Glossary of Railway Operation and Control
last update: 2018-06-26
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Abbr. to AUTOMATIC BLOCK SIGNALLING
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 North American railways, which is completely controlled by track circuits providing protection against opposing and following movements without opposite locking.
Abbr. to ABSOLUTE PERMISSIVE BLOCK
1) A signal that must not be passed in stop position without permission from the operator.
2) An interlocking signal with a stop aspect that applies both to train movements and to shunting movements.
ANALYTICAL CAPACITY RESEARCH
A method of capacity research that calculates data from the infrastructure and timetable characteristics to determine and describe the capacity without simulation.
A signal that is cleared automatically on the approach of a train.
Form of route locking that comes into force after the train has occupied the approach section.
Another term for an outer home signal, which is mainly used in North American transit railway system.
The running time between a signal that provides an approach aspect and the following signal.
A method to simulate railroad operations by stochastically generated train paths. The different train classes are generated one after the other (i.g. asynchronous) in accordance to their priority. Train path conflicts are solved by scheduling rules. (see also: SYNCHRONOUS SIMULATION)
Abbr. to AUTOMATIC ROUTE SETTING
Abbr. to AUTOMATIC TRAIN CONTROL
Abbr. to AUTOMATIC TRAIN OPERATION
Abbr. to AUTOMATIC TRAIN PROTECTION
Abbr. to AUTOMATIC TRAIN STOP
AUTOMATIC BLOCK SIGNALLING
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 POINT SETTING
An appliance that provides an automatic setting of switches when a route is lined up.
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)
A signal that is controlled automatically by the trains moving along the line.
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. (see also: INTERMITTENT ATP, CONTINUOUS ATP)
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.
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.
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.
The track section, on which a train comes to a halt at a stop signal. That term is mainly used in British signalling.
BERTH TRACK CIRCUIT
The track circuit that is immediately on the approach to a signal. That term is mainly used in British signalling.
A signalling system for two-way working.
BLOCK AND LOCK SYSTEM
Another term for interlocked manual block.
Assorting freight cars within a train into groups (blocks) bound for individual destinatons.
A section of track in a fixed block system, which a train may only enter when it is not occupied by other vehicles.
A signal that governs train movements into a block section.
A signalling system that provides a safe spacing of trains. Block systems may be divided into fixed block systems and moving block systems.
The time interval in which a section of track is exclusively allocated to a train movement 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.
A fixed sign that marks the limit of a block section in a cab signal territory.
A member of a train crew who assists the engineer in the train handling.
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 railways. (see also: BRAKING RATIO)
The brake cylinder force divided by the weight of the vehicle. This value is mainly use for braking evaluation on North American railways. (see also: BRAKING PERCENTAGE)
The weight, the brake of a vehicle can safely bring to a stop under specified conditions. The braking weight is determined by standardised braking tests and may exceed the actual weight of the vehicle. (see also: BRAKING PERCENTAGE, BRAKING RATIO)
A line diverging from a main line to serve smaller towns with low traffic.
Kind of a bumper as used by railways on which the vehicles are equipped with buffers.
An extra time that is added to the minimum line headway to avoid the transmission of small delays.
A device that prevents vehicles from overrunning the dead-end of a stub track.
A staffed car at the rear end of freight trains on US railways. Today, a caboose is only required on lines with time spacing.
A signalling system that displays the movement authorities on the control panel in the locomotive cab.
A subsidiary signal that allows a train cautiously to pass a stop signal.
The maximum traffic flow a piece of infrastructure (line, interlocking, terminal, yard) can handle under specified operating conditions.
The usage of methods of railroad operations research to determine the capacity of lines, interlockings, terminals and yards. (see also: ANALYTICAL CAPACITY RESEARCH, SYNCHRONOUS SIMULATION, ASYNCHRONOUS SIMULATION)
A form of tabular interlocking in which a route is established by a locking sequence which is effected by permanent and conditional lockings between points and signals. (see also: ROUTE-RELATED_LOCKING)
CENTRALISED 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.
Assembling freight cars into trains bound for specific destinations.
A subyard of a classification yard which contains the classification tracks.
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.
A track in the classification bowl designated to a specific destination.
A freight yard in which incoming cars are classified for new train destinations. (see also: GRAVITY YARD, FLAT YARD)
A point a train must have cleared completely before a signal or an interlocked route may be released.
