alrc roll-cage regulations 1 roll-cages · 2018. 3. 14. · the roll-cage field. 1.2.10. a...

116 Association of Land Rover Clubs 2017 Handbook Association of Land Rover Clubs 2017 Handbook 117

1 Roll-Cages1.1. Introduction1.1.1. CrossCountryVehiclesarelikelytooverturnduringafiercelycompetitiveevent.There

is,therefore,abasicrequirementtoprotectthedriverfrominjuryshouldthishappenTheroll-cageshouldbeabletowithstandreasonableimpactwithoutdeformation,unlikedesignsusedinotherbranchesofmotorsportwhereacrushable,energyabsorbingstructureworkinginconjunctionwiththemonocoquestructureofthevehicleisused.

1.1.2. When is a roll-cage needed? Event Open / Soft top vehicle Hard-top vehicle RTV Notapplicable NO CCVT CAGE(withcentrebar) CAGE

CompSafari,TimedTrial,TeamRecovery,PointtoPoint,seeMSAYearbookforregulations.

1.2. General Points and Advice1.2.1. Ifyouarebuyingasecond-handroll-cagefroma‘friend’,examineityourself,don’trelyon

hisassurancethatit“hasbeenoverthousandsoftimesandisstillallright”.Rollingovergentlyatatrialisdifferentfromthebone-breakingjarsofaCompetitiveSafariroll.Your‘friend’maynothaveevenstressedthecageifthevehiclehasonlyfallenonitsside.

1.2.2. IsthedesigntoanALRCpattern?Ifnot,youwillnotbeallowedtocompeteinALRCeventsthat require a roll-cage.

1.2.3. CHECK,andcheckcarefully,scrape/wirebrushpaintfromallweldsandensurethattheyareweldsandnotjustblobsofmetalgroundawaytolookreasonablewithalayerofpaintontop.

1.2.4. Ifthemetalispitted,thiswillhavebeencausedbyrust,ifitispittedontheoutsidethinkwhatitwillbelikeontheinside.Youdonotwantthatcage.

1.2.5. Asecond-handcagecanbeaverydangerousthingtobuywithoutfullyknowingitshistory.Ifasecond-handcarbreaksdown,it’sunlikelytoharmyou,ifasecond-handroll-cagebreaksdownitwilldosobecausethereisnearly2tonsontopofitwithyouasthemeatinthe sandwich; not very healthy.

1.2.6. Makingaroll-cageyourselfcanalsobeaverytryingexperiencewithatubebenderbeingasimplelookingdevicewhichisnotsosimpletouse.Inexperiencewithoneleadstobendsnotbeinginthesameplane,notallowingforthe‘spring’inthematerialandgettingthebendsinthewrongplace;allgoodfun!

1.2.7. Don’tforget,aswell,whenweldingitupaftercarefulbending/cuttingthetubewilldistort,expertweldingwillminimisedistortionandknowledgebuiltupinthefabricationtradewillassist.Withoutit,youareinfordisappointment.

1.2.8. Ifusinggalvanisedtubeensurethatyougrindthezinccoatingofffirst.Failuretodosowillresultinpoorweldsandbreathingproblemscausedbythetoxicgassesgivenoffbytheweldingprocess.

1.2.9. Somedangersof‘home’buildinghavebeenhighlightedashavesomeofthesecond-handbuyingpitfalls.Withcaretheycanbeavoided,seekexpertadvicebeforesteppingoutintotheroll-cagefield.

1.2.10. Aroll-cageisprobablytheseconddearestthingyouwillhavetogetwhencompetingincrosscountryevents.Indeed,itmayevenbedearerthanthevehicleyoucompetein.

1.2.11. It is well worth buying one that is sound and solid. If you have any doubts about the ability ofthemanufacturer,theanswerissimple,don’tgetit.Itmaybetheadviceis“don’tmakeityourself”.Youknowyourcapabilities,itisyourlifeyouaredealingwithandthatofyournavigator.Pleasedonottreatitlightly.

1.2.12. Ifyoucan’tmaketheroll-cageyourselfandno-oneyouknowpersonallycanmakeoneforyou,thenyourbestbetwillbetobuyonefromoneofthemanycompaniesmaking,sellingand/orinstallingroll-cagesbuilttoALRCspecifications.It’sstillyourresponsibilityto

ALRC Roll-Cage RegulationsNOTE:RoadTaxedVehicleTrialsvehiclesdonotrequireroll-overprotection.TheseregulationsrelatetoCrossCountryVehiclestrialsvehiclesonly.Forallotherclasses,seetheMSA2017

YearbookSectionK,Safety.Vehicles with a chassis should follow these regulations;

monocoquevehiclesshouldfollowMSAroll-cagedesigns.Eachparagraphanddrawingisidentifiedbyanumber asanaidtoidentificationandsubsequentamendment.

