Safe Practice Guide - IHSA

Line Clearing Operations

Safe Practice Guide

ihsa.ca

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Infrastructure Health & Safety Association

Safe Practice Guide

Line Clearing Operations

Foreword

This Guide designates the practices that should befollowed by the member firms of the InfrastructureHealth & Safety Association (IHSA) when involved inoverhead line clearing operations. This Guide is notdesigned as a training manual, but contains informa-tion, best practices and general recommendationsdeemed appropriate to perform a job in a responsibleand safe manner.

The contents of this Safe Practice Guide, including alladvice, recommendations and procedures, areprovided as a service by the Infrastructure Health andSafety Association. No representation of any kind ismade to any persons whatsoever with regard to theaccuracy, completeness or sufficiency of the informa-tion contained herein. Any and all use of or reliance onthis Safe Practice Guide and the information containedherein is solely and entirely at the user's risk. The useralso acknowledges that the safe practices describedherein may not satisfy all requirements of Ontario law.

The Infrastructure Health & Safety Association wishesto express its appreciation to those who assisted inthe preparation of this Guide.

09/08

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TABLE OF CONTENTS

INTRODUCTION 7

PURPOSE 7

DEFINITIONS 8

SECTION IGENERAL

100 Safe Execution of Work 12101 Competent Personnel 12102 Job Planning 12103 Work Methods 13104 Teamwork 24

SECTION IIBASIC ELECTRICITY FOR FORESTERS

200 Introduction 26201 The Nature of Electricity 26202 Units of Electricity 28203 Types of Electrical Contact 29204 Step and Touch Potentials 30

SECTION IIIJOB PREPARATION

300 Job Considerations 34301 Suggested Tools and Equipment 34302 Daily Inspection and Maintenance

of Tools and Equipment 39303 Work Area Protection 46304 Tailboard Talk 46305 Utility Work Protection Code 47

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SECTION IVAERIAL DEVICES, BOOM TRUCKS, CRANES

AND EXTENSIBLE BOOM PLATFORMS

400 Daily Vehicle Checks 50401 Vehicle Setup 51402 Holding Valve Check 53403 Securing for Travel 56

SECTION VTREE INSPECTION

500 General 58

SECTION VITREE PRUNING

600 General 60601 Types of Pruning 61602 Pruning Clearances 62

SECTION VIITREE CLIMBING TECHNIQUES

700 General 66701 Crotch/Branch Union Selection 66702 Friction Hitch and Termination

Knot Selection 69703 Ascending Rope Assisted on a

Conventional (Closed) Climbing System 75704 Ascending With Climbers (Spurs) 80705 Formula for the Forces Created 80706 Climbing Using a Portable Ladder 82707 Manoeuvering in the Tree 84708 Positioning/Tying In 85709 Double Positioning 85710 Descending the Tree 86711 Repositioning 87

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SECTION VIIIWORKING NEAR ENERGIZED CONDUCTORS

AND APPARATUS

800 General 90801 Working Above the Level of

Energized Conductors 92802 Limb Removal in Proximity to

Energized Conductors 93803 Removing Limbs from Conductor Contact 94

SECTION IXTREE REMOVAL

900 Safe Practices for Tree Removal 96

SECTION XSAFE LIMITS OF APPROACH

1000 General 100

SECTION XISAFE CLEAN UP PROCEDURES

1100 Safe Procedures for Use ofBrush Chippers 104

1101 Stump Removal 1081102 Hauling of Brush 1091103 Work on Customer Premises 1101104 Tool Clean Up 110

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References

1. IHSA:- Rule Book, Electrical Utility Safety Rules (EUSR)- Safe Practice Guide, Hydraulics- Safe Practice Guide, Rescue Techniques- Crane Handbook and Mobile Crane Handbook

2. Occupational Health and Safety Act: Ontario Regu-lations for Construction Projects (OHSA)

3. Ontario Natural Resources Safety Association(ONRSA):- The Cutting Edge Handbook

4. Ontario Hydro:- Forestry Manuals and Forestry Trade Handbook

5. Ontario Shade Tree Council:- Arboricultural Specifications

6. Friction Hitch and Termination Knot Testingdocument - February 1, 2006

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Safe Practice Guide

LINE CLEARING OPERATIONS

INTRODUCTION

Of the many facets to forestry work, line clearingoperations involves considerable risk. The risk is duein part to the type of work involved as well as the overallenvironment. This type of work should be performedfrom an aerial device; however, it may also requiretechniques from the body of a tree. The environmentinvolves working near energized electrical conductorsand other apparatus. Working around both requiresthe use of trained and knowledgeable individuals.This Guide will attempt to define the basic line clearingoperation requirements, however, nothing replacesknowledge, training and experience.

PURPOSE

The fundamental purpose of this Guide is to assistworkers who are, or may be, involved in forestry work.The contents should be used to help establish aprocedure to create a safe work environment forworkers involved in tree trimming, tree removal, lineclearing, and may require additional training.

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DEFINITIONS

Apparatus All equipment pertaining to thegeneration, transmission, distribu-tion and use of electrical power.

Authorized A worker who has been given formalWorker(s) permission by the owner and employer

and is competent to perform work inproximity to equipment energized atvoltages greater than 750 V nominal.

Competent A person who:Person a) is qualified because of knowledge,

training and experience to organizework and its performance;

b) is familiar with the provisions of theOccupational Health and Safety Actand the Regulations that apply to thework; and

c) has knowledge of any potential oractual danger to health or safety inthe workplace.

Controlling The person(s) who occupies aAuthority position responsible for performing,

directing or authorizing changes inconditions or position of the specificapparatus or devices.

De-energized Where electrical energy has beendischarged through a mechanically-secure connection to an effectiveground potential.

Energized Capable of delivering energy by reasonof being dynamically alive or charged.

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Isolated Separated from all sources of dynamicenergy.

Proximity Refers to the following distances fromenergized electrical apparatus,a) within 3 m (10 ft.) from

energized apparatus above 750 V to150 kV;

b) within 4.5 m (15 ft.) fromenergized apparatus above 150 kV to250 kV; and

c) within 6 m (20 ft.) fromenergized apparatus above 250 kV.

NOTE: "Proximity" does not apply toapparatus that is designed, built andinstalled to be intrinsically safe forhuman touch.

Supervisor A person who has charge over aworkplace or authority over a worker.

Worker(s) A person who performs work or sup-plies services for monetary compensa-tion.

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SECTION I

GENERAL

100 SAFE EXECUTION OF WORK

101 COMPETENT PERSONNEL

102 JOB PLANNING

103 WORK METHODS

104 TEAMWORK

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SECTION IGENERAL

100 SAFE EXECUTION OF WORKThe safe execution of line clearing operations requires:- hazard assessment- competent personnel- job planning (documented)- detailed rescue plans and open communication with the controlling authority- work methods- teamwork

101 COMPETENT PERSONNEL

1. Only competent personnel or personnel in trainingunder the direct supervision of a competent personshould attempt line clearing operations.

2. Personnel attempting line clearing operationsshould have been previously instructed or be underinstruction in the proper use of the technique in-volved. All work should be carried out on a "goslow" basis until personnel become proficient inthis technique.

3. Only personnel who have been instructed in theirproper care and use should work from insulatedaerial devices.

102 JOB PLANNING

As in all other phases of forestry work, documented jobplanning for line clearing operations is of primeimportance, so that the work may be performed safelyand efficiently. All workers should be involved.

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103 WORK METHODS

Only competent personnel or personnel in trainingunder the continuous direction of competent personnelshould be assigned to perform line clearing opera-tions in proximity to outdoor transmission and/ordistribution electrical systems as per the OccupationalHealth and Safety Act (OHSA) Construction Regula-tions.

Prior to work commencing, the supervisor of the lineclearing crew is required to notify the power authority ofthe work location and is required to acquire workprotection on lines and/or apparatus.

Protection for work

1. Employees involved in forestry work in proximity tolive lines or apparatus should be governed by theUtility Work Protection Code (UWPC) or equivalent.

2. Employees are legislated to acquire hold-offs, workpermits, or other forms of guaranteed protection asdetermined by the supervisor and crew.

3. When it is necessary to isolate a circuit for lineclearing operations, the circuit should also be de-energized by the local controlling authority.

Working aloft

1. (a) No employee should work aloft in trees withouta second employee in attendance.

(b) The second employee should be competent toeffect in rescue operations.

2. Trees should be closely inspected prior to climbingto ensure that branches will support the climber’sweight and also to ensure the location of energizedconductors does not pose a hazard.

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3. Suitable fall protection should be used whenworking aloft.

4. When changing work locations aloft usingrecrotching procedures, a means of fall protectionshould be maintained at all times.

Conditions under which work should be suspended

Work in trees shall not be started or, if in progress,shall be suspended under the following conditions:

(a) during electrical storms in the vicinity; or

(b) when, in the opinion of the supervisor, the weatherconditions make the job hazardous.

Felling trees

1. Trees should be felled away from power ortelecommunications lines after limbs, which couldcontact the line or cause damage to other trees orproperty, have been removed. When it is neces-sary to fell a tree toward power or telecommunica-tions lines, the tree should be topped low enough toclear all conductors, poles, guys etc.

2. Trees should not be pulled down by ropes con-nected to moving vehicles.

3. Guy ropes, felling bars and wedges should be usedwhere necessary to control the direction of fall.

4. Anchors for guy ropes should be installed in alocation that allows employees handling the guyropes to stand well outside the striking distance ofthe tree.

5. Persons other than those actually engaged incutting the tree should keep clear of any area withinpossible striking distance of the tree.

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6. Cutters should establish a suitable escape pathprior to felling a tree, shall give ample warningwhen a tree is about to fall and should stand clearof the butt while the tree is falling.

7. Partially cut trees should be felled prior to vacatingthe work area.

Lowering severed branches from trees

1. A crotched (or otherwise attached) rope should beemployed to remove branches from above ener-gized conductors where necessary. Avoid shockloading any trees.

2. Cutters should give ample warning before a limb orstub is dropped.

3. Branches should not be allowed to fall on, or makecontact with, energized conductors.

4. Severed branches (hangers) should be removedfrom a tree prior to vacating a work area.

Use of safety rope

Safety ropes used for work aloft should be suitable forthat purpose and the following rules should apply:

(a) Climbers should establish that ropes are set in anappropriate anchor union. Friction hitches shouldbe safely tied and safety saddles should beproperly adjusted prior to commencing work aloft.Ropes should not be used for descent with thefriction hitch untied.

(b) Ropes should be anchored in a tree at a point awayfrom any live circuit to prevent employees fromswinging or falling into live conductors. The workershould maintain two points of attachment whileclimbing.

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(c) When working in areas frequented by the public,the free ends of ropes should not be allowed todangle on or near the ground and should be keptfree from debris.

(d) Climbers should keep climbing ropes taut at alltimes when working in trees.

(e) The entire length of climbing ropes should be givenclose inspection each day prior to use.

(f) Climbing ropes should not be used for loweringbranches or guying trees.

(g) Climbing ropes should be of sufficient length toreach the ground safely.

NOTE: Polypropylene and natural fibre ropeshould not be used as safety ropes. Theminimum requirement for safety ropes is 12.7mm (1/2 in.) diameter nylon or other durablematerial of equivalent impact strength andelasticity.

Use of portable ladders

1. Non-conductive fibreglass ladders with non-slipbases should be used in line clearing operations.

2. Trucks or other moveable objects should not beused to support portable ladders.

3. Portable ladders should be secured at the top orbottom, or both, if there is a danger of the ladderslipping or falling.

