VRIOGS 010.7 RevA - Public Transport Victoria
VRIOGS 010.7 RevA - Public Transport Victoria
VRIOGS 010.7 RevA - Public Transport Victoria
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<strong>Victoria</strong>n Rail Industry Operators Group Standards<strong>VRIOGS</strong> <strong>010.7</strong>TRACK BONDING, TRACK CIRCUITCONNECTIONS AND TRACTIONINTERFACESRevision:AIssue Date: 11/12/2008NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
ii<strong>VRIOGS</strong> <strong>010.7</strong> Revision A<strong>VRIOGS</strong> <strong>010.7</strong> TRACK BONDING, TRACK CIRCUIT CONNECTIONS ANDTRACTION INTERFACESRevision AIssue Date: 11/12/2008APPROVAL STATUSAPPROVER STATUS DATE QUALIFICATIONSDocument DeveloperVRIOG SteeringCommitteeApprovedAll SectionsAccredited Rail OperatorMetropolitan Train(Metro TrainsMelbourne)Intrastate Train(V/Line)Interstate Train(ARTC)Tram(Yarra Trams)For any queries please contact vriogs@transport.vic.gov.au.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision AiiiPURPOSE OF THE STANDARDThe Standard has been created through the collaboration of members of the<strong>Victoria</strong>n Rail Industry Operators’ Group (VRIOG) for the purpose of establishingstandards which, if implemented throughout the <strong>Victoria</strong>n Rail Network, will facilitatethe interoperability of infrastructure.The use of the Standard is not prescribed by law but, if adopted, conformity with theprovisions of the Standard is mandatory in order that the purpose of the Standard beachieved.DISCLAIMERThe Standard is published by the Director of <strong>Public</strong> <strong>Transport</strong> for informationpurposes only and does not amount to any kind of advice.Each person is responsible for making his or her own assessment of all suchinformation and for verifying such information. The content of this publication is not asubstitute for professional advice.The Director of <strong>Public</strong> <strong>Transport</strong> and VRIOG accept no liability for any loss ordamage to any person, howsoever caused, for information contained in thispublication, or any purported reliance thereon.COPYRIGHT STATEMENT© Director of <strong>Public</strong> <strong>Transport</strong> 2005.This publication is copyright. No part may be reproduced by any process except inaccordance with the provisions of the Copyright Act.Where information or material is so used, it should be used accurately and theStandard should be acknowledged as the source of the information.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
iv<strong>VRIOGS</strong> <strong>010.7</strong> Revision ATABLE OF CONTENTSSECTION 1.0 CONVENTIONS ...............................................................................1SECTION 2.0 DEFINITIONS...................................................................................2SECTION 3.0 SCOPE AND GENERAL ..................................................................43.1 Scope ...........................................................................................................43.2 Application....................................................................................................43.3 Background ..................................................................................................4SECTION 4.0 FURTHER DEFINITIONS.................................................................54.1 Electrified Tracks..........................................................................................54.2 Electrified Area .............................................................................................54.3 Non-Electrified Area .....................................................................................64.4 Immunised Areas .........................................................................................64.4.1 Transverse limit of Immunised Area .................................................74.4.2 Longitudinal limit of Immunised Area................................................74.4.3 Same Rail Corridor ...........................................................................74.4.4 Adjacent Rail Corridors.....................................................................7SECTION 5.0 NON-ELECTRIFIED TRACK AREAS...............................................95.1 General.........................................................................................................95.2 Extent of Provisions......................................................................................95.3 Electrified Tracks..........................................................................................95.4 Adjacent to electrified tracks ......................................................................105.5 Junctions with electrified tracks..................................................................105.6 Containment ...............................................................................................105.7 Track-circuited track ...................................................................................105.8 Non Track-circuited Track ..........................................................................115.9 Line Circuits................................................................................................11SECTION 6.0 ELECTRIFIED TRACK AREAS......................................................126.1 General.......................................................................................................126.2 Traction Supply Interfaces..........................................................................126.2.1 Substations.....................................................................................126.2.2 Tie Stations.....................................................................................136.2.3 Stray Currents (Conductive coupling).............................................136.2.4 Mains Harmonics (Inductive or Capacitive coupling)......................136.2.5 Traction System Ratings ..................................................................146.2.6 Current Capacity.............................................................................146.2.7 Touch Potential...............................................................................146.2.8 Flashover........................................................................................156.2.9 Cabling ...........................................................................................156.3 Track Circuit Bonding and Track Insulation................................................156.3.1 Single Rail.......................................................................................166.3.2 Double Rail .....................................................................................166.3.3 Bonding at Points and Crossings....................................................166.4 Cross (Tie-In) Bonding ...............................................................................176.4.1 Double Rail AC Track Circuits ........................................................186.4.2 Single Rail AC Track Circuits..........................................................186.4.3 Single Rail Impulse Track Circuits..................................................196.4.4 Double Rail Impulse Track Circuits.................................................196.4.5 Jointless Track Circuits...................................................................196.4.6 Tying-in Non-Track Circuited Tracks ..............................................196.5 Tram and Train Interfaces at Road Crossings (Tramway Squares) ...........206.6 Train Detection Equipment.........................................................................206.6.1 Axle Counters .................................................................................206.6.2 50Hz AC Track Circuits ..................................................................21NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision Av6.6.3 Double Rail .....................................................................................216.6.4 Single Rail.......................................................................................216.6.5 Audio Frequency Track Circuits......................................................226.6.6 Impulse Track Circuits ....................................................................226.7 Electrolysis Bonds ......................................................................................226.7.1 General...........................................................................................226.7.2 Location...........................................................................................236.7.3 Connection ......................................................................................236.8 Spark Gap Protective Devices....................................................................236.8.1 General ...........................................................................................236.8.2 Installation .......................................................................................236.9 Impedance Bonds ......................................................................................246.9.1 General ...........................................................................................246.9.2 Types ..............................................................................................256.9.3 Mounting .........................................................................................256.9.4 Connections ....................................................................................256.9.5 Side Leads ......................................................................................266.9.6 Neutral Point....................................................................................266.9.7 Reuse..............................................................................................276.10 Overhead Wiring Switches and Temporary Rail Connections....................276.11 Friction Buffer Stops and Bonding..............................................................276.12 Traction Overhead “Air Gaps” and placement in relation to signals ...........27SECTION 7.0 NON-ELECTRIFIED TRACK IN ELECTRIFIED AREA ..................287.1 General.......................................................................................................287.2 Train Detection ...........................................................................................287.3 Traction Current .........................................................................................287.3.1 Isolation...........................................................................................287.3.2 Overruns .........................................................................................287.3.3 Traction Run-Off .............................................................................297.3.4 Traction Fault Current ......................................................................297.3.5 Fault current path in Rails ................................................................297.3.6 Acceptable Levels............................................................................307.3.7 Calculation.......................................................................................317.4 Other Equipment ........................................................................................317.5 Immunisation ..............................................................................................317.6 Track Circuits .............................................................................................327.6.1 General...........................................................................................327.6.2 Single Rail Track Circuit .................................................................327.6.3 Double Rail Track Circuit................................................................327.6.4 Jointless Track Circuit.....................................................................327.7 Non Track Circuited Track..........................................................................327.8 Cross Bonding............................................................................................33SECTION 8.0 INSULATED RAIL JOINTS.............................................................348.1 General.......................................................................................................34SECTION 9.0 CABLES AND BUSBARS...............................................................369.1 General.......................................................................................................369.2 Electrolysis Bonding ...................................................................................369.3 Neutral Bus Bar ..........................................................................................369.4 Cables ........................................................................................................36SECTION 10.0 TRACK BONDING AND RAIL CONNECTIONS.........................4010.1 General.......................................................................................................4010.2 Installation ..................................................................................................4010.2.1 Labelling .........................................................................................4210.2.2 Connections ....................................................................................4210.3 Length of Track Leads................................................................................42NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
