A2COA2CO – 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.
A2IA2I – 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
ABCLAutomatic Barrier Crossing. Locally monitored by train crew.
Absolute Block SignallingA 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
ACCAnnual 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.
Access AgreementAn 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.
Access ChargeThe charge paid by railway operators for access to rail facilities, that are the subject of an access agreement.
ACIAutomatic Code Insertion. The means by which, when a train terminates, the next working of its stock is automatically picked up by the signalling areas.
ALOAny 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(...)
ARSAutomatic 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.
Authorised Walking RouteA 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
Automatic Warning SystemA 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(...)
Axle CounterIt 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
AxleboxThis 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(...)
BacklockPhysical release to allow replacement of a signal route (physical time out).
BallastGraded stone sub-base used for drainage and support of the track.
Ballast CleaningRemoval 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.
Ballast TrainA train of wagons to and from work sites conveying track ballast or any other equipment needed within a possession.
Bi-directional LineA line that is signalled to take trains in both directions.
BIMBuilding Information Modelling [aka Better Information Management]
Black BoxEquipment 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(...)
Block BellsThese 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
Block InstrumentAn 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.
Block JointAlso known as an insulated rail joint. A rail joint in which one rail is electrically insulated from an abutting rail.
Block SectionThe section of line between the section signal of one signalbox and the home signal of the next signalbox ahead
Block TokenA device carried by a driver as his authority to run over a single line worked by the Electric Token Block System.
Blocked LineA line / or a portion of line that is closed to the passage of trains
BobbyTraditional slang for a signaller (the original signallers were actually Railway Police Officers).
BogieA wheeled undercarriage pivoted below the end of a rail vehicle
BondA wire connection between the rails to ensure electrical continuity.
Bowmac“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
Box of EggsA portable device with lamps to test whether the conductor rail is still energised. This is also known as a Conductor Rail Test Lamp Set.
BSNBridge Strike Nominee - A person who has been certified as competent to implement the procedures for reopening lines after a bridge strike
CantrailStrip on the side coach above the window line where the body side meets the roof
CAPEOriginally 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.
Catch PitA 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
Catch PointsA 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(...)
CatenaryTerm given to overhead wires which support the contact wire on overhead line equipment
CESSThe 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.
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Chain / chA 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
CIRASCIRAS 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(...)
CISCustomer Information System - station information screens
Clamp LockA point operating mechanism, which locks the points by directly clamping the closed switch rail to the stock rail
Close CallAnything 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(...)
Cross Span WireA wire stretched across tracks holding the overhead line equipment in this desired position
CRTCritical 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.
Cyclic TopCyclic 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
DCDirect 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
De-icing TrainA special train fitted with equipment for clearing snow or ice from conductor rails
Deadman's Pedal/HandleSlang term for Driver’s Safety Device: device on traction rolling stock that will stop the train if the driver becomes incapacitated.
DEMICDerived from former telegraphic code indicating a failed train
DepotA complex of sidings, buildings, platforms, etc. where transhipment, stabling, servicing, repairs and other such activities are undertaken.
DerailmentA derailment is deemed to have occurred when the wheel flange has left the rail alignment and the wheel tyre has lifted from the railhead
Detonator protectionCarrying 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
Dets/DetonatorA 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(...)
DSDDriver’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
EASEngineering 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
Electrified LineA line which is electrified either by 25,000 volt AC overhead lines, or by 750 volt DC conductor rail.
ELREngineer’s Line Reference- a way to identify location/ structure on plans and directories
EmbankmentA 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.
EMCElectromagnetic 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.(...)
ESREmergency 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
Facing Point LockEquipment that physically locks points so that they cannot move
Facing PointsFacing 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(...)
FeatherSlang 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.
FFFFirst 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.
Fish Plate/fishplateSteel plate to secure the ends of two rails together (in jointed track).
FlaggingA system of signalling trains manually with flags during breakdown or suspension of the normal signalling system
Flank LockingFlank locking is a safety feature, incorporated in the signalling equipment, which then prevents signals operating on routes adjacent to other areas with a failure.
Flank ProtectionA 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.
