tree felling bookdocshare01.docshare.tips/files/7971/79710326.pdf · includes tree driving, back...

A Guide to Safety in

TreeFelling

and

CrossCutting

Published by the Occupational Safetyand Health Service,Department of Labour,Wellington,New Zealand.

First published: 1980Reprinted: 1982Revised: 1986Revised: 1989Revised: 1994Revised: February 2001

ISBN 0-477-03547-7

Contents

ABOUT THIS BOOKLET..............5

SECTION ONE: TREE FELLINGAND CROSSCUTTING ...........7-40

Preparing for Work .................. 8

Know Your Limitations .......... 11

Preparation for Felling ........... 12

Preparing the Felling Site ....... 16

Basic Felling Techniques ....... 18

Felling Large Trees ................ 21

Additional Techniques ........... 24

Some Felling Hazards andDifficulties ............................ 28

Preparing for Crosscutting ..... 32

Tips for Safe Trimming .......... 33

Techniques for Crosscutting .. 35

SECTION TWO: ADVANCEDTECHNIQUES FOR EXPERIENCEDPEOPLE ............................41-59

Felling Heavy Leaners ............ 42

Trees with More than OneLeader on Trunk.................... 44

Winches and Wire Ropes ....... 46

Back Pulling .......................... 48

Tree Driving .......................... 53

Working in Windthrow ........... 57

5TREE FELLING

About ThisBooklet

MANY New Zealand farmers andhome handypeople fell trees — to

clear land, to provide fencing for farmand garden, to provide logs for timber,to open up sections, to let sun intobuildings or crops, or for firewood.

Once felled, the trees are cut for easeof handling, whether for logs andproduce, for disposal by dumping orchipping, or for burning as firewood.

The Occupational Safety and HealthService (OSH) is concerned at thenumber of people who sufferaccidents while tree felling andcrosscutting and has produced thisbooklet for the guidance of those whoare inexperienced in this work. It isnot intended for the professionalwhose work is covered by detailedsafety codes.

This booklet outlines the safepractices that have evolved in, and areendorsed by, the New Zealand loggingindustry.

In the first section, there are details ofpreparation for the felling operation,information on correct tree felling andcrosscutting methods, tips on how toovercome simple problems that mayoccur, and advice on tasks that youshould not tackle unless you aretrained and experienced.

6

The second section contains advice onwork that should be undertaken byexperienced people only. Thisincludes tree driving, back pulling,working in windthrow areas and fellingheavy leaners.

Before you do any tree felling orcrosscutting, you should beexperienced in the use of chainsaws.If you’re a novice, it’s sensible to gettraining from a qualified person or tohave an experienced person guide youthrough the procedures and make youaware of hazards.

Training may be available from yourchainsaw dealer or a qualifiedinstructor in your area. OSH forestoperations inspectors frequently runcourses on chainsaw use for the publicor special groups.

This booklet has been produced as acompanion to the OSH publication AGuide to Safety with Chainsaws, whichis available at all OSH offices. Keepthe two booklets together with yourchainsaw instruction manual for easyreference.

7

SECTION ONE:

TREEFELLING

ANDCROSS

CUTTING

8 TREE FELLING

PreparingFor Work

YOU should only undertake fellingand crosscutting of trees if:

☛ You are physically fit andreasonably active.

☛ You are trained or experienced inthe use and maintenance ofchainsaws.

☛ You have been trained in or areexperienced in felling andcrosscutting of trees; or

☛ You are being trained on a one-to-one basis by a competentperson.

☛ You have a person with you whois able to assist or obtain help inan emergency. Never work alonewhile felling trees or using achainsaw.

☛ You are not under the influenceof drugs or alcohol or are tired orfatigued.

☛ You are fully equipped to carryout the job.

WHAT YOU NEEDLet’s check the equipment you’llrequire. You need:

☛ Personal safety equipment, asdescribed in the OSH Guide toSafety with Chainsaws and shownin the illustration. Don’t forgetyour first aid kit.

9TREE FELLING

Personal safety equipment.

☛ Chainsaw, files and guides andtool kit. Your chainsawmanufacturer’s booklet.

☛ Fuel and oil containers that areproperly constructed for thepurpose. Don’t use glass or softplastics.

☛ Wedges and driving tools. Haveat least two wedges. High-densityplastic or soft metal are best.

