Near Union in McHenry County, Illinois — The American Midwest (Great Lakes)
Spaulding Tower / Towers and Interlocking Plants
For over 90 years, this classic Midwestern interlocking tower protected the junction of the Milwaukee Road and the Elgin, Joliet & Eastern at Spaulding, just east of Elgin, Illinois.
Originally built around 1890 when the EJ&E extended north toward Waukegan, the tower was expanded to its present size when the Milwaukee Road added a second main and a yard lead in 1909. It housed a 36-lever hand-operated interlocking machine to control all of the track switches and signals at Spaulding. The junction was converted to centralized control and the tower closed in the 1980's.
Spaulding Tower was donated to IRM in 1988 by the EJ&E and by Metra and the Soo Line, which took over the Milwaukee Road route after the line's bankruptcy. IRM volunteers dismantled the huge interlocking machine before the upper story of the building was cut off, and both halves were moved by truck to Union. IRM crews reassembled the building and restored it to its 1950's appearance.
Towers and Interlocking Plants
Where railroads cross at the same level
At one time, nearly every junction had an adjacent tower housing an operator. The tower operators controlled the track switches and signals governing the route of each train through the junction. The controls were "interlocked" to prevent potential conflicts; if one train was given a "Clear" signal, the controls physically prevented a "Clear" indication on any opposing route. Early towers had a series of large mechanical "Armstrong" (hand-thrown) levers, whose motion when thrown was transmitted by a series of moving rods to change the position of track switches. Modern interlocking plants used electric or pneumatic power rather than hand-thrown levers.
By the late 1900's, manned towers had nearly disappeared except at busy urban terminals. Today, a dispatcher who may be hundreds of miles away can control all switches and signals electronically.
Erected by Illinois Railway Museum.
Topics. This historical marker is listed in this topic list: Railroads & Streetcars. A significant historical year for this entry is 1890.
Location. 42° 13.779′ N, 88° 31.735′ W. Marker is near Union, Illinois, in McHenry County. Marker and tower are about 100 feet northwest of the entrance to the Illinois Railway Museum Touch for map. Marker is at or near this postal address: 7000 Olson Road, Union IL 60180, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. The Elgin & Belvidere Electric Company/Rebirth of the Elgin & Belvidere (about 300 feet away, measured in a direct line); 1851 Marengo Station (about 500 feet away); Indiana Harbor Belt 1181 (about 500 feet away); Simplex Type Automatic Coupler (about 600 feet away); Couplers (about 600 feet away); Railroad Brakes / Westinghouse Automatic Air Brakes (about 600 feet away); Railroad Standard Time (about 600 feet away); Chicago Railways Company Date Stone (about 600 feet away). Touch for a list and map of all markers in Union.
Also see . . .
1. Interlocking Towers, Protecting "Blocks" Of Railroad. American Rails entry (Submitted on December 24, 2010, by William Fischer, Jr. of Scranton, Pennsylvania.)
2. Illinois Railway Museum. Museum website (Submitted on January 22, 2021, by Larry Gertner of New York, New York.)
3. IRM Spaulding Tower Webcam. (Submitted on December 24, 2010, by William Fischer, Jr. of Scranton, Pennsylvania.)
Credits. This page was last revised on January 22, 2021. It was originally submitted on December 24, 2010, by William Fischer, Jr. of Scranton, Pennsylvania. This page has been viewed 845 times since then and 17 times this year. Photos: 1, 2, 3. submitted on December 24, 2010, by William Fischer, Jr. of Scranton, Pennsylvania.