Engineering:Twin-screw steamer

From HandWiki

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.[1]

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.[2]

References

  1. "Maritime Acronyms and Abbreviations". http://www.rina.org.uk/maritime_acronyms1.html. 
  2. Danton, Graham (31 October 1996). The Theory and Practice of Seamanship. Routledge. pp. 51–55. ISBN 978-0415153720.