Glossary of Terms


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IBJ
Insulated Block Joint


Disciplines:
Abbreviated term for Insulated Block Joint.
Alternative
Disciplines: Electrical, Infrastructure
IECC
Integrated Electronic Control Centre


Disciplines:
Abbreviated term for 'integrated electronic control centre'.
Alternative
Disciplines: Train Control
IFS
Individual Function Switch


Disciplines:
Abbreviated term for 'individual function switch'.
Alternative
Disciplines: Train Control
Illegal Signal Indication
A signal indication that is inconsistent with the signal aspects and indications used on the network, or the indications of adjoining signals and the known condition of the line, or what is known about occupancy of the line.

Refer Wrong Side Failure

Preferred
Disciplines: Train Control
Illuminated
The internal or external illumination of signalling equipment.

Regional
Disciplines: Train Control
Illuminated Diagram
A signal-box diagram giving, by means of illumination, automatic indications of the occupancy or otherwise of the tracks within the controlled and/or adjoining areas. It may also include the automatic indication of the signal aspects and/or positions and the positions of points, etc.

Regional
Disciplines: Train Control
ILWS
Inductive Loop Warning System


Disciplines:
Abbreviated term for 'inductive loop warning system'.
Alternative
Disciplines: Train Control
Impact Analysis
Process for analysing where the specifics of a proposed change impact on rail safety taking into account the accredited rail organisations risk register, safety performance and accident/incident register.

Preferred
Disciplines: ALL Disciplines
Impedance Bond, Neutral Leads
Cables connecting the mid-point of an impedance bond in one track circuit to the mid-point of an impedance bond on the adjoining track circuit or to the traction rail of an adjoining single rail track circuit.

Regional
Disciplines: Electrical, Train Control
Impedance Bond, Side Leads
Cables each side of the impedance bond connecting the bond to the adjacent rails of the track circuit.

Regional
Disciplines: Electrical, Train Control
Impedence Bond
A trackside mounted device, connected across running rails, which will allow a free flow of traction current between traction return rails and provide a connection for earthing the traction return rails and rail side structures without introducing any imbalance in the signalling track circuits.

Preferred
Disciplines: Electrical, Train Control
In Advance
A position along the line ahead of a given position, when facing the direction a train travels on the line. The area through which a train travels after passing a given position.

Preferred
Disciplines: Train Control, Operations
In Clear
A train is In Clear when it is within the clearance point boards for crossing purposes, or when the entire train is within station protection and is not foul of an adjacent track.

Preferred
Disciplines: Train Control, Operations
In Effect
Activate, become current, in force.

Preferred
Disciplines: ALL Disciplines
In Rear
A position along the line behind a given position, when facing the direction a train travels on the line. The area through which a train has travelled before reaching a given position.

Regional
Disciplines: Train Control
Refer to Approach To.
Regional
Disciplines: Train Control
Related Term: Approach To
In-bearer Points Mechanism
An arrangement of points in which the drive and detection connectons are located within purpose-built hollow bearers, rather than in the spaces between bearers. The drive mechanism and detector may also be housed in the bearers.

Regional
Disciplines: Train Control
In-cab Signalling
A display in the driving cab of a train, showing permissible speed or extent of movement authority, instead of or supplementing lineside signals.

Preferred
Disciplines: Train Control, Operations
In-field Protection
One or more devices approved by Rail Infrastructure Managers that provide warning to protect rail traffic crew and workers.
The device or devices may be used in conjunction with signalling or blocking facilities.

Preferred
Disciplines: ALL Disciplines, Operations
In-sleeper Point Machine
A hollow steel sleeper containing the drive and lock mechanism (usually claw lock, pawl lock or similar) and the detection connections. The sleeper may also contain the operating mechanism and detector or these may be attached to the end of the sleeper.

Regional
Disciplines: Train Control
Refer to 'in-bearer point mechanism'.
Alternative
Disciplines: Train Control
Incident
An uncontrolled, unplanned, undesired event that under different circumstances has the potential to result in loss. Although loss has not occurred, the events leading up to an incident can be identical to an accident. An incident is commonly known as a near miss.

Preferred
Disciplines: ALL Disciplines
Incident Reporting System
The computer database system for recording and responding to incidents.

