Signals Engineering Specification - Transport For NSW

SPG 1256COMMUNICATION LINKS FORSIGNALLING CONTROLVersion 1.1Issued 4 June 2013Owner:Chief Engineer, Signals & Control SystemsApprovedby:Warwick AllisonChief EngineerSignals & Control systemsAuthorisedby:Stephen TempletonPrincipal EngineerControl SystemsDisclaimerThis document was prepared for use on the RailCorp Network only.RailCorp makes no warranties, express or implied, that compliance with the contents of this document shall besufficient to ensure safe systems or work or operation. It is the document user’s sole responsibility to ensure that thecopy of the document it is viewing is the current version of the document as in use by RailCorp.RailCorp accepts no liability whatsoever in relation to the use of this document by any party, and RailCorp excludesany liability which arises in any manner by the use of this document.CopyrightThe information in this document is protected by Copyright and no part of this document may be reproduced, altered,stored or transmitted by any person without the prior consent of RailCorp.Engineering SpecificationSuperseded by T HR SC 01256 ST v1.0, 13/10/2016Engineering SpecificationSignalsConstruction Specification

Superseded by T HR SC 01256 ST v1.0, 13/10/2016RailCorp Engineering Specification — Signals - Construction SpecificationCommunication Links for Signalling ControlSPG 1256Document controlVersion1.01.1 RailCorpIssued 4 June 2013Date19 November 20124 June 2013Summary of changeNew documentClarificationsUNCONTROLLED WHEN PRINTEDPage 2 of 11Version 1.1

Superseded by T HR SC 01256 ST v1.0, 13/10/2016RailCorp Engineering Specification — Signals - Construction SpecificationCommunication Links for Signalling ControlSPG 1256Contents11.11.21.31.4General .4Introduction .4Definitions .4Referenced documents .4Background .522.12.22.32.4Impact of Failures .5General.5Conditional Failure .5Functional Failure.5Common Mode Failures.633.13.23.33.43.53.6Link Diversity.7General.7Duplication Without Diversity .7Cable Diversity .7Duct Diversity .7Route Diversity.7Physical Diversity .74Location Requirements .8General.8Control System to Interlocking .8Link Equipment .8Link Diversity.8Link Identification .8Link directness .8Link Latency .9Dedicated Restoration Links .9Common Locations .9Fallback Control Location.9Link Availability.9Link Security.10Link Failure.10Link Diagram .106Link Approval .11 RailCorpIssued 4 June 2013UNCONTROLLED WHEN PRINTEDPage 3 of 11Version 1.1

Superseded by T HR SC 01256 ST v1.0, 13/10/2016RailCorp Engineering Specification — Signals - Construction SpecificationCommunication Links for Signalling Control1General1.1IntroductionSPG 1256This standard establishes the minimum requirements for the provision of control andcommunication links between signalling control systems and the interlockings to meetreliability, availability and business continuity aims. This standard does not cover thetelecommunications equipment used to transfer data between signal interlockingequipment.There is an expectation that the telecommunications network will be designed to supporta signalling control system.1.2DefinitionsLink: A telecommunications connection between two pieces of control systemsequipment. The telecommunication interfaces are defined in EPG 1441, InterfaceDefinitions between Chief Engineer Signals and Communications & Control SystemDivision.Duplicated Link: Where the field equipment is duplicated then the grouping of the Linkbetween the A sides and the Link between the B sides of a duplicated control system isreferred to as a Duplicated Link. Where the field equipment is not duplicated then thecommunications equipment used to create the two links to the control centre is includedin the Duplicated Link.Link Failure: A Link Failure will be deemed to occur when a communication failure ormaintenance work results in loss of connection due to equipment not performing itsintended function or an unacceptable level of repetition, deletion, insertion, resequencing, corruption, or delay. For the definition of these terms refer to EN50159:2010, Railway Applications – Communications, Signalling and ProcessingSystems – Safety Related Communications in Transmission Systems.Functional Failure: The term Functional Failure is defined in TMGJ004, SignallingSafeworking Procedures Manual J, Failures. For the purposes of defining a FunctionalFailure of communication between two sites, a Functional Failure will be deemed to occurwhen a Link Failure occurs and the data is not properly transmitted between the sites byalternative means. Where there is a Duplicated Link between two sites then a FunctionalFailure will be deemed to occur when there are simultaneous Link Failures of both links.Conditional Failure:The term Conditional Failure is defined in TMGJ004, SignallingSafeworking Procedures Manual J, Failures. For the purposes of defining a ConditionalFailure of communication between two sites, a Conditional Failure will be deemed tooccur when a Link Failure occurs and there is no Functional Failure.1.3Referenced documentsTMGJ004, Signalling Safeworking Procedures Manual J, FailuresEN 50159:2010, Railway applications – Communications, signalling and processingsystems – Safety related communications in transmission systems.SPG1009, Standard Requirements for Signalling Electronic SystemsIncident Management Framework Part 2 RailCorpIssued 4 June 2013UNCONTROLLED WHEN PRINTEDPage 4 of 11Version 1.1

