Patent Model for a Feathering Paddle Wheel, 1877

This patent model accompanied Henry William’s patent application for “a new way to feather the floats of a paddle wheel” that received patent number 189164 on April 3, 1877. Each blade in Williams's design rides on the end of a shaft. T-levers at the ends of the shafts carry rollers set into grooves cut into a central, immobile cam. As the wheel rotates, the blades turn as the grooves direct, presenting knife edges to the water when entering and rising, but offering resistance to the water when in the optimal position to push the vessel forward.

While the last generation of ocean paddle-wheel steamships emerged from European and American shipyards in the 1860s, paddle wheels remained the favored means of propulsion for steamers on the shallower waters of rivers and bays until the mid-twentieth century. Consequently, inventors like Henry Williams continued to suggest improvements to paddle wheel efficiency. For most of each turn, a paddle wheel slices ineffectively through the air. Then, when it enters the waves, it wastes energy pressing down on the water. After a brief passage moving the vessel forward, the paddles waste more effort churning the surface as they rise into the air once more. Feathering paddle wheels reduce this waste and, at the same time, cut noise and vibration in the boat. Never universally adopted, feathering wheels with their many moving parts are prone to damage and expensive to maintain. Williams's design, although particularly elegant, is not had no commercial success.

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