Ifyouneedanyfurtherclarification,pleasecontactanymembersofthe ScrutineeringandOff-RoadCommitteemembers;listonpage4.

INDEX of TOPICS

1 Introduction to Roll-Cages,.

2. Design.

3. MaterialsandComponents.

4. Configurations.

5. Fronthoopmountingandattachmentmethods.

5.3 Fabricatedbulkheadsandvariousmethodsofboltingorweldingthefronthooptoa

bulkheadfabricatedfrombox-section.

6. InternalMainhoopwithexternalFrontHoop.

7. FrontHoopDesignsandAttachmentstoChassis.

7.6. Integratedfronthoop/bulkheadassembly.

7.7. RangeRover/DiscoverymountingtofrontOutrigger.

7.8. FrontHoopMountingtoOutriggeronSI-III&90/110etc.

8. MainHoops.

8.1. StandardDesign.

8.2. MethodsofSecuringRollCagestoChassis.

8.3. StandardShapeHoopMountingonto“A”-FrameCross-Member.

8.4. MainHoopDesignandInstallationforRangeRover/DiscoveryandotherLong

WheelbaseStationWagons.

8.5. Methodsofattachingthehooptothebox-beam.

8.6. Methodsofattachingthebox-beamtothechassis.

8.7. Roll-cageson101”WheelbaseForwardControlLandRovers.

9. Rear Bracing Bars.

10. Seatbelts.

11. Joints various.

12. ExemptionforForeignRegistered&ResidentVehicles.


tube.Bracingbars,bothrearanddiagonal,maybemadedetachableorjointedasspecifiedlater.

3.3. Materialspittedwithrustarenotpermitted.3.4. Hoopcornersmustnotbeseparatesectionsandclampsorangledcornersareprohibited.

Cornerswherethetubehasflattenedorisshowingsignsof‘crimping’arenotallowed,neitheraretubeendsflattenedorcrimpedforeaseofwelding.Theratioofminimumdiametertomajordiameteris0.9orgreater.Tubeendsshouldbecorrectlyshapedtofitthebartheyarejoinedto.Bendradiusmustbeatleastthreetimesthetubediameter.

3.5. Anyplugsinsertedintothetubingforthepurposesofpreventingcrushingorinthemakingofjoints(seelater)willbemadefromEN8orequivalent(orbetter)material.

Belowisthetableshowingthedimensionsofpermittedmaterials:3.6. (TABLE) BS1387* CDSItem Imperial size

(inch)Metric

size (mm)Metric

size (mm)Practical

Metric sizeDiameterforalltubeincludingbracing/supportingbars.

1 7/8”o/d 48 to 48.8 o/d

47.6o/d -

Tubewallthickness 1/8” 3.2 2.5 -Roll-barbase-platethickness 1/8” 3.2 3.2 -Anyotherplate/bracketthickness. 1/4” 6.4 - 6Mountingboltsizes(HTS) 3/8” 9.6 - 10*1387tubeissoldbyit’snominalbore,whichisknownas40mm/1½”.

3.7. Alloftheaboveareminimumsizesandmaybeexceeded.3.8. Welding3.8.1. Welding should be carried out to the highest standards.3.8.2. Weldsshouldbecleaned,butnotgroundorfiledaftercompletion.3.9. InspectionHoles3.9.1. Aninspectionhole3/16”/5mmdiametermustbedrilledthrougheverysectionoftubeused.

Itshouldbedrilledinastraightlengthatleast100mm/4”fromabendandinapositionsoastominimisewaterentryandwhereitcanbeseeneasily.

3.9.2. Theonlypermitteddrilledholeisaholeof3/16”diameterforinspectionpurposesonrollcagesandfabricatedbulkheadsunlesscurrentregulationsallow.GrandfatherrightscanbegiventovehicleswithexistingholesfortheroofpanelsbutthesevehiclescanonlybeusedforCCVTandnotspeedevents.Allnewbuildsmustcomplywiththerule.Vehicleswithdrilledholesforwingsorattachmentsfordoors-Withrelationtobulkheadswherethefrontcageisabulkheaditcanbeuseduntilthenextre-logbookingwhenitneedstobealteredto a bulkhead with no holes.

