Railroad Rules, Signalling, Operations:

North American Signaling

by Carsten S. Lundsten.

Western Maryland signal aspects and indications added December 26, 2016
Illinois Central Cab Signal based Absolute Permissive Block Signaling added October 18, 2017

North American Signaling documents

     Basics of North American Signaling and Safety principles
     Basic principles of Automatic Block Signaling, Interlocking, Traffic Control Systems and Centralized Traffic Control

Track Occupancy Control Systems
     Track Warrant Control (TWC)
     Direct Traffic Control (DTC)

Automatic Block Signaling systems
     Southern Pacific single track Automatic Block Signaling
            Simulator for SP-style ABS on the Central Oregon & Pacific
     Absolute Permissive Block signaling
            Illinois Central Cab Signal based Absolute Permissive Block Signaling - new October 18, 2017
     AT&SF double track Automatic Block Signaling
     AT&SF "Flat Pair" single track Automatic Block Signalling

Centralized Traffic Control systems
     Pittsburgh & West Virginia "Poor Man's CTC"

Signal Aspects and Indications
      Atchison, Topeka and Santa Fe, 1995
      Bessemer & Lake Erie Railroad, 1957
      Kansas City Southern, 1998
      Pittsburgh & West Virginia, 1953
      Southern Pacific, 1996
      Union Pacific, 1988
      Western Maryland, 1973 - added December 26, 2016

Comments, corrections and more information is very welcome. Please use this contact form


Text, Images except for wallpaper, HTML: Carsten S. Lundsten.
Wallpaper photo: Kindly by Eric Schmelz, modified by Carsten S. Lundsten