553OccupationalSafetyandHealthAdmin.,Labor§1910.179distanceisgreaterthanthedistancefromthefrontfaceoftheforks.Calculatingthemaximumallowableload-momentusingtheload-centerdistancealwaysprovidesalowerload-momentthanthetruckwasdesignedtohandle.Whenhandlingunusualloads,suchasthosethatarelargerthan48incheslong(thecenterofgravityisgreaterthan24inches)orthathaveanoffsetcenterofgrav-ity,etc.,amaximumallowableload-momentshouldbecalculatedandusedtodeterminewhetheraloadcanbesafelyhandled.Forex-ample,ifanoperatorisoperatinga3000poundcapacitytruck(witha24-inchloadcenter),themaximumallowableload-mo-mentis72,000inch-pounds(3,000times24).Ifaloadis60incheslong(30-inchloadcenter),thenthemaximumthatthisloadcanweighis2,400pounds(72,000dividedby30).A–6.LateralStability.A–6.1.Thevehicle’slateralstabilityisde-terminedbythelineofaction’sposition(averticallinethatpassesthroughthecom-binedvehicle’sandload’scenterofgravity)relativetothestabilitytriangle.Whenthevehicleisnotloaded,thetruck’scenterofgravitylocationistheonlyfactortobecon-sideredindeterminingthetruck’sstability.Aslongasthelineofactionofthecombinedvehicle’sandload’scenterofgravityfallswithinthestabilitytriangle,thetruckisstableandwillnottipover.However,ifthelineofactionfallsoutsidethestabilitytri-angle,thetruckisnotstableandmaytipover.RefertoFigure2.A–6.2.Factorsthataffectthevehicle’slat-eralstabilityincludetheload’splacementonthetruck,theheightoftheloadabovethesurfaceonwhichthevehicleisoper-ating,andthevehicle’sdegreeoflean.A–7.DynamicStability.A–7.1.Uptothispoint,thestabilityofapoweredindustrialtruckhasbeendiscussedwithoutconsideringthedynamicforcesthatresultwhenthevehicleandloadareputintomotion.Theweight’stransferandtheresult-antshiftinthecenterofgravityduetothedynamicforcescreatedwhenthemachineismoving,braking,cornering,lifting,tilting,andloweringloads,etc.,areimportantsta-bilityconsiderations.A–7.2.Whendeterminingwhetheraloadcanbesafelyhandled,theoperatorshouldexerciseextracautionwhenhandlingloadsthatcausethevehicletoapproachitsmax-imumdesigncharacteristics.Forexample,ifanoperatormusthandleamaximumload,theloadshouldbecarriedatthelowestposi-tionpossible,thetruckshouldbeacceler-atedslowlyandevenly,andtheforksshouldbetiltedforwardcautiously.However,nopreciserulescanbeformulatedtocoveralloftheseeventualities.[39FR23502,June27,1974,asamendedat40FR23073,May28,1975;43FR49749,Oct.24,1978;49FR5322,Feb.10,1984;53FR12122,Apr.12,1988;55FR32015,Aug6,1990;61FR9239,Mar.7,1996;63FR66270,Dec.1,1998;68FR32638,June2,2003;71FR16672,Apr.3,2006]§1910.179Overheadandgantrycranes.(a)Definitionsapplicabletothissec-tion.(1)Acraneisamachineforliftingandloweringaloadandmovingithori-zontally,withthehoistingmechanismanintegralpartofthemachine.Craneswhetherfixedormobilearedrivenmanuallyorbypower.(2)Anautomaticcraneisacranewhichwhenactivatedoperatesthroughapresetcycleorcycles.(3)Acab-operatedcraneisacranecontrolledbyanoperatorinacablo-catedonthebridgeortrolley.(4)Cantilevergantrycranemeansagantryorsemigantrycraneinwhichthebridgegirdersortrussesextendtransverselybeyondthecranerunwayononeorbothsides.(5)Floor-operatedcranemeansacranewhichispendantornonconductiveropecontrolledbyanoperatoronthefloororanindependentplatform.(6)Gantrycranemeansacranesimi-lartoanoverheadcraneexceptthatthebridgeforcarryingthetrolleyortrolleysisrigidlysupportedontwoormor...
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