3.10.NutsandBolts3.10.1. Allnutsandboltsusedinsecuringaroll-cageshouldbemadefromhightensilesteel.3.10.2. Platedorcorrosionprotected/treatednutsandboltsarerecommended.Wherepossible

useplatednutsandbolts,thebestqualityhightensilesteelboltwillstillrustunlesstreated.Thereisnosubstituteforgettingthemwithafinishthatwillnotrust;selfcolouredorblackonescomewithonlyacoveringoflightoilthatwillsoongoandthecorrosionproblemsbegin.

3.10.3. Allhightensileboltsmusthaveappropriatemarkingsonthehead;ifithasonlymanufacturer’smarkingsorithasaplainheaddonotuseit.Themarkingscanconsistofeitherletters(UNC,UNFandWhit.threadedbolts)ornumbers(MetricorISOMetric).Thelettertolookforis‘S’orahigherletterorthenumber8.8orhigher.(Forthetechnicallyminded,the8.8designationistwoseparatenumbers.Thefirst‘8’isthetensilestrength,i.e.theloadatwhichthematerialbeginstofail,giveninunitsof100MPaorMN/mm2,giving800MN/mm2or800,000,000N/m2.Convertthistokgbydividingbygravity(9.81m/

ensurethatitreallydoescomplywiththefollowingregulations.1.2.13. Neverforgetthatthebasicpurposeofaroll-cageistoprotectthedriver/passengershould

thevehiclerolloverorhaveaseriousaccident.Nomatterwhatthe‘car’rallymanmaysay,duetothenatureofthegroundthatwecrossthissportispotentiallythemostdangerous,theforcesinvolvedina30mphLandRoverrollroughlyequatetorollingat100mphinaFormulaOnecar(ifonerelatespurelytoweightdifferences).MoreifoneconsidersthataFormulaOnevehiclenormallyscrapesacrossflatground,CCVcompetitorsdonot.

1.2.14. Roll-cagesmustbeabletowithstandthesethreeloadssimultaneously:1.5glateral,5.5gfore and aft, 7.5g vertical.

2. Design2.1. Thedrawingbelowgivesaverysimplegeneralideaofthepositionandsizeofabasic

roll-cage.

2.3. Themainhoopandthewindscreenorfronthoopwillrunacrossthewidthofthevehicle.Itsheightwillbedeterminedbytherequirementfortheretobeadistanceofatleast50mm/2”fromthetopofthedriver’shead(whencrash-helmetedasapplicable)tothetopofthebarandbeaswideaspossiblewithinthevehicle’sbody.

2.4. Themainhoop,behindthedriver,shouldbevertical.Itshouldbeascloseaspossibletothebackofthedriver’sseat.

3. Materials and Components.

3.1. Theminimummaterialspecificationforalltubingwillbenominal38mm/1½”boresteel“blueband”tubingtoBS1387.(Thiswillactuallybenearer42mm/15/8”)Thishasaminimumwallthicknessof3.2mm/1/8”andaminimumoutsidediameterof48.3mm/17/8”.Seetablebelowforpracticalimperialandmetricstocksizes.Tensilestrengthwillbebetween320-416N/mm2.Yieldstrengthwillbeatleast195N/mm2.Tubingwhichexceedsthisspecificationisrecommendedwheretheoutsidediameteratleastmatchestheabovetypeandaminimumnominalwallthicknessof2.5mmwherethequalityandorigincanbetraced.”

3.2. Allhoops(mainandfront)andthediagonalshalleachbemadeofonecontinuouspieceof


4. Configurations

4.2. Thesetwoplan-viewdrawingsshow:4.2.1. Alternativetypesoftubeconnectingthemainhooptothefronthoop.Straightorbentones

maybeusedsubjecttothelimitsshownonthenextpage.4.2.2. Alternativepositionsfortherearbraceswheretheyjointhemainhoop.Seedrawing

4.1.Rearbracedesign“A”maybeusedforanyeventsbutismandatoryforCompetitiveSafariandPoint-to-point.Rearbracedesign“B”maybeusedforanyeventsotherthanCompetitiveSafariandPoint-to-point,andbefittedintheareabetweenthetwopositionsshown.

4.2.3. Alternativepositionsforcentre-bar or diagonal which isrequiredforopenvehiclesonly.Iftwoormorecentrebarsarefitted,theyshouldbeevenlyspaced.

4.4. Thefeetspacing‘a’to‘c’shouldbeasfarapartaspossiblewithintheloadarea.Thesmallertheangleabcatthetop,thelesseffective are the bracing bars.

