Viking Line has commenced the operation of a passenger ship powered by a wind-assisted rotor sail between Turku, Finland, and Stockholm, Sweden.

Developed and retrofitted by Finnish company Norsepower, the rotor sail solution is expected to allow the passenger ship Viking Grace to reduce fuel consumption and cut emissions by up to 900t per year, depending upon the wind conditions.

The vessel’s cylindrical rotor sail is 24m in height and 4m in diameter, while it uses the Magnus effect for propulsion.

It will be propelled when its rotor spins and the passing air will flow with a lower pressure on one side than the opposite side.

The automated rotor sail system is designed to shut down whenever it comes into contact with any disadvantageous changes in the direction or force of the wind.

“Norsepower has developed a world-class mechanical rotor sail solution that will reduce fuel consumption.”

Viking Line CEO Jan Hanses said: “As an Åland shipping company, we rely on the sea for our livelihood so it’s of prime importance for us to promote the well-being of the marine sea.

“We want to pioneer the use of solutions that reduce the environmental load. Based in Finland, Norsepower has developed a world-class mechanical rotor sail solution that will reduce fuel consumption.”

Viking Grace has been in operation since 2013 and uses liquefied natural gas (LNG) to conduct its journeys.

Viking Line is also set to use wind propulsion to power its new passenger ship, which is scheduled to enter service in 2020.

The ship was built in China and features two mechanical rotor sails provided by Norsepower.