☛ Canthooks. These are handy forrolling small trees, or rolling andholding logs to assist withcrosscutting.

Chainsaw operatorsafety trousers (orchaps)

Safety boots withsteel toecaps

Safety helmet(medium protectionor better)Grade 4

earmuffs

10 TREE FELLING

☛ A felling lever. This is useful forsmall trees, and one with a hookcan be used as a canthook.

Felling lever with hook.

☛ An axe. You may prefer to trimwith an axe. It’s also useful forsplitting large firewood blocks.

Lift

RollRoll

PullUse to roll trees or logs

11TREE FELLING

Know YourLimitations

THERE are some felling methodsand situations that should only be

tackled by experienced tree fellers orprofessionals. While some aredescribed later in the booklet, they arelisted here for your guidance.

These are jobs for experienced peopleonly:

☛ Working in windthrow or withwind-affected trees.

☛ Felling large, heavily branchedshelterbelt trees.

☛ Felling trees with a heavy lean.

☛ Felling trees that are liable tosplitting or slabbing. Willow andtawa are two examples of suchtrees.

☛ Felling trees on steep slopes orunstable ground.

☛ Working on or felling trees thatoverhang powerlines, buildings orpublic access ways.

☛ Driving trees one on to another.

☛ Back pulling trees.

☛ Felling dead trees.

12 TREE FELLING

Preparation ForFelling

THERE are two main things toconsider when preparing for

felling— the general work area and theindividual tree to be felled.

CHECK WORK AREAIt’s important to check the work areafor hazards before you start felling orcutting. Under the Health and Safety inEmployment Act 1992, you arerequired not to do anything that willharm another person in any placewhere you work (this includes harm toyourself).

☛ Check that there are no otherpersons, children or animals inthe work area. Make sure that nopeople with you, unless acting asan instructor or assistant, arewithin two tree lengths of the treeto be felled. This distance shouldbe increased if felling is downhill.

☛ Check for hazards in the areasuch as electricity or tele-communication lines. Seekadvice from the local controllingauthority if in doubt.

☛ If any road, railway or publicaccess way is within two treelengths of your work area, contactthe controlling authority to findout what precautions they require

13TREE FELLING

to prevent harm to other peopleand property.

☛ Check there are no buildings,equipment, fences or above-ground reticulation pipes withintwo tree lengths of the directionof fall of the tree.

With checking completed andprecautions taken as necessary, you’renow ready to look at the individualtree to be felled.

ASSESS TREE TO BE FELLED☛ Where possible, plan to fell the

tree so that it clears anyobstructions and falls into a clear,open space.

☛ Check for any dead or brokenbranches or any debris that maybe dislodged and fall into thework area as the tree falls. This isparticularly common in oldshelterbelt trees and causesmany serious accidents everyyear. View the tree from differentangles so you don’t missanything.

☛ Look for branches interlockingwith branches of other trees.These can break off as the treefalls and drop into the work area,pull the tree away from thedesired direction of fall, or causeother trees to uproot and fall.

☛ Note any vines which may affectthe direction of fall.

☛ Look for any rot around the baseof the tree where the felling cutsare to be made. These may affect

14 TREE FELLING

the direction of fall.

☛ By looking at the lean of the tree,the location of the heaviestbranches and the general crownweight, you’ll be able to selectthe direction of fall.

☛ Wind can affect the fall directionand must be considered alongwith the other points. Don’t felltrees in high winds or poorweather.

☛ If wedges or other felling aids willbe required, have them ready.

15TREE FELLING

☛ HAZARD WARNING

Check For Overhead HazardsMaterial falling into the work area isone of the most common causes ofaccidents when felling trees. Becauseof the height from which the materialfalls, severe or fatal injuries canresult. Old trees and shelterbelttrees are those most likely to havematerial lodged in the crown. Deadbranches, broken tops and cones arecommon.

Make sure you thoroughly check thetree to be felled and prepare yourescape route as described later.Watch for falling material even afterthe tree has hit the ground.

Check for hazards overhead before felling.

16 TREE FELLING

Have an escape route prepared.

D A N G E RA R E A

ESCAPEROUTE

D A N G E R A R E A

Direction of fall

ESCAPEROUTE

Preparing TheFelling Site

HAVING assessed the work areaand tree to be felled, you now

have to prepare the site for felling.

☛ If there are any low branches thatmay get in the way as you makethe felling cuts, cut them off.