4.5. Readonformethodsofattachmenttochassis.

s2)say10,togive80,000,000kg/m2,andthendivideby104toconverttocm2whichgives8000kg/cm2or8tonnes/cm2.Thesecondpartofthedesignation‘.8’isthenusedtogenerateadecimalfractionofthefirstpart,i.e.8x0.8=6.4or640Mpa,6.4tonnes/cm2.Thisistheyieldstrength,i.e.theloadatwhichplasticdeformationofthematerialoccurs.)StainlessSteelboltsusuallyhaveatensilestrengthof5Tonnes/cm2,33tons/in2(markedA2forStainlessSteeland‘M’forthestrength)sobewarned!SomeboltsmaybemarkedinNewtonspersquarecentimetre,inwhichcasehigh-tensilemeansover80N/cm2.Donotgetconfusedwiththemanufacturer’snamecode,e.g.GKN,SN,BP,etc.Hightensileboltsmustalwaysbefittedwithhightensilenuts,andthesewillalsohaveappropriatemarkings.Usually,therewillbeamarkingontheface(nottheflat)ofthenutandthismaybeoutofsightwhenfitteddependingwhichwayupyouscrewiton.Nylocnutsareoftenplatedbutshouldstillshowthismark;youdon’thavetheoptionwhichwayupthistypeofnutgoesandthismarkwillnotbevisibleonassembly.Afigure8willequatetoagrade8specificationandmustbeusedwithagrade8bolt.Nutsmayalsohavea“clockcode”.Theremaybeadotandastroke.Withthedotatthetop(12o’clockposition)looktoseewherethestrokeis.Astrokeatthe8o’clockpositionindicatesagrade8nut.Youmustbeabletoprovetoascrutineerthatthenutsandboltsusedmeetthesespecifications.Ifindoubt,askthesupplierforachartthatshowsthemeaningofthemarkings.

3.10.4. Plainnutsmustalwayshavelocknutsortheymustbeselflockingtypes.Thereareseveraloftheserangingfrom‘Nyloc’to‘splitring’types.Alternatively,usecastellatednutsandsplitpinsortabwashers.Youmustalwaysuseawashersunderthenutsandtheseshouldbesuitableforthetypeofnut.

3.10.5. Alsoremember,asetscrewwiththethreadrunningfromtiptotheheadisnotabolt(whichhasthethreadrunningfromthetiptotheshank-approx.2/3thelengthofthebolt)andisnotdesignedtobearashearload.Theplainshankisdesignedtodothat,athreadisdesignedtousethenuton.Drilltheholestofityourbolts(orbuyyourboltstofittheholes!)anddonothaveanygapsroundthem.

3.10.6. Bolt(andothermaterial)sizesshowninthisbookaregiveninImperialandMetricsizes.Fornutsandbolts,youmaynotbeabletoget9.6mm,(3/8”),forexample-alwaysgetthenextlargest‘whole’numbersize,e.g.9.6mm=10mm.

3.10.7. Thefollowingtablemaybehelpful.

Imperial (inch) Metric (mm) Item1/8 3 Tubewallthickness

3/16 5 Bolts1/8 3 Bolts&Plates1/4 6 “

5/16 8 “3/8 10 “1/2 13 “

9/16 15 “17/8 48 Roll-cage tube2 50 “

12 305 1 foot36 915 3feet/1yard

The following information on roll-cages, outriggers, mountings, seat-belts etc. represents minimum specifications which may be added to as required.


5.3.2. Theitemshownas“bulkhead”inthefollowingdrawingsreferstoabulkheadfabricatedfrombox-sectionorroll-cagegradetube.

5. Front hoop mounting and attachment methods

5.2. Thefronthoopshouldrunacrossthewidthofthevehicleandthetoppartmustnotleanbackanyfurtherthantheangleofthewindscreen.Bendsmaybeusedontheconnectingbarsbetweenthefrontandrearhoopsbutshouldnothavemorethan4”/100mmbetween‘a’and‘b’asshownabove.Theangleofthewindscreenshouldbethatofa90/110foranySeriesorDefendervehicles(ThefronthooponanySeriesvehicleor90/110/Defendervehiclesmayleanbackbyanangleofnomorethan33ºfromthevertical)ortheactualangleonothertypes;evenifawindscreenoritspillarsarenotfitted.

5.2.1. Ifabulkheadfabricatedfromtubeandangleisused,thefronthoopmaybeweldedorboltedtothetopedgeboxmaterial.

5.2.2. Ifthefronthoopcontinuesdowntobecomeapartofthefabricatedbulkheadstructure,thenthemountingmustbeasshownin“Integratedfront-hoop/bulkheadassembly”diagram.Seepara.7.6.

