Cutting Trees Tools: Diagnosing and Solving Common Felling Failures

Using the wrong equipment during tree removal or heavy pruning is rarely just an inconvenience; it is a primary catalyst for catastrophic mechanical failure and severe injury. When a chainsaw binds in a kerf, a trunk splits prematurely, or a limb kicks back, the root cause is almost always a mismatch between the physical forces of the wood and the cutting trees tools deployed to manage them. Professional arborists do not rely on brute force. They diagnose the tension, compression, and shear forces within the timber and select specific tools to neutralize those forces safely.

This guide bypasses basic safety platitudes and focuses on advanced problem diagnosis. We will dissect the three most common felling and bucking failures—bar binding, barber-chair splits, and overhead kickback—and prescribe the exact tool specifications, measurements, and techniques required to solve them.

Evaluating Wood Tension and Compression Zones

Before diagnosing a specific tool failure, you must read the tree's load dynamics. Every leaning tree or suspended branch has a tension side (where wood fibers are stretched) and a compression side (where fibers are crushed together).

• Compression Wood: Found on the underside of a leaning branch or the side of a trunk leaning away from you. Cutting here first causes the kerf to close, trapping the saw bar.
• Tension Wood: Found on the topside of a branch or the side the tree is leaning toward. Cutting here first risks the wood snapping unpredictably, causing violent kickback or bark tearing.

According to the Occupational Safety and Health Administration (OSHA), failure to identify these zones before making a cut is a leading cause of chainsaw-related amputations and fatalities. The correct approach is to make a shallow relief cut (about 1/3 of the diameter) on the compression side first, followed by the primary felling cut on the tension side.

Diagnosing the 'Binding' Problem in Felling and Bucking

The Problem: Kerf Pinch and Bar Trap

Binding occurs when the weight of the tree or log shifts during the cut, closing the kerf and pinching the chainsaw's guide bar. This happens most frequently when bucking logs on uneven ground or felling a tree with a severe back-lean. If the back cut closes on the bar, the saw is immobilized, and the operator is left vulnerable to a falling trunk or rolling log.

The Solution: High-Lift Felling Wedges and Bore Cuts

To prevent binding, you must mechanically hold the kerf open and control the tree's center of gravity. For trees with a back-lean exceeding 5 degrees, standard plastic wedges are insufficient.

• Tool Selection: Deploy 15-inch to 20-inch ABS plastic or magnesium-aluminum felling wedges with aggressive lift ribs. The Oregon 54929 15-Inch Felling Wedge (retailing around $18) features a deep rib design that grips the wood and prevents the wedge from shooting backward when struck.
• Technique: Use a bore cut (plunge cut) to leave a thick column of 'hinge wood' in the center of the trunk. This allows you to cut the back strap of wood and immediately drive the wedge into the kerf without the tree settling onto the bar.
• Striking Tool: Never use the chainsaw's bar to drive a wedge. Use a dedicated 3-pound to 5-pound dead-blow felling mallet or a steel sledgehammer with a non-sparking face to prevent igniting sawdust or damaging the wedge.

Solving Bark Tearing and 'Barber Chair' Splits

The Problem: Vertical Trunk Shearing

A 'barber chair' occurs when a tree splits vertically up the trunk before the felling cut is complete, leaving a dangerous, freestanding column of splintered wood that can snap backward toward the operator. This is highly common in species with brittle wood or high internal tension, such as hickory, ash, and leaning pines. Bark tearing on the stump is a secondary symptom of a dull chain or an improperly sized notch.

The Solution: Chain Geometry and Notch Proportions

Barber-chairing is a failure of cutting speed and notch geometry. If the back cut progresses slower than the tree's forward momentum, the trunk will split.

• Chain Selection: Switch from a standard safety chain to a full-chisel ripping chain for the back cut. The STIHL Rapid Super (RS) 3/8-inch pitch chain cuts significantly faster through the grain than a Picco Micro (PM3) chain, allowing the operator to finish the back cut and retreat before the tree's weight shifts onto the uncut hinge.
• Leave the Strap: When making the back cut, leave a 1-inch to 2-inch uncut 'strap' of wood at the very back of the trunk. This strap acts as a temporary hinge. Once the wedges are driven and the tree begins to tip, the strap snaps cleanly, preventing the vertical split from traveling down the trunk.

Overcoming Overhead Pruning Hazards and Kickback

The Problem: Gravity-Induced Kickback

Using a standard handheld chainsaw above shoulder height drastically reduces operator leverage and increases the risk of the chain catching on the nose of the bar (the kickback zone). When a heavy limb falls, it often pulls the saw downward or twists the bar, leading to loss of control.

The Solution: Telescopic Pole Saws and Bypass Mechanics

Overhead cutting requires specialized reach tools that keep the operator outside the 'drop zone' (a 1.5x radius of the tree's height).

• Heavy Limbs (4 to 8 inches): Use a professional-grade, fixed-length or telescopic pole saw. The Husqvarna 525PT5S (approx. $699) features a 14-inch reach and a specialized harness attachment that transfers the 15-pound weight of the tool to the operator's hips, eliminating arm fatigue and stabilizing the cut.
• Small Limbs (Under 2 inches): Do not use a chainsaw. Use heavy-duty bypass loppers with compound action. The Fiskars 32-inch PowerGear2 loppers multiply cutting force by 3x, allowing clean cuts on live wood without crushing the cambium layer, which invites disease.
• Collar Identification: Always cut just outside the branch collar (the swollen base where the limb meets the trunk). Flush cuts remove the tree's natural chemical defense zone (CODIT), leading to internal rot.

Tool Selection Matrix: Matching the Tool to the Task

Troubleshooting Mechanical Failures Mid-Cut

Even with the correct cutting trees tools, mechanical failures can halt a felling operation. Diagnosing these issues on the spot prevents operators from forcing the equipment and causing irreversible damage.

1. The Chain Bogs Down or Stalls in the Cut

Diagnosis: The depth gauges (rakers) on the chain are too high, preventing the cutter teeth from biting into the wood, or the air filter is choked with fine sawdust.

Solution: Remove the saw from the kerf. Use a flat file and a raker gauge (specific to your chain pitch, e.g., 0.025 inches for a .325 pitch chain) to file down the rakers. Clean the air filter with compressed air—never wash a paper filter with water or solvent.

2. The Chain Throws Off the Bar

Diagnosis: Incorrect chain tension, a worn bar nose sprocket, or cutting with a dull chain that requires excessive downward pressure.

Solution: A properly tensioned chain should snap back against the bar when pulled away from the center, but you should still be able to pull it around the bar by hand (with gloves on). If the bar nose is grooved or the rivets are loose, replace the guide bar immediately. A worn bar will destroy a new chain in under 10 minutes of use.

3. The Saw Cuts in a Curve

Diagnosis: The cutters on one side of the chain are longer than the other, or the bar rails are unevenly worn (common when right-handed operators favor one side).

Solution: Measure the cutter lengths with a caliper. File the longer cutters to match the shorter ones. If the bar rails are uneven, dress them with a flat file or replace the bar. Never force a curved cut; it will bind the bar instantly.