KiwiRail charged over Interislander Kaitaki ferry breakdown

KiwiRail has been charged in relation to the breakdown of a ferry with hundreds of passengers on board a year ago. 

Now, Maritime NZ has filed one charge against KiwiRail, the ferry's operator, under the Health and Safety at Work Act 2015.

In January 2023, the Interislander's largest ferry - the Kaitaki - lost engine power while sailing the Cook Strait with 800 passengers and 80 crew aboard. It issued a mayday call as wind gusts and swells up to a metre high pushed the ship towards the rocky coastline. 

It activated a major emergency operation on the South Coast in case passengers had to abandon the ship. 

The rescue plan included the Harbourmaster, Police, NZ Defence Force, KiwiRail, rescue helicopter organisations, ambulance services and other emergency services. About 25 vehicles and drivers from the local four-wheel-drive club were also sent to the Red Rocks carpark, the only vehicles that could get rescuers close enough in the rugged terrain. 

After the boat finally restored some of its engine power, it made its way back to Wellington, escorted by the two harbour tugs. Four hours after the power loss the passengers made it safely to dry land. 

The breakdown sparked an inquiry by the Transport Accident Investigation Commission into what went wrong. It found a crucial, but ageing rubber expansion joint was to blame. 

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.

However, 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 meant the main engines could not be restarted safely and as a result, propulsion could not be restored in a timely manner.

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. 

The ruptured rubber expansion joint.
The ruptured rubber expansion joint. Photo credit: Transport Accident Investigation Commission

"The investigation took 12 months; it involved reviewing the operator's organisational information relevant to processes and procedures connected to safety and maintenance management, undertaking interviews and examining the Kaitaki after the incident occurred," Maritime NZ Director Kirstie Hewlett said. 

"Material was then comprehensively reviewed before the decision was made to prosecute." 

In response to Thursday's charge, KiwiRail chief executive Peter Reidy said the company assures all our passengers and staff that "their safety is and will always be our highest priority". 

"The safe and reliable operation of the Interislander service is an absolutely non-negotiable requirement for KiwiRail Board and management. Following the Kaitaki incident, we conducted a full review of all of our asset management practices, using global experts to ensure we are running the Interislander to world’s best practice standards," Reidy said, 

"We are pleased that over the recent busy Christmas period the Interislander ferries have operated with 100 per cent asset reliability and 91.4 per cent on-time performance. For comparison, these are levels matching even the best operators in the global aviation industry.  

As this matter is now before the Courts, Maritime NZ and KiwiRail will not be making any further comments.