Engistics Pty Ltd

AustralianForestryContractorsAssociation

TasmanianLoggingTiltTest

Author: JonathanVilaBEngReviewed: SeanCarlsonBEngCPEngRPEQDate: 11/12/2018Issue: Issue2FileNumber:E1073

ED559-Issue2 E01073-11/12/18 2

Engistics Pty Ltd

ExecutiveSummaryThetestingoflogfrictionandvariousloadrestraintsystemsinTasmaniashowedhighvaluesoffrictionforeachofthelogspeciestested,relativetootherfrictiontestperformedonvariouslogtypesinotherregions.AlogthatspearedduringtransitindicatesthatlowerfrictionnativePeelerlogsmayexist.Allbartworestrainedtestsmetthe0.8grequirements.Amanualwinchwebbingincombinationwithabellychainachievedthehighesttiltangleof55°(at1.14G),easilysurpassingthe0.8grequirements.However,itprovedtobeinconsistentinbothitsappliedtension.Dyneemaachievedthehighesttensionandwiththeuseofairwinchesachievedthemostconsistency.Thebellychaincommonlyusedintheindustryalsoworkedverywell.Thiswasespeciallytrueincombinationwithwebbingstraps.Finally,Gripplateswereseentobeveryeffectiveatholdingthebottomlayerofthelogs.

ED559-Issue2 E01073-11/12/18 3

Engistics Pty Ltd

AFCAloggingtilttest(TASonly)

Dateoftest:26-27/07/18,OranaEnterprisesPtyLtd,LeganaPark,Tasmania

EngisticsEngineersPresent:SeanCarlsonJonathanVila

Acknowledgements:Engisticswishestothankthefollowingorganisationwiththistesting:OranaEnterprisesPtyLtdForicoPtyLtdSustainableTimberTasmania(STT)ANCForestryForestCentre(Aust)PtyLtdAustralianForestryContractorsAssociation

TestGoals:Thepurposeofthetestingwasto:

1. DeterminethestaticfrictionoffourtypesofTasmaniantimber:E.NitensPulpwood,Nativepulp,NativePeelerandE.NitensPeeler.Theseweredividedintotwoseparatetestlengths:thefirstat6mandthesecondat12m.

2. Assessthedifferenceinfrictionbetween6mand12mloglengths.

3. Assessthechangeinlogbehaviourbetweenrestrainedandunrestrained.

4. EvaluateDyneemaasarestraintsystem.

5. FurtherevaluateBellyChainsintesting.

6. FurtherevaluateWebbingstrapsasarestraintsystem.

ED559-Issue2 E01073-11/12/18 4

Engistics Pty Ltd

TestMethodology:Thetestmethodattemptedtosimulatetheloadingoflogsontoaloggingtrailerbyhavingtwobolstersrestrainedtoa40ftflatrack.Thetestbedwasthentiltedfromoneenduntilthelogsmovedoruntilasatisfactoryanglereplicating0.8gwasreachedtosatisfyEN12195.Overtwentyseparatetestswereconductedaslistedinthetablebelow.Duringthesetests,thetypeoftimber,itslengthandtheangleoftheflatrackwererecorded.Alltestliftswererecordedviavideotocapturethemomentofmovement.

Figure1:6mPeelersonflatrack

Aheadboardwasfixedtotheforwardbolsterframetobothreducetheamountoflogmovementandreducecleanuptimeiflogsweretomoveoutofthebolsters.

ED559-Issue2 E01073-11/12/18 5

Engistics Pty Ltd

Figure2:6mlogstestsetup

Thetesthowever,didhavecertainlimitationssuchas:

• Reducedanglerangeduetothescaleofthetestandcraneconstraints• Craneconcernsoverstabilityoftestrig• Headboardsafety,thebaymasswasreducedtoensuretheheadboard

couldadequatelyblocktheload• Deformationoftheflatrackanchorpointsduetheliftingchainapplying

highlyconcentratedloads• Concernsofoverturning

AllconcernsweredocumentedintheRiskAssessmentpriorandduringthetesting.

