Flying ships

Soon, electric passenger ferries skimming above the surface across the seas may become a reality. Researchers at SSPA and Chalmers University of Technology have created a unique method for further developing hydrofoils that can significantly increase the range of electric vessels and reduce the fuel consumption of fossil-powered ships by 80 percent.  

While the electrification of cars is well advanced, the world's passenger ferries are still powered almost exclusively by fossil fuels. The limiting factor is battery capacity, which is not enough to power ships and ferries across longer distances. But now, researchers at SSPA and Chalmers have succeeded in developing a method that can make the shipping industry significantly greener in the future. The focus is on hydrofoils that, like wings, lift the boat’s hull above the surface of the water and allow the boat to travel with considerably less water resistance. A technology that in recent years has revolutionized sailing, by which hydrofoils make elite sailors' boats fly over the surface of the water at a very high speed.
The researchers at SSPA and Chalmers now want to enable the sailboats' hydrofoil principle to be used on larger passenger ferries as well, resulting in major benefits for the climate. Even for ships that today run on fossil fuels the climate benefit could be significant, as similar hydrofoil technology could reduce fuel consumption by no less than 80 percent.

Unique measurement method arouses broad interest
At the centre of the research project is a unique measurement technique that the researchers have put together in order to understand in detail how hydrofoils behave in the water when, for example, the load or speed increases or the positioning of the hydrofoil changes. Using the data collected from the experiments, the team has developed and validated a method to simulate and predict with great precision how the hydrofoil would behave under a variety of conditions. The method is unique of its kind and can now be used to develop the design of hydrofoils for electric powered hydrofoil ferries.

Laura Marimon Giovannetti, researcher and project manager at SSPA, is the lead author of this study and has herself competed at the elite level for both the British and Italian national sailing teams. Today she is a research and development adviser to Sweden's Olympic committee and the Swedish national team with her sights set on helping the team win more medals at the Olympics in 2024. Marimon Giovannetti sees many possibilities for the unique measurement method developed by the team:

‑ At the Americas Cup in San Francisco Bay in 2013, it was the first time we saw a 72-foot sailing boat learning how to “fly” using hydrofoils during the competition. And since then, we've seen a huge increase in sailing boats with hydrofoils. With this new method and knowledge we are able to bring together a range of different branches of engineering – naval architecture, advanced materials and aeronautics as well as renewable energy.