arriving points would be swapped, the trip would make more sense.

Description of the facility/unit/process/substances

Trailer technical specification (in SI):
Nominal pressure = 275 bar
Total capacity = 1,156 kg
Configuration = 8 tubes, organised in 2x2 plus 2x2 arrays

For one single tube:
Nominal content of one tube= 135 kg
Content in one tube before leak = 87 kg
Content in one tube after leak = 66 kg

Emergency & Consequences

Number of fatalities
0
Number of injured persons
0
Post-event summary

A limited amount og hydrogen was lost.

Lesson Learnt

Corrective Measures

According to PHMSA report, pending manufacturer’s findings, the hydrogen supplier will:
(1) maintain clear en-route leak-response protocols;
(2) evaluate a brief post-pickup observation and targeted leak check where practical;
(3) review the pre-trip checklist to capture pressure/valve status and consider a first-stop pressure confirmation;
(4) coordinate with the tanks manufacturer on any inspection and apply recommended checks as appropriate;
(5) submit a supplemental PHMSA incident form if the final inspection identifies a specific failure/cause or changes the reported facts.

In-depth data

Release type
gas
Involved substances (% vol)
H2 100%
Released amount (kg)
21
Release temperature [°C]
25
Release pressure [MPa]
27.5
Probable IGNITION SOURCE

References

Sources categories
PHMSA
Reference & weblink

Incident I-2025100048 of the US Pipeline and Hazardous Materials Safety Administration PHMSA:
https://portal.phmsa.dot.gov/analytics/saw.dll?Portalpages&PortalPath=%…
(accessed September 2024)