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GCOR - Glossary

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Use only the following abbreviations:

ABS       Automatic Block Signal System
ACS       Automatic Cab Signal System
AMK       Amtrak
ATC       Automatic Train Control
ATS       Automatic Train Stop
AUTH      Authority
BRN       Branch
BRT       Block Register Territory
c         Center
C&E       Conductor and Engineer
COFC      Container on Flat Car
CONDR     Conductor
CP        Control Point
CTC       Centralized Traffic Control
DISPR     Dispatcher
DIST      District
DIV       Division
DT        Double Track
DTC       Direct Traffic Control
E         East
ENG       Engine
ENGR      Engineer
ESS       East Siding Switch
EWD       Eastward
FRT       Freight
HER       Head End Restriction
im        Intermodal
JCT       junction
MAX       Maximum
MMT       Multiple Main Track
MP        Mile Post
MPH       Miles Per Hour
MT        Main Track
mw        Maintenance of Way
N         North
NO        Number
NSS       North Siding Switch
NWD       Northward
OK        Correct
OPR       Operator
ORIG      Originating
PSGR      Passenger
RC        Radio Channel
RECD      Received
REG       Region
s         South
SDG       Siding
sss       South Siding Switch
SUB       Subdivision
SUBDIV    Subdivision
SUPT      Superintendent
SW        Switch
SWD       Southward
TOFC      Trailer on Flat Car
TRK       Track
TRN       Train
TWC       Track Warrant Control
w         West
wss       West Siding Switch
wvm       Westward
xo        Crossover
YL        Yard Limits
YM        Yardmaster

Use the normal abbreviations for names of months.

       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.

       See Automatic Cab Signal System.

       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

Automatic Cab Signal System (ACS)
       A system that allows cab signals and the cab warning
       whistle to operate automatically.

Automatic Train Stop System (ATS)
       A system activated by wayside inductors positioned
       to apply the brakes automatically until the train stops.

       A length of track between consecutive block signals
       or between a block signal and the end of block system

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

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.

       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.


       Railroad cars.

Centralized Traffic Control (CTC)
       A block system that uses block signal indications to
       authorize train movements.

       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.

Crossings at Grade
       Crossings that intersect at the same level.

       A track connection between two adjacent tracks.

       See Centralized Traffic Control.

Current of Traffic
       The movement of trains in one direction on a main
       track, as specified by the rules.

Direct Traff ic 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 govems 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.

       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.

       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.

       Also includes student engineers, firemen, and

      Railroad equipment.

Fixed Signal
       A signal that is fixed to a location permanently and
       that indicates a condition affecting train movement.

       Any employee providing flag protection.

      Employee in charge of work.

       Signal appliances that are interconnected so that each
       of their movements follows the other in a proper
       sequence.  Interlockings may be operated manually or

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.

       Railroad employees.

Multiple Main Tracks
       Two or more main tracks that are used according to
       the timetable.

       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.

Reverse Movement
      A movement opposite the authorized direcfion.

       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

Special Instructions
       Instructions contained in the timetable or other

Spring Switch
       A switch with a spring mechanism that retums the
       switch points to the original position after they are
       trailed through.

       A place designated by name in the timetable station

Switch Point Indicator
       A light type indicator used during movement over
       certain switches to show that switch points fit

       A publication with instructions On train, engine, or
       equipment movement.  It also contains other essential

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.

       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.

       Conductors, assistant conductors, brakemen, yard
       engine foremen, switchmen, and yard helpers.

       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 posifion they were forced.

       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

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