Since sails were replaced by steam in the early 1800s, sailing ships have existed as little more than an historical novelty or a hobby. They certainly haven’t been used commercially in the transport of cargo for a long time. But just like fashion cycles, transport technology appears to have come full circle with a Swedish shipbuilder unveiling a new high-tech wind powered and zero carbon footprint ship – the Oceanbird.
The Oceanbird’s sails are, however, very different to the rigging and masts of previous generations of sailing ships. The sails are referred to as “wings” and made from steel composite and masts swivel to optimise lift.
Swedish shipbuilder Wallenius Marine is behind the Oceanbird, which has been designed to carry up to 7000 cars across the Atlantic in just 12 days. While longer than the 7 days diesel-powered cargo ships can make the journey in, the Oceanbird is completely emissions free. It’s estimated that around 3% of global carbon emissions are a result of maritime transport. So zero carbon alternatives to diesel cargo ships could potentially make a significant impact on global emissions levels.
Wallenius’s chief operating officer Per Tunell comments:
“For the last 20 years we had a vision that we were going to build emission-free shipping. We looked at so many ways, and struggled for many years. We came to the conclusion it was only possible if we were utilising the energy around the vessel.”
The question for Wallenius Maritime’s engineers then become “what energy”? Solar was considered but couldn’t produce enough energy to power a huge cargo vessel. Waves weren’t consistent enough to provide the answer. That led the team back to the original renewable energy of the maritime industry – wind. The decision was made to reinvent the sailing ship, using the latest technology in the world.
The Oceanbird is the result of that work and has already been tested in scale prototypes. 2024 is being targeted for the first commercially manufactured models of the ship, which is intended for use on any ocean.
One advantage today’s sailors have over their historical peers is access to relatively accurate weather forecasting. Contemporary captains are unlikely to be caught out by doldrums and stranded mid-ocean with no wind. As Mr Tunell explains:
“A long time ago you didn’t have the forecasts we have today. Now, we think we can route the vessel so it is in favourable winds almost always.”
The sails themselves are also a step up in efficiency on old canvas versions. They were designed in partnership with the KTH Royal Institute of Technology in Stockholm. To get enough wind in them to power a cargo ship laden down with thousands of cars and far heavier than the fullest galleon of historical times, the engineers went for height.
KTH professor of maritime engineering Jakob Kuttenkeuler explains why a height of 100 metres was necessary:
“This boat is 100 metres high above the surface of the ocean. Normal sailing boats, which we have lots of experience in, only use the 30m close to the water. With this, that’s where we start to sail.”
Research into altitude measurements of weather at sea were conducted to understand what ocean wind behaviour was like at that height. Previously, nobody had much insight into atmospheric conditions 100 metres above sea level as its not a space we’ve ever really used before. The result was a design incorporating a series of tall, vertical wings that has resulted in “something completely different from ships 200 years ago. They were sailing with the wind, we are using the wind — which is different.”
Mr Kuttenkeuler concludes:
“During the last 100 years we have been cheating, combusting fossil fuels at a rate that can’t continue. We have to go back to something more sustainable. The time has come to sail again.”