In 1941 the Smith-Putnam wind turbine, the world's first megawatt-size wind turbine, was connected to the local electrical distribution system on Grandpa's Knob in Castleton, Vermont, USA. It was designed by Palmer Cosslett Putnam and manufactured by the S. Morgan Smith Company. The 1.25 MW turbine operated for 1100 hours before a blade failed at a known weak point, which had not been reinforced due to war-time material shortages. It would be the largest wind turbine ever built until 1979.