a vessel driven by bladed wheels. Paddles (blades) are mounted around the outer circumference of the wheel, the axle of the wheel is located above the waterline on opposite sides of the vessel or in the stern. The overall width of a side-wheeler is usually at least double the width of the hull; with stern-wheelers the length is increased.
Paddle-wheelers gained wide use after steam engines appeared (in the late 18th and early 19th centuries), initially on rivers and later on the seas as well. A paddle-wheeler was the first machine-powered vessel to cross the Atlantic (1838). The largest cargo and passenger oceangoing paddle-wheeler was the Great Eastern (1857). It was 207 m long and 25.3 m wide, with a displacement of 27,400 tons. Steam engines with 3,680 hp turned the side paddle wheels, which were 17 m in diameter; the vessel also had a propeller, driven by an engine of 3,970 hp, and sails on six masts.
Initially all vessels with mechanical engines had paddle wheels, but because of their frequent breakdowns in rough seas the paddle-wheelers soon gave way to propeller-driven vessels. On inland waterways, paddle-wheelers survived the handicaps of large size, great weight, and complexity of construction for a comparatively long time because of the high efficiency of the paddle wheels. However with the appearance of more advanced designs of ship propulsive devices that operated well in shallow waters, the paddle-wheelers were virtually eliminated in favor of vessels with propellers, water jets, and rotor propulsion.
E. G. LOGVINOVICH