Preferred
Disciplines: ALL Disciplines
Incident Response Co-ordinator
The person or persons nominated by a rail organisation to provide 24 hour, 7 day point of contact and to provide incident response initiation within that organisation.

Preferred
Disciplines: ALL Disciplines
Independent Position Light Signal
A position light signal not associated with a main signal.

Regional
Disciplines: Train Control
Independent Switches
Points with each point switch of the pair of point switches separately and independently interlocked and controlled.

Regional
Disciplines: Train Control
Indication Lock
An electric lock connected to a mechanical lever of an interlocking machine to prevent the full movement and release of interlocking by the lever until the signals, points or other units operated, or directly affected by such lever, are in the proper position.

Regional
Disciplines: Train Control, Electrical
Indicator
A device used to convey information, usually visually.

Regional
Disciplines: Train Control
Indirect Interlocking
Interlocking between two movable parts not effected directly in the system constituted by these two parts, but existing nevertheless by reason of the presence of direct interlocking between the parts in question and another part external to that system.

Preferred
Disciplines: ALL Disciplines
Indirect Opposing Route Locking
Two complete routes that are conflicting in that they require at least one set of points in a different position. However, cancellation of one route with a train part way through the route releases the locking on these points which, when they become free, create the conditions for direct opposing locking to be set. Indirect opposing locking is applied to prevent the setting of the route that has become opposing.

Regional
Disciplines: Train Control
Individual Wheel L/V
The ratio of the lateral force to the vertical force between the wheel and rail on any individual wheel that is used as a measure for the likelihood of a vehicle to derail by flange climbing.

Preferred
Disciplines: Rolling Stock

Preferred
Disciplines: ALL Disciplines, Infrastructure
Infrastructure Maintenance Rolling Stock
Track machines and road-rail vehicles. Also known as on 'track vehicles'.

Preferred
Disciplines: ALL Disciplines, Rolling Stock
Inhibit
To avoid/suppress the initiation of a driver supervisory system brake application.

Non-preferred
Disciplines: Rolling Stock
Refer to 'Suppression'
Alternative
Disciplines: Rolling Stock
Insert (sleeper)
One or more of the fastening components that is cast in the sleeper at the time of manufacture.

Preferred
Disciplines: Infrastructure
Instruction Sign
A sign, near or fixed to a signal, bearing directions to rail traffic crews.

Preferred
Disciplines: ALL Disciplines, Operations
Instrumented Wheelset
An item of test equipment which includes a wheelset equipped with strain gauges and processing electronics such that the lateral and vertical forces between each wheel and rail can be measured while the rolling stock is in motion.

Preferred
Disciplines: Rolling Stock
Insulated Block Joint
A joint in which electrical insulation is provided between adjoining rails. Assembled from insulating end posts, ferrules and side pieces or manufactured as a glued insulated joint.

Regional
Disciplines: Electrical, Infrastructure
Insulated Overlap Span
An overlap span arranged with insulation between the two sections of overhead line equipment so that by the opening of an isolator or by the removal of connections, one section may be electrically separated from the other.

Preferred
Disciplines: Electrical
Insulated Rail Joint (IRJ)
A rail joint manufactured from components and assembled such that the joined rails are electrically insulated from each other.

Preferred
Disciplines: Electrical, Infrastructure
Insulated Section
Stretch of track one or each rail of which is insulated.

Preferred
Disciplines: Electrical, Infrastructure
Insulating Ferrule
In insulated joints with metal fishplates, ferrules provided to insulate the fishbolts.

Preferred
Disciplines: Electrical, Infrastructure
Insulating Side Plate
In insulated joints with metal fishplates, plate provided to insulate the fishplate.

Preferred
Disciplines: Electrical, Infrastructure
Insulation Channel
A preformed channel manufactured from insulating material which is installed between the rails and fishplates to provide electrical isolation between the fish plates and rails at insulated joints.

Preferred
Disciplines: Electrical
Insulation End Post
The insulating material of similar cross section to rail which is installed between rail ends to provide electrical isolation between one rail and the other at an insulated joint.

Preferred
Disciplines: Electrical
Insulation Ferrule
A tube manufactured from insulating material which is fitted to a fastener to provide electrical isolation between the fastener and the rails and or fish plates at an insulated joint.