ED559-Issue2 E01073-11/12/18 6

Engistics Pty Ltd

Equipment:Thetestsinvolvedavarietyofequipmentbothtomeasureandrestrainthelogs.Suchequipmentincluded:

• ElphinstoneEngineeringfabricatedLogbolsterswithroundpegsandgripbarstoreplicatethetransportoflogsontrailers

• 75mmWebbingstraps;• Elphinstonemanualloadbinders• BellyChaintensionedbyamaxibindermanualtensioner• 5m10tonWLLDyneemaropeswereusedfortherestrainedtests• 1x3ttensionLoadcell,1x5ttensionLoadcellformeasuringtensionin

thetiedownsystem.• Airwincheswithanapproximateairsupplypressureof100psi.• 2xExTeTU16winchesconfigured1:1forWebbingorDyneemaas

required• Variouscamerasandtestequipmenttomeasureangleandmovementof

logs• 40ftflatrack• 85tonboomcrane

Figure3:AirWinchsetup(withTensionLoadcell)vsManualwinchsetup

Figure4:AirWinchwithDyneemapostlogmovement

Tension Load cell

Dyneema/webbing strap

8mm Chain on air

Staunchion

ED559-Issue2 E01073-11/12/18 7

Engistics Pty Ltd

Results:

Test Size(m) Type Angle Friction Effective

G-ForceRestraintmethod Comments

1 6 E.NitensPulp(Forico) 42 0.90 0.9 1 Toptierlogsmovement

2 6 E.NitensPulp(Forico) 43 0.93 0.93 1 Fulllogmovement

3 6 E.NitensPeeler(Forico)

- NA NA 1 FulllogmovementWet,Equipmentfailure

4 6 E.NitensPeeler(Forico)

40 0.84 0.84 1 Wet,angleadjusted,toptiermovement

5 6 E.NitensPeeler(Forico)

47 0.84* 0.74^ 4 Toptiermovement,wetandangleadjusted

6 6 E.NitensPeeler(Forico) 40 0.84* 0.71^ 2 Toptiermovement

7 6 E.NitensPeeler(Forico) 55 0.84* 1.14^ 3 Nomovement

8 6E.NitensPeeler

(Forico) 53 1.33 0.84 8 Nomovement

9 6 NativePeeler(STT) 40 0.84 0.84 1 Fullmovement,BlockingWebbingstrapfailure

10 6 NativePeeler(STT) 37 0.75 0.75 1 Fullmovement

11 6 NativePeeler(STT) 47 0.8* 0.85^ 4 Dyneematest

12 6 NativePeeler(STT) 49 0.8* 0.94^ 5 Dyneemawithbellystrap(chain)

