Frequency Changing Station

The Frequency Changing Station in Spokane, Washington is a building listed on the National Register of Historic Places. It was built by the Spokane and Inland Empire Railroad in 1908 to house electrical equipment used by the electric railway. Power was generated at the Nine Mile Falls dam and transmitted to the Frequency Changing Station. The station provided direct current to the streetcar network within the city of Spokane. To provide power to the rail network outside Spokane, the station converted a portion of the power to alternating current and fed it to a series of electrical substations spaced about 15 miles (24 km) on the operating line. The substations then converted power back to direct current for the streetcars, but also sold power at 110 volts AC to the communities.

The main station houses four motor-generator sets, four 1250 kilowatt transformers, three 375 kilowatt transformers, and three 75 kilowatt transformers. The east wing of the station contained a 550-volt, 275-cell storage battery. All of this electrical equipment was removed around 1939, when the owning railroad sold the property.

The railroad connected the cities of Colfax, Washington and Moscow, Idaho to Spokane, and the electric railway figured heavily in the rapid development of the area where it passed.