Glossary

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  • a

  • A2CO – Authority to Change the Organisation is an approved request to restructure a team or department, including changing the reporting lines, location, job titles etc. This topic is covered on Connect within HR Online.
  • A2I – delegated Authority to Incur grants a permanent employee within Network Rail with the ability to allow payments to be made for goods and / or services on behalf of the company
  • Automatic Barrier Crossing. Locally monitored by train crew.
  • A signalling system that allows only one train to be in the Block Section at the same time. Normally, no train is allowed to enter a section occupied by another
  • Alternating Current- Electricity flow
  • Annual Capability Conversation - is the process Network Rail uses to review an employee's track competence and ensure they meet the necessary requirements to hold the competence.
  • An agreement regulated under the Railway Act 1993 setting out the terms and conditions under which companies/operators obtain access to railway track, stations and certain types operators obtain access to railway track, stations and certain types of depots.
  • The charge paid by railway operators for access to rail facilities, that are the subject of an access agreement.
  • Automatic Code Insertion. The means by which, when a train terminates, the next working of its stock is automatically picked up by the signalling areas.
  • asbestos containing material
  • Approved Code of Practice  gives practical advice on how the law is to be complied with
  • Approach Control Signal
  • Automatic Dropping Device - (Pantograph)
  • Access For All
  • Anticipated Final Cost
  • Accident Frequency Rate- measure previously used in industry to measure safety performance
  • Automated Half Barrier crossing
  • Automatic Half Barrier Crossing.
  • Aggregates Handling Depot
  • Approval in Principal
  • Assessment in The Line - a way of checking, and confirming competence though line management
  • As Low As Reasonably Practicable- health and safety term to indicate risk has been reduced to the point where cost exceeds the benefits
  • All level crossing risk model
  • Any Line Open. This is to clarify the requirement that any open line that has the potential to be fouled by the work being carried out on the infrastructure by construction plant or machinery must be assessed and controls put in place to ensure that the works will not affect the safe(...)
  • Asset Management Plan
  • Automatic Open Crossing – locally monitored by train crew
  • Automatic Open Crossing – remotely monitored
  • Area Operations Manager
  • Active or Asbestos Risk Management
  • Automatic Route Setting: information is sent to three computers, two of which have to agree an outcome before the route can automatically be set for the train.
  • Association of Rail Training Providers
  • Area Signalling Centre
  • Associated Society of Locomotive Engineers and Firemen: union which represents many train drivers
  • Auto Transformer Feeder Station
  • Association of Train Operating Companies- which became the Rail Delivery Group (RDG) founded in 2017
  • Authority to work
  • Automatic Train Warning System
  • A specially designated route for the use of personnel when walking to and from their place of work. To include site depots, on site, when carrying out railway duties or going to and from their booking-on point
  • Includes AHBC, ABCL, AOCL and AOCR level crossings as well as those protected by miniature red/ green warning lights
  • A system provided to drivers to give an audiovisual indication in the cab of the status of the signal ahead. This system briefly works as follows; as the train approaches the signal it passes over a ramp between the rails, in which are placed two electromagnets (or a permanent magnet (see(...)
  • It counts the number of train wheels passed through it. provided at starting and ending of a station to conform the total passed station without leaving any boggies
  • This provides the bearing between the axle and on all railway vehicles frame. These were usually simple bearings designed to take the load (for driving wheels) of the alternating piston thrusts as well as the weight of steam locomotive. They were mounted in vertical slides within the frames(...)
  • b

  • Slang for a distant signal.
  • Physical release to allow replacement of a signal route (physical time out).
  • Graded stone sub-base used for drainage and support of the track.
  • Removal of existing ballast using a machine which grades the excavated ballast, returning good stone to the track and taking fine stone and spoil for disposal.
  • A train of wagons to and from work sites conveying track ballast or any other equipment needed within a possession.
  • Slang: A wrong direction move of a train
  • A slang term describing train movements against normal direction.
  • Assisting locomotive that pushes from the back of a train.
  • Signal whose function is to repeat the indication shown by another when the latter cannot be seen by the driver (see Repeater Signal).
  • Biodiversity Action Plan
  • A battery operated lamp with a coloured filter which could be rotated to show white, red, yellow or green aspects.
  • A vehicle used mainly in dangerous goods trains to separate the wagons carrying dangerous goods from other parts of the train.
  • Level crossing at the end of a station platform for use by (or under the supervision of) rail staff only.
  • Metal casting which supports and holds a flat bottom rail on a sleeper.
  • A platform with buffer stops at one end used for trains terminating at the station.
  • Balfour Beatty Rail Maintenance Limited. (Track Renewals).
  • Balfour Beatty Rail Renewals.
  • Business Critical Rules
  • The sequence of bells (block bells) used to communicate between signal boxes using a standardized code
  • Difference between the time a train actually occupies a track circuit and the time recorded in TRUST for the event (see TRUST).
  • A name occasionally used for a specific track circuit.
  • A line that is signalled to take trains in both directions.
  • Building Information Modelling [aka Better Information Management]
  • Equipment fitted into the Driving Cab of some Units (usually the newer rolling stock) which records train speed/brake applications/AWS indications/TPWS activations received etc on each journey. Also know as O.T.M.R., (On Train Monitoring Recorder) the contents of the "Black Box" can be(...)
  • These provide a unique manual system of communication between signal boxes. Using an electric single stroke tapper, messages can be passed between boxes in the form of bell codes
  • An electrically operated indicating device used in a signalbox. The instrument is connected with a similar device in an adjacent signalbox, and can be set to indicate whether or not the block section between the two signalboxes is occupied by a train.
  • Also known as an insulated rail joint. A rail joint in which one rail is electrically insulated from an abutting rail.
  • The section of line between the section signal of one signalbox and the home signal of the next signalbox ahead
  • A device carried by a driver as his authority to run over a single line worked by the Electric Token Block System.
  • A line / or a portion of line that is closed to the passage of trains
  • Slang for a signal
  • Traditional slang for a signaller (the original signallers were actually Railway Police Officers).
  • A wheeled undercarriage pivoted below the end of a rail vehicle
  • A wire connection between the rails to ensure electrical continuity.
  • Panel level crossings are used so that the panels can be removed to allow maintenance of the track. The Bowmac design of panel was the standard product used by BR for most of the 1970s and 1980s.” Sometime mispelt as Bomac. Thanks to Iain King
  • A portable device with lamps to test whether the conductor rail is still energised. This is also known as a Conductor Rail Test Lamp Set.
  • Bridge Strike Nominee - A person who has been certified as competent to implement the procedures for reopening lines after a bridge strike
  • British Transport Police
  • Booster Transformer Return Conductor
  • A rail that has been buckled by heat expansion
  • Railway-vehicle stopping-devices located at the end of a siding or terminating platform
  • c