Preferred
Disciplines: Electrical
Insulation Resistance
The electrical resistance offered by the insulation on any current-carrying part or conductor.

Regional
Disciplines: Train Control, Electrical
Insulation Test
This is a test of the resistance of the insulation between an electrical circuit conductor and 'earth' or directly between the conductors of two separate electrical circuits. The test is made at a specified voltage which is high compared to the circuit voltage.

Regional
Disciplines: Train Control, Electrical
Intact
A train is Intact when all the vehicles are coupled together and the lead locomotive and the last vehicle are displaying the correct signals.

Preferred
Disciplines: Operations, Train Control
Integrated Electronic Control Centre (IECC)
A computerised signalling control centre that usually incorporates SSI and ARS. Signalling indications, train descriptions and other information are displayed on VDUs, and routes are set by tracker ball, keyboard or automatically by ARS.

Regional
Disciplines: Train Control
Integration
the act of blending or combining into an integral whole

Preferred
Disciplines: ALL Disciplines, Operations
Interchangeability
the ability to put (each of two) things in the place of the other

Preferred
Disciplines: ALL Disciplines, Operations
Interface Coordination Plan
An agreement between parties managing an interface which sets out the responsibilities of each party.

Preferred
Disciplines: ALL Disciplines
NOTE: May also be referred to as a Safety Interface Agreement.
Alternative
Disciplines: ALL Disciplines
Interim Accreditation
Refer to Temporary Accreditation.

Alternative
Disciplines: Operations, Infrastructure
Related Term: Temporary Accreditation
Interlinking
Box-to-box controls to ensure enforcement of electrical
sequential locking, proving of home and distant on and berth clear before transmitting line clear and the acceptance of second train. sequential locking, proving of home and distant on and berth clear before transmitting line clear and the acceptance of second train.

Regional
Disciplines: Train Control
Interlock
Interaction of equipment controlling points and/or signals to prevent conflicting movements of signals, and to make sure routes are set correctly.

Preferred
Disciplines: Train Control, Electrical
Interlocked Points
A set or series of points the control of which is interlocked with other functions of the interlocking.

Preferred
Disciplines: Train Control
Interlocking Area
An area equipped with interlocked points and/or signals.

Preferred
Disciplines: ALL Disciplines
Interlocking Automatic Coupler
An automatic coupler with a different profile on the coupler head to prevent over-riding and/or telescoping in the event of collision.

Preferred
Disciplines: Rolling Stock
Interlocking Frame
An alternative term for Lever Frame.

Regional
Disciplines: Train Control
Interlocking Key
A means of obtaining the effect of interlocking by the release and transfer of a captive key and without the physical connection between the items of equipment concerned.

Regional
Disciplines: Train Control
Interlocking Machine
Equipment used to operate or control interlocked points and signals.

Preferred
Disciplines: Train Control
Intermediate
Between two others.

Preferred
Disciplines: ALL Disciplines
Intermediate Block Home Signal
A signal controlling the exit from an intermediate block section.

Regional
Disciplines: Train Control
Intermediate Block Section
A train detected portion of line between the section signal and the intermediate block home signal, both of which are operated from the same signal box. The intermediate block section is situated between adjacent signal boxes so as to improve overall headway.

Regional
Disciplines: Train Control
Intermediate Car

Alternative
Disciplines: Rolling Stock
Intermediate Electric Train Staff Instrument
Provided at junctions and sidings within an electric train staff section to restore the staff instruments at each end of the section to phase when a train has been admitted to the branch line or stored in a siding. The intermediate electric train staff instrument also allows a train to enter an electric train staff section from a branch line or siding.

Regional
Disciplines: Train Control, Operations
Intermediate Siding
A siding located within a section generally used for purposes other than crossing or passing of rail traffic.

Preferred
Disciplines: Train Control, Operations
Intermediate Signal
An intermediate signal is a fixed signal used to divide a section to facilitate the movement of following rail traffic.

Preferred
Disciplines: Train Control, Operations
Intermediate Token Instrument
A mid section token instrument, usually located at a ground frame and associated with shutting-in facilities.