5.2.3. Whereastandard/originalbulkheadisused,thefronthoopmustbeardownontothechassisorsuitablystrengthenedorfabricatedoutriggersasshowninpara.7.1.

5.3. Fabricatedbulkheadsandvariousmethodsofboltingorweldingthefronthooptoabulkheadfabricatedfrombox-section.


6.2. Ifyouneedtohavethefronthoopontheoutsideofahard-toporsoft-topwiththemainhoopinside,thefollowingdesignmayhelp.Thesquareplatesthatsandwichtheroofpanelareofstandarddesigndefinedelsewhere.Theplatesmaybelevelorangledtosuittheshapeoftheroof.Theremustbenomorethan4”/100mmbetweenthetopoftheroll-cagetoptubeandtheinsideoftheroof.Thedifferencemaybemadeupwithroundtubeasusedfortheroll-cage,orbyboxsectionatleast2”/50mmsquareby1/8”/3mmwall.Onsoft-topinstallations,themainhoopmayreplacethefirsttilt-framewithonlytheboltholesperforatingthematerial.

6.3. Thejointshownindrawing8.2.14.couldbeusedtomakeanadjustableupstand,ifinvertedfromthewayitisdrawn.

7. Front Hoop Designs and Attachments to Chassis

7.1. Thedrawing7.3.showsdetailsonhowtoattachafronthooptoexistingoutriggersortofabricated ones. Alltypesofoutrigger should beatleast4”/100mmdeepatthe chassis, but oncoil-sprungvehicles, the outriggermustbeasdeepaspossiblebutstillprovideclearancefor the front suspensionradiusarms.

7.2. Ifitisnotpossibleto bring the front hooplegstraightdown onto an existingoutrigger,themountmaybeoffsetbyupto4”/100mmahead, behind or outboard as shownbottomright of drawing 7.3.

5.3.6. Notethatthehoopalwaysrestsontopoftheangleirontofacilitateweldingandtopreventloadbeingtakenentirelyontheweld.Allboltsaretobeaminimumof3/8”/10mmhightensile steel.

5.3.9. (leftabove)Wherethetubematerialisequaltoorgreaterthan¼”/6mm,thenthehoopmaybeweldeddirectlyontop.

5.3.10. (rightabove)Wherethetubematerialislessthan¼”/6mm,thenasaddleofatleast¼”/6mmsteelmustbeusedasshown.

6. Internal Main hoop with external Front Hoop6.1. Thediagram(right)

shows the general requirementsforthefore/aft,left/right,andup/downdimensionsbetweentheoccupantsand the roll-cage.

6.2. (DRAWING.MSASectionKdrawing31)

Chin to knee


7.7. Range Rover / Discovery mounting to front Outrigger

7.7.1. MountingthefronthoopinaRangeRoverorDiscoverycanbedifficultbutthefollowing“top-hat”guidelinesmighthelp.Thisusesastandard¼”/6mmfootsittingonthefloorandboltedthroughtothe“top-hat”underneath.Theprincipleisthesameastherear-bracemountshownin9.2.3.forthe90whereabox-sectionupstandwithaflatplateontopinused.Asfarasreinforcingtheoutriggerisconcerned,add¼”/6mmplatestotheoutrigger.Theseshouldextendinwardstothechassis.Therule-bookstatesthattheyshouldbe4”/100mmdeepatthatpointbutthefrontradius-armmountsandtheshallowfront-faceoftheoutriggeritselfmakethesedimensionshardtoachieveinpractice.Theside-platesandthepartsofthe“top-hat”couldpossiblybecutasshowntosimplifymatters.Plateovertheinsideandoutsideofthe“top-hat”boxasshown.

7.5. Thedrawingaboveshowshowthe4”/100mmdepthatthechassiscanbeachieved.Thewedgemustbeatleasthalfthespanoftheoutrigger.

7.6. Integrated front hoop / bulkhead assembly

7.6.1. Inthisvariation,thefronthoopsidepiecesturninandareweldedtothesideofthechassis.Thisispermissiblewherethefronthoopformspartofanintegratedfront-hoop/bulkheadassembly.Thefronthoopisneithercutnorweldedwhereitchangesfrombeingthefronthooptobeingapartofthebulkhead.Seedrawing7.6.4.

