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108Lesson1RailroadSwitch(铁道道岔)
Introduction
Arailroadswitchisamechanical
installationenablingtrainstobeguided
fromonetracktoanother.
InFigure1,railtrackAdividesinto
two:
trackB(thestraighttrack)andtrackC
(thedivergingtrack).Theswitchconsists
ofthepairoflinkedtaperingrails,knownaspoints(switchrailsorpointblades)lyingbetweenthe
divergingouterrails(thestockrails).Thesepointscanbemovedlaterallyintooneoftwopositions
soastodeterminewhetheratraincomingfromAwillbeledtowardsBortowardsC.2Atrain
movingfromtheAdirectiontowardseitherBorCissaidtobeexecutingafacing-pointmovement.
Unlesstheswitchislocked,atraincomingfromBorCwillbeledtoAregardlessoftheposition
ofthepoints,asthevehicle'swheelswillforcethepointstomove.Passagethroughaswitchinthis
directionisknownasatrailing-pointmovement.
Aswitchcanbedescribedbythedirectioninwhichthedivergingtrackleavesthestraighttrack.
Aright-handswitchhastrackCtotherightofastraighttrackformedbyAandB.Aleft-handswitch
hastrackCtotheleft.
Astraighttrackisnotalwayspresent,howeverbothtracksmaycurve,onetotheleftandoneto
therightorbothtracksmaycurve,withdifferingradii,inthesamedirection.
Theoperationofarailroadswitch
InFigure2,theredtrackistheonetravelled
duringafacing-pointmovement.Theswitch
mechanism,showninblack,maybeoperated
remotelyusinganelectricmotororleverfroma
nearbygroundframe.
Arailroadcar'swheelsareguidedalongthe
tracksbyconingofthewheels.Onlyinextreme
casesdoesitrelyontheflangeslocatedonthe
insidesofthewheels.Whenthewheelsreachthe
switch,thewheelsareguidedalongtheroute
determinedbywhichofthetwopointsis
connectedtothetrackfacingtheswitch.Inthe
illustration,iftheleftpointisconnected,theleftwheelwillbeguidedalongtherailor'thatpoint,
andthetrainwilldivergetotheright.Iftherightpointisconnected,therightwheel'sflangewillbe
guidedalongtherailofthatpoint,andthetrainwillcontinuealongthestraighttrack.Onlyoneofthe
109
pointsmaybeconnectedtothefacingtrackatanytime;thetwopointsaremechanicallylocked
togethertoensurethatthisisalwaysthecase.
Amechanismisprovidedtomovethepointsfromonepositiontotheother(changethepoints).
Historically,thiswouldrequirealevertobemovedbyahumanoperator,andsomeswitchesarestill
controlledinthisway?
However,mostarenowoperatedbyaremotelycontrolledelectricmotororby
pneumaticorhydraulicactuation.
Inatrailing-pointmovement,thewheelswillforcethepointstotheproperposition.Thisis
sometimesknownasrunningthroughtheswitch.Ifthepointsarerigidlyconnectedtotheswitch
controlmechanism,thecontrolmechanism'slinkagesmaybebent,requiringrepairbeforetheswitch
isagainusable.Forthisreason,switchesarenormallysettotheproperpositionbeforeperforminga
trailing-pointmovement.
Components
Points
Thepoints(switchrailsorpointblades)arethemovablerailswhichguidethewheelstowards
eitherthestraightorthedivergingtrack.Theyaretaperedonmostswitches.IntheUKand
Commonwealthcountries,thetermpointreferstotheentiremechanism,whereasinNorthAmerica
thetermrefersonlytothemovablerails.
Frog
Thefrog(commoncrossing)referstothecrossingpointoftworails.Thiscanbeassembledout
ofseveralappropriatelycutandbentpiecesofrailorcanbeasinglecasting.5Afrogformspartofa
railroadswitch,andisalsousedinaleveljunction(flatcrossing).
Onlineswithheavyand/orhigh-speedtraffic,aswing-nosecrossingisoftenused.6Asthename
implies,thereisasecondsetofpointslocatedatthefrog.Thiseffectivelyeliminatesthegapinthe
railthatnormallyoccursatthefrog,solongastrainsaremovinginthedirectionthattheswitchis
alignedto.Thisuseoftheword"frog"derivesfromtheappearanceofthetriangularassemblageof
railswhichrecallsthefrogofahorse'shoof.
Guardrail(checkrail)
Aguardrail(checkrail)isashortpieceofrailplacedalongsidethemain(stock)railopposite
thefrog.Theseexisttoensurethatthewheelsfollowtheappropriateflangethroughthefrogandthat
thetraindoesnotderail.Generally,therearetwooftheseforeachfrog,onebyeachouterrail.Guard
railsarenotrequiredwitha"self-guardingcastmanganese"frog,astheraisedpartofthecastingserve
thesamepurpose.Thesefrogsareforlow-speeduseandarecommoninrailyards.
Switchmotor
Aswitchmotorisanelectricorpneumaticmechanismthatalignsthepointswithoneofthe
divergingroutes.
Pointlever
Apointleverandaccompanyinglinkagesareusedtoalignthepointsofaswitchmanually.This
leveranditsaccompanyinghardwareareusuallymountedtoapairoflongsleepersthatextendfrom
theswitchatthepoints.Theyareoftenusedinaplaceofaswitchmotor.Insomeplaces,maybe
operatedfromagroundframe.
110
Joints
Jointsareusedwherethemovingpointsmeetthefixedrailsoftheswitch.Theyallowthepoints
tohingeeasilybetweentheirpositions.