  • The driver's compartment of a locomotive or railcar, etc
  • Change Acceptance Form
  • The dimension by which the outer rail on a curve is raised above the inner rail.
  • A type of overhead line support
  • Strip on the side coach above the window line where the body side meets the roof
  • Originally a railway telegram code to indicate that one or more trains will not now run, it is sometime still used as slang to mean anything that is cancelled.
  • Capital Expenditure
  • Cardiff Area Signalling Renewal
  • A Catchpit is essentially an empty chamber with an inlet pipe and an outlet pipe set at a level above the floor of the pit. Any sediment carried by the system settles out whilst in the Catch-Pit, from where it can be periodically pumped out or removed. Usually covered by Grill or Man hole cover
  • A pair of sprung trailing points usually located in gradients steeper than 1 in 260. Their purpose is to derail any train running back without authority or out of control. These were running back without authority or out of control. These were a requirement before all vehicles had automatic(...)
  • Term given to overhead wires which support the contact wire on overhead line equipment
  • Computer Based Interlocking
  • Control Centre Incident Log - provides real time updates of all railway related incidents
  • closed circuit television
  • Close Doors platform indicator. A special signal to a train driver that a train is ready to depart from a station.
  • Competence Development Group
  • Construction Design & Management Regulations
  • The area either side of the railway immediately off the ballast shoulder. This usually provides a safe area for authorised workers to stand when trains approach. //
  • A unit of measurement equalling 66 feet, or 22 yards, or 100 links. Equal to 20.1186 metres. Still used on rail infrastructure to indicate location
  • Competent Independent Person
  • CIRAS is an independent, not-for-profit confidential reporting service for the transport sector. People can speak up about their health, safety and wellbeing concerns to CIRAS in complete confidence. CIRAS shares the concerns with the relevant company, and then shares the company response with(...)
  • Customer Information System - station information screens
  • A point operating mechanism, which locks the points by directly clamping the closed switch rail to the stock rail
  • Anything that has the potential to cause harm or damage This includes the potential to: •Harm a person including minor, major injuries, and fatalities •Harm the environment and/or protected species •Damage railway infrastructure, plant, vehicles, tools and equipment. (Not to be Confused(...)
  • Control of Substances Hazardous to Health
  • Controller of Site Safety
  • A term used to describe a specific point of a location, for the point of a location furthest from London.
  • Circuit Protective Conductor
  • Construction Phase Plan
  • Contractors Responsible Engineer
  • Change Request Form
  • A wire stretched across tracks holding the overhead line equipment in this desired position
  • Critical Rail Temperature - The rail temperature to which CWR may be allowed to rise before measures to protect traffic must be taken. The CRT will depend on the stress-free temperature of the rail and the quantity and degree of consolidation of the ballast.
  • Carriage Sidings
  • Cab Secure Radio
  • Current Transformer
  • Small bridge or pipe carrying a stream under a railway or road
  • continuously welded rail
  • Cyclic Top occurs when a dip in a rail causes the suspension of a vehicle passing over it to bounce. The track at the end of the bounce then receives an impact loading that can create a second rail dip and, as that second dip deteriorates with successive impacts, trains will then bounce a(...)
  • d

  • Direct Current. relating to Electrical flow, found in the Third (3rd) and Fourth (4th) rail systems to the South of London and the London Underground network
  • Designated Competent Person(s)
  • A special train fitted with equipment for clearing snow or ice from conductor rails
  • Slang term for Driver’s Safety Device: device on traction rolling stock that will stop the train if the driver becomes incapacitated.
  • Derived from former telegraphic code indicating a failed train
  • Diesel Electric Multiple Unit
  • Designated Earthing Point
  • A complex of sidings, buildings, platforms, etc. where transhipment, stabling, servicing, repairs and other such activities are undertaken.
  • A derailment is deemed to have occurred when the wheel flange has left the rail alignment and the wheel tyre has lifted from the railhead
  • Carrying out full train protection in the event of a breakdown, including the guard walking back a set distance from the rear of the train and placing detonators to alert any trains following. Detonators are also used to mark/protect work site  posssesions
  • A small explosive charge set off by the wheel of a train passing over it. Detonators consist of a small metal cap attached to two soft metal strips which would be used to clip it on top of a rail. Used in emergencies to provide a clear audible warning to drivers. Carried on all trains for use(...)
  • Down Fast Lane
  • Department for Transport
  • Dockland Light Railway
  • Diesel Mechanical Multiple Unit
  • Diesel Multiple Unit
  • Distribution Network Operator - this relates to electrification and power supplies for stations etc.
  • Driver Only Operation
  • Dimensions of Safety
  • That line on a multi-track main line where the direction of travel is away from London- or an allotted City
  • Designated Project Engineer
  • Depot protection System
  • Driver’s Reminder Appliance: a device in the cab to enable the driver to set a reminder that the signal ahead is at danger
  • Director Route Asset Management
  • An S andT term for test on a track circuit, the effect of which will be to make the track circuit show occupied
  • DRS - Dynamic Route Setting
  • Driver’s Safety Device: device on traction rolling stock that will stop the train if the driver becomes incapacitated. Popularly knows as the ‘Deadman’s Pedal’ or ‘Deadman’s Handle
  • Down Slow Line
  • A Network Rail Delivery Unit
  • Delivering Work Within Possessions
  • e

