right|thumb|240px|The S/S ''Ukkopekka'', a Finnish screw steamer A screw steamer or screw steamship is an old term for a steamship or steamboat powered by a steam engine, using one or more propellers (also known as ''screws'') to propel it through the water. Such a ship was also known as an "iron screw steam ship". In the 19th century, this designation was normally used in contradistinction to the paddle steamer, a still earlier form of steamship that was largely, but not entirely, superseded by the screw steamer. Many famous ships were screw steamers, including the RMS ''Titanic'' and RMS ''Lusitania''. These massive leviathans had three or four propellers. Ships under two hundred meters in length usually only had two or one propellers.Canney, 1998 pp.26-27


The screw or propeller was first developed by Swedish inventor John Ericsson for the U.S. Navy. Ericsson was the principal designer of the Monitor class of vessels. In 1844, Thomas Clyde partnered with Ericsson to apply his screw-propeller to steam vessels. After several experimental versions, Clyde launched the twin-screw propeller steamer ''John S. McKim'' making it the first screw steamer built in the United States for commercial use.

See also

* List of ships * - the world's first steamship to be driven by a screw propeller




External links

* Category:Marine steam propulsion Category:Marine propulsion Category:Ship types {{water-transport-stub