vi<strong>VRIOGS</strong> <strong>010.7</strong> Revision A10.4 Dual Gauge Track Bonding ........................................................................4310.5 Electrified Area ...........................................................................................4310.6 Non-Electrified areas..................................................................................4410.7 Reuse of Equipment...................................................................................4410.8 Commissioning Work..................................................................................45SECTION 11.0 LIST OF FIGURES .....................................................................51SECTION 12.0 LIST OF TABLES .......................................................................52SECTION 13.0 REFERENCES ...........................................................................53NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 1SECTION 1.0CONVENTIONS1) Words or phrases that appear capitalised out of context are defined within theDefinitions section of this VRIOG Standard.2) The word “Shall” is to be understood as mandatory.3) The word “Should” is to be understood as non-mandatory i.e. advisory orrecommended.4) Uncontrolled Standards may not be referenced within the VRIOG Standards.These include former PTC Standards, Franchisee Standards, FranchiseeSubcontractor Standards and Infrastructure Lessee Standards.5) Controlled Standards, including Australian Standards and other <strong>VRIOGS</strong>tandards, may be referenced but only if:• The referenced item can not be adequately explained with an amount oftext that could not reasonably be inserted into the body of the Standard.• The reader is not referenced to another Controlled Standard necessaryfor the item to be adequately explained i.e. one document link only.• The referenced document is a Figure or table and could not reasonablybe included in the appendices of the Standard.6) The format employed in the VRIOG Standards is compatible with AustralianStandards, and will be used from this point on.7) The numbering system for the VRIOG Standards is chronologically sequentialfrom the point of introduction, and is not based on any form of interpretivesystem.8) The VRIOG Standards contain engineering information necessary to operatea safe Railway. VRIOG Standards will not contain any information that can beconstrued as a work instruction, procedure, process or protocol. Thisinformation forms the basis of each individual entity’s Safety AccreditationCertification, and, as such, is outside the scope of VRIOG Standards.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
2 <strong>VRIOGS</strong> <strong>010.7</strong> Revision ASECTION 2.0DEFINITIONSTerminology used and / or applied in this Standard is defined as follows:TermAccredited RailOperator (ARO)ARTCBondingCWRCompetent PersonDesigner“Down” Track or“Down” DirectionElectrolysisElectrolysis Committeeof <strong>Victoria</strong> (ECV)Electrolysis ConnectionFlashoverIRJAccreditation VariationDescriptionA Rail Infrastructure Manager or Rolling Stock Operator whois accredited under Part 5 of the Rail Safety Act 2006.Australian Rail Track CorporationThe term used to define the connection and continuity ofpoints within a designed rail configuration/s; to ensurecontinuity of all designed rails for either track circuits toensure train detection is accomplished, or for the purpose oftraction return currents.Continuously Welded Rail.A person whose competency has been assessed by theARO or a recognised and accredited Authority as beingcompetent to perform the task.The legal entity undertaking the signalling design work in thisstandard.The direction or section of rail track that allows rail traffic totravel in a direction away from Flinders Street RailwayStation.Electrolysis is the leakage of stray Direct Current into theground, as an effect of the operation of both railway andtramway DC traction systems. This effect requires mitigationmeasures to prevent adverse effects and corrosion tosurrounding metallic infrastructure.The Electrolysis Committee of <strong>Victoria</strong> is the Industry Groupwho determines the actual locations of all necessary newelectrolysis connection points and also reviews all existingelectrolysis points and all electrolysis applications in <strong>Victoria</strong>with the ARO.Connection used as a common point for Electrolysispurposes.An electrical discharge over the surface of an insulator.Insulated Rail Joint and may be either of a mechanicalconstructed type or a GIRJ.Change to the accredited activities (including operational ortechnical standards) of the Accredited Rail Operator andTram Operators requiring approval by the Director, <strong>Public</strong><strong>Transport</strong> Safety <strong>Victoria</strong>.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 3TermPermit to WorkPTDPower Supply AuthoritySpark GapSignal EngineerSection HutsTouch PotentialTramway SquareTraction SystemEngineer“Up” Track or “Up”DirectionVRIOGDescriptionA permit issued by an Authority to allow work to beperformed under a set of controlled safety conditions.The <strong>Public</strong> <strong>Transport</strong> Division of the Department of<strong>Transport</strong>.The Authority that supplies electrical power to theInfrastructure.A protective device installed to all overhead tractionstructures to ensure a return path for dangerous faultcurrents, in the event of a breakdown of a 1500 volt DCoverhead traction insulator on the overhead tractionstructure.The person nominated by the ARO Infrastructure Manageror Others as the Engineer responsible for Signalling.Same definition as Tie Station.The voltage difference between an item (in the context ofthis standard it is the rail) and ground. Touch potential is thevoltage you would be exposed to if you were standing on theground and touched the item.The area of a intersection where both tram and rail vehicleshave passage and where all rails within the actual squareare electrically bonded together and are then isolated fromeither side of the actual square by means of insulated railjoints.The person nominated by the ARO Infrastructure Manageras qualified and responsible for the installation andmaintenance of the traction current supply and distributioninfrastructure as its representative for the works in hand.The direction or section of rail track that allows rail traffic totravel in a direction towards the Flinders Street RailwayStation.The <strong>Victoria</strong>n Rail Industry Operators’ Group comprising thefollowing members:• VicTrack• V/Line Passenger• Metro Trains Melbourne• Yarra Trams• Australian Rail Track Corporation (ARTC)• <strong>Public</strong> <strong>Transport</strong> Division of the Department of <strong>Transport</strong>(PTD)NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
4 <strong>VRIOGS</strong> <strong>010.7</strong> Revision ASECTION 3.0SCOPE AND GENERAL3.1 ScopeThis Standard deals with:1. Areas influenced by rail traction electrification at 1500 V DC potential from anoverhead line contact wire distribution system.2. Track bonding and track circuit connections in areas where traction areas areencountered.3. Track bonding and track circuit connections in areas where non traction areasare encountered.4. Track bonding and track circuit connections in areas where both traction andnon traction areas are encountered.5. Applications where immunization is required from Traction areas.6. Track circuit safety and reliability.7. Minimisation of electrical stress on impedance bonds and signallingequipment connected to the rail.8. Spark gap protective devices.9. Minimisation of touch potentials for the rail infrastructure subject to bothnormal operating and fault conditions.10. Electrolysis connection points and to minimise the effects of stray current andits consequent electrolysis corrosion.11. The various track bonding and track circuit cables and their applications.3.2 ApplicationThis Standard applies to all <strong>Victoria</strong>n Traction and Non Traction Rail areas and alsoapplies to those interfaces with ARTC as an Accredited Rail Operator (ARO).3.3 BackgroundThis Standard supersedes all other previous specifications on Track Bonding,Traction Interfaces and Track Connections within the Metropolitan and Regionalareas of <strong>Victoria</strong>.It also relates directly to ARTC Specification ESD-07-02 ARTC Track Bonding andSignalling Infrastructure in Electrified Areas.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 5SECTION 4.0FURTHER DEFINITIONS4.1 Electrified TracksElectrified tracks are defined as tracks where electric traction units are expected torun and where provision for traction current supply is maintained.The rails of electrified tracks shall be equipped to carry the traction return current forthe electric traction units. This shall include provision for the designed normalservice and peak traction return current on a continuous basis and also for themaximum potential fault currents.4.2 Electrified AreaThe electrified area is defined as the entire rail corridor under and between anyelectrified tracks and extending on each side to the nearer of either the rail corridorboundary or a line 15 m from the centreline of the electrified track nearest to theboundary, so long as that line is outside the envelope of all traction supply equipmentstructures for the electrified tracks.The extents of the electrified area are illustrated in Figure 1 and Figure 2.Figure 1 Transverse boundary of Electrified AreaAny non-electrified track that lies within the electrified area shall be considered aspotentially subject to a direct traction fault.The distance from an electrified track that may be considered as susceptible to directtraction faults may vary under different systems of electrification and differentAccredited Rail Organisations regimes.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
6 <strong>VRIOGS</strong> <strong>010.7</strong> Revision AFigure 2 Point of Separation and extent of Immunisation4.3 Non-Electrified AreaThe non-electrified area is defined as any part of the rail corridor outside theelectrified area.Where non-electrified tracks cross directly over or under electrified tracks they areconsidered to be on separate rail corridors. However, the section of the rail corridorimmediately above or below an electrified track is to be considered as an electrifiedarea.4.4 Immunised Areas1. The signalling infrastructure installed in the vicinity an electrified area issubject to a harsher environment than that installed on the non-electrifiedareas due to traction currents and the stray currents induced.2. The design of the signalling must consider the effects of operating in thisharsh environment in order to assure that a similar level of safety andreliability to that required anywhere on the Network has been achieved. Thearea within which additional precautions shall be taken is known as theImmunised Area.Note: Both electrified and non-electrified areas may be contained within theImmunised Area.3. Any electrical interference, which has entered the infrastructure within theelectrified area, will flow along any metallic conductor (track, pipe work,cables, bridge structures, etc) but the rail bed and ballast and ground alsoprovide paths for stray currents. This means that if an electrified track isclose to a non-electrified track there may also be interference effects even ifNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 7the two tracks are on different rights of way and even if the rights of waynever actually join. These effects can continue to follow the right of way for adistance well beyond the actual electrification infrastructure.4.4.1 Transverse limit of Immunised AreaFor the purpose of this specification the entire rail corridor under and between anyelectrified tracks and extending on each side to the rail corridor boundary isconsidered to be the Immunised Area.4.4.2 Longitudinal limit of Immunised AreaThe limit of the Immunised Area should be sufficiently remote from the effects of theelectric traction that non-immune signalling equipment can safely be installed. Thelimit of the Immunised Area therefore extends beyond the extent of the electrificationinfrastructure.1. Where the non-electrified track extends directly from the end of the electrifiedarea then a line perpendicular to all tracks at the last electrification supplystructure (mast, tension anchor, substation enclosure or end of traction supplyconductor) is considered the point of separation. Immunisation precautionsshould be implemented for a distance of at least 3000 m from the point ofseparation.2. Where non-electrified track diverges laterally from an electrified rail corridorthe point of separation is taken as being a line at right angles to the centrelineof the non-electrified track from the point where its structure gauge is clear ofthe boundary of the electrified area. Immunisation precautions should beimplemented for a distance of at least 3000 m from the point of separation.4.4.3 Same Rail CorridorWhere an electrified track shares a common rail corridor with a non-electrified trackbut the electrification terminates whilst the non-electrified track continues then allimmunisation precautions should be implemented on all infrastructure within theelectrified area and for a distance of at least 3000 m from the point of separation.4.4.4 Adjacent Rail Corridors1. Where an electrified track runs adjacent to a non-electrified track even wherethis is on a physically isolated right of way, immunisation precautions shouldbe considered whenever the centrelines of the two tracks come within 100 mand should definitely be implemented if the two centrelines come within 30 m.2. In this instance the point of separation shall be the taken as the point 15 mfrom the centreline of the electrified track along the shortest straight linebetween electrified and non-electrified tracks. The remaining distance alongthis straight line shall count towards calculating the required extent ofimmunisation provision.3. Where the separate rail corridors cross above / below one another thecrossing is considered to be an electrified area on the non-electrified track.The points of separation shall be lines at right angles to the centreline of thenon-electrified track 15 m from where the centrelines of the tracks cross.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