Superseded by T HR SC 01256 ST v1.0, 13/10/2016RailCorp Engineering Specification — Signals - Construction SpecificationCommunication Links for Signalling ControlSPG 1256SPG 1230 Design of Microlok II InterlockingESM102, Telecommunications Outdoor Cabling StandardESM105, Signalling Bungalow Communications Cabling StandardTMM P001, Copper Cable TerminationEPG 1441 Interface Definitions between Chief Engineer Signals and Communications &Control System Division.1.4BackgroundThere are three fundamental elements for determining a suitable configuration for controland communication links. These are:a)Reliability/availability andb)Route diversity andc)Location.The total link may consist of a series of separate hops that form the maincommunications path between the control and interlocking location. These links will havean inherent availability with duplication to enhance availability where required. Theduplicated paths should be physically diverse in order to mitigate common mode physicalfailures, however due to cost considerations there may be common locations where bothsides come together that can be subject to common mode physical faults.2Impact of Failures2.1GeneralThe availability and integrity of the Link is integral to the control system meeting thereliability requirements of Section 4.8, Reliability and Life, SPG1009, StandardRequirements for Signalling Electronic Systems. A Functional Failure will result in anoperational impact as specified in Table 1, Rail incident classification table, IncidentManagement Framework part 2.2.2Conditional FailureThe prompt repair of a Conditional Failure is essential to ensure that the availability ofeach link is achieved such that the required probability of a Functional Failure is notexceeded.2.3Functional FailureThe Operations Directorate classify incidents that result from a Functional Failure aseither level 1 (routine), level 2 (significant), level 3 (major) or level 4 (emergency). Thelevel of Functional Failure is specified in Table 1, Rail incident classification table,Incident Management Framework Part 2 with particular note to the significance of thelocation of the incident, extent of customer delay dependent on the time of day and theongoing ability to provide train services. Significant locations include the Sydney HarbourBridge, City Circle, ECRL, Underground Lines, Tunnels, Hawkesbury River Bridge, andsections where road access is difficult. The extent of delays and the time of day of theincident have a strong bearing on setting the incident level. The availability of RailCorpIssued 4 June 2013UNCONTROLLED WHEN PRINTEDPage 5 of 11Version 1.1

Superseded by T HR SC 01256 ST v1.0, 13/10/2016RailCorp Engineering Specification — Signals - Construction SpecificationCommunication Links for Signalling ControlSPG 1256communication links during an incident influences the ability to return services to normaloperations.A telecommunications fault which results in a Functional Failure of a single field locationgenerally result in at least a level 1 (routine) rail incident with level 3 (major) not beingunreasonable to expect.A telecommunications fault which results in a Functional Failure of a control centregenerally result in at least a level 3 rail incident with level 4 (emergency) not beingunreasonable to expect.A telecommunications fault which results in a prolonged Functional Failure of a controlcentre and the disaster recovery site will result in a level 4 rail incident.In all the above faults the resulting consequences typically last well beyond therectification of the fault.2.4Common Mode FailuresA Functional Failure will occur if there is a common mode equipment failure of duplicatedcontrol and communication links used for signalling purposes.The types of equipment common communication equipment, cable runs, air conditioning, power supplies.The types of events that may cause common mode failures Physical damage Construction or excavation damage, Derailment, Motor vehicle, Accident, Fire, Flood, Vandalism, Water [leakage], Acts of God. Electrical damage Lightning, Mains supply irregularities. Power supply loss, Maintenance action, Operator action, Equipment fault Equipment, Housing, Wiring, Terminals, Fusing etc. Terrorism, Gas leak, Building evacuation, Bomb threats, Alarm procedures. RailCorpIssued 4 June 2013UNCONTROLLED WHEN PRINTEDPage 6 of 11Version 1.1