☛ Be careful not to use the tip ofthe guide bar while clearingaround the tree. Work in ananticlockwise direction, keepingthe tree between yourself and thesaw guide bar where possible.

☛ Clear an adequate work areaaround the base of the tree andprovide an escape routediagonally to the rear, asillustrated below.

17TREE FELLING

☛ Look forward in the direction offall and identify any hazards suchas stumps, logs, or groundundulations that may cause thefallen tree to kick backwards orsideways on contact.

☛ If you have identified hazardssuch as material that may fall intothe work area, your companionshould take up a position wherethey can clearly see the hazardand can signal to you if there isdanger as you make the fellingcuts.

You are now ready to start the first ofthe felling cuts.

18 TREE FELLING

Basic FellingTechniques

THERE are three essential parts youneed to consider when felling any

tree over 200 mm in diameter.

They are the:

— scarf;

— backcut, and

— hingewood.

Let’s look at these in turn.

Scarf, backcut and hingewood.

THE SCARFThe scarf is important because it:

— controls the direction of fall;

Hingewood

Backcut(always abovescarf)

Direction of fall

Scarf

Direction of fall

Scarf (one-quarter toone-third thediameter ofstump)

Backcut

19TREE FELLING

— allows the tree to fall freely in thechosen direction;

— minimises splitting or slabbing.

The top cut is made first at a 45° anglebetween one-quarter and one-third ofthe tree’s diameter. The cut mustaccurately face the desired direction offall and finish level. The bottom cutmust be made level to meet the topcut and form a clean, uniform “V” rightacross the diameter of the tree whenthe cut section is removed.

HINGEWOODThis should be equal to one-tenth ofthe tree’s diameter and is left uncut asthe backcut is brought towards thescarf. This wood:

— acts as a hinge and controls thetree’s direction of fall;

— prevents the tree from twisting orbreaking sideways when falling;

— prevents the tree from fallingbackwards if the backcut closes.

THE BACKCUTThe backcut cleans out the wood fromthe back side of the tree to leave thehingewood and allow the tree to fall.

The backcut is made level and alwaysabove the ‘V’ of the scarf. As a guide,it should be at least one-tenth thediameter of the tree above the scarfbut never less than 50 mm and amaximum of 200 mm for large trees.

If you are in any doubt as to the leanof a tree, insert a holding wedge in thecut as soon as practicable and drive ithome as the cut proceeds.

20 TREE FELLING

The backcut is taken up until there isan even amount of hinge wood aboutone-tenth of the tree’s diameter andparallel to the scarf. The cut mustnever be taken up to or beyond thescarf cut as the hingewood iseliminated and there is no control overdirection of fall.

Once the backcut has been taken upand the tree begins to fall:

☛ Remove saw from the cut andswitch off.

☛ Move into the planned escaperoute.

☛ Watch for falling material.

☛ Watch for the tree kicking back orbouncing as it hits the ground.

21TREE FELLING

Felling LargeTrees

WHERE a tree is too large to useonly one cut for the backcut, the

following method can be used. It iscommonly known as “quarter cutting”.

☛ Assess the lean and weight of thetree and cut the scarf in thenormal manner.

☛ Either draw your plan of work onpaper or mark the felling cutswith a paint bomb so that youcan work with confidence.

Felling a large tree.

☛ Select the side of the tree onwhich the first part of the backcutwill be made. If the tree has aslight lean, or if there is rot orsomething in the head that coulddislodge as the tree falls, makethe first part of the backcut fromthat side.

Holdingwedge

Scarf

Hingewood

Safe side

Cut 2 Cut 1

22 TREE FELLING

☛ Take the first backcut up to thehingewood. Place and tap homea holding wedge in the cut.

☛ Saw the second part of thebackcut up to the hingewood,using the top of the bar.

This method of felling helps tomaintain the hingewood across the fullwidth of the stump.

Always finish the second cut from thesafe side.

23TREE FELLING

Bottom cut of scarfhas been made toodeep, leaving noholding wood. Treewill fall without controland may “barberchair”.

Backcut at same levelas scarf may result intree kicking back offthe stump.

Backcut overcutmay result in wrongfall direction and bardamage.

Backcut below scarfincreases possibilityof tree sitting back.

Cut has been allowedto carry on leaving noholding wood orhinge. Tree will fallwithout control.

