NewWordsandExpressionssteer[st??(r)]v.掌舵，駕駛steeringgear

操舵裝置，舵機(jī)rudder[?r?d?(r)]n.舵，方向舵，操舵duplicate[?dju?pl?ke?t,?dju?pl?k?t]a.完全一樣的：復(fù)制的impair[?m?pe?(r)]v.損害；削弱helm[helm]n.舵輪，舵機(jī)fined[fa?nd]v.處…以罰金detain[d??te?n]v.拘留；扣押NewWordsandExpressionsbuckle[?b?kl]n.扣，彎扣entrapment[?n?tr?pm?nt]n.滯留tiller[?t?l?(r)]n.舵柄，翻轉(zhuǎn)裝置Apropelleristhedevicethatforcestheshipforwardthroughseawater,butwhatisitthathelpsinchangingaship’scourseordirection?Itcertainlyrequiresquiteabitofefforttoturnaroundahugeshipandtheremustbesomereliableandefficientmechanismtoachievethesame.Arudder,attachedandsuspendedinsuchawaythatitstaysjustbehindthepropeller,isusedtodirectaship.Therudderisinternallyconnectedtoasteeringgear,whichthroughitsmechanism,controlsthemovementoftherudderandthusthatoftheship.Thesteeringsystemofashipprovidesaresponsetothesignalfromthebridgebymovingtherudderinthedesireddirection.Inthisarticlewewilllearnaboutthehydraulicsteeringsystemsusedinmarineapplications.Thesteeringgearsystem(seeFig.23-1)hasthreemainparts:controlequipmentpowerunittransmissiontotherudderstock.Inbrief,theoperationofthesteeringgearcanbeexplainedas-Withthehelpofthecontrolsystem,asignalofdesiredrudderangleissentfromthebridge.Thissignalactivatesthepowerunitwithwhichtherudderisattached.Theruddermoveswiththehelpofthepowerunittilltherightangleisreached.SteeringGearSystemSteeringGearSystemFig.23-1SteeringGearSystemsforShipAllshipsmustbeprovidedwithanefficientmainandauxiliarysteeringgearandexceptforverysmallvessels,themainsteeringgearmustbepoweroperated.TheauxiliarysteeringgearmustalsobepoweroperatedwhentheRulediameteroftherudderstockexceeds230mmforpassengervesselsand250mmforcargovessels,althoughthelowerfigureof230mmislikelytoapplytoallvesselsinafewyearstime.Whilstitisdesirablethatthemainandauxiliarysteeringgearsshouldbeentirelyindependentofeachother,thisisrarelyachievedinpracticesincebothgearscommonlyshareahydraulicactuatorwhichmayormaynotbeduplicated.MainandAuxiliarySteeringGearThemainsteeringgear,withtheshipatherdeepestseagoingdraught,mustbecapableofputtingtherudderoverfromanangleof35°ononesideto35°ontheothersidewiththeshiprunningaheadatmaximumservicespeed,itmustalsobecapableofputtingtherudderoverfrom35°oneithersideto30°ontheothersideinnotmorethan28sec,underthesameconditions.

