Isle of Man Ship Registry to flag New Zealand’s diesel-electric ferries

The Isle of Man Ship Registry has been selected as the flag state to oversee the construction of two rail-enabled roll-on roll-off passenger ( RoPax) ferries that will connect New Zealand’s North and South Islands.

State-owned transport operator KiwiRail has ordered the future-proofed vessels to modernise its fleet of ferries serving the Cook Strait.

KiwiRail’s Interislander service connects New Zealand’s State Highway and national rail networks between the capital city Wellington in the North Island and Picton in the South Island. The Interislander carries approximately 850,000 passengers, 250,000 cars and up to NZ$14 billion worth of freight annually.

The search to find a preferred shipyard began last year when KiwiRail issued an expression of interest to international shipyards. The selection of a successful shipyard is due to be completed in the next few months.

KiwiRail has now appointed the Isle of Man Ship Registry as the newbuildings’ flag. The ship registry will work in partnership with KiwiRail’s chosen classification society, overseeing the build process once a shipyard has been confirmed.

The two 220-metre RoPax ferries, which are being designed by Denmark’s OSK-ShipTech, will each be capable of carrying about 1,900 passengers.

They will also have a capacity of approximately 3,600 lane metres, allowing them to transport a combination of vehicles including up to 40 sixty-foot rail wagons.

The new ferries will trigger significant changes to the Wellington and Waitohi Picton waterfronts, including new ferry berths, terminals and both rail and road connections to ensure the benefits of the new ferries are fully realised. The ships are targeted to enter service in the mid-2020s, replacing the existing three-vessel Interislander fleet.

“As these two sister vessels will be carrying passengers, cars, freight and rolling stock, they will be quite flexible in their capabilities. They will need to be able to turn-around in 60 minutes at peak times, so will have a dual-capability linkspan to allow rail freight and vehicles to load and unload at the same time,” Chris Martin, a Senior Surveyor at the Isle of Man Ship Registry, commented.

“The ferries will also have to comply with quite stringent wave energy rules required for speeds in excess of 15 knots in the Marlborough Sounds, at the northern end of the South Island. This will require a very efficient hull form that must also have excellent seakeeping properties to deal with the often-challenging sea conditions experienced in this area of the world.”

The vessels will be diesel-electric hybrid power, with diesel generators and batteries providing electrical power for azimuth thruster propulsion. KiwiRail is focussed on maximising efficiency and incorporating environmental features to minimise CO2 emissions. This includes making the ferries adaptable to new fuel sources as they become available.   

“Future-proofing the vessels so they can become even more efficient in future is important to us, as our goal is to reduce KiwiRail’s carbon emissions by 30% by 2030 and become carbon neutral by 2050. We estimate that from day-one the new ferries will reduce the Interislander’s emissions by 40 per cent,” Walter Rushbrook, KiwiRail’s Interislander General Manager, said.

The Isle of Man Ship Registry said it believes that flag states have a key role to play in promoting a green agenda and supporting a global reduction in ship emissions. It supports the International Maritime Organisation’s 2050 target to cut greenhouse gas emissions, and in 2014, it launched a Green Fee scheme that offers financial incentives to ship owners which adopt energy-efficient ship designs that reduce fuel consumption and air pollution.