deutsches Glossar

An abridged form of this glossary with about 200 catchwords you find in the textbook Railway Operation and Control.

A

ABS
Abbr. to AUTOMATIC BLOCK SIGNALING

ABSOLUTE BLOCK
See: BLOCK SECTION

ABSOLUTE BLOCK SYSTEM
A fixed block system in which a train may enter a block section only after the last train ahead has completely cleared the block section and is protected by a stop signal.

ABSOLUTE PERMISSIVE BLOCK (APB)
An automatic block system on single lines on US railroads which is completely controlled by track circuits providing protection against opposing and following movements without opposite locking.

APB
Abbr. to ABSOLUTE PERMISSIVE BLOCK

ABSOLUTE SIGNAL
A signal that must not be passed in stop position without a special permission from the operator.

ANALYTIC CAPACITY RESEARCH
A method of capacity research that calculates data from the infrastructure and timetable characteristics to determine and describe the capacity without simulation.

APPROACH LOCKING
Form of route locking that comes into force after the train has occupied the approach section.

APPROACH SIGNAL
An interlocking signal in approach to a home signal that does not directly protect switches but that is interlocked to switches within the overlap of the home signal.

APPROACH TIME
The running time between a signal that provides an approach aspect and the following signal.

ASYNCHRONOUS SIMULATION
A method to simulate railroad operations by scheduling stochastically generated train paths. The different train classes are scheduled one after the other (i.g. asynchronous) in accordance to their priority. Train path conflicts are solved by scheduling rules. (see also: SYNCHRONOUS SIMULATION)

ARS
Abbr. to AUTOMATIC ROUTE SETTING

ATC
Abbr. to AUTOMATIC TRAIN CONTROL

ATO
Abbr. to AUTOMATIC TRAIN OPERATION

ATP
Abbr. to AUTOMATIC TRAIN PROTECTION

ATS
Abbr. to AUTOMATIC TRAIN STOP

AUTOMATIC BLOCK SIGNALING
A form of operation in which fixed block signals are controlled by an automatic block system.

AUTOMATIC BLOCK SYSTEM
A block system in which the signals work automatically. Lines with an automatic block system must be equipped with track clear detection.

AUTOMATIC ROUTE SETTING (ARS)
A system that provides the automatic setting of the proper route when a train approaches a signal. (see also: DESTINATION-BASED AUTOMATIC ROUTE SETTING, TIMETABLE-BASED AUTOMATIC ROUTE SETTING)

AUTOMATIC SIGNAL
A signal that is operated automatically.

AUTOMATIC SWITCH SETTING
An appliance that provides an automatic setting of switches when a route is lined up.

AUTOMATIC TRAIN CONTROL (ATC)
1) Another term for a continuous automatic train protection (ATP) system
2) An automatic train protection (ATP) system that is combined with a device for automatic train operation (ATO).

AUTOMATIC TRAIN OPERATION (ATO)
A system that guides the train automatically by the information provided by an ATP system.

AUTOMATIC TRAIN PROTECTION (ATP)
A system that transmits information about movement authorities and speed limits from the line to the train to cause automatic braking if the train ignores the valid limits.

AUTOMATIC TRAIN STOP (ATS)
1) A simple form of an intermittent ATP system that only provides an automatic train stop when passing a stop signal but no braking curve supervision in approach to a stop signal.
2) The part of an ATP system that automatically applies the train brakes when the engineer fails to acknowledge a restrictive signal.

AXLE COUNTER
A track clear detection system consisting of counting points at both ends of a section and a counter connected to the counting points. The occupancy of a section is detected by comparing the number of axles which enter the section with the number of axles which leave the section.

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BALISE
A transponder that is used as a data point in an intermittent automatic train protection (ATP) system or as reference point for train location in radio-based train control.

BERTH TRACK CIRCUIT
The track circuit that is immediately on the approach to a signal. That term is mainly used in British signaling.

BIDIRECTIONAL SIGNALING
A signaling system for two-way working.

BLOCK AND LOCK SYSTEM
Another term for interlocked manual block.

BLOCKING
Assorting freight cars within a train into groups (blocks) bound for individual destinatons.

BLOCK SECTION
A section of track in a fixed block system which a train may only enter when it is not occupied by other vehicles.

BLOCK SIGNAL
A signal that governs train movements into a block section.

BLOCK SYSTEM
A signaling system that provides a safe spacing of trains. Block systems may be divided into fixed block systems and moving block systems.

BLOCKING TIME
The time interval in which a section of track is exclusively allocated to a train and therefore blocked for other trains.

BLOCKING TIME STAIRWAY
A graph displaying the blocking times of all block sections a train passes into a time-over-distance diagram.

BLOCK MARKER
A fixed sign that marks the limit of a block section in a cab signal territory.

BRAKEMAN
A member of a train crew who assists the engineer in the train handling.

BRAKING PERCENTAGE
The percentage of the braking weight on the actual weight of a vehicle or train. The braking percentage may exceed 100 %. This value is mainly used for braking evaluation on UIC railroads. (see also: BRAKING RATIO)

BRAKING RATIO
The brake cylinder force divided by the weight of the vehicle. This value is mainly use for braking evaluation on North American railroads. (see also: BRAKING PERCENTAGE)

BRAKING WEIGHT
The weight, the brake of a vehicle can safely bring to a stop under specified conditions. The braking weight is determined by standardized braking tests and may exceed the actual weight of the vehicle. (see also: BRAKING PERCENTAGE, BRAKING RATIO)

BRANCHLINE, BRANCH
A line diverging from a main line to serve smaller towns with low traffic.

