The six safety issues that stranded the Kaitaki in the Cook Strait

Source: Radio New Zealand

The Transport Accident Investigation Commission has outlined six major system failures in a report on the loss of power aboard the Interislander ferry Kaitaki in 2023.

The ship shut down and drifted for an hour, dangerously close to rocks near Wellington Harbour, with 864 people on board on 28 January, resulting in a mayday call.

According to the report, “a very serious marine casualty” was narrowly avoided.

In the months following the incident, a preliminary inquiry found an out of date safety-critical rubber expansion joint [REJ] ruptured and prevented the engines restarting.

According to this report: “When the Kaitaki was approximately one nautical mile off Sinclair Head, the starboard shaft generator tripped. As a result, the vessel suffered a blackout.”

“Shortly after, an REJ [rubber expansion joint] on the port auxiliary engine ruptured. This resulted in the loss of water from the high-temperature cooling water system, which provided cooling to all main and auxiliary engines.

“The loss of water pressure from the cooling system meant none of the four main engines could be restarted safely. As a result, propulsion could not be restored quickly.”

The preliminary report said the expansion joint installed in the engine’s high temperature water cooling system had been in service for at least five years and was nearly 18 years old when it failed. Interislander’s Failure Mode and Effects Analysis [FMEA] recommended these parts be replaced after two years of use.

The commission said safety action taken by Maritime NZ and KiwiRail in response to the preliminary report meant it did not issue any further recommendations relating to the findings of the preliminary report.

Today’s TAIC report highlighted six safety issues:

• The deterioration of rubber expansion joints;
• Interislander’s failure to implement safety management processes to assess and mitigate risks specific to the ships in their fleet;
• Management of risks associated with the ageing Cook Strait ferries which had not “kept pace” with increasing risks associated with their age and condition;
• A lack of sufficient and readily available towage and salvage capability;
• A lack continuous improvement and exercise of maritime mass rescue operations to ensure preparedness and co-ordination between emergency response agencies;
• Duty controllers’ without access to specialist maritime expertise and a lack of an adequate decision making processes to respond to maritime incidents.

KiwiRail, in a statement, said it accepted the report and welcomed the clarity it provided – and reiterated its commitment to safe Interislander operations.

‘Organised chaos’ on board

The report found the ship’s master and bridge team responded “appropriately and in a structured way” to the emergency.

However, “a more structured and well-exercised engineer’s response would have likely resolved the mechanical failure and returned propulsion sooner. This would have been critical had the ship’s anchors not arrested the drift towards the shore”.

According to the report: “An engineer on board described the scene as ‘organised chaos, everybody was everywhere trying to do everything’. Various crew members attempted to restart the main engines and the auxiliary engines.”

“A lack of communication further hampered the recovery efforts. When the first blackout occurred, several engineers were attempting to reset tripped circuit breakers by toggling them on and off. They were unaware that others were simultaneously trying to start the pumps locally, which required the circuit breakers to be on.

“Time was critical, and if the ship had not been arrested by its anchors, a very serious marine casualty was virtually certain.”

The report found the Kaitaki was not subject to International Maritime Organisation guidelines for evacuation capabilities, as it was constructed in 1995, before the mandatory compliance window.

However, following the guidelines would have been best practice for passenger safety, it said.

Interislander had conducted drills to assess preparedness for emergencies such as fires, abandon ship or man overboard, but they were done on “an ad hoc basis” and there appeared to be shortcomings against international standards.

The commission noted that since the incident Interislander had commissioned a second EERA [Emergency Evacuation Rescue Analysis] and created an Emergency Towing Booklet for the Kaitaki.

Recommendations

Today’s final TAIC report made five recommendations which were put to Maritime NZ and KiwiRail in March:

KiwiRail should:

• review their emergency response planning, training, resourcing and risk mitigation process to ensure effective response to a maritime emergency;
• implement decision-support systems for its vessels’ engineering departments.

Maritime NZ should:

• revise guidelines on evacuation analysis for new and existing passenger ships and conduct regular Escape, Evacuation and Rescue Analyses (EERAs);
• prioritise the review of its Maritime Incident Readiness and Response Strategy including specific Cook Strait response plans and an across agencies exercise programme;
• work with the Ministry of Transport and other stakeholders to continue to identify areas susceptible to “serious marine casualty, particularly mass fatality events” implement a wider maritime incident response strategy and strengthen the salvage and rescue capability.

The report noted that some of these recommendations would also require the involvement of Bluebridge ferries.

In response to the report, KiwiRail said it welcomed the clarity it provided on the causes of the incident and the safety lessons for the wider maritime sector.

KiwiRail had already accepted full responsibility in court under the Health and Safety at Work Act, and gave formal apologies to those impacted by the incident.

Chief operations officer Duncan Roy said the incident had prompted a comprehensive reassessment of how the company managed and maintained its ferries, and how crews were supported to respond in emergencies.

Since the incident, Interislander had strengthened emergency response training, introduced engineer-based emergency response simulation and training and expanded the scope and frequency of emergency exercises, including multi‑agency scenarios, to ensure crews were well prepared.

Interislander had undertaken a full review of its asset management practices, supported by global maritime experts to ensure world‑class standards, and actively monitored around 10,000 individual components across its vessels, as well as all critical onboard systems, “a level of detail and specificity that is unusual within the maritime industry”.

It had also established a Technical Advisory Group (TAG), made up of senior maritime experts, to provide oversight and advice.

Since returning to full service after the incident Kaitaki had made more than 3600 crossings of Cook Strait, and its reliability to sail over that period has been 99 percent (excluding weather).

The current Interislander fleet had been independently assessed by international maritime experts DNV, which found there are no systemic issues preventing the vessels from operating safely until at least 2029, “subject to enhanced levels of maintenance investment, which KiwiRail is committed to delivering”.

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– Published by EveningReport.nz and AsiaPacificReport.nz, see: MIL OSI in partnership with Radio New Zealand