Railway Signalling and Operations FAQ

Railway Signalling and Operations FAQ

[ Note to Contributors | Copyright & Licensing agreement ]


This FAQ is still in its infancy and incomplete. Several people have contributed to it in greater or lesser degrees; their help is acknowledged on the various pages.

The Basic Section is a general overview of signalling on a simplified level. If you are unfamiliar with railroad signalling, this is the section for you. The Advanced Section covers more "stuff", and each item is covered in more detail.

There exists a very strongly "circular" interrelationship among all of this information, making it difficult to separate many concepts entirely. More than one read-through may be needed for a full understanding.

Disclaimer & Caveant Lectores

Table of Contents

Basic Section

  1. Introduction
    1. Reason for signalling
    2. Principles of operation

  2. Overview of Operating Appliances
    1. Track, Track Designations
    2. Switches
    3. Blocks
    4. Interlockings
    5. Signals

  3. Overview of Operating Practices
    1. Blocks (rough)
    2. Manual Block & Block Towers
    3. Automatic Blocks & Signals
    4. Interlockings
    5. Centralized Traffic Control
    6. see also links under Railway Signalling Index Page [author?]

    Advanced Section

  4. Operating Practices
    1. Operating Authority
    2. Timetable Operation
      1. Timetables
      2. Superiority: of Class, Right, and Direction
      3. Difficulties when speed of communication = speed of travel

    3. Block System Operation in General
      1. Absolute Block, Permissive Block
      2. Permissive Block
      3. Block Line, Telegraphy
      4. Block Sheet
      5. in Manual Block territory
      6. in Automatic Block territory

    4. Train Order Operation
      1. Example of NORAC Form D

    5. Manual Block Operation
      1. Block Stations
      2. Token/staff systems
      3. Train Order systems
      4. Block Instrument systems
        1. Block Working in Britain
        2. Manual Block Working in Germany [Joern Pachl]
      5. Signalled systems

    6. Automatic Block Operation
      1. Simple automatic block
      2. Controlling trains in ABS
      3. The "Riding the Yellows" Problem
      4. Automatic Block Rules
      5. Placement of signals, effect on operations
      6. U.S. FRA Delay in Block Rule [Amtrak]
      7. See also "Absolute-Permissive Block", below.
      8. ABS-only control: generalized example of ABS on AT&SF [Carsten Stjernholm Lundsten]
      9. Example of ABS on Southern Pacific [Carsten Stjernholm Lundsten]
      10. ABS plus Interlocking Rules: generalized example of ABS on PRR
      11. Diagram of actual Eastern US ABS trackage

    7. Absolute-Permissive Block
      1. General
      2. General example of APB
      3. Description of APB [Carsten Stjernholm Lundsten]

    8. Interlocking Operation
      1. Interlocking Rules
      2. Signalling Styles (Route vs. Speed)
      3. Signal types and placement
      4. Plant arrangement
      5. Automatic Interlockings
      6. Overlaps
      7. Approach locking
      8. Route locking
      9. Signal timeouts
      10. Passing signals at Stop
      11. Interlocking Maps
      12. Narrative: operating an interlocking in Automatic Block territory (U.S.)
      13. PRR Contingencies: a summary of how contingencies were handled at interlockings and similar control points on PRR.

    9. Traffic Control System / Centralized Traffic Control
      1. Diagram of actual TCS trackage

  5. Operating Documents and Documentation
    1. General Principles; Types of Operating Documents

    2. Rules and Rulebooks - General
      1. General principles
      2. Implementation by railroad

    3. Full text of rulebooks on the Web
      1. PRR - Pennsylvania Railroad
      2. CROR - Canadian Rail Operating Rules
        • (Available from Railway Association of Canada, 800 René Levesque Boulevard West, Suite 1105, Montréal, Québec H3B 1X9, (514) 879-8555).
      3. CCOR - Consolidated Code of Operating Rules [Joseph Anderson] (?status)
        • Part 1 [dead link]
        • Part 2, Rules 1-34 [dead link]
      4. GCOR - General Code of Operating Rules
      5. Sikkerhetsreglement Norges Statsbaner, Norwegian State Railways Book of Rules (in Norwegian, of course)
      6. Junaturvallisuussääntö, Finnish Railways Book of Rules (in Finnish)
      7. Netherlands railway signal rules

    4. Employee Timetables and Special Instructions - General
      1. General principles
      2. Relationship to public timetables
      3. Example of internal ETT structure
      4. Conrail Employee Timetable -- an example of portions, primarily station pages, of one US railroad's employee timetable

    5. Full text of employee timetables on the Web

  6. Operating Personnel
    1. Train Personnel
      1. Engineman
      2. Brakeman
      3. Conductor

    2. Dispatching/Operating Personnel
      1. Leverman
      2. Operator
      3. Train Director
      4. Dispatchers

    3. Supervisory Personnel
      1. Trainmaster
      2. Rules Examiner
      3. Superintendent

  7. Operating Appliances
    1. Track
      1. Gauntlet track
      2. Switches/turnouts: sizes, speeds, part names, etc.
      3. Derails
      4. Electric locks
      5. Tunnels, bridges
      6. Track classes, U.S. - get document 49CFR213 from this Federal site.

