Hundreds of passengers' lives were endangered after an Interislander ferry lost engine power while sailing the Cook Strait. Now a report has found the safety-critical rubber component of the ferry that failed was 18 years old, and two months overdue for a replacement.
The report's commissioner found KiwiRail, the owner of Interislander, ignored manufacturer advice.
On the night of January 28, nearly 900 passengers aboard the ferry Kaitaki were sent drifting towards the rocky coastline just off Wellington's south coast.
An emergency was declared around 5pm when a power outage hit and passengers put on life jackets as wind gusts and swells up to a metre high pushed the ship. It wasn't until four hours later the passengers made it safely to dry land.
The breakdown sparked an inquiry by the Transport Accident Investigation Commission into what went wrong and a preliminary report has been released on Friday.
When the Kaitaki was near Sinclair Head the shaft generator tripped and the vessel lost all electrical and propulsive power. The vessel's power system immediately switched to one of the auxiliary engines that was on standby,
The report found at about the same time an old rubber expansion joint (REJ) ruptured, causing the ship's high-temperature cooling water system to fail, flooding the engine room's bilge system before the crew could stop it.
The loss of water pressure from the cooling system meant the main engines could not be restarted safely and as a result, propulsion could not be restored in a timely manner
The Commission revealed the REJ that ruptured was two months overdue for replacement when it failed.
The part was 13 years old when installed in 2018 and 18 years old by the time it broke.
According to the Commission, the REJ should not have been older than eight months when installed and inspected annually and replaced after five years.
"They should be taken out of service before their natural ageing process puts them at unacceptable risk of failure," TAIC chief investigator of accidents Naveen Kozhuppakalam said in a statement.
"This happened because KiwiRail had not followed the manufacturer's advice; even under KiwiRail's own system, the REJ was two months overdue for replacement."
TAIC said since the incident, KiwiRail has updated its guidance for REJs, but it still doesn't comply with the manufacturer’s guidance and doesn't account for the date of manufacture.
"The Commission is concerned that similar safety critical components in the KiwiRail Interislander fleet may be at risk of failure if their dates of manufacture have not been accounted for in the replacement schedule," the report said.
Kozhuppakalam recommended that Maritime New Zealand require KiwiRail to provide evidence that safety-critical rubber expansion joints on the Interislander fleet are fit for purpose, taking into account the manufacturer’s guidance, and alert operators of ships of the guidance.
KiwiRail has apologised for the failure, saying it has taken a number of steps to ensure it never happens again.
"This was a serious event, and we are deeply sorry for any distress it caused to our passengers and crew," KiwiRail chief executive Peter Reidy said in a statement.
"Safety is Interislander’s top priority. I am proud of how our crew responded, in an extremely stressful situation and in line with all our training, to keep passengers safe and get the ship back to port as quickly as possible."
Since the incident, KiwiRail inspected all rubber joints across the entire fleet and replaced all safety-critical rubber expansion joints on Kaitaki and the rest of the fleet as a precaution. All critical equipment on its ferries were also audited.
"Our message to passengers, staff and customers is clear: Our ships are safe and we are closely monitoring all the safety-critical equipment on our vessels."
TAIC will issue a final report at the completion of the inquiry.