Backcut made toofar above scarf.

☛ HAZARD WARNINGSome Dangerous Practices

24 TREE FELLING

AdditionalTechniques

TREES with a small sideways lean,or a slight lean away from the

desired direction of fall, can be felledwhere desired by using the techniquesoutlined below.

Remember, if the tree has a largesideways lean or is leaning heavilybackwards, these techniques will notbe successful and may even provedangerous. Get an experiencedperson or professional to handle thistype of tree. A different method offalling may be required.

The methods explained below involvethe use of driving wedges.

USING WEDGESHigh-density plastic wedges and amallet or suitable driving tools arerequired.

☛ Remove the bark from the wedgeposition so that solid wood isexposed and the wedge isimmediately effective.

☛ Drive the wedge home as thefelling cuts proceed so thatmaximum assistance is obtainedfrom the wedge’s leverage.

☛ Don’t attempt to drive a plasticwedge into a closed cut assplitting or shattering of thewedge can cause facial injuries.

25TREE FELLING

Let‘s look at methods of felling treeswith side lean and those that areleaning back so that they are assistedto the desired direction of fall.Remember to have all the equipmentyou will require before starting anycuts.

TREES WITH SIDE LEAN☛ Make the scarf facing the desired

direction of fall.

☛ Start the backcut on the leaningside of the tree, leaving slightlynarrower hinge wood thannormal.

☛ Put the wedge in the cut.

☛ Continue the backcut from theother side, allowing for widerhingewood, and tap the wedge inas the cut takes place.

☛ Drive the wedge home when thecut is complete. The tree shouldfall in the desired direction.

Felling against natural lean.

Direction of fall

Directionof lean

Cut 1Cut 2

Hingewood

Scarf

26 TREE FELLING

TREES THAT ARE LEANING BACKThere are two methods of dealing withtrees that are leaning back from thedesired direction of fall. Rememberthat wedges are limited in changingthe direction of fall.

The Standard Method☛ Cut the scarf as normal in the

desired direction of fall.

☛ Backcut as normal.

☛ As soon as there is sufficientsolid wood, insert the wedge orwedges in the cut and drive in asthe cut progresses.

Felling a tree against the lean.

Split Level BackcutsThis method is particularly effective onsmaller trees as it allows for the wedgeto set when there is still a largeamount of holding wood present.

☛ Make the scarf slightly shallowerthan normal (but still one-quarterof the diameter) in the normalmanner.

Backcut

Scarf

Saw

Wedge WedgeLean

27TREE FELLING

☛ Make one side of the backcut inthe normal manner and set thewedge in this cut opposite thescarf and in line with the desireddirection of fall.

☛ Make the final part of the backcuttilting it down to avoid the wedge.

☛ Keep the wedge driven up as thefinal cut is made. Use anotherwedge if necessary.

☛ Make sure both backcuts areslightly overlapped but be surethey are still the correct distance(one-tenth of the diameter) abovethe joined scarf cuts.

Split level backcuts.

Tilted finalcut

First backcutwith wedgedriven

Hingewood

Tilted finalcut

Wedge

NOTE: Bothbackcuts must beabove where thescarf meets cut

Intendedfellingdirection

Directionof lean

28 TREE FELLING

Some Felling HazardsAnd Difficulties

THE following tips will help you toidentify and assess hazards and

difficulties when felling trees.

☛ Felling uphill. Be aware that thetree may slide back or kick upinto the work area once it hits theground. Move quickly along theescape route to distance yourselffrom the stump area. Don’t turnyour back — watch the path andprogress of the tree you havefelled.

☛ Felling trees across slope.Make sure you are not in the pathof a rolling tree. Move back alongyour escape route away from thefalling tree.

☛ Spars (trees with no tops).Make the scarf slightly deeper butnot over half the diameter. Placea wedge in the backcut as soonas practicable to ensure thecorrect direction of fall as there isno crown to assist in tipping thetree.

☛ Trees scarfed and backcut butnot on the ground.

These are of two types, known as“cut-up” and “hung-up” trees.

29TREE FELLING

CUT-UP TREEThis is where the tree sits back on thebackcut. It can result from misjudgedlean, failure to place a wedge in thebackcut or perhaps a gust of wind.

☛ If a machine is present, it canassist to push the tree in thedesired direction.

☛ Otherwise, wedges can beinserted in the backcut anddriven home until the tree falls.

