Your Waterwheel Solution

The Overshot WaterWheel

The overshot wheel is the most common wheel seen in North America. It is a gravity wheel. This means that it harnesses the force of gravity acting vertically on the water as it travels from the top to the bottom of the wheel. Properly designed for the particular site, and correctly timed an overshot wheel can slow the natural velocity of the falling water to as little as 10% of what it would be if the wheel was not there.

The overshot wheel is most effective when it turns as slow as it possibly and still handle the total flow of water available to it. The rim speed should be only about 3 feet per second. The larger the wheel the slower it will need to turn. The incoming water must be traveling about three times the rim speed of the wheel so that it can fill the buckets effectively. This requires a foot or more of head over the wheel usually controlled by a gate.

To prevent dragging during a flood period the wheel must be held at least a foot above the tail water. The buckets start spilling water well before reaching the bottom. This along with the sacrifice of two or more feet of head above and below reduces the efficiency of the wheel to 70-75%.

One would need a 12 ft. or higher fall in order to use a 10 ft. wheel. Over shoot wheels have been made as high as 70 ft. but most were no higher than 30 ft. The overshoot wheel will work as well today as it did a hundred years ago.

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