Directional tree felling is the calculated process of guiding a tree to fall precisely into a planned zone. This method is employed to protect nearby structures and property and to ensure the safety of the person performing the cut. Controlling the direction requires specific, technical cuts that utilize the tree’s wood fibers to act as a hinge and a guide rail. Success relies on thorough preparation, accurate measurements, and careful execution of the cuts, rather than simple brute force.
Essential Preparations and Safety
Before any cutting begins, a comprehensive assessment of both the tree and its surrounding environment must be completed. Determining the tree’s natural lean is a primary task, as it tends to fall toward its heaviest side, usually due to an uneven canopy or slope. This lean can be visually assessed by standing back and holding a straight object at arm’s length to check the alignment of the trunk against a vertical line.
The trunk must be checked for rot, decay, or cavities, as these weaknesses can cause the tree to split or fall prematurely. Environmental factors, such as the proximity of power lines, buildings, or fences, must be identified to define a safe target drop zone and a clear safety perimeter. Once the intended fall path is established, the area around the tree’s base needs to be cleared of brush, debris, and low-hanging limbs to ensure unobstructed movement during the cutting process.
Personal protection is non-negotiable when operating a chainsaw. Mandatory PPE includes a hard hat, eye protection, and ear protection to mitigate noise damage. The user must wear cut-resistant gear, such as chainsaw chaps or trousers, and sturdy steel-toed boots to protect against accidental contact with the moving chain.
The final preparation involves establishing a clear escape route before the saw touches the wood. This route must be located diagonally away from the planned line of fall, typically at a 45-degree angle opposite the direction of the notch. Two such paths should be cleared to allow the operator to rapidly step back and retreat safely as soon as the tree begins to move.
Understanding the Directional Notch
The directional notch (face cut or undercut) is the first and most crucial cut for establishing the tree’s fall direction. This wedge-shaped cut removes wood from the side of the tree facing the intended target zone, effectively pre-determining the point of collapse. The entire face of the notch must be perfectly aligned with the desired fall path, as even a small misalignment at the trunk can translate into the tree missing its target by several feet at the top.
Creating the notch involves two cuts that meet precisely to remove a wedge of wood. The top cut is made at an angle, and the bottom cut is made horizontally, meeting the top cut at the apex of the notch. For maximum control, the open face notch, which has an opening angle of 70 degrees or greater, is the preferred method, as it keeps the guiding hinge intact for a longer duration of the fall.
The depth of the notch determines the length of the hinge and is a precise measurement relative to the tree’s diameter. The cut should extend into the trunk approximately one-fifth to one-third of the tree’s diameter. Cutting deeper than one-third is counterproductive, as it removes too much wood, which can cause the trunk to prematurely break or split, leading to a loss of directional control.
Executing the Back Cut and Hinge Control
The back cut (felling cut) is made opposite the directional notch and is the final cut that initiates the tree’s fall. It must be executed as a perfectly horizontal cut, running parallel to the bottom cut of the notch. This cut leaves a strip of uncut wood between the back cut and the notch, which is known as the hinge.
The back cut must be positioned slightly higher than the horizontal cut of the notch, creating a step of about one to two inches. This elevation difference is a safety feature that helps prevent the butt of the tree from kicking back over the stump toward the operator as the tree begins to fall. Failure to maintain this step, or cutting the back cut too low, can cause the tree to sit back on the stump.
The hinge is the single most important component for directional control, acting as a pivot point and a guiding rail. The width of this hinge, measured along the direction of the fall, should be maintained at approximately 10% of the tree’s diameter. If the hinge is too thin, it will break too quickly, resulting in an uncontrolled fall; if it is too thick, it may prevent the tree from falling completely. The length of the hinge should be at least 80% of the tree’s diameter to provide adequate structural control throughout the fall. As the saw nears the hinge, the operator must watch for the first signs of movement, immediately disengaging the saw and moving swiftly along the pre-cleared escape path.
Using Felling Aids for Directional Control
In situations where a tree has a slight lean away from the desired direction, or when extra assurance is needed, supplemental tools can be used to influence the fall. Felling wedges are the most common aid, designed to prevent the saw bar from becoming pinched as the back cut progresses. These wedges, typically made of plastic or aluminum, are inserted into the back cut and hammered with a maul.
Driving the wedges into the cut generates a lifting force that pushes the tree’s center of gravity up and over the hinge, directing it toward the notch. Even a small lift at the base can translate into a movement of several feet at the tree’s top, helping to counteract a slight back lean or an unbalanced crown. It is common to use multiple wedges, alternating between them to maintain continuous pressure until the tree commits to the fall direction.
For trees with a significant lean away from the target zone, a rope and pulling system provides a safer, more forceful option. This system involves securing a rope or cable high on the trunk (typically at the second third of the tree’s height) and running it through a mechanical advantage system like a winch or pulley anchored to another tree. Tension is applied to the rope after the notch is cut, and then again as the back cut nears completion, ensuring the tree is pulled over the hinge and into the desired path from a safe distance outside the fall zone.