13 12 NativePulp(STT) 42 0.90 0.9 1 Nomovement

14 12 NativePulp(STT) 41 0.87 0.87 1 Nomovement

15 12 NativePulp(STT) 50 0.88* 1.04^ 4 Nomovement

16 12 NativePulp(STT) 50 0.88* 1.04^ 6 Nomovement

17 12 E.NitensPulp(Forico) 37 0.75 0.75 1 Fullmovement

18 12 E.NitensPulp(Forico) 37 0.75 0.75 1 Fullmovement

19 12 E.NitensPulp(Forico) 52 0.75* 1.09^ 7 NoMovement

20 12 E.NitensPulp(Forico) 50 0.75* 1.00^ 5 Toptiermovement

21 12 E.NitensPulp(Forico) 49 0.75* 1.03^ 4 Fullmovement

22 12 E.NitensPulp(Forico) 46 0.75* 0.96^ 2 Fullmovement

Table1:Initialresults

*Assumedfromunrestrainedtest^Calculated

ED559-Issue2 E01073-11/12/18 8

Engistics Pty Ltd

Restraintmethod

1 Unrestrained

2 2x75mmWebbingonExTeWinch

3 2x75mmWebbingstrapsonExteWinch,BellyChain

4 2xDyneemaonExTeTU16

5 2xDyneemaonExTeTU16,BellyChain

62x75mmWebbingstraps,

ElphinstoneManualwinch,bellychain

7 2xWebbingstraps,Elphinstonemanualwinch

8 BellyChainonly

Table2:RestraintMethod

Day1oftestinginvolvedonly6mlogsandday2,only12mlogs.Thisallowedminimumdelaysforsettingupthetestrig.Ingeneral,alltypesoftimberweretestedbothunrestrainedandrestrained.Inthecaseoftherestrainedtests,amixofwebbingstrapsandDyneemawereusedforrestraintsaswellaschainbellystrapstounitisethelogs.Itmustbenotedthatinsomecases,tiltingofthetestrigwaslimitedduetosafetyconcernsrelatingtocranestability.Thislimitedboththetiltangleaswellasthetotallogsputonthetestrigitself.Test3wasdisregardedduetoamalfunctionoftheanglemeasurementequipmentduringtesting.Itwasfixedforthefollowingtests.E.NitensPulpwastestedinprevioustestingat6mandwasthusonlybrieflytestedatthislength.Itfeaturedmoreheavilyontheseconddaywith12mlogtesting.E.NitensPeelerandNativePeelerswereonlytestedduringthefirstdayat6mlengths.NativePulpwasonlytestedontheseconddayat12mlengths.Theresultsshowextremelyhighanglesoftiltbeforemovementandinsomecases,nomovementatall.

ED559-Issue2 E01073-11/12/18 9

Engistics Pty Ltd

Analysisofresults:

FrictionofTasmanianlogs:Thefrictionofthelogswasevaluatedusingrestrainedandunrestrainedtests.AnunrestrainedtestevaluatesthefrictionusingasimpleprocessoftakingtheTangentoftheangletodeterminefriction.Therestrainedtestincludestheeffectoftiedownforceintheformulafordeterminingfriction.Inbothcases,ahigherangleoftiltequatestoahighercoefficientoffriction.Thestaticfrictionforunrestrainedtilttestsiscalculatedusingtheformula:

µ=Tan𝜃

Thestaticfrictionforrestrainttilttestsiscalculatedusingtheformula:

𝑚𝑔× sin𝜃 = 𝜇 ×((𝑚𝑔× cos𝜃)+ 𝐹! )

𝑤ℎ𝑒𝑟𝑒: 𝐹! = 𝐶𝑙𝑎𝑚𝑝𝑖𝑛𝑔 𝑓𝑟𝑜𝑚 𝑙𝑎𝑠ℎ𝑖𝑛𝑔: 𝑇 × 𝑠𝑖𝑛𝐸 × 𝑔

𝜇 = 𝑓𝑟𝑖𝑐𝑡𝑖𝑜𝑛 𝑜𝑓 𝑙𝑜𝑔𝑠

𝑇 = 𝑡𝑒𝑛𝑖𝑠𝑜𝑛 𝑜𝑓 𝑙𝑎𝑠ℎ𝑖𝑛𝑔 𝑖𝑛 𝑘𝑔

𝑚 = 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑙𝑜𝑔𝑠 𝑖𝑛 𝑘𝑔Hence:

𝜇 =𝑚𝑔× sin𝜃

((𝑚𝑔× cos𝜃)+ 𝐹! )

Belowisanexampleofanunrestrainedtest:Test1,UnrestrainedE.NitensPulpwoodwithamovementofthreelogs:

𝜃 = 42 𝑑𝑒𝑔𝑟𝑒𝑒𝑠

𝜇 = tan 42

𝜇 = 0.9

ED559-Issue2 E01073-11/12/18 10

Engistics Pty Ltd

Test Size(m) Type Angle Static

Friction

AverageStaticfriction

1 6 E.NitensPulp 42 0.900.92

2 6 E.NitensPulp 43 0.93

4 6 E.NitensPeeler 40 0.84 0.84

9 6 NativePeelers 40 0.840.80

10 6 NativePeelers 37 0.75

13 12 NativePulp 42 0.900.88

14 12 NativePulp 41 0.87

17 12 E.NitensPulp 37 0.750.75

18 12 E.NitensPulp 37 0.75Table3:Frictionvaluesoflogs(Unrestrained)