BUFFER STOP
British term for a bumper.

BUFFER TIME
An extra time that is added to the minimum line headway to avoid the transmission of small delays.

BUMPER
A device that prevents vehicles from overrunning the dead-end of a stub track.

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CABOOSE
A staffed car at the rear end of freight trains on US railroads. Today, a caboose is only required on lines with time spacing.

CAB SIGNALING
A signaling system that displays the movement authorities on the control panel in the locomotive cab.

CALL-ON SIGNAL
A subsidiary signal that allows a train cautiously to pass a stop signal.

CAPACITY
The maximum traffic flow a piece of infrastructure (line, interlocking, terminal, yard) can handle under specified operating conditions.

CAPACITY RESEARCH
The usage of methods of railroad operations research to determine the capacity of lines, interlockings, terminals and yards. (see also: ANALYTIC CAPACITY RESEARCH, SYNCHRONOUS SIMULATION, ASYNCHRONOUS SIMULATION)

CAR RETARDER
See: RETARDER

CASCADE LOCKING
A form of tabular interlocking in which a route is established by a locking sequence which is effected by permanent and conditional lockings between switches and signals. (see also: ROUTE-RELATED_LOCKING)

CENTRALIZED TRAFFIC CONTROL (CTC)
A control system in which the local interlockings are remote-controlled by a dispatcher and the trains are governed by signal indication.

CLASSIFICATION
Assembling freight cars into trains bound for specific destinations.

CLASSIFICATION BOWL
A subyard of a classification yard which contains the classification tracks.

CLASSIFICATION SIGNAL
Signals that are displayed by trains on lines with timetable and train order operation to mark extra trains and trains that are divided in sections.

CLASSIFICATION TRACK
A track in the classification bowl designated to a specific destination.

CLASSIFICATION YARD
A freight yard in which incoming cars are classified for new train destinations. (see also: GRAVITY YARD, FLAT YARD)

CLEARING POINT
A point a train must have cleared completely before a signal or an interlocked route may be unlocked.

CLOCK FACE TIMETABLE
A timetable in which trains that belong to the same route are scheduled with fixed time intervals between their train paths.

CLOSED BLOCK
A fixed block system in which the line is blocked in normal state and only cleared when a train is going to enter the block section.

CODED TRACK CIRCUIT
A track circuit in which the track current is overlaid by a code that contains signal information.

COLLATERAL DELAY
A delay that was transmitted from another train. (see also: INITIAL DELAY)

COLOR LIGHT SIGNAL
A light signal that displays the aspects by the color of lights.

COLOR POSITION LIGHT SIGNAL
A light signal which displays the aspects by the color and the position of lights.

COMMAND INTERLOCKING
An interlocking system in which a signal in a dependent interlocking station can only be cleared after it has been remotely unlocked from the command interlocking station.

COMMAND INTERLOCKING STATION
An interlocking station from which an interlocking signal in the district of a dependent interlocking station must be remotely unlocked to be cleared for a route.

COMMON SIGNAL
A signal that applies to any of a group of converging tracks.

CONDITIONAL CROSSLOCK
A crosslock that is only in effect as long as a route is set up or a signal is cleared. (see also: PERMANENT CROSSLOCK)

CONDITIONAL LOCKING
An interlocking between a switch and a signal in which the locking of the switch by clearing the signal depends on the position of other switches.

CONDUCTOR
The chief of a train crew.

CONFLICTING LOCKING
The interlocking between two conflicting routes that require one or more switches set in opposite positions. (see also: PLAIN CONFLICTING ROUTES, OPPOSING LOCKING)

CONFLICTING ROUTES
Interlocked routes that must not be set up at the same time. (see also: PLAIN CONFLICTING ROUTES, SPECIAL CONFLICTING ROUTES)

CONSECUTIVE DELAY
Another term for collateral delay.

CONSOLIDATED YARD
Australian term for an area where interlockings controlled by one signaling location have intervening automatic signals.

CONTINUOUS AUTOMATIC TRAIN PROTECTION
An ATP system in which the train receives data at all times in order to control the protection system.

CONTROL CENTER
A centralized control system that controls the train movements in a large territory.

CONTROLLED MANUAL BLOCK
A manual block system in which the signals are operated manually and controlled by continuous track circuits, requiring co-operation between the operators of adjacent block stations.

CONTROLLED POINT
A station where signals are remote-controlled from a control station.

CONTROLLED SIDING (CS)
A circuited siding in which train movements are governed by signals under control of a dispatcher or operator.

CONTROLLED SIGNAL
A signal that is locally or remotely controlled by an operator.

CONTROL LENGTH OF A SIGNAL
The length of track behind a signal that must be clear as long the signal displays a proceed aspect.

CONTROL STATION
The dispatcher's office or the location where an operator is on duty and from which remote-controlled signal appliances are operated.

CROSSING
An intersection of two tracks at grade.

CROSSLOCK
An appliance that provides a permanent interlocking of a switch with a derailer or with another switch.

CROSSOVER
An arrangement of corresponding turnouts providing a connection between two parallel tracks.