7.6.2. Thistypeofstructureisacceptablesolongasalltheprovisionsdetailedinthedrawingareadheredto.Otherwise,box-sectionoutriggersshouldbeusedtosupporttheendsofthefronthoop.Iftheall-roundhoophasbeenfittedbutisnotpartoftheintegratedassembly,thenboxingintheexistingturned-intubeisacceptable.

7.6.3. Ifthespreaderplatesarenotpresentonthechassis or additional membersareunderthe size shown or are absent, then anoutriggermustbefitted.Thiscaneitherbebuiltuparound the turned in tube as shown using 1/8”/3mmplateorabox-sectionoutriggerfittedasshown.Don’tforgetthe¼”/6mmspreaderplateonthechassisormakethetopplateoftheoutriggerfromthisthicknessmaterial.


8.2. Methods of Securing Roll Cages to Chassis

8.2.1. Inthefollowingdrawings,therectangleidentifiedas“Chassis”canalsobetakentobeanoutrigger.Theattachmentprinciplesarethesame.

8.2.3. Thedrawing(8.2.2.)showsthebasicprincipleofa“U”-shapedchannelweldedoverthechassis.Theremustbenogapsbetweenthechannelandthechassis.

8.2.4. The“saddle”shownmaybeaninverted“U”channel,twolengthsofangleorthreeflatplates.Theobjectiveistospreadtheloadoveralargeareaofchassisratherthanconcentratetheloadsona2”/50mm(orthereabouts)diameterspot.

8.2.5. Roll-cagescanbemadedetachableasshowninthefollowingdrawings.The”U”-shapedsaddleisreplacedwithlengthsofangleandabase-plateisfittedtotheroll-cagetube.Theassemblyisthenboltedasshown.

8.2.7. Aboveleft:Boltingthroughafloor.Theangleironisweldedtothechassisandaspacer/packingpiecewillalmostcertainlybeneededtofillthegap.

8.2.8. Aboveright:Cut-awayornofloorpanel.Asbeforebuttheplatesitsdirectlyonthechassisandthespacerisnotrequired.

8.2.9. Inmanyoftheforegoingdrawings,apacking-piece/spacerisshownfittedbetweentheflooroftheloadareaandthechassis.Closefittingpiecesofmetalor‘Tufnol’orsimilarmaterial(butnotwood)thesamesizeandshapeasthefoot/base-platemustbeusedtopackthegapbetweenthechassisandthefloor.Itmaybenecessarytotaperthispackingduetothevaryinggap.Thealuminiumfloorwillnottakethestrainimposedbythelegs/feetoftheroll-cage.

8.2.10. Thebase-plate/feetshallbeatleast5”x5”x¼”/125mmx125mmx6mmsteelplate.Boltholesshallhaveatleast1½xbolt-diameteredgemargin,i.e.edgeofbolt-holetoedgeofplate,angleorbracketshallbeatleast1½timesthediameterofthebolt.(See8.2.11.)

7.8. Front Hoop Mounting to Outrigger on SI - III & 90 / 110 etc.

7.8.2. Thehoopisweldedtothesaddle,andthesaddleisattachedtotheoutriggerwiththehightensileoutrigger/bulkheadbolt(whichalsosecuresthebulkhead).

8. Main Hoops

8.1. Standard Design

8.1.1. Alldiagonalswillgotothetopofthedriver’sside.

8.1.3. Aboveleftshowsthebasicdesign.Thelesstheamountofbendatpoints‘a’and‘b’willproportionatelyincreasethestrengthofthebar.Thebendat‘a’caneffectivelybereducedto a straight tube as shown above right.


8.3. Standard Shape Hoop Mounting onto “A”-Frame Cross-Member.

8.4. Main Hoop Design and Installation for Range Rover / Discovery and other Long Wheelbase Station Wagons.

8.4.1. Thefollowingdesignhasbeendevisedtogiveaccesstotherearseatsinalllongwheelbasevehicles.Itisa“D”hoopmountedonasubstantialbox-beam.Themethodsofattachingthehooptothebeamandthebeamtothechassisareshownindetail.Thediagonalcangoineitherthe“a”orthe“b”position.Thediagonalandtherearbracescanbemadedetachableusingmethodsshownlater.OnaRangeRover,therearbracesjustclearthetopofthebackseats.

8.4.3. ThedesignshownaboveisforuseinRangeRover,DiscoveryandanyotherLongWheelbasestation-wagonvehicles.Theygiveamorestablebaseduetotheextrawidthofthese vehicles and give back seat accessibility

8.2.12. Theuseofflitchplatesorwebsaroundthebaseofthebarsandbracingwillgreatlyincreasethestrength.Allbase-platesshallbeatleast125mmx125mmx6mm/5”x5”x¼”thickmildsteel.

