Gas leak that held up ferries and cruise ship discovered hours earlier

A gas leak which held up two ferries and a cruise ship was noticed hours earlier during a Cook Strait crossing.

Interislander workers could “faintly smell” LPG during a cargo check of the Wellington to Picton dangerous goods sailing, but the source of the “minor leak” could not be picked up by automatic detection sensors or staff using hand-held detectors.

A KiwiRail spokesman said this was because the leak was “very small” and behind an enclosed cabinet.

The ferry docked in Picton about 2am on January 24, and the shunt crew were advised of a “possible leak” coming from one of eight 25,000 litre tankers on a rail consignment, the spokesman said.

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“In the rail yard, the leak continued to be difficult to identify,” he said.

Hourly visual inspections were undertaken over the next four hours, but the leak was not located until the site manager arrived about 6am.

By this time, the leak could be heard and smelled, so an exclusion zone of 200m was established, staff were evacuated, commercial vehicles were diverted, port security were notified, and Fire and Emergency New Zealand was requested.

LPG in its natural state is odourless, so a specific odour is added to ensure people can smell leaks.

The odour is targeted to the human smell sense and thus can be detected at a much lower level than equipment usually detects.

Following the January incident, KiwiRail installed sensitive Active Gas Detection units, specifically configured for LPG, at the Picton and Wellington ferry terminals. One would also be carried on board the Interislander.

According to Fire and Emergency’s operational review of the incident, the leak was coming from a locked box on the end of the tank, which neither KiwiRail nor FENZ could access.

As Genesis Energy, which owned the tank, scrambled to find a technician to respond to the leak, initially getting one to start driving from Christchurch, pressure was mounting from the port.

The shutdown was affecting the berthing of another ferry and a cruise liner, the operational review said.

About 7am, cars waiting to board the ferry were left in place, as the people were removed.

By 8.20am, a Marlborough electrician was at the scene and worked with emergency responders to open the locked box on the LPG tank.

The electrician found a partially opened valve, which was able to be closed, the FENZ review said.

Port operations resumed just before 10am.

According to the operational review, the incident was “only a minor gas leak”, but caused significant disruption to freight and passenger transport.

The tactical approach to the management of the incident was modelled on the learnings from a previous “much larger incident” and was appropriate, although cautious, the review said.

An interagency management team was not formed, although an ad hoc version did eventuate.

The lack of an interagency team, where information could be readily shared, caused some confusion between affected agencies, especially over decisions such as the management of shipping, the review noted.

There was also difficulty in arranging for a contractor from the LPG company, although one was eventually sourced locally and when this person assessed the situation, the incident was resolved swiftly.

The review concluded the incident was managed with appropriate tactics however; the conclusion was hampered by a lack of a timely response of industry experts,