CLOCK FACE TIMETABLE
Another term for a cyclic timetable
1) 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.
2) An automatic block system, in which the automatic block signals show a stop aspect as the normal indication.
CODED TRACK CIRCUIT
A track circuit in which the track current is overlaid by a code that contains signal information.
A delay that was transmitted from another train. (see also: INITIAL DELAY)
COLOUR LIGHT SIGNAL
A light signal that displays the aspects by the colour of lights.
COLOUR POSITION LIGHT SIGNAL
A light signal which displays the aspects by the colour and the position of lights.
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.
A signal that applies to any of a group of converging tracks.
A method to estimate the consumed capacity by pushing the blocking time stairways of a given timetable together until there are no buffer times left.
A crosslock that is only in effect as long as a route is set up or a signal is cleared. (see also: PERMANENT CROSSLOCK)
An interlocking between points and a signal in which the locking of the points by clearing the signal depends on the position of other points.
The head of a train crew.
The interlocking between two conflicting routes that require one or more POINTS set in opposite positions. (see also: PLAIN CONFLICTING ROUTES, OPPOSING LOCKING)
Interlocked routes that must not be set up at the same time. (see also: PLAIN CONFLICTING ROUTES, SPECIAL CONFLICTING ROUTES)
Another term for collateral delay.
Australian term for an area where interlockings controlled by one signalling location have intervening automatic signals.
The total time comsumed by headways within a considered period.
An ATP system in which the train receives data at all times in order to control the protection system.
A centralised control system that controls the train movements in a large territory.
A humping control procedure, in which the cuts are retarded semicontinuously by densily spaced small retarders. (see also: FREE CUT)
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.
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.
A signal that is locally or remotely controlled by an operator.
CONTROL LENGTH OF A SIGNAL
The length of track beyond a signal that must be safe and clear as long the signal displays a proceed aspect.
The dispatcher's office or the location where an operator is on duty and from which remote-controlled signal appliances are operated.
An intersection of two tracks at grade.
An appliance that provides a permanent interlocking of points with a derailer or with other points.
An arrangement of corresponding turnouts providing a connection between two parallel tracks.
Cars that arrive in the wrong system of a double-sided classification yard, so that these cars have to go over both humps to reach their destination train.
Abbr. to CENTRALISED TRAFFIC CONTROL
CURRENT OF TRAFFIC
A direction specified by the rules for all train movements on a main track.
A single car or a group of coupled cars that run down a hump.
A timetable in which trains that belong to the same route are scheduled with fixed time intervals between their train paths.
A territory with a non-signalled operation.
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.
DERAILER(brit.), DERAIL (am.)
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)
An interlocking signal at the exit of an interlocked route. It is also called the exit signal of that route. (see also: ENTRANCE SIGNAL)
Another term for a torpedo. This term is mainly used outside of North America.
The inner part of a crossing where the rails form a diamond shape.
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-signalled lines in which the train crews receive exclusive authority to occupy one or more block sections.
An employee who supervises the train movements of a line or a certain area. A dispatcher may also perform the duty of a TRAIN CONTROL OPERATOR. (see also: TRAIN DISPATCHER)
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.
A track layout that combines a crossing with four pairs of points to provide slip connections at both sides of the crossing.
DOUBLE SLIP SWITCH
North American Term for a double slip.
North American term for a special signal indication for authorizing yard movements.
Abbr. to DIRECT TRAFFIC CONTROL
DUAL CONTROL POINTS
Remote-controlled points, that can also be hand-operated.
DUAL PROTECTIVE POINTS
See: SELECTIVE PROTECTIVE POINTS
A ground mounted signal.
The total elapsed time from the time that a train stops in a station until the time it resumes moving.
EARLY TARGET SHOOTING
A humping control procedure, in which the braking target is the begin of the classification track. (see also: TARGET SHOOTING)
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)
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.
See: MICROCOMPUTER 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
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.
North American term for a train driver.
A form of operating an interlocking machine by pushing a bottom at the entrance and the exit of a route.