  • Engineering Access Statement (used to be known as Rules of Route) - an agreement for disruptive access with the TOC to allow the planning of services around a possession
  • Electrical Control Operator
  • Electrical Control Room: responsible for control of current in the overhead lines and third rail.
  • Electrical Control Room Operator
  • Electrical Control Room Operator Manager
  • Acronym for Empty Coaching Stock, used to describe passenger trains not currently carrying passengers
  • Examining Engineer’s Nominee (can authorise opening at linespeed for bridge strikes).
  • Equipment Group Identifier
  • Edinburgh - Glasgow Improvement Programme
  • Environmental Impact Assessment
  • Entry into Service
  • A line which is electrified either by 25,000 volt AC overhead lines, or by 750 volt DC conductor rail.
  • Engineer’s Line Reference- a way to identify location/ structure on plans and directories
  • A section of railway line where the surrounding countryside is at a lower level than the line and the ground has been built up to put in the line.
  • Electromagnetic capability EMC aims to ensure that equipment items or systems will not interfere with or prevent each other's correct operation through spurious emission and absorption of the unwanted effects (electromagnetic interference - EMI) from voltages in adjacent cables or equipment.(...)
  • Electric Multiple Unit
  • Electrification and Plant (Power)
  • EPR - Engineers Possession Reminder
  • European Rail Traffic Management System
  • Engineering Supervisor
  • Emergency Speed Restriction- An unplanned reduction in train speed imposed between defined locations along a track. A speed restriction not shown in the Weekly Operating Notice.
  • f

  • Equipment that physically locks points so that they cannot move
  • Facing Points are points which have signalled train movements over them in the facing direction which is the diverging direction where there may be a choice of destination. N.B. only one destination may be valid for a signalled route for example at trap points or at the end of a single or(...)
  • term for a broken down train
  • Frequency Division Multiplexing
  • Slang term for the row of five white lights mounted at an angle above or beside a (cleared) colour light signal to give an indication of route.
  • First Filament Failure: refers to a failure in a signal lamp which has more than one filament for safety. The bulb must be replaced, but the signal works normally and cautioning of trains is not necessary.
  • Steel plate to secure the ends of two rails together (in jointed track).
  • A system of signalling trains manually with flags during breakdown or suspension of the normal signalling system
  • Flank locking is a safety feature, incorporated in the signalling equipment, which then prevents signals operating on routes adjacent to other areas with a failure.
  • A means of protecting movements of trains across junctions by the setting of points (either manually or automatically) that prevent any other unauthorised movement coming into contact with it.
  • A flat spot on the circular tyre of a wheel, usually caused by the wheel skidding along the rail when braking heavily. Causes a characteristic knocking noise and vibration in the vehicle. Also known as square wheels.
  • Freight Operating Company
  • The point on a pair of converging tracks where the two trains would collide side on if allowed to approach together.
  • A colour light signal capable of displaying four aspects. From top to bottom the lights are yellow, green, yellow, and red. A red indication means that the next section contains a train. A single yellow indication (using the lower yellow) means that the next section is clear but there is a(...)
  • The area between the inner running faces of a pair of rails.
  • Facing Point Lock: a device to ensure that points which are facing the approaching trains are locked in position
  • A structure or part of a structure is frangible if it breaks, shears, distorts or yields on impact so as to present a minimum hazard to an object or vehicle hitting it or some other designed stress being placed upon it.
  • Fixed Telecom Network
  • Failure To Stop. Passenger trains failing to stop at booked stations or locations
  • Free Wheel Clearance
  • Fatality Weighted Injuries/Index- method to work out safety performance
  • Free Wheel Passage
  • g

  • A train stalled over a gap in the conductor rail of an electric railway is said to be "gapped". This occurs when the shoes on the train which collect the current have all lost contact with the conductor rail due to gaps left for junctions. Particularly prevalent at complex junctions such as(...)
  • Running rail wall erosion.
  • The General Data Protection Regulation.
  • Global Forest Trade Network
  • Ground Position Light: a low-level shunting signal displaying lights rather than a disc.
  • Common name for the green defective vehicle label, which is put on a railway vehicle considered fit to travel within limitations, ie, only to a place of repair and with restrictions on speed, braking considerations, etc.
  • An area of protection for workers that separates work on the railway line from train movements. One way of arranging such a zone is to stop movements of all trains on all lines at the location concerned.
  • A loose term for any signal set at ground level, typically shunting signals.
  • Global System For Mobile Telecommunications
  • Global System For Mobile Telecommunications for Railways.
  • The distance between a pair of running rails. The standard gauge is 4 foot 8 ½ inches.
  • Give Up Possession Around Train. At the end of a possession, if an engineering train or on-track-machine needs to be moved, Give Up Possession Around Train means that all worksites are given up to allow the train or machine to be moved.
  • Green Zone Access Controller
  • Green Zone Access Manager
  • h