FlatA 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.
Fouling PointThe point on a pair of converging tracks where the two trains would collide side on if allowed to approach together.
Four Aspect SignalA 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(...)
Four FootThe area between the inner running faces of a pair of rails.
FPLFacing Point Lock: a device to ensure that points which are facing the approaching trains are locked in position
Frangible
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.
GappedA 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(...)
GPLGround Position Light: a low-level shunting signal displaying lights rather than a disc.
Green CardCommon 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.
Green Zone workingAn 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.
Ground SignalA loose term for any signal set at ground level, typically shunting signals.
GSM-RGlobal System For Mobile Telecommunications for Railways.
GaugeThe distance between a pair of running rails. The standard gauge is 4 foot 8 ½ inches.
GUPATGive 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.
HABDHot 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.
Halt or Station HaltA railway station with minimal facilities where trains will usually stop only on request
Hand Pointspoints which are worked manually by an adjacent independent lever
Head Codeterm 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.
Headspan WireWire suspended across the tracks and from which the OLE is suspended.
Home SignalThe first stop signal on the approach to a signal box using the Absolute Block system of signalling
HookswitchA manually operated electrical isolation switch in conductor rail areas for local isolation.
Hookswitch PoleA wooden-handled pole used to operate a hookswitch.
Hot Axle Box DetectorSensor mounted on the outside of the rails of a track to detect the increased radiated heat emitted by a defective axle box or bearing.
Hot BoxAn overheated axle box. Usually the result of insufficient lubrication, or excessive speed
HS1HS1 – UK’s first High Speed (over 140mph) line, London – Essex – Kent – Channel Tunnel
IECCIntegrated 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
Impedence BondsAlso known as a “Spider”. Prevents traction current from entering the signalling system. Prevents traction current from entering the signalling system
In Advance OfAhead of, in the (normal) direction of travel.
In Rear ofBehind, in the (normal) direction of travel
IncidentAn unplanned, uncontrolled event which, under different circumstances, could have resulted in an accident
InfrastructureAny fixed assets or features of the operational railway which falls within the disciplines of civil engineering, signalling, telecommunications or electric traction power supply.
Inside of SignalStanding past, ie, inside the protection of that signal.
InterlockingInterlocking of points and signals, through the locking frame in the signal box, which prevents the accidental setting up of conflicting routes.
IntervalThe actual difference in time between trains
JNAPJoint 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(...)
Jointed TrackNormal rail in 60ft lengths, but can be 45ft or 30ft lengths
JuiceA slang term for electricity, especially traction current
Jumpera cable used for train control or term for a potential suicide
JunctionThe spot at which a branch diverges from the main line.
k
KGTA generic term to describe a road-rail vehicle.
LadderA layout of facing and trailing crossovers enabling movements across several parallel lines
Leaf FallApproximately five weeks in the autumn when leaves fall on the track requiring measures to assure adhesion.
Level CrossingA place where a railway and a road cross at the same level.
Lever FrameThis 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.
LFCLeaf 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.
Limit of ShuntA position on a railway track, usually marked by a notice of such, which represents the limit for any shunting movements
Line LightAn 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.
Line SpeedThe maximum speed at which traffic is allowed to run on a line.
London sideA term used to describe a specific point of a location, which is nearest to London
LookoutA 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.
LoopA line parallel to a running line, which by virtue of crossovers between the two lines, enables one train to pass or overtake another.
LOSLimit 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.
Main LineA railway route interconnecting locations of major importance.
Marker BoardDouble-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(...)
medscreenTo be ‘for cause’ screened for drugs and alcohol following a safety related incident
M&EEMechanical and Electrical Engineering (or Engineer)
Middle RoadTerm 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
Multiple unitA 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".
MVLCMedium Voltage Line Cover -Provides insulation for catenary, droppers and associated conductors against contact with trees, birds, wildlife or even vehicles and vandalism
MWLMiniature Warning lights - used on some footpath crossings
n
NCCFormerly the National Control Centre- now known as the NOC
NDANot 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.
Near MissA 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(...)
