Active North American railroad interlocking towers and cabins

December 31, 2003

This list of active railroad interlocking towers and cabins was originally compiled for the "Tower Tribute" section in the April, 1995 issue of TRAINS magazine.

The assistance of numerous people is gratefully acknowledged.

The list is organized alphabetically by state, with regional subgroupings as needed. A total of active interlockings follows the state or group heading. An italicized entry signifies a recent closure.

Additions and corrections

Corrections and updates may be sent via email. Alternatively, you may submit additional information by post to:

Jon Roma
P. O. Box 2155
Champaign, IL 61825-2155

NOTE: 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.

Definitions

• The facility must be a locally-controlled interlocking or block station, which excludes most dispatching offices. However, the list does include many facilities that control some remote locations in addition to the locally-controlled interlocking or block station.

• This interlocking or block station should be operated from a structure primarily devoted to this purpose. Buildings of more than one story are listed as towers; one-story free-standing buildings are listed as cabins. Interlockings or block stations located in a depot, yard office or similar facility are listed as offices. Yard facilities (such as hump towers) are listed only if the facility also controls main line switches and signals.

• A tower or cabin whose only function is to control movable bridges is included only if the facility controls signals (and possibly switches and derails). A number of manned movable bridges are operated locally but are interlocked with signals controlled remotely (i. e., by a dispatcher); the personnel staffing these bridges are generally considered bridgetenders and not operators. These facilities are not included.

Abbreviations denoting type of interlocking machine:
	E	electric (typically GRS model)
	EM	electro-mechanical (mechanical frame in conjunction with separate electrical levers interlocked electrically or mechanically with mechanical frame)
	EP	electro-pneumatic (typically US&S model)
	M	mechanical frame (old ``armstrong'' or ``strong-arm'' levers); presence of pipeline-operated switches, derails, or signals is indicated when known
	R	all-relay machine (includes CTC- and "NX"-type panels and other modern variants)
Abbreviations denoting type of building or structure:
	B	movable bridge cabin, on or next to bridge
	C	cabin
	O	office (e. g., in yard office or depot building)
	T	tower (building with two or more stories)