8 <strong>VRIOGS</strong> <strong>010.7</strong> Revision AFigure 3 Immunisation of Adjacent Rail CorridorNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 9SECTION 5.0NON-ELECTRIFIED TRACK AREAS5.1 GeneralWhere non-electrified tracks run in the vicinity of electrified tracks, the extent of theinfrastructure provision needs to be determined. Within this area three situationsexist.1. Electrified Tracks: tracks are electrified to allow electric trains to run from theelectrified area to some point on or connected to the non-electrified track andmust provide a return path for the electric traction current which is acceptablefor the normal operation of electric trains.2. Non-Electrified Tracks in Electrified Area: tracks that are non-electrifiedbut electric traction faults may inject fault current into the non-electrified railsand a return path for the electric traction current.3. Tracks in Immunised Area outside Electrified Area: tracks that are nonelectrifiedand subject only to the effect of stray currents coupled into thetracks or line-side circuits from the traction current circuit.5.2 Extent of ProvisionsGenerally signalling infrastructure within an electrified area and for some distancebeyond must be immunised from the effects of the electrification.1. Where non-electrified rails are used by electric trains (example being overpoints and crossings), provision for normal traction current return must bemade. In such cases the design of the rail bonding shall be based on makingthe impedance of the return path as low as practical to minimise tractionsupply losses, overheating of equipment and voltage build-up along the railsboth from the DC and harmonic components of the return current.2. Where the non-electrified rails are not used by electric trains, provision fornormal traction current return is of no advantage to non-electrified lines;therefore it is preferable that provision for traction fault current only be made.In this case the design of the rail bonding shall be based on making theimpedance of the fault current path such that voltage build-up does not reacha harmful level for either the equipment or any personnel in contact with therails.5.3 Electrified Tracks1. Wherever electric trains may run over non-electrified tracks the infrastructureshall make full provision for traction current and in accordance with thisspecification; including traction current bonding of the rails and immunisationof all signalling equipment against both traction return and stray currents.2. Where the electric traction supply system terminates whilst the rail corridorcontinues the full provision for traction current shall extend at least oneelectric train length beyond the last point at which an electric train tractioncollector could make contact with the supply system.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
10 <strong>VRIOGS</strong> <strong>010.7</strong> Revision A5.4 Adjacent to electrified tracksWhere non-electrified tracks are in an electrified area they should not carry normaltraction currents.1. The design of the rail bonding should therefore not allow for traction returncurrent to flow through the non-electrified rails. Any bonding design whilstadhering to the normal signalling principles for track circuit series continuityshould provide only a single path between any rail and the traction returncurrent system.2. In the event of an incident such as overhead line damage or misrouting of atrain the bonding components of the non-electrified tracks could be subject totraction current return. The bonding infrastructure shall ensure that anytraction current does not lead to an unsafe situation for personnel on thetrack.5.5 Junctions with electrified tracks1. If non-electrified track runs in an electrified area there may be situationswhere electrified track has either a running connection to or across the nonelectrifiedtrack. This connection may itself be electrified to allow electrictrains to access other tracks beyond the non-electrified line or to allow forelectric trains to be misrouted and then recovered without damaging theelectrification infrastructure.2. Full traction return capability for the non-electrified line shall be provided tothe extent that an electric traction unit could travel whilst still drawing powerfrom the electrified line.5.6 ContainmentWhere the electric traction supply system terminates whilst the track continuesmeasures shall be made to ensure that the return traction current is contained withinthe electrified area. The first provision shall be an insulated rail joint in each rail inthe vicinity of the end of the electrification supply infrastructure. These joints shall benominally 15 m from any rail of an electrified track normally coinciding with the firsttrack circuit joint beyond the point of separation.5.7 Track-circuited trackThe spread of stray traction return current using the rails should be constrained ifpossible; therefore at approximately 1200 m from the point of separation a trackcircuit joint will be inserted with an IRJ in each rail.This location should be chosen to coincide with both the layout of the signallinginfrastructure and any physical features of the geography (e.g. watercourses,tunnels) that may act to contain or exacerbate stray currents.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 115.8 Non Track-circuited TrackWhere electrified track joins a non track-circuited line; IRJs shall be inserted in eachrail of the non track-circuited track nominally 15 m from the electrified track. The nontrack-circuited rails shall be bonded together and to the nearest traction return rail orimpedance bond neutral point. If the non track-circuited track diverges from theelectrified area, then a second set of IRJs shall be installed at approximately 1200 mfrom the point of separation with the rails on the side nearer the electrified area againbonded together.5.9 Line CircuitsTo contain the effects of stray current in lineside circuits it is recommended that anyconductive cable route, trunking, galvanised pipe should also be provided withgalvanic isolation at or close to the location of the “1200 m” IRJs.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
12 <strong>VRIOGS</strong> <strong>010.7</strong> Revision ASECTION 6.0ELECTRIFIED TRACK AREAS6.1 GeneralAny traction current supply infrastructure installed on electrified track where electrictrains are intended to run shall be designed and maintained to the standards of theelectrical supply infrastructure owner for the benefit of whom the equipment isinstalled.The calculation of traction return resistance is the responsibility of the TractionSystem Engineer; however, the Signal Engineer should be aware that the followingguidelines exist.Number of electrifiedtracksOne trackTwo tracksMultiple tracksNumber of rails required for traction current return2 rails at all times (with exception over points and crossinglayouts)4 rails except for short distances, within interlockings, overpoints where 3 may be acceptableMaintain the ratio for dual track unless specific permission isobtained from the Infrastructure Manager.Table 1 Rails required for traction return currentLong single-rail track circuits should not be used in electrified areas.Where the use of single rail track circuits over long distances is unavoidable the casemust be referred to the Infrastructure Manager for specific approval, as highertraction return resistances adversely affect DC traction current Circuit Breaker(DCCB) settings.6.2 Traction Supply InterfacesThe traction return current rails shall be interfaced with the Traction System NegativeBus bars at each Substation and Tie Station.6.2.1 Substations1. At each substation the connection from the negative busbar to each trackused for traction current return shall be duplicated.2. Cables carrying the traction return current to the negative busbar shall bespecified to carry the full rated traction load i.e. 2000 A per rail.3. Where there is more than one track used for traction current return, they shallbe tied together except where the traction system has provided a separatenegative busbar for each track.4. Where single rail track circuited or non-track circuited track is in use thetraction current return rails shall be bonded directly to the negative bus bar. ItNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 13is preferable that single rail track circuits not be used for these connectionsunless adjacent siding or refuge tracks provide supporting parallel paths.5. Where double rail track circuits (including jointless track circuits) are in usethe connection to the rails shall utilise two impedance bonds of theappropriate rating (i.e. 2 x 2000 A/rail impedance bonds ) with one connectionto the negative busbar attached to the neutral point of each impedance bond.6. Where the connection to the substation is made at double rail 50 Hz trackcircuits, the impedance bonds at substations shall be located on either side ofan IRJ, as the track circuit will not support two impedance bonds located midtrack circuit. The adjacent bond neutral points shall be bonded together withcables or busbar in the usual manner.7. Where jointless track circuits are in use the connection shall made at midtrack, if possible, but at a minimum of 50 m from any track circuit tuning unitconnection. Impedance bonds in these situations shall be resonated asrequired. Where the connection cannot be made 50 m from the junction oftwo jointless track circuits they be treated as conventional double rail trackcircuits and shall require IRJs in each rail, impedance bonds and connectionto the substation negative busbar from the neutral point of the bonds.8. High voltage impulse track circuits are generally not suited to the connectionof additional impedance bonds in mid-track. Connections to Substations shallbe made across the junction of two track circuits specifically sited for thatpurpose.9. Where impedance bond and cables are connected to substations, tie stations,or negative return pillars there shall be a “Danger High Voltage SubstationCables –Access Permit Required” sign affixed in a permanent manner to theimpedance bond that has the connections to the substation or tie station.10. Traction return cables from impedance bonds to substations or tie stationsshall be by connection to the Junction Box -Plan No. STD G0066.11. All cables shall be in accordance with the <strong>VRIOGS</strong> Signalling CableSpecifications.6.2.2 Tie StationsAt each Tie Station the connection from the negative busbar of the Tie Station toeach track shall be similar to that of a substation, with exception that only two cableconnections per track are required and cables are to be aluminium 95 mm 2 .6.2.3 Stray Currents (Conductive coupling)Substations in electrified areas tend to have extensive earth grids. When tractionfaults occur, these earth grids may be subject to considerable earth voltage rise.Where signalling equipment is installed in the vicinity of a traction substation caremust be taken with the installation of any earthing electrodes to avoid the possibilityof applying such earth potential rises to the internal signalling equipment circuitry.6.2.4 Mains Harmonics (Inductive or Capacitive coupling)In DC electric traction areas it should not be assumed that the interfering currents willbe only DC. Not only does multi-phase rectification of mains supply frequencyintroduce harmonics of the mains frequency but modern train motor control circuitsNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
