An incident where an Interislander ferry lost power in the Cook Strait almost certainly would have ended in a serious casualty if not for a well-timed anchor drop, a report says.
An investigation into the dramatic Kaitaki breakdown in 2023 has also shown the response to the emergency was poorly structured and the co-ordination between stakeholders during the rescue was lacking.
The Transport Accident Investigation Commission (TAIC) today released its final report into the maritime incident, concluding the multi-year inquiry.
KiwiRail was fined more than $400,000 for the mayday incident, which took place three years ago.
At 4.55pm on January 28, 2023, the operator advised Maritime New Zealand the Kaitaki ferry had reported engine problems.
The ferry lost power in the middle of the Cook Strait and drifted for an hour with 864 people on board.
“Time was critical, and if the ship had not been arrested by its anchors, a very serious marine casualty was virtually certain,” the report stated.
The inquiry found the ship’s master and bridge team responded appropriately but a “more structured” and “well-exercised” engineer’s response would have likely resolved the mechanical failure sooner.
“An engineer aboard described the scene as ‘organised chaos, everybody was everywhere trying to do everything’,” the report stated.
“The attempts may have been successful sooner if the response had been more structured and focussed on stabilising the systems necessary to operate the auxiliary engine, restore power and then attempt to restore main propulsion.”
TAIC found that although it was clear the Rescue Coordination Centre New Zealand (RCCNZ) was leading the rescue operation, there was “a lack of common understanding and coordination among the various stakeholders”.
TAIC chief commissioner David Clarke said the Interislander had conducted some drills with RCCNZ but these were limited and did not fully test how organisations would work together in a real emergency.
On the day of the event, the wind was blowing about 30 knots, with gusts of 45 knots, and the swell was about 3m when the ship’s master put out a mayday call and began preparing a full evacuation, dropping two anchors as soon as possible.
Before the anchors took hold, the vessel was drifting at such a rate they only had about 12 minutes until they reached dangerously shallow waters.
The engineering team leapt to action, replacing a high temperature (HT) outlet compensator on the vessel’s diesel generator, which had failed and caused the ship’s cooling water to drain into the bilges.
Once the compensator had been replaced and cooling water system refilled, power was restored, the ferry picked up its anchors, and continued to Wellington without further incident.
A preliminary report from TAIC in May 2023 revealed the faulty compensator was a piece of safety-critical equipment that was 13 years older than it should have been.
TAIC recommended KiwiRail review its emergency response planning, training, resourcing and risk mitigations to make sure they could effectively respond to a maritime emergency.
It also recommended KiwiRail “effectively implement the decision-support system for its vessels’ engineering departments” and regularly familiarise crew with it.
TAIC made three recommendations to Maritime New Zealand.
It “strongly encouraged” all passenger ferry operators to conduct and review escape, evacuation and rescue analyses, regardless of when the vessel was built.
TAIC wanted Maritime New Zealand to review its maritime incident readiness and response strategy, which needed to include a specific Cook Strait plan.
It also recommended Maritime New Zealand, the Ministry of Transport and other stakeholders implement a wider response strategy that would identify areas most susceptible to maritime casualties.
Maritime New Zealand said in a statement the “blackout event” was a “close call” and would have been “traumatising” for passengers onboard the Kaitaki.
“As soon as the MAYDAY call was relayed, [RCCNZ] initiated the mass rescue plan as intended.”
Maritime New Zealand only fully agreed with two of TAIC’s recommendations.
“We only partially accept the recommendation on strengthening salvage and rescue capability.
“While we can, and do, highlight what capabilities are needed for response in New Zealand, ensuring the resourcing of emergency towage response capability is not something in our power to make happen,” Maritime New Zealand director Kirstie Hewlett said.
It admitted a maritime incident response team (MIRT), which is a “back-office function”, should have been formally declared from the outset of the incident.
“However, we believe the commission’s finding that the lack of a formal MIRT declaration would have adversely affected our ability to respond promptly had the situation escalated, misses the pulling together of key facts,” Hewlett said.
She said while the MIRT was not formally declared, its necessary functions were mobilised and in operation until the ferry was in port.
KiwiRail, which operated the Interislander ferry, was sentenced in the Wellington District Court in 2024 for exposing passengers and crew to harm. KiwiRail was fined $412,500 for the dramatic event.
Harrowing passenger accounts of the incident were read out at the sentencing.
Sobbing passengers filmed final farewells to loved ones as the Kaitaki drifted, powerless, towards the rocky shore, the court heard.
The chaos and fear on board the vessel – including people crying, vomiting, and having panic attacks – were described in victim impact statements.
KiwiRail’s executive general manager for the Interislander, Duncan Roy, read a statement in court apologising for the incident.
“This was not a situation that anyone should have had to experience,” he said.
“KiwiRail takes this event very seriously and I take this event very seriously. KiwiRail’s guilty plea is an acknowledgment of the failures that led to this event.”
A compensator is a flexible rubber component designed to connect rigid piping systems which carry fluids, slurries or gases under pressure or vacuum at varying temperatures. They are used to dampen the effects of vibration on the rigid piping.
On the Kaitaki, compensators were used to connect the piping system which carried the HT cooling water around all the main engines and diesel generators on the vessel.
One of the compensators failed, causing the majority of the HT cooling water to drain out and the entire HT cooling system to lose pressure. This resulted in all the vessel’s main engines shutting down to prevent them from suffering “catastrophic damage”.
The failure had been identified as a significant risk in a 2007 report, which also noted this exact fault had happened twice before on the Kaitaki when it was operating in Northern Europe.
Kaitaki was known to suffer from higher than normal levels of vibration within machinery spaces, which negatively affects various system components.
The report recommended the compensators be replaced every two years, regardless of their condition.
Just a few months after the report was received, Kaitaki suffered the same compensator failure while the ferry was berthed in Wellington. The chief engineer noted at the time the compensators were generally replaced every four or five years.
The compensator which caused the 2023 failure had been in use for five years and eight months. The manufacturer’s stamp also showed it was 18 years old when it failed.
Janhavi Gosavi is a Wellington-based journalist for the New Zealand Herald who covers news in the capital.