ThetilttestinginTasmaniashowedveryhighcoefficientsoffrictionacrosstheboard.Howeverprevioustestingofsimilartypelogs,specificallyintheGreenTriangleRegionidentifiedlowerfrictionvaluesforPulplogs(Globulus).OurcomparisonslookatNativePeelersversusMountainAshandE.NitensPeelerversusRB40(Pinesawlogs).Engisticsrecognisesthattherearedifferencesbetweenthesespeciesandishappytohaveclarificationtoimprovethecomparison.RestrainttestingusingeitherwebbingorDyneemashowedtheymettheperformancestandardsatthisfrictionattimeoftest.

Figure5:Logmovementintransit

ED559-Issue2 E01073-11/12/18 11

Engistics Pty Ltd

Anissuethatarose(relatingtothecurrentfrictionofthelogs)wasthatduringtransittothetestsite,oneoftheNativePeelerlogsspearedforwards.Inthiscase,thelogswererestrainedusingwebbingstrapstensionedwithabasiccommonhandoperatedwinch.Thedriveradvisedthatnoheavybrakingorimpacthadbeenexperiencedintransit.Thiswouldindicatethatdecelerationoccurredthroughmoderatebrakingwhichwouldtypicallyprovideforcesonthelogsofbetween0.55to0.6g.Inthiscase,eveniftheappliedloadrestrainthadaminimalimpactonthelog,andthemovementcamefromfrictionalone(bestcasescenarioforthehighestfriction),thestaticfrictionwouldbeintherangeof0.55-0.6.OurobservationisthatthelogthatmovedintransitiscomparableinfrictiontoMountainAsh.Engisticscanonlytheoriseonthisincreaseinfrictionbetweenintransitloadshiftandinrigresults;however,itcanpossiblybeattributedtoafewlikelycauses:

• Traveltimesbetweenloggingoperationsandtestsitecouldhaveallowedconvectiondryingtoimpactfriction;

• Differencesintestrackconfigurationcomparedtoonvehicleloadconfiguration.

• Seasonaleffects• Increasedlogmarksfromwinteroperations.• Timebetweenharvestingandtransport

CommentaryProvidedbyForicoindicatedthatduringwinter,additionalmarkingonthelogsoccurduetooperationalrequirementswhenremovingbranches.Thiswouldhavethepotentialtocontributetheincreasedfrictionofthelogsduringtesting.ThetimingofthelogsfortestinginrelationtothetimebetweenharvestingandtransportingisreflectiveofmostlogtransporttasksinTasmaniafromdiscussionswithoperatorsduringtesting.Duetothehighfrictionoflogsfound,thenextstepwastoreviewtheeffectivenessofloadrestraintsystems.Thisincludedusingacombinationofwebbingstraps,airwinches,manualwinchesandbellychains.Dyneemawasalsoextensivelyusedtodetermineitseffectivenessasapotentialalternativerestraintsystem.Theeffectivenessofarestraintsystemismeasuredbyitsappliedtensionandtensionloss.Thehighfrictionofthelogsassistedgreatlytotheperformanceoftherestraintsystem.

ED559-Issue2 E01073-11/12/18 12

Engistics Pty Ltd

SummaryofDyneematensions:Dyneemawasheavilyfeaturedintherestrainedteststoreviewitseffectiveness.Theresultsbelowshowthemeasuredtensionsonboththehighandlowsideswiththehighsidebeingthesideoftheairwinch.

Figure6:6mPeelers

Test Size(m)

Type Tension(High)kg

Tension(Low)kg

DifferenceHightoLow

(%)5 6 E.Nitens

Peeler510 402 79

11 6 NativePeeler

560 360 64

15 12 NativePulp 722 380 53

Airpressureapproximate100psibasedon50mmgaugefromtruckcompressor.