Nest of EggsA 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
Net OpsNetwork Operations- Network Rail department focussed on the operational and maintenance of the Railway
NROLNetwork Rail Online Logistics - the ordering and planning system for all railborne materials.
NROLNetwork Rail Online Logistics - the ordering and planning system for all railborne materials.
Neutral SectionAn arrangement of insulators in the OLE designed to ensure that two sections are kept electrically separate even during the passage of a pantograph
OSSOverspeed 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.
Out of CorrespondenceA term used when a set of points show neither a normal nor a reverse detection
OutageAn 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(...)
PaddleA 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.
PaladinPaladin Data Extract and Reporting System: a versatile train performance measurement facility producing analysis reports focusing on train performance and delay attribution
Pandrol ClipA clip used to hold in place the running rail to the sleeper
PanelAlso 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(...)
PantographA device fitted to the roof of an electric locomotive or EMU, which is sprung upwards to make electrical contact with overhead wires.
PathTerm 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(...)
PathwayA slot of time allocated for a train to travel along the railway
PCBPolychlorinated 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.
PeakMorning 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.
PEARSPaladin Data Extract and Reporting System: a versatile train performance measurement facility producing analysis reports focusing on train performance and delay attribution
Peg upSlang for giving a Line Clear to the box in the rear when working in Absolute Block regulations
PeriodA 28-day period, as defined by Network Rail.
PGIPlanned 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
pilotA 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(...)
Plain lineWhen 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.
PLODPatrolman’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
PnBPersonal or Physical Needs Break: a guaranteed break in a Driver’s turn of duty when free from duty.
Point BladesThe 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.
Point HeaterAn electric heater to melt snow and ice that might otherwise impede correct operation of points
Point MotorA single or double solenoid device attached to a turnout so that the points may be operated electrically from a remote location
PointsA 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(...)
Points Run ThroughA movement which runs through a trailing set of points which are not set in the correct position for the movement
POLRail Plant Operating Company in Possessions Licence
PONPeriodical Operating Notice: a bi-monthly publication, which contains all current amendments to the books of Rules and Regulations and certain miscellaneous notices.
PortalEntrance to a tunnel or a type of overhead line support
PossessionWhen 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(...)
PotA ceramic stand that supports the conductor rail in DC areas.
Power Operated PointsPoints operated by means other than mechanical (eg electric motor, hydraulics or compressed air).
PPSPossession Planning System - it manages the process for booking and recording of national engineering and access requirements (possessions, worksites, temporary speed restrictions).
PropellingMoving a train using a locomotive at its rear
ProtectionIn 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.
PTSPersonal 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
Pull Off signal-Operate signal to give a proceed or a less restrictive indication.
Push PullA 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.
PWayPermanent Way. The track of a railway line; the ballast, sleepers and rails.
q
Q TrainTrains 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).
Quadruple TrackA railway route in which two sets of tracks are provided for each direction of travel.
r
RARoute Availability or Right Away platform indicator
RA IndicatorA special signal to a train driver that a train is ready to depart from a station
RAIBRail 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.
RAIB Accredited AgentAn 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.
RAMRoute 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(...)
reactionary delayThe delay to trains resulting from an earlier train delay.
Red ZoneA site of work that is on or near the line, where the trains are still running
Red Zone WorkingA site of work if it is on or near the line and it has not been possible to set up a Green Zone
refugeA 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
RegionSince 2019 Network Rail is geographically split into 5 Regions
Scotlands Railway
Southern
Wales and Western
Eastern
North West and Central
regulateSignallers can regulate the train service by giving priority to one train over another.
RegulatorOfficer appointed by the Government to regulate the railway industry
relayAn 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
relief lineA secondary line which runs alongside a main line.
RETBRadio 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(...)
reversible lineA track on which traffic may be worked in either direction (bi directional)
Right of wayA term used for the signal given by a guard to a driver that he is permitted to depart
Right side failureA mode of failure, which causes a piece of equipment to cease functioning without compromising the safety of trains.
RIORail 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.
