Solid State Interlocking
SSI utilises a 2-out-of-3 redundancy architecture, whereby all safety-critical functions are performed in three separate processing lanes and the results voted upon.Geographic interlocking data, relating to the area of railway under control, is installed using EPROMs contained in plug in memory modules.The second phase of the Docklands Light Railway in 1987, including the extension to Bank, the re-design of the Poplar / Canary Wharf layout and the reduction of the technical headway to under 2 minutes, saw the expansion of the SSI installation.Australia is an extensive user of SSI, particularly New South Wales, where it is installed at busy locations such as Hurstville - Oatley, North Sydney, Wyong, Granville, Enfield, Blacktown, Olympic Park and others within the Transport Asset Holding Entity network.Due to the success of SSI within the UK market, Alstom and WRSL have released products (Smartlock and Westlock respectively) which copy a number of its features.
processor-based interlockingBritish Rail's Research DivisionGEC-General SignalWestinghouse Signals Ltdsafety-criticalEPROMssignalspointstrack circuitrelaystwisted pairfibre-optic cablepulse-code modulationGreat BritainWestern EuropeanDingwallLeamington SpaDocklands Light RailwayTransport Asset Holding EntityAlstomWestlockarbitrary limitRailway signallingBlock systemsAbsolute block signallingAutomatic block signalingCentralized traffic controlCommunications-based train controlDirect traffic controlEuropean Train Control SystemMoving blockRadio Electronic Token BlockTrack Warrant ControlTrain order operationSignalling controlBlock postIntegrated Electronic Control CentreInterlockingLever frameRail operating centreWestlock InterlockingApplication of railway signalsCab signallingNorth American railroad signalsRailway semaphore signalAxle counterTrack circuit interrupterTreadleTrain protectionAdvanced Civil Speed Enforcement SystemAutomatic train controlAutomatic train operationAutomatic train protectionAutomatic Train Protection (United Kingdom)Automatic train stopAutomatic Warning SystemAutomatische treinbeïnvloedingBaliseCatch pointsChinese Train Control SystemCityflo 650 CBTCContinuous Automatic Warning SystemContrôle de vitesse par balisesEBICABIntegra-SignumInteroperable Communications Based SignalingCrocodileKorean Train Control SystemLinienzugbeeinflussungPositive Train ControlPulse code cab signalingPunktförmige ZugbeeinflussungRS4 CodiciSelTracSistema Controllo Marcia TrenoSlide fenceTrain automatic stopping controllerTrain Protection & Warning SystemTrain stopTrainguard MTTransmission balise-locomotiveTransmission voie-machineLevel crossing signalsCrossbuckWigwagE-signalWayside hornAdtranzAŽD PrahaFederalGeneral ElectricGriswoldHitachiHyundai RotemMagneticProgress RailSafetranSiemensSmith and YardleyThalesUnion SwitchWestinghouse Brake & SignalWestinghouse Rail SystemsTransport CanadaAustraliaBavariaBelgiumCanadaFinlandFranceGermanyGreeceNetherlandsNew ZealandNorth AmericaNorwayPolandSwedenSwitzerlandThailandUnited Kingdom