  • Hot Axle Box Detector: a sleeper-mounted temperature detector, which warns a signal box of an overheated bearing as it counts the passing wheels. It indicates which axle is faulty and if one axle or wheel is hotter than the others on the train.
  • A railway station with minimal facilities where trains will usually stop only on request
  • points which are worked manually by an adjacent independent lever
  • Used, mainly by shunters and guards, to indicate required movements to drivers
  • Health and Safety at Work Act- the health and safety law passed in 1974
  • Hand Arm Vibration Syndrome
  • Hazard and Operability Analysis
  • term for the Train Reporting Number. A unique code to identify each train; it is made up of the class of train, followed by its destination and finally its number designated. Used to be displayed on the front of a train.
  • Wire suspended across the tracks and from which the OLE is suspended.
  • High Level Output Specification
  • The first stop signal on the approach to a signal box using the Absolute Block system of signalling
  • A manually operated electrical isolation switch in conductor rail areas for local isolation.
  • A wooden-handled pole used to operate a hookswitch.
  • Sensor mounted on the outside of the rails of a track to detect the increased radiated heat emitted by a defective axle box or bearing.
  • An overheated axle box. Usually the result of insufficient lubrication, or excessive speed
  • HS1 – UK’s first High Speed (over 140mph) line, London – Essex – Kent – Channel Tunnel
  • High Speed 2
  • Health and Safety Executive
  • High Speed Train
  • High Visibility or High Voltage
  • i

  • Insulated Block Joint: a rail joint that separates circuits
  • Integrated Control Centre
  • Industry Common Induction
  • Interdisciplinary Check - a cross check across all disciplines in a project
  • IDD - Interface Definition Document
  • Integrated Electronic Control Centre: a power signalbox where all data displays, safety interlocking, etc. are computer controlled and under normal circumstances trains are signalled automatically according to their TRUST Train ID
  • Also known as a “Spider”. Prevents traction current from entering the signalling system. Prevents traction current from entering the signalling system
  • Ahead of, in the (normal) direction of travel.
  • Behind, in the (normal) direction of travel
  • An unplanned, uncontrolled event which, under different circumstances, could have resulted in an accident
  • Any fixed assets or features of the operational railway which falls within the disciplines of civil engineering, signalling, telecommunications or electric traction power supply.
  • Standing past, ie, inside the protection of that signal.
  • Interlocking of points and signals, through the locking frame in the signal box, which prevents the accidental setting up of conflicting routes.
  • The actual difference in time between trains
  • Infrastructure Projects or Injured Person
  • Infrastructure Safety Liaison Group
  • Interactive Voice Radio System
  • j

  • Joint Network Availability Plans. These are plans for all Network Rail routes agreed between Network Rail and each of the Train Operating Companies (TOCs), especially focussed on the proposed category 'A' routes to uphold the Network Rail promise to reduce disruption during engineering(...)
  • Normal rail in 60ft lengths, but can be 45ft or 30ft lengths
  • A slang term for electricity, especially traction current
  • a cable used for train control or term for a potential suicide
  • The spot at which a branch diverges from the main line.
  • k

  • A generic term to describe a road-rail vehicle.
  • Key Performance Indicator
  • KRS - Key route strategy
  • Kilovolt - 1000v
  • l

  • A layout of facing and trailing crossovers enabling movements across several parallel lines
  • Approximately five weeks in the autumn when leaves fall on the track requiring measures to assure adhesion.
  • A place where a railway and a road cross at the same level.
  • This is the tool that is usually found in the older type of signal boxes. By pulling the relevant levers, the Signaller can operate signals, points, barriers etc.
  • Leaf Fall Contamination: the phenomenon where the action of certain types of leaves being crushed between the rail head and train wheels can cause a build-up of residue on rails can create problems such as wheel slip, impaired braking and failure in the operation of track circuits.
  • A position on a railway track, usually marked by a notice of such, which represents the limit for any shunting movements
  • An indicator on the driver’s desk of an electric train that current is being drawn from the overhead wires or third rail. When the line light is lost (and cannot be reset) it is an indication that there may be a fault. This requires immediate attention to avoid serious damage.
  • The maximum speed at which traffic is allowed to run on a line.
  • Another term for the conductor rail.
  • A cabinet that is found on the side of track full of electrical equipment used for S and T equipment
  • Locomotive
  • Lifting Operations Lifting Equipment Regulations
  • Local Operations Manager
  • A term used to describe a specific point of a location, which is nearest to London
  • A person appointed, when required by the COSS to ensure staff are in a position of safety for a minimum of 10 seconds. He/She will be appointed if the lines/s cannot be blocked and work has to take place whilst the lines staff are working on remain open to traffic.
  • A line parallel to a running line, which by virtue of crossovers between the two lines, enables one train to pass or overtake another.
  • Limit of Shunt Indicator; the limit in which a movement can proceed in the wrong direction. Normally used to get trains behind a signal to then move forward.
  • Lookout Warning System
  • LTIFR Lost Time Injury Frequency Rate Used as a safety measure / indicator
  • London Underground Limited
  • These are the white light directional indicators, advising drivers which way they are being routed
  • Long Welded Rail: usually delivered to renewal sites in 300ft or 600ft lengths (also known as CWR).
  • level crossing
  • m

