ASME-Landmark:State Line Generating Unit 1


Dwarfing the typical electric-power generators of the day, the "State Line" turbine-generator, located on the Indiana-Illinois border, represented 14 percent of the entire Chicago metropolitan district when it was placed in commercial service on April 8, 1929. The Unit 1 turbine was the first unit to use five stages of feed-water heating, was the first to produce 650 pounds of pressure steam for electric generation, and was an original design in that the metal-enclosed generator bus is housed outdoors.

From 1929 to 1954 the Unit 1 turbine generator was the largest unit of its kind in the world. Its 208,000 kilowatt rating was 30 percent above the next largest unit at that time and was sufficient to light more than 100,000 average homes with all the lights in each house burning simultaneously.

In December of 1953 the Ohio Power Company's Muskingham #1 unit surpassed the "champ" with a rating of 213,000 kilowatt. In an industry which had doubled its output at less than ten-year intervals, a twenty-five-year reign represented a substantial engineering feat.

Although the plant continued to operate for years, Unit 1 was taken out of service in 1978—just one year after it was designated a National Historic Mechanical Engineering Landmark. In 2010, the State Line Power Plant was described as one of the greatest single contributors to the Chicago area's noncompliant status under the Clean Air Act. Rather than retrofit the plant with pollution controls, the firm that owned the State Line Power Plant closed it on March 31, 2012. Demolition began shortly thereafter. See ASME website for more information