Remove branches and breakdown crowns using a chainsaw — City & Guilds Limited Occupational Qualification Horticulture & Land Management Revision
This subtopic focuses on the practical skills required to safely remove branches and dismantle tree crowns using a chainsaw from the ground or an elevated
Topic Synopsis
This subtopic focuses on the practical skills required to safely remove branches and dismantle tree crowns using a chainsaw from the ground or an elevated platform. Learners must apply cutting techniques to control branch sections, observe safe working practices, and manage hazards as per current industry legislation and good practice. Competence in this area is essential for arboricultural operations and is assessed through practical demonstration of sequential breakdown cuts, appropriate use of aids, and adherence to risk assessment protocols.
Key Concepts & Core Principles
- Pre-operational checks: Before any cutting, you must inspect the chainsaw for damage, check chain tension, sharpness, and oil levels, and ensure personal protective equipment (PPE) such as chainsaw trousers, helmet, visor, gloves, and boots are worn correctly.
- Cutting techniques: The 'sink cut' (a notch cut) and 'back cut' are used to control the direction of branch or stem fall. The sink cut removes a wedge of wood to guide the fall, while the back cut is made on the opposite side to sever the hinge wood.
- Crown breakdown sequence: When dismantling a crown, always work from the top down, removing smaller branches first to reduce weight and prevent binding. Use a 'step cut' for larger limbs to avoid tearing bark.
- Risk assessment: Identify hazards such as overhead power lines, uneven ground, wind, and the tree's condition (e.g., decay, cracks). Establish a safe work zone and escape route before starting.
- Kickback prevention: Kickback occurs when the chain at the nose of the bar contacts an object. Avoid cutting with the tip, keep the chain sharp, and maintain a firm grip with both hands.
Exam Tips & Revision Strategies
- Verbalize your actions throughout the assessment – state what you are checking, why you are cutting in a certain way, and how you are managing risk; this demonstrates underpinning knowledge even if a cut is not perfect.
- Before each cut, pause to identify compression and tension forces; explain to the assessor which part of the guide bar you will use and why, showing deep understanding of wood loading.
- Always start with a 360-degree site walk and a ‘tree risk’ narrative, ticking off each hazard like utilities, uneven ground, and escape routes; this establishes methodical working from the outset.
- Keep the chainsaw well maintained and ensure the chain is correctly tensioned; a loose chain or blunt cutters will compromise control and attract negative marks.
- Practice efficient movement: apply the chain brake, place the saw on the ground or at idle, and only then remove debris; smooth, unhurried pace conveys competence.
Common Misconceptions & Mistakes to Avoid
- Learners often cut too deeply on the tension side of a branch, causing the saw to become trapped or the branch to split and tear bark from the main trunk.
- A frequent oversight is failing to check that the chain brake is engaged when moving between cuts or repositioning, which leads to automatic failure in assessment.
- Candidates underestimate the swing and bounce of branches upon separation, resulting in loss of control and potential injury; they do not anticipate the branch’s movement.
- Many learners neglect to consider the wind direction and strength, misjudging the landing area for cut branches and creating avoidable hazards.
- There is a tendency to overload the chainsaw's capacity by attempting to cut sections that are too large, leading to saw kickback or loss of balance.
- Students often forget to refuel the chainsaw in a safe area, violating regulations on handling petrol and hot machinery near the work zone.
Examiner Marking Points
- Award credit for demonstrating a thorough site and tree hazard assessment, including identification of overhead power lines, deadwood, and target areas, before starting work.
- Expect the candidate to consistently wear the correct personal protective equipment (PPE) – chainsaw trousers, boots, helmet with visor and ear defenders, and appropriate gloves – throughout the task.
- Credit should be given for selection and application of the correct cutting sequence, such as step cuts, sink cuts, or letterbox cuts, ensuring control of the branch and avoiding damage to the main stem.
- Look for evidence that the candidate maintains a safe working position, uses the chain brake when moving, and positions themselves to avoid the line of cut and falling material.
- Require the candidate to demonstrate safe handling of the chainsaw during awkward or undercut branches, using the top and bottom of the guide bar appropriately to manage tension and compression wood.
- Assess that the candidate correctly manages the lowering or free-falling of cut sections, communicating effectively with ground staff and ensuring the drop zone is clear.