Table4:DyneematensiondifferencebetweenLowandHigh

ThetensionintheDyneemawasnotconsistentbetweentestsbutregisteredhigherthanwebbingstraps.Tensioninthe12mlogsregisteredthegreatestdisparitybetweenHigh(left)endandlow(right)side.Previoustestingfoundthattheratiobetweenthelowsideandhighsidewasaround43%.Currenttestresultsarehigherthanthisvalue,suggestingthatthetestsetupwascorrect.However,ourDyneematensionvaluesdonotalignwithvaluesfoundduringprevioustesting(1000kg-1200kghighsidecomparedtocurrenttestresultsof500-700kghighside).Thissuggeststhatthetestairpressurewaslikelylessthanpreviouslyunderstoodwheremajorityofprevioustestswerearound115psi.Thisispotentiallyattributedtothegaugeresolutionnotpermittingaccuratepressuremeasurement.AnEngisticslearningfromthisprocessistoensurehigherresolutiongaugesareavailablewhenperformingsimilartests.

ED559-Issue2 E01073-11/12/18 13

Engistics Pty Ltd

BellyChain:TestingwascompletedwithvariousrestraintsystemsincludingcombinationsofDyneema,75mmWebbingstrapsandBellyChainscombined.Bellychainwastensionedwithamaxibindermanuallytensioned.Thetablebelowprovidesacomparisonoftestsforsystemswithandwithoutbellychainsapplied.

Test Size(m)

Type Angle(degrees)

G-Force Restraint Comments

6 6 E.NitensPeeler

40 0.71 2xWebbingstraps Toptiermovement

7 6 E.NitensPeeler

55 1.14 2xWebbingstraps,BellyChain

Nomovement

8 6 E.NitensPeeler

53 0.84 BellyChainonly NoMovement

11 6 NativePeeler

47 0.85 2xDyneema Dyneematest

12 6 NativePeeler

49 0.94 2xDyneema,BellyChain Dyneemawithbellystrap(chain)

19 12 E.NitensPulp

52 1.09 2xWebbingstraps,manualwinch,BellyChain

NoMovement

20 12 E.NitensPulp

50 1.00 2xDyneema,BellyChain Toptiermovement

21 12 E.NitensPulp

49 1.03 2xDyneema Fullmovement

Table5:BellyChaineffect

Theresultsoftest19areonlyincludedforcompleteness,asatestwasnotundertakenwithoutabellychainforcomparison.InthecasewhereDyneemawasused,asmallincreaseinrestraintcapacity(by1-2degrees)wasseenwhenaBellyChainwasapplied.However,therewasadramaticincreaseinrestraintcapacitywhenabellychainwasusedincombinationwithwebbingstraps(atotalof15degreesincreaseintest7comparetotest6).ThisisalsohighlightedbytheG-forceachieved:Intest6the0.71Greachedwouldhavemeantthattheloadwouldnothavesuccessfullyachievedtherequired0.8G.However,theadditionofaBellyChaingreatlyincreasedtheG-forceto1.14G.

ED559-Issue2 E01073-11/12/18 14

Engistics Pty Ltd

Figure7:6mSawlogtestingwithbellychain

ThisdiscrepancybetweenDyneemaandwebbingstrapsismostlikelyattributedtothedifferenceintensionbetweenthetwo.Inallcases,Dyneemaregisteredhighertensionvaluesthanwebbingstraps.ThiswouldmeanthatabellychainplayedagreaterroleintherestraintofthelogswithwebbingthanitdidwhenusedinconjunctionwithDyneema.Interestingly,test8showedthatabellychainonitsownachievedtherequired0.8G.Thisindicatesalogfrictionof1.33.Thisresultshowsthevalueofabellychainandisindicativeofthegainsachievedwithitsusage.Thefrictionvaluesobtainedintestingalsoassisttheperformanceoftheloadrestraintintesting.Thisisacommonfeatureofalltests.

