Directional tree felling is a precise procedure designed to guide a falling tree to a specific target area, prioritizing safety and the protection of surrounding property. Controlling a tree’s descent relies on pre-planning, physics, and specialized cutting techniques. This methodical approach involves assessing the tree’s characteristics and employing cuts that steer the trunk toward the intended landing zone, transforming a potentially unpredictable event into a controlled mechanical action.
Assessing the Tree and Clearing the Fall Zone
The process requires a comprehensive assessment of the tree and its environment before any cut is made. Determining the tree’s natural lean is important, as the center of mass strongly influences the direction of fall. This lean can be estimated using a plumb line, which reveals how far the tree’s center of mass deviates from its base.
A visual survey must also identify hazards within the crown, such as dead limbs (“widow-makers”), or overhead utility lines. Wind direction and speed must be considered, as moderate gusts can push the tree off course. Defining the intended landing zone allows for the selection of a precise felling line that avoids property or other trees.
Two clear escape paths must be established before cutting begins. These paths should be diagonally away from the planned fall line, specifically at a 45-degree angle to the rear of the stump. Clearing these routes of debris or trip hazards ensures a quick retreat. The area directly behind the stump is dangerous when the tree falls, making this prepared path essential for safety.
The Importance of the Hinge and Directional Notch
The directional notch, or face cut, is the aiming mechanism created on the side of the trunk facing the intended landing zone. This wedge-shaped opening should be about one-third of the tree’s diameter in depth. The notch allows the tree to fall without binding on the stump, establishing a point of controlled collapse.
The two main types are the Conventional notch (45-degree angle) and the Open-Face notch (70 to 90 degrees). The Conventional notch causes the hinge to break early. The Open-Face notch is preferred because its wider opening ensures the hinge remains intact longer, guiding the tree through a greater portion of its fall.
The hinge is the strip of uncut wood remaining between the directional notch and the final cut. It acts like a mechanical hinge, steering the tree and regulating the speed of the fall. For effective control, the hinge should be of uniform width and approximately 80 percent of the tree’s diameter. Maintaining the integrity of this wood is important, as premature failure results in an uncontrolled fall.
Executing the Back Cut and Mechanical Aids
Once the directional notch is complete, the final step is the back cut, made horizontally on the side opposite the notch. This cut is positioned slightly higher than the apex of the notch, typically by one to two inches. This offset creates a “step” on the stump, preventing the butt of the falling tree from sliding backward, an event known as “stump jump.”
The back cut must stop short of the notch, leaving the hinge wood intact to guide the fall. As the cut nears completion, felling wedges are inserted to provide directional leverage. These wedges are hammered into the back cut, lifting the tree’s center of gravity and forcing movement in the desired direction. Wedges are useful for overcoming slight back or side leans and prevent the saw chain from becoming pinched.
As the wedges are driven in and the tree begins to tip, the operator must immediately retreat along one of the pre-cleared 45-degree escape paths. Maintaining visual contact with the falling tree while retreating is important to monitor for unexpected limb breakage or debris.
When to Call a Professional
While the principles of directional felling are straightforward, certain situations require certified professionals. Trees located near power lines or leaning heavily against a structure increase the potential for catastrophic property damage or electrocution.
Trees exhibiting significant signs of decay, such as large cavities, fungal growth, or internal rot, have compromised wood strength. This internal damage makes the wood fibers unpredictable, potentially causing the hinge to fail prematurely or the trunk to split (“barber chair”). Furthermore, trees exceeding 60 feet or those whose crowns are entangled with surrounding limbs require specialized equipment and advanced rigging techniques. In these complex scenarios, the expertise of an insured arborist is necessary for safety.