Siemens Energy is to supply the integrated electric propulsion system (EPS) for KiwiRail’s Interislander’s new rail-enabled, environmentally-friendly ferries.
The EPS 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 EPS for the two new Interislander ferries.
KiwiRail’s Interisland Resilience Connection (iReX) project is a $1.45 bill investment, which will see two new train ferries enter service in 2025 and 2026.
The project also includes modernised ferry facilities in Waitohi, Picton and Kaiwharawhara in Wellington, including berths, terminals and both rail and road connections.
Selecting Siemens Energy as the EPS manufacturer is another 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, the company claimed.
Massimo Soprano, iReX Ships Programme Manager, said that the Siemens Energy system selected will deliver performance improvements in safety, manoeuvrability, as well as in reducing environmental impact for the Interislander operations.
The hybrid technology, which will 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.
The propulsion system will use ‘pods’, which are mounted outside the hull of the vessel, and contain an electric motor to drive the external propeller. The pods can rotate through 360 deg independently or working together providing greater manoeuvrability, particularly during berthing, and greater fuel efficiency, compared to the current ferries, which use a conventional shaft line/twin propellers to drive the ships.
Podded propulsion can deliver power to any direction, which enables a much higher level of control in prevailing conditions. They are also quieter underwater and create little or no vibration. The pods are powered by electricity and the combination of diesel generators and hybrid battery systems means operators have more control over consumption, power supply options, redundancy, and resilience.
Other significant suppliers for the vessels to date include Kawasaki Heavy Industries of Japan who will supply four 2,800 Kw bow thrusters for each of the new ferries and Mitsubishi Heavy Industries, which will supply the fin stabilisers.