4. Ladders should be removed from trees when not inuse.

Handling tools and equipment

1. Employees should carry only their safety saddleand climbing rope, including lanyard, when faced

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with a long or difficult climb and should be tied infrom the ground before ascending.

2. A rope or tool bag should be used for passing toolsand material to or from employees aloft. Under nocircumstances should tools and material be thrownaloft.

3. When not in use, handsaws should be fastenedsecurely to the employee’s belt or saddle. When outof use temporarily, all pruners or pole saws shouldbe hooked securely over a limb of sufficient strengthto carry their weight. Under no circumstancesshould pruners or pole saws be hung on a conduc-tor.

Chainsaws

1. A gasoline-powered chainsaw should be equippedwith an anti-kickback chain or device and a chainbrake.

2. Only competent employees should be permitted tooperate chainsaws.

3. No one except the operators should be allowedwithin a radius of 1.83 m (6 ft.) of a chainsaw whenit is in operation except when it is used aloft in anaerial bucket device.

4. Chainsaws should not be used above the shoulderlevel of the operator.

5. A gasoline powered chainsaw should be heldfirmly when being started.

6. The motor should not be started until the chainsawis within the immediate work area.

7. The following further precautions should be ob-served when using chainsaws.

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(a) a guard should be installed on the chain whilewalking and carrying a chainsaw which is notrunning

(b) cutting chains should not be inserted in theguiderail groove while the motor is running

(c) chainsaws should be at suitable operatingspeed before the cut is started

(d) an approved safety container should be used forstoring gasoline and for refuellingchainsaws

(e) saws should be permitted to cool beforerefuelling

(f) smoking is prohibited while the tank is beingfilled

(g) employees should wear suitable eyeprotection while operating chainsaws

(h) employees should wear suitable legprotection when operating chainsaws exceptwhen working from a bucket of an aerialdevice

(i) employees should wear hearing protectionin accordance with legislative requirementswhen operating gasoline-powered chainsaws

(j) electric saws, cords and generators shouldbe handled with care and maintained andgrounded in a manner consistent with safework practices

(k) the motor of the chainsaw should be shut offwhen moving the saw from one location toanother, except where the trees are closetogether and the approach is unobstructed

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(l) where applicable, these rules should applyto the use of hydraulically-powered chainsaws

8. Chainsaws should not be used aloft in trees unlessthe saw is secured with a rope independent of theclimber’s rope.

9. The motor of the chainsaw should be shut off whenrepositioning an aerial device.

Work near energized conductors

1. Only competent persons and/or persons in training,under the direct supervision of a competent person,should work in proximity to energized conductorsabove 750 volts.

2. Communication should be maintained at all timesbetween the power supply authority and lineclearing crews performing work in proximity toenergized conductors above 750 volts.

3. If needed and where practical, climbing should bedone on the side of a tree farthest from energizedconductors.

4. Under no circumstances should employees climbbetween energized conductors.

5. Branches to be removed in proximity to energizedconductors should be pruned or cut into shortlengths where practical, or should be removedusing accepted rigging and hosting methods (seeRopes, Rigging and Slinging Hardware SafePractice Guide).

6. Should a limb still attached to a tree be found incontact with a conductor energized above 750 volts:

(a) the tree should not be climbed directly from theground

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(b) clearing should be done using live line equip-ment from the ground, from an aerial deviceor portable non-conductive ladder

(c) the circuit should be isolated and de-energizedprior to limb removal

Pole pruners

When working in proximity to conductors energizedbetween 750 volts and 50,000 volts phase to phase:

(a) suitable, well maintained, non-conductive polepruners should be employed

(b) pole pruner ropes shall be equipped with insulatedinserts

(c) pruners (frp) should be tested as specified in theElectrical Utility Safety Rules (EUSR)

Removing limbs from conductor contact

1. The controlling authority should be notified immedi-ately.

2. Should a limb fall from a tree and become lodgedon one or more conductors, employees shouldmaintain adequate clearance in the event ofconductor burn off.

3. Insulated pole pruners and rubber gloves shouldbe employed when removing limbs from conductorcontact.

4. When a limb is too large for pruners or a hazardoussituation exists, the circuit should be isolated andde-energized by the power authority or his agentprior to limb removal.

Aerial devices/cranes

1. When an employee is aloft in an aerial device, asecond employee should be available and compe-

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tent to effect a rescue.

2. Trucks should not be moved until aerial devices arein the stowed position.

3. Only one employee should work from an aerialladder and when a worker is aloft the position of theladder may only be changed when it is safe to doso.

4. When working from an aerial ladder or device,employees should be protected from falling by asuitable fall protection system securely fastened toan approved attachment on the aerial ladder ordevice.

5. When an employee is aloft in an aerial device, arope of sufficient length should be carried to raise arescue rope or controlled descent device if required.

6. Employees should not be allowed to remain in thebucket(s) of an aerial device during emergencylowering operations when pressure on the hydrau-lic system is being manually released.

7. Aerial devices (cranes included) should be oper-ated within:

(a) the limitations of the manufacturers’ specifica-tions

(b) the limits of safe approach (see Table #1)and current legislation

8. Aerial devices should be dielectrically retested asper current legislation.

9. Electrical testing of aerial ladder devices should bein accordance with the initial test for aerial laddersas shown in the most current Canadian StandardsAssociation (CSA) standard for Vehicle MountedAerial Devices.

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Safe Limits of Approach for Authorized Workers orWorkers Under Direct Supervision of an Authorized

Worker

Voltage Range Minimum(Phase to Phase) Clearance

750 to 35,000 0.9 m (3 ft.)

> 35,000 to 50,000 1.2 m (4 ft.)

> 50,000 to 150,000 1.5 m (5 ft.)

> 150,000 to 250,000 2.1 m (7 ft.)

> 250,000 to 550,000 3.7 m (12 ft.)

• Only authorized workers or workers under thecontinuous direction of an authorized worker mayapproach, work, or allow material or conductive toolsto approach exposed energized electrical apparatusto limits as stated.

• In planning the task to be performed, considerationmust be given to the worker’s position in relation tothe exposed energized apparatus such that plannedmovements of the worker’s body or conductive tools,material or vegetation will not result in any encroach-ment upon these limits.

10. The criteria for electrical testing of extensible boomtype aerial bucket devices and radial boom derrickunits with attached insulated booms and bucketsshould be tested under current legislation.

11. Aerial devices should be inspected for structural,mechanical and hydraulic defects at regular inter-vals, in accordance with existing legislation.

Table #1

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12. Aerial devices used to raise employees aloft inproximity to energized apparatus or equipmentshould be equipped with upper and lower controls.Lower controls should be capable of positivelyoverriding the upper controls as per current legisla-tion.

13. Aerial devices with upper boom insulation onlyshould be adequately grounded (preferably to thesystem neutral where available) or should beisolated with a suitable barricade erected aroundthem when the boom or arm is raised in proximityto energized apparatus operating above 750 voltsas per current legislation.

14. When two or more aerial devices are working at thesame location, the vehicles should be connected tothe same ground medium.

Mechanical brush saws

1. Mechanical brush saws should not be used aloft.

2. Persons other than the operator should maintain4.5 m (15 ft.) clearance from operating mechanicalbrush saws.

3. Suitable personal protective equipment (head, foot,eye, hearing, leg, etc.) should be used whenoperating mechanical brush saws.

Mechanical brush chippers

1. Prior to servicing a brush chipper, the motor ignitionswitch should be in the off position and the ignitionkey removed, or the chipper shall otherwise berendered inoperable.

2. Drums should be locked/blocked prior to mainten-ance procedures to prevent rotation and the blocksshould remain in place until maintenance iscompleted.

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3. Suitable personal protective equipment (head, foot,eye, ear) should be used when operating mechani-cal brush chippers.

4. Employees should not stand or walk directly in frontof the exhaust chute when a chipper is operating.

5. Employees feeding brush into a chipper shouldwear loose fitting gloves and shall stand to oneside of the feeder chute to prevent injury due tokickback.

6. Hands or feet should not be used to push brushpast the face of the feeder chute.

104 TEAMWORK

The best teams are made up of people who will workcompatibly with one another. Good communication isessential while the work is being performed.

Only when the preceeding requirements are met canthe job be carried out safely and efficiently.

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SECTION II

BASIC ELECTRICITY FOR FORESTERS

200 INTRODUCTION

201 THE NATURE OF ELECTRICITY

202 UNITS OF ELECTRICITY

203 TYPES OF ELECTRICAL CONTACT

204 STEP AND TOUCH POTENTIALS

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SECTION II

BASIC ELECTRICITY FOR FORESTERS

200 INTRODUCTIONThis Guide was developed to help you perform aparticular type of tree work known as line clearing. It isdifferent from all other kinds of tree work becauseelectrical conductors are almost always close by andyou must use special types of work protection to guardagainst accidental contact.

NOTE: There are other hazards associated withline clearing and corresponding safetydevices that should be used to protectyourself from them. This section will dealonly with electrical hazards.

To work safely in the line clearing trade, workers shouldhave a basic understanding of electricity. This willmake it possible to anticipate hazardous situations andwork to avoid them and/or protect yourself fromelectrical energy.

201 THE NATURE OF ELECTRICITYMany people have difficulty understanding the nature ofelectricity because it cannot be seen or heard. So let’scompare it to something more easily understandable awater system.

When describing the water system, we used the termspressure and flow. The comparable terms in anelectrical system would be voltage (potential differ-ence) and current flow.

In an electrical system, a battery or generator suppliesthe pressure which causes electricity to flow throughthe resistance of wires. If the switch is open, current

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will not flow. (See Figure #1) When the switch isclosed to complete a circuit and voltage is high, a lot ofcurrent will flow. When voltage is low, the flow ofelectricity will also be lower.

Figure #1

Series Circuit

It follows that a short length or large diameter wireallows more current flow while a long length or smalldiameter wire will do the opposite. Poor quality wirewill also restrict the flow. As in the water system, areturn path is necessary to complete the circuit. Let’scompare the two systems (see Table #2):

WATER ELECTRICITY

Unit Unit Quantity Measurement Quantity Measurement

Pressure Kilopascals Voltage Volts(pounds per (potential

square inch) difference)

Flow Litres per Minute Current Flow Amperes

(gallons per minute)

Restriction “C” factor Resistance Ohms(higher the number

the better the flow)

Conductor

Source(battery orgenerator)

Load(light bulb)

Switch

L

Table #2

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202 UNITS OF ELECTRICITYVOLTS is the measurement unit of electric pressure.Voltage levels are divided into two categories: second-ary and primary voltages. Secondary voltages varyanywhere up to 750 volts. For example, a typical housevoltage is 120/240. The 120 is voltage between theconductor and ground (neutral) while the 240 is thevoltage across the two 120 volt conductors.

Primary voltage is any voltage above 750 volts. Forexample, in many urban areas the primary voltage is16,200/27,600 volts. The 16,200 is voltage betweenconductor and ground (neutral) while the 27,600 isvoltage across two energized conductors.

Whenever utility personnel talk about primary voltage,they refer to a certain “kV”, as in 27.6 kV. This is theshort form of kilovolt (kilo meaning one thousand).Therefore, 27.6 kV is twenty seven thousand sixhundred volts.

NOTE: All line clearing operations in Ontarioutilities will be done around electricalcircuits of at least 120 volts.

AMPERES is the measurement unit for the flow ofelectricity. The severity of electric shock received ifcontact is made with an energized component willdepend on how much electricity flows through the bodyand what part of the body is contacted.

