Finnsirius © Finnlines

Finnlines' two RoPax vessels

Why was an integrated hybrid solution for two new RoPax vessels the perfect choice to support Finnlines’ long-term decarbonisation goals?

How a hybrid solution is making ferry travel more energy efficient for Finnlines

Finnlines is dedicated to providing reliable connections across the Baltic Sea in the most sustainable and environmentally friendly way possible. How does the integrated hybrid solution onboard their two new RoPax vessels help them deliver on this commitment?

Finnlines’ new Superstar-class RoPax vessels will operate on the Baltic Sea between Finland and Sweden. The ferries are 235 metres long and can carry about 200 cars and 300 lorries per voyage as well as a large amount of cargo and 1,100 passengers.

Environmental considerations and sustainability are high priorities on the vessels. Both ships are equipped with a shore connection and can plug into the local power grid for quiet and emission-free port stays. The hybrid solutions will reduce fuel consumption and allow zero emissions at berth.

Comfort on board for passengers is also a key, and the vessels also provide customer amenities including a spa and several restaurants.


An all-in-one package for zero-emission operation

Wärtsilä supplied four Wärtsilä 46F engines along with transverse thrusters, a hybrid solution, and a state-of-the-art electric package as one unified, fully integrated solution for Finnlines. The hybrid shaft generator system uses a fully integrated multidrive capable of driving the shaft generators in both directions as motors and/or generators. Having a shaft generator reduces fuel consumption and costs while cutting carbon emissions.

The package also includes the thrusters and thruster control system, as well as a highly efficient energy management system that controls the flow of energy between different power sources, optimising performance. The system will enable the vessels to operate without emissions while in port, using either batteries or shore power.

The integrated hybrid drive system is the heart of the vessels’ electrical power distribution, dynamically controlling power flows in multiple directions. The system has built-in redundancy, with each of the vessels’ two propeller shaft lines having its own drive system. 

Finnlines wanted to work with a single partner that was capable of managing a large and complex system integration project like this.


Future-proof flexibility wins awards

“We’ve worked with Finnlines for decades, and this project builds on our long history of cooperation,” says Markus Nyström, Senior Sales Manager at Wärtsilä. “Finnlines was interested in having our market-leading energy management system on their vessels and they have been very happy with our solution. They needed future-proof vessels with a lot of flexibility when it comes to how they can be operated in the longer term, and Wärtsilä was able to deliver just that flexibility needed.”

“The key to this flexibility lies with our integration expertise, which ensures that the energy management system, hybrid drive system and power management system can interact with one another correctly,” says Richard Heber, Manager, Shaft Generator Systems Delivery at Wärtsilä.

The vessels were built at the China Merchants Jinling Shipyard (Weihai) in China. Wärtsilä worked closely with the shipyard to ensure the integrated solution was delivered and installed successfully on the vessels. The vessel Finnsirius was delivered in July 2023 and is now in service.

The second vessel, Finncanopus, will undergo sea trials in November with delivery at the end of 2023. Finnsirius has since been named RoPax vessel of the year 2023 by the Ferry Shipping Summit, recognising its advanced sustainable hybrid technology and attractive design.

“Finnlines wanted to work with a single partner that was capable of managing a large and complex system integration project like this – and we were able to deliver,” says Nyström. 

“This investment is an important part of our efforts to lead the development of energy-efficient transport services in the Baltic region. Many of the vessels in our fleet already include Wärtsilä solutions, so we were confident that working with Wärtsilä on this complex integration project was the right choice. The integrated hybrid solution delivers the operational flexibility we need to future-proof the two new vessels so that they support our long-term decarbonisation goals.” Juha Ahia, Manager, Newbuildings & Projects, Finnlines.


Reduce emissions and enable zero-emissions in port for two newbuild ferries.


Four Wärtsilä engines along with thrusters, a hybrid system and a power management system supplied as one unified solution.


Fuel savings, lower CO2 emissions at sea and zero emissions at berth.

Learn more about optimising fuel consumption with Wärtsilä hybrid marine solutions.

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