8.2.13. Holeedgemargin“m”shownonsketch8.2.11shallbeatleast1½xholediameter.Thisappliestootherbracketsandplates.

8.2.15. Aboveisatypeofmountingenablingtheroll-cagetoberemovedleavingonlythesocketinsituinthevehicle.Thisissuitableforeitherthefrontorbackhoopasabasefootmounting.

8.2.17. Rightisatypeofmountingthatfillsthegapbetweenthechassisandthefloor,enablingtheroll-cagetoberemovedeasily.Theheightofthetopplateabovethechassiscanbevariedto suit the vehicle.


8.6.4.OnDiscoveriesandlaterRangeRovers,thefloorpanelsareweldedin.Themethodshownatleftcanbeusedtomountthebox-beambelowfloorlevelbycuttingthebeamby2”tofitoverthechassis.Anglesweldedatthejointsshouldadequatelyrestoretheareatofullstrength.

8.6.5. Thismethodisstrongerthanreinforcingexistingoutriggersoraddingfabricatedones.8.6.6. Spreaderplatesarenotrequiredwheretheroll-cagetubeisweldedonto¼”/6mmwall

thicknessboxmaterial.

8.7. Roll-cages on 101” Wheelbase Forward Control Land Rovers

8.7.1. Themajorproblemwiththisvehicleisthattheroll-cageneedstostraddletheenginemakingitimpossibletoruntherequisitediagonalfromthetopcornerofthehoopdowntothechassisinthenormalway.Thisparticularvehicletypewasnotconsideredwhentheoriginalroll-cageregulationsweredrawnup.ThefollowingdesignhasbeenpassedbytheALRCCouncilandtheScrutineeringCommitteeforuseonthisvehicletypeonly.

8.7.2. Theoutriggerscaneasilybere-inforcedifnecessarywiththeadditionofa6mm/¼”topplateextendingontothetopofthechassis.Thecabcansitontopofthistoo.Thereareusuallysomeshimsbetweenthecabfeetandthetopoftheoutrigger(typically3mm/1/8”)buttheadditionofthereinforcingplatewouldraisetherearofthecabbyamaximumof6mm/¼”.Thisshouldn’tcauseaproblemasthecabisalargeunit.

8.7.3. Additionalsideplatescanbeaddedtothefrontfaceoftheoutrigger.Thereareusuallysomeshims(typically3to6mm/1/8”to1/4”)betweentherearfaceoftheoutriggerandthefrontfaceofthebackbodyunit.Buildingthisupto6mm/¼”shouldn’tbeaproblemas,atworst,thebackbodywillbepushedbackbythisamount.(maximum)

8.7.4. Ifthefueltankistobeleftinitsoriginalposition,thenthepetrolfillerpipewillneedtobere-routed.Therubberfillerhosegoesfromthefillerpoint,intothevoidbehindthefrontseat

8.5. Methods of attaching the hoop to the box-beam

8.6. Methods of attaching the box-beam to the chassis.

8.6.2. OnearlyRangeRovers,therearfloorcaneasilyberemovedandnewpanellingfittedroundthisassemblyafterinstallation.


8.7.11. Thedrawing8.7.12.showsaplanviewoftheoutrigger.

8.8. Diagonal Braces for Main Hoops

8.8.2. Thediagonalshalltouchthebase-plate,ifonlybyitstip.Seedrawing.

andthendownthroughthetopsurfaceoftheoutriggerandthenoutoftheaftfaceoftheoutriggerandintothetank.Anewpipetothetankcouldeasilybemadefromacombinationofmetalpipeandrubberhose.Aroutesimilartotheoriginalcouldbeusedoralternatively,itcouldeasilybemadetopassdownwardsfromtheaforementionedvoidtoapointaheadofthe outrigger and then go rearwards right through the outrigger and into the tank.

8.7.5. Onthelefthandside,theairfilterwillneedtobemoved.8.7.6. Thehoopwillbeattachedtothetopofthere-inforcedoutrigger55mm/2¼”infromthe

endasthecabmountframeboltsthroughrightattheextremeoutboardend.Thehoopwillbeadequatelywideatthisposition.Ifneeded,thehoopwidthcouldstepouttofullvehiclewidth once clear of the cab structure.

8.7.7. Thetwodiagonalswouldgofromtheuppercornerbendstothetopofthechassisgivingabasewidthof500mm/20”.Theleft-handdiagonalcannowtuckinundertheoverhangingmanifoldandattachtothetopofthechassis.

