Paddle steamer

A paddle steamer is a steamship or riverboat powered by a steam engine that drives paddle wheels to propel the craft through the water.

In antiquity, paddle wheelers followed the development of poles, oars and sails, where the first uses were wheelers driven by animals or humans.

Modern paddle wheelers may be powered by diesel engines. Save for tourism and small pleasure boats (paddle boats), paddle propulsion is largely superseded by the screw propeller and other marine propulsion systems that have a higher efficiency, especially in rough or open water.

Paddle wheels

The paddle wheel is a large steel framework wheel. The outer edge of the wheel is fitted with numerous, regularly-spaced paddle blades (called floats or buckets). The bottom quarter or so of the wheel travels underwater. An engine rotates the paddle wheel in the water to produce thrust, forward or backward as required. More advanced paddle wheel designs feature feathering methods that keep each paddle blade closer to vertical while in the water to increase efficiency. The upper part of a paddle wheel is normally enclosed in a paddlebox to minimise splashing.