Elements and Performance Criteria

The Range of Variables explains the contexts within which the performance and knowledge requirements of this standard may be assessed. The scope of variables chosen in particular training and assessment requirements may depend on the work situations available.

What OHS hazards may be identified in the work area?
Hazards may include solar radiation, dust, noise, and damp conditions, sharp/blunt cutting tools and equipment, moving machinery, slopes, water, rock, undergrowth, depressions/holes, falling branches and debris, tangled ropes, power lines, power surges, interruption or disturbance of electricity supply, placement of ladders, climbing ladders, ladder instability and loss of balance.

What suitable controls are likely to be implemented?
Suitable controls may include procedures for handling, transporting and storing petrol, oils, and chemicals; appropriate personal protective clothing and equipment such as rubber soled/leather boots, high visibility vest, cut resistant leg protection, gloves, helmets, goggles, safety harnesses, sun hats, hearing protection, face shields and sunscreen lotion; signage and barriers, approved ladders and ropes, safe operation and maintenance of machinery and equipment, safe procedures for working outdoors, correct manual handling techniques, basic first aid and emergency procedures training, and a two-way radio or mobile phone on site.

What legislation, local by-laws and regulations may be relevant to tree removal?
Legislation may include local government by-laws and government legislation such as the Environmental Protection Act, Tree preservation orders, Significant tree registers and/or legislation, Notification orders, Australian Standards for plant and equipment and traffic control devices, and regulations governing the proximity of powerlines to trees.

What removal method is likely to be employed?
Removal methods may include felling or dismantling.

What tools, equipment and machinery are likely to be used in the removal process?
Tools, equipment and machinery may include axes, wedges and wedging hammers, hand or power winches, pruning tools, chainsaws, elevated platforms, cherry pickers, cranes, ladders, wood chippers, stump grinders, skid steer loaders, work ropes, harnesses, lifelines, climbing spurs, prussik loops, carabiners, flip lines/pole straps, "D" shackles, pulleys, hobbs, and trifors

How might tools, equipment and machinery be prepared for use?
Preparation may include checking for wear and tear and defects in ropes, checking of working loads and breaking strain ratings of ropes, pre-operational checks of powered equipment and machinery, sharpening of blades and chains, and the cleaning of dust and accumulated wood fibres from tools, equipment and machinery.

In what situations might dismantling be employed to remove trees?
Dismantling may be employed where a tree is too high or wide, or directly above a target. Dismantling may involve the use of elevated platforms or tree climbers, cutting sections of branches and trunks and throwing them into a drop zone, or lowering branches and trunk sections to ground level using ropes.

How are suspended, wind thrown or damaged trees likely to be stabilised?
Stabilising may include cross cutting or propping. Suspended trees may be mechanically removed by winches or hand levers. Stabilising may be exercised to minimise the risk of a building or structure giving way and to prevent limbs, which are under pressure, "kicking back" as any tension is released.

What branch releasing cuts are likely to be employed in the cut and drop method of dismantling?
Branch releasing cuts may include a single top cut, an undercut then a top cut, a box cut, a scarf undercut then a top cut, and a spearing cut.

What type of ropes are likely to be used?
Types of ropes may include polyamide (nylon), polypropylene and polyester.

What rigging techniques are likely to be employed to lower branches and trunk sections?
Rigging techniques may include using a branch as friction, setting a pulley or false crotch, setting the rope above branches to be removed, pulling a large section of trunk to ground level, lowering block sections, speed lining and vertical speed lines.

In what situations might felling be employed to remove trees?
Felling may be employed where a tree can be felled without damaging or getting hung up in another tree, or causing damage to a target (e.g. a building). In a confined situation this may entail the rigging of "head" and "stay" ropes to keep positive control of the felled tree and to ensure it lands into its designated drop zone.

What directional felling techniques are likely to be used to remove trees?
Directional felling techniques may include back release, quarter cut, tongue in grove and large tree diameter method, and each of these may utilise the scarf, the back cut, holding wood, wedges, boring cuts, release cuts and plunge cuts.

How is plant material and debris likely to be disposed of?
Disposal methods may include burning, chipping, shredding, mulching and composting.

How may the height of the tree be determined?
The height of a tree may be determined with a scientific instrument such as a clinometer or in "A Field Guide to the Trees of Britain and Northern Europe". Mitchell describes a method that requires a 30cm ruler and another person.

What evidence is required to demonstrate competence for this standard as a whole?Competence in implementing the removal of trees in confined spaces requires evidence that a person can prepare trees for removal, fell or dismantle trees, and have the work completed according to enterprise guidelines.The skills and knowledge required to remove trees in an urban landscape must be transferable to a different work environment. For example, this could include different tree species, locations and removal techniques.
What specific knowledge is needed to achieve the performance criteria?

Knowledge and understanding are essential to apply this standard in the workplace, to transfer the skills to other contexts, and to deal with unplanned events. The knowledge requirements for this competency standard are listed below:

identification and evaluation of structural defects in trees
procedures for calling emergency services at the work site
first aid and rescue procedures applicable to tree work
safe working limit of all climbing, rigging and lowering equipment
an awareness of the environmental implications of soil disturbance and land clearance.

What specific skills are needed to achieve the performance criteria?

To achieve the performance criteria, appropriate literacy and numeracy levels as well as some complementary skills are required. These include the ability to:

dispose of plant material and debris in an environmentally safe and sensitive manner
minimise noise, dust or high activity vehicle traffic to prevent nuisance-level environmental disturbance
calculate tree height and weights of branches and trunk sections
advanced climbing and rigging techniques
use and control elevated work platforms.

What processes should be applied to this competency standard?There are a number of processes that are learnt throughout work and life, which are required in all jobs. They are fundamental processes and generally transferable to other work functions. Some of these are covered by the key competencies, although others may be added. The questions below highlight how these processes are applied in this competency standard. Following each question a number in brackets indicates the level to which the key competency needs to be demonstrated where 0 = not required, 1 = perform the process, 2 = perform and administer the process and 3 = perform, administer and design the process.
Communicating ideas and information
Information associated with the job, such as estimated completion dates and removal costs may be communicated with management and/or the client. (2)

Collecting analysing and organising information
Information regarding the removal program to be implemented may need to be collected, analysed and organised into a logical sequence. (2)

Planning and organising activities
Activities may need to be planned and organised according to OHS procedures and guidelines. (2)

Working with others and in teams
Removing trees in confined spaces may involve working with other members of a team to complete the removal program. (2)

Using mathematical ideas and techniques
Mathematical techniques may be applied when estimating and calculating tree height and branch weights and sizes, in particular when calculating safe working loads. (2)

Solving problems
Problem-solving skills may need to be applied if any of the climbing equipment is faulty and needs to be replaced. (2)

Using technology
The use of technology may need to be applied when using machinery such as elevated work platforms and stump grinders. (2)