ED559-Issue2 E01073-11/12/18 15

Engistics Pty Ltd

WebbingtensionLoss:Whilstwebbingstrapswereusedforseveraltests,wenoticedamarkeddecreaseintensionovertimeaswellaslowertensionvaluesoverall.Test Size

(m)Type HighTension

(kg)LowTension

(kg)DifferenceHightoLow(%)

6 6 E.NitensPeeler

340@approx1min

127@approx1min

37

7 6 E.NitensPeeler

400@approx1min

125@approx1min

31

16 12 NativePulp Elphinstonemanualwinch

522

400 76

19* 12 E.NitensPulp

Elphinstonemanualwinch

InitialTension:@approx1min

640 320 50

Tension@midtest: 540 320 59

Tension@endoftest(0degreestilt)

330 350 106

*Dataappearsinconsistent

Table6:WebbingtensiondifferenceLowtoHigh

From the table above, the tests that usedwebbing straps showed a significantdecreaseintensionvaluescomparedtoDyneemafortheExTeTU16winch.During test 19, the tension loss over time was recorded for an Elphinstonemanualwinch.ThetensiondropovertimewiththeElphinstonewinchwaslessthan with the ExTe TU16. This is thought to be related to the higher initialtension provided by the Elphinstone winch transferring more effectively overtheload.Whilst the initial tension was higher than the ExTe winch, the tension valuedropped significantly through the test process. This highlights the concernsrelatingtomaintainingtensionovertimeformanualtensioningsystems.A significant variation in tensions achieved by the manual Elphinstone winchwasidentifiedduringtesting.Thisisevidentinthedifferencebetweenthehighsidetensionsfortests16and19thathavea120kgdifference.Whilst the Elphinstone manual winch provides an initial total clampingcomparabletotheDyneemasysteminthistest,itisevidentthatthatthistensionisnoteasilymaintainedovertime,includingintransit.

ED559-Issue2 E01073-11/12/18 16

Engistics Pty Ltd

At theendof the testingday, a tension loadcellwasmountedon thewebbingstrap of a logging trailer. The purpose was to see the change in tension indynamicconditions.Theinitialtensioningofthestrapsshowedavalueof640Kgonwinch side.Within 15minutes, that value had dropped to 580kg onwinchside.Fromthere,thetruckandtrailerwasdrivenfor20minutesfor15km.Atthefirststop,theloadshowedavalueof397kg, i.ea lossintensionofover200kg.The loadwas re tensionedand thedrivena further15km.On the secondandfinalstop,thetensionremainedconstantat550kg.The testing showed that usingwebbing straps for restraintwas least efficientduetolargegapsbetweenlowandhighsidetension,aswellassignificantlossintensionovertimeinbothtestingandintransit.However,itisimportanttonotethatlossintensionispotentiallyduetothetestsetupwherealoadcellwasintroducedintotherestraintsystembymeansofasecondary system and choking. It is feasible that slippage occurred during thetestingorlogcompression,providedtensionlossesintheresults.ThetablebelowalsocomparesthedifferenceintensionbetweenDyneemaandwebbing.Tests5and6showthatduringSawlogtesting,Dyneema(test5)registeredhighertensionsthanwebbing(test6).Whilstintest19,thewebbingtensiondecreasedwhentestingbeganwhilstDyneemaremainedconstantintest20.

Test Size(m) Type Tension

(left)kgTension(right)kg

Restraintsystem Comments

5 6E.NitensPeeler 510 402

2xDyneemarope/ExTe16

winch

Toptiermovement,wet

andangleadjusted

6 6 E.NitensPeeler

340 127

2x75mmwebbing

strapswithExTe16Winch

Toptiermovement

19 12 E.NitensPulp

Initial:640Start:540@50:410End:330

Initial:320Start:320@50:410End:350

2x75mmWebbingstraps,

Elphinstonemanualwinch

NoMovement

20 12 E.NitensPulp

650 650

2xDyneemarope,ExTe16winch,Belly

Chain

Toptiermovement

Table7:DyneemavsWebbingtension

ED559-Issue2 E01073-11/12/18 17

Engistics Pty Ltd

12mvs6mlengths:The table below shows a comparison between E.Nitens Pulp 6m and E.NitensPulp12m,andE.NitensPeeler6mandNativePulp12mlogs.WhilstthereisanorganicdifferencebetweenNativepulpandE.NitensPeeler,thecomparisonwasmade due to the quantity of logs used and their similarity in diameter. Thiscomparison only compares unrestrained results. Due to time and availabilityrestrictions,notestingwasconductedon12mPeelers.InthecaseofNitensPulp,therewasasignificantdifferencebetweenthe6and12m lengths,with higher friction found the 6m logs. Thiswas reversed in thesecond comparison, with the 12m Native logs having a higher friction value(althoughnotasignificantincrease).Duetotheseresults,itisrecommendedthatthelowestfrictionvalueregardlessofloglengthbeconsideredduetoinconsistenciesoffrictionacrosslengths.Size(m) Type AverageFriction FrictionDataPoints