8.7.8. Detailsonmaterials,fixings,welding,mounttypes,front-hoops,rearbraces,etc.canbefound earlier on in this set of regulations.

8.7.9. Thedrawing8.7.10.showstherelevantdesignanddimensionaldetailsofthehoop.


9.1.4. “A”showstherearbraceontopoftherearcross-member.Nochassissideplatescanbefitted,soaflatplateovertherearcross-memberandoverlappingontothechassisisacceptable.

9.1.5. “B”showstherearbracestillwellbackbutnotontopoftherearcross-member.Here,sideplatesorangleswillneedtobeusedperpreviousdrawings.

9.2. Rear Braces on Range Rover, Discovery, 90, 110 Defender etc.

9.2.1. Theawkwardshapeofthechassisonthecoilsprungvehiclescanleadtomountingproblems.Thefollowingsketchesmayhelp.Remember,outriggersandcrossmembersshouldbetreatedthesamewayasthemainchassisrails.

9.2.4.Thesketch9.2.3.abovemaynotalwaysworkoutexactlyasshownduetobracesbetweenthechassisandtherearcross-member,andthepointontheinnerfaceofthechassisrailwherethewiringloomemerges.Thesketchbelow(adaptedfromtheabovedrawing)showsthepatternofsideplatesthatcouldbeaddedtoa90thathasbeenfittedwitharoll-cageinthewaythatsomecommercialmanufacturersdo.Thebox-sectionupstandsaretobesecurelyweldedtothechassisfirstandthe¼”/6mmreinforcingside-platesaddedafterwards.

9. Rear bracing bars

9.1. General

9.1.1. Thefurtherbacktheyarethebetterandthesemayjointhechassisontopoftherearcross-member.Here,itwillnotbeeasytofittherequiredmaterialdownthesidesofthechassisasshownpreviously.Inthiscaseonly,thesideplatesmaybedispensedwithsolongastheweldinggoesallroundtheplateonthetopandunderneathasshownbelow.Agussetplateisadvisableand,preferably,leavethebase-platerectangularasshownandnottrimmedtoaTshape.Thereasonforthisdesignbeingacceptableisthatthisisaverystrongpartofthe chassis.


11. Joints various

11.2. Methodofattachingrearbrace.Notethattheplugisroundwhereitfitsintothetubeandsquarewheretheflatplatesarebolted.

11.4. Methodofattachingrearbraceinwhichtwomirror-imageplugsareweldedintothetubesand held with a high tensile nut and bolt.

10. Seat belt attachments

10.2. Seatbeltsmaybefixedtotherollcagebutthefixingmethodshouldnot cause any weaknesses.An‘eye’tappedintothebarorjustweldedonisinsufficient,use a load spreadingmethod.

10.4. Theseatbeltsthatpassovertheoccupants’shoulders can be lead over a structural tube where indicated in the drawing 10.5. andfixedatfloorlevel,orwrappedaround a structural tubeandrefittedusing the buckle. Thebeltitselfmustnotbealtered.Thiscannot be done with alltypesofbelt;onlythose that have an adjustingbucklethatcan be unthreaded.


12. Exemptions

12.1. Non-UK Registered & Resident Vehicles

12.1.1. Insomecountriesthe law forbids welding to the chassis of road-going vehicles.(Germany,France,Denmark,forexample).Competitorsfromsuch countries mayberequiredtoprovethataweldedassemblyisnotpermitted.Forvehicles registered andnormallyresidentin such countries, a bolted-on roll-cage mountisallowed.Therearbracemountislikethis:

12.1.4. Themainhoopmountisthesameasthe“old”bolted design and attachmentisbytheusual3/8”/10mmHTmountingbolts.

12.1.6. Allplatesaretobe6mm/¼”andnutsandboltstobe3/8”/10mmhightensileaselsewhere.

11.6. Sockettypeconnectionofrearbracetomainhoop.

11.8. Methodofmakingabracejoiner.Theboltsmustbenolessthan1¾”/42mmapartandnolessthan7/8”,20mmfromtheendofthetubes.

11.9. *Referencesonthe“joints”pagestoa½”/12mmhole*indicateswhereaholeofthatsizeisdrilledpriortoinsertionoftheplug.Theedgesoftheholearethentobeweldedtotheplugthatappearsthroughit. Please direct any enquiries to the ALRC Scrutineering & Off-Road Committee.

alrc roll-cage regulations 1 roll-cages · 2018. 3. 14. · the roll-cage field. 1.2.10. a...

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