For example, current flowing through an arm willprobably affect only the arm and may not be serious.However, current flowing from hand to hand could killbecause the electricity will flow through the body’s vitalorgans. As little as one tenth (1/10) of one ampere canstop a human heart. To understand how little energythat is, consider that one half an ampere is all that isneeded to light a 60 watt light bulb. Certainly, any

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circuit around which you perform line clearing will havemuch higher amperage — more than enough to kill oncontact.

OHMS is the measurement unit for resistance of amaterial. Any material will conduct electricity to somedegree, but some are better conductors than others.All materials fall into one of three categories: insula-tors, conductors, semiconductors.

Insulators conduct so little electricity that it is often notdetectable. Typical insulators are glass, porcelain andrubber.

Conductors transfer electricity easily. Good conductorsinclude metals and, in some cases, the human body.

Semiconductors will conduct electricity, better or worse,depending on variables like moisture content andcontaminants. Examples of semiconductors are wood,rope and earth.

Remember: Electricity always seeks the easiest pathto ground and the human body is a reasonably goodconductor. Therefore, when resistance is low enough,any contact with energized apparatus can kill. Whenperforming line clearing work, don’t bridge yourselfbetween two conductors or between a conductor and aground (e.g. a tree). Because of low body resistance,current will flow freely through the body if it gets thechance.

203 TYPES OF ELECTRICAL CONTACTThere are two types of electrical contact: direct andindirect. Direct contact refers to touching an energizedcomponent with some part of the body. Indirect contactrefers to touching a conductive object which, in turn, istouching an energized component.

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204 STEP AND TOUCH POTENTIALSIf electricity is released into the ground surface, forexample, when a live wire is laying on the ground, theelectricity will fan out from the point of contact. Thereis a rippling effect, much like that produced when astone is dropped into a pool of water. This is known asvoltage drop or ground gradient and can create theproblems of step and touch potentials.

Figure #2 represents a possible ground gradientcondition, created when electrical energy comes incontact with the ground in the absence of groundelectrodes (ground rods) to safely conduct and dissi-pate the energy. Depending on soil conditions, it cantravel across the surface or close to the surface of theground. As the energy moves out from the source (abroken conductor, for example) a certain amount of

resistance is encountered at some point, creating avoltage drop. As a result, there is a difference ofpotential between the point where the voltage dropsand the source voltage. If the electrical pressure ishigh enough (primary voltage) a number of differentvoltage levels, or gradients develop.

Figure #2

step

touch step

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Whenever there is a difference of potential, current willflow through a conductive medium (path) between thedifferent potential levels. A person walking through thisground gradient condition could become an alternate/parallel path for current flow. This is referred to as"step" potential.

If a branch breaks off a tree, falls across an energizedprimary conductor, causing it to fall to the ground. If theconductor remains energized, the ground under it andthe ground nearby will also become energized, re-sulting in a ground gradient situation.

A worker who approaches and is unaware of thedanger that exists, could be subjected to fatal steppotential due to the difference of potential that couldexist relative to the worker's feet which, at some point,would be situated in different potential gradients. Thiscould then result in current flow entering one foot andexiting through the other. The path of current flowwould be through the lower part of the torso, which mayhave a harmful effect on the worker.

If there is a broken conductor lying on the ground, stayaway from it and keep others away from it as well.Contact the utility to make the necessary repairs.

The other situation of concern is "touch" potential. Thisoccurs when a person touches a conductive object,like a tree branch, which is also in contact with anenergized component, while another part of the body isat a different potential (touching another part of thetree). Let us suppose that, while working in a tree, aworker cuts a branch that falls on an energized primarycon-ductor. The worker (not wearing rubber gloves)reaches out and grasps the branch while it is still incontact with the energized primary conductor.

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The branch is also energized, but at a different poten-tial than the tree. By touching the branch, the workerhas bridged between the branch and the tree.

This could result in current flow from hand to footthrough the upper torso in the area of the heart andlungs, which could prove fatal.

Lookout for touch potential situations when you areworking in proximity to energized conductors. Usepersonal protective equipment and insulated tools andfollow proper work procedures.

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SECTION III

JOB PREPARATION

300 JOB CONSIDERATIONS

301 SUGGESTED TOOLS AND EQUIPMENT

302 DAILY INSPECTION AND MAINTENANCEOF TOOLS AND EQUIPMENT

303 WORK AREA PROTECTION

304 TAILBOARD TALK

305 UTILITY WORK PROTECTION CODE

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SECTION IIIJOB PREPARATION

300 JOB CONSIDERATIONS

1. Is your clothing appropriate for the season and thejob?

2. Do you have all of your personal protective equip-ment?

3. Do you have all other necessary equipment?

4. Do you have all the necessary tools?

5. Are your equipment and tools safe?

6. Have you properly prepared yourself by learninggood work practices and techniques?

7. Do you know the dangers and hazards of the job?

8. Are you ready to practice the correct methods andtechniques as you work?

301 SUGGESTED TOOLS AND EQUIPMENT

1. Personal Protective Equipment

A. Head ProtectionWear a CSA approved, Class "E" hard hat with ashell and a suspension that will protect the workeragainst impact, and will withstand a dielectricstrength test at 20,000 volts, phase to ground.

NOTE: The chemicals used in spraying opera-tions and bug repellant can deterioratethe hard hat material.

B. Eye Protection

(i) eye protection should be worn in the follow-ing circumstances

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- when working in, observing or supervisingan area or work site where there is apossibility of eye injury

- when operating chainsaws, chippers,brush saws or circular saws

- when pouring or mixing chemicals

- whenever there is a danger of foreign ob-jects or particles striking or entering theeye

(ii) Types of Eye Protection:- protective spectacles with side shields- cover goggles- full face screen that mounts on the hard

hat*- full face shield that mounts on the hard

hat** must be worn with spectacles or goggles

C. Foot ProtectionWear CSA approved safety boots with safetytoe caps and non-slip, impermeable soles. Ifworking with a chainsaw, on the ground, thetongue and sides of the boots should be linedwith ballistic nylon or Kevlar. Safety bootsshould have soft soles if climbing.

D. Hand Protection

Wear leather gloves for tasks such as climbing,pruning, picking up brush, chipping, etc., but notfor handling oils, chemicals or operating chain-saws.

Use chainsaw gloves or mitts when operating achainsaw. They have ballistic nylon or kevlarsewn into the back of the hand and thumb.

Use neoprene-covered cotton gloves whenhandling oils and chemicals.

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Use minimum Class 2 (20,000 volt) rubbergloves with leather protectors when you, or thetree or branch that is being trimmed or cut, iswithin 3 m (10 ft.) of electrical apparatus ener-gized between 750 and 50,000 volts.

E. Hearing Protection

The allowable exposure is 85 decibels for aneight hour period and once this is exceeded,using a factor of three, the exposure timedecreases by half (eg., 88 decibels - four hourexposure, 91 decibels - two hour exposure).Workers should be looking for a Noise Reduc-tion Rating (NRR) and follow manufacturer andlegislative requirements for their hearingprotection. It may be advisable to have noiselevel tests done "at the worker" to ensureappropriate protecton measures are in place.

F. Leg ProtectionLeg protection is a must when operating achainsaw, except when in the bucket of an aerialdevice. Leg protection has ballistic nylon orKevlar inserted or sewn into the leggings andcalves.

Types of leg protection include:- chainsaw leggings (chaps)- chainsaw apron- chainsaw pants

G. Protective ClothingClothing which is resistant to ignition and thepropagation of flame (FR) should be worn whenworking around energized apparatus. Shirtsmust have full length sleeves extending to thewrists.

37

H. Protective Clothing for SprayingWear the following protective clothes whenspraying:- neoprene coveralls- neoprene apron- neoprene jacket- neoprene overalls- neoprene boots

I. Fall Protection EquipmentWhere a worker could fall more than 3 m (10 ft.),an approved fall protection system which wouldprevent a fall greater than 1.5 m (5 ft.) and havethe capability of absorbing twice the energy andtwice the load generated by the fall, limiting themaximum arresting force to 8 kilonewtons(1,800 lbs. force) must be used.

Use the following for aerial device operation:- Full body harness (parachute type) and a

shock absorbing lanyard. The lanyardshould have a nominal diameter of at least16 mm (5/8 in.) and be made of nylon orother durable material of equivalent impactstrength and elasticity.

Use the following for tree climbing operations:- Forestry saddle constructed of synthetic web

material, a subpelvic support system andtwo “D” rings.

- Safety rope with a minimum diameter of 12.7mm (1/2 in.) and made of nylon or otherdurable material of equivalent impactstrength and elasticity.

- A pole strap made from rubber impregnatedfabric or nylon fabric with steel snaps att-ached at each end and adjusted by a buckle.A coloured strip often runs through the

38

middle of the belt. When the coloured stripbecomes visible, the strap should bediscarded. Some nylon fabric pole strapsdo not have the coloured strip. These strapsshould be inspected regularly and discardedas soon as visible decay is evident. A polestrap used for work postioning should bepositioned in a manner in which the useprevents the user from falling a distancegreater than .6 m (2 ft.). This strap istypically used as part of a fall restrictsystem in wood pole climbing.

- Arborist lanyards which are easily adjustedfor differing tree diameter and will allow fordouble attachment.

- Pole straps could also be made of syntheticrope with steel snaps spliced in each end.The rope pole straps should have a nominaldiameter of 16 mm (5/8 in.) and be made ofnylon or other durable material of equivalentimpact strength and elasticity. They shouldbe inspected regularly and discarded assoon as visible decay is evident.

- Climbers (spurs) should only be used whenthe tree is to be completely removed and it issafe to climb. There are several differenttypes of climbers available. The kind of barkon the tree will determine which climbersshould be used. For smooth, thin bark trees,climbers with gaffs that are 45 mm (1-5/8 in.)long are suitable. For rough, thick bark, treeclimbers with gaffs that are 70 to 90 mm (2-3/4 to 3-1/2 in.) long are suitable.

39

J. Reflective Vest And Clothing

When a worker is directing traffic, or when aworker could be endangered by vehicular traffic,that worker must wear a vest or clothing that isreflective fluorescent and coloured blaze orangeor red.

2. Tools And Equipment

A. Pruners:- hand pruners- hydraulic pruners

B. Saws:- pruning saw- pole saw- gas powered chainsaw- hydraulic chainsaw- brush saw,- hydraulic pole saw

C. Axes

D. Wedges

E. Felling bars

F. Ladders

G. Ropes

H. Pulleys, locks and lowering devices

I. First Aid Kit

J. Appropriate slings

K. Fire extinguisher

L. Approved fuel container

M. Aerial Devices

N. Chippers

O. Traffic cones and signs

P. Respiratory protection

40

Q. Portable eye wash unit

R. Files/gauges/guides

302 DAILY INSPECTION AND MAINTENANCEOF TOOLS AND EQUIPMENT

Tools and equipment needed to perform line clearingoperations should be inspected daily for any wear,aging, damage or defects. If any problems are noticed,the tools or equipment should be removed fromservice so that they can be repaired or replaced.

1. Rubber GlovesOnly rubber gloves that have received initial accept-ance tests in accordance with CSA specificationsand American Society for Testing and Materials(ASTM) standards shall be used.

All new rubber gloves are marked with colour-coded labels as required by national specifications.The label colour is identified with the listing of thevarious classes and their respective proof testvoltage in Table #3 below.

