Union Pacific GCOR Terms and
Definitions
Automatic Block Signal System - answer 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.
Absolute Block - answer A length of track that no train is permitted to enter while the
track is occupied by another train
Absolute Signal - answer A block or interlocking signal without a number plate or
designated by an A marker
Adjacent Track - answer Parallel tracks that are not separated by a single lane roadway
or similar distance; only applies if Track Breach Protection is required
Articulated - answer Permanently connected multiple unit cars that share a common
truck
Automatic Train Control Actuator - answer An ATC brake applying apparatus
Automatic Cab Signal System - answerA system that allows cab signals and the cab
warning whistle to operate automatically
Automatic Train Control - answerA system to enforce compliance with cabin signal
indications. If the train exceeds a predetermined speed for a given cab signal indication
and speed is not reduced at a sufficient rate, brakes are automatically applied.
Automatic Train Stop Systems - answerA system activated by wayside inductors
positioned to apply the brakes automatically until the train stops
Block - answerA length of track: between consecutive block signals, between a block
signal and the end of block system limits, or in automatic train control limits, the use of
which is governed by cab signals and/or block signals
Block Register Territory - answerA method of operation in non-signal territory where
trains, men, and equipment are authorized to occupy the main track in limits designated
by the timetable
Block Signal - answerA fixed signal at the entrance of a block that governs trains
entering and using that block
, Block System - answerA block or series of consecutive blocks within ABS, ACS, CTC,
or interlocking limits
Breach - answerTo enter an area between two adjacent tracks
Cab Red Zone - answerExists during critical times or when multiple tasks are occurring;
an environment must be created in the locomotive control compartment that focuses
exclusively on controlling the train, verbally communicating restrictions, and proper
application of the rules
Cab Signal - answerA signal in the engineers compartment or can that indicated a
condition affecting train movement. Cab signals are used with interlocking or block
signals or without block signals.
Cars - answerRailroad cars
Centralized Taffic Control - answerA block system that uses block signal indications to
authorize train movements
Clearance Point - answerThe 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. Clearance Point location may be identified by a clearance cone and/or
painting of rails and ties
Conductor - answerCrew member in charge of train or yard crew
Control Operator - answerEmployee assigned to operate a CTC or interlocking control
machi8ne or authorized to grant track permits
Control Point - answerThe location of absolute signals controlled by a control operator
Controlled Siding - answerA siding within CTC or interlocking limits where a signal
indication authorizes the sidings use
Controlled Signal - answerAn absolute signal controlled by a control operator
Crew Member - answerConductors, assistants, brakemen, engineers, remote control
operators, yard engine foremen, switchmen, and yard helpers
Crossing at Grade - answerCrossings that intersect at the same level
Crossover - answerA combination of two switchers that connect two adjacent tracks,
normally used for crossover movements. Speed is restricted to the lowest connected
turnout speed
Definitions
Automatic Block Signal System - answer 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.
Absolute Block - answer A length of track that no train is permitted to enter while the
track is occupied by another train
Absolute Signal - answer A block or interlocking signal without a number plate or
designated by an A marker
Adjacent Track - answer Parallel tracks that are not separated by a single lane roadway
or similar distance; only applies if Track Breach Protection is required
Articulated - answer Permanently connected multiple unit cars that share a common
truck
Automatic Train Control Actuator - answer An ATC brake applying apparatus
Automatic Cab Signal System - answerA system that allows cab signals and the cab
warning whistle to operate automatically
Automatic Train Control - answerA system to enforce compliance with cabin signal
indications. If the train exceeds a predetermined speed for a given cab signal indication
and speed is not reduced at a sufficient rate, brakes are automatically applied.
Automatic Train Stop Systems - answerA system activated by wayside inductors
positioned to apply the brakes automatically until the train stops
Block - answerA length of track: between consecutive block signals, between a block
signal and the end of block system limits, or in automatic train control limits, the use of
which is governed by cab signals and/or block signals
Block Register Territory - answerA method of operation in non-signal territory where
trains, men, and equipment are authorized to occupy the main track in limits designated
by the timetable
Block Signal - answerA fixed signal at the entrance of a block that governs trains
entering and using that block
, Block System - answerA block or series of consecutive blocks within ABS, ACS, CTC,
or interlocking limits
Breach - answerTo enter an area between two adjacent tracks
Cab Red Zone - answerExists during critical times or when multiple tasks are occurring;
an environment must be created in the locomotive control compartment that focuses
exclusively on controlling the train, verbally communicating restrictions, and proper
application of the rules
Cab Signal - answerA signal in the engineers compartment or can that indicated a
condition affecting train movement. Cab signals are used with interlocking or block
signals or without block signals.
Cars - answerRailroad cars
Centralized Taffic Control - answerA block system that uses block signal indications to
authorize train movements
Clearance Point - answerThe 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. Clearance Point location may be identified by a clearance cone and/or
painting of rails and ties
Conductor - answerCrew member in charge of train or yard crew
Control Operator - answerEmployee assigned to operate a CTC or interlocking control
machi8ne or authorized to grant track permits
Control Point - answerThe location of absolute signals controlled by a control operator
Controlled Siding - answerA siding within CTC or interlocking limits where a signal
indication authorizes the sidings use
Controlled Signal - answerAn absolute signal controlled by a control operator
Crew Member - answerConductors, assistants, brakemen, engineers, remote control
operators, yard engine foremen, switchmen, and yard helpers
Crossing at Grade - answerCrossings that intersect at the same level
Crossover - answerA combination of two switchers that connect two adjacent tracks,
normally used for crossover movements. Speed is restricted to the lowest connected
turnout speed