☛ If the backcut is too tight forwedges to be inserted, you canrescarf and backcut the tree inthe reverse direction. Make thesecond lot of felling cuts thediameter of the tree above thefirst as this will reduce thepossibility of splitting. Insertwedges before there is anychance of the tree sitting backand keep them driven home asthe cut proceeds.

Seconddirectionof fall

Second scarf

First backcut

First scarf

Secondbackcut

Firstdirectionof fall

Method of making second lot of felling cuts.

30 TREE FELLING

HUNG-UP TREEThis is a felled tree that is preventedfrom falling to the ground by lodging inanother tree.

If a machine is present, the treeshould be brought to the ground.

Otherwise, use a canthook or leveringdevice to dislodge the tree.

If these two methods fail, seekassistance. Bring in a suitablemachine to assist or contact anexperienced feller, who will be familiarwith methods of dealing with thesituation.

31TREE FELLING

☛ HAZARD WARNING

“Hung-up” and “Cut-up” Trees

Never move forward within two treelengths of the intended direction offall of any “hung-up” or “cut-up” tree,or the direction of fall of a “hung-up”tree.

Where a tree is “hung up” or “cut up”tree it must be brought to the groundbefore you continue any other work.

Do not leave such trees unless youhave marked the area while you seekassistance, or someone else ispresent to warn other people of thehazard. Never leave “hung up” or“cut up” trees over a lunch or smokobreak or overnight without taking theabove precautions.

Hung-up trees

32 CROSS CUTTING

Preparing ForCrosscutting

NOW you have your tree safely onthe ground, you must prepare it

for crosscutting into lengths, whetherfor fencing or farm material, saw orpulp logs, firewood or simply fordisposal.

Before any work is done on the felledtree, examine it to see if any hazardsexist.

☛ If there are any trees that wereadjacent to the felled trees, givethem a quick check — there maybe broken branches orsuspended material that could fallinto the work area.

☛ Make sure the tree is stable andwill not roll or move when youstart to work on it. Place chocks ifyou think movement is possible— especially on slopes.

☛ Always finish the cut from theuphill side of the log.

☛ If you have the equipment, treeslying in difficult or dangerouspositions should be pulled into asafe and stable position beforetrimming or crosscutting isstarted.

33CROSS CUTTING

Tips For SafeTrimming

TRIMMING should be carried outwhile walking alongside the tree,

provided the tree is stable and debrisor scrub are not a hindrance.

☛ If trimming has to be done fromthe top of the log, the distance tothe ground should be no greaterthan 1.5 metres. This method oftrimming can cause back strainand result in falls and trips.

☛ Trees that are actually on theground can be trimmed withrelative safety. Beware of a treesuspended by its branches as onelarge branch may hold the treeup. Cutting this branch can resultin the tree rolling on top of you.

☛ When a tree is held up off theground, trim the large branchesfrom the outside in by making acouple of cuts to test the stability.

Trimming a tree held off the ground.

First cuts

Third cutsSecond cuts

34 CROSS CUTTING

☛ Always work on the uphill side ofa tree on a slope.

☛ Use enough bar when trimming tolessen the chance of nose or barcontact and the resultingkickback.

☛ Watch for limbs that are undertension. These can spring backand inflict severe injury. Standon the side away from the tensionand release the tension with twocuts — first on your side and thenon the other side.

35CROSS CUTTING

Techniques ForCrosscutting

WITH your tree trimmed andstable, you are now ready to start

crosscutting it into desired lengths.Make sure you have your wedges anddriving tool with you.

☛ Examine the tree and determineif any portion is liable to roll,drop or swing when the cut iscompleted.

☛ Don’t crosscut logs that aresuspended more than 1.5 metresabove the ground. Crosscuttingabove this height means the sawis being used above shoulderlevel. Log control can also belost as logs twist or roll.

☛ If it’s not obvious what is holdinga tree on a slope, you shouldassume that it may move at anytime. Work out of the dangerarea. Make sure others are notendangered if the cut log rollsdown the slope.

☛ Never attempt to crosscut a treeor log that is in a dangerouscondition or if the cut cannot becompleted. It may be possible tomake a cut in a less desirableposition that could eliminate thedanger.

☛ When about to crosscut, get afirm footing and avoid standing

36 CROSS CUTTING

on any loose material. Clear asufficient area to operate in and apath to escape if danger occurs.