Table #3

Distance Between Gauntlet and Cuff

ClassDistance "D"

in. mm

00 0.5 13

0 0.5 13

1 1 25

2 2 51

3 3 76

4 4 102

41

Rubber gloves should be:

(a) stored and maintained in serviceable condition

(b) never worn inside out or without leather protec-tors

(c) laboratory retested at least every 90 days

(d) exchanged at any time they become damaged,or whenever the employee to whom they areassigned has reason to doubt their serviceablecondition

(e) air tested and the rubber gloves and leatherprotectors visually inspected immediately priorto each use

(f) rubber gloves should be of an appropriate sizefor the user

The protective covers must match the class ofrubber glove, as there is a required clearancebetween the cover cuff and the rubber glove bead.(See Table #4 and Figure #3.)

Table #4

C lass C olo ur

M ax useVo ltag e

(P hase toP h ase )

R etes tF requ en cy

C lass 00 B eige 500 vo lt 90 days

C lass 0 Red 1 ,000 vo lt 90 days

C lass 1 W hite 7,500 vo lt 90 days

C lass 2 Ye llow 17,000 vo lt 90 days

C lass 3 G reen 26 ,500 vo lt 90 days

C lass 4 O range 36 ,000 vo lt 90 days

42

Gauntlet and Cuff

Maintain the required distance between the covercuff and the glove bead.

The portion of the rubber glove under the cover isthe only part of the rubber glove that is dielectricallytested. The area from the glove bead to the glovecover cuff is visually inspected and air tested only.(See Figure #4, Distance D.)

Rubber gloves should be thoroughly inspectedand air tested at least once each day before useas follows:

(a) Turn gloves inside out and carefully inspect forany cuts, splits or wear spots. Clean gloves areeasier to inspect.

Figure #4

Maintain this

required distance

Recommended safe

working area of glove

Electrically tested area

of gloveD

D

Figure #3

43

(b) Reverse the gloves to the original side out andinspect the surface the same as the insidesurface.

(c) Twirl the gloves to fill with air and trap it byrolling the cuffs. With the free hand, squeezethe gloves in various places and inspect the sur-

face. While the gloves are inflated, hold themup to your face to feel or hear if air is leakingthrough any punctures.

NOTE: Most rubber gloves are manufacturedusing two colours — a black outer sur-face and either a yellow or red insidesurface. The inner surface representsapproximately 80% of the glove thick-ness.

Rubber gloves must not be used when:

- a puncture is located in the glove

- a hard spot or foreign material is located in theglove

- the contrasting inner or outer colour of the gloveis visible through a cut or wear spot from thereverse side

To ensure longer service, rubber gloves should bekept clean and stored in a cool, dark and drylocation without distortion, bending, or undermechanical stress or compression.

IHSA suggests that when rubber gloves are re-turned from the test lab and not immediately put touse, they be kept in the protective plastic bag andstored in the manufacturer’s box on a shelf.

When rubber gloves are not in use, keep them intheir leather protectors in a protective rubber glovebag. Place the fingers down in the bottom of thebag and close the flap to prevent foreign material

44

from getting in.

Inspect rubber glove leather covers thoroughly atleast once each day before use. Look for things likewear in the leather, cuts, chemicals on the leatherand items embedded in the leather that coulddamage rubber gloves.

NOTE: Enemies of rubber are: chemicals, lubri-cating and hydraulic oils, sunlight, ultravio-let light, dampness and heat.

2. Chainsaw

(a) Use the right saw for the job.

(b) Know your saw.

(c) Use all personal protective equipment — head,eye, ear, hand, foot and leg.

(d) Make sure personal protective equipment is ingood condition.

(e) Make sure saw chain is sharp.

(f) Make sure saw chain is properly tensioned.

(g) Make sure chain brake works properly.

(h) Make sure bar is in good condition.

(i) Make sure air filter and air intake screen areclean.

(j) Visually inspect the chain saw for worn ignitionparts, loose nuts, screws, and cracked or wornparts. Correct any faults before use. Rampeddepth gauge is set at .25°.

(k) Clean saw thoroughly — wipe off spilled oil orgas, remove sawdust and debris, especiallyaround cylinders and cooling fins.

(l) Fill oil reservoir and make sure oiler functionsproperly.

45

3. Pole Pruner(a) Suitable, well maintained, non-conductive pole

pruners should be used when working in prox-imity to conductors energized above 750 volts.

(b) Pole pruner ropes should be equipped withinsulated inserts.

(c) Fibre handle pruners at least every 36 months.

(d) Inspect the pole pruner for loose nuts or boltsand cracked or worn parts. Inspect the rope forwear and aging. Correct any faults before use.

(e) Use all personal protective equipment — head,eye, hand and foot.

(f) Wipe down (clean) the pole and insulating linkinsert with a clean cloth. An approved live linetool cleaner (e.g., isopropyl alcohol) can beused on the cloth to help clean the pole andlink. Spot clean stubborn contaminants with adistillate of petroleum (e.g., Varsol). Wash thecleaned area immediately with mild detergentand water; rinse it thoroughly with clean waterand towel it dry.

(g) Keep moving metal parts loose enough toallow free action. Lubricate as required.

(h) Check the coil spring for excessive stretching.

(i) Make sure the blade is sharp.

(j) Examine the pulley and make sure it is workingproperly.

(k) Look for excessive wear on the inside of thehook as it will prevent a clean cut.

(l) When the pole and insulating link are wet andmoist, they should be wiped down before theyare used near energized conductors.

46

(m) Maintain Epoxiglas® poles in the best possiblecondition to ensure their dielectric qualities.

4. Pruning Saw(a) Inspect for loose rivets, cracked or worn parts.(b) Correct any faults before use.

(c) Use all personal protective equipment — head,eye, hand and foot.

(d) Make sure the saw blade is sharp and set.

(e) Wipe down the handle of the saw with a cleancloth. An approved live line tool cleaner (e.g.,isopropyl alcohol) can be used on the cloth tohelp clean the equipment. Spot clean stubborncontaminants with a distillate of petroleum (e.g.,Varsol). Wash the cleaned area immediatelywith a mild detergent and water, then thoroughlyrinse with clean water and towel dry.

5. Brush Saw(a) Know your saw — review the operator’s

manual.

(b) Use all personal protective equipment — head,eye, ear, hand, leg and foot.

(c) Make sure personal protective equipment is ingood condition.

(d) Make sure the blade is sharp and set.

(e) Visually inspect the brush saw for bare ignitionwires, loose nuts, screws and cracked or wornparts. Correct any faults before use.

(f) Inspect and lubricate the throttle linkage.

(g) Lubricate driveshaft bearings.

47

303 WORK AREA PROTECTIONSet out appropriate work area protection (e.g., cones,signs, barricades, etc.) in accordance with the OntarioMinistry of Transportation's Ontario Traffic Manual Book7 Temporary Conditions to ensure a safe workingenvironment is established. This will help preventinjury to workers and the general public.

304 TAILBOARD TALKConduct tailboard talks to ensure all persons on thecrew thoroughly understand the job(s) at hand.

Document the talk and have crew members sign on:

- before any work begins

- when there is any change in the job procedure

- when there are any changes in the personnelperforming the work

305 UTILITY WORK PROTECTION CODEThe supervisor should be completely familiar with theappropriate section of the Utility Work Protection Code(UWPC), so that proper protection for the crew mem-bers can be obtained.

For instance, if the supervisor wanted a section ofelectrical apparatus isolated to create a safer workingenvironment, a work permit could be requested fromthe local power authority. When granted, the supervi-sor will be given guaranteed isolation.

NOTE: The apparatus, when isolated, must bede-energized by the controlling authority.

A situation could also exist where personnel, tools,equipment, trees or limbs may inadvertently cause anoutage. The supervisor should request hold-off protec-tion. Under this protection, the apparatus will notbecome re-energized following an outage.

48

NOTE: Under no circumstances should hold-offprotection be considered apparatus isola-tion. The equipment is still energized underhold-off protection. Remember: the hold-offis used to protect equipment, not people.

49



400 DAILY VEHICLE CHECKS

401 VEHICLE SETUP

402 HOLDING VALVE CHECK

403 SECURING FOR TRAVEL

50



400 DAILY VEHICLE CHECKSCarry out vehicle checks each day as outlined belowand in the operator’s manual. This should be doneprior to vehicle operation.

1. Circle, check and inspect for any unusual condi-tions, such as pools of hydraulic fluid, oil under thechassis, cracked, bent, loose or missing compo-nents or any obvious external damage or impropermaintenance.

2. Check the level of engine oil, radiator coolant andfuel.

3. Check the operation of brake lights, turn signals,four-way flashers, beacon, arrow boards, head-lights, horn and windshield wipers.

4. Check hydraulic oil level in the reservoir with allcylinders retracted.

5. Check the breather cap on the reservoir to makesure it is not clogged.

6. Check that the tires are inflated to proper pressure— use a tire gauge.

7. Adjust the mirrors to give the driver proper rearviewvision.

8. With air brakes - the tank should be drained ofmoisture at least once a day, preferably at the endof a shift, and especially in winter to prevent freez-ing.

9. (a) Check control valves for proper operation.(b) Check holding valves (refer to Section 402).

51

10. (a) Check bucket levelling system for propertension.

(b) Inspect the fibreglass bucket for damage.(c) Check for cracks around welds, hinge pins, and

rod eye bolts.(d) Inspect the cable at anchor brackets, upper,

middle and lower hinge points.(e) Check for flattening or fraying of the cable as it

passes around sheaves.(f) Check for foreign material inside the boom.

NOTE: At no time should hydraulic leaks bechecked by touch. This could result inpressure intoxification.

401 VEHICLE SETUPBefore using a piece of equipment, the operatorshould be familiar with the manufacturer’s operator’smanual. The manual will discuss the limitations of themachine and will point out the proper use of theequipment to stabilize that particular vehicle.

1. Upon arriving at the job site, turn on emergencylighting as required (four-way flashers, rotatingbeacon, etc.).

2. Set out traffic control devices in accordance withlocal by-laws and the MTO publication, OntarioTraffic Manual Book 7 Temporary Conditions.

3. Check the job site to determine the best location forthe truck. Once this has been decided, position thetruck accordingly.

4. Set the parking brake and/or brake lock.

5. Engage the Power Take Off (PTO).

6. Engage spring lockouts, if the truck is so equipped.

7. Position wheel chocks.

52

8. If the unit is so equipped,extend outriggers after placingpads. Be sure outriggers arecentered on outrigger pads formasimum stability. (SeeFigure #5.)

On uneven ground, the padsshould be levelled before theoutriggers are extended.(See Figure #6.) Also, ifthe work location is notlevel, the low sideoutrigger should beextended first to level thetruck, then the high sideextended to obtain a firmcontact with the pad. Iffirm contact cannot bemade, the outrigger pads can be cribbed up untilfirm contact is made.

NOTE: For maximum stability, the total springweight of the vehicle should be restingon the outriggers.

9. Do daily vehicle checks. Refer to the IHSA SafePractice Guide, Hydraulics, and the manufacturer’srecommendations.

10. Ground the vehicle in accordance with the IHSASafe Practice Guide, Temporary Grounding andBonding Techniques.

11. Conduct a tailboard talk.

Figure #6

Figure #5

53

402 HOLDING VALVE CHECKCheck the holding valves on hydraulic equipment daily,prior to use. Use the lower controls.

On electro-hydraulic equipment, check the holdingvalves in accordance with the manufacturer’s recom-mendations.