CTC
Abbr. to CENTRALIZED TRAFFIC CONTROL

CURRENT OF TRAFFIC
A direction specified by the rules for all train movements on a main track.

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DARK TERRITORY
A territory with a non-signaled operation.

DEPARTURE YARD
A subyard of a classification yard in which trains are prepared for departure.

DEPENDENT POINT LOCK
A point lock that is actuated by the same device as that which drives the points.

DEPENDENT INTERLOCKING STATION
An interlocking station in which a signal can only be cleared after it has been remotely unlocked from the command interlocking station.

DERAIL (am.), DERAILER (brit.)
A flank protection device that would derail an unsafe movement before it could join the protected route.

DESTINATION-BASED AUTOMATIC ROUTE SETTING
An automatic route setting system in which a route to the proper destination of a train is set up regardless of the scheduled train sequence in the timetable. (see also: TIMETABLE-BASED AUTOMATIC ROUTE SETTING)

DESTINATION SIGNAL
An interlocking signal at the exit of an interlocked route. It is also called the exit signal of that route. (see also: ENTRANCE SIGNAL)

DETONATOR
Another term for a torpedo. This term is mainly used outside of North America.

DIAMOND
The inner part of a crossing where the rails form a diamond shape.

DIRECTION LOCKING
A form of opposite locking in which a locked direction of travel is established on a block line that may consist of several block sections.

DIRECT TRAFFIC CONTROL (DTC)
A radio-based occupation control system for non-signaled lines in which the train crews receive exclusive authority to occupy one or more blocks.

DISPATCHER
An employee who supervises the train movements of a line or a certain area. In CTC territory the dispatcher also does the work of an operator.

DISTANT SIGNAL
A signal that provides an approach aspect to a following signal but that cannot show a stop aspect. A distant signal does not limit a block section.

DOUBLE SLIP CROSSING
Another term for a double slip switch.

DOUBLE SLIP SWITCH
A crossing combined with four pairs of points to provide slip connections at both sides of the crossing.

DRILL SIGNAL
North American term for a special signal indication for authorizing yard movements.

DTC
Abbr. to DIRECT TRAFFIC CONTROL

DUAL CONTROL SWITCH
A remote-controlled switch, that can also be hand-operated.

DUAL PROTECTIVE SWITCH
See: SELECTIVE PROTECTIVE SWITCH

DWARF SIGNAL
A ground mounted signal.

DWELL TIME
The total elapsed time from the time that a train stops in a station until the time it resumes moving.

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EDDY-CURRENT BRAKE
A brake system, in which the braking force is produced by the eddy-current iduced in the rails by an electro magnet moving above the rail without touching the rail surface. (see also: MAGNETIC RAIL BRAKE)

ELECTRIC INTERLOCKING
An interlocking system in which the interlocking is achieved by a mechanical lever frame with miniature levers and the switches and signals are operated by electric motors and are controlled electrically.

ELECTRONIC INTERLOCKING
See: MICROCOMPUTER INTERLOCKING

ELECTRO-PNEUMATIC INTERLOCKING
An interlocking system in which the interlocking is achieved by a mechanical lever frame and with miniature levers the switches and signals are operated by pneumatic cylinder drives and are controlled electrically.

EMERGENCY ROUTE RELEASE
A manually initiated release of a route or parts of a route if normal route release fails after the passage of a train. (see also: ROUTE CANCELLATION

EMPLOYEE'S TIMETABLE
A timetable for official use by railroad employees.

END OF TRAIN TELEMETRY (EOT), FLASHING REAR END DEVICE (FRED)
A device with an integrated rear end marker which is mounted at the rear car of a train and connected to the airbrake pipe to check train integrity by radio transmission to the leading engine.

ENGINEER
An employee who drives an engine.

ENTRANCE-EXIT OPERATION
A form of operating an interlocking machine by pushing a bottom at the entrance and the exit of a route.

ENTRANCE SIGNAL
An interlocking signal at the entrance of an interlocked route. (see also: EXIT SIGNAL)

EOT
Abbr. to END OF TRAIN TELEMETRY

EXIT SIGNAL
1) A interlocking signal that governs train movements to leave a station track. It is also called a station exit signal. (mainly used outside North America).
2) North American term for an opposing interlocking signal a train passes when leaving interlocking limits.
3) An interlocking signal at the exit of an interlocked route. (see also: ENTRANCE SIGNAL)

EXPLOITATION RATE
The sum of headway in a considered period of time divided by the total duration of this period.

EXTRA TRAIN
A train that does not run on a scheduled train path.

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FACING POINT MOVEMENT
A movement on a turnout in which the points face approaching traffic.

FIXED BLOCK SYSTEM
A block system in which the track behind a train is sectionally cleared in form of fixed block sections.

FIXED INTERVAL TIMETABLE
Another term for a clock face timetable.

FLAGMAN
A member of the train crew who provides flag protection.

FLAG PROTECTION
A method to protect a train by a member of the train crew who gives stop signals (fusees, flag signals, torpedos) to following and (if required) opposing trains.

FLANK LOCKING
The locking of protective switches in the flank protecting position

FLANK PROTECTION
A method to prevent vehicles from running into a route which is cleared for an approaching train.

FLANK PROTECTION AREA
The section of track between a flank protection device and the fouling point of the route to be protected.

