Twin-screw steamer

{{Short description|Type of steam powered ship}} A '''twin-screw steamer (or steamship)''' ('''TSS''') is a steam-powered vessel propelled by two screw propellers, one on either side of the plane of the keel.<ref name="tss-defn">{{cite web|url=http://www.rina.org.uk/maritime_acronyms1.html|title=Maritime Acronyms and Abbreviations|website=Royal Institution of Naval Architects|id=TSS|url-status=dead|archive-url=https://web.archive.org/web/20160819043306/http://www.rina.org.uk/maritime_acronyms1.html|archive-date=19 August 2016}}</ref>

==Arrangement== All propellers produce a transverse thrust, also called screwing effect or starting bias, which gives a tendency for end of ship to move sideways. In a twin-screw ships the port propeller is usually left-handed and the starboard right-handed, to cancel out the transverse thrust and avoid propeller walk.<ref name="PoShipH">{{cite book|title=The Theory and Practice of Seamanship|section=The Principles of Ship Handling|pages=51–55|isbn=978-0415153720|date=31 October 1996|publisher=Routledge|last=Danton|first=Graham}}</ref>

==References== {{Reflist}}

Category:Steamboats Category:Ship types

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