14 <strong>VRIOGS</strong> <strong>010.7</strong> Revision Ause higher frequency chopping of the DC supply to manage the train speed. Thesechopping frequencies again generate harmonics which may be directly transmitted tothe rails and via stray currents into lineside equipment and cable born circuits.6.2.5 Traction System Ratings1. Where traction current normally flows in the rails the rail bonding and anyequipment connected to the track has to be designed to take account of boththe voltage and current effects.2. For 1500 V DC traction the following are the general levels to be considered.a. The DC resistance values of individual rails to be used to calculatetraction return resistance are as follows:Rail SectionResistance / 1000 m60 kg/m 0.0330 ΏTable 2 Resistance of standard rail sectionb. Normal traction equipment rating of 2000 A per rail continuouscapacity.c. DCCB settings 3000 A to 8000 A depending on the current loadingrequired by train operation.d. Spacing between substations or tie stations is 2.0 to 4.0 km.e. Standardised designs consider the 6 and 10 minute rating ofequipment for the typical gradients and traffic patterns within thesection.6.2.6 Current Capacity1. All equipment attached to the rails shall be designed to withstand the currentsand voltages associated with the electric traction current. For series elementsthe standing traction current shall be taken as the current due to themaximum number of trains within the section between adjacent substationsdrawing normal running current with at least one train on each track drawingmaximum starting current. This figure may need to be increased if there ismore than one station platform between adjacent substations.2. Heat rise calculations shall include an analysis of the worst-case period oftraffic throughout the day. The design must ensure that the operatingtemperature of the traction return equipment remains within the manufacturersspecified limits given the heat rise and cool down characteristics of theequipment for the worst case segment of the timetable.6.2.7 Touch PotentialFor new power systems works, the Designer must ensure that the maximum touchpotentials at accessible locations for the following events do not exceed the valuesas identified in Table 3:(a) Normal train operations (at headway interval); andNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 15(b) A direct traction fault to the rail.time (s) Potential (V)0.02 9400.05 7700.1 6600.2 5350.3 4800.4 4350.5 3950.6 3100.7 2700.8 2400.9 2001.0 170≤ 300 150> 300 120Table 3 –Touch Potential Limits6.2.8 FlashoverThe Designer shall ensure that, where a “flashover” to rail occurs due to faultyvehicle or overhead insulator, sufficient current is conducted for sufficient time to tripthe required sub-station circuit breakers. This feature should not be lost through asingle-point.6.2.9 Cabling1. The bonding cables and cable connections are the part of the traction currentreturn path most vulnerable to damage or vandalism. Consequently thedesign of all traction bonding connections shall allow for at least one parallelcable or connection to become disconnected. In this circumstance theremaining cables or connections shall still allow the normal designed returntraction current to flow without causing further damage.2. A minimum of two cables or connectors each rated for the full normal currentor three cables or connectors each rated for half the normal current shall beinstalled.6.3 Track Circuit Bonding and Track InsulationWhere track circuits are installed, GIRJs and bonding shall be provided as necessaryto ensure that track circuits operate effectively, traction return path is maintained, andtrain detection is maintained over all parts of the track circuit whilst broken railNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
16 <strong>VRIOGS</strong> <strong>010.7</strong> Revision Aprotection is maintained to the extent required by <strong>VRIOGS</strong> 012.1 Standard forSignalling Design and Documentation.6.3.1 Single Rail1. The signalling rail of single rail track circuits shall be bonded to the samestandards as the traction rail with exception of series bonds, which shall not beused or rated for traction return current.2. Transpositions, where insulated joints and bonding are provided to swap thetraction rail of a single rail track circuit between the Up and Down rails of onetrack circuit, or between contiguous track circuits, are not permitted exceptsubject to prior specific individual approval by the Infrastructure Manager.Where a traction transposition is installed, the number and size of cables shallbe the same as are used for impedance bond neutral connections in the samearea.6.3.2 Double Rail1. Double rail track circuits use both rails for traction return and it is important toensure that traction is balanced for the correct operation of impedance bondsand rack circuits.2. For the purpose of improving broken rail detection in double rail track circuitsit is preferable to use additional receivers rather than full parallel bonding overpoints and crossing layouts.3. Rails connected by full parallel bonding shall not exceed 50 metres in lengthand the track circuit parameters shall be specifically checked to conform theycomply with the manufacturer’s recommendations.4. All parallel bonds shall be at least duplicated at each connection point.6.3.3 Bonding at Points and Crossings1. On main lines, bonding of points shall be arranged to provide maximumbroken rail detection of both rails in the main line and maximum assurance oftrain detection in the turnout. Series bonding is the bonding method that is tobe utilised and refer to Plan STD_G0061 Track Circuit Series BondingArrangement.2. On double rail track circuits this shall be achieved preferably by the use ofseparate receivers on each leg of the turnout.3. Where this is not practicable, special parallel bonding arrangements for theturnout leg of the track circuit shall be applied.4. On single rail track circuits, series/parallel bonding shall be used over pointsin preference to full parallel bonding, subject to the requirement that sufficientrails be available for traction current return.5. Where the preferred methods are not practicable, for instance in crossoversbetween main line tracks, double rail track circuits with full parallel bondingover points may be used with the approval of the Infrastructure Manager.6. Insulation of points and crossings shall be arranged to place insulated jointsin the less-used path as far as possible.7. Bonding shall be arranged to minimise, as far as practicable, the length of allparallel and series bonds.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 178. Track insulation should be designed to use the minimum number of insulatedjoints needed to comply with all other requirements.9. In complex areas track insulation should be designed using large-scaledrawings of the actual point and crossing work. Even with careful designsuch drawings may fail to accurately reflect the relative positions of items ontrack; consequently complex bonding layouts which appear feasible on papermay be unmanageable in the field and should be avoided.10. Designs using complex, multi-branched track circuits are not acceptable - anytrack circuit which branches three or more ways shall be subdivided into twoor more simpler track circuits.11. For bonding at ‘V’, ‘K’ and all points crossings, rail bonds should always betwo (2) rail head bonds; and welded to the outer head of the running rails inaccordance to Plan STD_G0097 Cross Bonding Typical Arrangement-Electrified Area, Plan STD G00154 Track Circuit Bonding at Points andCrossings, Plan STD G0153 Typical Arrangements of Bonding at Points andCrossings and Plan MS97/0730 Arrangement of Bonds for Tangential Points.6.4 Cross (Tie-In) Bonding1. Cross bonding between track circuits on adjacent tracks is used to distributethe traction return current over the maximum number of available conductors(rails) thus reducing the resistance between the train and the substationbusbar and reducing touch potentials. Note: due to the design or switching ofthe feed circuits; traction return current from trains on each side of a crossbond location may flow, to either the nearer or the more remote substation.2. Cross bonds shall be as short as possible and tie-in points shall be as near aspracticable directly opposite each other on parallel tracks.3. In open track areas, tracks shall be tied-in at substations and sectioning huts,with cross bonds as per Table 4 and Table 5.4. Cross bonding between substations and tie stations is normally designed tocarry one third to one half of the traction return current generated on one trackto the parallel track(s). In fault conditions the cross bonding may have to carrythe full traction load.5. Cross bonds should be placed close to stations where trains stop inpreference to mid section.6. The dimensions of cable, type of cable to be used and the methods ofconnection and installation are detailed in Section 9.0.7. Tie in and similar type bonding cables from tracks to either tie or substationsmust be installed as under track crossings and in accordance to <strong>VRIOGS</strong>012.2 Specification for Signalling Supply, Construction and Installation.8. The following tables identify where it is recommended that cross bonds beinstalled.a. Between any two substations separated by less than 5.0 km, theaverage and maximum distances between cross bond locationsdepends on the minimum main line rail type and must not exceed thevalues given in the following table:NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
18 <strong>VRIOGS</strong> <strong>010.7</strong> Revision AMinimum main-linerail weightAverage distancebetween cross-bondlocations (betweensubstations)Maximum distancebetween any two crossbond locations47 kg/m 1600 m 1900 m53 kg/m 1800 m 2100 m60 kg/m 2000 m 2400 mTable 4 Distance between cross bonds where substations are less than 5.0 km apartb. Between any two substations separated by more than 5.0 km, theaverage and maximum distances between cross bond locations mustnot exceed the values given in the following table:Minimum main-linerail weightAverage distancebetween cross-bondlocations (betweensubstations)Maximum distancebetween any two crossbond locations47 kg/m 1300 m 1500 m53 kg/m 1500 m 1800 m60 kg/m 1600 m 1900 mTable 5 Distance between cross bonds where substations are greater than 5.0 kmapart6.4.1 Double Rail AC Track Circuits1. There shall be no more than one cross bond connection in any track circuit.2. Where IRJs are in use, the cross bond is made between the neutral points ofthe impedance bonds at the end of the track circuits. In some cases wherethe type of track circuit permits it, an additional impedance bond can be fittedmid track circuit for the purpose of tying-in to a parallel track.6.4.2 Single Rail AC Track Circuits1. Single rail track circuits provide a reduced rail cross section for the returntraction current path, with consequent increased traction return resistance.2. Parallel traction rails shall be bonded together by appropriately rated tractioncables, to form a common traction return ‘grid’. Cross bonding may alsoinclude connections to sidings or impedance bond neutral points on adjacentdouble-rail track circuits.3. A minimum of one cross-bond location must be located in any single-rail trackcircuit region.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 194. Where the length of the single-rail track circuit region exceeds 200 m, crossbondsmust be placed at either end; provided that no more than one end ofany double-rail track circuit is cross-bonded.5. Single rail track circuits shall be limited to areas covered by points andcrossings.6.4.3 Single Rail Impulse Track Circuits1. Single rail impulse track circuits provide a similar restriction to the tractioncurrent return path as for single rail AC track circuits.2. Cross bonds shall be provided at intervals not exceeding 250 m.3. Single rail track circuits shall be limited to areas covered by points andcrossings.6.4.4 Double Rail Impulse Track Circuits1. On double rail impulse track circuits the cross bonding shall be made atintervals of between 800 m - 1600 m, with 800 m being the optimum distanceand with one clear track circuit between the “tie-in” bonds.6.4.5 Jointless Track Circuits1. Cross bonds shall be provided at 800 m – 1600 m intervals with 800 m beingthe optimum and rated according to the traction current rating of the section.Jointless track circuits require an impedance bond to be providedapproximately at the middle of the track circuit for cross bonding connections.2. The actual cross bonding is connected between the neutral points ofimpedance bonds installed on parallel tracks. Impedance bonds used for“tying-in” shall be rated for the traction rating of the area where they areinstalled.3. The air core inductor in the tuned loop on CSEE track circuits shall not underany circumstances be used for “tying-in”, connection of spark gaps orelectrolysis connection points.6.4.6 Tying-in Non-Track Circuited Tracks1. Where tracks are wired for electric traction but not track circuited, both railsshould be bonded directly together and tied in to the traction return system attheir extremities and at intermediate points, depending on the length of thetrack involved.2. Non-track circuited electrified track shall be cross bonded to track circuitedelectrified track at locations appropriate to the types of track circuit installed.3. Bonding shall be installed in accordance to Plan STD_G0097 Suburban AreaCross Bonding Typical Arrangement.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
