ANSI A14.3-2000(梯子)

ANSIStandardA14.3-2000Ladders–Fixed–SafetyRequirementsScopeandApplication:Thisstandardprescribesminimumrequirementsforthedesign,construction,anduseoffixedladders,andsetsforthrequirementsforcages,wells,andladdersafetysystemsusedwithfixedladdersinordertominimizepersonalinjuries.Allpartsandaccessoriesnecessaryforasafeandefficientladdershallbeconsideredintegralpartsofthedesign.Themethodsemployedtoensurecompliancewiththisstandardshallbedeterminedbytheproperregulatoryoradministrativeauthority.•Pitch:Thisstandardcoversfixedladderswithinthepitchrangeof60to90degreesfromthehorizontal.°PreferredPitch:Thepreferredpitchoffixedladdersshallbeconsideredtobewithintherangeof75to90degreesfromthehorizontal.°SubstandardPitch:Fixedladdersshallbeconsideredsubstandardiftheyareinstalledwithinthesubstandardpitchrangeof60to75degreesfromthehorizontal.°PitchGreaterThan90Degrees:Laddershavingapitchinexcessof90degreesfromthehorizontalshallnotbepermitted.•Exceptions:Thisstandardisintendedforapplicationtothetypesofstructuresdepictedanddescribedinthestandard(i.e.buildings,wells,andshafts).Itsetsforththecriteria(whatisneeded)necessarytobuildafixedladderinacertainwayandmanner(howtobuild).Thestandarddoesnotcontemplatespecialorunique(astowhereandwhen)applicationsoftherequirementsoracombinationofrequirementsmayapplyuniversally.Thisstandardestablishesrequirementsforfixedladdersinordertopromoteagreaterdegreeofstandardization.Incaseswheredifficultyisencounteredincomplyingwiththestandard,orwheretherearespecialserviceconditions,itisexpectedthattheadministrativeauthoritywillgrantexceptionsfromtheliteralrequirementsofthestandard,orwillpermittheuseofalternativedesignsorfeatures,ifequivalentsafetyistherebysecured.Theword“equivalent”inthisstandardshallbeinterpretedtomeanalternativedesign,feature,construction,connection,ormaterialprovidingequalperformance.Purpose:Thepurposeofthisstandardistoprovidesafetyforlife,limb,andpropertybyestablishingminimumstandardsforthedesignaninstallationoffixedladders.Definitions:•Cage-Abarrier,whichmaybereferredtoasacageguardorbasketguardthatisanenclosuremountedonthesiderailsofthefixedladderorfastenedtothestructuretoenclosetheclimbingspaceoftheladderinordertosafeguardtheemployeeclimbingtheladder.•Carrier-Thetrackofaladdersystemconsistingofflexiblecableorrigidrail,whichissecuredtotheladderorstructurebymountings.•Connector-Acomponentusedtoconnectanddisconnectbetweentheharnessandtheladdersafetysleeve(examplesincludesnaphooksandcarabiners).•Fastening-Meansattachingaladdertoastructure,buildingorequipmentusingapositivemeanssuchasbolt,weldorothertypeoffasteners.•FixedLadder-Aladderpermanentlyattachedtoastructure.•Harness,FullBody-Acomponentwithadesignofstrapswhichisfastenedaboutthepersoninamannersoastocontainthetorsoanddistributethefallarrestforcesoveratleasttheupperthighs,pelvis,chestandshoulders.(Over)(cont’d)•LadderSafetySystem-Anassemblyofcomponentswhosefunctionistoarrestthefallofauser,includingthecarrieranditsassociatedattachmentelements(brackets,fasteners,etc.)safetysleeve,fullbodyharnessandconnectors,whereinthecarrierispermanentlyattachedtotheclimbingfaceoftheladderorimmediatelyadjacenttothestructure.•Mounting-Ameansforattachingacageoraladdersafetysystemtoaladder.•Pitch-Theincluded(acute)anglebetweenthehorizontalandtheladder,whichismeasuredontheoppositesideoftheladderfromtheclimbingside.ThepitchisusuallyexpressedasH/L,whichisthehorizontaldistance,H,fromthebaseoftheladdertothesupportingsurfacedividedbytheworkinglength,L,oftheladder.•Platform-Alandingsurfacethatisusedasaworkingorstandinglocation.•SafetySleeve-Thepartofaladdersafetysystemconsistingofthemovingcomponentwithlockingmechanismthattravelsonthecarrierandmakesaconnectionbetweenthecarrierandthefullbodyharness.•Well(Shaft)-Awalledenclosurearoundafixedladderthatprovidesthepersonclimbingtheladderwiththesameprotectionasacage.Thisstandardalsodescribes:GeneralDesignCriteriaDesignDetailsforFixedLaddersDesignDetailsforCages,WellsandPlatformsLadderSafetySystemProtectiveFinishesMaintenanceandUseofLaddersNote:SeenextpageforfixedladderillustrationThisbulletincontainsasummaryofexcerptstakenfromtheStandard,forgeneralinformationpurposesonly.ThisbulletinisnotreflectiveofthecompleterequirementsthattheStandardprescribes.RefertoANSIA14.3SafetyRequirementsforFixedLadders.“A”Requireddistance3.5feet(1.07m)excludingarch.“B”Minimum7inches(18cm)“C”Maximum12inches(30cm)betweencentres,allrungs.“D”Fromcentreofrung27inches-30inches(68.5cm-76.25cm)andshallnotbelessthan27inches(68.5cm)inwidth“E”Minimum16inches(40cm)clearwidthbetweensiderailsFMaximum12inches(30cm)“G”Hoopingshallbeginataheightof8feet(2.44m)fromgradeHLockableblankdoorstoextendhighenoughtopreventunauthorizedaccessIMaximumspacingbetweenhoops4feet(1.22m)JBandsshallbespacedamaximum40degreesoncentrearoundthecircumferenceofthecage.Thiswillresultinamaximumspacingof9.5inches(24cm)Thesurfaceoftheparapetbetweenthehandrailsoftheladdershallbecoveredbyexpandedmetaldeckinghavingaminimumwidthof2ft(O.6m),orothernon-skidsurfaceacceptabletotheinspectingauth