6 E.NitensPulp 0.92 0.900.93

12 E.NitensPulp 0.750.750.75

6 E.NitensPeeler 0.84 0.84

12 NativePulp 0.88 0.900.87

Table8:Loglengthcomparison

Lashinganglesoncentrallogs:Theanglesonthelashingsappliedtothecentrallogsinthepilewereverylowtonil.Thismeantverylittletiedownforcewasappliedtotheselogsandwasthemainreasonwhymanyofthetestssawspearingofthetoplayer.Thisitselfhighlightsoneofthemainissueswiththecurrentrestraintsystem:itseffectivenessisstronglydependentontheshapeofthelogpileinthebolsters.Acrowningeffectwouldallowincreaseddownwardsforcetobeappliedtothecentrallogsandprovideanoverallbetterrestraintsystem.However,achievingthiscrowningisdifficultandofteninconsistent.

ED559-Issue2 E01073-11/12/18 18

Engistics Pty Ltd

Figure8:Angleoncentrallogs

Potentialsolutionsinclude:

• Blockingorcontainmentmethodsofrestraint.• Anothersolutioncouldbetheestablishmentofacleardiagrammatic

standardonwhatgoodcrowninglookslikeforeachlogtype.• Finallybyhavingcamerasincludedincertainareasofforwardersor

loaderswouldallowoperatorstobettervisualisetheloadonthetruck.

Gripplateeffect:Agripplatewasusedinalltests.Theresultsshowthatthegripplateensuredthatthecriticalfrictionwasbetweenlogonlog,insteadoflogonsteel,whichhasalowerfriction.Theimagebelowofthedeformedplateshowsthattheplatedugintothelogsensuringimprovedfriction.Duetotheireffectivenessintesting,itisrecommendedthatgripplatesbeusedonhorizontalbedstoimproveloadrestraint.

Figure9:GriporCrocodileplate

ED559-Issue2 E01073-11/12/18 19

Engistics Pty Ltd

ConclusionOverall,thetestingshowedaveryhighstaticcoefficientoffrictionacrossalllogtypes.ApplyingarestraintsystemincreasedthecapacityofthelogstowithstandhigherG-forces.Thishadtheeffectofmakingitdifficulttounderstandthedifferencesbetweenlengthvariationsandrestraintsystems.Sincethetestingshowedsuchhighfrictionvalues,allrestraintmethodsweredeemedadequate:Webbingachievedthe0.8GrequirementsinallcasesexceptwhentestingE.NitensPeelers.ThisalsooccurredwhenDyneemaforthisparticulartest.Theadditionofabellychainimprovedallsystemstoachievethe0.8Grequirements.Duetothehighmeasuredfrictionofthelogs,eachloadrestraintmethodwasreviewedforitsefficiencyinbothitsappliedtensionandtensionlossovertime.Itisimportanttonotethatalackofcrowningofthelogsoftencausedthetoptierlogstomove.Logswereloadedandcrownedconsistentwithhowtypicalloadswouldbecompletedatalanding.

GoalOutcomes:Inlinewiththetestgoals,thefollowingoutcomeswereachieved:

1. ThestaticfrictionoffourtypesofTasmaniantimber:o Staticfrictionofallfourlogtypeswasfoundtobeveryhighas

seenbelow.Thisisinconflictwithprevioustestingwhichshowedlowervaluesforsimilarlogtypes.Thecauseofthiswasattributedtopotentialseasonalconditionsandconvectiondryingduringtransport.