    2. Relays
      1. Type, etc.
      2. Wiring considerations: falling, etc.
      3. Wiring nomenclature

    3. Track Circuits
      1. General
      2. Coded track signals
      3. Electrical connection of switches/derails to signal system
      4. Considerations when grade crossings involved.
      5. With electric locomotives
      6. With RR crossings at grade
      7. Example circuits

    4. Hand and Lantern Signals
    5. Whistle signals
    6. Fixed (Wayside/Lineside) Signals by Style (hardware)
      1. Old / Obsolete Fixed Signals
      2. Semaphore Signals
        1. List of active semaphore signals in U.S. [off site, Eric Schmelz]
      3. Color Light Signals: US
      4. Position Light Signals
      5. Color Position Light Signals
      6. Rare / Unusual Installations
        1. PRR Tombstone Signals: -1- -2-
      7. Significance of Signal Components (N. America)

    7. Fixed (Wayside/Lineside) Signals by use
      1. Block and interlocking signals [needed?]
      2. Train Order Signals
      3. Yard Signals
      4. Doll arms
      5. Train maintenance signals
      6. Block limit signals
      7. Signs (various)
      8. Other

    8. Signal Symbols
      1. Diagramming Signals (Unfinished.)
      2. Signal Symbols [PRR]
      3. PRR signal symbols, gathered and edited by Hank Sundermeyer

    9. Signal Aspects and Their Meaning -- General
    10. North America
      1. Learning the [typical U.S. Color Light] Aspects
      2. Forms of Color-Light Signals (N. America)
      3. Forms of (Color-)Position-Light Signals (N. America)
      4. Summary of Speeds Required by Signal Aspects
      5. Signal Aspect Concordance
      1. Aspect guide, Henning Makholm

    11. Signal Aspects and Their Meaning -- By Common Rule Organization
      1. CROR - Canadian Rail Operating Rules
      2. GCOR - General Code of Operating Rules
      3. NORAC - Northeast Operating Rules Advisory Committee
      4. UCOR - Uniform Code of Operating Rules semaphore signals [R. G. Burnet]
        Canadian semaphore signals, as derived from the 1940 UCOR.
      5. UCOR - Uniform Code of Operating Rules [rrrobbie@idirect.com - searching for name]
      6. Semaphore Color-light
        This site also contains interesting information on telegraphy.

    12. Signal Aspects and Their Meaning -- By Individual Railroad
      1. Baltimore & Ohio RR
        See also Baltimore and Ohio Railroad Color-Position Light Signals [Mike Calo]
        Same site also has pictures of B&O signals.
      2. Boston & Maine RR
      3. Chesapeake & Ohio
        also Railroad Signals Explained
      4. Chicago, Rock Island & Pacific RR SOON!
      5. Erie RR SOON!
      6. New York Central
      7. Monongahela RR SOON!
      8. New York, New Haven & Hartford RR SOON!
      9. Pennsylvania RR
      10. Richmond, Fredericksburg & Potomac
      11. Seaboard Coast Line
      12. Southern RR
      13. Wisconsin Central RR

    13. Cab Signals
      1. Locomotive Cab Appliances
      2. Lineside Appliances
      3. Operational Implementation

    14. Blocks and Block Stations ("Towers")
      1. Placement
      2. Design
      3. Call letters
      4. Forms
      5. Appliances
      6. Tower site, Peter Thompson [off site]

    15. Interlockings and Interlocking Stations ("Towers")
      1. Placement
        1. List of active interlocking towers and cabins in the United States and Canada [Jon Roma]
      2. Design
      3. Call letters
      4. Forms
      5. Appliances
      6. Examples
        1. Railroad Places That Are No More, on The Signal Maintainer's Shack site. [Doug]

    16. Interlocking Machines
      1. Model Boards
        1. Model Boards (Unfinished.)
        2. Photos of a British signal box
      2. Strong-arm installations
      3. US&S Electro-pneumatic machines
      4. GRS ...
      5. GRS cTc machines
      6. CAD: Computer Assisted Dispatching

    17. Communications
      1. Block Line
      2. Radio
      3. North American Railroad Radio Frequencies [Jon Roma]

  8. Law
    1. United States
      1. U.S. Code, Title 45: Railroads
      2. U.S. Code, Title 49: Transportation; Subtitle V: Rail Programs
      3. Code of Federal Regulations, Title 49

  9. Reference
    1. A signalling bibliography [Andrew Waugh]
    2. A Glossary of Signalling-Related Terms
    3. US Railroads
    4. A short description of U.S. railroad acronyms, geographic locations, and traffic patterns, possibly useful in the understanding of other material on this site.

