The Ohio Edison Mad River power plant in Springfield, Ohio was opened on October 2, 1927 and was dubbed “The Giant of the Miami Valley.” Designed by Springfield architect William K. Shilling, the power plant was located at the confluence of Buck Creek and the Mad River.
“Picture, if you can, a column of horses suddenly shot out from the High St. office of The Ohio Edison Co., four horses wide and 6,700 horses long. The work done by this mass of horses, four wide and approximately nine miles long, would represent in the popular mind 36,800 horsepower. This is the capacity of the new 20,000 kilowatt General Electric steam turbine installed in the company’s new Mad River generation station.”
-Springfield Daily News, October 2, 1927
The coal arrived on railroad cars and was sent into a crusher, which was then taken via a conveyor to the top of the power plant. From there, the coal was dumped into hoppers to pass under powerful magnets to remove bolts and other metal impurities before being crushed to powder and blown into a furnace. Air heated to 700 degrees Fahrenheit to achieve maximum efficiency was shot into the furnace at the same time. Internal furnace temperatures approached 2,500 degrees Fahrenheit. Water for the 70-foot high boilers were taken from the Mad River, which was purified and then heated to 700 degrees Fahrenheit at 400 pounds per square inch. Generators added later heated the steam to 900 degrees Fahrenheit and 800 pounds per square inch. The steam from the three boilers were used to drive the turbines to produce electricity.
The turbine was activated by high pressure steam, directed by nozzles against the blades mounted on the turbine shaft which spun at 3,600 revolutions-per-minute, or 825 miles-per-hour. Attached to the shaft of the turbine was a rotor spinning at the speed of the turbine. Electricity was produced when the rotor turned inside sets of heavy coils of copper wire, which produced a current that sent electricity out at 12,500 volts to an adjoining substation, where transformers boosted it to 69,000 volts for transmission via power lines. A condenser, which used untreated water from the Mad River, was taken in to cool the steam back into nearly pure water which was then fed into the boilers. This created a downward vacuum that helped maintain the flow in the boiler system.
In 1939, a 20,000-kilowatt generator was added, which was followed up with a third unit in 1950. At some point, the building was physically expanded and a 280-foot central stack was constructed.
On May 23, 1973, Ohio Edison was ordered by the federal Environmental Protection Agency to cease any air emission at the Mad River facility by June 24, an order that came after the Ohio Environmental Protection Agency denied four variances for pollution that were sought by Ohio Edison. The state noted that the company failed to submit an approvable compliance schedule to stay within state and federal air regulations. All emission sources, according to the state, must be in compliance by July 1975. Ohio Edison repeatedly requested a variance to continue to operate the non-compliant boilers until 1978. The Mad River plant, which provided power for approximately 33% of Springfield, was supposed to be closed on June 24, but variances were granted until 1981.
Demolition on the Mad River plant began in July 2010 and was completed later in the year. During the demolition process, the tower was toppled – but undetected cracks left the tower falling in the wrong direction. The stack, which was expected to fall to the east, crashed to the southeast taking down a building housing backup generators and two 12,500-volt power lines. After the demolition was complete, a few generating units for peak use and a substation were left behind on the 45-acre site.