主操舵裝置必須滿足能在船舶處于最深航海吃水并以最大營(yíng)運(yùn)航速前進(jìn)時(shí)將舵自任何一舷35°轉(zhuǎn)至另一舷的35°，并且于相同的條件自一舷的35°轉(zhuǎn)至另一舷的30°所需的時(shí)間不超過(guò)28s。MainandAuxiliarySteeringGearTheauxiliarysteeringgearneedonlybecapableofsteeringtheshipatnavigablespeedbutitmustbecapableofbeingbroughtspeedilyintoactioninanemergency.Navigablespeedisgenerallyconsideredasonehalfofthemaximumservicespeedaheador7knots,whicheveristhegreater.輔助操舵裝置只需能以可航航速操縱船舶，但必須能在緊急情況下迅速發(fā)揮作用。可航航速一般被認(rèn)為是最大航行速度的一半或7節(jié)，兩者中以較大者為準(zhǔn)。MainandAuxiliarySteeringGearWherethemainsteeringgearcomprisestwoormoreidenticalpowerunits,anauxiliarysteeringgearneednotbefittedinapassengervesselprovidedthatwithoneunitoutofactionthegeariscapableofputtingtherudderoverin28secinthemannerabove.Asimilarrulingappliesforcargovesselsbutwiththelessonerousconditionthatthesteeringgearneedonlymeettheaboverequirementforauxiliarygear,withallpowerunitsoperatingsimultaneously.當(dāng)船舶配備的主操舵裝置具有兩臺(tái)或幾臺(tái)相同的動(dòng)力設(shè)備時(shí)，可不設(shè)置輔助操舵裝置。但是對(duì)客船來(lái)說(shuō)，任一臺(tái)動(dòng)力設(shè)備不工作時(shí)，主操舵裝置仍能按規(guī)定（28s）進(jìn)行操舵；但對(duì)條件沒有那么繁雜的貨船來(lái)說(shuō)，則在所有動(dòng)力設(shè)備都工作時(shí)，主操舵裝置能按規(guī)定進(jìn)行操舵。MainandAuxiliarySteeringGearFortheabovetoapply,itisessentialandsofarasisreasonableandpracticable,thatasinglefailureinthemainsteeringgearpowerunitsorpipingwillnotimpairtheintegrityoftheremainingpartofthesteeringgear.Thesteeringgears,bothmainandauxiliary,arerequiredtobeofadequatestrengthfortheirrespectivedutiesasalreadydefined.Themainsteeringgearmustalsobedesignedsoastoensurethatatmaximumasternspeedneitherthegearnortherudderstockwillbedamaged(主、輔操舵裝置應(yīng)該有符合規(guī)定的強(qiáng)度。主操舵裝置應(yīng)設(shè)計(jì)成在船舶以最大倒車速航行時(shí)主操舵裝置和舵桿不致?lián)p壞).MainandAuxiliarySteeringGearRuddersFig.23-2RudderInpassengershipswheretheRulediameteroftherudderstockexceeds230mm,analternativesteeringpositionremotefromthemainpositionistobeprovidedandmustbearrangedsothatfailureofeithersystemcannotrendertheothersysteminoperable(對(duì)于舵柄處舵桿直徑大于230mm的客船，須設(shè)置一個(gè)與主操舵位置相對(duì)獨(dú)立的備用操舵位置，而該位置的布置須使任何一個(gè)系統(tǒng)的故障不能使另一個(gè)系統(tǒng)不能操作).Provisionmustbemadetotransmitordersfromthebridgetothealternativeposition.Theexactpositionoftherudder,ifpoweroperated,mustbeindicatedatthemainsteeringpositionandthemethodofindicationmustbeindependentofthesteeringgearcontrolsystem.RuddersAnefficientlockingorbrakearrangementmustbefittedtoallsteeringgearstoenabletheruddertobemaintainedstationaryifnecessary.Allpoweroperatedgearsmustbefittedwitharrangementsforrelievingshock;thisisarequirementtoprotectagainsttheactionofheavyseasagainsttherudder.Thereliefvalveprovidedwithsomefixeddisplacementpumpsoperatinghydraulicsteeringgears.Suitablestoppingarrangementsaretobeprovidedfortheruddersoastorestrictthetotaltravel.Cutoutsonthesteeringgeararetobearrangedtooperateatasmallerangleofhelmthanthosefortherudder.RuddersSteeringgeartestingcomprisesofaseriesoftestsonthewholesteeringgearsystemthatshouldbecarriedoutreligiously.Thetestsinclude:Testingofthemainsteeringgearoperation.Testingoftheauxiliarysteeringgearsystem.Testingofthemainandstandbypump.Testingofthetele-motorsystem,remotelyoperatedfrombothbridgeandenginecontrolroom.Testingsteeringgearoperationwithemergencypowersupply.Testingofrudderindicationsystemwithrespecttothetrueangleofrudder.Testingofremotecontrolalarmsandsteeringgearpowerunits.Testingofautomaticisolatingarrangements.SteeringGearTestingOilLeakages:Portstatecontrolshaveverystrictpolicyofzeroleakagefromship’ssteeringgear.Manyshipshavebeenfinedanddetainedduetosuchfaultspointedoutduring

portstatecontrolinspection.Still,oilleakagefromthesteeringgearisoneofthemostcommonproblemsonships–aresultofmachinerysystemshavingseveralmovingpartsoperatedbyhydraulicoil.Someofthemain