FLASHING REAR END DEVICE (FRED)
See: END OF TRAIN TELEMETRY

FLAT SWITCHING
A switching method in which cars are moved by an engine. (see also: GRAVITY SWITCHING)

FLAT YARD
A classification yard in which classification is done by flat switching. (see also: HUMP YARD)

FLEETED SIGNAL
An interlocking signal on which fleeting is in effect.

FLEETING
1) An automatic mode of an interlocking signal in which the route remains in a locked state and the signal works like an automatic block signal
2) A scheduling principle in which trains of equal speed or direction are assembled into fleets.

FORMATION YARD
Another term for a classification yard (mainly used outside of North America).

FOULING POINT
The limit of occupation of converging tracks at turnouts and crossings.

FOULING POINT INDICATOR
A ground mounted sign to mark the fouling point.

FRED
Abbr. to FLASHING REAR END DEVICE

FROG
The part of a turnout, a crossing, or a gantlet, where the rails have an intersection which allows the wheel flanges to cross the running rail.

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GANTLET
A track arrangement found on double-track lines that uses a frog to cross the inner rail of one track over the inner rail of another.

GEOGRAPHICAL INTERLOCKING
An interlocking system in which the track elements are represented by logical objects connected to each other in form of the track layout.

GRAVITY SWITCHING
A switching method in which the cars run down a gradient driven by gravity into their classification tracks. (see also: FLAT SWITCHING, HUMP YARD, GRAVITY YARD)

GRAVTY YARD
A classification yard that is set up on a continuous falling gradient. Compared with a hump yard, a gravity yard requires less use of switching engines. (see also: FLAT YARD, GRIDIRON YARD)

GRIDIRON YARD
An type of a gravity yard in which several successive ladders form a gridiron shaped track layout.

GROUND FRAME
A ground mounted small lever frame to enable a group of switches to be locally controlled by train or yard crews.

GROUP RETARDER
A retarder that serves a group of classification tracks. (see also: MASTER RETARDER)

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HEADWAY
The time interval between two successive trains.

HOME SIGNAL
A signal governing entrance to an interlocking.

HOME SIGNAL LIMITS
A track layout that is protected by opposing home signals. On North American railroads the home signal limits always equal the interlocking limits. On some railroads outside of North America home signal limits may contain more than one interlocking.

HUMP
An artifical hill in a hump yard where cars are pushed over to let gravity drive them into the classification tracks.

HUMP YARD
A classification yard in which the cars run down a hump into the classification bowl. (see also: FLAT YARD, GRAVITY YARD)

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IMPEDANCE_BONDS
An electrical appliance that enables the return current of electric traction to pass insulated rail joints.

INDEPENDENT POINT LOCK
A point lock that is actuated by a separate device from that which drives the points.

INITIAL DELAY
A delay that was not transmitted from another train. (see also: COLLATERAL DELAY)

INSULATED RAIL JOINT
A rail joint that ensures electrical insulation of adjacent rails to limit a track circuit.

INTERLOCKED MANUAL BLOCK
A manual block system in which the block instruments are interlocked with the signals.

INTERLOCKING
An arrangement of switches and signals interconnected in a way that each movement follows the other in a proper and safe sequence.

INTERLOCKING LIMITS
The tracks between the outer opposing absolute signals of an interlocking.

INTERLOCKING PLANT
The trackage within the limits of an interlocking.

INTERLOCKING SIGNAL
A signal that governs a locked route or within an interlocking.

INTERLOCKING STATION
A location from which an interlocking is operated.

INTERLOCKING TABLE
Another term for a locking table.

INTERLOCKING TOWER
North American term for an interlocking station.

INTERMEDIATE BLOCK SIGNAL
A block signal that is located between different interlockings.

INTERMEDIATE INTERLOCKING SIGNAL
An interlocking signal that is neither a home signal nor it governs a route to leave the home signal limits.

INTERMEDIATE SWITCH
A switch that is located between two interlocking signals in a way that a train that is waiting at the signal ahead would not clear the switch. Intermediate switches must be interlocked both with the signal in rear and with the signal in advance.

INTERMITTENT ATP
An ATP system in which the data is transmitted to the train at discrete points along the track.

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JOINTLESS TRACK CIRCUIT
A track circuit that uses an AC audio frequency current, so that the working length is limited by the capacitive and inductive track characteristics without a need for insulated rail joints.

JUNCTION
An arrangement of tracks and turnouts in which a line is joined by another one.

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LADDER
A group of parallel tracks connected by a ladder track.

LADDER TRACK
A track that provides access to a series of parallel tracks.

LEAVING SIGNAL
North American term for a signal that governs train movements to leave a siding, yard, or branchline.

LEVERMAN
An employee who operates an interlocking machine (lever frame) under supervision of a train director.

LEVER SEQUENCE
The sequence in which the levers have to be operated to line up a route on an interlocking machine with cascade locking.

LIGHT SIGNAL
A signal in which the aspects are given by the color and/or position of lights.

LINE HEADWAY
The headway that results from the blocking time stairways of two successive trains.

LINE RESISTANCE
The runnings resistance produced by the grade and the curvature of the line. (see also: TRAIN RESISTANCE)

LOCKING FRAME
A mechanical locking system that effects the interlocking between the levers of a mechanical, electric or electro-pneumatic interlocking machine.

LOCKING SHEET
Another term for a locking table.