Test Size(m) Type Angle Friction

1 6 E.NitensPulp 42 0.90

17 12 E.NitensPulp 37 0.75

4 6 E.NitensPeelers 40 0.84

9 6 NativePeeler 40 0.84

14 12 NativePulp 41 0.87Table9:Logtypefrictionvalues

ED559-Issue2 E01073-11/12/18 20

Engistics Pty Ltd

2. Thedifferenceinfrictionbetween6mvs12mbeamlengths:o Thedifferencesbetween6mor12mloglengthsinthetablebelow

showedthatusingthelowestfrictionvalue,regardlessofloglength,wasthemosteffectiveoptionduetotheinconsistenciesinfrictionwithdifferentlengths.Bytakingthelowestvalue,asystemofrestraintcanbedevelopedusingthelowestcommondenominatorandaccountforalllogtypes.

Size(m) Type AverageFriction

FrictionDataPoints

6 E.NitensPulp 0.92 0.900.93

12 E.NitensPulp 0.750.75

0.75

6 E.NitensPeeler 0.84 0.84

12 NativePulp 0.88 0.900.87

Table10:Estimatedfrictionvaluesbetween6mand12mloglengths

3. Changeinlogfrictionbehaviourbetweenlashedandunlashed:

o Lowcrowninganglesmeantthatspearingofthetopmiddlelogsaccountedformostlogmovements.Belowhighlightsthemainareasforlogmovementduringtesting.

o Thetestingshowednodiscerniblechangestofrictionvalueswhenlogswerelashedcomparedtowhentheywereunlashed.

4. EvaluateDyneemaasarestraintsystem:

o AcombinationofairwinchesandDyneemaprovedtobethemosteffectiverestraintsystematmaintainingconsistenthightensionsthroughouttesting.

o Dyneemaappearstobeasuitablelashingsystemfortherestraintoflogs.However,thisissubjecttoevaluationoflong-termwearandensuring110psiisachievedonairdelivery.

ED559-Issue2 E01073-11/12/18 21

Engistics Pty Ltd

5. FurtherevaluateBellyChainsintesting:o Theuseofabellychain,whilsteffectiveinbothrestraintsystems,

provedtoonlybeamajorinfluencewhenincombinationwithwebbingstraps.ThiscanbeattributedtomoreconsistenttensionvaluesfromtheDyneemaasopposedtothewebbingstraps andthelowerperformanceofthewebbingsystems.However,Bellychaintensionedwithanon-recoilingbinder(I.enoovercenterloadbinders)isrecommendedfortherestraintofNativeandNitenslogs.

Test Size

(m)Type Angle

(degrees)Restraint Comments

6 6 E.NitensPeeler

40 2xWebbingstraps Toptiermovement

7 6 E.NitensPeeler

55 2xWebbingstraps,BellyChain

Nomovement

11 6 NativePeeler

47 2xDyneema Dyneematest

12 6 NativePeeler

49 2xDyneema,BellyChain

Dyneemawithbellystrap(chain)

19 12 E.NitensPulp

52 2xWebbingstraps,manualwinch

NoMovement

20 12 E.NitensPulp

50 2xDyneema,BellyChain

Toptiermovement

21 12 E.NitensPulp

49 2xDyneema Fullmovement

Table11:BellyChaineffect

6. FurtherevaluateWebbingstrapsasarestraintsystem:

o TheuseofwebbingstrapswithanairandmanualwinchshowedlowertensionsinthelashingsthanwhenusingDyneema.

o Webbingstrapssufferedthemostlossintensionovertimeinbothtestingandintransit.

Othertestoutcomes:

o Airwinchesweremoreeffectivethanmanualwinchesastheywereabletomaintaintensionthroughouteachtest

o WinchtensionfromtheExteTUwasnotedtobealmosthalfthatofprevioustesting,whichwouldhaveasignificanteffectontheresults.Thisisthoughttobeduetolowairpressuredeliverytothewinch.Ahigh-resolutiongaugeshouldbeusedtoensure110psipressureisachieved.

o Gripplatesensuredfrictionoutcomeswerebetweenlogonlogandnotlogonsteel.Gripplatesprovedtobeeffective.