Whether you are using Check this website a chain saw to cut firewood, trim trees or harvest large timber, you will be performing three basic operations: felling, limbing and bucking. Felling involves cutting a standing tree and dropping it in the place you want it. Limbing is the removal of the branches from either standing or downed trees. Bucking is the process of cutting a downed tree into appropriate lengths.
Felling a tree
Felling a tree can literally make or break your day. Landing a tree where you want it facilitates the rest of your operations. Many people cutting firewood have dropped trees on their pickup trucks.
Examine the tree and its surroundings
Note any uneven distribution of branches in the tree crown, lean of the trunk and signs of rot or decay. Inexperienced tree cutters should never attempt to cut trees that are decayed or rotted inside or that are leaning or otherwise under tension. Such trees are at greater risk of snapping or splitting while being cut, which could cause serious or fatal injury to the cutter or bystanders.
If power lines are in the vicinity of the tree, do not attempt to fell the tree unless you are absolutely certain that doing so will not interfere with them. If the tree must be removed and you suspect felling it will affect a power line, call the power company. They will have the expertise and equipment to remove the tree safely.
Plan two escape paths
Two escape paths from a tree being felled.
Figure 1. When preparing to fell a tree, plan two escape paths. Clear the paths of all obstacles before making your first cut. (Used with permission of STIHL Inc.)
Plan two escape paths (B) opposite the planned direction of the fall of the tree (A) and at about a 45 angle from each other (Figure 1). Remove all obstacles from the paths. Place all tools and equipment a safe distance away from the tree but not on the escape paths. Select a place to set the chain saw in case of emergency. Never run while holding a chain saw, operating or not. Rather, turn off the chain saw and set it down before making your escape.
Make the cut
Clear a safe work area around the base of the tree. Remove limbs, underbrush and other obstructions, being sure to keep your escape paths clear.
Ensure all bystanders are a safe distance from the base of the tree to be felled, at least 1-1/2 times the height of the tree, before the first cut is made.
For trees 6 inches in diameter or less, make one cut through the trunk. For larger diameter trees, the inexperienced chain saw operator should make two basic cuts: the undercut and the back cut. Advanced cutting techniques, such as plunge cutting, should only be done by experienced, professional loggers.
Undercut
The undercut serves as the guiding or aiming slot for the tree. Basically it is a V-shaped notch placed on the side of the tree in the direction of falling (Figure 2). Either a standard undercut (Figure 2a) or a reverse undercut (Figure 2b) can be used. Typically the first cut is made parallel to the ground and then the slanting cut is made.
Three types of undercuts.
Figure 2. Three types of undercuts. Note that in each case, the back cut is slightly (1 to 2 inches) above the hinge point of the undercut.
The direction a tree falls.
Figure 3. The direction a tree falls can be closely controlled with properly made undercuts and back cuts.
A modified undercut known as an open-faced undercut has become popular in many areas (Figure 2c). Introduced by Scandinavian felling specialists, this cut is easier to make, provides good guidance and has additional safety features. Instead of ending up with a 45-degree opening, the undercut provides a nearly 90-degree opening. When the tree starts to fall, this modified undercut allows additional room for the tree to fall before the top and bottom of the undercut come together.
Back cut
For all three undercuts, the back cut is made on the opposite side of the tree, slightly above the hinge point of the undercut (Figure 2). The back cut releases the stresses on the back of the tree, allowing the tree to fall. Never make the back cut lower than the undercut because that reverses the roles of the two cuts. Never cut through the undercut because that will cause you to lose all control over the tree.
As the saw nears the undercut, leave a small amount of wood to serve as the “hinge” or “holding” wood (Figure 3). The tree actually pivots on this hinge, and the width and angle of the hinge can be used to guide the direction of the tree’s fall. Because of the angled hinge, the tree will start to fall on the narrow section of the hinge while the wood at the thicker section of the hinge is still intact. The tree is therefore pulled toward the thick section. Making these cuts is an art and requires practice.
Limbing a tree
When removing unwanted limbs from standing timber, the basic safety rule is: Never limb above your shoulders; that is, do not attempt to cut off branches above the height of your shoulders. Cutting above your shoulders requires that you hold the chain saw at or near arm’s length, and you lose control over the saw in this position.
Bucking a tree
The process of cutting a tree into usable lengths is called bucking. Bucking often occurs as a tree is being limbed, such as when the limbs of the crown are to be used as firewood. When cutting firewood, make sure you know the needed length of wood before you leave home. When cutting full-size products, such as sawlogs and veneer logs, you must cut logs longer than the final product to leave a trim allowance. For an 8-foot log, a trim allowance of 4 to 6 inches is common. Many bucking cuts are angled, and the trim allowance allows the ends of the boards to be cut square at the mill to the desired board lengths.
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