  • A railway route interconnecting locations of major importance.
  • Double-sided yellow board with two vertical red-yellow flashing lights on one side and two yellow flashing lights on the other used to indicate a work site (possession). There are two types: (i) Possession (red lights) (ii) Work Site (yellow lights). Possession and work site are not(...)
  • To be ‘for cause’ screened for drugs and alcohol following a safety related incident
  • Mechanical and Electrical Engineering (or Engineer)
  • Mobile Elevated Working Platform
  • Term used to describe through tracks in a station where they are not adjacent to the platforms - used for passing non-stop trains through, frequently at high-speed
  • Maintenance Infrastructure Manager In Charge
  • Multi-Lamp Route Indicator
  • Mobil Operations Manager
  • Multi-Purpose Vehicle; a specialist combination set for de-icing, fire fighting, water jetting and applying Sandite
  • Musculoskeletal Disorders
  • A train which has the engines or motors built into it, and therefore requires no locomotive. These units can be coupled together, and driven from the leading cab, when they are said to be running "in multiple".
  • Medium Voltage Line Cover -Provides insulation for catenary, droppers and associated conductors against contact with trees, birds, wildlife or even vehicles and vandalism
  • Miniature Warning lights - used on some footpath crossings
  • n

  • Formerly the National Control Centre- now known as the NOC
  • Not Described Alarm. Indication received on a Train Describer when a Track Circuit/Signal berth becomes occupied and no train I.D. is transposed. Can be caused by a Track Circuit "flicking" or a Train I.D. failing to step from the previous Signal Berth.
  • A Near Miss is the term that describes an unsafe event or act specifically involving a Train or On Track Machinary or On Track plant. To be reported as per Rule Book Not to be confused with a Close Call  which is "Anything that has the potential to cause harm or(...)
  • A portable device with lamps to test whether the conductor rail is still energised. This is also known as a Conductor Rail Test Lamp Set or Box of Eggs
  • Network Operations-  Network Rail department focussed on the operational and maintenance of the Railway
  • Network Rail Online Logistics - the ordering and planning system for all railborne materials.
  • Network Rail Online Logistics - the ordering and planning system for all railborne materials.
  • An arrangement of insulators in the OLE designed to ensure that two sections are kept electrically separate even during the passage of a pantograph
  • National Operations Centre
  • Non-Passenger Carrying Coach Stock; postal and parcel vehicles.
  • Network Rail
  • National Radio Network
  • Network Rail Telecom
  • National Supply Chain
  • National Vocational Qualification
  • Entrance–exit system (signal-box control panel)
  • o

  • Object Contoller
  • Axle Counter Object Contoller
  • A road crossing a railway by overbridge, underpass, or level crossing, where the railway runs through private property.
  • A track section having any part of a train upon it.
  • One Control Switch: a method or route setting
  • ODM - Operations Delivery Manager
  • Overhead Line Equipment: the equipment suspended over the railway for supplying electricity to electric trains.
  • Overhead Line Engineer
  • Overhead Line Neutral Section
  • Overhead Line Equipment
  • Overhead Line Equipment: the equipment suspended over the railway for supplying electricity to electric trains.
  • Overhead Line Equipment Master Index
  • Newer and correct Rule Book term to replace ‘In Rear Of’.
  • Out Of Gauge
  • Outside Party Interest
  • Office of Rail and Road
  • Overspeed sensor located some distance in rear of signal which will activate if train passes over it at too high a speed when approaching the signal at danger.
  • On Track Machine
  • On Track Machine
  • On Train Monitoring Recorder
  • On-Track Plant
  • On Track Plant
  • A term used when a set of points show neither a normal nor a reverse detection
  • An outage is an interruption to a service. Planned outages are those that have been scheduled and agreed in advance and the dates and times are published. These outages are used for preventative maintenance and updates to hardware and software. They are scheduled not to interfere with known(...)
  • A bridge that crosses over the railway
  • An overrun is the unplanned delay in handing back a line to normal traffic after a possession.
  • p