NewWordsandExpressions
Railroadswitch铁路道岔
Diverge分开;偏离;分歧:
分道扬镳
taper(使)一端逐渐变细
Pointblades尖轨
Stockrails基本轨
trailing拖尾的,曳尾的,被拖动的,蔓延的
passage通过,经过
lateral侧面的,从旁边的,至侧面的
execute处决,执行,实现;使生效
right-handswitch右开道岔
left-handswitch左开道岔·
radii半径
Flange(机械等的)凸缘,(火车的)轮缘,
Illustrationn.插图,图表,图案,例证,实例,·说明,图解,图示
Electricmotor电机
Pneumatic充气的,由压缩空气操作[推动]的,风动的
Hydraulicadj.液力的,液压的
Actuationn.刺激,冲动
Trailingdirection背向
Linkagen.连接;结合:
联系;联动装置
guardrail(checkrail)护轨
align使结盟,使成一行,使成一线
Manuallyadv.用手地
hinge用铰链连接(某物),给(某物)装上铰链
derail出轨
RegardlessOf不管,不顾
Solongas只要
Derivefrom由……起源
OutOf由….”制成
Beusedto过去习惯于
divideinto分成;分为
whether..。
or或者……或者
111
NotestotheText
1.Arailroadswitchisamechanicalinstallationenablingtrainstobeguidedfromonetrackto
another.
译文:
铁路道岔是一个使火车由一个股道转入另一个股道的连接设备。
,,
“enabling”引导的部分是现在分词作定语,后置,修饰“amechanicalinstallation",
如:
Thefarmersworkinghereareverybusy.
2.Thesepointscanbemovedlaterallyintooneoftwopositionssoastodeterminewhetheratrain
ComingfromAwillbeledtowardsBortowardsC.·
译文:
这两个尖轨能从侧面移动到两个位置中的任何一个,从而确定火车是轨道A驶向
轨道B,还是由轨道A驶向轨道C。
3.Amechanismisprovidedtomovethepointsfromonepositiontotheother(changethepoints).
Historically,thiswouldrequirealevertobemovedbyahumanoperator,andsomeswitchesare
Stillcontrolledinthisway.
译文:
为使尖轨从一个位置移到另一个位置而设置了一种机械装置。
但历史上,则是由人使
用一个操作手柄来移动尖轨,如今仍有一些道岔是采用这种方法。
4.Ifthepointsarerigidlyconnectedtotheswitchcontrolmechanism,thecontrolmechanism's
Linkagesmaybebent,requitingrepairbeforetheswitchisagainusable.
译文:
如果尖轨与道岔控制装置紧密地连接在一起,那么控制装置的连接部分会弯曲变形,
在道岔再次使用之前需要维修。
5.Thefrog(commoncrossing)referstothecrossingpointoftworails.Thiscanbeassembledoutof
Severalappropriatelycutandbentpiecesofrailorcanbeasinglecasting.
译文:
辙叉(公共主叉部分)是指两轨交叉的部分。
辙叉可以由几段经过适当切割和弯曲的
钢轨组装而成,也可以是一个单个的铸件。
“outof'’在这里表示“由……制成”。
如:
Shemadeahatoutofbitsofoldmaterial.她用旧的零碎材料做了一顶帽子。
6.Onlineswithheavyand/orhigh-speedtraffic,aswingnosecrossingisoftenused.
译文:
在重载或者高速运输线路上,经常使用活动心轨道岔。
,,
“aswingnosecrossing是指“Thecrossinghasflexiblymovingpointandsplicerails"。
ExercisestotheText
ITranslatethefollowingtermsintoChinese.
(1)railroadswitch
(2)thestraighttrack(3)thedivergingtrack
(4)switchrailsorpointblades(5)afacing-pointmovement(6)atrailing-pointmovement
(7)right-handswitch(8)left-handswitch(9)guardrail(checkrail)
(10)frog(commoncrossing)(11)switchmotor,
ⅡDecidewhethereachofthefollowingstatementsistrueorfalseaccordingtothetext.
(1)Fromthetextweknowthepointbladescanbemovedlaterallyintooneoftwopositionssoas
TodeterminewhetheratraincomingfromAwillbeledtowardsBortowardsC.()
112
(2)AtrainmovingfromtheAdirectiontowardseitherBorCissaidtobeexecutingatrailing
-pointmovementinFigure1.()
(3)Aright-handswitchhastrackCtothefightofastraighttrackformedbyAandB.()
(4)Fromthetextwecanconcludethatsomeswitchesarestillrequirealevertochangethepoints
byahumanoperatortoday.()
IIIAnswerthefollowingquestionsaccordingtothetext.
(1)What'sthefunctionofthejoints?
(2)Wherearepointsleveranditsaccompanyinghardwareusuallymounted?
(3)Isthecheckrailashortpieceofrailplacedalongsidethemainrailoppositethefrog?
(4)Whichdoesarailroadswitchconsistof?
IVTranslatethefollowingpassageintoChinese.
Classification
Thedivergenceandlengthofaswitchisdeterminedbytheangleofthefrog(thepointinthe
switchwheretworailscross)andthecurvatureoftheswitchblades.Thelengthandplacementofthe
othercomponentsaredeterminedfromthisusingestablishedformulasandstandards.Thisdivergence
ismeasuredasthenumberofunitsoflengthforasingleunitofseparation.InNorthAmericathisis
generallyreferredtoasaswitch's"number".Forexample,ona"number12'switch,therailsare
oneunitapartatadistanceoftwelveunitsfromthecenterofthefrog.IntheUnitedKingdompoints
andcrossingsusingchairedbullheadrailwouldbereferredtousingaletterandnumbercombination.
Theletterwoulddefinethelength(andhencetheradius)oftheswitchbladesandthenumberwould
definetheangleofthecrossing(frog).T
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