Interislander ferry reliability improves, but still below target

The on-time performance and reliability of Interislander’s ferries have improved in the past financial year but still fall short of KiwiRail targets.

The improvement comes after what was described as a “horror run” in the previous financial year that was by far the worst for Interislander services in recent times.

KiwiRail has published the ferries’ latest performance results in its 2023 annual report.

On-time performance has improved to 83 per cent of ferries arriving within 15 minutes of their scheduled time.

This is a 10 per cent increase compared to the previous year, although still short of the 88 per cent target.

The annual report said this was a positive result given the serious disruption to services following an engine issue with Kaitaki and reflected the “hard work of the team”.

Kaitaki issued a mayday call in January when all four engines shut down in the middle of a roaring southerly in Cook Strait with 864 people aboard.

The vessel narrowly avoided disaster but was effectively out of action for two months after this incident as well as because of a separate problem with its gearbox.

“A Kaitaki gearbox failure saw the ship taken out of service for an extended period while repairs were undertaken,” the report said.

“These challenges led to sailing cancellations, which dampened the rebound in passenger and freight revenue from the return to service of Kaiarahi in September 2022 and the return of international tourists as the impact of Covid lessened.”

KiwiRail's Interislander ferries. Photo / Mark Mitchell

Kaiarahi returned in September 2022 after being out of service for an entire year due to its gearbox suffering catastrophic damage.

Despite this, the annual report showed ferry reliability has also improved after one in five sailings were cancelled in the 2022 reporting year.

Reliability is now up to 87 per cent, but still well below the target of 98 per cent.

The report acknowledged Interislander had faced significant disruption as a consequence of mechanical issues and weather events.

“KiwiRail is focused on lifting reliability and on-time performance for our customers, through increasing resiliency of critical frontline roles, enhanced inspection and maintenance programmes, and system improvements.”

There has also been an increased focus on maintenance, the report said. KiwiRail put $42 million in capital expenditure towards the maintenance of its ageing ships, as well as systems for two new mega-ferries due to arrive in 2025 and 2026.

“Our entire asset management regime for Interislander has been updated to include more detailed tracking, more frequent inspections of safety-critical equipment, and global benchmarking to ensure the ferries continue to sail safely and efficiently for New Zealand,” the report said.

Interislander fleet operations transformation manager Taru Sawhney said they have always had rigorous processes for ensuring ships are safe and their service is reliable.

The improvement this year comes as Interislander takes steps over and above what is required to enhance the reliability of the ageing fleet until the new ferries arrive, Sawhney said.

“This includes additional scheduled maintenance periods for each ferry where they are taken out of service. They’re also taken out for longer periods in either a wet or dry dock environment for a more comprehensive maintenance programme.

“We continue to take a safety-first approach, which means we will not sail ships unless we are satisfied it is safe to do so. The safety of our passengers and employees is always the top priority for our Interislander crews and determines operational decisions.”

Georgina Campbell is a Wellington-based reporter who has a particular interest in local government, transport, and seismic issues. She joined the Herald in 2019 after working as a broadcast journalist.