TAIC final report on the 2023 Kaitaki blackout finds 864 lives were nearly lost to a single rubber joint that was 18 years old
The Transport Accident Investigation Commission has released its final report into the Interislander ferry Kaitaki blackout in Cook Strait on 28 January 2023, finding that 864 lives were placed at serious risk by the failure of a single rubber expansion joint that was nearly two decades old and overdue for replacement by about sixteen years. The Commission concluded the incident was both foreseeable and preventable, and that only the timely deployment of the Kaitaki’s anchors stopped the vessel grounding on rocks near Sinclair Head, about a nautical mile off the Wellington south coast.
The Kaitaki had left Picton bound for Wellington in heavy southerly weather when the starboard shaft generator tripped and the ship lost power. Moments later, a rubber expansion joint on the port auxiliary engine ruptured, taking down the high-temperature cooling system that the four main engines need to run. The report described the consequence in plain terms, saying the loss of water pressure from the cooling system meant none of the four main engines could be restarted safely. The vessel drifted for about an hour. Engineers in the report described conditions in the engine room as organised chaos, with everybody trying to do everything at once.
Investigators traced the rupture to a rubber expansion joint that had been in service for at least five years and was around 18 years old. The manufacturer’s recommended replacement interval is two years. The report pulls together six systemic safety issues, including the deterioration of rubber expansion joints across the fleet, inadequate safety management processes at Interislander, insufficient risk management for the country’s ageing Cook Strait ferries, a thin towage and salvage capability in the strait, an absence of well-rehearsed maritime mass-rescue exercises, and duty controllers who lacked specialist maritime expertise and structured decision-support tools when the mayday came in. A summary of all six issues has been published alongside the report.
The Maritime Union of New Zealand reacted strongly. National Secretary Carl Findlay said how a single part, which was nearly two decades old and overdue for replacement, could almost cause a disaster is horrifying. Findlay said the union’s members were out there every day on these ships, along with passengers who had a right to expect modern developed-world standards. He used the report to renew his criticism of the cancellation of the iReX ferry replacement project, arguing that the decision had left the country dependent on an ageing fleet prone to technical failure. The union also raised concerns that savings made by cancelling an emergency tug contract had been redirected to other infrastructure rather than ploughed back into Cook Strait safety.
KiwiRail accepted responsibility for the failures identified by the Commission. In its formal response, the state-owned operator said the incident had prompted a comprehensive reassessment of Interislander ferry management and maintenance practices. KiwiRail says it has tightened replacement schedules for rubber expansion joints across the fleet, rebuilt its safety management documentation, and invested in extra training so engineers and bridge crews can work through a complete blackout drill in real conditions. Maritime NZ, which the Commission criticised for not having stood up a Maritime Incident Response Team in time, said it was working through the recommendations and would publish a more detailed reply, with strengthening response strategies, revising evacuation guidelines and giving duty controllers stronger access to specialist maritime advice as its short-term focus.
The Commission found that, before the anchors took hold, the Kaitaki had been drifting at a rate that would have put it in dangerously shallow water within about twelve minutes. The chief officer’s order to drop both anchors, an action the bridge team had only minutes to weigh up, almost certainly stopped the vessel running aground. Had the anchors not held, the report says the most likely outcome would have been a grounding on a falling tide in heavy seas, with hundreds of passengers and crew exposed to a difficult evacuation in conditions that would have stretched any rescue plan available to Maritime NZ at the time.
The TAIC findings are the latest in a string of unflattering Cook Strait outcomes. Just two days ago KiwiRail was fined $375,000 over the 2024 grounding of the Aratere in Picton Harbour, an incident Maritime NZ traced to a knowledge gap with a newly modified steering console. Together the two events sharpen the picture the Maritime Union has been painting for several years, that the country’s three Interislander ferries are old, fragile, and being asked to do more crossings than the maintenance regime can comfortably support.
For passengers and freight customers there is no immediate change to sailings. Interislander says the Kaitaki, the Aratere and the Kaiarahi are all running their published timetables, and that engineering inspections triggered after the 2023 blackout have already replaced the most at-risk parts on every vessel. The bigger questions are political. Replacement ferries are not expected before the end of the decade after the iReX rail-enabled ships were cancelled in 2023, and the procurement contest for a smaller, road-only replacement fleet is still under way. Until those new ships arrive the existing fleet will keep getting older, and reports like this one will keep landing.
Whether the Commission’s recommendations are enough to satisfy the union, the regulator and the travelling public will be tested every winter from here, when the southerly funnels into Cook Strait and a single component on a thirty-year-old hull stands between an everyday crossing and another mayday call.
What do you think, has the Commission gone far enough, or is the bigger fix replacing the ferries themselves? Tell us in the comments below.