Advanced tree felling

Welcome to Husqvarna’s Chainsaw Academy, Part 2: Advanced tree felling. The content presented here assumes that you have a basic understanding of chainsaw use in both theory and practice. It is intended for people who want to develop their knowledge to carry out complex and hazardous operations, such as working in a storm-felled, or fire-ravaged forest.

Here we cover the following advanced tree felling topics: tools, planning, and essential knowledge, as well as specific applications, such as leaning trees, special trees, processing a storm-felled forest and advanced cutting.

Advanced tree felling situations should only be handled by tree felling professionals with the correct knowledge, training and experience. And, as usual, be sure to follow laws and regulations in your area. If you are not confident that you can perform the work safely and efficiently, then do not proceed. Safety first – always!

Part 1Basic tree felling

Working with chainsaws

Chainsaw safety basics

Working with a chainsaw involves many different work situations with both simple and more complicated steps. The chainsaw is a very effective tool, but it can also be dangerous if used improperly. In order to avoid accidents and unnecessary strain, you should use the correct working techniques, the best possible safety equipment and a modern chainsaw with functioning safety features.

Filing the chain

The chainsaw and guide bar should be fixed in a position that ensures stability, and in a way that makes it possible for you to have both hands free for filing. The easiest way is to use a vice on a workbench to secure the guide bar. Make sure the chain is properly tensioned – preferably harder than while cutting – so that it doesn’t move around. For extra stability, you can always activate the chain break.

Planning and felling

How to prepare for felling a tree

It is important that you plan tree felling very carefully. Trees must be felled safely and in the direction that you want them to fall. Well-planned felling also makes it easier to continue with your planned work. The factor that first and foremost affects tree felling is whether there are major obstacles in the area (overhead lines, roads and buildings, etc.). Deploy warning signs if you know that the forestry area is crossed by a road or that a lot of people pass through the area every day.

How to use tree felling tools

The size of the tree determines which felling tools you need to use. For the smallest trees, you do not normally need the felling tools. Hand force is enough, possibly with a long pole. The felling wedge provides greater felling force than the different types of breaking bar. In extreme cases, you can use a rope and winch, which is the safest and most powerful way to fell a tree.

How to remove a hang-up tree

If you accidentally fell a tree into another – always start by taking a break and thinking through the situation calmly. Removing a trapped tree is always a hazardous undertaking and there is no need to rush. Choose the safest solution to the problem even if it takes longer. There are several options. Do not be afraid to call for help – your safety is more important than anything else.

Limbing and crosscutting

How to crosscut a tree

Cutting up a tree trunk into desired lengths can be complicated. For example, the trunk might be very thick; be on a slope; or is lying directly on the ground. Before you begin, carefully consider the condition of the trunk, the stresses that are affecting it, and how the log end will move when you cut through it. Plan the crosscutting procedure carefully, especially for larger logs. An incorrect work technique can be dangerous and cause the trunk to split or the guide bar to become pinched.

Trunks located on a sharp slope

Trees standing on a slope should preferably be felled up the slope so that work can proceed as safely as possible. When working a trunk that is lying on a sharp slope, always stand at the top side of the trunk. Never stand where there is a risk that logs or the whole trunk roll or slide towards you. To support the trunk, keep the hinge intact if there is one, and keep locking branches in place when working.

Part 2Advanced tree felling

Tools

Felling wedges

In many ways, felling wedges are the humble heroes in advanced felling situations, providing remarkable lifting force for greater control and precision. As you know from your basic training, wedges are inserted before the felling cut is complete, and are knocked in with an axe or an impact breaking bar. They help the tree fall in the direction of the notch cut by lifting the tree in that direction. Wedges also prevent the tree from pinching the saw, or leaning back on the saw, while making a back cut. In addition, wedges can be used to release a pinched saw.

Planning

Work Plan

Safety is built on knowledge. Once you have inspected the worksite and the tree, and assessed the risks, it’s time to develop the work plan. But remember that identifying and mitigating risks is a continuous effort at every stage in your planning. For example, be aware that the work methods you decide on as part of your work plan, also have risks that you need to deal with. The same is true for the tools you need to complete the task. Know the risks!

Communicate and Prepare

Be sure to communicate the worksite risk assessment and the work plan to all members of your team. Everybody should understand the risks and the plan for executing the task. It is also now time to prepare yourself, your team and the worksite – taking preventive actions based on the risk assessment. Put on your PPE, block off the worksite, clear your escape routes, position your vehicle so that it is ready for immediate departure in case of urgency, and get out the first aid kit before you start working. Once all team members have signalled a “thumbs up”, the time has come to execute the task.

Execute and Adjust

Now that you have carefully performed and followed each step in the work plan, you and your team are ready to execute the plan. This is where all the time and effort spent with the worksite inspection, the VTA, the worksite risk assessment and deciding on a proper work method really pays off. Making it more likely that you can complete the task safely. But remember: a good plan is not written in stone. More likely than not, you will have to adjust it as you carry out your work.

Essential knowledge for advanced tree felling

Lifting height & Felling force

The lifting height is the distance that the felling tool must push apart the felling cut before the tree falls on its own accord. The diagram shows the required lifting height for different tree diameters, including the saw cut. The values apply to Nordic tree species and trunk forms and should be considered as a guide, not as exact figures. Using the diagram you can, for example, see if you need several wedges in height to bring down the tree.

Leaning trees

Felling across the lean

A tree that leans across the direction of felling wants to fall to the side of your line of sight. You should compensate for the side lean by aiming by the same distance in the opposite direction as the tree is leaning. For example: if the tree leans 1 m to the right, aim at least 1 m to the left. Insert the felling wedge at an oblique angle from the side of the lean allowing the felling force to shore up the tree.

Special trees

Split and crack prone tree species

Splits in the trunks are primarily caused by the internal natural tension in the wood on hard or very hard wood, such as beech. During felling or cutting much of the tension is released. Wood that splits during felling can be a major safety hazard. Split wood can also result in timber losses and, consequently, financial losses. Here are two methods you can use to avoid splitting.

Processing of storm-felled forest