20 <strong>VRIOGS</strong> <strong>010.7</strong> Revision A6.5 Tram and Train Interfaces at Road Crossings (Tramway Squares)1. Where tram and train lines interface (tramway square areas) there must bebonding at and around the square for both the 1500 volts DC traction fortrains and the 600 V DC power for trams.2. All rails of the actual tramway square for either tram or train are electricallybonded together utilising 300 mm 2 aluminium flexible cables and 35 mm 2head of rail bonding.3. The outer extremities of the tramway square are physically isolated by theuse of IRJs joints in all rails.4. The negative return cables either side of the tramway square are routed to aNegative Return Cable Connection Box and then to a heavy duty electricalswitch that is manually or electrically controlled and operated, for the passageof either a train (1500 V) or tram (600 V) to ensure the correct voltage isavailable for the passage of either the tram or train and in the correctsequence. The cables from the switch are then connected to the actualtramway square for the return of negative traction power for tram and train.5. The actual position of the negative return switch is both controlled andindicated to an identified and controlled location or area. The negative returnswitch is such that a clean break between tram and train position during theoperation of the switch must be achieved.6.6 Train Detection Equipment1. Train detection using the same rails as those carrying the traction returncurrent requires that interference from the traction current should not allow aloss of detection. Since the current carrying rails need to provide acontinuous path to the substation return busbar the usual signalling practiceof using IRJs must be reconsidered.2. Track circuits used in conjunction with electric traction must provide anunbroken, low-resistance path for traction current to flow from train tosubstation, while the maintaining the sectioning of tracks to provide a meansof determining the location of a train.3. All track circuits within the electrified area shall be DC immune.4. Axle counters do not depend on continuous rail, therefore no breaks in thetraction current return conductor need occur. Indeed it is possible to bondadditional conductors in parallel with the rails if necessary.6.6.1 Axle CountersWhere axle counter equipment has been type approved for use within DC electrifiedareas the installation design usually requires local earthing of the trackside boxes.Care must be taken to ensure that no dangerous voltage potential can build upbetween the parts electrically connected to the rails and those connected to the localearth. Where axle counters are utilised with no other form of train detection, crossbonding shall be in accordance with this specification and the same as for non trackcircuited areas.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 216.6.2 50Hz AC Track CircuitsIt has been established that this type of track circuit is sensitive to interference bystray mains frequency currents, resulting in potentially unsafe situations. Specialmaintenance precautions are required to ensure safe operation of existinginstallations, and no new tracks of this type shall be installed except in the case ofminor changes in the midst of an existing installation.6.6.3 Double Rail1. In a double rail AC track circuit impedance bonds permit the DC tractionreturn current to flow in both rails whilst preventing the actual track circuitfeed from flowing from rail to rail. Impedance bonds rely for their properoperation on traction currents remaining balanced between the rails of thetrack circuit. It is the responsibility of the Signal Engineer to ensure that thetraction return path is properly balanced.2. The impedance of these bonds on double rail AC track circuits becomes alimiting factor in setting the length of the track circuit and the maximumshunt value at which the relay will drop.3. Older style bonds have an impedance of 0.3 to 0.4 ohms at 50 Hz that limitsthe maximum shunt characteristic to 0.15 - 0.2 ohms.4. A resonated bond may have an impedance approaching 2.5 ohms at 50 Hz.6.6.4 Single Rail1. The design of single rail 50 Hz track circuits shall include arrangements tolimit the maximum level of DC traction current which may be applied to thetrack relay.2. The design of single rail 50 Hz track circuits shall include arrangements tolimit the maximum level of DC traction current which may be applied to thetrack relay.3. Track circuit length shall be limited such that the longitudinal DC voltagedrop under maximum traction conditions does not exceed 20 V. Typicalmaximum single rail AC track circuit lengths are 200 m. However this lengthmay need to be reduced in certain cases. Typical values for DC voltagedrop are set out in Table 6.Traction Current (A)1700 3400 5200 6800Track Circuit Length (m) Voltage Drop (volts) (For 60kg rail)50 2.81 5.61 8.58 11.2275 4.21 8.42 12.87 16.83150 8.42 16.83 25.74 33.66200 11.22 22.44 34.32 44.88250 14.03 23.05 42.90 56.10300 16.83 33.66 51.48 67.32Shaded values exceed permitted maximum of 20 volts.Table 6 D.C. Voltage drop across Track Relay on Single Rail TrackNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
22 <strong>VRIOGS</strong> <strong>010.7</strong> Revision A4. Similar values shall be calculated for individual track circuits and used toverify that the measures provided to protect the relay and / or feed units aresufficient.5. Where the length of track circuit is excessive, the levels of DC beingsuperimposed may result in failure of the relay-protecting fuse. The designshall provide sufficient series resistance in the relay circuit to limit DCtraction current to a level that will ensure continuous operation of the trackcircuit equipment. A minimum DC loop resistance of 1 ohm is required in therelay circuit.6.6.5 Audio Frequency Track Circuits1. Jointless track circuits are normally separated by means other than IRJs.2. Jointless track circuits are suitable for use in traction areas as there are notraction sensitive components.3. Traction current unbalances between rails are normalised at tying-in points,and by air-cored inductors in some CSEE jointless track circuits.4. The maximum length of audio frequency jointless track circuits is not limitedby traction current but by the net effect of shunt resistance across the track,including the effects of any impedance bonds used for tying in or connectionto substations and sectioning huts.5. In some circumstances, audio frequency track circuits may be installed asconventional track circuits commonly separated by IRJs and withimpedance bonds to provide traction return continuity usually where a sharpcut off is required or when interfacing with another type of track circuit.Traction return and bonding requirements for this arrangement are the sameas for conventional double rail track circuits.6.6.6 Impulse Track CircuitsSingle rail impulse track circuits develop a higher voltage impulse than their doublerail counterpart and are therefore slightly more effective in obtaining a shunt underpoor conditions. The traction return rail of a single rail impulse track circuit may beconnected to the neutral point of any type approved impedance bond in an adjacenttrack.High voltage impulse track circuits shall be used particularly over points andcrossings, and infrequently used tracks where it is most important to guarantee asafe and effective shunting of the track circuit.6.7 Electrolysis Bonds6.7.1 GeneralThe traction current return system shall include the connection of electrolysis bondsas required.1. The Infrastructure Manager in consultation with the Electrolysis Committee of<strong>Victoria</strong> (ECV) shall determine the actual location at which electrolysisbonding facilities are required. The type of bonds to be used together with theNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 23bond conductance and expected maximum operating voltage and current shallbe calculated by the Traction System Engineer.2. The Signal Engineer is responsible for the connection of the electrolysisbonds to rail at the specified locations and all work shall be undertaken to hissatisfaction.6.7.2 LocationElectrolysis bond connections shall be made to a convenient traction current returnconductor close to the Power Supply Authority’s electrolysis bond. The electrolysisbond should not be more than 50 m from the rail connection. Suitable connectionpoints are:1. Existing impedance bond neutral point connections,2. The traction rail of any single rail track circuit and3. Either rail of a non-track circuited track used for normal traction currentreturn.6.7.3 ConnectionFor double rail track circuits the impedance bond shall be connected in accordancewith this specification.Connection to a single rail track circuit shall be in accordance with this specification.6.8 Spark Gap Protective Devices6.8.1 GeneralSpark Gap Protective Devices must be provided to all structures supporting orattached in any manner to the overhead traction supply. They are there to protectagainst electric shock in the event of an insulator failing and rendering the structure“live” at traction voltage. The spark gap is connected to the steel overhead structureat approximately 1500 mm above rail level via a hole drilled into the overheadstructure and then assembled in accordance to "Spark Gap Earthing Device" PlanNo. STD_G0070.6.8.2 InstallationThe spark gap device shall be installed as per the following;1. The Constructor shall provide the spark gap device and install the cable toconnect from the spark gap to the rail, which shall only be connected to thetraction return rail to the satisfaction of the Signal Engineer.2. Should spark gaps be required at locations where they are necessary to beinstalled on concrete; or other than steel structures, such as a concrete bridgepier supporting an over rail bridge where the electrical traction lines areconnected to fittings on the underside of the bridge the following should becomplied to. In these circumstances the Traction System Engineer shallsupply and install a PVC sheathed cable from the overhead insulator to theNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
24 <strong>VRIOGS</strong> <strong>010.7</strong> Revision Aspark gap device connection point on the overhead structure. The Constructorshall then provide the spark gap device and install the cable to connect fromthe spark gap to the rail, which shall be connected to the traction return rail tothe satisfaction of the Signal Engineer.3. An approved crimp lug shall be fitted to the spark gap cable and connection ofthe cable made to the rail and also to the spark gap.4. Where overhead structures are installed or relocated, the Constructor shallsupply and install a spark gap and cable for each structure. Each spark gapshall be connected to the traction return rail by a 95 mm 2 aluminium singlecore cable in accordance with <strong>VRIOGS</strong> Signalling Cable Specification.5. Spark gap cables and connections are only to be made to the traction returnrail. The spark gap cable shall be laid on ballast level to the verge of the trackformation; and then installed in either rigid orange PVC electrical conduit orheavy duty flexible orange PVC electrical tube, and buried at a minimumdepth of 300mm to the connection point at the overhead structure. All cablesshall be fastened to sleepers as per within this specification6. On single rail track circuits the spark gap shall be connected to the tractionreturn rail.7. On double rail track circuits the spark gap shall be connected to the rail that isclosest to the actual overhead structure being protected by the fitment of thespark gap-except that when audio frequency track circuits are in use and theconnections of subsequent overhead structures must remain on the same rail,and change to the opposite rail at the middle of the track circuit.8. Spark gaps shall not be installed within the tuned loop area of a frequencytype track circuit.9. Connection to the rail shall be in accordance with this specification.10. Cable lugs shall be provided at both ends of the spark gap cable. Lugs shallbe bi-metallic or copper and comply with AS4325.1, e.g. CABAC PartNo. CAL95-12 or approved equivalent. Thick walled glue lined heat shrink(100 mm in length) shall be used to seal where the cable enters the lug.11. The spark gaps shall be supplied in accordance with the "Spark Gap EarthingDevice" Plan No. STD_G0070.12. Where train stabling security gates are in close proximity to steel structuressupporting overhead wiring, consideration must be given to the possiblerequirement for a spark gap protective device and in accordance with EN50122-1:1998 Railway Applications-Fixed Installations-Part 1:ProtectiveProvisions relating to Electrical Safety and Earthing.6.9 Impedance Bonds6.9.1 GeneralThe Constructor shall supply and install all necessary impedance bonds including thereplacement of any existing impedance bonds.1. Negative return traction cabling shall not be installed within the same conduitor cable route as other signal cabling and shall be separated from all othercabling in accordance with <strong>VRIOGS</strong> 012.2 Signal Supply Construct InstallSpecification.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 252. Traction return bonding cables shall be 300 mm 2 flexible aluminium cablessupplied in accordance with the <strong>VRIOGS</strong> and the Infrastructure Manager’sSignalling Cable Specifications.6.9.2 TypesThe Constructor shall supply and install WRSA 2000 type series impedance bondswhich are rated at 2000A continuous per side or 4000 A continuous in total, or anInfrastructure Manager’s type approved equivalent. (This includes the WRSA 2000Rtype resonated bonds for 50 Hz and 25 Hz, 2000AF for audio frequency and 2000HVfor Jeumont Schneider high voltage type track circuits.)6.9.3 Mounting1. Impedance bonds shall be installed on steel frames mounted outside thetrack and not between rails. Impedance bonds on contiguous track circuitsshould be mounted on a common frame.2. Impedance bonds are to be mounted in a vertical plane. The Constructor is tosupply and install approved mounting frames and foundations.3. Impedance bonds when installed in an upright position shall have a protectiveweatherproofing cap installed on top of the impedance bond, to protectagainst the ingress of water.6.9.4 Connections1. The connections of cables to impedance bonds i.e. side leads, neutral leadsand tie-in bond leads shall be with crimped cable lugs specified in thisspecification.2. Where the type of impedance bond does not permit direct connection of thenominated cables suitable tinned copper adapter plates shall be provided topermit correct termination of the nominated cables and lugs.3. Side, neutral and tie-in lead terminations shall be accessible for examinationand disconnection with the impedance bond lid or cover in place but shall notbe unduly exposed to damage. Cables shall be mechanically supported toreduce any load on the termination point and cable lugs.4. No impedance bond cable connection shall be less than 600 mm aboveground level.5. Bonding connections to the rail shall be in accordance with this specification.6. Where impedance bond and cables are connected to substations, tie stations,or negative return pillars there shall be a “Danger High Voltage SubstationCables –Access Permit Required” sign affixed in a permanent manner to theimpedance bond that has the connections to the substation or tie station.7. Traction return cables from impedance bonds to substations or tie stationsshall be by connection to the Junction Box -Plan No. STD_G0066.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
