User guide
Toavoidanunintendeddisengagementofconnectors,useonlycompatibleconnectorswhenconnectingtotheanchorage.Ensureallconnectorscloseand
locksecurely.SeeFigure13inAppendixB.
NOTE:OSHA1926.502and1910.66requiresthatanchorsforaPFASbeabletoholdatleast5,000poundsofweightperpersonormaintainasafetyfactor
ofatleasttwo(twicetheimpactload)underthesupervisionofaqualifiedperson.AlsoensuretheanchorpointwillprovidesufficientMRFC.
4.3MinimumRequiredFallClearance:TheMRFCistheminimumdistanceauserneedsbetweenhimselfandthenearestobstruction(orground)below
thewalking/workingsurfacetoavoidseriousinjuryordeathincaseofafallevent.TheuserofthisequipmentmustdeterminetheMRFCforunits
discussedinthismanualtoensureadequateclearanceexistsinthefallpath.Variablesdiscussedinthismanualincludetheheightoftheanchorpoint
relativetotheuser’sFBHD‐ring,i.e.,overheadornon‐overheadanchoragecondition,
plusswingfall,andhowanexpandedworkzoneaffectsthese
variables.
4.4Overhead(AbovetheD‐ring)AnchorageCondition:Inanoverheadanchoragecondition,theSRDisinstalledanywhereintheallowableattachment
area,whichrangesfromdirectlyabovetheusertoaslowastheleveloftheFBHD‐ring,asshowninFigure3AinAppendix
A.Theoverheadcondition
MRFChasthreemetrics,labeledA,B,andC,measuredfromthewalking/workingsurface.Thesumtotalofthesemetrics,labeledD,istheMRFC.
A=SRDdecelerationdistance
B=D‐ringshiftandharnes
sstretch
C=Safetyfactor
TheMRFCforanoverheadanchorageiscalculatedasA+B+C=D.
4.5Non‐Overhead(BelowtheD‐Ring)AnchorageCondition:Inanon‐overheadanchoragecondition,theanchorpointislevelwiththeFBHdorsalD‐ring,
orupto2'belowit,asshowninFigure3BinAppendixA.TheMRFCforabelowtheD‐ringconditionhasfiveme
trics,labeledA,B,C,D,andE,andare
measuredfromthewalking/workingsurface.Thesumtotalofthesemetrics,labeledF,istheMRFC.
A=AnchorageDi
stancebelowDorsalD‐ring
B=SRDDecelerationDistance
C=AdditionalDecelerationDistanceduetoBelowD‐ringattachment
D=D‐ringshiftandharnessstretch
E=Safetyfactor
TheMRFCforananchoragebelowtheD‐ringiscalculatedasA+B+C+D+E=F.Beawar
ethatiftheuseriskneelingorcrouchingwhileperformingwork,add
uptoanadditional3feettothetotalMRFC.
4.6SwingFall:Aswingfalloccurswhentheworkermoveslaterallyoutfromundertheanchorageandcreatesanexpandedworkzonecondition.See
Figure4inAppendixA.Ifafalleventoccurs,theworkerwouldswingbacktowardtheanchorage.Theswingingactiongeneratesconsiderableforce,andif
theworkerstrikesanobstructionormakescontactwiththelowerlevelortheground,thisforcecouldcausesevereinjuryordeath.
OverheadAnchorageandSwingFall:Foreachfoottheusermoveslaterallyinanydirectionawayfromtheanchorage,theworkzoneexpandsandswing
fallforcesincrease.ThisincreasedforcerequiresadditionalMRFCdistance.SeeChart1inAppendixAforinstructionsoncalculatingadditionalfall
clearancedistancecausedbyexpandedworkzoneswingfallconditions.
