AHCARB206
Operate and maintain stump grinding machines


Application

This unit of competency describes the skills and knowledge required to operate motorised stump grinding machines to remove tree stumps from the ground.

This unit applies to individuals who undertake defined activities with specialised tools and methods, work in a structured context, apply knowledge and skills to demonstrate autonomy and limited judgement, and provide solutions to a limited range of predictable problems. Work is implemented with low risk work procedures, in accordance with manufacturers recommendations and to comply with Safe Work Method Statement documentation.

Licensing, legislative, regulatory, or certification requirements apply to this unit in some states and territories at the time of publication, and may differ according to jurisdiction. Specific determination should be sought through the relevant State or Territory. Works involving this unit of competency may be subject to local tree protection and preservation laws, and the relevant content of applicable Australian Standards


Elements and Performance Criteria

Element

Performance criteria

Elements describe the essential outcomes.

Performance criteria describe the performance needed to demonstrate achievement of the element.

1. Prepare for stump removal operations

1.1 Determine site location and details and clarify with supervisor

1.2 Determine the depth below ground of stump grinding works

1.3 Determine and confirm location and depth of above-and-below-ground services

1.4 Unload stump grinder machine

1.5 Undertake a site-specific risk assessment by identifying work health and safety hazards and assessing risk

2. Carry out pre-operational and safety checks

2.1 Check maintenance log is complete and up to date

2.2 Check belts are appropriately tensioned and in good order

2.3 Check teeth are sharp

2.4 Check no teeth are missing or loose

2.5 Check tyre pressure is correct or tracks are appropriately tensioned

2.6 Check levels of oils and fluids

2.7 Check hoses

2.8 Check brakes are operational

2.9 Check cutter head rotates freely and is not obstructed

3. Check stump grinder safety features

3.1 Check guards for belt, power take-off (PTO) and grinder head are in place

3.2 Check kill switch clearly identifiable and working

3.3 Check that dead-man is working if fitted

3.4 Check debris curtain present and in good order

3.5 Check dust suppression system is working if fitted

4. Complete preparations for work

4.1 Select and use appropriate personal protective equipment

4.2 Confirm first aid and emergency personnel, equipment and procedures

4.3 Expose stump surrounds manually and check for and remove foreign bodies

4.4 Moisten surrounds as required

4.5 Record and implement work health, safety, site, environmental and traffic control measures

5. Position stump grinder

5.1 Determine exclusion zone for work operations

5.2 Isolate exclusion zone with barriers and signs

5.3 Position machine level within recommended ranges to avoid rollover

5.4 Avoid holes with machine wheels

5.5 Position machine to minimise impact from flying debris

5.6 Position operator in low risk position

5.7 Position operator to provide a clear view of the stump

5.8 Locate safety screens as required

6. Undertake removal operations

6.1 Communicate with work team during operations using voice, hand and whistle signals

6.1 Confirm work zone cleared prior to starting cutter head

6.3 Plan to complete a series of grinds across the stump

6.4 Start cutter head

6.5 Stop work if exclusion zone is breached and disengage cutter head if required

6.6 Position cutter head over stump

6.7 Engage cutter head into stump surface

6.8 Maintain engine speed in revolutions-per-minute (RPM)

6.9 Ensure grinding process is accurate, smooth and ergonomic

6.10 Grind stump to recommended depth of cut on each cutting pass

6.11 Ensure the cut size of each pass is not excessively deep causing the machine to labour excessively or to stall

6.12 Grind stump to predetermined spread and depth

6.13 Operate equipment without damaging underground services and surrounding areas

7. Remove grindings

7.1 Reposition machine away from ground stump

7.2 Disengage cutter head

7.3 Wait and remain clear of cutter head until cutter head stops moving

7.4 Remove build-up of grindings

8. Perform ongoing grinding operations

8.1 Make check in calls at prearranged times

8.2 Inspect grinder as required between stumps and when refuelling

8.3 Shutdown immediately if abnormal vibration or noise develops

8.4 Stop the engine before refuelling and allow engine to cool as required

8.5 Follow Safe Work Method Statement instructions for refuelling

8.6 Replace and secure fuel cap before restarting

8.7 Disengage cutter head and ensure a complete stop before moving to a new stump

9. Complete stump removal operation

9.1 Back-fill stump hole to original ground level

9.2 Maintain clean and safe work area throughout work and upon completion

9.3 Collect waste material and dispose of or recycle in a manner causing minimal environmental damage

9.4 Clean, maintain and store tools and equipment

9.5 Perform basic maintenance, including sharpening grinder and replacing teeth as required

9.6 Load grinder in accordance with Safe Work Method Statement

9.7 Secure grinder for transport

9.8 Update records of operator usage in log record

9.9 Update records of maintenance and replacement items

Evidence of Performance

The candidate must be observed removing stumps using a motorised stump grinder using low-risk work procedures. The candidate must be assessed on their ability to integrate and apply the performance requirements of this unit in a workplace setting. Performance must be demonstrated consistently over time and in a suitable range of contexts.

