World’s first LH2 carrier published accident report

The difficulties of shipping liquefied hydrogen have been highlighted in a new report from the Australian Transport Safety Bureau, which shows how a safety issue arose on the maiden voyage last year of the Susio Frontier, the world’s first and only liquefied hydrogen (LH2) carrier. 

The failure of an incorrectly-fitted electrical solenoid valve led to the brief propagation of flame from the vent stack of the gas combustion unit of the Suiso Frontier at the Port of Hastings in Victoria in January 2022.

After LH2 had been loaded at Hastings on January 24, the ship was still berthed on the evening of January 25 when the gas control equipment malfunction occurred.

A worker onboard the ship observed a yellow gas flame briefly propagate from the gas combustion unit’s vent stack on the ship’s deck. There was no subsequent fire or explosion, and no injuries or damage were reported.

An ATSB investigation found the gas combustion unit’s air fan discharge damper actuators – which regulate the flow of air into the unit – were fitted with direct current (DC) electrical solenoid valves, which were incompatible with the 230 V alternating current (AC) supply from the GCU control system.

In addition to the incorrect solenoid valve being fitted, the ATSB found the gas combustion unit was not equipped to detect the failure of the valve, nor the subsequent closing of the damper.

In response to the incident, the manufacturer of the gas combustion unit, Saacke, fitted limit switches on each air fan discharge damper to monitor damper position.

In addition, the system’s control logic has been programmed to stop the unit if a fault is detected.

LH2, which has to be frozen to minus 253 Celsius, is still in its infancy as a seaborne trade. Kawasaki Heavy Industries, the Japanese builder of the Susio Frontier, is working on larger ship designs as are a number of other Asian yards, while Eneos, Japan’s largest oil company, is working on a project whereby hydrogen could soon be shipped in regular oil tankers at ambient temperatures.