26 <strong>VRIOGS</strong> <strong>010.7</strong> Revision A6.9.5 Side Leads1. There shall be a minimum of two side leads from the impedance bond to eachrail. The track bonding plans specify the number of side leads required inparticular situations.2. Side lead connections to rail shall be made as close as practical to theinsulated joint. Where the insulated joint has been ‘Thermit’ welded in place,the side leads shall be connected between the joint and the weld.3. Impedance bond cables are to be identified at the point of rail connection andon the impedance bond connection; in accordance with this specification.4. To minimise traction return system resistance, all side leads should be keptas short as possible, while maintaining a tidy and safe installation.5. To avoid unreliable operation of the impedance bond due to traction currentimbalance, all side leads on any individual impedance bond shall be of equalDC resistance. Generally, making all leads of equal length will satisfy thisrequirement. Where impedance bonds are mounted off track, the upper orfarther side lead shall be connected to the near rail and the lower or nearerside lead shall be connected to the far rail. To facilitate the use of equal sidelead lengths, side lead rail connections shall be to the inside face of each railand the upper side leads on vertical frame-mounted impedance bonds shouldbe terminated to the bond from above. Where welded head-bond connectionsare used, these shall be connected to the outside of the rail.6.9.6 Neutral Point1. The neutral connections between adjacent impedance bonds shall preferablyconsist of a tinned copper busbar as specified in this specification. Thisbusbar should also be used for terminating any cables for tie-in bonds orconnections to substation or sectioning hut busbars.2. Where the copper bus connection is not practical, such as with mid trackmounted impedance bonds, there shall be a minimum of four neutral leadsbetween the impedance bonds.3. Cables between impedance bond neutral points shall be kept as short andstraight as possible.4. Where the impedance bond is used to change from a single rail to a double railtrack circuit, the total number of neutral leads specified shall be connected tothe common (traction) rail of the single rail track circuit.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 276.9.7 Reuse1. Where re-use of existing impedance bonds is specified or has beenauthorised by the Infrastructure Manager, the impedance bonds are to betested to ensure they are within Infrastructure Manager’s specifications, andall bonding cables shall be supplied and installed by the Constructor.2. The Constructor shall re-cable to <strong>VRIOGS</strong> Standards any existing impedancebonds which are to be retained in service, and also those that are not installedto current Specifications, or are not fit for service.6.10 Overhead Wiring Switches and Temporary Rail ConnectionsRail connections for overhead wiring switches and temporary overhead wiringconnections such as is used for “earthing protection” when Permits To Work onoverhead wiring are issued, shall only be made to rails connected to the tractionreturn system.These are:• Traction rails of single rail track circuits.• And for areas where both rails of a track circuit /section are used fortraction return, the closest rail to the overhead switch shall be utilised forthe connection, so as to minimise cabling and exposure of damage to thecable.6.11 Friction Buffer Stops and BondingFriction Buffer Stops rely on being clamped to the rails to achieve their frictionalsliding characteristics. Where friction buffer stops are provided on track circuitedlines, insulated rail joints are to be provided before the buffer stops to ensure thecorrect operation of the track circuit. Bonding shall be provided to ensure that therails the buffer stop is mounted on are connected to the traction return system.6.12 Traction Overhead “Air Gaps” and placement in relation to signalsOn electrified lines, signals that display a stop aspect must be located sufficiently farfrom an air gap to ensure that a train is not brought to rest with its pantograph in theair gap section.Air gaps and Sectioning Switches must not be located within 100 metres on theapproach side of signals.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
28 <strong>VRIOGS</strong> <strong>010.7</strong> Revision ASECTION 7.0NON-ELECTRIFIED TRACK IN ELECTRIFIEDAREA7.1 GeneralEven in electrified areas electric trains will not normally run over non-electrified areasof infrastructure.The additional risks due to the presence of the electric traction infrastructure can beclearly defined as:1. Electrical interference with signalling equipment due to conductive couplingfrom traction return current.2. Electrical interference with signalling equipment due to conductive couplingfrom traction fault current.3. Electrical interference with signalling equipment due to inductive or capacitivecoupling from traction harmonics.7.2 Train DetectionAny track subject to the provision of full traction return bonding shall be treated as anelectrified track as far as the requirements for track circuit traction bonding, crossbonding, and immunisation of equipment is concerned.7.3 Traction CurrentElectrical interference with signalling equipment from traction return current shouldbe minimised by ensuring that the tracks do not provide a through path for tractioncurrent to flow from one point in the electrified network to another.7.3.1 IsolationIsolation of traction current described in section 7.2 above shall be provided by theinsertion of an IRJ in each rail that abuts the rails of the electrified track. Whereelectric trains cannot inadvertently run across these IRJs (as at a diamond crossing)then only a traction supply equipment fault should lead to the track carrying tractionreturn current.7.3.2 Overruns1. Where it is possible that an electric train could be inadvertently routed ontoa non-electrified track then the train itself could bridge the protecting IRJsand inject traction return current into the rails.2. In such instances the non-electrified track for a distance at least the lengthof a normal electric train shall be provided with full traction bonding forInterstate Lines being 3000 m and for all other areas being 1200 m.(Directly related to the length of trains operating over the Network.)NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 297.3.3 Traction Run-OffIf the traction current supply infrastructure provides for supply conductor run-offs atconnections to non-electrified tracks then the tracks on which an electric train couldstill make contact with the supply conductor shall be considered as electrified tracksand the containment and overrun provisions outlined above shall be applied.7.3.4 Traction Fault Current1. Where non-electrified tracks run in an electrified area it is considered that afault to the traction supply infrastructure, or to a train on the electrified tracks,could result in the full traction supply potential being connected directly to therails.2. Any signalling equipment connected to the rails shall therefore be designed towithstand possible 1500 V DC traction faults. These fault currents couldinclude stray currents with rectifier and train traction equipment harmonics aswell as traction earth faults on trains. The injected current may produce bothhigh voltages direct to the running rails and high circulating currentscontaining a number of harmonic frequencies.3. It can be assumed that these faults will be transitory in nature (circuit breakerresponse time) but potentially of very high current (DCCB setting). To ensurethe rapid operation of the DCCB it is necessary for the rails of the nonelectrifiedtracks to be bonded together and, via an acceptably low impedancepath, to the traction return busbar.7.3.5 Fault current path in RailsTo ensure that normal traction return current does not flow in this path the designmust provide for a single ended path from each section of non-electrified track.Reference is made to ARTC Specification ESD-07-02 ARTC Track Bonding andSignalling Infrastructure in Electrified Areas; and the following Figure 4.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
30 <strong>VRIOGS</strong> <strong>010.7</strong> Revision AFigure 4 Bonding for Traction Current Return and Fault ProtectionBecause of the single ended nature of this path a traction fault at the extremity will bethe worst-case design situation. Under this circumstance not only must the DCCBtrip out but also the voltage rise in the rail relative to the surrounding s must beconstrained within an acceptable level.7.3.6 Acceptable Levels1. The acceptable voltage level at the rail is determined by the hazard suchvoltage implies. For most signalling equipment suitable surge arrestors orsimilar should be used on electrified tracks to cope with any expectedvoltage surge.2. The more relevant hazard however is to personnel who may be in contactwith the rails when a fault occurs. As these tracks will be considered nonelectrifiedit is unlikely that work methods will require the rails to bespecifically earthed and it may be expected that individual rails or bondingcables may be disconnected during work procedures without taking apossession of the adjacent electrification infrastructure.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 313. Under these circumstances the bonding design should still maintain a safevoltage level Vmax the value of which may depend on the possible durationof the surge. ARTC Standard PDS 10 – ‘Safe Limits of DC Voltages’ detailsthe factors which determine this level; the Traction System Engineer shouldprovide details of the DCCB time to cut off the fault current.7.3.7 Calculation1. Each section of fault current return should be calculated individually basedon the DCCB settings for the location. Based on the values in ARTCStandard PDS 10 with DCCB ranging from 2000 A to 8000 A and DCresistance of rail from 0.04 Ω/km to 0.033 Ω/km this gives a fault touchpotential voltage Vr of 100 V along a single rail at a distance ranging from312 m to 1.5 km from the negative busbar.2. The spacing between substations is generally about 3 km thus any spurshould be divided at the mid point giving a length of about 1.5 km andhence a maximum Vr at the end of the spur of 100 V to 500 V depending onthe current setting of the DCCB.3. The latter figure is above what may be considered acceptable based onCurve A within ARTC Standard PDS 10. Curve A indicates a maximumvoltage for ‘Long Term Threshold of Let-Go’ at 160 V. By placing a rail torail bond at the end of the spur (for double rail track circuits use animpedance bond without the neutral point connected) both rails would carrythe fault current thus halving the resistance of the spur and hence Vr to250 V. This figure may be considered acceptable for the duration of theDCCB operation.4. If the calculated rail voltage Vr is still considered unacceptable then thelength of the spur shall be subdivided into two or more shorter spurs byinserting IRJs as required.7.4 Other EquipmentAny cables to track connected equipment, including point machines and signal lampunits, should have no metallic shield or armour which could conduct fault current intothe equipment housings.7.5 Immunisation1. All signalling equipment within an Immunised Area shall be designed andconstructed with a suitable level of immunity to the potentially interferingcurrents produced by the electric traction system.2. Due to the high voltages and currents associated with electric tractionsupplies large circulating currents and earth return currents can be expected.These may couple to any conductive circuit within the signalling installation ormay be conducted to the equipment frames via the earthing systems installedfor personnel touch voltage and surge protection.3. Reference for information and treatment for immunization purposes referenceshould also be made to EN 50121-4:2006 Railway Applications-Electromagnetic Compatibility-Part 4: Emission and Immunity of the SignallingNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