The candidate must provide evidence for and demonstrate:

determining site location and details and clarifying with supervisor

determining the depth below ground of stump grinding works

determining and confirm location and depth of above-and-below-ground services

unload stump grinder machine

undertaking a site-specific risk assessment by identifying work health and safety hazards and assessing risk

checking maintenance log complete and up to date

checking belts appropriately tensioned and in good order

checking teeth are sharp

checking no teeth are missing or loose

checking tyre pressure is correct or tracks are appropriately tensioned

checking levels of oils and fluids

checking hoses

checking brakes are operational

checking cutter head rotates freely and is not obstructed

checking guards for belt, power take-off (PTO) and grinder head are in place

checking kill switch clearly identifiable and working

checking that dead-man is working if fitted

checking debris curtain present and in good order

checking dust suppression system is working if fitted

selecting and use appropriate personal protective equipment

confirming first aid and emergency personnel, equipment and procedures

exposing stump surrounds manually and check for and remove foreign bodies

moistening surrounds as required

recording and implementing work health, safety, site, environmental and traffic control measures

determining exclusion zone for work operations

isolating exclusion zone with barriers and signs

positioning machine level within recommended ranges to avoid rollover

avoiding holes with machine wheels

positioning machine to minimise impact from flying debris

positioning operator in low risk position

positioning operator to provide a clear view of the stump

locating safety screens as required

communicating with work team during operations using voice, hand and whistle signals

confirming work zone cleared prior to starting cutter head

planning to complete a series of passes across the stump

starting cutter head

stopping work if exclusion zone is breached and disengage cutter head if required

positioning cutter head over stump

engaging cutter head into stump surface

maintaining engine speed in revolutions-per-minute (rpm)

ensuring grinding process is accurate, smooth and ergonomic

grinding stump to recommended depth of cut on each cutting pass

ensuring the cut size of each pass is not excessively deep causing the machine to labour excessively or to stall

grinding stump to predetermined spread and depth

operating equipment without damaging underground services and surrounding areas

repositioning machine away from ground stump

disengaging cutter head if risk of making unwanted contact

waiting and remaining clear of cutter head until cutter head stops moving

removing build-up of grindings

making check in calls at prearranged times

inspecting grinder as required between stumps and when refueling

shutting down immediately if abnormal vibration and/or noise develops

stopping the engine before refueling and allow engine to cool as required

following safe work method statement instructions for refueling

replacing and securing fuel cap before restarting

disengaging cutter head and ensure a complete stop before moving to a new stump

back-filling stump hole to original ground level

maintaining clean and safe work area throughout work and upon completion

collecting waste material and dispose of or recycle in a manner causing minimal environmental damage

cleaning, maintaining and storing tools and equipment

performing basic maintenance, including sharpening grinder and replacing teeth as required

loading grinder in accordance with safe work method statement

securing grinder for transport

updating records of operator usage in log record

updating records of maintenance and replacement items.


Evidence of Knowledge

The candidate must demonstrate knowledge of:

site hazard identification methods

site risk assessment systems

control measures for work health, safety, site, environmental and traffic control

personal protective equipment

communication systems using voice, hand and whistle signals

first aid

emergency procedures

methods of locating services

pre-operational checks of stump grinders including:

logs

belts

teeth

tyre pressure

oils and fluids

hoses

brakes

cutter head

guards

safety checks of stump grinders including:

guards for belt, power take-off (PTO) and grinder head

kill switch

dead man

debris curtain

dust suppression

exclusion zones

operation of stump grinders

cutter head engagement and disengagement

positioning of stump grinders and operator

work zone

methods of determining spread and depth of cut

recommended depths of cut

cutting plan

engine speed (rpm)

abnormal vibration

methods of back-filling

environmental implications of removal activities

appropriate methods of collecting waste material and disposal or recycling methods

basic maintenance of stump grinders

methods of sharpening stump grinders

methods of teeth replacement of stump grinders

records of operator usage in log record

methods of maintaining records for basic maintenance and replacement items.


Assessment Conditions

It is an industry requirement for competency in this unit that assessment includes a log record, verifying ten (10) hours of operating a stump grinder, and five (5) hours of unloading and loading, setup and pre-operational and safety checks, preparatory work, backfilling and cleaning up, sharpening and basic maintenance, performed by the candidate.

Assessment must be demonstrated consistently over time in a suitable range of contexts and have a productivity-based outcome. No single assessment event or report is sufficient to achieve competency in this unit.

Assessment may be conducted in a simulated or real work environment, however determination of competency requires the application of work practices under work conditions.

The mandatory equipment and materials used to gather evidence for assessment include:

equipment:

stump grinder

sharpening equipment

refuelling kit

spill kit

emergency communication system

personal protective equipment (PPE)

first aid and emergency kit

traffic management kit

signage – work zone

tree stumps

materials:

stump grinder operations form

hazard identification and risk control form

pre-operational and safety check form

emergency preparation form

work communications form

work records form

Assessors must satisfy current standards for RTOs in the assessment of arboriculture units of competency.

Assessment must be conducted only by persons who have:

arboriculture vocational competencies at least to the level being assessed

current arboriculture industry skills directly relevant to the unit of competency being assessed


Foundation Skills

Foundation Skills essential to performance are explicit in the performance criteria of this unit of competency.


Range Statement


Sectors

Arboriculture (ARB)