KIWIRAIL’S two new Interislander rail-enabled ferries will feature Siemens Energy’s electric propulsion system.

The system includes the alternators, switchboards, batteries, azimuth thrusters, power and battery management systems and integrated alarm system.

 In addition, Hyundai Mipo Dockyard and Siemens Energy entered into a contract to design, supply, install, and commission the electric propulsion systems for the new ferries.

The Interisland Resilience Connection (iReX) project is a NZ$1.45 billion investment that will see two new, rail-enabled ferries coming into service in 2025 and 2026. The project also includes modernised ferry precincts in Waitohi Picton and Kaiwharawhara in Wellington, including ferry berths, terminals and both rail and road connections.


Selecting Siemens Energy as the maker for the electric propulsion system is a step towards the 40% reduction in emissions that the new fleet will bring to Interislander operations and KiwiRail’s goal of net-zero carbon emissions by 2050.

iReX ships programme manager Massimo Soprano said the Siemens Energy system selected would deliver performance improvements in safety, manoeuvrability as well as in reducing environmental impact for the Interislander operations.

The hybrid technology selected to drive the new ferries will use electrical propulsion from generators fuelled by diesel and batteries recharged by electrical shore power.

Batteries will power 30% of the three-hour journey. Under normal conditions, the ferries will be operating on batteries only while manoeuvring and in port, using a combination of battery and shore power. Any surplus energy produced by the generators during sailing can also be battery stored.