These definitions have been updated to the 7th Edition of GCOR Effective April 1, 2015. Click Here for the Update
Below are the Definitions showing in the 6th Edition of GCOR Effective April 7, 2010.
ABS
See Automatic Block Signal System.
Absolute Block
A length of track that no train is permitted to enter while the track is occupied by another train.
Absolute Signal
A block or interlocking signal without a number plate, or designated by an A marker.
ACS
See Automatic Cab Signal System.
Articulated
Permanently connected multiple unit cars that share a common truck.
ATC Actuator
An ATC brake applying apparatus.
ATS
See Automatic Train Stop System.
Automatic Block Signal System (ABS)
A series of consecutive blocks governed by block signals, cab signals, or both. The signals are activated by a train or by certain conditions that affect the block use.
Automatic Cab Signal System (ACS)
A system that allows cab signals and the cab warning whistle to operate automatically.
Automatic Train Control (ATC)
A system to enforce compliance with cab and wayside signal indications. If the train exceeds a predetermined speed for a given signal indication and speed is not reduced at a sufficient rate, brakes are automatically applied.
Automatic Train Stop System (ATS)
A system activated by wayside inductors positioned to apply the brakes automatically until the train stops.
Block
A length of track:
• between consecutive block signals.
• between a block signal and the end of block system limits.
or
• in ATC limits the use of which is governed by cab signals and/or block signals.
Block Register Territory (BRT)
A method of operation in non-signaled territory where trains, men, and equipment are authorized to occupy the main track in limits designated by the timetable.
Block Signal
A fixed signal at the entrance of a block that governs trains entering and using that block.
Block System
A block or series of consecutive blocks within ABS, ACS, CTC, or interlocking limits.
BRT
See Block Register Territory.
Cab Signal
A signal in the engineer’s compartment or cab that indicates a condition affecting train movement. Cab signals are used with interlocking or block signals or without block signals.
Cars
Railroad cars.
Centralized Traffic Control (CTC)
A block system that uses block signal indications to authorize train movements.
Clearance Point
The location closest to a switch where it is safe for equipment, and a person riding the side of equipment unless prohibited, to pass equipment on an adjacent track.
Conductor
Employee in charge of train or yard movement.
Control Operator
Employee assigned to operate a CTC or interlocking control machine or authorized to grant track permits.
Control Point
The location of absolute signals controlled by a control operator.
Controlled Siding
A siding within CTC or interlocking limits where a signal indication authorizes the siding’s use.
Controlled Signal
An absolute signal controlled by a control operator.
Crew Member
Conductors, assistant conductors, brakemen, engineers, remote control operators, yard engine foremen, switchmen, and yard helpers.
Crossings at Grade
Crossings that intersect at the same level.
Crossover
A track connection between two adjacent tracks, consisting of two switches, which is intended to be used primarily for the purpose of crossing over from one track to the other.
CTC
See Centralized Traffic Control.
Current of Traffic
The movement of trains in one direction on a main track, as specified by the rules.
Direct Traffic Control (DTC)
A DTC block or a series of DTC blocks where the train dispatcher authorizes track occupancy.
Distant Signal
A fixed signal outside a block system that governs the approach to a block signal, interlocking signal, or switch point indicator. A distant signal does not indicate conditions that affect track use between the distant signal and block or interlocking signals or between the distant signal and switch point indicator. A distant signal is identified by a D.
Double Track
Two main tracks where the current of traffic on one track is in a specified direction and in the opposite direction on the other.
Dual Control Switch
A power-operated switch, moveable point frog, or derail that can also be operated by hand.
DTC
See Direct Traffic Control.
DTC Block
A length of main track specified by name. DTC block name and limits are identified by wayside signs reading, Begin (name) Block and End (name) Block and by mile post location in the timetable.
Electric Switch Lock
An electrically controlled lock that restricts the use of a hand-operated switch or derail.
Engine
A unit propelled by any form of energy or more than one of these units operated from a single control. Engines are used in train or yard service. Rules that apply to engines also apply to cab control cars.
