In 1926, a 2,000-ton steel-hulled schooner namedBuckaumade an extraordinary crossing across the Atlantic.
Although theBuckauwas technically a sailing ship, it had no sailsat least, not conventional ones.
The vertical columns on this ship are not smokestack.
They are rotating sails.
The pressure difference between the front and the back surface of the rotor pushed the ship forward.
Graphics adapted from Science Mag.
TheBuckauperformed magnificently, moving at nearly twice her former speed.
She could also tack to the wind at a shallower angle compared to conventional sailing ships.
She handled the stormy weather exceptionally well because she had no sails.
Fossil fuel, after all, was cheap and abundant.
She eventually sank in the Caribbean Sea in 1931.
Most sea-going vessels burn the dirtiest kind of fuel called Heavy Fuel Oil or bunker fuel.
Heavy Fuel Oil is cheap but it generates toxic chemicals when burned.
This is concerning since ships carry more than 90 percent of the worlds goods over the ocean.
The difference between diesel and bunker fuel.
Diesel is transparent while bunker fuel is thick and black.
This allows the main engines to be throttled back, saving fuel and reducing emissions.
Enercon claim the rotors have improved fuel savings by up to a quarter.
In 2015, Norsepower installed twin rotor sails on Finnish shipping company Bore’s RoRo vesselM/V Estraden.
In 2018, they fitted the cargo shipFehn Polluxwith an 18-meter-long Flettner rotor.
The same year, they started testing the rotor concept with the world’s biggest shipping company, Maersk.
The sails resulted in fuel savings of 8.2 percent, or about 1,400 tons of CO2.
The rotorship “Barbara” in the city of Barcelona (Catalonia) in 1926.
That means less electricity is required to spin the rotor, which translates into more efficient propulsion.
One such example, beside rotor sails, is the kite sail.
Norsepower Rotor Sails onboard Maersk Pelican.
They are the largest Flettner rotors in the world.
Photo:Wilsca/Wikimedia Commons
Flettner rotors at the bow of the German RoLo cargo ship E-Ship 1.