Regional
Disciplines: Train Control
Intermediate Vehicle
A passenger vehicle without a drivers compartment and not intended or equipped to operate as the lead vehicle in a MUC or MCS consist. Intermediate vehicles may be powered or non-powered.

Preferred
Disciplines: Rolling Stock
Intermodal Traffic
Freight moving via at least two different modes of transport, eg rail to road, rail to sea etc. Used to describe freight in modules which can be transported by more than one mode (rail, road, sea or air). The usual form of intermodal freight is containerised freight, which has proven to be the most convenient to transfer between modes. Because of this the terms intermodal and containerised are often interchanged.

Preferred
Disciplines: ALL Disciplines, Operations
Interoperability
A term used to mean the possibility of uninterrupted movement of trains from differing countries (states) across international (state) borders.

Regional
Disciplines: Train Control
Is the ability of a process, system or a product to work with other process, systems or products.
Preferred
Disciplines: ALL Disciplines
Interoperability Component
means any part, group of parts, subassembly or complete
assembly of equipment that is incorporated or intended to be incorporated into a subsystem upon which the interoperability of the railway depends directly or indirectly.

Preferred
Disciplines: ALL Disciplines
Interrupter (track Circuit)
Device designed to break the feed current to a track circuit in certain cases (derailment of a train at catch points, etc).

Preferred
Disciplines: Electrical
Intersection Of Heads (points Or Crossings)
The position on crossingwork at which the inside of the rail head, at full section, contacts the running edge of the other rail head. It corresponds to the commencement of head side machining.

Preferred
Disciplines: Infrastructure
Intersection Point (IP)
The intersection point of the centre lines of two tracks, tangent from the crossing.

Preferred
Disciplines: Infrastructure
Interstate Standard Gauge Network
Standard gauge track, mostly under control of ARTC, connecting the mainland Australian state capital cities.

Preferred
Disciplines: ALL Disciplines, Infrastructure
Refer to DIRN
Alternative
Disciplines: ALL Disciplines, Infrastructure
Related Term: DIRN
Interstate System
Any railway system or part of a railway system, designated by its owner as a route to be used for movement of interstate traffic.

Preferred
Disciplines: ALL Disciplines
IP
Intersection Point


Disciplines:
IPITC
Intelligent Processor Island Track Circuit


Disciplines:
Abbreviation for 'intelligent processor island track circuit'.
Alternative
Disciplines: Rolling Stock
IRJ
Insulated Rail Joint


Disciplines:
Abbreviated term for 'insulated rail joint'.
Alternative
Disciplines: Infrastructure, Electrical
Irregular Incident
An occurrence on a railway or tramway system that is not an accident but involves a breach of the operating rules or procedures of the system.

Preferred
Disciplines: ALL Disciplines
Irregular Signal Indications
A signal which is displaying a non-valid indication, e.g. a colour light signal which is displaying no light or an irregular combination of colour lights or irregular flashing lights, or a semaphore signal with an abnormal signal arm indication which in combination with other failures may bring the system to an unsafe condition.

Regional
Disciplines: Train Control
Refer Wayside system failure.
Alternative
Disciplines: Train Control
Isolated
Disconnected from all possible sources of electricity supply by means of visible breaks or length of insulation of value appropriate to the voltage.

Preferred
Disciplines: Electrical
Isolated Overhead Wiring Sections
An overhead wiring section disconnected from all possible sources of supply.

Preferred
Disciplines: ALL Disciplines, Electrical
Isolation
The disengagement of a system by an authorised procedure either for maintenance purposes or to enable the rolling stock to continue to operate under special conditions when the device has failed.

Preferred
Disciplines: Rolling Stock, Operations
Isolation Protection
Measures to prevent the energisation of isolated/de-energised overhead line equipment by the passage of pantographs.

Preferred
Disciplines: Electrical, Operations
Issue
To give or send copies of authorities, warnings, notices and Network publications to affected Competent Workers by voice, hand delivery or electronic means.

Preferred
Disciplines: ALL Disciplines, Operations
ITSR
Independent Transport Regulator (NSW)


Disciplines:
Abbreviated term for 'Independent Transport Regulator (NSW).
Alternative
Disciplines: ALL Disciplines