☛ Look for any defects such as rotor large branches that may affectyour crosscutting.

☛ Make sure the carry-through ofthe saw does not bring the chaininto contact with the ground orobjects that may damage it.

☛ Mostly the tree will not be lying inan ideal position for crosscuttingand the following points willassist you to have trouble-freecrosscutting. The most commonsituations are tension,compression and end pressure.

TENSION AND COMPRESSIONThis can occur as top, bottom or sidetension and compression. Follow thecutting sequences outlined below fortrouble-free crosscutting.

Crosscutting a log under suspension(top compression and bottom tension).

2

5

Wedge cut

Smalltree

1

2

Large tree

13

4

37CROSS CUTTING

2

4

Large tree

Small tree

Sidetension

1 2

4

Large tree

31

2

Small tree

Crosscutting an overhung log (top tensionand bottom compression).

Crosscutting a tree with side tension.

Wedge cut

3

1

38 CROSS CUTTING

CROSSCUTTING A LARGE TREE

Crosscutting a large tree.Shift sides to make cut no. 3.

Return to original side for cut no. 4.☛ HAZARD WARNING

END PRESSUREA tree on a slope can create difficultieswhen it is directly up-slope as itsweight tends to close the saw cut.

3 Wedge

3 Wedge

4

1

3

12

4

2

Large treeSmall tree

1

2

Cutting a tree when end pressure exists.

39CROSS CUTTING

Second angle cut

First up cut

Windthrow Trees with Rootplates

☛ HAZARD WARNING

Windthrown trees that have therootplate or rootwad still attachedrequire special treatment. Whencrosscut, the rootplate can springback to its original position and thelog can move sideways towards thecrosscutter.

Rootplate sitting back as tree is crosscut.

Butting off a tree that may springupwards and sideways.

40 CROSS CUTTING

A similar situation can occur assections are cut off the tree until therootplate counterbalances the tree andsprings back into its original position.

Change of balance as sectionsare cut off.

☛ Never allow people to standwhere they would be in danger ofa rootplate springing back.

☛ Never stand on and cut trees thathave the rootplate still attached.

☛ HAZARD WARNING cont.

41CROSS CUTTING

SECTION TWO:

ADVANCEDTECHNIQUES

FOREXPERIENCED

PEOPLE

42 ADVANCED TECHNIQUES

Felling HeavyLeaners

TREES with a heavy lean developenormous tension on the upper

side away from the lean. Usingconventional felling with a scarf andbackcut can result in the tree splittingjust after you start the backcut or asthe backcut advances.

The tree’s splitting will form a “barberchair”. You lose control and there’s arisk of the tree sliding back into thework area.

Tawa and willow are two species thatare notoriously liable to splitting.

Tree splitting to form “barber chair”.

43ADVANCED TECHNIQUES

To overcome splitting, you can followthese steps:

☛ Place the scarf in the normalmanner.

☛ Make a bore cut, leaving aholding strap.

☛ Make the back final cut as low aspossible.

Method of overcoming splitting.

☛ The amount of forward leandictates the distance between thebackcuts. The greater the lean,the greater the distance.

1 Scarf

2 Bore and cut back,leaving holding strap

3 Final cut aslow as possible


Trees with More ThanOne Leader On Trunk

WHEN a tree has divided andgrown in different directions,

whenever possible each leader shouldbe fallen separately in the direction ofits lean.

If the dividing point of the leaders isclose enough to the ground to bereached safely:

☛ Put a normal scarf in the firstleader, facing the direction of thelean.

☛ Bore in behind the scarf at thecorrect height, leaving the correctwidth of hingewood, and cuttowards the dividing point of theleaders.

☛ When the first leader is safely onthe ground, the remaining onecan be fallen normally.

☛ Cut the stump off at groundlevel.

Lean

Lean


Lower scarf

If the dividing point of the leaders istoo high to be reached safely and thetwo leaders are reasonably verticalthey may be fallen as one if the joindoes not come close to the stumparea. In this instance:

☛ Put in a scarf deep enough andwide enough to cover bothleaders. It must be made in solidwood without a join or faultlinerunning through it.

☛ From the safest position, makethe backcut cutting evenlytowards the hingewood.

☛ If necessary, use wedges toensure that both leaders startfalling together.

Remember: Always fully assessdifficult trees before making anyfelling cuts and use the safestmethod possible.

