As part of a research collaboration between the KTH Royal Institute of Technology, the shipping company Wallenius and the marine technology company SSPA, the cargo ship Oceanbird is being created, with the goal of reducing emissions by 90%.
In recent weeks, researchers from the KTH Center for Naval Architecture have tested a model of the 7-meter-long ship in the waters of the Stockholm archipelago, as well as in a laboratory at the KTH campus in Stockholm. If all goes according to plan, it is hoped that the first full-scale ship will sail in four to five years.
Shipping currently emits around 940 million tonnes of CO2 per year and is responsible for around 2.5% of global greenhouse gas emissions, according to the International Maritime Organization.
But instead of internal combustion, Oceanbird is intended to be propelled by four large sails, each 100m high, which catch the wind and propel the ship forward. The 200 m long ship would sail at 10 knots, so an Atlantic crossing would take 12 days, compared to eight days for current freighters.
With telescopic masts that could be lowered to 50m to clear decks, the ship would also use auxiliary electric motors when maneuvering in cramped harbors.
Using a 1:30 scale model from Oceanbird, testing in Stockholm involves measuring flow conditions around the wings and optimizing routing to meet ideal wind conditions, says Jakob Kuttenkeuler , professor at the Center for Naval Architecture. The collaborating partners are confident in the success of the sailboat’s scale-up, although there are engineering issues to be addressed along the way. “As you increase, a lot of things change,” he says.
“Mass, stability and length are easy to increase while some aerodynamic and hydrodynamic effects are more difficult to scale properly,” says Kuttenkeuler. For example, wave formation and wind speed will make the difference.
“Also at a deeper level of flow mechanics, there are a lot of changes that apply to the release around the wings and rudders,” he says.
The ship has no restrictions on what it can carry. In the research collaboration, however, the ship is intended to transport individual cars, trucks, machinery, and possibly train cars. Researchers say the ship could carry up to 6,000 automobiles per trip.
The hope is that Oceanbird will also pave the way for not only more winged cargo ships, but cruise ships as well.