An interlocking signal at the entrance of an interlocked route. (see also: EXIT SIGNAL)
Abbr. to END OF TRAIN TELEMETRY
Abbr. to EUROPEAN TRAIN CONTROL SYSTEM
ETCS level 1
An intermittent ATP system following the ETCS standard that uses controlled Eurobalises for transmission of control data. (see also: ETCS level 2, ETCS level 3)
ETCS level 2
An continuous ATP system following the ETCS standard that that combines radio-based train control with a fixed block system. (see also: ETCS level 2, ETCS level 3)
ETCS level 3
An continuous ATP system following the ETCS standard that that combines radio-based train control with radio-based train separation based on moving block or virtual block. (see also: ETCS level 2, ETCS level 2)
A standardised balise for use in the European Train Control System
EUROPEAN TRAIN CONTROL SYSTEM (ETCS)
European standard for an interoperable automatic train protection system for European railways. (see also: ETCS level 1, ETCS level 2, ETCS level 3)
1) An 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 the 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)
The percentage of the consumed capacity
A train that does not run on a scheduled train path.
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.
A member of the train crew who provides 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.
The section of track between a flank protection device and the fouling point of the route to be protected.
The locking of flank points in the protective position
A method to prevent vehicles from running into a route, which is cleared for a train movement.
A points that are locked in a protective position to provide flank protection.
FLANK TRANSFER POINTS
Points that are located between an element that provides remote flank protection and the route to be protected.
Another term for a flank area.
FLASHING REAR END DEVICE (FRED)
See: END OF TRAIN TELEMETRY
A shunting method in which vehicles are moved by a locomotive. (see also: GRAVITY SHUNTING)
A classification yard in which classification is done by flat shunting. (see also: HUMP YARD)
An interlocking signal on which fleeting is in effect.
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.
Another term for a classification yard (mainly used outside of North America).
The limit of occupation of converging tracks at turnouts and crossings.
FOULING POINT INDICATOR
A ground mounted sign to mark the fouling point.
Abbr. to FLASHING REAR END DEVICE
A humping control procedure, in which the cuts are retarted only at a few locations (2-3) by powerful retarders. (see also: CONTROLLED CUT)
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.
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.
An interlocking system in which the track elements are represented by logical objects connected to each other in form of the track layout.
A shunting method in which vehicles run down a gradient driven by gravity into their classification tracks. (see also: FLAT SHUNTING, HUMP YARD, GRAVITY 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 shunting locomotives. (see also: FLAT YARD, GRIDIRON YARD)
An type of a gravity yard in which several successive ladders form a gridiron shaped track layout.
A ground mounted small lever frame to enable a group of points to be locally controlled by train or yard crews.
A retarder that serves a group of classification tracks. (see also: MASTER RETARDER)
The time interval between two successive trains.
1) A signal governing entrance to an interlocking.
2) A signal governing entrance to a station track.
HOME SIGNAL LIMITS
A track layout that is protected by opposing home signals. On North American railways, the home signal limits always equal the interlocking limits. On most railways outside of North America home signal limits may contain station tracks and successive interlocking signals.
An artifical hill in a hump yard where vehicles are pushed over to let gravity drive them into the classification tracks.
The procedure of gravity shunting in a hump yard.
A classification yard in which the vehicles run down a hump into the classification bowl. (see also: FLAT YARD, GRAVITY YARD)
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.
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.
An area with interlocked points and signals.
1) Interconnection of signalling components and systems designed so that no conflicting movements can be signalled.
2) An arrangement of points and signals interconnected in a way that each movement follows the other in a proper and safe sequence.
North American Term for the tracks between the outer opposing absolute signals of an interlocking.
North American term for the the trackage within the limits of an interlocking.
A signal that governs a route through an interlocking.
A location from which an interlocking is operated.
A control system of an interlocking area
Another term for a locking table.
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 interlocking area.
Points that are located between two interlocking signals in a way that a train that is waiting at the signal ahead would not clear the points. Intermediate switches must be interlocked both with the signal in rear and with the signal in advance.
An ATP system in which the data is transmitted to the train at discrete points along the track.
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.
An arrangement of tracks and turnouts in which a line is joined by another one.
A method to achieve interlocking between signals and hand-throw points by mechanical key locks.
A group of parallel tracks connected by a ladder track.
A track that provides access to a series of parallel tracks.
North American term for a signal that governs train movements to leave a siding, yard, or branchline.
An employee who operates an interlocking machine (lever frame) under supervision of a train director.
The sequence in which the levers have to be operated to line up a route on an interlocking machine with cascade locking.
A signal in which the aspects are given by the color and/or position of lights.
LINE BLOCK SYSTEM
A block system to enforce fixed block operation by locking signals protecting a block section in stop position.
The headway that results from the blocking time stairways of two successive trains.