Lean


Winches AndWire Ropes

CERTAIN standards must bemaintained if trees are going to be

back pulled by winches and wireropes. Make sure your equipment ischecked on a regular basis and isadequate for the job in hand.

Here are some guidelines and advice:

WIRE ROPES☛ Ropes must be of sufficient safe

working load (SWL) to handle thejob in hand.

☛ Do not use knots in any wirerope.

☛ Wire rope that is corroded, hassigns of kinking or stranded wiresor has been burnt should not beused.

☛ Eye-to-eye splices should not beused in any pulling rope. Joiningwith splices considerably reducesthe rope’s safe working load.

EQUIPMENT☛ Check that the blocks, shackles,

clamps, winches or any otherequipment to be used is in first-class order — your life coulddepend on it.


☛ Only use “D” shackles with securepins. Do not use open-sided “C”hooks.

☛ Equipment used should havebeen tested and marked with thesafe working load (SWL).

☛ As a guide, any equipment usedshould be 1.5 times the SWL ofthe pulling rope.

WINCHING☛ Before any work begins, discuss

fully with your colleagues whatyou intend to do. Winch andmachinery operators must knowwhat is required in relation to linetension and pulling speeds.

☛ Work out your visual and vocalcommunication before you startthe work.

☛ Use sound stumps of sufficientsize for the job in hand.

☛ Strops used on stumps should be1.5 times the SWL of the pullingrope and should be notched in sothey do not come off.

☛ Machines used must havesufficient weight and winchingpower to control the tree to befelled. They should be equippedwith a canopy that will protect theoperator from roll over or fallingobjects.


BackPulling

BACK pulling is the term used whenpulling trees away from their

natural lean. It is done to avoid treesdamaging property or falling into anarea in which they will be difficult toprocess, such as into a gully or over abank.

☛ Make sure all the equipment youneed is on site.

☛ Secure the rope as high aspracticable on the tree. Thehigher the rope, the easier it willbe to control the direction of thetree’s fall.

☛ Do not allow inexperiencedpeople to do the felling, or tooperate machines or winches.

☛ Carefully read and follow theadvice in the preceding “Winchesand Wire Ropes” section.

☛ Follow the felling techniquesoutlined in Section One of thisbooklet. Do not take shortcuts ordeviate from established fellingmethods.

☛ Never allow people to work orstand “in the bight” of anoperating rope.


☛ Never allow machinery or peoplewithin two lengths of the treesbeing felled in case there’s amishap and the trees fall in otherthan the planned direction.

METHODS FOR DIFFERENT SITUATIONSLet’s look at methods suitable fordifferent situations. The mostcommon is a direct pull with the winchor machine further away than two treelengths.

Direct pull with the winch or machinefurther away than two tree lengths.

“In the bight” of an operating rope.

Block

“Inthebight”

Winch

Tree

TreeWinch

More than twotree lengths

Scarf

Hingewood

Pull LeanBackcut


☛ Scarf the tree in the normalmanner but opposite the lean.

☛ Tension the rope to hold the treein position.

☛ Backcut the tree in the normalmanner, ensuring adequatehingewood is retained. Usewedges to hold the cut open ifnecessary.

☛ Retire to a safe position andsignal the pull to commence.

☛ Pull slowly at first, then increasespeed until the felling cuts takecontrol.

If you cannot get two tree lengthsclearance to the winch, there are twosafe methods which you can use inmore confined spaces.

The first method relies on the use ofsuitably located stumps. This methodpositions the winching equipment andoperator in a safe position and allowsgood vocal and visual contact.

The layout required is shown below:

Method relying on the use of suitablylocated stumps.

Winch

TreeBlock

Stump


Scarf

Holding wood

Felling procedure.

The felling procedure is:

☛ Scarf and start the backcut to thedirection of pull in the normalmanner, holding more wood awayfrom the lean.

☛ Begin the pull and continue thetension as the backcut continuesand until the felling cuts takecontrol.

The second method allows you toback pull the tree in the confinedspace without stumps being present.The layout is illustrated below:

Method for back pulling the treewithout stumps being present.

Pull

Lean

Backcut

Machineor winch

Lean

Scarf


Felling procedure.

☛ Drive the machine out at about80° opposite to the lean.

☛ Tension the rope to hold tree inposition of fall.

