Rotor ship
![](http://upload.wikimedia.org/wikipedia/commons/thumb/c/cc/Cargo_E-Ship_1%2C_Emder_Hafen%2C_CN-03.jpg/220px-Cargo_E-Ship_1%2C_Emder_Hafen%2C_CN-03.jpg)
A rotor ship is a type of ship designed to use the Magnus effect for propulsion. The ship is propelled, at least in part, by large powered vertical rotors, sometimes known as rotor sails. German engineer Anton Flettner was the first to build a ship that attempted to tap this force for propulsion, and ships using his type of rotor are sometimes known as Flettner ships.
The Magnus effect is a force acting on a spinning body in a moving airstream, which produces a force perpendicular to both the direction of the airstream and the axis of the rotor.
Principles of operation
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/15/Sketch_of_Magnus_effect_with_streamlines_and_turbulent_wake.svg/220px-Sketch_of_Magnus_effect_with_streamlines_and_turbulent_wake.svg.png)
A rotor or Flettner ship is designed to use the Magnus effect for propulsion.[1] The Magnus Effect is caused by a spinning body in a moving airstream, or a moving body which is spinning (such as a ball), which pulls the air round to one side of the object, using the skin friction, creating a difference in air pressure from one side to the other. This causes a sideways force on the object making the spinning body move towards the low pressure side where there is least resistance. On a ship, this sideways force is resisted by the hull, and a component of this force can be used to propel the ship forward, provided that the ship's direction is generally within the low pressure zone. A Magnus rotor used to propel a ship is called a rotor sail and is mounted with its axis vertical. When the wind blows from the side, the Magnus effect creates a forward thrust. The most common form of rotor sail is the Flettner rotor.[2][failed verification] The wind does not power the rotor, which is rotated by its own power source.
Due to the arrangement of forces, a rotor ship is able to sail closer to the wind than a conventional sailing ship. Other advantages include the ease of control from sheltered navigation stations and the lack of furling requirements in heavy weather.[2]
If the ship changes tack so that the wind comes from the other side, the direction of rotation must be reversed; the ship would otherwise be propelled backwards.[2]
Sailing ships, including rotor ships, often also have a small conventional propeller to provide ease of manoeuvrability and forward propulsion at slow speeds and when the wind is not blowing or the rotor is stopped. In a hybrid rotor ship the propeller is the primary source of propulsion, while the rotor serves to offload it and thus increase overall fuel economy.[2] Rotor sails have been reported to generate 5-20% fuel savings.[3]
History
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/3f/Buckau_Flettner_Rotor_Ship_LOC_37764u.jpg/220px-Buckau_Flettner_Rotor_Ship_LOC_37764u.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Vaixell_de_rotor_Barbara.jpg/220px-Vaixell_de_rotor_Barbara.jpg)
Pioneers
The German engineer Anton Flettner was the first to build a ship which attempted to use the Magnus effect for propulsion.[4][5]
The Buckau
Assisted by
The Buckau sailed from
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.[9]
That view stands in contrast to others that claim "Due to the impressive performance, the Buckau was put into service to carry bulk cargo across the North Atlantic and the Baltic sea (Seufert & Seufert, 1983). 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.)." [10]
The latter assessment seems to be more accurate, as the outcome of the Buckau experiment, resulted in the development of the next rotor ship, the Barbara.
The Barbara
In 1926, a larger ship with three rotors, the Barbara was built by the shipyard
Modern vessels
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f2/Uni-Kat_Kiel2007.jpg/220px-Uni-Kat_Kiel2007.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/32/Norsepower_rotor_sails_modern_version_of_flettner_rotor.jpg/220px-Norsepower_rotor_sails_modern_version_of_flettner_rotor.jpg)
Interest in rotor sails revived in the 1980s, as a way of increasing the fuel efficiency of a conventionally powered ship.
Enercon launched the hybrid rotor ship E-Ship 1 on 2 August 2008. From 2010, it has been used to transport the company's turbine products and other equipment.[12][13] Enercon claim "operational fuel savings of up to 25% compared to same-sized conventional freight vessels."[14]
The University of Flensburg is developing the Flensburg catamaran or Uni-Cat Flensburg, a rotor-driven catamaran.[15]
In 2007, Stephen H. Salter and John Latham proposed the building of 1,500 robotic rotor ships to
In 2009, Wärtsilä proposed a cruiseferry that would use Flettner rotors as a means of reducing fuel consumption. The Finnish ferry operator Viking Line adopted the idea, with MS Viking Grace built in 2011–2012, initially without rotors.[18] A rotor system was retrofitted in 2018.[19]
In 2014 and 2015, Norsepower installed twin rotor sails on Finnish shipping company Bore's RoRo vessel M/V Estraden.[20][21][22] In May 2018, the 1996 built cargo ship Fehn Pollux of the German-based Fehn Shipmanagement (Leer) was fitted with an 18-metre long Flettner rotor of the EcoFlettner type at the front.[23]
In 2018, Norsepower deployed rotor sails with the world's biggest shipping company, Maersk. The Maersk Pelican, an LR2 class tanker, has been fitted with two Norsepower Rotor Sails.[24][25]
The MV Afros (IMO 9746803) bulk carrier has operated four movable rotors over a year with positive results.[26][27][28][29]
In 2021, Norsepower installed five tilting rotor sails onto a Vale-operated iron ore carrier; the tilting design intended to allow maneuvering below bridges.[3][30]
Scandlines operates two hybrid ferries with rotorsail, M/F Copenhagen and M/F Berlin.[31]
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. [32]
See also
References
- ISBN 978-1-315-86304-7.
