Norsepower says that new independent tests have shown that its Rotor Sail technology will deliver ‘great potential savings’ on Viking Line’s cruise ferry M/S Viking Grace.
Original tests – which looked at fuel consumption alone – showed no evidence of any immediate savings.
However, ABB and NAPA were asked to review the data, and identified a change in the propulsion power breakdown of Viking Grace, caused by the Rotor Sail.
A similar conclusion was confirmed using strain gauge analysis – where forward thrust of the Rotor Sail was measured and converted into propulsion power.
Together, the new analysis shows that long-term LNG marine fuel savings will be around 300 tonnes a year.
The data also showed that the Rotor Sail delivers more forward thrust on the open sea legs of the route for the Viking Grace, but due to the route being located mostly in the archipelago, the annual fuel savings potential is on the same level within both route areas.
The new results have encouraged Viking Line and Norsepower to continue their collaboration.
“The results confirm our technology works with high-speed cruise ferries and that favourable results can be achieved with a service speed of 21 knots,” says Tuomas Riski, CEO, Norsepower.
“We have used the Rotor Sail in extreme weather, including icing events and high wind speeds, when it has remained operational – so we know it can be used throughout the year without any weather-related issues.”
Jaakko Talonen, data scientist, NAPA added: “In the actual navigational conditions there is always variation in the environment, which has an important effect on the fuel consumption. This is why a statistical regression model was applied, to overcome the variations in the comparison conditions and to disclose the effect of the Rotor Sail.”
Marcus Högblom, head of passenger vessels at ABB Marine & Ports, says: “This new analysis shows the importance of onboard data collection and the value of analytical services.
“Besides optimising operations through improved energy efficiency on board Viking Grace, the data collected by the ABB Ability Marine Advisory System OCTOPUS was used to calculate the savings gained from the Rotor Sail without disturbing operations.”