Railroad Rules, Signalling, Operations:

North American Signaling

by Carsten S. Lundsten

SP-style ABS simulator added December 22, 2011
Pittsburgh & West Virginia signal aspects and indications added February 20, 2013


Specific signaling documents - new document added February 2013
Comments to This Document


Welcome to this site on the subject of North American railroad signaling. It is truly a broad subject and I indeed make no claim to cover it completely. This site is under constant development.

The purpose of this site is to explain how operational and safety rules interact with signaling systems to build an operational and safe railroad. One may find it odd that a European is putting together this web site. The explanation is of course that this European happens to be very interested in North American railroads, and since he also happens to be a signal engineer, the study of North American practices is quite logical.

Below is a series of links to my documents on North American signaling. The documents are on isolated topics and can be read more or less as stand-alone documents. For the reader interested in a more straightforward introduction to North American signaling, I recommend to start the tour at the basics of North American Signaling and Safety principles . For Europeans this introduction is really a must. Many North American practices are very different from European practices. Having spent several years of hard struggle getting to understand this, I finally realized that we Europeans tend to get "derailed" already on page 1 of the rule book. So, please start from the beginning with the basics of North American Signaling and Safety principles .

Thanks to all the helpful and knowledgeable people whose patience and persistence I owe a lot to (!), in particular dr. Mark D. Bej, BNSF locomotive engineer Peter M. Stronge and signal engineer Eugene Cranston.

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 - added December 22, 2011
     Absolute Permissive Block signaling
     AT&SF double track Automatic Block Signaling
     AT&SF "Flat Pair" single track Automatic Block Signalling

Signal Aspects and Indications
      Atchison, Topeka and Santa Fe, 1995
      Bessemer & Lake Erie Railroad, 1957
      Kansas City Southern, 1998
      Pittsburgh & West Virginia, 1953 - new February 20, 2013
      Southern Pacific, 1996
      Union Pacific, 1988

Comments, corrections and more information are very welcome. Email me at csl@email.dk


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