breastshot waterwheel

Also known as: breast wheel

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Last updated

June 22, 2026

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A breastshot waterwheel is a type of waterwheel where water is directed to the wheel at approximately axle height. It functions through a combination of impulse from the water's flow and the weight of the water as it descends in the buckets. This design is contrasted with overshot and undershot wheels, which have different water entry points. Breast wheels were found to be more efficient than overshot wheels and less susceptible to flood damage. Improvements to breast wheels included ventilated buckets to allow trapped air to escape and close-fitting masonry walls to prevent water leakage.12

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energy conversion
Waterwheels
…a Scottish engineer, showed that breast wheels (i.e., those in which water enters at the 10- or two-o’clock position) were more efficient than overshot wheels and less vulnerable to flood damage. He used curved buckets and provided a close-fitting masonry wall to keep the water from flowing out sideways. In…
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…a Scottish engineer, showed that breast wheels (i.e., those in which water enters at the 10- or two-o’clock position) were more efficient than overshot wheels and less vulnerable to flood damage. He used curved buckets and provided a close-fitting masonry wall to keep the water from flowing out sideways. In…
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waterwheel
…the undershot wheel; second, the breast wheel; and third, the overshot wheel. These waterwheels generally used the energy of moving streams, but tidal mills also appeared in the 11th century.
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…the undershot wheel; second, the breast wheel; and third, the overshot wheel. These waterwheels generally used the energy of moving streams, but tidal mills also appeared in the 11th century.
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