1. Outrigger Valve Integrity

(a) With the outriggers (whether two or four) ex-tended to remove the total spring weight, shutdown the hydraulic system by one of thesemethods:(i) disengaging the PTO(ii) depressing the clutch(iii) turning off the ignition key(iv) using the by-pass button for main frame or

outriggers

(b) Attempt to retract the outriggers by operatingeach outrigger lever individually. There shouldbe no observable movement.

NOTE 1: Any movement indicates problems.Have the valve overhauled or re-placed. Holding valves for out-riggers are usually nonadjustable.

NOTE 2: In certain types of aerial devices,care should be taken when check-ing an outrigger equipped withshutoff cocks. These shutoff cocksshould be closed or the outriggerscould activate if the controls aremoved, whether the PTO is en-gaged or not. In this case, the out-riggers are usually equipped withholding valves.

54

2. Holding Valves on Aerial DevicesNOTE: Make certain that bucket covers, lan-

yards, chainsaw scabbards and anyother tools are clear before starting theprocedure.

(a) After checking the outrigger valves, reactivatethe hydraulic system.

(b) Put the unit through all of its operations: raisebooms, lower booms, rotate booms and extendand retract the boom, if so equipped. By doingthese operations, any air in the lines will bepurged.

(c) With over centre and fully articulating models,bring the lower boom down to a position tendegrees above its rest, and the upper boom to aposition 180 degrees to the lower boom. (SeeFigure #7.)

(d) Shut down the hydraulic system.

(e) Using the lower controls, operate the upperboom control to unfold the upper boom. Thereshould be no observable movement.

(f) Reactivate the hydraulic system.

Figure #7

180

10

55

(g) With all models, bring the upper and lowerbooms down to a position ten degrees abovetheir rests. (See Figure #8.)

(h) Shut down the hydraulic system.

(i) Operate each control lever individually to lowerbooms. There should be no observablemovement.

NOTE: Any movement indicates problems.Have the valve(s) re-adjusted, overhauled orreplaced by qualified personnel.

3. Holding Valves on Boom Trucks, Cranes andExtensible Boom Platform Trucks

(a) After checking the outrigger valves, reactivatethe hydraulic system.

(b) Put the boom through its operations, then raisethe boom to approximately 60 degrees. (SeeFigure #9.)

(c) Extend the stinger or extension boom half-wayout.

(d) Shut down the hydraulic system.

Figure #8

10

10

56

Figure #9

45 - 60

(e) Operate the levers individually to retract thestinger and lower the boom. There should beno observable movement.

NOTE 1: Any movementindicates prob-lems. Have thevalve(s) re-adjusted, over-hauled or re-placed.

NOTE 2: Some oldermodels do nothave holdingvalves on theextension boom.

403 SECURING FORTRAVEL

1. Return the booms to thestowed position.NOTE: The booms should always be stowed

even if only moving a short distance.

2. Raise the outriggers and ensure they are fullyretracted.

3. Store pads in their proper place.

4. Secure the boom with tie down straps, if required.

5. Disengage spring lockouts as required.

6. Remove wheel chocks.

7. Remove traffic control devices.

8. Disengage the PTO. If this is not done beforebeginning road travel, the pump can be severelydamaged.

9. Turn off all warning lights.

10. Disengage the parking brake and/or brake lock.

57

SECTION V

TREE INSPECTION

500 GENERAL

58

SECTION V

TREE INSPECTION

500 GENERAL

Inspect the tree for hazards before pruning or treeremoval work commences and after the surroundingarea has been secured (e.g., work area protection).

The inspection should include the following:

1. When the integrity of the tree is in doubt, (e.g.,cavities, dying/dead branches, etc.) bore testing forthe internal integrity of the tree should be conductedto ensure the tree is safe to climb.

2. Check for any limbs in contact with conductors.

3. Check for dead wood, hangers or decaying limbs.

4. Examine the tree for the best ascent approach tothe work area.

5. Check for the best branch union to secure thesafety rope.

When removing trees, consider the following:

6. Examine nearby trees which could cause prob-lems.

7. Make sure there is sufficient room for the task.

8. Check the weight distribution of the crown.

9. Check for splits in limbs, crotches and any othertree defects.

NOTE: Binnoculars are recommended whilemaking an assessment from the ground.

59

SECTION VI

TREE PRUNING

600 GENERAL

601 TYPES OF PRUNING

602 PRUNING CLEARANCES

60

SECTION VI

TREE PRUNING

600 GENERALThere are three main reasons for pruning:

1. Line clearance — removal of sufficient tree growthin an approved arboricultural manner, consistentwith good public relations, to provide optimumelectrical service.

2. Sanitation — removal of diseased branches, orwhere branches have been rubbing each other andwhere jagged or broken branches must be re-moved due to storm damage.

3. Aesthetic — pruning to restore the desired form tothe tree.

Proper pruning during line clearing operations willresult in healthier trees and eliminate the followinghazards:

- A limb caught on a line conductor, which couldenergize the tree as well as introduce a partialground to the conductor.

- Fast growing trees under the line may force conduc-tors to contact one another.

- Trees growing too close to power lines will oftenprove hazardous to children who climb them.

- Heavy limbs falling on the line could cause poweroutages.

As in all work methods, a standard must be set not onlyto protect the tree, but also to eliminate hazards toworkers and the general public. Those standardsshould include the following:

61

- To protect the bark, use climbers for removals only.

- Carry out corrective pruning (remove stubs, deadbranches, etc.) to eliminate existing hazards.

- Remove weak and diseased limbs.

Maintain safe and proper pruning by using an insu-lated pole pruner and a pruner saw. Pruning tools arecovered in Section III.

601 TYPES OF PRUNINGThere are three basic types of pruning in line clearingoperations: crown, side and under. Which type you usedepends on tree species, position of conductor inrelation to the tree, line voltage and cycle clearancerequirements.

Crown Pruning (Crown Reduction)This is considered the most difficult to perform be-cause of the awkward working position (working in thebody of the tree) and the need to visualize the endresult.

Reasons for Crown Pruning:

- to control trees growing under the conductors;

- to control trees growing beside the line and closeenough to dead wood and broken branches topose a problem; and

- to control large and small trees weakened by stormdamage or shallow root systems.

Whenever possible, preserve the natural shape of thetree. Avoid the “V”, “L”, “U”, or flat top shapes.

NOTE: Removing more than 30% of crown growthcould result in stress related problems andearly mortality of trees.

62

Table #5 gives a sample selection of different speciesand their growth rates. Consult tables like thesebefore establishing a pruning cycle or before workingon a species with which you are unfamiliar.

Table #5

Tree Species and Rates of Growth

Very Fast Fast Med ium Slow

Carolina Poplar Willow Tulip Sugar Maple

Cottonwood Locust Black Cherry Horse

Lombardy Manitoba Maple Aspen Chestnut

Red Pine Hickory

Elm White Oak

Red Maple Beech

White Pine Balsam Fir

Sycamore White Spruce

Scotch Pine Black Spruce

Birch Hemlock

Jack Pine White Cedar

Red Oak

Basswood

Walnut

Ash

Larch

Norway Spruce

602 PRUNING CLEARANCESIn order to maintain a pruning standard, maintainpruning clearances and establish a pruning cycle.

63

Table #6

CLEARANCES (in metres)

2 YRS 3YRS 2 YRS 3 YRS 4 YRS 3 YRS

Top Side Top Side Top Side O.H. Top Side O.H. Top Side O.H. Side

EX. FAST 2 1.7 3 2 2 1.3 1.7 3 1.7 2 3.6 2 2.7 1

FAST 2 1.7 2.7 2 1.7 1.3 1.7 2 1.7 2 3 2 2 1

MED 1.7 1.3 2 1.7 1.3 1 1.3 2 1 1.7 2 1.3 2 .7

SLOW 1.3 1.3 1.7 1.7 1 1 1 1.3 1 1.3 1.7 1.3 1.7 .7

Table #7

CLEARANCES (in feet)

2 YRS 3YRS 2 YRS 3 YRS 4 YRS 3 YRS

Top Side Top Side Top Side O.H. Top Side O.H. Top Side O.H. Side

EX. FAST 7 5 9 6 6 4 5 9 5 7 11 6 8 3

FAST 6 5 8 6 5 4 5 7 5 6 9 6 7 3

MED 5 4 6 5 4 3 4 6 3 5 7 4 6 2

SLOW 4 4 5 5 3 3 3 4 3 4 5 4 5 2

Tables #6 and #7 contain allowance for sag, but in themiddle of winter, an extra 0.30 - 0.60 m (1-2 ft.) ofclearance should be obtained on spans up to 91 m(300 ft.) long and an extra 0.60 - 1.3 m (2-4 ft.) onspans over 91 m (300 ft.) long on trees at centre span.

You may set a more stringent pruning cycle, dependingon species within your area. However, the followingshould be regarded as the maximum length of time

SUBTRANSMISSIONVOLTAGE LINES22,000-44,000 V

DISTRIBUTION LINES

2,300-15,000 V

SERVICE LINES115-230 V120-240 V

SUBTRANSMISSIONVOLTAGE LINES22,000-44,000 V

DISTRIBUTION LINES

2,300-15,000 V

SERVICE LINES115-230 V120-240 V

64

between cycles to maintain a consistent standard:

- On voltages 2.4 kV to 27.6 kV: six to eight years

- On voltages 27.6 kV to 44 kV: four years

NOTE: These tables are guidelines and environmen-tal conditions or poor pruning habits mayaccelerate growth rates in most species oftrees. Opening up the the crowns of trees toomuch may lead to premature structuralfailure.

65

SECTION VIl

TREE CLIMBING TECHNIQUES

700 GENERAL

701 CROTCH/BRANCH UNION SELECTION

702 FRICTION HITCH AND TERMINATIONKNOT SELECTION

703 ASCENDING ROPE ASSISTED ON ACONVENTIONAL (CLOSED) CLIMBINGSYSTEM

704 ASCENDING WITH CLIMBERS (SPURS)

705 FORMULA FOR THE FORCES CREATED

706 CLIMBING USING A PORTABLE LADDER

707 MANOEUVERING IN THE TREE

708 POSITIONING/TYING IN

709 DOUBLE POSITIONING

710 DESCENDING THE TREE

711 REPOSITIONING

66

SECTION VII

TREE CLIMBING TECHNIQUES

700 GENERAL

Before climbing the tree, visibly inspect the path ofascent and decide where the tying in will take place.The inspection should include the following:

- conductor location

- possible electrical hazards (branch contacts)

- location for final tying in

The tying in process will be the tree worker’s choice,regardless of the method used to climb.

701 CROTCH/BRANCH UNION SELECTIONThe selection of suitable crotches is the ultimateresponsibility of the climber, who must rely on trainingand experience to identify all possible hazards. Thiswould include:

- identifying the tree species and its related character-istics (e.g., the brittleness of white pine, poplar,willow, etc.)

- ambient temperature (e.g., winter versus summer)

- the main stem and the support branch must besound and the joint size capable of supporting theclimber’s weight, 10:1 safety ratio should becondidered

- the crotch should be open to allow free running ofthe rope

- wherever possible, locate the crotch so that if a slipoccurs the climber cannot swing into any conduc-tors

67

- a secondary point of attachment should be main-tained at all times (eg; lanyard, double crotch, etc.)

- the crotch height above the work location

- the crotch accessibility

See Figures #10 and 11 for examples of fail safe(retractable lanyard) and Figure #12 (double unionattachment) or redundant systems.