- ^ a b c d Gilmore, C.P. (1984). "Spin Sail: Harnesses Mysterious Magnus Effect for Ship Propulsion," Popular Science (January), pp. 70-73, see [1], accessed 13 October 2015.
- ^ a b "Sea Cargo Ship To Be World's First Vessel With Tilting Rotor Sails Arrives In Rotterdam". www.marineinsight.com. 13 January 2021. Retrieved 2021-01-25.
- ^ Anon.; "America's First Rotor Boat", Popular Science Monthly, September 1925, page 27.
- ISBN 978-0-486-15265-3.
- ^ a b Seufert, Wolf & Seufert, Ulrich; "Critics in a spin over Flettner's Ships", New Scientist, 10 March 1983, pp. 656-659.
- ISBN 978-0-486-68103-0.
- ^ United States Naval Institute (1970). Proceedings.
- ISBN 9780750960977.)
{{cite book}}
: CS1 maint: location (link - ^ a b "History of Flettner Rotors".
- ISBN 978-1-84832-072-7.
- ISBN 978-3-319-29838-2.
- ^ Kennedy, John (2010). "Discovery: State-of-the-art cargo ship to dock with haul of wind turbines". Silicon Republic (Online, August, 10). Retrieved 12 October 2015.
- ^ Anon. (2012). "PM E-Ship1 Ergebnisse DBU" (PDF). Enercon.de. Archived from the original (PDF) on June 7, 2014. Retrieved 2015-10-12.
- ^ Anon. (2015). "Flettner rotor". Thiiink Holding. Retrieved 12 October 2015.
- ^ Latham, John (2007). "Futuristic fleet of 'cloudseeders' (15 February)". BBC. Archived from the original on 2012-08-25. Retrieved 2012-07-25.
- PMID 18757273. Retrieved 2009-07-27.
- ^ Reinikainen, Kari (2009). "Wind and lng [liquified natural gas] power Wartsila's cruise ferry design". Cruise Business Online (22 June). Archived from the original on 2011-07-08. Retrieved 2010-01-19.
- ^ Bryce, Emma (29 May 2018). "Cheap oil killed sailing ships. Now they're back and totally tubular". Wired UK. Retrieved 29 May 2018.
- ^ "ESTRADEN with Flettner rotor is underway". 10 December 2014.
- ^ "State of technology" (PDF). 2022-05-10.
- ^ "Norsepower". www.norsepower.com. Retrieved 2016-11-25.
- ^ With Flettner's wind power. In: Hansa International Maritime Journal, 9/2018, Hamburg 2018, p. 58/59
- ^ "Rotor Sails Fitted on board Maersk's Tanker in a World's 1st". Aug 30, 2018.
- ^ "Norsepower Rotor Sails Confirmed Savings Of 8.2% Fuel And Associated Co2 In Maersk Pelican Project". Oct 24, 2019.
- ^ Shipping, Green (13 March 2019). "Blue Planet Shipping receives GREEN4SEA Dry Bulk Operator Award". SAFETY4SEA. Retrieved 6 April 2019.
- ^ "Video: ANEMOI Flettner Rotor System – MV Afros Sailing". YouTube. 4 June 2018. Archived from the original on 2021-12-21.
- ^ "Video: ANEMOI moving Flettner Rotor System – MV Afros Berthing". YouTube. 26 November 2018. Archived from the original on 2021-12-21.
- ISSN 0362-4331. Retrieved 2021-06-29.
- ^ "Norsepower: 5 tiltable rotor sails installed on Vale-chartered ore carrier". Offshore Energy. 2021-05-14. Retrieved 2021-06-09.
- ^ "M/S Berlin gets a new rotor sail: Ingeniøren observes the process". ING. 2022-05-30. Retrieved 2022-09-14.
- ^ "Airbus renewing ocean transport vessel fleet to assist A320neo ramp-up demand". 2023-10-25. Retrieved 2023-10-25.
External links
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)