LOCKING TABLE
A tabular sheet that contains all interlocking dependencies of an interlocking.

LOOP
Another term for a passing siding. This term is mainly used outside of North America.

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MAGNETIC RAIL BRAKE
A brake system, in which the braking force is produced by an electro magnet pressed on the rail surface. (see also: EDDY-CURRENT BRAKE)

MAIN ROUTE
British term for a train route.

MAIN SIGNAL
A signal that governs train movements. This term is used by railroads outside of North America to distinguish these signals from shunting signals.

MAINTAINED LOCKING
Another term for route holding.

MAIN TRACKS
The tracks that may be used for regular train movements.

MANUAL BLOCK
A fixed block system in which the signals are operated manually and the clearing of the block sections is checked by local operators watching the rear end markers.

MANUAL SIGNAL
A signal that is operated manually.

MARSHALLING YARD
British term for a classification yard.

MASTER RETARDER
The first retarder cars pass while running down a hump. (see also: GROUP RETARDER)

MECHANICAL INTERLOCKING
An interlocking system in which the interlocking is achieved by a mechanical lever frame and the switches and signals are operated by muscle power with rod or wire transmission.

MICROCOMPUTER INTERLOCKING
An interlocking system in which the interlocking is achieved by software.

MINIMUM RUNNING TIME
The shortest running time as a result from a running time calculation.

MOVABLE FROG
A pivoting or flexible frog that is operated by a switch machine to close the rail gap at the frog in accordance to the route that is set up.

MOVING BLOCK SYSTEM
A block system in which the track behind a train is cleared continously.

MULTIPLE-BLOCK SIGNALING
A signaling system in which the main signals provide information about the clearance of more than one block section.

MULTI-UNIT LIGHT SIGNAL
A color light signal with independent light units and every unit using one light.

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NON SIGNAL-CONTROLLED OPERATION
An operating procedure in which the traffic is controlled by verbal or written authority. A non signal-controlled operation may be combined with a signaling system as a safetey overlay. (see also: SIGNAL-CONTROLLED OPERATION)

NON-SIGNALED OPERATION
A form of a non signal-controlled operation in which the traffic is controlled by verbal or written authority and the train separation is not protected by a signaling system.

NORMAL RUNNING TIME
The scheduled running time as the sum of the minimum running time and the recovery time.

NX OPERATION
Abbr. to ENTRANCE-EXIT OPERATION

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ONE-BLOCK SIGNALING
A signaling system in which the main signals provide information about the clearance of only one block section.

OPEN BLOCK
A fixed block system in which the line is cleared in normal state and only blocked as long as a train has occupied the block section.

OPEN LINE
Main tracks outside of station areas (not used in North American and British signalling).

OPERATING PROCEDURE
A system of operating rules and technical appliances to operate trains on a railroad infrastructure.

OPERATOR
An employee who controls train movements.

OPPOSING LOCKING
The interlocking between opposing routes leading into the same track section.

OPPOSITE LOCKING
The part of an interlocked block system to prevent opposing movements in single line operations. (see also: DIRECTION LOCKING)

ORIGINAL DELAY
Another term for initial delay.

OVERLAP
A certain length of track behind a signal that must not be occupied as long a train movement is approaching this signal.

OVERLAPPING OVERLAPS
Another term for shared overlaps.

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PERIODIC TIMETABLE
Another term for a clock face timetable.

PERMANENT CROSSLOCK
A crosslock that is permanently in effect. (see also: CONDITIONAL CROSSLOCK)

PERMISSIVE SIGNAL
A signal that may be cautiously passed in stop position after the train has stopped at the signal. After passing a permissive signal in stop position the movement in the next block section must be made at restricted speed.

PLAIN CONFLICTING ROUTES
Conflicting routes that require switches set in opposite positions. (see also: SPECIAL CONFLICTING ROUTES)

POINT INDICATOR
Another term for a switch indicator. This term is mainly used outside of North America.

POINT LOCK
A locking device that mechanically locks the points of a switch in a proper position to prevent unattended movements of the points and movable frogs as long a train is running through the switch.

POINT MACHINE
Another term for a switch machine. This term is mainly used outside of North America.

POINTS
The movable parts of a turnout that are operated to set up different routes.

POSITION LIGHT SIGNAL
A light signal that indications are given by the position of two or more lights.

POSITIVE TRAIN CONTROL (PTS)
An advanced Automatic Train Protection system that enforces movement authorities, all speed restrictions (signal and civil), and protection of roadway workers. This term is mainly used for radio-based systems in North America.

POSITIVE TRAIN SEPARATION (PTS)
An Automatic Train Protection system that prevents trains from overrunning movement authority limits. This term is mainly used for radion-based systems in North America.

PRIMARY DELAY
Another term for initial delay.

PROTECTION SIGNAL
A signal that displays a stop aspect for protection purposes but that is not used to authorize regular train movements.

PROTECTION TRANSPORTATION SWITCH
A switch that is located between an element that provides remote flank protection and the route to be protected.

PROTECTIVE SWITCH
A switch that is locked in a protective position to provide flank protection to a route.

PTC
Abbr. to POSITIVE TRAIN CONTROL

PTS
Abbr. to POSITIVE TRAIN SEPARATION

PURE RUNNING TIME
The shortest possible running time between scheduled stops as a result from a running time calculation.