Figure #10

Figure #11

68

Figure #12Example of Fail Safe Climbing

(double union attachment)

Figure #13

Best Practice Less Stable

Once a suitable crotch has been selected, pass thesafety rope through the crotch. Ensure the climbingline encompasses the main trunk (bole). (See Figure#13.)

69

The tree worker has several methods of completingthis task safely:

- using the pruner head and sections of the prunerhandle

- using a throwing ball or “monkey’s fist” with at-tached light nylon line

- using a roping tool designed to catapult a linethrough the tree crotch (rarely used)

When the rope has finally been placed through thecrotch, it can be attached to the climber, who may thenstart to climb the tree. Fall protection is mandatoryonce a worker is 3 m (10 ft.) above ground level. Bestpractice suggests climbers be secured from groundlevel.

702 FRICTION HITCH AND TERMINATION KNOTSELECTION

As of February 1, 2006 a report was generated by theArborist Industry Committee which has attempted tostandardize acceptable friction hitches and terminationknots.

Acceptable industry-tested friction hitches are:

Figure #14

Taut Line Hitch(closed system)

70

Figure #15Blake's Hitch

(closed system)

Figure #16Prusik Hitch

(6 coil, double static line)

Gripping Hitch(closed system)

Figure #17

71

Klemheist(double static line)

Figure #18

Swabish(10 mm Tenex)

Figure #19

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Acceptable industry tested termination knots are:

Figure #20Becket's Bend

(80% of tensile strength)Figure #21

Anchor Bend

(73% of tensile strength)

Figure #22

Bowline


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Figure #23

Figure eight on a bight


Figure #24

Girth Hitch off spliced eye


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Figure #25

Double Fisherman's Knot

Figure #26Triple Fisherman's Knot

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703 ASCENDING ROPE ASSISTED ON A CONVEN-TIONAL (CLOSED) CLIMBING SYSTEM

1. The body thrust, used in conjunction with a frictionhitch, is a safe method of climbing since theclimber is tied in with a friction hitch prior to leavingthe ground. For best results, position the ropeclose to the tree trunk.

NOTE: A second point of attachment should bemaintained at all times while climbing.

(a) With the rope properly crotched, snap thelocking captive eye karabiner to the saddle.

(b) Using a 1-2 m (3-6 ft.) tail from the lockingcaptive eye karabiner, tie a figure eight hitch anda friction hitch around the other end of the rope.

(c) Tie a figure eight knot in the tail after the frictionhitch, to prevent it from rolling out.

(d) Slide the friction knot as far up as possible with-out leaving the ground. Position the feet on thetrunk of the tree.

(e) Place both hands below the friction knot with thestronger arm, or holding arm, below the handthat will slide the knot.

(f) Walk up the tree to about waist height. Leanback to an almost horizontal position. (SeeFigure #27.)

(g) Simultaneously, brace the feet on the treetrunk, bend the knees, pull down on the runningend of the rope which brings the friction knotclose to the chest, and thrust upward with thehips. If done correctly, all of the body weight isnot being pulled by the arms. This is arhythmic technique.

(h) With the strong arm in a locked position, and thehand gripped to keep the running end from

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sliding back down, slide the top hand up therunning end beneath the friction hitch. Thefriction hitch should move with the top hand.

(i) Once a rhythm is established, continue to thefirst limb.

2. The body thrust on belay is similar to the bodythrust using a friction hitch. However, a person onthe ground is used to prevent the climber fromfalling on a secondary rope.

NOTE: A second point of attachment should bemaintained at all times while climbing.

(a) With the rope properly crotched, the climberattaches the safety hook to the saddle. A Münterhitch is tied into a karabiner. Whether thekarabiner is attached to the tree using a rope(See Figure #28), or to the "D" rings of thesaddle worn by the person on the ground (SeeFigure #29), is dependent upon the difference inweight between the climber and the otherperson. If the climber is more than 11 kg (25lbs.) heavier, the tree method must be used.

Figure #27

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Figure #28

Figure #29

78

Figure #30

(b) Once this has been established, the climberuses body thrusts to ascend the tree, while theperson on the ground takes up the slack on therope. When the climber has reached the worklocation, or a point in the tree where it is neces-sary to recrotch the climbing rope, a lanyard isused to secure the climber in the tree.

(c) Before proceeding with the repositioning of therope, the climber should shout down to theperson on the ground doing the belaying "OFFBELAY". The belayer will undo the rope fromthe karabiner, allowing the climber to repositionthe rope.

(d) Once the climber has connected the lockingcaptive eye karabiner of the rope to the saddle,the belayer ties another Münter Hitch to thekarabiner. The belayer then shouts up to theclimber "ON BELAY". This signals the climberit is safe to disconnect the lanyard and continueto the work location. This procedure is repeatedas often as neces-sary until the finaltie in position hasbeen reached.

Figure #30 illus-trates how to form aMünter hitch.NOTE: There aremany mechanicalbelay deviceson the markettoday which takethe place of theMünter hitch.

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3. The Secured Foot Lock is another metho ofaccessing the work area. Figure #31 shows theprocedure for footlocking.

NOTE: A redundant fall protection is requiredwith this technique and is to be used byadvanced climbers.

When ascending to the work location, a prusik loopis used to secure the climber to the rope. (SeeFigure #32.)

Prusik loops come pre-made with serial numbersnad manufactured dates in order to accomodateyour firms' fall protection program.

Figure #31

Figure #32

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Figure #33

F = W x L D

F = Force perpendicular tothe tree at the crotch

W = Climber's weightL = Horizontal length from

the saddle to the treeD = Distance from where the

rope is crotched to theclimber's feet

704 ASCENDING WITH CLIMBERS (SPURS)

Use climbers only on trees that are to be removed.

Before starting to climb, visually inspect the tree forloose bark, cracks, decay spots, knots and stubs.

Pole climbers may be used in thin barked trees wherethe gaff will penetrate into the wood.

Tree climbers must be worn if the bark is deeplyfissured or thick. The gaff may not hold a person’sweight unless it penetrates into solid wood.

Once the climb has been completed and the worker issecure (using the tree worker’s friction knot), the workmay begin. However, to use the rope most effectively,remain well under the crotchcontaining the rope. Underno circumstances shouldthe worker crotch in theimmediate work zone.

705 FORMULA FOR THEFORCES CREATED

The following formula isdesigned to show the forceexerted where the rope iscrotched only. It is notintended to address all thevariables associated withspecies, season, tempera-ture, etc. Each componentof the formula is illustratedin Figure #33.

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Forces perpendicular to the tree at the crotch =

(Climber’s weight) x (Horizontal length from the saddle to the tree)

(Distance from where the rope is crotched to the climber’s feet)

Therefore, to decrease the force perpendicular to thestem at the crotch, it is necessary to do one or all of thefollowing:

(a) decrease the climber’s weight (W)

(b) decrease the horizontal length (L) from the body tothe tree (or reduce the angle the rope makes withthe tree)

(c) increase the distance (D) from where the rope iscrotched to the climber’s feet

Using a climber’s weight and the formula, you can see,as the distance changes, the perpendicular forcesalso change. Table #8 shows the results using aclimber weighing 90 kg (200 lbs.).

Table #8

W D L Force

Perpendicular

kg lbs. m ft. m ft. kg lbs.

90 200 0.6 2 0.9 3 136.0 300

90 200 0.7 2.5 0.9 2.95 107.3 236.6

90 200 0.9 3.0 0.8 2.82 85.5 188.5

90 200 1.0 3.5 0.7 2.59 67.3 148.4

90 200 1.2 4.0 0.6 2.23 50.7 111.8

90 200 1.3 4.5 0.5 1.65 33.4 73.7

90 200 1.4 4.9 0.2 0.76 14.2 31.3

Table #8 shows that, as the distance between thecrotch-in point and the climber’s feet increases, theforce perpendicular at the crotch is reduced.

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706 CLIMBING USING A PORTABLE LADDER

Use of Portable LaddersUse only approved, nonconductive ladders in forestrywork. Fibreglass ladders must conform to the appro-priate CSA standard.

1. When working aloft from a portable ladder, neverplace the ladder on a truck or other movable object.

2. When working aloft from a portable ladder, it shouldbe secured at the top and bottom to avoid apendular swing.

3. Ladders should be removed from trees when not inuse and while heavy branches are being lowered.

4. Don’t use sectional ladders consisting of morethan three sections.NOTE: When a ladder is erected for climbing,

place it so that the horizontal distancefrom the base to the vertical plane ofsupport is approximately one quarter ofthe ladder length between supports.This is known as the 4:1 rule.

If, through necessity, the base distance exceeds the4:1 distance, block the ladder footing or have it heldby another worker to prevent slipping. If the basedistance is less than required, hold the ladder untilthe top is tied to prevent it from falling backward.(See Figure #34.)

5. Clean mud, snow, or any other substance from yourboots before climbing a ladder.

6. Always face the ladder, whether climbing up ordown. Place hands on the centre of the rung andalternate one above the other as you climb. Maintain a firm grip.

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7. Never climb aladder wearingclimbers. Whenworking from aladder, use atree body belt andsafety lanyard forsupport. Whenpassed aroundthe ladder, thisallows the use ofboth hands towork and, at thesame time, helpsmaintain balance.

8. Don’t stand onthe top threerungs.

9. If the ladder is notlong enough for the job, don’t use it.

10. Don't overreach from any position. Move the ladder.

11. Two workers are not allowed on the same ladder atthe same time.

Remember These Safe Practices When WorkingWith Ladders:

- Check the ladder for defects before using it

- Make sure it is the proper length

- Set it on firm, level ground

- Remember the 4:1 rule

- Maintain a three-point contact while climbing andalways face the ladder

- Maintain a firm grip

- Tie off whenever possible

Figure #34

(4 : 1)

B

A

A to B(4 : 1)

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NOTE: See the IHSA Safe Practice Guide,Ladder Safety for more information onladders.

707 MANOEUVERING IN THE TREEThe ability to move freely about in trees with confidencecan only be achieved through experience. The naturalability to balance, aided by the proper use of the safetyrope, allows the worker to be located in the mostconvenient position. This permits the climber to workwith both hands, clearly see the work to be performedand observe any hazards that may be present. Theproper use of the safety rope is the key to easy move-ment.

The following will help the climber to perform the workmore safely and efficiently:

- There should be no slack in the safety rope be-tween the tie-in point and the climber.

- For most jobs, a safety rope and saddle are notintended as a seat. Lean against the rope so itsupports a portion of the body weight while the legssupply balance. This allows movement on limbsthat may not otherwise support the climber’s fullweight.

- The best position for pruning in a tree is to be justbelow the work area and looking up and out.

- When working above conductors, considerationshould be given to the location of the free end of therope, as well as any small tools, in order to avoidconductor contact. Always maintain the safe limitsof approach as outlined in the Electrical UtilitySafety Rules (EUSR).

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708 POSITIONING/TYING INTo properly position a safety rope in a crotch and tie inwhile protected from falling (e.g., lanyard):

- Pass the safety rope through the selected crotchand around the main stem that is to support theclimber’s weight.

- Fasten the locking captive eye karabiner to thesaddle “D” rings by passing it through both “D”rings and securing the keeper.

- Tie the friction knot to the running end of theclimbing line.

- Test the friction knot before trusting full weight to it.

NOTE: The acceptable size of a forester’s climb-ing line is 12.7 mm (1/2 in.) nylon or otherdurable material of equivalent impactstrength and elasticity.

