DevelopmentofFeederMessengerWireTypeOverheadContactLinewithOneCopperMessengerWireTakahiroHAMADAAtsushiIWAINAKAResearcher,FormerResearcher,ContactLineStructures,PowerSupplyTechnologyDiv.Feedermessengerwiretypeoverheadcontactlineshavedrawnattentionrecentlyfromtheviewpointoflabor-savingformaintenance.AtypethatusestwoPH356mm2messengerwireswasintroducedintotheTokyodistrict,whileanotherthatusesanSBTACSR730mm2messengerwireintotheKansaidistrict.Intermsofthenumberofmessengerwires,theone-wiretypeismoreuseful,asitinvolvesasmallernumberofparts.Asthematerialforthewire,copperisbetterthanaluminum,sinceitdoesnotrequireconnectionwithdifferentmetals.Torealizetheadvantagesofthetwosystems,therefore,wedevelopedafeedermessengerwiretypeoverheadcontactlinethathasonlyonecoppermessengerwire.Keywords:feedermessengerwiretypeoverheadcontactline,PH730mm2messengerwire,currentcollectingcharacteristics1.IntroductionFeedermessengerwiretypeoverheadcontactlineshaveastructuretocombinethefunctionoffeederwiththemessengerwire.TheyhavedrawnattentionrecentlyinJapanfromtheviewpointoflabor-savingformaintenance.Theyusetwohard-drawncopperstrandedconductorPH356mm2messengerwiresintheTokyodistrictandanaluminumconductorsteel-reinforcedSBTACSR730mm2messengerwireintheKansaidistrict.Intermsofthenumberofmessengerwires,theone-wiretypeismoreusefulasitinvolvesasmallernumberofparts,andcopperisbetterasthematerialforthewirethanaluminumsinceitdoesnotrequireconnectionwithdifferentmetals.Therefore,wepromotedthisresearchforthepurposeofdevelopingafeedermessengerwiretypeoverheadcontactlinethathasonlyonecoppermessengerwiretorealizetheadvantagesofthetwosystems.Inordertodeterminewhatwiressuitthenewoverheadcontactline,wechoseanarrow-gaugelineinTokyoasatestsite,studiedwhetherelectricalandmechanicalcharacteristicsofwiressatisfythestandardvalues,andexaminedthecurrentcollectingcharacteristicsofvarioustypesofwiresthroughsimulation.Asaresult,itwasprovedthatthePH730mm2messengerwirewasthemostappropriateintheovercrowdedrailwaysectionsinTokyo.Basedonthisresult,weactuallyconstructedaPH730mm2messengerwireandinvestigateditscurrentcollectingcharacteristicsbyusingcurrentcollectiontestingequipmenttofindthatstandardvalueswereallsatisfiedatthespeedof160km/h.Itwasalsoprovedthatthiswiretypecouldbeusedforoperationatspeedsupto160km/h.2.ExaminationoftheoptimumwiresTable1liststhewiresexaminedascandidatesofoneonemessengerwire.Weexaminedthecurrentcapacity,wireresistance,tensilestrength,minimumhangerlengthandcurrentcollectingcharacteristics,todeterminetheapplicabilityTable1Dimensionsofwire2.1CurrentcapacityWeexaminedwhetherthewiretemperatureisbelowtheallowablelimitattheconditionsinTable2.Theallowabletemperatureis90℃fortheharddrawncopperstrandedconductor(PH)and150℃forthethermalproofharddrawncopperstrandedconductor(THDC).Figure1showsthewiretemperatureriseswhenacurrentof855A,whichisthemaximumvalueforwiresusedinTokyo,flowsfor3,600seconds.Theshadedportionrepresentsthesurroundingtemperatureof35℃,Table2ConditionsoftemperaturecalculationFig.1WiretemperaturerisesandtheportionofslashmarkthetemperaturerisesbytheJouleheat.TherearenowiresofTHDCorPHthatshowatemperatureriseovertheallowablelimitunderthiscondition.2.2WireresistanceToevaluatethewireresistance,wecomparedseveralkindsofmessengerswithtwoPH356mm2messengerwirescurrentlyusedonthenarrow-gaugelinesinTokyo.InFig.2,theslash...