32 <strong>VRIOGS</strong> <strong>010.7</strong> Revision Aand Communications Apparatus; EN 50122-1:1998 Railway Applications-Fixed Installations-Part 1:Protective Provisions relating to Electrical Safetyand Earthing and also EN 50122-2:1999 Railway Applications-FixedInstallations-Part 2: Protective Provisions against the effects of stray currentsby D.C Traction Systems.7.6 Track Circuits7.6.1 GeneralTrack circuit and Axle Counter equipment installed within the electrified area shall bydefinition be within the Immunised Area as per this specification, as far as theacceptable equipment and design is concerned. Rail bonding within the nonelectrifiedarea shall be carried out to the standards of electrified tracks except thatthere will be no requirement for cross bonding other than for the single connectionfrom each spur to the traction return current system.The following additional guidelines should be considered.7.6.2 Single Rail Track Circuit1. Keep the common rail as far as possible on the side nearest the electrifiedtracks.2. Where only one single rail track circuit is required it may be treated as adouble rail track circuit for fault current purposes.3. A single impedance bond may then connect both rails to the traction currentreturn system.7.6.3 Double Rail Track CircuitSince impedance bonds in series around a pair of IRJs constitute an unnecessarycost for non-electrified tracks, minimise the number of tracks in series if possible.7.6.4 Jointless Track Circuit1. Impedance bonds may only be installed in every other track circuit; thereforethe length of jointless track circuited areas may easily become excessive.2. IRJs shall be inserted in each rail at a minimum of one location between eachpair of substations or tie station to avoid providing a path for return tractioncurrent when one substation is taken out of circuit.7.7 Non Track Circuited Track1. Non Track Circuited track should be bonded for traction current return in asimilar manner to track circuited track.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 332. Both rails of non track circuited track should be bonded together with tractionbonding cable at both extremities of the track and at the cross bond tie totraction return system if that is not at an extremity.3. Non track circuited track shall be treated as with jointless track circuits in theprovision of IRJs between substations.7.8 Cross BondingNon-electrified lines within the electrified area should generally be connected to thecross bonds at each substation and tie station to ensure the best path to trip theDCCB in the event of a traction fault.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
34 <strong>VRIOGS</strong> <strong>010.7</strong> Revision ASECTION 8.0INSULATED RAIL JOINTS8.1 General1. Glued Insulated Rail Joints (GIRJ) are the preferred option for all insulatedjoint installations.2. The Contractor shall supply and install all new glued insulated rail joints(GIRJs) in running lines which shall be of the encapsulated glued type inaccordance with Plan No. 2095/93.Prior to commissioning works; the requirednew glued insulated rail joints are to be installed with the InfrastructureManager’s approval, and all temporary cables for bonding purposes of theglued insulated joints shall be in accordance with this specification.3. Temporary “jumpering out” of new and “yet to be commissioned into service”insulated rail joints shall be:• In non-electrified areas by use of two bonding cables of 6mm 2 copperwelding cables connected to the rail either side of the IRJ by anapproved bolted type connection. Cables are to be affixed to thesleepers by steel saddles and galvanised nails or an approvedalternative method to prevent the cables being laid over the rail.• In electrified areas by use of two bonding cables of 300mm 2aluminium cables connected to the rail either side of the IRJ by anapproved bolted type connection. Cables are to be affixed to thesleepers by steel saddles and galvanised nails or an approvedalternative method to prevent the cables being laid over the rail.4. On commissioning, all existing GIRJs requiring removal shall be suitablymarked and fitted with two temporary “jumper” type bonds by the Constructor.• In non-electrified areas these bonds shall be constructed of twoapproved 16 mm 2 insulated copper welding type wires, fixed to theweb of the rail by an approved bolted type connector and copper lugs.Cables are to be affixed to the sleepers by steel saddles andgalvanised nails or an approved alternative method to prevent thecables being laid over the rail.• In electric traction areas, these bonds shall be constructed of twoaluminium bonding cables 300 mm 2 fixed to the web of the rail by anapproved bolted type connector and bi-metallic or aluminium lugs.Cables are to be affixed to the sleepers by steel saddles andgalvanised nails or an approved alternative method to prevent thecables being laid over the rail.5. Each GIRJ requiring removal shall be indicated by the words "IRJ OUT"painted in yellow paint on the sleeper adjacent to the GIRJ. An arrow shallalso be painted on the sleeper pointing to the GIRJ to be removed.6. GIRJs shall be removed by the Constructor as soon as practicable followingcommissioning of the relevant stage and replaced by continuously welded rail(CWR) in accordance with the Infrastructure Manager’s track maintenanceinstructions.7. Under NO circumstances shall GIRJ’s be marked or painted directly.8. GIRJ’s within points and crossings shall be installed in the least used or theslower speed route where ever possible.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 359. Track insulated joints shall be positioned so that no vehicle can be foul of apoint layout without the points track circuit being occupied.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
36 <strong>VRIOGS</strong> <strong>010.7</strong> Revision ASECTION 9.0CABLES AND BUSBARS9.1 General1. Cables are used to connect impedance bonds and negative bus bars to railand between neutral points of impedance bonds. They are also used for tie-inbonds, cross bonds, bonding of mechanical rail joints, “out of service” IRJs,and the connection of electrolysis bonds to rail.2. Bus bars should be used between neutral points of adjacent impedancebonds when they are mounted externally to the track.3. Crimp lugs are used to terminate bonding cables for connecting to impedancebonds, neutral busbars and rails.4. The current rating of cables and busbars shall be matched to the definedtraction current rating of the installation area.5. Specified crimp lugs are designed to carry the full traction rating.6. The cables to be used in various applications are set out below. Trackinsulation and bonding plans may augment these minimum standards inparticular circumstances.9.2 Electrolysis BondingOne 95 mm 2 aluminium cable shall be provided and connected from the identifiedelectrolysis connection point to the traction current return conductor via theimpedance bond neutral point.9.3 Neutral Bus BarWhere the impedance bonds are mounted on stands next to the track, the connectionbetween adjacent impedance bond neutral points should be made using a tinnedcopper bus of 3500A continuous rating to AS3000 Table C or by the use of 4 number300 mm 2 aluminium bonding cables.9.4 CablesAll cables utilised shall be compliant to <strong>VRIOGS</strong> Signal Cable Specifications or to theInfrastructure Manager’s Specifications.See below Table 7 for cable types and applications.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 37ApplicationCable Type 300mm 2alum95mm 2alum16mm 2copper16 mm 2twistedflexiblecopper6 mm 2copperand inlinejointed toweldingcable6 mm 2copperweldingcableRailhead Railheadand point and pointlayout layoutcopper copperbraided braidedbond bond6 mm 2 35 mm 2Impedance Bond Side leads 2 - - - - - - -Impedance Bond Neutral toImpedance Bond NeutralConnection point leadsImpedance Bond Neutralconnection point to a Tractionsingle rail connection pointImpedance Bond Tie-In bondleadsImpedance Bond - Cross BondsleadsNegative Return TerminationBox to Neutral to substationnegative bus connectionImpedance Bond Neutral Pointto Negative Return ConnectionBoxImpedance Bond Neutral toNegative Return ConnectionPoint in Tie StationTraction Bonding at Tram RailInterfaces-Tramway Square toeach line of tram and rail to andfrom negative return switchMechanical joint bonding -Electrified areas4 - - - - - - -4 - - - - - - -2 - - - - - - -2 - - - - - - -8 - - - - - - -4 - - - - - - -- 2 - - - - - -4 - - - - - - -- - - - - - - 2Mechanical joint Bonding- Nonelectrifiedareas- - - - - 2 - -NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
38 <strong>VRIOGS</strong> <strong>010.7</strong> Revision AApplicationCable Type 300mm 2Bonding out IRJ or GIRJ inElectrified areasalum95mm 2alum16mm 2copper16 mm 2twistedflexiblecopper6 mm 2copperand inlinejointed toweldingcable6 mm 2copperweldingcableRailhead Railheadand point and pointlayout layoutcopper copperbraided braidedbond bond6 mm 2 35 mm 22 - - - - - - -Bonding out IRJ or GIRJ in Nonelectrifiedareas- - - - - 2 - -Spark Gap Device - 1 - - - - - -Electrolysis Bond - 1 - - - - - -Rail Head BondElectrified areasRail Head BondNon-electrified areasPoint Layout BondElectrified areasPoint Layout BondNon-electrified areasJointless Track Circuit TrackLeads- set of 2 leadsAC, High Voltage Impulse trackcircuit track leads –set of leadsin Electrified areas- - - - - - - 2- - - - - - 2 -- - - - - - - 2- - - - - - 2 -- 1 - - - - -- - - - 1 - - -AC, DC, Westrack, JeumontSchneider HV track circuit trackleads –set of leads in NonelectrifiedareasAC, High Voltage Impulse trackcircuit Signal bonding crossjumpers in Electrified Area- - 2 - - - - -- - - - - 2 - -AC, High Voltage Impulse trackcircuit Traction bonding crossjumpers in Electrified Area2 - - - - - - -NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 39ApplicationCable Type 300mm 2AC, DC, Westrack, High VoltageImpulse track circuit signalbonding cross jumpers in NonelectrifiedAreaalum95mm 2alum16mm 2copper16 mm 2twistedflexiblecopper6 mm 2copperand inlinejointed toweldingcable6 mm 2copperweldingcableRailhead Railheadand point and pointlayout layoutcopper copperbraided braidedbond bond6 mm 2 35 mm 2- - - - - 2 - -GCP and HXP track connectioncable- set of leads- - - 2 - - - -GCP and HXP track End ofShunt cable- - 2 - - - - -Electronic coded DC TrackCircuit Track Leads- set of 2leadsAudio Frequency Overlay TrackCircuit Track Leads- set of 2leads- - - 2 - - - -- - - 2 - - - -Table 7 Use of Cable for Traction Bonding and Track Circuit ConnectionsNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
40 <strong>VRIOGS</strong> <strong>010.7</strong> Revision ASECTION 10.0TRACK BONDING AND RAILCONNECTIONS10.1 GeneralRail connections and track circuits as specified in this section shall include alltrackside units, earthing, boxes, mounting posts, foundations, impedance bonds,insulated rail joints, associated track connections, cabling, terminating shunts,coupling units, and signal and traction head and cross bonding, electrolysisconnections, spark gap units and cabling and traction feeder cable to the substationnegative pillar for existing trackwork and any new or altered trackwork.10.2 Installation1. Temporary bonding of insulated joints shall be installed where necessary forstagework, and cabling installed in accordance with this specification2. The Constructor shall supply and install all necessary Jointless Track Circuitscomplete (i.e. UM71 type, or other Infrastructure Manager’s type approvedequivalent).3. Where Jointless Track Circuits are installed the Constructor shall ensurethere are no other connections to the track within the “tuned loop” area ofother cabling such as spark gaps or electrolysis cabling.4. High Voltage Impulse track circuits (i.e. Jeumont Schneider or otherInfrastructure Manager’s approved equivalent) shall be supplied and installedfor single rail track circuit applications and in accordance with <strong>VRIOGS</strong> 012.1Signal Design Specifications.5. The Constructor shall supply and install all necessary conduits, cables andtrack connection fittings and install the track circuits in accordance with thisspecification within the limit of works and as shown on the signallingarrangement plan.6. The track circuit transmitters, receivers, relays and power supplies shall bemounted in field locations cases supplied and installed by the Constructor.7. The trackside field matching units, tuning units, air core inductors, etc are tobe installed by the Constructor in accordance with the manufacturer’sinstallation manuals, or as accepted by the Infrastructure Manager. Theheight above rail to the uppermost section of all items listed within this clauseis to be 800mm approx.8. All new track circuits and in service track circuits shall have all trackconnections and track circuits adjusted to the Infrastructure Manager’sspecifications and carried out by a competent person.9. All cabling to the track rail web is to be fixed to timber bearers by means ofheavy duty galvanised steel saddles (full style) and galvanised nails. Saddlesare to be staggered on each individual cable and are not to be in contact witheach other when affixing parallel track cables. This is especially so atJointless Type Track cabling areas.10. On concrete bearers an approved cable fastening device and plate; shall beaffixed in four positions equally spaced along the sides of the concrete bearer,NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 41with a suitable adhesive and cables fastened within this plate.11. The Constructor shall supply and install all track circuit and traction bondingcables in accordance with the <strong>VRIOGS</strong> and the Infrastructure Manager’sSignalling Cable Specifications.12. Track wires and track connection points are