Leffel Double Turbine Water Wheel

In 1862, James Leffel, a foundry operator in Springfield, Ohio, patented the "Double Turbine Water Wheel." Leffel's wheel departed significantly from previous designs by combining two wheels in a single case. The upper wheel was comprised of inward-flow buckets, while the lower wheel had axial-flow buckets that curved inward and downward. This "mixed flow" design resulted in a longer, narrower, and faster turbine which, according to Leffel, was capable "of yielding from ninety-two to ninety-five per cent. of the power of the water and a greater per cent. than any other wheel heretofore constructed."

Characterized by efficiency under a variety of water conditions, competitive pricing – from $350-$500 in 1862 – and excellent workmanship, demand for Leffel's wheel grew rapidly. Production rose from 47 turbines in 1862 to as many as 400-500 wheels by 1870. In 1867, the firm of Child & McCreight installed four Leffel turbines in their flour mill on Virginius Island, which together developed about 300 horsepower. All four turbines still remain in the ruins of the old flour mill. [Learn more about Virginius Island].

In 1859, the "American" turbine was introduced by the firm Stout, Mills & Temple of Dayton, Ohio. Water was admitted inward to the runner of this wheel through openings around the circumference of the wheel and then discharged downward. In about 1876, John B. McCormick, a Pennsylvania inventor, found that by adding spoon-shaped discharge sections to the bottom of a turbine's runner, he could extract more energy from water leaving the wheel. In 1884, the Globe Iron Works – formerly Stout, Mills & Temple – adopted McCormick's design and patented the "New American Turbine Water Wheel". The buckets of this turbine were lengthened and curved downward, increasing the bucket area subject to the pressure and reaction of the water. The power of this wheel, nearly identical in diameter to the 1859 "American" wheel, was almost doubled.

Using design innovations, new production techniques, and better materials, the "New American" turbine was both efficient and durable. The runner of the turbine, for instance, was comprised of a solid or continuous casting formed entirely in dry sand molds, without a bolt or rivet in any part of the wheel. "Fenders" or "gate guards," a patented ring and lever mechanism, and graduated chutes around the circumference of the wheel provided an efficient application of water to the runner, permitting each turbine to be started gradually and steadily without any damaging jolts to shafting, belting, and gearing.

In 1888, two vertical shaft "New American" turbines and six horizontal shaft "Special New American" turbines were installed in the Shenandoah Pulp Mill at Harpers Ferry. These turbines combined to develop 2,340 horsepower, dwarfing the power capabilities of all previous millsites at Harpers Ferry.

Falling water remained the primary source of power in America through most of the 19th century. The interruptions to factory work that resulted from variations in streamflow and occasional freshets were accepted as the price of using waterpower. But as the scale of manufacturing grew, production stoppages became increasingly costly. Coupled with the industrialization of America was the rise of steam power. Steam engines released entrepreneurs from their dependence on waterpower, and industry gradually moved away from the rivers. By 1870, steam horsepower actually led water horsepower in manufacturing by a ratio of about 52-48. Ten years later, in 1880, steam surpassed water as a power source both in power produced and in number of units. By 1899, waterpower comprised just 15 percent of all power produced for manufacturing in America.

Nonetheless, at Harpers Ferry waterpower endured well into the 20th century. Turbines powered machinery at the Shenandoah Pulp Company until 1935. At the Potomac Power Plant alongside the Potomac River, waterpower generated electricity until January 1991. [Learn more about the Potomac Power Plant].