英文原文BoomtimeAhealthymarketmeansthatundergroundtruckandLHDmarkersareenjoyinghighorderlevels,heLHDsector,severalnewmodelsarealreadyonthemarketfromfirmsincludingEJC,Fermel,RhamEquipmentandSchopf(WMEOct&Nov2004),whileAtlasCopcointendstolaunchatleastonenewdesignin2005possiblyanSt14.ButitisthetrucksectorthatisthemostactiverightnowwithrenewedemphasisonpowertoweightratiosrightthroughthepayloadrangeThelatestmodelsaretakingadvantageofadvancesindieseltechnologybyfittingmorepowerfulenginesandallowingbetterspeedsonsteepramphauls.Theimpactofthisissignificant,ashigherspeedsmeanlowercycletimesandoffermajorgainsinproductivity,evenallowingreductionsinfleetsizes.Atthetopofthepayloadscalecompetitionisnowparticularlyfierce.SandvikTamrockiscertainlypushingtheboundarieswithitsToro60,athreeaxletruckwitharigidchassisanda60tonnecapacity.ThisCummins-poweredtruckoffersagoodpowertoweightratioandapayloadadvantageoverCaterpillarsAD55andatlasCoposMT5010thatSandvikTamrocksaysshouldallowminestotrimfleetsize,especiallyoverlongerramphauls.sandvikTamrockexpectstheToro60totakebacksomeofthemarketclaimedbyCatssuccessfulAD55,withits55tonnepayload.HoweverAtlasCopcoisfightingbackagainstbothCaterpillarandSandviktamrockwithyetanotherupgradetoitsMT5010truck,providingapowerincreasefrom488-597kw/650-800hp.ThenewCumminsQsk19dieselbooststheMT5010spowertoweightratiofrom5.27-6.5kw/tonne,allowingittoreclaimgroundovertheAD55andToro60,despitetheirlargerpayload.AtlseCopcoalsosaysthatdrivelineproblemswhichafflictedearliertruckdesignshavelongsincebeeneliminated.ThecompanypointsoutthatMT5010isasuccessfuldesignwithunitsoperatingIAustraliarecordingspeedsof14kphon1:10ramps,despitehaving23,000hoursontheclock.Evaluatingwhichofthesethreetrucksoffersthehighestproductivitycouldonlybeachievedbydetailedstudy(andperhapsrequiretesting),possiblywithadifferentresultdependingonthenatureofthespecificminingapplication.TherevisedMT5010hasahigherpowertoweightratiothaneithertheAD55ortheToro60butthesetruckshavebiggerpayloadsof55and60tonnesrespectively.Themachinethatbestsuitsagivenminingoperationmaybeduetoanumberofbasicfactorssuchashauldistanceandrampgradientaswellasventilationinfrastructure,ambienttemperatureandevenmaterialtype.Overallthoughthecustomerwillbethewinner,withthelatestlargeAtlasCopco,CaterpillarandSandvikTamrocktrucksallofferingmuchbetterproductivityandreliabilitythanwaseveravailabletothe50+tonneclassbefore.Thesamedortofpowertoweightratiogainscanbeseenfurtherdownthetruckpayloadrange.AtlasCopco,Caterpillar,Dux,EJC,MTIandZanamlegmethaveallfittedmorepowerfuldieselstotruckswithpayloadsinthe12-30tonnerange,withsimilarbenefitstothoseseenatthetopofthecapacityscale.Forexample,oneCanadianminereplaceditsearliergeneration16and17tonnerswithnewer20tonners,whichoffershorttraveltimesonramp,despitetheirincreasedpayloadandthishasresultedinasubstantialproductivitygainoverall.Thatthenewgenerationofenginesproducemorepowerfromsimilarouterdimensionsisimportant,astheygiveabetterpayload/litreoffuelburned.Howeverthecleaneremissionshaveaddedbenefits,withcostadvantagestomineventilationrequirements.Ingeneral,thenewsmall-midsizedtrucksthemselvesareexternallysimilartopreviousmodels,butarefittedwithstrongerdrivetrainsandaxlestocopewiththeadditionalpower(WMEOct2004&WMENov2004).Smalldetailchangeslikeextendedoillifeorfilterswithreplaceableelementsmakeidentifiablebenefitstoservicecosts.Whilethebasicdesignsoftheseupdatedtrucksremainssimilar,thebetterdrivelinesandnewgenerationdieselsmeanthatthemachinesrequirelessmaintenancearemorereliableandareconsiderablycheapertorun.Self-driveAutomationisstillontheagendawithregardtoLHDsandtrucks,withthemanybenefitsbeingshownatthoseminesthathavetakentheplungeandoptedforthistechnology.TheseisstillprogresstobemadewithregardtoordersbutCaterpillarandSandvilkTamrockarebothpushinghardtosignupcustomersfortheirLHD(andtruck)automationsystems,MINEGEMandAutominerespectively.AtthemomentonlyCodelcoisusingthefullAutomineautomationsystematthePipaNorteandDiabloRegimientozonesofitsEITenientecoppermineinChile.ButDeBeersandSandvikTAmrockaredevelopingasystemfortheFinschmineinSouthAfrica.AndwhileCaterpillarhasyettonotchupacommercialsaleforMINEGEM,thetechnologyisbeingusedforproductionatthenorthparkesandOlympicDamminesinAustralia.TherearealotofsimilaritiesinthewayMINEGEMandAutominework,withlaserequipmentmountedonboardtheLHDs.Thesescanthetunnelsaheadofthemachinesastheytram,pickingupchangesinthetunnelprofileandallowingthemachinetorecognizeitspositioninmilliseconds.Thelasersupdatetunnelmapscontinuouslyto,resultinginlargevolumesofdateshuttlingbackandforthconstantly.CatsMINEGEMsystemoperatesonawirelessLANinfrastructurewithan11Mbpscapacity.SandvikTAmrocksAutominesystemrequiressimilarbroadbandcommunicationalcapabilities.BothMINEGEMandAutominearecontrolledbyconventionalandreadilyavailablecomputinghardware,whileagooddealofthecomponentsisstandardoff-the-shelfitemsselectedfortheirabilitytocopewiththetoughminingcycle.Withthesetechnologies,oneoperatorcansupervisetherunningofuptothreeLHDsthatrunmoreorlessautonomously,withtheonlymanualinputbeingforthebucketloadingpartoftheiroperatingcycle.CaterpilliarsMINEGEMisapackagebuiltupofseverallayersandthisallowscustomerstoselecttheseparatecomponentstheyrequire.ThetacticallayerofMINEGEMprovidesautomaticsteeringforanLHDandpreventsitfromcollidingwiththewallsofthetunneloragainstothervehicles.Theoperatorfillsthebucketandselectsforwardorreverse,withthesystemprovidingautomatedtrammingandbucketdumping.ThestrategiclayerismorecomplexasthisintegratestheoperationofuptothreeLHDs,overseestheiroperationandhashigherlevelplanningcapabilities.Itisthestrategiclayerthatisinchareoftrafficcontrolfunctions,sothatmultiplecyclescanbescriptedforblendingoresfromdifferentdrawpointsforinstance,withtheoverallbenefitofincreasingproductionefficiency.Safetyisimprovedastheoperatorscanbesituatedawayfromwherethemachinesarerunning(theydontevenhavetobeinthemineatallandintheory,couldbesittinginanofficeontheothersideoftheworld).Moreover,themachinesrequirelessmaintenanceandhavelowerrunningcostsasgearchangesaremadeatoptimumtimes,enginesarenotover-revved,thereislesswheel-spinandtheriskfromcollisionswithtunnelwallsofothermachinesisallbuteliminated.However,thecompleteAutomineandMINEGEMtechnologiesarenotinexpensiveandsuitapplicationsinpurpose-builtmineareas(orevenmines).Theautomatedequipmentrunsinpartsoftheminethatareseparatedfromotheroperationsandwithpersonnelaccesscarefullycontrolled.Therearehowevercomparativelyfewlarge(and/ornew)mineswiththesortofblockcavingorsublevelcavingapplicationsthatbestsuitthissophisticatedfullautomationtechnologyandcanjustifytheinvestment.Asaresult,CaterpilliarandSandvikTamrock(separately)identifiedaneedforlesssophisticatedsystemsthatoffermanyofthesameoperatingbenefits,whilebeingsubstantiallylesscostly.ByoptingforjustthetacticallayerofMINEGEM(calledCo-Pilot),aminingfirmcanintroduceaneffectiveandcomparativelylow-costtechnologyforsingleLHDautomation.AndCO-Pilotcomeswithamanualover-ride,allowingittobeusedasaconventionalremotecontrolif/whenrequired.Inthisrespect,SandvikTamrockhasabroadlysimilarproductintheshapeofitsAutomatesystem,whichisalsodesignedforsingleLHDautomateandhasequivalentcontrolspecifications.WithAutomationorCo-Pilot,minescanintroducesingleLHDautomationintoapplicationswhereconventionalremotecontrolsystemsareusedatpresent.Theadvantageofthisisthatsinglemachinescanbenefitfromtheautomatedtramming,withouttheexpenseofthecompletemachineautomationpackage(ortheinherentchangestoinfrastructureandminelayout).BothCaterpilliarandSandvikTamrockpointoutthatthistechnologyhashugepotentialwithfirmsusingconventionalremotecontrolandwillbeofparticularbenefitatmineswithhighincidencesLHDcollisiondamage.And,asanyonewhohaseveroperatedaradio-controlledcarcanattest,itcanbedifficulttojudgedistancesbetweenamovingmachineanditssurroundingsfromadistance.Thesingleautomationequipmentwilltakeawaythisriskofcollisionsandmakesubstantialreductionsinmachinedowntimeandrepairs,aswellasboostingproductivity.AstudycommissionedbyCaterpillarfromAustralianbodySTEMshowsthatreplacingconventi