This list and the information contained therein may be freely reproduced or used in printed or electronic form for non-commercial purposes, provided the source is acknowledged and provided that such publication also refers readers to the original list on this site.
The original version of this list of active North American railroad interlocking towers and cabins was originally compiled for the “Tower Tribute” section in the April 1995 issue of TRAINS magazine by then-Senior Editor J. David Ingles, with help from the following people:
Jerry Angier, John Arbuckle, Byron Babbish, Mike Blaszak, C. S. Burgess, Terry Chicwak, B. B. Cyrus, Dale DeVene Jr., Jim Ehernberger, Lee Gregory, Norm Herbert, S. R. Johnson, Lyle Key, Chris Knapton, Blair Kooistra, John Krattinger, Jim Latimer, John Lucas, Paul Meyer, Dan Munson, David Oroszi, D. G. Orr, R. D. Owens, Mike Palmieri, David Patch, E. G. Peterson, Louis Saillard, Bill Schafer, Dick Schmeling, Lou Schmitz, Joe Slauser, Frank Tatnall, George Werner, and Pete White.
The assistance of these people is gratefully acknowledged.
Each list is organized alphabetically by state, with regional subgroupings as needed. In most cases, the railroad controlling (and staffing) each tower is named first within the list of railroads involved in the plant.
A total of active interlockings follows the state or group heading. Recent closures are noted by highlighting.
Additions and corrections to this list are welcome. We'd be glad to hear about omissions and would appreciate learning about tower closings so we can update this list.
Additional details (e. g., type and size of control machine(s) and historical or operational data) are welcome.
Corrections and updates may be sent via email.
Entries included must meet the following criteria:
|Machine type symbols:|
|E||Electric (typically GRS model machine).|
|EM||Electro-mechanical. This type of machine has a mechanical frame with separate electrical levers that are either electrically or mechanically interlocked with mechanical frame.|
|EP||Electro-pneumatic (typically US&S model machine).|
|M||Mechanical frame (old “armstrong” or “strong-arm” levers). The presence of pipeline-operated switches, derails, or signals is indicated when known.|
|R||All-relay machine. Includes CTC- and “NX” or “UR”-style panels, as well as other more modern variants that lack mechanical locking.|
|Structure type symbols:|
|B||Movable bridge cabin, on or next to bridge.|
|C||Cabin (one-story free-standing building).|
|O||Office (e. g., yard office or depot building).|
|T||Tower (building with two or more stories)|