Rule BookA 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 of the routeRules agreed with train operators under which speed restrictions or temporary line closures can be imposed for maintenance purposes
run byUnauthorised passing of a signal at danger, or overshooting a station or designated stopping point.
run throughA 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 RailRunning surface of the rail. Can also apply to an interchange point between road and rail.
sanditeA mixture of sand and antifreeze, used for assisting traction adhesion during extreme weather. Sandite S4 also contains steel shot to assist track circuit operation
SATSSectioning 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(...)
SBI GaugeA loading gauge that permits operation of road-rail swap body vehicles
S and Cswitches and crossings the specially machined rails designed to permit trains to transfer between tracks.
Semaphore SignalsSignals 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
SentinelSentinel is the organisation set up to administer Track safety competence
Sequential LockingA refinement of ‘Interlocking’ that ensures signals are operated only in a certain order.
SETTOLSeasonal treatment on-Line. It’s a database that is used to manage the national seasonal infrastructure treatment plan
SFAIRPMeaning of So Far As Is Reasonably Practicable (SFAIRP): A guideline for rail organisations to assist them in developing a decision making framework
SHELTSafety, Health and Environmental Leadership Team
shoeTerm 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.
shuntThis is a short distance stock movement for the purpose of re-positioning, re-marshalling or berthing of trains.
SidingA 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.
SignalVisual 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(...)
signal boxThe control centre for signalling trains. This is where the signallers control the movements of trains by signals.
signal gantryA framework suspended across several train tracks, and upon which many signals may be mounted
SIMBIDSSimplified Bi-Directional Signalling: signalling provided to allow trains to run in the “wrong” direction during engineering work, line blockages, etc. without resorting to pilotmen
SISSStation information and security systems - customer information screens etc. (also partly known as CIS
six footCommonly used term to describe the space between two adjacent tracks
sleeperA 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
SLUStandard 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
SPADSignal Past at Danger.
There are various degree and type of SPADs catergorised A-D
specialA train that was not in the working timetable, and had been programmed via a special traffic notice
speed restrictionA 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(...)
SPTSignal 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.
SpurA 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
STESafety, Technical Engineering directorate within Network Rail- replaced with the Technical Authority (TA) in 2020
Stoneblower
A machine developed to maintain the trackbed.
StressingThe 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).
StructureA 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(...)
SubstationA building or compound containing electrical switchgear and equipment which supplies electricity to the conductor rails.
Swing Nose CrossingA 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.
switch railThe moving portion of rail on each side of a set of points.
SWLSafe Work Leader - person accountable for safe delivery of work within a worksite
SWMPSite 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(...)
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T and VTresspass & Vandalism. Now called Railway Crime
TAwithin the railway TA is Technical Authority- a directorate of Network Rail
TACTrain 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(...)
TamperA 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
TampingProcess that compacts ballast under sleepers to maintain the correct geometry of the track.
TASSTilt 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.
TCBTrack 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
Ten FootIdentifies the term given to the central space on a four-track railway (may actually be less than ten feet).
TerminusA 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
Theatre lightsDirectional lights found on approach to major stations
Third railA 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.
Three aspect signalA 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(...)
TOPSTotal 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
TOWSTrain Operating Warning System: gives audible warning to those working on the track of the approach of the train
TPATTake 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.
TPWSTwo 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(...)
Track CircuitAn 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(...)
TreadleElectrical switch operated by the train wheels, often for level crossing approach.
TRTSTrain 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
TrustTrain 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.
Trust DAThe delay attribution system for recording the size and reason for delays recorded by TRUST.
TSITechnical Specifications for Interoperability The development of Technical Specifications for Interoperability (TSIs) are the responsibility of the European Railway Agency (ERA).
TTCTwin Track Cantilever - a form of OLE structure with one post and carrying two sets of catenary from one cantilevered boom
TUPETransfer of Undertakings (Protection of Employment) Regulations 1981; legislation that protects earnings and conditions when employees transfer from one employer to another
TurnoutThe track configuration enabling trains to change from one track to another (widely called Points).
TVPTrack Visitors Permit- permit to allow temporary accompanied access to work site.
Two aspect signalA colour-light signal capable of displaying two aspects.
