This section covers the various circuit symbols used in the signal drawings, and the nomenclature used to describe them.

The majority of information for this page came from a book labeled Graphical Signal Symbols and Written Circuit Nomenclature, published by The Railway Educational Bureau in 1950, and written D. C. Buell.

This first section deals with the standard AAR abbreviations and nomenclature used in the labeling of relay drawings.  If you have ever tried to read a signal drawing, and can't make sense out of it, these "TLA's" should help you.

This section deals with symbols used on signal drawings.

Signals and Semaphores (prior to ~1950)

Searchlight and Color Light Signals (prior to ~1950)

Signals, Semaphores, & Smashboards

Signal Supports

Relays - DC & AC

Relay Contacts

Circuit Controller Contacts - Miscellaneous

Circuit Controller Contacts

Contacts Actuated By Switch Points, Derails, or Locking Connections

Other Signal & Pneumatic

Indicators, Locks, Buzzers, & Bells

Other Electrical Schematic Symbols

Railway Tracks & Highway Crossings

Buildings, Bridges, & Tunnels

Wayside Fixtures



Miscellaneous Devices Applied To Tracks

Pipe and Wire Lines

Lead-Outs, Bolt Locks, Cranks, and Deflecting Bars

New 6OCT2006, 26AUG2013
last Changed: 06-Sep-2019