  10. General Links to Other Sites
  11. (Topic-specific links appear in the sections above.)

    1. General
      1. Railway Technical Web Pages
        Much on operations; a glosary; links to many sites.

    2. North America
      1. Signalling pages ... [James Sterbenz]
        A wellspring of information on railroad signalling worldwide.

      2. New York City Subway Signalling
        Bernard S. Greenberg

      3. [U.S.] NMRA Sig SIG
        National Model Railroad Association
        Signaling Special Interest Group's page. Currently (6/97) contains listings of their newsletter, the Clear Block, and links to other signal-related sites. The newsletter is very good and is actually primarily about prototype practice.

      4. Railroad signal quiz

      5. Paul Caniff

      6. HALEY (Indiana) Tower

      7. Running a locomotive
        Select Pictures, then Railroads, then the locomotive console.
        Not signalling per se, but provides some idea of what one does in response to signals.

      8. Lundsten's Basement

      9. US locking tables, Andrew Waugh. PDF format, 347K (98 pp.).

    3. Western Europe
      1. Clive D. W. Feather has some British interlocking maps.

      2. The Signal Box
        A site about British sigalling, signal boxes, etc. Signal quiz.

      3. British signalling information pages

      4. Exeter panel box, Phil Bellamy.

      5. German/Bavarian signals
        Includes streetcar signals which occasionally governed 'normal' trains.

      6. TGV signalling.
        Expired links: http://whirligig.ecs.soton.ac.uk/~db93/tgv/tgvsignals/tgvisignals.html and ...tgvsignals/tvm430.html.

      7. German Railway Signal Systems
        Wolfgang A. Meyenberg.

      8. The new train control section [SBB]
        showing a train control (dare I call it dispatching?) console on the Swiss National Railway.

      9. Netherlands Railway signal rules

      10. Classical dutch railwaysignals [Niels Karsdorp]

      11. Danish signalling

      12. Lundsten's Basement

      13. Sikkerhetsreglement Norges Statsbaner (Norway)

      14. Junaturvallisuussääntö (Finland)

      15. Rhaetische Bahn [Dr. Christoph Ozdoba]

      16. Portuguese Railways Signalling [Hugo Leandro]

      17. Austrian signalling

    4. Eastern Europe
      1. Hungarian signals and signs

    5. Far East
      1. Railfan Web page
        Hiroshi Naito. Includes pictures of Japanese color-light and dwarf signals.

  12. Links to Related Commercial Sites
  13. N.B.: Listing herein does not necessarily indicate endorsement thereof.

    1. NORAC Signal Demo Program -- a ZIP file.
      (old version)
      Demo version of program (limited selection, no multimedia) available for download from CybeRail. Requires Windows; to install, copy demosigs.exe to your hard drive, then select Run... from the File menu, type in demosigs, answer a few simple questions, and run the demo. Only minor irritant is program's propensity to "drop" an aspect onto the first signal head -- make sure you drag through the grey area of the window.

    2. Bluebell [UK] Railway Signalling and Signal Boxes

    3. Unique shopping mall
      Site mentions plans to have (?full size) crossing signals for sale soon.

  14. Not Yet Organized Links
    1. http://www.csinet.net/candcb/
      C&C Barneyback candcb@csinet.net

    2. http://www.internetcashplanet.com/railroadtowers/Default.htm

  15. Signalling for Model Railroading
  16. Personal and commercial sites included. N.B.: Listing herein does not necessarily indicate endorsement thereof.

    1. Richard Toplan's stuff about signalling for models.

    2. TracTronics

    3. Tayden Design, Inc., Webster, Mass.; Regan Wyckoff
      Produce software for model RR control named Train Trek [TM].

    4. Logic Rail Technologies, Houston, Tex.; Chuck Stancil
      A manufacturer of electronic products for model railroads; main products are signaling circuits. Web site hosts a brief tutorial.

    5. RR-CirKits; Dick Bronson

    6. Electronic Design & Railway Telemetry
      Development, production and design of high quality electronic communication software, asset and employee tracking and railway telemetry systems.

Mark's Railroad-Related Stuff
Railroad Books of Rules and Signalling: A Home Page
Signalling FAQ

Mark D. Bej
+1 216-444-0119