  • Points and Crossings: an alternative abbreviation for S and C (Switches and Crossings).
  • Plant and Machinery
  • A tool made of wood or other insulating material that can be inserted between the collector shoe of an electric train and the live rail to isolate traction current in an emergency.
  • Paladin Data Extract and Reporting System: a versatile train performance measurement facility producing analysis reports focusing on train performance and delay attribution
  • A system for measuring train pantographs.
  • A clip used to hold in place the running rail to the sleeper
  • Also sometimes called a Workstation, this is the Signaller's "workface" where the Routes and Signals for all the trains in the area of Control are set. Some smaller Boxes may have only one or two Panels, whereas Area Signalling Centres/IECC's will consist of a number of Panels each divided up(...)
  • A device fitted to the roof of an electric locomotive or EMU, which is sprung upwards to make electrical contact with overhead wires.
  • Possession Arrival Point
  • Term to describe the planned timing and route of a train. Each train is timed along a section of line at a precise moment. There is a gap before/after other services. This is referred to as "the path". If a train is late it may well lose its path, and then have to be slotted in on ad-hoc(...)
  • A slot of time allocated for a train to travel along the railway
  • Polychlorinated Biphenyls  and equivalent compounds are harmful to humans and animals, particularly those in an aquatic environment or feeding on aquatic animals, because of their toxicity, persistence and tendency to accumulate in body tissue.
  • Principal Contractor Licence
  • Project contingency plan
  • Possession Departure Point or Personal Development Plan
  • Planning and Delivering Safe Work
  • Professional Development and Training
  • Morning peak is any train arriving into London between the hours of 0700 and 1000. Evening peak is any train departing from London between the hours of 1600 and 1900. Also a period where all passenger charter trains run.
  • Paladin Data Extract and Reporting System: a versatile train performance measurement facility producing analysis reports focusing on train performance and delay attribution
  • Slang for giving a Line Clear to the box in the rear when working in Absolute Block regulations
  • A 28-day period, as defined by Network Rail.
  • PERSR - Precautionary Extreme Rainfall Speed Restriction
  • Planned General Inspection: Escalators and all similar public equipment (lifts, travelators etc) are inspected daily by managed station staff as part of the planned general inspection daily regime
  • Person in Charge of a Possession
  • Old Term- Person in Charge of work
  • A person appointed to guide a driver of a train over a line with which he is not familiar or under special circumstances where the movement of trains is restricted. Or a member of staff with sole responsibility for authorising trains to move through an area that is subject to wrong-road(...)
  • When part of a set of Points or crossover are removed preventing crossing movements being made through them and effectively making the route affected set for "straight running" only.
  • Possession Limit Board
  • Position Light Junction Indicator
  • Patrolman’s Lockout Device (trackside staff protection system); a device which, when used with the Signaller’s permission, returns a bi-directional line to a single directional line
  • Personal or Physical Needs Break: a guaranteed break in a Driver’s turn of duty when  free from duty.
  • Point Operating Equipment
  • The movable parts of the rails in a set of points, typically a pair of linked tapering rails that can be moved laterally to allow a train to pass from one line to the other.
  • An electric heater to melt snow and ice that might otherwise impede correct operation of points
  • A single or double solenoid device attached to a turnout so that the points may be operated electrically from a remote location
  • A junction of two railway lines that can be set to guide a train onto one of two alternative routes, or allow two lines to merge into one. Points can either be in "Reverse" or "Normal". Reverse being : The position of points where the reversed position indicates that the points are set for the(...)
  • A movement which runs through a trailing set of points which are not set in the correct position for the movement
  • Rail Plant Operating Company in Possessions Licence
  • Possession Optimisation Manager
  • Periodical Operating Notice: a bi-monthly publication, which contains all current amendments to the books of Rules and Regulations and certain miscellaneous notices.
  • Entrance to a tunnel or a type of overhead line support
  • Plant Operators Scheme
  • Plant Operating Scheme
  • Person operating signalling equipment
  • Position Light Ground Signal
  • When a section of track is required for maintenance and trains cannot run, it is handed over by the operators to the engineers, who take "possession". Special protective measures are used to prevent access by unauthorised trains. When the track is returned to the operators, the engineers "give(...)
  • A ceramic stand that supports the conductor rail in DC areas.
  • Points operated by means other than mechanical (eg electric motor, hydraulics or compressed air).
  • Personal Protective Equipment
  • Public Performance Measure
  • Possession Planning System - it manages the process for booking and recording of national engineering and access requirements (possessions, worksites, temporary speed restrictions).
  • Moving a train using a locomotive at its rear
  • In a specialised sense, used for the rules governing the protection given to a train, which stops in an unusual location or becomes derailed, to stop another train hitting it.
  • Power signal box
  • Project Safety Leadership Group
  • Permanent Speed Restriction
  • Personal Track Safety
  • Personal Track Safety- Competence certificate to enable as to correctly determine their responsibilities and duties when working ‘On or Near the Line’ on the Railway Infrastructure
  • -Operate signal to give a proceed or a less restrictive indication.
  • A method of locomotive-hauled train in which the locomotive is permanently attached at one end of the train and when at the rear is remotely controlled from a driver’s cab built into the leading vehicle (see DVT). Its advantage is that run-round moves or turnover locomotives are unnecessary.
  • Permanent Way. The track of a railway line; the ballast, sleepers and rails.
  • q

  • Trains with British Transport Police on board to combat trespass and vandalism. Also applies to a pathway not always utilised (runs required, for example, a Sandite train).
  • A railway route in which two sets of tracks are provided for each direction of travel.
  • r