The runnings resistance produced by the grade and the curvature of the line. (see also: TRAIN RESISTANCE)
A mechanical locking system that effects the interlocking between the levers of a mechanical, electric or electro-pneumatic interlocking machine.
Another term for a locking table.
A tabular sheet that contains all interlocking dependencies of an interlocking.
A track that is used for passing and overtaking trains. This term is mainly used outside of North America. (see also: SIDING)
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)
An interlocked route governed by a 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.
Another term for route holding.
The tracks that may be used for regular train movements.
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.
A signal that is operated manually.
Another term for a classification yard (mainly used outside of North America).
The first retarder vehicles pass while running down a hump. (see also: GROUP RETARDER)
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.
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.
A pivoting or flexible frog that is operated by a point machine to close the rail gap at the frog in accordance to the route that is set up.
The authority to move a train through a section of track up to a specified limit. (see also: TIMETABLE AUTHORITY)
MOVING BLOCK SYSTEM
A block system in which the track behind a train is cleared continously. (see also: FIXED BLOCK SYSTEM, VIRTUAL BLOCK SYSTEM)
A signal placed between the home signal and the platform to allow a train to pass the home signal while a departing train ahead has not yet completely cleared the platform section.
A signalling system in which the main signals provide information about the clearance of more than one block section.
MULTIPLE HOME SIGNALS
Another term for a signal arrangement in which a home signal is followed by one or more moving-up signals.
MULTI-UNIT LIGHT SIGNAL
A colour light signal with independent light units and every unit using one light.
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 signalling system as a safety overlay. (see also: SIGNAL-CONTROLLED 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 signalling system.
NORMAL RUNNING TIME
The scheduled running time as the sum of the minimum running time and the recovery time.
Abbr. to ENTRANCE-EXIT OPERATION
A part of the infrastructure that can only be occupied successively keeping a minimum headway between successive trains.
A signalling system in which the main signals provide information about the clearance of only one block section.
ONE-TRAIN WORKING (OTW)
An operating procedure for single track branches based on the rule that on the entire line, only one train is allowed at a time.
1)A fixed block system in which the line is cleared (open) in normal state and only blocked as long as a train has occupied the block section.
2) An automatic block system, in which the automatic block signals show a proceed aspect as the normal indication.
Main tracks outside of station areas (not used in North American and British signalling).
An employee who operates signalling appliances. (see also: TRAIN CONTROL OPERATOR)
A system of operating rules and technical appliances to operate trains on a railway infrastructure.
The interlocking between opposing routes leading into the same track section.
The part of an interlocked block system to prevent opposing movements in single line operations. (see also: DIRECTION LOCKING)
Another term for initial delay.
OUTER HOME SIGNAL
An interlocking signal in approach to a home signal that does not directly protect points but that is interlocked with points within the overlap beyond the home signal.
A certain length of track beyond a signal that must not be occupied as long a train is approaching this signal.
Another term for shared overlaps.
Another term for a clock face timetable.
A crosslock that is permanently in effect. (see also: CONDITIONAL CROSSLOCK)
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 points set in opposite positions. (see also: SPECIAL CONFLICTING ROUTES)
A sign that indicates the position of points.
A locking device that mechanically locks the points in a proper position to prevent unattended movements of the points and movable frogs.
A machine that is used to operate points, movable frogs or derailers.
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 (PTC)
An advanced automatic arain protection system that enforces movement authorities, speed restrictions (signal and civil), and protection of roadway workers. This term is mainly used for radio-based systems in North America.
Another term for initial delay.
A signal that displays a stop aspect for protection purposes but that is not used to authorise regular train movements.
Another term for a flank points
Abbr. to POSITIVE TRAIN CONTROL
PURE RUNNING TIME
The shortest possible running time between scheduled stops as a result from a running time calculation.
RADIO-BASED TRAIN CONTROL
A form of operation in which the movement authorities are issued by a radio block centre.
RADIO BLOCK CENTRE
A control centre 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 CENTRE to the train. After the train has cleared the section the token is send back to the radio block centre.
REAR END MARKER
A marker at the rear end of a train.
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.
A time supplement that is added to the pure running time to enable a train to make up small delays.
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 adjacent to the route to be protected.
A speed that allows to stop short of a vehicle or obstruction. This term is mainly used on North American railways.
A trackside braking device used in gravity shunting to control cars running down a hump.
A crossing without movable frogs.