709 DOUBLE POSITIONINGIt is sometimes impossible for the safety rope,crotched in the original position, to supply the neces-sary support and balance needed at all locations. Onemethod of obtaining the required support is to tempo-rarily crotch a second time, at the new location. This isknown as “double positioning”. This technique willensure a redundancy at all times while climbing.

To double position, select a location either through acrotch or around a limb that will provide the desiredsupport. Using the terminal end of the running portionof line, pass it over the new crotch or limb and tie it tothe saddle “D” rings using a secure knot (ie; anchorbend, Becket's bend, etc).

Tie the securing knot approximately 1 m (3 ft.) from therope end. Tie the rope end to the new running end

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using an acceptable friction hitch. By adjusting the twofriction hitches, the forester will be held in the desiredposition. (See Figure #35.)

A forester’s body belt is equipped with "D" rings,therefore, it may be more convenient to make use ofthe adjustable lanyard instead of double positioning.

710 DESCENDING THE TREETo descend the tree:

- Be sure the running end is free from any obstruc-tions, such as severed branches, knots, etc. and itfollows a clear path to the ground.

- Should a slip occur, be sure the forester will notswing into any conductors.

- Be sure the running end has a figure eight knot tiedto the end and is long enough to allow the climberto reach the ground.

NOTE: Once tied into the tree, remain tied in atall times until you are back on theground. Do not untie the friction hitch to

Figure #35

Becket

Friction

Friction

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descend, except when repositioning andalways secure a lanyard as a secondattachment point.

711 REPOSITIONINGOccasionally, when working in exceptionally high trees,the climber will find that the fall line is not long enoughto completely descend. To overcome this problem, itwill be necessary to reposition. The procedure for re-positioning is similar to double positioning.

1. Descend to a point where, after repositioning,sufficient fall line will be available to allow you toreach the ground.

2. Select a suitable branch union.

3. Retrieve the end of the running line and pass itthrough the new union. Then, using a terminationknot, tie it to the safety saddle “D” rings. Tie thetermination knot approximately 1 m (3 ft.) from therope end.

4. Using the 1 m (3 ft.) rope end, now tied to the “D”rings, tie a friction hitch to the rope that will becomethe new running end.

5. Untie the original friction hitch, then untie thelocking captive eye karabiner.

6. Pull the running end from the original crotch andlower it to the ground ensuring a figure eightstopper knot is secured to the distil end of therunning portion of rope.

7. Continue descending to the ground.

A forester’s body belt is equipped with side “D” rings.Therefore, it may be more convenient to make use ofthe adjustable lanyard or pole strap when reposition-ing. It is permissible to do this providing the lanyard or

88

belt is properly attached to the side “D” rings andaround a main stem of suitable size to support theclimber’s weight. This must be completed before anyalterations are made to the original tie-in configuration(e.g., untying the friction hitch).

NOTE: Where practical, line clearing operationsshould be performed from the bucket of anapproved insulated aerial device.

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SECTION VIII

WORKING NEAR ENERGIZED CONDUCTORSAND APPARATUS

800 GENERAL

801 WORKING ABOVE THE LEVEL OFENERGIZED CONDUCTORS

802 LIMB REMOVAL IN PROXIMITY TOENERGIZED CONDUCTORS

803 REMOVING LIMBS FROM CONDUCTORCONTACT

90

SECTION VIll

WORKING NEAR ENERGIZED CONDUCTORSAND APPARATUS

800 GENERALAn area of concern to the forester is work near ener-gized equipment. The following should help provideknowledge to create a safe work environment:

1. Wood, whether dry, green or wet, should bedeemed at all times to be a conductor of electricity.

2. When working above conductors, an approvedinsulated aerial device should be employed.

4. Maintain personal safe limits of approach at alltimes.

3. Should a limb be found to be in actual contact withan energized conductor, or so close to a conductorthat it is likely to be brought into contact either by aslight gust of wind or by movements of the limb,contact the controlling authority for appropriate workprotection.

4. When pruning near energized conductors orapparatus, use a pole pruner which has beendielectrically tested. Cut in an insulated link insertto the pruner rope at a designated position. (SeeFigure #36.)

5. Face the conductors whenever possible. Removefoliage obstructing your view.

6. Pruner cuts are safely made up to a diameter of 2.5cm (1 in.). Use a saw to make larger cuts.

7. Be constantly aware of the conductor position whilepruning above and beside energized lines andmaintain the safe limits of approach at all times asoutlined in the EUSR.

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8. The insulating link cut into the pruner rope mustnever be bridged by any portion of the body orapparatus when within contact distance to ener-gized equipment.

9. If a conductor of a power circuit is broken by anycircumstance, consider the broken conductor aliveand do not touch it untiI protection is established inaccordance with the Utility Work Protection Code(UWPC). Report its location at once to the appro-priate operating or utility authority. The personreporting the hazard should be governed by theinstructions received.

10. Weatherproof covering on conductors is notconsidered insulation. Consider covered conduc-

Pulley

Rope

Snap

215 mm(8.5 in.)

InsulatedLink

Figure #36

Pole

215 mm(8.5 in.)

Head

Lever

SpringHook

Blade

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Figure #37

Conductor spacing

Length of piece of limb

Limb must beshort enough tofall between con-ductors. Limbs thisshort cannot hit twoconductors at the sametime.

tors bare and alive unless it is positively known thatthey are isolated and de-energized.

801 WORKING ABOVE THE LEVEL OFENERGIZED CONDUCTORS

1. Carefully remove branches that are likely to breakand fall on the conductors and any branches whichare likely to whip into the circuit during the clearingoperations.

2. Large branches which are to be cut directly above aline should be controlled and lowered by means ofappropriate rope and rigging techniques.Branches which are to be pruned or removed fromabove a line and which are too small to requireroping, should be cut off in short lengths, eachlength to be shorter than the distance betweenpower line conductors. (See Figure #37.)

Use approved pruners and do not touch by handany branch which is in position to contact a liveconductor.

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802 LIMB REMOVAL IN PROXIMITY TOENERGIZED CONDUCTORS

The removal of limbs can be a hazardous job. Thefollowing proper safety precautions should be ob-served:

1. The worker should keep in mind the location of:

(a) live conductors(b) private property, (e.g., fences, houses, flower

beds, vehicles, etc.)(c) equipment (e.g., trucks, chipper, guy wires, etc.)(d) co-workers, whether aloft or on the ground

2. Do not let limbs swing in such a manner that theycould cause contact with energized conductorsand/or co-workers.

Method

1. Attach a lowering rope to the limb to be lowered outbeyond the balance point.

2. Crotch the rope in at the main trunk above the limbto be lowered.

3. The worker on the ground should not exert pres-sure to raise the limb.

4. The worker begins the undercut.

5. The worker on the ground applies pressure to thelowering rope to:(a) relieve the bind on the worker’s saw, and(b) pull the limb up to where the rope is crotched.

6. When the limb is pulled up to as nearly vertical aspossible, the worker completes the cut.

7. On completion of the cut, the limb is lowered safelyto the ground.NOTE: Guide ropes may have to be attached to

gain better control of the limb beinglowered. When large limbs are encoun-

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tered, additional rigging may be re-quired to employ mechanical advantageand control.

803 REMOVING LIMBS FROM CONDUCTORCONTACT

1. If a limb falls and becomes lodged on one or moreconductors, warn workers to stay clear in the eventthe conductor burns off and falls to the ground andcontact the controlling authority.

2. Use insulated pole pruners and rubber gloveswhen removing limbs in close proximity to ener-gized conductors from the bucket of an approvedinsulated aerial device.

3. In the event the limb is too large for the pruners or ahazardous situation exists, the crew should contactthe controlling authority in order to obtain isolationand de-energization before starting to work.

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SECTION IX

TREE REMOVAL

900 SAFE PRACTICES FOR TREE REMOVAL

96

SECTION IXTREE REMOVAL

900 SAFE PRACTICES FOR TREE REMOVAL

1. All mature oak, beech and basswood, and all over-mature trees of doubtful strength should (if neces-sary) be diagnosed with a brace and bit. All treesmust be visually inspected before felling.

2. All trees that would strike a power line in falling, orcause damage to property, must be properly roped,guyed and anchored. Do not use pike poles.

3. Respect the hazards and danger presented by drystumps, chicots (“widow makers”), or dead trees.

4. Fell trees directly away from power lines andassociated equipment. When this is not possible,top trees sufficiently to provide adequate clearance.

5. The felling area must be at least equal in radius tothe height of the tree. The danger zone includesthe felling area plus an additional area designatedby the supervisor.

6. The saw operator(s) must have a clear and ad-equate escape route at an angle of approximately45 degrees to the rear of the notch, never directlyaway from the direction of fall, in case the treeshould kick backward off the stump. Always movein an uphill direction when felling trees along aslope. (See Figure #38.)

7. No one except the operator is allowed within 1.8 m(6 ft.) of a power chainsaw in operation.

8. Make all felling cuts properly and leave a minimumof 2.5 cm (1 in.) holding wood uncut to hinge thetree.

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9. Abandon the saw if it hampers your escape.

10. The saw operator(s) must be clear of the areadirectly beneath the tree before it is pulled over.

11. Saw operators must be constantly alert for fallingdeadwood when felling trees.

12. Wear approved protective clothing: eye, ear, head,hand, foot and leg protection when operating chain-saws.

NOTE: Protective leggings are not requiredwhen working from the bucket of anaerial device.

13. Never turn your back on a falling tree. Although youare watching your path of movement away from thestump, do not lose sight of the falling tree.

14. When the tree strikes the ground, the butt portionmay move a considerable distance, depending ontrees, terrain, etc. Be aware of the danger presentto workers by such movement. Ensure the tree hascompletely settled before moving in to removerigging or commence bucking operations.

Tree height

Sawoperator'sescape route

Anchor

Pullrope

LEGEND- Tree to be felled- Felled path- Felling area- Danger zone

Figure #38

98

15. Take extra care while wearing snowshoes duringfelling operations.

16. Maintain good communication between the sawoperator(s) and other members of the crew.

17. When felling trees, you may attach a guide rope to astationary vehicle, provided the vehicle is renderedinoperative and of appropriate weight for tree beingfelled.

18. Don’t leave a partially cut tree standing when workhas been suspended.

19. lf a tree becomes lodged on energized electricalapparatus and cannot be removed by approvedwork procedures, notify the power authority so thatisolation and de-energization can be establishedbefore removal begins.

20. The climber’s climbing rope must never be usedas a pulling or guide rope. Use appropriatediameter and strength of rope for the task at hand.

21. Employ felling wedges and felling bars whereapplicable.

22. Only competent employees should attempt fellingprocedures or employees under the direct supervi-sion of a competent person.

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SECTION X

SAFE LIMITS OF APPROACH

1000 GENERAL

100

SECTION X

SAFE LIMITS OF APPROACH

1000 GENERALWhen working near energized apparatus and equip-ment there are certain limits on how close workers maycome to that equipment. These limits are called the“Safe Limits of Approach” and are really warningbarriers. They indicate that movement any closer willplace the worker(s) in a danger zone.

The following information should help the worker(s) toremain outside that danger zone:

1 . Ontario Regulations for Construction Projects statethat worker(s) shall not bring any object, includingthe worker(s) closer than 3 m (10 ft.) to a power linefor electricity rated at more than 750 volts.

2. When work is:(a) being performed in accordance with the rules,

techniques and procedures approved by E&USAfor work in close proximity to energized powerlines and equipment

(b) being performed by persons who are qualifiedto do such work

(c) being performed using tools, clothing andequipment specifically designed for such work

(d) being supervised by a competent person; thenTable #9 - Safe Limits of Approach (AuthorizedPerson) — may be used.

