The first long-term test of a rotor sail fitted on a passenger ferry is coming to an end after three years aboard Viking Line’s Viking Grace. According to both the line and the technology company, the tests provided important data demonstrating the benefits of the rotor sail concept and helping to advance the technology. The test was also the first aboard an LNG-fueled ship creating the first LNG-wind electric propulsion hybrid ship.
During the test, the Viking Grace was able to reduce its emissions, fuel burn, and fuel costs according to data released by Norsepower, developer of the rotor sail. They estimated the annual reduction in carbon emissions at approximately 900 tons, which they said was equivalent to reducing LNG fuel consumption by 300 tons per year.
The rotor sail, which stands approximately 79 feet and has a diameter of 13 feet, was fitted on the 57,565 gross ton Viking Grace in 2018. The vessel, which is 715 feet long, operates on a 12-hour trip between Stockholm, Sweden and Turku, Finland with an intermediary stop in the Aland Islands at speeds ranging between 13 and 21 knots.
The rotor sail generates thrust utilizing the Magnus effect, thus reducing the vessel’s need for propulsion force. The fully automated system detected situations in which wind conditions were favorable for the operation of a rotor sail and automatically started the sail. Read on.