An interlocking appliance that prevents a second operation of a control unit after certain conditions have been met.
A path through an interlocking, along which an authorised movement is to be made.
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 a route node.
ROUTE CONFLICT TABLE
A sheet used for capacity research containing all route conflicts of a route node.
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.
The locking of all points as long a route is established.
A continuous procedure that checks all signalling conditions of a route and transfers the information towards the entrance signal.
The point zone of an interlocking area in which conflicts between different routes may occur.
The selection of a route while a conflicting route has not yet released. After the conflicting route has released the preselected route will be setted up automatically.
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 points and signals are not directly connected by locking sequences. (see also: CASCADE LOCKING)
The release of locked points after the train has cleared the clearing point of a route.
A signalling system in which the facing point signals indicate the route respectively the direction in which the train is being sent.
Another term for a main track.
British term for a normal train movement under control of a main signal.
Points that are installed to provide flank protection.
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 synchronise the schedules of a cyclic interval timetable.
A colour light signal with light units in which the aspect is given by a mechanism placing one of a number of roundels of the colour required, situated near the focus of the lens unit, in front of the lamp.
Another term for collateral delay.
North American term for tracks that are not used for regular train movements.
British term for a signal that governs train movements to leave station limits.
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 POINTS, DUAL PROTECTIVE POINTS
A flank points that may receive flank protection requests for both positions at the same time. See also: SUBSEQUENT FLANK PROTECTION
SELF-SELECTIVE PROTECTIVE POINTS
flank points that would receive competing flank protection requests for both positions from different route elements of the same route. There must determined a position for the points to be locked in.
A signal that gives the indication by the position of movable arms or disks.
A controlled signal that my be switched into automatic mode.
Two or more overlaps simultanously leading into the same track section without causing a route conflict.
A proceed aspect allowing a shunting move to pass a signal.
Movements other than train movements accomplished at restricted speed within designated limits for making up trains, moving vehicles between tracks and similar purposes.
A territory limited by shunting limit boards or other points designated in the operating instructions, where shunting units may enter main tracks. (see also: Yard limits)
SHUNTING LIMIT BOARD
A fixed sign that must not be passed by shunting movements.
SHUNTING SIGNAL, SHUNT SIGNAL
A signal that is used to authorise shunting movements.
An locomotive with or without other vehicles that is authorised to run as a shunting movement.
A locked route used for shunting movements and signalled by a proceed aspect of a shunting signal .
1) North American term for a loop
2) Outside of North America, a shunting track that may not be used for regular train movements.
The appearance of a lineside signal, as viewed from the direction of an approaching train, or the appearance of a cab signal.
British term for an interlocking station.
Another term for an interlocking station.
SIGNAL CLEARING POINT
The point at the end of the overlap a train must have cleared completely to release the block section in approach of the signal.
A form of operation in which train movements are governed by signal indication.
A form of DTC in which the line is equipped with a simplified signalling system as a safety overlay.
A form of operation in which train movements are governed by signal indication.
A form of TWC in which the line is equipped with a simplified signalling system as a safety overlay.
The headway that results from the blocking times of two successive trains in one single block section.
The information that is given by a signal aspect.
British term for a TRAIN CONTROL OPERATOR
A method of capacity research in which, different from analytical capacity research, the running operational processes are modelled (mostly in a computer model). See also: ASYNCHRONOUS_SIMULATION, SYNCHRONOUS_SIMULATION.
A track layout that combines a crossing with two pairs of points to provide slip connections at one side of the crossing.
SINGLE SLIP SWITCH
North American Term for a single slip.
North American Term for a crossing that is combined with movable points for slip connections.
SPECIAL CONFLICTING ROUTES
Conflicting routes that do not differ in the position of points. (see also: PLAIN CONFLICTING ROUTES)
A signalling system in which the signals indicate the speed not to be exceeded by a train.
A points 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.
STAGGERED HOME SIGNALS
Another term for a signal arrangement in which a home signal is followed by one or more moving-up signals.
Old British term for a signal that governs train movements to leave station limits. It is now called a section signal.
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 signalling).
An arrangement 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).
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.
A main track between successive interlocking signals within the same home signal limits (mainly used outside of North America).
Another term for a station area.
STATION TRAFFIC DIAGRAM
A diagram that displays the scheduled occupation of the tracks in large stations and interlockings.
A dead-end track, usually equipped with a bumper.
