Felling a tree that leans away from the desired direction of fall presents a significant challenge, requiring the precise application of mechanical force to overcome gravitational pull. The tree’s natural lean is governed by its center of gravity, which pulls the trunk toward the ground when supporting wood fibers are severed. Redirecting this force demands advanced techniques and specialized equipment to safely shift the tree’s balance point toward the intended landing zone. This process moves beyond standard felling methods and should only be considered by individuals with extensive training or professional arborists. The goal is to safely override the tree’s natural inclination using precise cuts and external tension, ensuring a controlled fall.
Pre-Cut Assessment and Safety Planning
The first step in any felling operation, particularly one involving a contrary lean, is a meticulous assessment of the tree and the surrounding environment. Determining the true center of gravity is important, which is done using a plumb line or weighted string to project the tree’s balance point to the ground. Trees leaning more than 15 degrees from vertical are considered high-risk and increase the difficulty of redirection. This initial evaluation must also identify all potential hazards within the tree’s fall radius, including power lines, nearby structures, and obstacles that could impede the fall or the operator’s escape.
Planning for an immediate retreat is equally important, as the moments following the final cut carry the highest risk. Operators must establish at least two distinct escape routes, cleared of debris and positioned at approximately a 45-degree angle away from the anticipated line of fall. This angular path allows the operator to quickly move away from the stump while remaining outside the dangerous kickback zone—the arc of the tree’s butt as it hinges backward. Personal protective equipment (PPE) is mandatory for this advanced task, requiring:
- A protective helmet.
- Hearing protection.
- Eye protection.
- Chainsaw chaps constructed with ballistic material to guard against accidental contact with the running chain.
Standard Felling Mechanics: The Hinge and Notch
The success of any directional felling technique relies on the fundamental mechanics created by the notch cut and the hinge. The notch, also called the face cut, is made on the side of the tree facing the intended direction of fall. It is composed of a horizontal cut and an angled cut that meet to remove a wedge of wood. The conventional notch removes approximately 20 to 25 percent of the tree’s diameter, with the cuts forming a 45-degree angle. This removed section establishes the precise line of fall and initiates directional control.
The hinge is the remaining uncut wood fiber connecting the stump to the trunk, located between the notch and the final back cut. This strip of wood acts as the physical steering mechanism, guiding the tree along the planned direction of fall and preventing premature twisting. For proper control, the hinge should maintain a uniform thickness across the entire diameter, typically measuring about one-tenth of the tree’s diameter. The back cut is made on the side opposite the notch and is aligned slightly above the horizontal cut of the notch. This alignment ensures the tree pivots smoothly over the hinge as the fibers begin to tear.
Advanced Techniques for Redirecting the Lean
Overcoming a tree’s natural lean requires introducing an external force that applies a mechanical advantage sufficient to counteract the existing momentum. One effective method involves applying tension using ropes, cables, or specialized winches rigged high on the trunk, ideally two-thirds of the way up the tree’s height. Placing the rigging point higher maximizes the leverage applied to the center of gravity. This translates a smaller force at the winch into a larger directional force at the tree’s base. The winch system is anchored to a separate tree or solid object in the desired direction of fall. Tension is applied before the back cut begins, ensuring the system is taut and ready to pull the tree over once the wood fibers are reduced.
The Bore Cut
The bore cut, or plunge cut, is a specialized technique used to establish the hinge and insert wedges before the back cut is fully released. This cut involves thrusting the tip of the saw bar horizontally into the trunk, cutting out the interior wood while leaving a strap of wood on the back side of the tree. The bore cut allows the operator to precisely control the thickness and length of the hinge. It also provides space to insert felling wedges without risking the tree prematurely sitting back on the saw bar. By leaving a small “trigger” section of wood uncut, structural integrity is maintained until the final moment of release.
Felling Wedges
Felling wedges are another powerful tool for redirecting a lean, used either with a winch or as the primary force for smaller degrees of lean. These wedges, typically made of high-impact plastic or aluminum, are driven into the bore cut or the partially completed back cut using a sledgehammer. Driving the wedges lifts the trunk off the stump, physically raising the tree’s center of gravity and pushing it against the lean toward the notch. This lifting action compresses the wood fibers on the side of the lean and facilitates the tree’s pivot over the hinge.
The execution sequence for redirecting a leaning tree must be precise and rapid to minimize the time the operator spends in the danger zone. After rigging the tension system and securing the anchor, the operator makes the face cut and then executes the bore cut to establish the hinge and insert the wedges. Tension is applied to the winch system. The final cut is made through the remaining trigger wood or back strap. The operator immediately retreats along the pre-cleared escape route as the external force, combined with the loss of wood fiber support, overcomes the natural lean and pulls the tree in the intended direction.