treadwheels

A treadwheel, also known as a treadwheel crane or simply a treadwheel, is a type of hoist powered by human or animal locomotion. It consists of a large, cylindrical wheel mounted on an axle. Inside the wheel, a series of planks or steps are attached. When a person or animal walks on these steps, the wheel rotates, turning the axle. This rotation is then used to operate a winding drum, which lifts or lowers a load via a rope or chain.

Treadwheels were a significant development in mechanical engineering, particularly in the late Middle Ages and Renaissance. They offered a more efficient and powerful means of lifting heavy objects compared to simpler lever or pulley systems. Their primary applications were in construction, where they were used to hoist building materials like stones and timbers, and in mines for raising ore and water.

The size and design of treadwheels varied depending on the intended use and the power source. Larger wheels were typically used for heavier loads and were often powered by multiple individuals or animals. The operation of a treadwheel required coordination among those walking inside, as they needed to maintain a steady pace to ensure consistent lifting. While largely superseded by steam and electric power in modern times, treadwheels represent an important chapter in the history of mechanical power and labor-saving devices.