SUBSEQUENT FLANK PROTECTION
selective protective points that, after the protected route element has released, will subsequently move to the protective position for another route element.
A train having precedence over another train.
A form of overlap protection using a conditional crosslock that allows switching the overlap into another track without cancelling the route.
North American term for a pair of points. In North American railway operations and signalling turnouts are usually referred to as switches.
A diamond crossing with movable frogs.
North American term for shunting.
A method to simulate railway operations by modelling all partial processes of the operation in real time sequences. (see also: ASYNCHRONOUS SIMULATION)
An interlocking system in which the locking between signals and points is achieved in form of a locking table that contains all locking conditions for all routes. Tabular interlocking can be effected by cascade locking or by route-related locking.
A humping control procedure, in which the braking target is the end of the car line in the classification track. (see also: EARLY TARGET SHOOTING)
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 unsignalled and unstaffed passing loops. At the entrance of the section a train gets an order that determines the meeting points with opposing trains within this section.
The runnings resistance produced by the running characteristics of the train. (see also: LINE RESISTANCE)
A manual block system in which the occupation of the block sections is controlled by telephone communication between the block operators.
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
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.
A document that contains the schedules of all trains of a line.
TIMETABLE AND TRAIN ORDER OPERATION
A traditional but today obsolete form of non-signalled 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.
The authority to run a train through the network along a pre-defined train path and under operating conditions specified in the timetable. (see also: MOVEMENT AUTHORITY)
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)
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 driver 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 driver.
An explosive signalling device, placed on the railhead and detonated by a passing vehicle.
See: INTERLOCKING TOWER
TRACK CLEAR DETECTION
A device that detects the occupation and clearance of a track section.
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.
A written form for authorisation of train movements in TWC territory.
TRACK WARRANT CONTROL (TWC)
A radio-based occupation control system for non-signalled 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.
Another term for a dispatcher. This term is used on some railways outside of North America.
The number of trains that are running at the same time on a certain portion of a line.
A diagram that contains the train paths of all trains that run on a line.
The traffic flow multiplied by the average train speed.
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
A locomotive or self-propelled vehicle, alone or coupled to one or more vehicles, displaying a rear end marker with the authority to operate on main tracks in accordance to rules specified for train movements.
The method of authorising train movements.
TRAIN CONTROL OFFICER
South African term for an train control operator.
TRAIN CONTROL OPERATOR
Generic term for an operator who is in charge of authorising train movements. (see also: SIGNALLER, TRAIN DIRECTOR, TRAIN DISPATCHER)
A system that identifies trains which occupy a block section on the display at the panel of the operator or dispatcher.
A number or an alphanumeric code for identification of a train and its schedule.
TRAIN DIRECTOR, TRAIN MOVEMENT DIRECTOR
An train control operator who controls a local interlocking or terminal area. A train director may supervise a number of levermen. This term is mainly used in the North American rules.
A dispatcher who also performs the duty of a train control operator. This term is mainly used in the North American rules.
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.
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.
A time-distance graph that represents the schedule of a train in a traffic diagram.
TRAIN REGISTER BOOK
British term for a train record.
A written sheet in which an operator records all train movements and train messages.
A locked route for the safe passage of a train through an interlocking. (see also: MAIN ROUTE, SHUNT ROUTE)
A document in which the dispatcher records all train movements and movement authorities.
TRAVEL TIME QUOTIENT
The realised travel time divided by the shortest possible travel time.
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.
A principle of protecting opposing movements on automatic block lines in which automatic signals of both directions are cleared in normal state but automatically restored to stop position when an opposing move has entered the line.
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.
Abbr. to TRACK WARRANT CONTROL
An operating mode for double track lines where the tracks may be operated in both directions under block signal control.
Another term for a non-signalled operation.
VIRTUAL BLOCK SYSTEM
A block system, in which virtual block sections are established in the control computer without having physical block sections on the line. (see also: MOVING BLOCK SYSTEM)
WAITING TIME DIAGRAM
A diagram displaying the waiting time as a function of the traffic flow.
British term for a train route with a reduced overlap. A warner route is governed by an approach controlled signal that will only clear after the train has passed a warning aspects at the signal in rear.
A triangle track arrangement consisting of three turnouts or of two turnouts and a high angle crossing.
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)
North American term fo a locomotive in yard service that may occupy main tracks only within 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.
A movement in a yard or within yard limits for shunting purposes.