Signalling control
The raised design of most signal boxes (which gave rise to the term "tower" in North America) also provided the signalman with a good view of the railway under his control.With the jump to all electronic logic, physical presence was no longer needed and the individual control points could be consolidated to increase system efficiency.Another advancement made possible by the replacement of mechanical control by all-electric systems was that the signalman's user interface could be enhanced to further improve productivity.Finally, the use of Automatic Route Setting removed the need for any human input at all as common train movements could be fully automated according to a schedule or other scripted logic.Signal boxes also served as important communications hubs, connecting the disparate parts of a rail line and linking them together to allow the safe passage of trains.Later, the telephone put centralized dispatchers in contact with distant signal boxes, and radio even allowed direct communication with the trains themselves.Track circuits transmit train locations to distant control centers and data links allow direct manipulation of the points and signals.In a signal box with a control panel, the levers are replaced by buttons or switches, usually appropriately positioned directly onto the track diagram.Both in the UK and Ireland, however, mechanical signalling is still relatively common away from the busiest lines; in Europe, there is also a considerable amount in Germany, Poland, and the Czech Republic.
The Switch TowerClass 66Bardon HillLeicestershireMidland Railwaylever framerail transportrailway signalsblock systemstimetablehuman signal operatorlineside signalling equipmentswitchesinterlockingDes Plainesmechanical meansLondon & Croydon RailwayBricklayers Armspointssemaphore signalrelay logiccontrol devicespoint-and-clicktouchscreenAutomatic Route SettingTrack circuitsMorse codeKnockcrogheryIrelandBREL YorkIntegrated Electronic Control CentreRail Operating CentreKrzeszowiceheritage railwaysrailway stationsSignal gantryGreat CentralLong Island Rail RoadJamaicaNew York CityChicago Transit Authoritycontrol towerHarrisburgBirmingham New Street Signal BoxRailway signallingIan Allan PublishingTrainsAbsolute block signallingAutomatic block signalingCentralized traffic controlCommunications-based train controlDirect traffic controlEuropean Train Control SystemMoving blockRadio Electronic Token BlockTrack Warrant ControlTrain order operationBlock postSolid State InterlockingWestlock InterlockingSignalsApplication of railway signalsCab signallingNorth American railroad signalsRailway semaphore signalAxle counterTrack circuitTrack 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 hornAdtranzAlstomAŽD PrahaFederalGeneral ElectricGriswoldHitachiHyundai RotemMagneticProgress RailSafetranSiemensSmith and YardleyThalesUnion SwitchWestinghouse Brake & SignalWestinghouse Rail SystemsTransport Canada