Editing Propeller (section)

===Skewback propeller===
An advanced type of propeller used on the American [[Los Angeles-class submarine]] as well as the German [[Type 212 submarine]] is called a '''skewback propeller'''. As in the [[scimitar propeller|scimitar blades]] used on some aircraft, the blade tips of a skewback propeller are swept back against the direction of rotation. In addition, the blades are tilted rearward along the longitudinal axis, giving the propeller an overall cup-shaped appearance. This design preserves thrust efficiency while reducing cavitation, and thus makes for a quiet, [[Stealth technology|stealthy]] design.<ref name="JMCWebCreation and Co, 2009">{{cite web |title=Silent propellers|url= http://www.francehelices.fr/silent-propellers.htm|website=France helices |publisher=JMC Web Creation & Co|access-date=July 21, 2017 |date=2009|archive-url=https://web.archive.org/web/20070926223647/http://www.francehelices.fr/silent-propellers.htm|archive-date=September 26, 2007|url-status=dead}}</ref><ref>{{Citation | title = About Propellers | publisher = GSI Tek props | place = UK | url = http://www.gsitek-props.co.uk/about_propellers.htm}}</ref>

A small number of ships use propellers with [[winglet]]s similar to those on some airplane wings, reducing tip vortices and improving efficiency.<ref>Godske, Bjørn. "[http://ing.dk/artikel/dansk-udviklet-energibesparende-propeller-solgt-til-man-dieselturbo-128613 Energy saving propeller]" (in [[Danish language|Danish]]) ''[[Ingeniøren]]'', 23 April 2012. Accessed: 15 March 2014. [https://translate.google.com/translate?hl=da&sl=da&tl=en&u=http%3A%2F%2Fing.dk%2Fartikel%2Fdansk-udviklet-energibesparende-propeller-solgt-til-man-dieselturbo-128613 English translation]</ref><ref>Godske, Bjørn. "[http://ing.dk/artikel/kappel-propellere-baner-vej-succes-hos-man-167005 Kappel-propellers pave the way for success at MAN]" (in [[Danish language|Danish]]) ''[[Ingeniøren]]'', 15 March 2014. Accessed: 15 March 2014. [https://translate.google.com/translate?hl=da&sl=da&tl=en&u=ing.dk%2Fartikel%2Fkappel-propellere-baner-vej-succes-hos-man-167005 English translation]</ref><ref>"[http://www.mandieselturbo.com/1019133/Press/Press-Releases/Trade-Press-Releases/Marine-Power/Propeller-Equipment/Kappel-Agreement-Secures-Access-to-Major-Market.html Kappel agreement secures access to major market]", Man diesel turbo, 30 August 2013.</ref><ref>"[http://www.support-project.eu/supportknowledge/defaultinfo.aspx?topicid=145&index=6 Kapriccio Project] {{Webarchive |url= https://web.archive.org/web/20140315174525/http://www.support-project.eu/supportknowledge/defaultinfo.aspx?topicid=145&index=6 |date=2014-03-15}}" [[European Union]]. Accessed: 15 March 2014.</ref><ref>"[http://www.marinelink.com/news/article/industry-pays-tribute-to-innovation-awards/307142.aspx Industry Pays Tribute to Innovation Awards Winners]" ''Marine link'', 3 October 2002. Accessed: 15 March 2014. Quote: "Winner: the energy-saving Kappel propeller concept from the European Commission-funded Kapriccio propulsion research project. Blades curved towards the tips on the suction side reduce energy losses, fuel consumption, noise and vibration"</ref><!--may not be skewback-->

{{See also|astern propulsion}}