PUZZLE SWITCH
Another term for a double slip switch.

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RADIO-BASED TRAIN CONTROL
A form of operation in which the movement authorities are issued by a radio block center.

RADIO BLOCK CENTER
A control center to supervise and control train movements in a territory with radio-based train control.

RADIO ELECTRONIC TOKEN BLOCK (RETB)
A form of radio-based train control in which the movement authority for a block section is issued in form of an electronic token which is transmitted by radio from the radio block center to the train. After the train has cleared the section the token is send back to the radio block center.

REAR END MARKER
A marker at the rear end of a train.

RECEIVING YARD
A subyard of classification yard in which the incoming trains arrive.

RECOVERABILITY OF THE TIMETABLE
The ability of a timetable to reduce the consequences of delays.

RECOVERY TIME
A time supplement that is added to the pure running time to enable a train to make up small delays.

RELAY INTERLOCKING
An interlocking system in which the interlocking is achieved by relay circuits.

REMOTE FLANK PROTECTION
A flank protection that is provided by an element that is not directly neighbored to the route to be protected.

RESTRICTED SPEED
A speed that allows to stop short of a vehicle or obstruction.

RETARDER
A trackside braking device used in gravity switching to control cars running down a hump.

RIGID CROSSING
A crossing without movable frogs.

ROTATION LOCKING
An interlocking appliance that prevents a second operation of a control unit after certain conditions have been met.

ROUTE
A path through an interlocking, along which an authorized movement is to be made.

ROUTE CANCELLATION
A manually initiated release of a locked route after having restored the signal. (see also: EMERGENCY ROUTE RELEASE)

ROUTE CLEARING POINT
A point that a train must have cleared completely before a locked route or sections of a locked route may be released.

ROUTE CONFLICT RATE
The number of conflicting route combinations divided by the total number of route combinations of an interlocking.

ROUTE HOLDING
A locking function that maintains all locking conditions of a route until the train has passed clear the clearing point of the relevant route elements.

ROUTE LOCKING
The locking of all switches as long a route is established.

ROUTE MONITORING
A continuous procedure that checks all signaling conditions of a route and transfers the information towards the entrance signal.

ROUTE PRESELECTION
The selection of a route while a conflicting route has still not released. After the conflicting route has released the preselected route will be setted automatically.

ROUTE-RELATED LOCKING
A form of tabular interlocking in which all elements of a route are locked at once by a route locking element that releases the signal to be cleared. The switches and signals are not directly connected by locking sequences. (see also: CASCADE LOCKING)

ROUTE RELEASE
The release of locked switches after the train has cleared the clearing point of a route.

ROUTE SIGNALING
A signaling system in which the facing point signals indicate the route respectively the direction in which the train is being sent.

RUNNING LINE
British term for a main track.

RUNNING MOVEMENT
British term for a train movement.

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SAFETY SWITCH
Another term for a protective switch.

SCHEDULE
The designation of train description, day, route, speed, arrival and departure times of a train.

SCHEDULED WAITING TIME
The waiting time that is needed for a scheduled passing and overtaking and to synchronize the schedules of a fixed interval timetable.

SEARCHLIGHT SIGNAL
A color light signal with light units in which the aspect is given by a mechanism placing one of a number of roundels of the color required, situated near the focus of the lens unit, in front of the lamp.

SECONDARY DELAY
Another term for collateral delay.

SECONDARY TRACKS
North American term for tracks that are not usually used for regular train movements.

SECTION SIGNAL
British term for a signal that governs train movements to leave station limits.

SELECTIVE OVERLAP
A form of overlap protection, in which the operator, when setting up a route, can select one of several possible overlaps. In difference to swinging overlaps, once the signal has been cleared, the overlap cannot be changed without cancelling the route.

SELECTIVE PROTECTIVE SWITCH, DUAL PROTECTIVE SWITCH
A protective switch that may be required for flank protection by two route elements both in normal and reverse position at the same time. See also: SUBSEQUENT FLANK PROTECTION

SELF-SELECTIVE PROTECTIVE SWITCH
A protective switch that would be required for flank protection by two route elements of the same route both in normal and reverse position at the same time. There must determined a position for the switch to be locked in.

SEMAPHORE SIGNAL
A signal that gives the indication by the position of movable arms or disks.

SEMI-AUTOMATIC SIGNAL
A controlled signal that my be switched into an automatic mode.

SHARED OVERLAPS
Two or more overlaps simultanously leading into the same track section without producing a route conflict.

SHUNTING
Another term for switching that is used on railroads outside of North America.

SHUNTING LIMITS
A territory limited by shunting limit boards or other points designated in the operating instructions, where shunting units may enter main tracks in charge of a local operator without authority from the train director. Yard limits instead of shunting limits are used in North America..

SHUNTING LIMIT BOARD
A fixed sign that must not be passed by shunting movements. It is used by railroads outside of North America where yard limits are unknown.

SHUNTING SIGNAL, SHUNT SIGNAL
A fixed signal that is used to authorize shunting movements. This term is used by railroads outside of North America to distinguish these signals from main signals.

SHUNTING UNIT
An engine with or without cars that is authorized to run as a shunting movement. This term is used by railroads outside of North America where yard limits are unknown.

SHUNT ROUTE
A locked route used for shunting movements. This term is used by railroads outside of North America which distinguish shunt routes from train routes.