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Table #9

Safe Limits of Approach (Authorized Person)

Voltage Range Minimum

(Phase to Phase) Clearance

750 to 35,000 0.9 m (3 ft.)

> 35,000 to 50,000 1.2 m (4 ft.)

> 50,000 to 150,000 1.5 m (5 ft.)

> 150,000 to 250,000 2.1 m (7 ft.)

> 250,000 to 550,000 3.7 m (12 ft.)

• Only authorized workers or workers under thecontinuous direction of an authorized worker mayapproach, work, or allow material or conductivetools to approach exposed energized electricalapparatus to limits as stated.

• In planning the task to be performed, considerationmust be given to the worker’s position in relation tothe exposed energized apparatus such thatplanned movements of the worker’s body orconductive tools, material or vegetation will notresult in any encroachment upon these limits.

3. When either the supervisor, or any worker(s)working near energized conductors or apparatus isnot sure of the voltage levels, contact the localpower authority before anyone goes aloft.

4. Any aerial device used to raise a worker(s) inproximity to energized apparatus or equipmentshall be equipped with upper and lower controls.The lower controls shall be capable of positivelyover-riding the upper controls.

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5. Good judgement should be used at all times andremember:Approved rubber gloves with a minimum Class 2rating (20,000 volts) with leather protectors shall beworn when a worker(s) is working within, or thatwhich is being worked on (branches, limbs) iswithin 3 m (10 ft.) of apparatus energized between0 and 50,000 volts phase to phase.

103

SECTION XI

SAFE CLEAN UP PROCEDURES

1100 SAFE PROCEDURES FOR USE OFBRUSH CHIPPERS

1101 STUMP REMOVAL

1102 HAULING OF BRUSH

1103 WORK ON CUSTOMER PREMISES

1104 TOOL CLEAN UP

104

SECTION XI

SAFE CLEAN UP PROCEDURES

1100 SAFE PROCEDURES FOR USE OF BRUSHCHIPPERS

Safe Practices

1. Make sure all workers are trained in the mainte-nance and safe use of brush chippers.

2. Maintain mechanical brush chippers in accordancewith standard practices and manufacturer's specifi-cations.

3. Workers chipping brush, and those working closeto the chipper, shall wear approved face, eye, ear,hand, head and foot protection.

4. Use work area protection (refer to Section 303,Work Area Protection).

5. Do not start the chipper until it has been inspectedto ensure that the chipper blades are free fromobstructions.

6. When starting portable and hydraulic chippers,bring them up to recommended RPM gradually andreduce their speed slowly to stop.

7. Check the feeder chute for foreign objects beforestarting the chipper.

8. Use all guards and protective devices installed onthe chipper by the manufacturer.

9. Shut down the engine immediately if any irregularityoccurs and do not restart it until the condition hasbeen remedied.

10. Check for and remove any wire, stones or othernon-wood debris embedded in the brush.

105

11. When feeding brush into the chipper, stand off toeither side of the feed table, not directly behind it.Standing on the curbside is best practice in order toavoid vehicular traffic.

12. Feed only the amount of brush that the chipper canreadily accept. The amount and diameter of thebrush should be governed by the capacity of eachunit.

13. Do not try to force brush into the unit. The chippershould feed itself after the brush has come intocontact with the revolving blades. If it doesn’t, theblades and/or cutting bar are probably dull or theblade is not set properly.

14. Workers should approach a chipper in single file.After feeding brush into the chipper, they shouldturn away from the travelled portion of the road asthey leave.

15. Keep the chipper as far to the side of the road asyou can when chipping brush on a travelled road-way.

16. Do not chip brush close to pruning or fellingoperations. The noise might interfere with spokeninstructions.

17. Wear loose fitting gloves while feeding brush into achipper and stand to one side of the feeder chute toprevent injury due to kickback.

18. If a traffic vest is required, make sure it is of the tearaway type.

19. Do not use your hands or feet to push brush pastthe face of the feeder chute. Use a push stick orbrush to force shorter or thorny brush into thechipper. Be careful to avoid kickback when chip-ping dead wood.

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20. Do not stand or pass directly in front of the exhaustchute while the brush chipper is running.

21. Do not stand or sit on any part of the brush chipperwhile it is operating, or while it is being moved fromone job site to another.

22. Ensure that brush is sectionaed into appropriatelengths and free of bends. This should ensurebrush runs straight off feed table and avoidsinadvertant movement toward operators.

23. Chips, if possible, should be unloaded from thetruck the same day as the chipping is done. Woodchips that have been left for more than two dayshave been known to cause nausea and headachesfor workers unloading them. If chips are left in thedump box for extended periods, the worker shouldwear a respirator while working in the encloseddump box.

24. Never leave a chipper unattended while it is inoperation.

25. Turn the motor ignition switch to the “OFF” positionand remove the key before servicing any brushchipper.

26. Lock and block drums to prevent rotation beforemaintenance procedures. Leave the blocks in placeand tag the chipper until the maintenance is com-plete.

27. Wear hand protection while working on or near thechipper blades.

28. Sharp edges of used and new blades should becovered with a designed guard or masking tapewhile maintenance is being performed.

29. When changing the blades on any make of chipper,make sure that the bolts and the bolt holes in the

107

wedges and cylinders are in good condition, andthat they are completely free of dirt or any otherforeign matter.

30. After changing the blades on any make of chipper,check to make sure that the wedge locking boltsare securely tightened. Follow this sequence tocheck the wedge locking bolts between bladechanges:

FOR THE FIRST TWO DAYS AFTER CHANGING

THE BLADES: Check the wedge locking bolts fortightness, at the job site before starting the chipperand again after chipping brush for the first fiveminutes.

FOR THE FIRST TWO DAYS AND UNTIL THENEXT BLADE CHANGE: Check the wedge bolts fortightness, at the job site once a week before startingthe chipper.

PermissionIf you can get permission from the Ministry of theEnvironment, proper road authorities or adjacentproperty owners, it may be acceptable to blow woodchips along the roadside. Depending on the circum-stances, the wood chips may have to be loaded onto atruck and disposed of in another approved location.

Public Relations1. Move the chipper frequently along the proposed

chipping area to eliminate unsightly piles of chips.Spread the chips manually if this is not practical.

2. Do not chip brush onto driveways, lawns, flowerbeds, hedges, or any other area where it mightannoy the public.

3. Do not blow chips across the road.

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4. Remove chips from culverts, drains and ditches sothey do not interfere with drainage.

Coupling and Uncoupling Trailer Mounted Chippers1. Use enough workers to safely handle and control

the weight of the chipper whenever coupling oruncoupling a trailer mounted chipper.

2. Only one person should give signals to the truckdriver when attaching the chipper.

3. For proper control, do not push the chipper by handto the vehicle — back the vehicle to the chipper.

4. Check the trailer hitch to make sure the lockingmechanism is working properly before attachingthe chipper to a vehicle.

5. Install approved chains and connectors betweenthe vehicle and the chipper trailer. If there is afailure, the chains will prevent the chipper fromdetaching. Cross the safety chains beneath thetrailer tongue, allowing only enough slack to permitturning.

6. When coupling or uncoupling, the trailer must beproperly blocked to ensure balance and immobility.

7. Do not walk between a vehicle and its connectedtrailer while they are in motion, or likely to bemoved.

8. Before moving the chipper, attach the brake andlight cables and check the trailer’s brakes andlights for proper operation.

1101 STUMP REMOVAL

Mechanical Removal1. Ensure that loose material around the area of the

stump is removed prior to operation (e.g., rocks,snow, ice, etc.).

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2. Ensure that the machine is stable and wheelchocks are in place.

3. It is important that all protective devices are properlymaintained and repaired if necessary.

4. Wear the necessary personal protective equipmentwhen operating a power stumper (e.g., head, ear,eye, hand and foot protection).

5. Warn people to stay away, using signs and warningbarriers.

6. If, for any reason, the operator must leave themachine, the work must cease, the machine mustbe stopped and the key must be removed.

7. Take small incrimental passes across the stumprather than large ones.

8. When completed, clean up the area and fill in thedepression.

1102 HAULING OF BRUSH

All limbs under 10 cm (4 in.) in diameter are consid-ered to be brush. To haul brush away from the job site,certain procedures should be followed:

1. Place brush in a convenient location for loading.

2. Place butt ends in the same direction for ease ofhandling.

3. Place "brush ropes" on the truck platform beforestarting to load. They can be used to secure thebrush while transporting and to make unloadingeasier.

4. Load on the side of the truck opposite to traffic flow.

5. Cover and secure the load with a tarp while trans-porting.

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1103 WORK ON CUSTOMER PREMISES

Good public relations are important in any industry andgood housekeeping will help create that relationship.The supervisor should ensure a safe working environ-ment for workers and the general public to preventinjuries and damage to property. Make arrangementsto remove piled wood on the day it is cut. Offer any cuttimber to property owners for personal use. If theowner does not want the wood, dispose of it by othermeans and in accordance with company policy.

Use barricades, warning signs and common courtesyto warn the general public of any hazards that couldexist (e.g., falling limbs, chipper exhaust, chain sawoperation, etc.).

Utilize ground support to maintain a safe work zone.

1104 TOOL CLEAN UP

Inspect your tools/equipment and take certain precau-tions with them at the end of the work shift, whenchanging locations, or when not in use.

Chainsaws

1. Allow the saw to cool before working on or storingit.

2. Wipe the saw to remove any oil, sawdust, etc.

3. Touch up the cutting chain with the proper file. Useeye and hand protection.

4. Visually inspect the bar.

5. Protect the saw blade by covering it with the chain-saw guard.

6. Secure the saw on the vehicle while in transit.

7. Store saws in a well ventilated area.

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Hand Saws1. Clean off any tree sap with an approved cleaner.

2. Inspect the saw for broken teeth and missing boltsin the handle.

3. Touch up the cutting teeth with the proper file. Useeye and hand protection.

4. Check the sheath for any missing rivets or wornstitching and repair if necessary.

5. Store the saw in an approved sheath (scabbard).

Pruners1. Inspect for any damage or loose fittings on the

pruner.

2. Remove any material on the pruner (e.g., tree paint)with an approved cleaner.

3. Inspect the rope and pulley.

4. Clean the insulated insert with an approved cleaner.

5. Ensure the pruner head is hooded.

6. Store either in a container or secure in a tool rackon the vehicle.

Clothing1. Discard contaminated clothing, if cleaning will not

decontaminate.

2. Clean neoprene gloves, aprons, etc. with mild soapand warm water.

3. Discard breathing apparatus cartridges when spentor clogged.NOTE: When using chemicals, always check for

proper labelling and safe handlingprocedures.

T 905-625-0100�•�T 1-800-263-5024�•�F [email protected]�•�ihsa.ca

© Copyright 2011. All Rights ReservedInfrastructure Health & Safety Association

SPG8

• Bare Hand Live Line Techniques

• Conductor Stringing• Entry and Work in a

Confi ned Space• Excavating with

Hydrovacs in the Vicinity of Underground Electrical Plant

• High Voltage Rubber Techniques up to 36 kV

• Hydraulics

• Ladder Safety • Line Clearing Operations• Live Line Tool Techniques • Low Voltage Applications • Pole Handling• Ropes, Rigging and

Slinging Hardware• Temporary Grounding

and Bonding Techniques• Underground Electrical

Systems

Available Safe Practice Guides

Safe Practice Guide - IHSA

Documents