to be accessible at all times andnot covered by paths, access tracks or road, pedestrian walkways, etc. Allcables are to be kept clear of access pathways during installation and uponfinal construction.13. Where level crossing predictors are used, the track wires shall be inaccordance with Figure 9- Typical HXP and GCP Track Circuit Connections.The Combined Transmitter/Receiver track wire length shall not exceed152 metres. Transmitter track wires shall not exceed 60 metres. Fifty percentand one hundred per cent points are to be identified and marked on a metalplate attached to a track sleeper or timber (refer to plan STD G0049 PointTrackside Labelling for Control Number and “N&R” Labels to Indicate Lay ofPoints).14. All cables are to have heavy duty or thick wall glue lined heat shrink tubingapplied over cable ends where they are connected to lugs and links so thatthe heat shrink extends over the lug stem and over the cable to prevent theingress of water. Heat shrink length is approximately 100 mm.15. Track wires from different track circuits are to be routed independently fromthe track connection to the nearest pit, trunking or housing enclosure toprevent any means of incorrect identification and/or connection to theincorrect track circuit.16. All signalling cross bonding jumper cables are to be kept to a minimum lengthand are to be connected to the rail web on the nearest side of the rail from thedirection of the incoming cable.17. Bonding for track continuity shall be by means of rail head bonding utilisingtwo flexible copper bonds welded to the rail head.18. All in-line cable joints shall be staggered. The in-line joint is to be enclosed inheavy duty glued heat shrinkable tubing.19. In-line cable joints shall have both conductors of each cable crossing overeach other within the jointing link and the ends of each conductor protrudingfrom the end of the jointing crimp link. The link shall be crimped in fourpositions along the length of the link.20. All track circuit leads and signal cross bond jumpers are to be enclosed inorange Heavy Duty flexible PVC tubing for their complete length.21. Where shunts or coupling capacitors are installed they are to be located tothe nearest timber or concrete bearer ; and have a galvanised three (3) mmsteel cover plate installed by an approved method to the bearer , such that itcovers the entire exposed area of the coupler or capacitor and that is fixed tothe bearer.22. All signal and traction head of rail bonds are to be installed by the electricbrazing method or to an alternative method as approved by the InfrastructureManager.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
42 <strong>VRIOGS</strong> <strong>010.7</strong> Revision A10.2.1 Labelling1. All track wires, impedance bond connections are to be labelled with astainless steel or similar robust labels suitably permanently stamped orengraved with the cable designation as identified on the Bonding Plan,example. 123T. RB. Steel labels are to be fixed to the cables with black heavyduty cable ties as close as possible to the point of connection to the rail orconnection at the impedance bond.10.2.2 Connections1. The method of connection of all track circuit leads to rails shall be by anapproved bolted rail type connections fastened to the rail in accordance to thisspecification.2. All holes drilled into the centre of the rail web for the purpose of connection oftrack cabling shall to be placed as close as is practical to the insulated railjoint (IRJ). This is dependant on rail size and the type of insulated rail jointassembly; and nominally 800mm from the actual separation point of theinsulated rail joint assembly is the location for the closest hole, with all othernecessary holes drilled from that point and at a minimum of 125mm apart andmaximum 250mm, so as not to interfere with the integrity of the rail.3. All rail connections or bonds between rails and equipment shall be madeutilising a Infrastructure Manager’s approved; bolted type connector:• 6mm diameter for all cable connections of 4 mm 2 , 10 mm 2 and 16 mm 2 .• 12mm diameter for all cable connections of 25 mm 2 to 400 mm 2 .4. All crimp links and lugs shall be appropriate to the application, example.Aluminium on aluminium cables, copper on copper cables and bi-metallic forjoining aluminium to copper.5. All jointing and connection of lugs is to be completed by crimp devices thatuse the compression method of crimping and not the indent method.10.3 Length of Track Leads1. Where AC, DC, Westrack and Jeumont Schneider type track circuits areinstalled, consideration should be given to not exceeding maximum tracklead resistance values.2. Where long length track leads are encountered the size cable should becarefully selected to cater to the track circuit characteristics andmanufacturer’s recommendations.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 4310.4 Dual Gauge Track Bonding1. Traction type bonding for common rails and non-common rails; on dual gaugetrack layouts shall be by a pin brazing or similar Infrastructure Managerapproved method, utilising two 35 mm 2 copper type bonds for eachconnection.2. NON Traction type bonding for common rails and non-common rails; on dualgauge track layouts shall be by a pin brazing or similar Infrastructure Managerapproved method, utilising two 6 mm 2 copper type bonds for each connection.3. Track leads at the feed end of the track circuit shall be arranged such that theactual track connections are to the common rail and to the outer rail. (toensure integrity of the bonding between the non common broad and standardgauge rails)4. Track leads at the relay end of the track circuit shall be arranged such that theactual track connections are to the common rail and to inner rail (to ensureintegrity of the bonding between the non common broad and standard gaugerails).5. Bonding wires/cables between the two outer rails shall be connected fromouter rail web to outer rail web and of a length such that they are only longenough to cater to being flexible for rail expansion and yet not long enough tobe damaged by track machinery.6. Bonding for non-common rails; on dual gauge track layouts shall be inaccordance with this specification or an approved Infrastructure Managermethod, and spaced at:• No greater than 15 m intervals where points and crossing areas areencountered;• No greater than 100 m where straight track areas are encountered and witha minimum of four bonded locations per track circuit.10.5 Electrified Area1. Connections to rail shall be installed using the following method;• The rail web shall be drilled with a No. 19 drill (7/8" diameter) and holesize checked with the GO/NO GO gauge.• Immediately the hole has been drilled, the copper bush shall be insertedwith the flange on the side of the rail to which the connection shall bemade.• The bush shall then be expanded by means of the special hydraulic toolwhich draws a conical headed plunger through the bush causing the bushto be expanded and extruded to form a permanent contact with the rail.• A hollow healed hexagon bolt shall be inserted through the bush so thatthe threaded portion projects from the bush flanged side. The stud headsurrounds the projecting part of the bush without touching it.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
44 <strong>VRIOGS</strong> <strong>010.7</strong> Revision A• Lugs shall then be crimped onto the cross bond or track cable. Thickwalledglue lined heat shrink shall be used to waterproof the joint. Thecable lug is fastened to the rail by means of the hexagon bolt with flatwasher and nut.2. Wherever possible track wires shall be connected directly into the impedancebond in preference to being connected to the track.3. Track wires for AC, DC or Jeumont type track circuits are to be in-line cablejointed to track lead cable, copper Hypalon cable 6 mm 2 to <strong>VRIOGS</strong> and theInfrastructure Manager’s Signalling Cable Specifications. The track lead cableis to be approximately 2 m long and the correct colour track lead is used tosignify the polarity of the track connection.4. Track wires for JTC and CSEE type track circuits are to be aluminium cable95 mm 2 , flexible to the <strong>VRIOGS</strong> Signalling Cable Specifications.5. All signalling cross bonding jumpers shall be installed with 6 mm 2 copperHypalon cable coloured red or black depending on the polarity of the rail leg.(Note: there always two bonding jumper cables installed for this purpose).6. Bonding of rail joints for track circuit continuity shall be by means of head ofrail bonding utilising two (2) 35 mm 2 flexible copper bonds per rail joint andwelded to the rail head.7. Traction return cross bonding shall be installed in accordance with planSTD_G0097 Bonding Typical Arrangement.10.6 Non-Electrified areasTrack cables, bonding and connections in the non-electrified area shall be:1. For AC, DC, WESTRAK and HVI track circuits, connection to the rail shall bevia Pot Head type Installation and be in accordance to figures:Figure 5- Typical Pot Head Type Layout and ConfigurationFigure 6- Typical Pot Head Type ConnectionFigure 7- Typical AC and DC Track Circuit ConnectionsFigure 8- Typical Westrack Track Circuit Connections2. For Level crossing predictor track connections shall be in accordance with:Figure 9- Typical HXP and GCP Track Circuit Connections3. Bonding of rail joints for track circuit continuity shall be by means of head ofrail bonding utilising two (2) 6 mm 2 flexible copper bonds per rail joint andwelded to the rail head.10.7 Reuse of Equipment1. Where the Constructor has intentions to reuse the existing track circuitequipment; the equipment shall be refurbished to the Infrastructure Managersrequirements.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 4510.8 Commissioning Work1. All train detection systems and associated areas shall be tested inaccordance with the <strong>VRIOGS</strong> 12.5 Testing and Commissioning of SafetyRelated Signalling Systems or Infrastructure Manager Specifications.NOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
46 <strong>VRIOGS</strong> <strong>010.7</strong> Revision AFigure 5 Typical Pot Head Type Layout and ConfigurationNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 47Figure 6 Typical Pot Head Type ConnectionNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
48 <strong>VRIOGS</strong> <strong>010.7</strong> Revision AFigure 7 Typical AC and DC Track Circuit ConnectionsNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 49Figure 8 Typical Westrack Track Circuit ConnectionsNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
50 <strong>VRIOGS</strong> <strong>010.7</strong> Revision AFigure 9 Typical HXP and GCP Track Circuit ConnectionsNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 51SECTION 11.0LIST OF FIGURESFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7Figure 8Figure 9Traverse Bonding of Electrified AreaPoint of Separation and Extent of ImmunizationImmunization of Adjacent Rail CorridorBonding of Traction Return and Fault ProtectionTypical Pot Head Type Layout and ConfigurationTypical Pot Head ConnectionTypical AC and DC Track Circuit ConnectionsTypical Westrack Track Circuit ConnectionsTypical HXP and GCP Track Circuit ConnectionsNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
52 <strong>VRIOGS</strong> <strong>010.7</strong> Revision ASECTION 12.0Table 1Table 2Table 3Table 4Table 5Table 6LIST OF TABLESRails Required for Traction Return CurrentResistance of Standard Rail SectionDistance between cross bonds where substations are less than5.0 km apartDistance between cross bonds where substations are greaterthan 5.0 km apartDC Voltage Drop across track relay on a single rail trackUse of Cable for Traction Bonding and Track CircuitConnectionsNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
<strong>VRIOGS</strong> <strong>010.7</strong> Revision A 53SECTION 13.0REFERENCESStandards and Specifications:• ARTC Specification ESD-07-02 ARTC Track Bonding and SignallingInfrastructure in Electrified Areas• ARTC Standard PDS 10 – Safe Limits of DC Voltages• AS 3000 Wiring Rules• AS 2832.1 Cathodic protection of metals. Part 1:Pipes and Cables• Connex Traction Cross Bond Design Guideline CML-8.10-PR-310 v0.2• EN 50121-4:2006 Railway Applications-Electromagnetic Compatibility-Part4:Emission and Immunity of the Signalling and Communications Apparatus• EN 50122-1:1998 Railway Applications-Fixed Installations-Part 1:ProtectiveProvisions relating to Electrical Safety and Earthing• EN 50122-2:1999 Railway Applications-Fixed Installations-Part 2:ProtectiveProvisions against the effects of stray currents by D.C Traction Systems• <strong>VRIOGS</strong> 012.1 Standard for Signalling Design and Documentation• <strong>VRIOGS</strong> 012.2 Specification for Signalling Supply, Construction andInstallation• <strong>VRIOGS</strong> 012.5 Testing and Commissioning of Safety Related SignallingSystems• <strong>VRIOGS</strong> 012.6 Signalling Cable SpecificationsDrawings:• MS97/0730 Arrangement of Bonds For Tangential Points• STD G0007 Spark Gap Earthing Device• STD_G0049 Point Trackside Labelling for Control Number and “N&R” Labelsto Indicate Lay of Points• STD_G0061 Track Circuit Series Bonding Arrangement• STD_G0066 Negative Connection Junction Box• STD_G0097 Cross Bonding Typical Arrangement-Electrified Area• STD_G0153 Typical Arrangements of Bonding at Points and Crossings• STD_G0154 Track Circuit Bonding at Points and CrossingsNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.
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