☛ Scarf and backcut in thedirection of the planned fall,holding more wood opposite thelean.

☛ The tree will free fall, swinging onthe rope with no danger to theoperator or equipment.

Pull

Lean

Fall


TreeDriving

THE term “driving” means pushing atree over by felling another tree

into it. Tree driving can be used in thefollowing situations:

— To take down a tree that has onlypartially fallen and is eitherlodged against or caught in thebranches of another tree.

— To drive a standing tree that has aslight back lean away from thedesired direction of fall.

— To drive a tree that has sat backon the cut.

— To drive a tree into a morefavourable position forprocessing.

Follow these steps for successful andtrouble-free driving:

PREPARATION☛ Ensure people are well clear of

the area. Remember the two-treelength clearance applies to boththe driving tree and the tree to bedriven.

☛ The driving tree must be ofsufficient size and weight to makethe drive successful.


☛ Don’t make any cuts in thedriving tree at this stage.

☛ Choose a drive tree that has agood angle —

no more than 20°

off the proposed direction of fallof the tree being driven.

TREE TO BE DRIVEN☛ Clear the escape route and your

work area.

☛ Scarf the tree to be driven in thenormal manner. Take up thebackcut, and at the earliestopportunity insert a wedge anddrive it home as the cutproceeds. Stop the backcut sothat sufficient wood is held tohold control of the tree.

☛ If the tree to be driven is leaningand lodged in another tree, donot go under it or forward of it tosee why it didn’t fall to theground.

☛ Be aware of any debris, deadbranches or material in either thedriving tree and tree to be driven.This material may be thrown backinto the work area at impact.

DRIVING TREE☛ Never use a dead tree as a drive

tree or drive onto dead trees. Onimpact, pieces can fly in alldirections.

☛ Take extra care with the scarf andbackcut of the driving tree as anindirect hit may result in the treeto be driven swaying back and


falling into your work area, orpieces or branches breaking offand being thrown around.

☛ As the driving tree falls, removeand shut off the saw, take theescape route and watch for anydislodged or flying material.

☛ If you are driving a leaning orloaded tree, watch for the drivingtree sliding down the leaning treeand kicking across into the workarea.

☛ If the drive is unsuccessful andtrees are hung-up, mark off thearea and get a machine to finishthe work.

HAZARD WARNING


☛ HAZARD WARNINGTree Sitting Back on Stump

If you intend driving a tree that has satback on the cut, or a tree that is “cut-up” (scarfed and backcut) and held bywedges, take extreme care.

A small gust of wind can cause thetree to fall into the work area. Neverturn your back on a cut-up tree.

Face the cut-up tree while makingyour scarf and backcut in the drivingtree.


Working InWindthrow

SECTION one of this booklet described how to deal with single

windthrown trees. This part coversworking in areas of windthrow.

In windthrow areas, normal hazardsare multiplied by the presence ofbroken or shattered trees and varyingdegrees of tension due to the treesbeing interlocked, bent and partiallyfallen.

Approach each tree with caution.Examine the tree to see which way thetension lies — whether up, down orsideways — and determine the correctmethod of work.

Butting a tree under tension.

Cutterbarprotectedby stepCut 4

Cut 4

Cuts 1, 2, and 3

Tension

Tensionreleased

Cut 2

Cut 3

58

☛ Extreme care is necessary indealing with bent or leaning trees.If there’s a machine present, itcan be used to uproot the treeand reduce the hazard.Otherwise, follow the guidelinesgiven in this booklet for dealingwith this situation.

☛ Random lays with interlockingstems create special hazardsbecause of bending and tensionscaused by the interlocking.Carefully examine these and workout the sequence of cuts requiredto release the tension in a logicaland safe manner.

☛ Watch for rootplates springingback once the counterbalance ofthe tree is cut off. Use the cutillustrated below. Note the shiftof cutting positions.

Butting off a tree that may springupwards and sideways.

☛ Always be aware of brokenmaterial that may move or bethrown around as you butt offtrees or make cuts to logs undertension.

First upcut

•First

position

•Secondposition

ADVANCED TECHNIQUES

Second angle cut

59

☛ Many branches are under tensionin windblown areas. Stand on thecorrect side, release the tensionand then complete the cut.

☛ When felling trees without tops,increase the scarf distance andinsert a wedge as soon aspossible to help guide the fellingdirection.

ADVANCED TECHNIQUES

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