areasofleakagesarecylinder-ramsealinhydraulicramtypesteeringgearandsealinthechambersofarotaryvanepump.Needlesstosay,anykindofleakagefromsteeringgearsystemmustberectifiedimmediately.CommonProblemsFoundinSteeringGearSystemofShipsAnothercommonproblemobservedinsteeringgearsystemisthedifferenceintheanglegivenatthehelmandtheactualrudderangle.Thisoccursduetowrongorinsufficientadjustmentofcontrolandrepeatbacklever.Torectifythisproblem,theturnbuckleattachedtotherodofcontrolandrepeatbackleveraretobepreciselyadjusted.DifferenceintheActualRudderAngleandOrderedHelmAngle:Thefuelconsumptionoftheshipgreatlydependsontheefficiencyofsteeringgearoperation.Ifthesteeringgearisoperatingunsatisfactory,itwillleadtodelayintheETAoftheshipandincreasemainenginefuelconsumption.Commonreasonforthisproblemismalfunctioningofsafetyvalvesorbypassvalvesinthesystem.Anyprobleminthecontrolandrepeatbackleverwillalsoleadtounsatisfactorysteering.Tosolvethisissue,safetyandbypassvalveoperationaretobecheckedatregularintervals.Ifanyproblemisnoted,sametoberecitedattheearliest.Forcontrolandrepeatbacklever,theturnbuckleattachedtotherodofcontrolandrepeatbackleveraretobepreciselyadjusted.UnsatisfactorySteering:Excessivenoiseandvibrationsfromthesteeringgearindicatesentrapmentofairinthesystem.Duetoairbubblesintheoil,pumpsandpipingsaresubjectedtoairhammerleadingtovibrationandheavynoise.Airmustberemovedfromthesystemusingventvalveprovidedinthecylinderandpumpspeciallyafterthesystemisreplenishedwithnewoil.Ifthevalvelocatedintheoilsupplytankofthesteeringgearisthrottledorclosed,itwillagaindevelopairbubblesinthesystem.Ensurethatthisvalveisalwaysopenwhenthesystemisinoperation.ExcessiveNoisefromSteeringGear:Oilistheoperatingmediainthesteeringgearsystem.Anyabnormalityintheparametersofoilwillleadtootheroperationsrelatedproblemsinthesteeringgear.Ifthereisincreaseintheoiltemperature,itwilldirectlyreducetheviscosityoftheoilandhamperthesteeringoperation.Themostcommoncauseofincreaseinoiltemperatureislowoillevelinthesystem.Thus,ensurethatlowoillevelalarminthetankisworkingandreplenishtheoilwhenrequired.HighOilTemperature:TheSOLASrequirementforsteeringgearsaysthatthesystemmustbecapableofputtingtherudderoverfrom35°ononesideto35°ontheothersideoftheshipatitsdeepestseagoingdraughtandrunningatmaximumaheadservicespeed.Itmaysometimeshappenthatthemaximumanglereachedbytherudderislessthanprescribedortherudderisovershootingthe35°anglemark.Oneofthemainreasonsforthisproblemismalfunctioningoflimitswitchfittedontherepeatbackunitorontheautopilot(造成這一問題的主要原因之一是裝在回動(dòng)裝置或自動(dòng)駕駛儀上的限位開關(guān)失靈).Replacethemalfunctionedlimitswitchoradjustthelimitswitchtomaximumprescribedrudderangle.RudderMovementisWithinorBeyondtheLimit:Thereisalwaysaprovisionoflocalmaneuveringinthesteeringgearforemergencysituationiftheremotecontroloperationfails.Somecommonreasonsforfailureofremovecontrolsare:Breakdownofhydraulicpumps:Otherhydraulicpumptobestartedinsuchcases.Malfunctionoftransfervalve.MalfunctioningofhydraulicbypassvalveinthepumpOilleakageProblemintelecontrolsystem.NoSteeringfromRemotecontrol:On29April2011,thePanamaregisteredbulkcarrierDumungroundedwhiledepartingtheportofGladstone,Queensland.Priortothegrounding,theship’ssteeringappearedtohavestoprespondingtobridgecommandswhenthelinkagebetweenthetillerandrudderangletransmitterdetached(在擱淺之前，當(dāng)舵角發(fā)送器與舵柄之間的傳動(dòng)桿件斷開時(shí)，船舶的舵機(jī)裝置已經(jīng)停止了對(duì)駕駛臺(tái)指令的響應(yīng)).Thesteeringgearcontinuedtooperatenormally,butthetransmitterlostitsinputsignaland,asaresult,thebridgemountedrudderangleindicatorstoppedworking.Suchcasesarerarebuttheydooccur(舵機(jī)正常工作，但舵角發(fā)送器失去其輸入信號(hào)，因此安裝在駕駛臺(tái)上的舵角指示器停止工作。這種情況很少見，但確實(shí)發(fā)生過(guò)).Toavoidsuchaccidents,ensurethatthedutyofficermusttakearoundbeforeeverymaneuveringordepartureporttocheckallthelinkagesintheengineroom.RudderAngleTransmitterandTillerLinkFailure:

Exercises1.Whichofthefollowingistrueaboutthesignaltransmissionofthesteeringgear?A.thebridge---thesteeringgear---therudderB.therudde---thebridge---thesteeringgearC.thebridge---therudder---steeringgearD.thesteeringgear---therudder---thebridge2.Themainsteeringgearmus