SIDING
1) North American term for a track that is used for passing and overtaking trains.
2) Outside of North America, a track that may not be used for regular train movements.

SIGNAL ASPECT
The appearance of a lineside signal, as viewed from the direction of an approaching train, or the appearance of a cab signal.

SIGNAL BOX
British term for an interlocking station.

SIGNAL CABIN
Another term for an interlocking station.

SIGNAL CLEARING POINT
The point at the end of the overlap a train must have cleared completely to allow the signal at the entrance of the block section to be cleared again.

SIGNAL-CONTROLLED OPERATION
A form of operation in which train movements are governed by signal indication.

SIGNALED DTC
A form of DTC in which the line is equipped with a simplified signaling system as a safety overlay.

SIGNALED OPERATION
A form of operation in which train movements are governed by signal indication.

SIGNALED TWC
A form of TWC in which the line is equipped with a simplified signaling system as a safety overlay.

SIGNAL HEADWAY
The headway that results from the blocking times of two successive trains in one single block section.

SIGNAL INDICATION
The information that is given by a signal aspect.

SIGNALLER
British term for an employee who is in charge of operating signaling appliances.

SIMULATION
A method of capacity research in which, different from analytic capacity research, the running operational processes are modelled (mostly in a computer model). See also: ASYNCHRONOUS_SIMULATION, SYNCHRONOUS_SIMULATION.

SINGLE SLIP CROSSING
Another term for a single slip switch.

SINGLE SLIP SWITCH
A crossing combined with two pairs of points to provide a slip connection at one side of the crossing.

SLIP CROSSING
Another term for a slip switch.

SLIP SWITCH
A crossing that is combined with movable points for slip connections.

SPECIAL CONFLICTING ROUTES
Conflicting routes that do not differ in the position of switches. (see also: PLAIN CONFLICTING ROUTES)

SPEED SIGNALING
A signaling system in which the signals indicate the speed not to be exceeded by a train.

SPRING SWITCH
A switch that may be passed by trailing point movements in wrong position and returns to normal position under spring load after the passage.

SPUR TRACK, SPUR
A short stretch of track diverging from a main or branchline to serve a customer located away from the primary trackage.

STARTER SIGNAL
Old British term for a signal that governs train movements to leave station limits. It is now called a section signal.

STATION
1) A place designated in the timetable by name.
2) A place with a platform stop for passenger trains.
3) A short term for a station area (not used in North American and British signaling).

STATION AREA
A system of station tracks limited by opposing home signals (not used in North American and British signalling).

STATION EXIT SIGNAL
A interlocking signal that governs train movements to leave a station track (mainly used outside North America).

STATION LIMITS
British term for the line from the home signal and the last section signal (starter signal) of the same direction which is controlled from the same signal box. This does not apply on a track circuit block line.

STATION TRACK
A main track between successive interlocking signals within the same home signal limits (mainly used outside of North America).

STATION TRAFFIC DIAGRAM
A diagram that displays the scheduled occupation of the tracks in large stations and interlockings.

STUB TRACK
A dead-end track, usually equipped with a bumper.

SUBSEQUENT FLANK PROTECTION
A selective protective switch that, after the protected route element has released, will subsequently move to the protective position for another route element.

SUPERIOR TRAIN
A train having precedence over another train.

SWINGING OVERLAP
A form of overlap protection using a conditional crosslock that allows switching the overlap into another track without cancelling the route.

SWITCH
North American term for a pair of points. In North American railroad operation and signaling turnouts are usually referred to as switches.

SWITCH DIAMOND
A diamond crossing with movable frogs.

SWITCH INDICATOR
A sign that indicates the position of a switch.

SWITCHING
North American term for all movements other than train movements.

SWITCH MACHINE
A machine that is used to operate points, movable frogs or derails.

SYNCHRONOUS SIMULATION
A method to simulate railroad operations by modeling all partial processes of the operation in real time sequences. (see also: ASYNCHRONOUS SIMULATION)

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TABULAR INTERLOCKING
An interlocking system in which the locking between signals and switches is achieved in form of a locking table that contains all locking conditions for all train routes. Tabular interlocking can be effected by cascade locking or by route-related locking.

TCO
Abbr. to TRAIN CONTROL OFFICER

TELEGRAPH ORDER SYSTEM
A South African train message system in which local operators exchange train messages over a section with intermediate unsignaled and unstaffed passing sidings. At the entrance of the section a train gets an order that determines the meeting points with opposing trains within this section.

TRAIN RESISTANCE
The runnings resistance produced by the running characteristics of the train. (see also: LINE RESISTANCE)

TELEPHONE BLOCK
A manual block system in which the occupation of the block sections is controlled by telephone communication between the block operators.

TERMINAL
An assemblage of facilities provided at a terminus or at intermediate points of a line for the purpose of assembling, assorting, classifying and relaying trains.

TIME BLOCK SYSTEM
See: TIME SPACING

TIME LOCKING
An application that will hold a route locked for a specified time after the signal has been manually restored..

TIME SPACING, TIME BLOCK SYSTEM
A method of train separation in which a train must not follow another train until a specified time interval (usually 10 minutes) after the preceeding train has departed. In case of a delay, flag protection is required.

TIMETABLE
A document that contains the schedules of all trains of a line.