  • Route Availability or Right Away platform indicator
  • A special signal to a train driver that a train is ready to depart from a station
  • Rail Accident Investigation Branch. The RAIB is the government railway accident investigation organization for the UK. It investigates railway accidents/ incidents on the UK’s railways involving train movements to improve safety, not to establish blame.
  • An individual certificated by the RAIB (probably a Network Rail employee) who will assist in recording evidence at an incident site. May well be first RAIB representative to attend site.
  • A complete set of (loco-hauled) coaches.
  • Route Access Manager Route Asset Manager or Reliability Availability Maintainability Depends on context, can be either: Route Access Manager (e.g. buildings, OLE, P&D, Telecoms), Route Asset Manager, or Reliability Availability Maintainability (in connection with(...)
  • Railway Contractors Certificate
  • Railway Contractors Certificate
  • Rail Delivery Group
  • The delay to trains resulting from an earlier train delay.
  • A site of work that is on or near the line, where the trains are still running
  • A site of work if it is on or near the line and it has not been possible to set up a Green Zone
  • A place of safety in tunnels and alongside high speed lines where employees can stand in safety; also A dead end siding allowing trains to be shunted off the running lines
  • Since 2019 Network Rail is geographically split into 5 Regions Scotlands Railway Southern Wales and Western Eastern North West and Central
  • Signallers can regulate the train service by giving priority to one train over another.
  • Officer appointed by the Government to regulate the railway industry
  • An electro-mechanical switching device used in many types of signalling systems; it “relays” instructions to signals and points. Relays are now being superseded by Solid
  • A secondary line which runs alongside a main line.
  • Radio Electronic Token Block  is a system of railway signalling used in the United Kingdom. It is a development of the physical token system for controlling traffic on single lines. On arrival at a "token exchange point", the driver reports his/her position to the(...)
  • A track on which traffic may be worked in either direction (bi directional)
  • Radio Frequency IDentification
  • Miniature red/green warning lights (at level crossing).
  • Rail Industry Assurance group
  • Rail Incident Commander: strategic level overview of incident management.
  • Reporting of Injuries, Diseases or Dangerous Occurrence Regulation- legislation guiding the reporting of injuries.
  • Rail Industry Environment Forum
  • A term used for the signal given by a guard to a driver that he is permitted to depart
  • A mode of failure, which causes a piece of equipment to cease functioning without compromising the safety of trains.
  • Rail Incident Officer: normally a Network Rail employee who takes control at the scene of a rail incident or accident. Works with Incident Officers from emergency services to co-ordinate the tasks at the scene.
  • Route Managing Director
  • Rail Management Engineer
  • Railway, Maritime and Transport Union
  • Rail Operator
  • Slang term for the track or a train pathway along the route
  • - Railways and Other Guided Transport Systems (Safety) Regulations
  • Anything with wheels on it which can run on the track including locomotives, carriages, goods wagons, and maintenance vehicles.
  • A term used when a member of the train crew reports a “bumpy” ride at a given location
  • area of operation within Network Operations
  • Responsible Person On Site
  • RRAP – Road Rail Access Point
  • Road Rail Vehicle. A vehicle that can travel on the road under its own power and also travel on the rails by virtue of a rail wheel guidance system
  • Return Screening Conductor
  • Residual Switch Opening
  • Rail Safety and Standards Board
  • A book, which incorporates most of the rules to be observed by general railway staff for the safe operation of the network. Published in Modules by the RSSB. Updated every June and December
  • Rules agreed with train operators under which speed restrictions or temporary line closures can be imposed for maintenance purposes
  • Unauthorised passing of a signal at danger, or overshooting a station or designated stopping point.
  • A run-through is an unintended movement of a rail vehicle through a set of points in the trailing direction when the points are set against the movement being carried out.
  • Running surface of the rail. Can also apply to an interchange point between road and rail.
  • s

  • Signalling and Telecom
  • A mixture of sand and antifreeze, used for assisting traction adhesion during extreme weather. Sandite S4 also contains steel shot to assist track circuit operation
  • Sectioning Auto-Transformer Site From Wikipedia: In UK railway applications, it is common to power the trains at 25 kV AC. To increase the distance between electricity supply Grid feeder points they can be arranged to supply a 25-0-25 kV supply with the third wire (opposite phase) out of reach(...)
  • A loading gauge that permits operation of road-rail swap body vehicles
  • switches and crossings the specially machined rails designed to permit trains to transfer between tracks.
  • Supervisory Control and Data Acquisition
  • A lump of wood either placed in an open switch of points to prevent movement, or on a rail under a wheel to prevent a vehicle from being moved.
  • Showing Clear When Occupied
  • Signals usually worked mechanically by wire from a signal box’s lever frame, but can be electrically operated; these are mechanical arms rather than coloured lights
  • Sentinel is the organisation set up to administer Track safety competence
  • A refinement of ‘Interlocking’ that ensures signals are operated only in a certain order.
  • Seasonal treatment on-Line. It’s a database that is used to manage the national seasonal infrastructure treatment plan
  • Meaning of So Far As Is Reasonably Practicable (SFAIRP): A guideline for rail organisations to assist them in developing a decision making framework
  • Safety, Health and Environmental Leadership Team
  • Term used as a shortened version of "collector shoe" to denote a third rail current collection device mounted on the bogie of a direct current electric train.
  • A slang term for detonators
  • This is a short distance stock movement for the purpose of re-positioning, re-marshalling or berthing of trains.
  • A single piece of track attached to a mainline or headshunt at one end only. The other end will usually be terminated with a buffer stop so as to ensure that trains do not run off the end.
  • Visual indication passed to a train driver to advise the speed, direction or route of the train. There are almost as many types of signals as there are railways but they fall into the following main categories:1) handsignals - used mainly where there are no fixed signals or where the fixed(...)
  • The control centre for signalling trains. This is where the signallers control the movements of trains by signals.
  • A framework suspended across several train tracks, and upon which many signals may be mounted
  • Simplified Bi-Directional Signalling: signalling provided to allow trains to run in the “wrong” direction during engineering work, line blockages, etc. without resorting to pilotmen
  • Safety Improvement Programme
  • Station information and security systems - customer information screens etc. (also partly known as CIS
  • Commonly used term to describe the space between two adjacent tracks
  • A beam spanning the track, which is used to support the rails. Originally wooden but concrete sleepers are generally used now. Steel sleepers have also been used occasionally
  • Standard Length Unit: the measurement of the shortest wagon (21ft); used to describe the length of vehicles and loops so it is known if trains can be accommodated
  • Single Line Working
  • Signal Monitoring And Reporting to TRUST: provides information automatically on actual train running.
  • Signal Maintenance Testing Handbook
  • Signal Past at Danger. There are various degree and type of SPADs catergorised A-D
  • A train that was not in the working timetable, and had been programmed via a special traffic notice
  • A Blanket Emergency Speed restriction is one that is applied over a wide area in response to, for example, bad weather. Advice to drivers and signallers on when a blanket emergency speed restriction is imposed or withdrawn is via Operations Control. If the restriction is imposed for more than(...)
  • Signal Post Telephone. A telephone located on or near a signal where the driver can directly communicate with the signaller. Also used for any other railway staff to contact the signal box.
  • A piece of railway line which branches off from a main line. Can be used as an alternative route if there is an incident occuring on the main line
  • Self Supporting Anchor (for OLE structures)
  • Special Site Inspection or Investigation
  • Special Stop Order. Passenger trains stopping additionally at stations.
  • Safe System of Work Planning/Pack - these are plans that are to ensure a safe system of work is in place before work starts
  • Site of Special Scientific Interest
  • Safety, Technical Engineering directorate within Network Rail- replaced with the Technical Authority (TA) in 2020
  • A machine developed to maintain the trackbed.
  • The process of stretching continuously welded rail so that the stress-free temperature of the rails is within the required so that the stress-free temperature of the rails is within the required range (21–27°C).
  • A construction such as a bridge (rail, road, foot or equestrian), viaduct, retaining wall, tunnel or similar, signal or electrification post or gantry, station construction such as a platform wall, track drainage manhole or cable pit, and any other construction on Network Rail Controlled(...)
  • A building or compound containing electrical switchgear and equipment which supplies electricity to the conductor rails.
  • A point in which the flangeway at the nose is arranged to open or close according to which way the points are set, to provide a smooth passage for the train wheel.
  • The moving portion of rail on each side of a set of points.
  • Safe Work Leader - person accountable for safe delivery of work within a worksite
  • Safe Work Manager
  • Site Waste Management Plans Regulations 2008 require that any person intending to carry out a construction project in England with an estimated cost of greater than £300,000 must prepare a site waste management plan – an ‘SWMP’. This must be updated in accordance with the Regulations, with(...)
  • t

