railroad signaling 101 · 2020. 10. 14. · railroad signaling 101 • overview of signaling, not a...
TRANSCRIPT
RailroadSignaling101
AnOverviewandHistory
DavidA.Ellis Division12,MCR,NMRA
RailroadSignaling101
• Overviewofsignaling,nota“howto”• Focusonprototypesratherthanmodeling• Somebasicterms• Whyrailroadsdevelopedsignalingsystems• Chronologicalapproach• Basicoverviewwithoutallthenuances• Bibliographyhassourceswithmoredetails
SignalTerms
• Aspect:Whatitlookslike--thecolororthepositionofthebladeorrowoflights
• Name:Thewordsusedwhentalkingaboutit
• Indication:Whatshouldbedonewhenitisseen
WhyDifferentSignalSystems?
• Purpose–Safetyandincreasetraffic• Era–Othertechnology:telegraph,radio,etc.• Prototype–Whattherealrailroaddid• DispatchingSystem–Signalsystemsmatchwithcorrespondingdispatchingsystem
HandandFlagSignals
• PRRrulebookIllustrationfrom:
• TonyKoesterhasadaptationsformodelers
WhistleSignalsRule 14 Engine Whistle Signals
A short sound is designated by “0” and a long sound by a “- -”
0 Apply brakes -- Stop
---- Release brakes – Proceed Forward
000 Release Brakes – Reverse Back
----0-- Grade Crossing (last long extended)
Ring Bell when public contact possible and on bridges!
TrainOrderSignals
MikeHauk’sLayout,PhotobyMikeHaukwithpermission
TrainOrderSignals
• UsedwithT&TOdispatching.
• Typicalsignalwasupper-quadrantsemaphore
• Signalswhetherordersormessagesforpick-up.
ManualBlockSignals
• Earlysignalingsystem• Mainlineisdividedintosectionsorblocks• Operatorkeepingtrackoftrainsenteringandleavingtheblockstationedateachend
• Operatorabletocommunicatewithotheroperatorsand/ordispatcher
• Eachblockstationequippedwithasignal
ManualBlockSignals
• Signalaspectssimilartotrainordersignalsorred,yellow,andgreen
• Theredaspectisastopsignal;theindicationistostopbecausetheblockisoccupied
• Theyellowaspectisaproceedatatrestrictedspeedsignal;theindicationistotravelslowenoughtobepreparedtostopshortofaprecedingtrain
• Thegreenaspectsignalstoproceed,theblockisclear
1956NewYorkCentralRulesoftheOperatingDepartmenthttps://nycshs.org/about-n-y-c/nycs-signal-rules/
AutomaticBlockSystem-ABS• InsimpleABS,alowvoltagetrackcircuitdetermineswhetherablockisoccupied.
• ABSpermittedshorterblocks,increasinglinecapacity,andrequiredfewernumbersofpersonnel,reducingcosts.
• ABSisapermissivesystem,aprotectiveoverlay,allowingtrainstofolloweachotherinasafemanner.
• AtypicalapplicationisusingABSwithadoubletrackmainlinewithonedirectionoftraveloneachtrack.
AutomaticBlockSignals--ABS• Threeblocks,traininthethirdblock,
travelingtotheright
• Redsignal,obstructioninnextblock• Yellowsignal,obstructedblockahead• Greensignal,noobstructionisexpected.• Whenthetrainmovestothenextblock,
redchangestoyellowandyellowtogreen.
Train
AbsolutePermissiveBlock-APB
• ABSwithextrasafetyfeatures• Singletrackmainlines• Preventopposingtrainsfrom“meeting”• Absolutesignalprotectionbetweenpassingsidings
TowerandTracksatDevalInterlockingC&NWBySlambo-Ownwork,CCBY-SA2.5,https://commons.wikimedia.org/w/index.php?curid=433758
InterlockingPlant
• Definition:Anarrangementofsignalandturnoutcontrolsinterconnectedtopreventconflictingmovementsthroughtracksatcrossings,junctions,andcrossovers.Thesemaybeoperatedmanually,automatically,orbyremotecontrol.
InterlockingSignals
• Name:ApproachSignal
• Aspect:Typicallyasearchlightsignalwithayellowlight.
• Indication:Proceedatrestrictedspeedpreparedtostopatnextsignal
• Name:HomeSignal• Aspect:Redorgreen• Indication:Absolute,red=stopbeforesignalgreen=freetoproceedatslowspeedthroughtheinterlocking
CentralizedTrafficControl
EdCronin’sB&LELayout
CentralizedTrafficControl-CTC
• TrafficControlSystem• Trainsrunonsignalindicationonly• CTCPanels• Interlockings,ABS,andtrafficlockingcombined
• Singledispatcheroverlargesectionofrailroad• Dispatchercontrolsandmonitors
Signaling 1.01 An Overview of Prototype-Model Signal Systems!
By Michael J. Burgett Division Engineer of Signals Chicago and Michigan Division Canadian National Railway
EduTRAIN™
PositiveTrainControlandSignals?
Bibliography• ABS,InterlockingandTCS/CTCbasicshttp://www.lundsten.dk/us_signaling/signalbasics/• JohnArmstrong’s1957Trainsmagazinearticlesonsignaling
http://nttmuseum.org/kids/signals.pdf• “RailroadSignals:WhatTheyDo,WhatTheyMean,”Trains
Magazine,FrankW.Bryan,RobertSMcGonigal,May1,2006,trn.trains.com/railroads/abcs-of-railroading/2006/05/railroad-signals• RealisticModelRailroadOperation2ndEdition,KalmbachBooks,
TonyKoester,2013• RailroadSignalsoftheU.S.:OtherFormsofSignalingwww.railroadsignals.us/other/hand/index.htm• WikipediaarticleonABS,https://en.wikipedia.org/wiki/Automatic_block_signaling