Wind Turbine on Grandpa's Knob, VT. Photo courtesy of Rutland Herald.
The first large-scale electricity-producing windmill (the world's largest at the time) was installed in 1941 at Grandpa's Knob, on the border of Castleton and West Rutland, VT, to take advantage of New England's strong wind energy regime. Several companies collaborated on the turbine: S. Morgan Smith of Pennsylvania financed the project; Palmer C. Putnam executed the design; and General Electric, the American Bridge Co., the Budd Co. and Wellman Engineering also participated. Among the electric companies declaring interest in the project was Central Vermont Public Service, whose president believed wind power to be the wave of the future.
Engineers hurried the prototype into production without a customary degree of testing to complete fabrication before parts became scarce due to the looming threat of war. A news release announcing commissioning suggested that wind power could play a role in securing the nation's electric facilities as the United States moved toward entering the war: "with an eye to national defense, they [engineers] also say that a series of such wind turbines, distributed through the hills, would be less vulnerable to air attack than equivalent generating capacity concentrated in a single station."
Installation of the 240-ton edifice on the nearly 2000-foot summit presented several challenges, the most serious of which was the 43-ton pintle girder rolling off its trailer while being pulled uphill around a hairpin turn, causing it to wedge in a rock crevasse. It took workers three weeks to free it.
After nearly two months of testing the 1,250-kW turbine atop the 110-foot tower, full operation generating electricity to the power grid commenced October 19, 1941. According to the Rutland Herald, "Over the next 18 months, the experimental wind turbine operated more than 1,000 hours. Engineers corrected various flaws in the system and made minor repairs of cracks in the blades. The blades churned out electricity in winds of 70 miles per hour and withstood gales of 115 mph. The eventual goal was to make the turbine a totally automatic operation requiring no on-site staff. In February 1943, wind generation ground to a halt as a main bearing failed. Since the country remained in the midst of war, a replacement part took more than two years to manufacture and install." The turbine restarted on March 3, 1945 and operated normally until March 26, when the turbine suffered a massive failure. One of the 75-foot blades suddenly snapped off and hurled 700 feet down the mountain, while the remaining blade (now off-balance) damaged the turbine tower. The failure was blamed on the lengthening of a concealed old crack at the root of the turbine blade. The experiment, still largely considered a success, ended with the turbine being razed in the summer of 1946.
Source: "Breezin' through History", an article published in the Rutland Herald According November 4, 2004. For more information, see Power from the Wind, by P. C. Putnam.
View a film clip of Smith-Putnam turbine in action.
History content contributors include Harley Lee of Endless Energy, James Manwell of the University of Massachusetts Renewable Energy Resource Laboratory, and Tom Gray of American Wind Energy Association. Edited by Bob Grace, Sustainable Energy Advantage, LLC.