  • Tresspass & Vandalism. Now called Railway Crime
  • within the railway TA is Technical Authority- a directorate of Network Rail
  • Train Arrived Complete - The authorised memeber of traincrew will operate the Train Arrived Complete switch located on the platform on which a train has arrived complete with tail lamp, under absolute block signalling when the train has not passed the signal box for the signaller to observe(...)
  • A permanent-way maintenance machine, consisting of a number of vibrating rods, which, when dug into the ballast, cause the ballast material to pack more firmly under the track
  • Process that compacts ballast under sleepers to maintain the correct geometry of the track.
  • Tilt Authorisation and Speed Supervision system - to authorise tilting operation only on tilt cleared routes and to prevent the line speed being exceeded when these trains are operating in tilting mode.
  • Task Briefing Sheet
  • Track Circuit Block- A modification of the Absolute Block System, employing track circuiting throughout. A train may proceed, as soon as the line is clear, to the next stop signal plus the required overlap beyond that signal
  • Tunnel Condition Marking Index
  • Track Circuit Operating Device. Used to activate track circuits so that they show occupied
  • Train Control System
  • Identifies the term given to the central space on a four-track railway (may actually be less than ten feet).
  • A station found at the end of a railway line where departing trains have to travel back in same direction out of the platforms as that from which they arrived
  • Directional lights found on approach to major stations
  • A system of railway electrification in which the traction current is picked up by a skate or shoe which makes contact with a third rail located between or to one side of the running rails, and returned via both or either of the two running rails.
  • A colour-light signal capable of displaying three aspects.From top to bottom the lights are green, yellow, and red. A red indication means that the next section contains a train. A yellow indication means that the next section is clear but there is a train in the following one. A green(...)
  • Thameslink Programme
  • Traction Maintenance Depot
  • Temporary Non Conformance /Compliance
  • Train Operating Company
  • Total Operations Processing System: a prime source of train operation data such as destination, load and location. TOPS provide a comprehensive system for monitoring a train’s complete movement cycle from workshop and maintenance
  • Train Operating Warning System: gives audible warning to those working on the track of the approach of the train
  • Take Possession Around Train.  At the start of a possession, an engineering train or on-track-machine may be moved into position, before any worksites are set up. The term for this is Take Possession Around Train.
  • Two sets of two electronic loops are set in the track before signals where a SPAD would be most likely to put a train into risk of being involved in a collision. The loops are energised when the signal is red and emit electromagnetic fields. When an antenna on the train detects the field(...)
  • An electrical circuit that includes an insulated section of track. A train occupying the track will complete the circuit by connecting the two rails together via its wheels and axles thus signaling the trains occupation of that section of track. Track circuits are designed to detect the(...)
  • Track Renewal and Maintenance Machine
  • Train Register Book
  • Electrical switch operated by the train wheels, often for level crossing approach.
  • Train Ready To Start "Train Ready To Start". The platform staff (or driver, when in a siding) will operate the Train Ready To Start switch, located on the platform (or siding) when the train is ready to depart for its journey
  • Train Running System (TOPS - Total Operations Processing System): computer system, which records details of train operational data as compared with schedule, supporting the logging of delays and associated attribution process.
  • The delay attribution system for recording the size and reason for delays recorded by TRUST.
  • Track Safety Alliance
  • Technical Specifications for Interoperability The development of Technical Specifications for Interoperability (TSIs) are the responsibility of the European Railway Agency (ERA).
  • Temporary Speed Restriction
  • Train Stop Sensor which is located immediately on the approach side of a signal and will activate if a train passes it when signal is at danger
  • Transport Salaried Staff Association union
  • Twin Track Cantilever - a form of OLE structure with one post and carrying two sets of catenary from one cantilevered boom
  • Transfer of Undertakings (Protection of Employment) Regulations 1981; legislation that protects earnings and conditions when employees transfer from one employer to another
  • The track configuration enabling trains to change from one track to another (widely called Points).
  • Track Visitors Permit- permit to allow temporary accompanied a