Editing Paddle steamer (section)

===Sidewheeler===

The earliest {{nautical term|steam vessel}}s were sidewheelers, and the type was by far the dominant mode of marine steam propulsion, both for steamships and steamboats, until the increasing adoption of [[Propeller|screw propulsion]] from the 1850s. Though the side wheels and enclosing [[sponson]]s make them wider than sternwheelers, they may be more maneuverable, since they can sometimes move the paddles at different speeds, and even in opposite directions.  This extra maneuverability makes side-wheelers popular on the narrower, winding rivers of the [[Murray–Darling basin|Murray–Darling system]] in Australia, where a number still operate.

European sidewheelers, such as {{ship|PS|Waverley}}, connect the wheels with solid drive shafts that limit maneuverability and give the craft a wide turning radius. Some were built with paddle clutches that disengage one or both paddles so they can turn independently. However, wisdom gained from early experience with sidewheelers deemed that they be operated with clutches out, or as solid-shaft vessels.  Crews noticed that as ships approached the dock, passengers moved to the side of the ship ready to disembark. The shift in weight, added to independent movements of the paddles, could lead to imbalance and potential [[capsizing]]. Paddle tugs were frequently operated with clutches in, as the lack of passengers aboard meant that independent paddle movement could be used safely and the added maneuverability exploited to the full.

Most sidewheelers used two wheels, but some ships had multiple wheels behind each other. The [[SS Bessemer]] was a noteworthy example.