Engineer
Also includes student engineers, firemen, hostlers, and remote control operators.
Equipment
Railroad equipment.
Equipment Fouling a Track
The end of rolling equipment or on-track maintenance of way equipment left between the clearance point and the switch points leading to the track on which the equipment is standing.
Fixed Signal
A signal that is fixed to a location permanently and that indicates a condition affecting train movement.
Flagman
Any employee providing flag protection as outlined in Rule 6.19 (Flag Protection) and for other purposes as outlined in the rules.
Foreman
Employee in charge of work.
Interlocking
Signal appliances that are interconnected so that each of their movements follows the other in a proper sequence. Interlockings may be operated manually or automatically.
Interlocking Limits
The tracks between outer opposing absolute signals of an interlocking.
Interlocking Signals
The fixed signals of an interlocking that govern trains using interlocking limits.
Main Track
A track extending through yards and between stations that must not be occupied without authority or protection.
Men or Equipment
A term referring to Engineering Department employees and their related equipment.
Multiple Main Tracks
Two or more main tracks that are used according to the timetable.
Pilot
An employee assigned to a train to assist an engineer or conductor who is unfamiliar with the rules or the portion of railroad the train will operate on.
Proceed Indication
Any block signal indication that allows a train to proceed without stopping.
Radio
As used in these rules it also applies to wireless communication devices when used in railroad operation.
Radio Blocking
A method to establish an absolute block for a following train in non-signaled territory by direct communication with a preceding train.
RCO
See Remote Control Operator
RCZ
See Remote Control Zone
Remote Control Operator (RCO)
An employee who may operate an engine with or without cars by means of a remote control transmitter.
Remote Control Transmitter
A device that gives the remote control operator control of a remote control engine.
Remote Control Zone (RCZ)
A portion of track(s) within definite limits designated in the timetable special instructions.
Reverse Movement
A movement opposite the authorized direction.
Siding
A track connected to the main track and used for meeting or passing trains. Location of sidings are shown in the timetable.
Signal Aspect
The appearance of a fixed or cab signal.
Signal Indication
The action required by the signal aspect.
Single Track
A main track where trains are operated in both directions.
Special Instructions
Instructions contained in the timetable or other publication.
Spring Switch
A switch with a spring mechanism that returns the switch points to the original position after they are trailed through.
Station
A place designated by name in the timetable station column.
Switch Point Indicator
A light type indicator used during movement over certain switches to show that switch points fit properly.
Timetable
A publication with instructions on train, engine, or equipment movement. It also contains other essential information.
Track Bulletin
A notice of conditions affecting train movement. It may also authorize movement against the current of traffic where Rule 9.14 (Movement with the Current of Traffic) is in effect.
Track Occupancy Indicator
An indicator that tells whether a length of track is occupied or not.
Trackside Warning Detector
A device that indicates conditions such as overheated journals, dragging equipment, excess dimensions, shifted loads, high water, or slides.
Track Warrant Control (TWC)
A method to authorize train movements or protect men or machines on a main track within specified limits in a territory designated by the timetable.
Train
One or more engines coupled, with or without cars, displaying a marker, and authorized to operate on a main track. A term that when used in connection with speed restrictions, flag protection, and the observance of all signals and signal rules also applies to engines.
Train Coordination
Working limits established by a roadway worker through the use of a train’s authority on a main track or other track where specific authority is required from a control operator or train dispatcher.
TWC
See Track Warrant Control.
Variable Switch
A switch identified by a V or a bowl painted yellow. When trailed through, the switch points remain lined in the position they were forced.
Whistle Quiet Zone
A designated portion of track, that includes road crossing(s) at grade where whistle signal (7) is not regularly sounded.
Working Limits
A segment of track within definite boundaries on which movements may be made only as permitted by the employee in charge. Boundaries may be established using mile posts, station signs, timetable locations, or clearly identifiable points.
Yard
A system of tracks, other than main tracks and sidings, used for making up trains, storing cars, and other purposes.
Yard Limits
A portion of main track designated by yard limit signs and timetable special instructions or a track bulletin.