Non‐OverheadAnchorageandSwingFall:Aworkzoneexpandedbylateralmovementwillincreaseswingfallhazards,especiallyinanon‐overhead
anchoragecondition.Chart1depictstherelationshipbetweenthedistanceoftheanchorinfeetbelowtheFBHD‐ringandtheexpandedworkzone,
measuredinfeet.Theloweranchorpointofanon‐overheadanchorage,combinedwiththelateraldistancefromtheanchoragemeasuredinfeet,means
theuserwillfallfurther,placingtheuseratextremeriskofsevereinjuryordeathincaseofcontactwithanobstruction,thelowerleve
l,ortheground.The
moretheworkzoneexpands,andthelowertheanchorageis,themoretheriskincreases.
WARNING
AnexpandedworkzonecombinedwithanSRDusedinanon‐overhead(belowtheD‐ring)conditionisextremelyhazardous.
DONOTattachtheunittoanypointmorethan2feetbelowtheleveloftheFBHD‐ring.
4.7LockingSpeed:TheSRDutilizesacentrifugallockingmechanism.Thelockingfunctionrequiresacertainpayoutrateduringafalleventtofunction
correctly.Ifafalloccurs,apawlmechanismisengaged,whichappliesabrake,slowingandarrestingthefall.Certainsituations,confinedorcramped
spaces,shiftingfootingsuchassand,gravel,grain,oraslopedsurfacemaynotallowthelifelinetoreachsufficientspeedtoactivatethelockmechanism.A
clearpathisrequiredtoassurepositivelockingoftheSRD.
4.8InstallationandUseoftheSRD:TheSRD
maybeinstalledandusedasasingleunit,orasatwin.
4.8.1SingleSRD:OneSRDwithtwoorientationoptions;
Housingattachedtotheharness:TheSRDhousingendisinstalledtothedorsalD‐ringofaFBHandthelegendattachedtoananchorage.Theanchorage
mayrangefromoverhead,toaslowas2'belowthedorsalD‐ring.ReferbacktoFigure2AinAppendixA.
ToinstalltheSRDontheharnessseeFigure5AinAppendixA.Followthesesteps:
1. Dontheharnessinaccordancewiththeharnessmanufacturer’sinstructions.
2. InsertthenoseendofanANSIcompatibledouble‐lockingcarabinerthroughtheSRDhousingswiveleye.
3. AttachthecarabinertothedorsalD‐ringoftheFBH.Ensurethecarabinerisorientedwiththelockopeningupandwilltaketheloadalongitsmajor
axis.Visuallyensurethecarabinerclosesandlockssecurely.
4. Connectthelegendconnectortoanapproved,suitableanchorthatmeetsworkzonerequirements.
TheSRDwillpayoutandretractsmoothlytomaintainatautlineduringnormalmovement.Workasdirectlyundertheanchoraspossible.Ifne
cessary,
attachthelegendconnectortoalowerlevelanchorage,upto2ft.belowtheuser’sharnessD‐ring.Beawarethataloweranchorageincreasestheriskof
injuryduetoswingfall.Additionalfallclearanceisrequired.
DONOTusearebarhookoranylarge‐throatsnaphookorlarg
ecarabinertoinstallthehousingontheFBH,asthiscouldcauseasideloadandcreatean
unintentionaldisengagement.
Housingattachedtotheanchorage:Asingle‐legSRDwiththehousingendattachedtoananchorageandthelegendconnectedtotheuser’sFBH.The
anchoragemayrangefromoverhead,toaslowas2'belowthedorsalD‐ring.ReferbacktoFigure2B.ConnectthelegendconnectortothedorsalD‐ring.
Toattachthehousingtoananchorage,seeFigure5Bandfollowthesesteps;
1. Dontheharnessinaccordancewiththeharnessmanufacturer’sinstructions.
2. Insert
thenoseendofanANSIcompatibledouble‐lockingcarabinerthroughtheSRDhousingswiveleye.
3. Attachthiscarabinertotheanchorpoint.Ensurethecarabinerisorientedwiththelockopeningupandwilltaketheloadalongitsmajoraxis.Visually
ensurethecarabinerclosesandlockscompletely.
4. Connectthele
gendconnectortothedorsalD‐ringoftheFBH.Visuallyensuretheconnectorclosesandlockscompletely.
4