Swedish shipping company Wallenius Marine is developing a ship called Oceanbird, which could transport 7,000 cars and trucks across the Atlantic propelled only by the wind.

The concept, which is essentially an outsized sailboat, would be twice as high as the largest comparable vessel due to the five 80-metre-tall sails that protrude from its hull.

These purportedly would make it the world's largest wind-powered vessel, capable of travelling across the ocean to the US at a speed of 10 knots and with a total journey time of 12 days.