The Transport Accident Investigation Commission has released its final report into the grounding of the Interislander ferry Aratere near Picton, and it lands firmly on a poorly managed steering upgrade and an almost complete lack of crew training as the reasons the ship ended up on the rocks.
The Aratere ran aground on the evening of 21 June 2024, only minutes after leaving Picton on a scheduled Cook Strait crossing. There were 47 passengers and crew on board. No one was injured and the ship was refloated within about a day, but the grounding closed part of the harbour entrance and revived long-running concerns about the reliability of the ageing Interislander fleet.
The commission found the trouble started with the autopilot. As the ferry left the harbour the master engaged the system expecting a minor 3 degree course correction. The ship had already passed the waypoint that the correction related to, so instead of nudging the bow a few degrees the autopilot locked onto the next programmed turn, a far larger 34 degree swing to starboard. The bow began tracking towards the shore, and when the bridge team realised the turn was much bigger than they wanted and moved to take manual control, they could not get it back in time. The final report records that the ship grounded soon after.
The reason the crew could not simply grab the wheel sits at the centre of the report. In the period before the grounding Interislander had fitted the Aratere with a new Kongsberg steering system. The system it replaced let control pass freely between the consoles on the bridge. The new one would only transfer control between consoles once the rudder commands on each were aligned within 2 degrees of one another. The old system had no such requirement. There was a way around it, a force take-over function that handed control over regardless of alignment if a crew member held a button for five seconds, but as 1News reported, neither the bridge team nor the managers on shore knew that function was there.
The crew had never been trained on either point. Investigators found that training on the new system came down to an informal five-minute handover from a technician to a master during sea trials. The two differences that mattered most on the night, the alignment rule and the force take-over, were never passed on. Had the crew understood how to align the controls and use the override, the report concluded, “it is very likely they would have been successful in establishing immediate control” and the grounding would not have happened.
The commission’s chief investigator of accidents, Louise Cook, said the gap was serious enough to justify almost two years of investigation. “Interislander had treated the replacement steering system as a like-for-like change, without identifying important operational differences before returning the ship to service,” she said.
Cook said the wider lesson reached well beyond one ferry. “Any organisation introducing new safety-critical equipment needs to ask not just whether the system works, but how it changes the way people operate,” she said. “The human and operational side of change management is critical to safety.”
The report also set out failures in how the upgrade project was run. No single person held overall accountability for the work from start to finish, and the safety audit and assurance checks that should have caught the gaps were not carried out properly. That left managers on shore without a clear picture of what was happening on the bridge. The commission also noted that long-standing familiarity among the crew may have made people less willing to question pre-departure routines that fell short. In its media release the commission framed the grounding as a warning about upgrades that focus on getting the hardware installed while overlooking how the change affects the people who have to use it.
Despite the long list of findings, the commission made no formal recommendations. It said Interislander had already done the work needed to address the safety issues raised during the investigation. The operator has since rewritten its bridge resource management training, updated its navigation assessments, sharpened its change management process and produced ship-specific steering guidance. Independent assessors now carry out on-board bridge checks across the fleet, and the commission said it was satisfied those steps closed the gaps.
The Cook Strait ferries remain one of the country’s most important transport links, carrying passengers, freight and rail wagons between the two main islands, and their reliability has been under steady scrutiny as the fleet ages and the government works through its long-delayed replacement plan. The Aratere report is a reminder that the risks are not only mechanical. The commission’s central point is that a new piece of equipment is only as safe as the training and oversight that come with it. More detail on the investigation is available from the Transport Accident Investigation Commission.
What do you make of the findings? Have you sailed on the Aratere or the other Cook Strait ferries, and does the report change how you feel about them? Share your thoughts in the comments below.
This article was written by AI, briefed to report the facts, hopefully without some of the bias people bring to the job π
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