TIMETABLE AND TRAIN ORDER OPERATION
A form of non-signaled operation on US railways in which trains are governed by the timetable. In dark territory, trains are separated by time spacing combined with flag protection. The traffic is regulated by priority rules and train orders which are issued by the dispatcher.

TIMETABLE-BASED AUTOMATIC ROUTE SETTING
An automatic route setting system in which all routes are set up both in compliance with the proper destination of the trains and with the scheduled train sequence of the timetable. (see also: DESTINATION-BASED AUTOMATIC ROUTE SETTING)

TIMETABLE CAPACITY
The maximum number of train paths that could be scheduled on a line without considering buffer times.

TOKEN BLOCK SYSTEM
A block system for single track lines in which the movement authority for a block section depends on the posession of a token which is handed out the train engineer and handed back after clearing the section.

TOKENLESS BLOCK SYSTEM
A block system that works without exchanging a token between the control apparatus and the train engineer.

TORPEDO
An explosive signaling device, placed on the railhead and detonated by a passing vehicle.

TOWER
See: INTERLOCKING TOWER

TRACK CLEAR DETECTION
A device that detects the occupation and clearance of a track section.

TRACK CIRCUIT
A track clear detection device consisting of an electrical circuit of which the rails of a section form a part. The clearance of the section is detected by a detection device at one end of the section which receives a current from a source at the other end of the section.

TRACK CIRCUIT BLOCK
British term for a method of working trains on a track where safety is ensured by continuous track clear detection devices (track circuits, axle counters) without the requirement to visually confirm that trains are complete.

TRACK WARRANT
A written form for authorization of train movements in TWC territory.

TRACK WARRANT CONTROL (TWC)
A radio-based occupation control system for non-signaled lines in which trains may occupy main tracks only on the basis of the possession of a track warrant covering a precisely defined track segment of any length.

TRAFFIC CONTROLLER
Another term for a dispatcher. This term is used on some railroads outside of North America.

TRAFFIC DENSITY
The number of trains that are running at the same time on a certain portion of a line.

TRAFFIC DIAGRAM
A diagram that contains the train paths of all trains that run on a line.

TRAFFIC ENERGY
The traffic flow multiplied by the average transportation speed.

TRAFFIC FLOW
The number of trains per unit of time.

TRAILING POINT MOVEMENT
A movement on a turnout where the frog faces approaching traffic.

TRAIN, TRAIN MOVEMENT
An engine with or without cars displaying a rear end marker with with the authority to operate on main tracks in accordance to rules specified for train movements.

TRAIN CONTROL
The method of authorizing train movements.

TRAIN CONTROL OFFICER
South African term for an operator who is in charge of authorizing train movements.

TRAIN DESCRIBER
A system that identifies trains which occupy a block section on the display at the panel of the operator or dispatcher.

TRAIN DESCRIPTION
A number or an alphanumeric code for identification of a train and its schedule.

TRAIN DIRECTOR, TRAIN MOVEMENT DIRECTOR
An operator who has full responsibility to issue movement authorities to trains. A train director may supervise a number of levermen.

TRAIN MESSAGES
Messages exchanged between the operators of locally controlled stations for train movement control.

TRAIN MESSAGE SYSTEM
An European form of train control in which local operators exchange train messages.

TRAIN ORDER
An order form that is used for traffic regulation on lines operated by timetable and train order.

TRAIN ORDER SIGNAL
A signal that indicates that an approaching train has to pick up train orders.

TRAIN ORDER STATION
A station where train orders may be picked up by trains.

TRAIN PATH
A time-distance graph that represents the schedule of a train in a traffic diagram.

TRAIN REGISTER BOOK
British term for a train record.

TRAIN RECORD
A written sheet in which an operator records all train movements and train messages.

TRAIN ROUTE
A locked route for the safe passage of a train through an interlocking. (see also: MAIN ROUTE, SHUNT ROUTE)

TRAINSHEET
A document in which the dispatcher records all train movements and movement authorities.

TRIP STOP
Most simple form of an automatic train stop system (ATS) that is operated by mechanical contact between a trackside trip arm and a brake trip switch on the train.

TURNOUT
An assembly of rails, movable points and a frog, which effects the tangential branching of tracks and allows trains or vehicles to run over one track or another.

TWC
Abbr. to TRACK WARRANT CONTROL

TWO-WAY WORKING
An operating mode for double track lines where the tracks may be operated in both directions under block signal control.

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UNSIGNALED OPERATION
Another term for a non-signaled operation.

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WAITING TIME DIAGRAM
A diagram displaying the waiting time as a function of the traffic flow.

WARNER ROUTE
British term for a train route with a reduced overlap, since a full overlap is not available or not required.

WYE
A triangle track arrangement consisting of three turnouts or of two turnouts and a high angle crossing.

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YARD
1) An arrangement of tracks, other than main tracks, used for making up trains, storing cars and trains and other purposes
2) Australian term for the track system of a station area. (see also: CONSOLIDATED YARD)

YARD ENGINE
An engine in yard service that may occupy main tracks only within yard limits.

YARD LIMITS
1) North American term for a territory where yard engines may enter main tracks under simplified conditions without authority from the dispatcher
2) Australian term for the limits of a station area (see Autralian use of the term yard) that separates this area from the sections of the open line.

YARD MOVEMENT
A movement in a yard or within yard limits for switching purposes.