Rotor ship

This causes a sideways force on the object making the spinning body move towards the low pressure side where there is least resistance.

Other advantages include the ease of control from sheltered navigation stations and the lack of furling requirements in heavy weather.

[9] The ship could tack (sail into the wind) at 20–30 degrees,[8] hence the rotors did not give cause for concern in stormy weather.

[10] Some sources claim that the ship had proved inefficient on these voyages, that the power consumed by spinning 15-metre tall drums was disproportionate to the propulsive effect when compared with conventional propellers.

On 31 March 1926, the Buckau, now renamed Baden-Baden sailed to New York via South America, the 6,200 nautical mile voyage across the Atlantic used only 12 tons of fuel oil, compared with 45 tons for a motor ship of the same size without rotors (Nuttall & John, 2016), arriving in New York harbor on 9 May (History of Flettner Rotor, n.d.)."

In addition to this, Marine Diesel Oil (MDO) and the related engine technology required to use it became readily and cheaply available (Nuttall & John, 2016).

Fuel prices at that point meant that any savings achieved by the rotor were too small for shipping companies to consider the investment due to the lengthy payback period.

[18] In 2007, Stephen H. Salter and John Latham proposed the building of 1,500 robotic rotor ships to mitigate global warming.

The rotors were made of carbon fibre and were attached to a retrofitted trimaran and propelled the vessel stably through the water at a speed of six knots.

[22] In 2014 and 2015, Norsepower installed twin rotor sails on Finnish shipping company Bore's RoRo vessel M/V Estraden.

[34] In October 2023 Airbus announced that it had commissioned six ships with Flettner rotors for entry into service in 2026 to transport aircraft sections to its US assembly line.