Cutting Tree Barber Chair Risks (5 Pro Arborist Insights)

Investing in Safety: Mastering the Art of Felling Trees and Avoiding the Barber Chair

Felling trees is an investment. It’s an investment in your property, in your firewood supply, and potentially, in your livelihood. But like any investment, it comes with risks. One of the most dangerous and feared risks in tree felling is the dreaded “barber chair.” It’s a catastrophic split that runs vertically up the tree trunk during the felling process, often causing the tree to kick back unexpectedly and with tremendous force. Think of it as the stock market crashing in your face – only with a multi-ton timber instead of numbers.

Over the years, I’ve seen firsthand the devastation a barber chair can cause. I’ve witnessed trees split violently, equipment damaged, and, thankfully not fatally, injuries sustained. I’ve spent countless hours studying felling techniques, analyzing wood properties, and learning from seasoned arborists to understand how to prevent this dangerous phenomenon. In this guide, I’m going to share five pro arborist insights that I’ve found invaluable, insights that can help you fell trees safely and efficiently, minimizing the risk of a barber chair.

Understanding the Barber Chair: A Technical Breakdown

Before we dive into prevention, let’s get technical. A barber chair occurs when the tensile strength of the wood fibers in the tree trunk is exceeded by the forces acting upon it during the cut. These forces include:

• Gravity: The weight of the tree pulling downwards.
• Tension: The stresses within the wood as it bends and sags.
• Compression: The force squeezing the wood fibers together.
• Cutting Forces: The force of the chainsaw as it removes material.

When the tension on the hinge wood becomes too great, the tree splits vertically upwards, resembling the back of an old-fashioned barber chair. This split can happen rapidly and violently, throwing the tree in unpredictable directions.

Data Points and Statistics

• Wood Strength: Tensile strength varies significantly between tree species. Hardwoods like oak and maple generally have higher tensile strength (8,000-15,000 psi) than softwoods like pine and spruce (4,000-8,000 psi). Knowing the species you’re dealing with is crucial.
• Moisture Content: Green wood (freshly cut) is generally more flexible and less prone to splitting than dry wood. However, extreme moisture content can weaken the wood fibers. Ideal moisture content for felling is typically between 30-50%.
• Tree Diameter: The larger the tree diameter, the greater the forces involved and the higher the risk of a barber chair. Trees over 24 inches in diameter require careful planning and execution.
• Industry Standards: OSHA (Occupational Safety and Health Administration) mandates specific felling techniques and safety equipment for professional loggers. While these regulations may not directly apply to hobbyists, they provide valuable guidance.

Arborist Insight #1: Read the Tree Like a Book

The first and most critical step in preventing a barber chair is to thoroughly assess the tree before you even start your saw. I call it “reading the tree.” This isn’t just a casual glance; it’s a detailed inspection that considers several factors:

Identifying Lean and Weight Distribution

• Lean: Determine the tree’s natural lean. Is it leaning significantly in one direction? This will influence where the weight is concentrated and how the tree will fall. Use a plumb bob or clinometer for accurate measurements. A lean of more than 15 degrees can significantly increase the risk.
• Weight Distribution: Examine the crown. Is it heavier on one side? Are there large, heavy limbs extending in a particular direction? Uneven weight distribution can cause the tree to twist or fall unexpectedly.
• Wind: Wind can drastically alter the tree’s lean and weight distribution. Never fell trees in high winds. A sustained wind speed of over 20 mph is generally considered unsafe.

Assessing Tree Health and Defects

• Decay and Rot: Look for signs of decay, rot, or fungal infections. These weaken the wood and make it more prone to splitting. Pay close attention to the base of the tree and any visible wounds or cavities. A good rule of thumb is that if more than 25% of the tree’s diameter is affected by decay, it should be considered unsafe to fell.
• Cracks and Splits: Inspect the trunk for existing cracks or splits. These are weak points that can propagate during the felling process, leading to a barber chair. Pay special attention to cracks running vertically up the trunk.
• Previous Damage: Look for signs of previous damage, such as lightning strikes or broken limbs. These can weaken the wood and create stress points.

Case Study: The Leaning Oak

I once worked on a project involving the removal of a large oak tree that was leaning heavily towards a residential property. A preliminary assessment revealed significant decay at the base of the tree, coupled with a large crack running vertically up the trunk on the side opposite the lean. This combination of factors made the tree extremely unstable and prone to a barber chair.

To mitigate the risk, we used a combination of techniques:

1. Rigging: We used ropes and pulleys to control the direction of the fall and reduce the impact on the ground.
2. Pie Cutting: We used a pie-shaped notch cut to pre-weaken the tree on the side of the lean, encouraging it to fall in the desired direction.
3. Back Cut Wedges: We inserted wedges into the back cut to prevent the tree from settling back on the saw and to help direct the fall.
4. Controlled Felling: We carefully monitored the tree’s movement during the cut and made adjustments as needed to ensure a safe and controlled fall.

By carefully assessing the tree and using appropriate felling techniques, we were able to safely remove the oak tree without incident.

Arborist Insight #2: The Hinge is King: Mastering Notch and Back Cut Techniques

The hinge is the unsung hero of tree felling. It’s the strip of wood that remains uncut between the notch and the back cut, and it plays a crucial role in controlling the direction and speed of the fall. A properly formed hinge will prevent the tree from twisting or kicking back, reducing the risk of a barber chair.

The Open Face Notch: My Go-To Technique

Over the years, I’ve found the open face notch to be the most versatile and reliable technique for controlling tree falls. It involves cutting a notch that opens up at an angle of at least 70 degrees, allowing for a wider range of felling directions and reducing the risk of the tree pinching the saw.

• Step 1: The Top Cut: Make the top cut of the notch at an angle of approximately 45 degrees, angling downwards towards the center of the tree.
• Step 2: The Bottom Cut: Make the bottom cut of the notch at an angle of approximately 25 degrees, angling upwards to meet the top cut.
• Step 3: Remove the Wedge: Remove the wedge of wood created by the notch. Ensure the notch is clean and free of debris.

The Importance of the Hinge

• Hinge Width: The width of the hinge should be approximately 80% of the tree’s diameter. This provides sufficient strength to control the fall while still allowing the tree to hinge properly.
• Hinge Thickness: The thickness of the hinge should be approximately 10% of the tree’s diameter. This provides the necessary flexibility for the tree to hinge without splitting.
• Hinge Alignment: The hinge should be aligned with the desired direction of fall. Any misalignment can cause the tree to twist or fall unexpectedly.

The Back Cut: Completing the Felling Process

The back cut is the final cut that severs the tree from its stump. It should be made slightly above the base of the notch, leaving the hinge intact.

• Step 1: Make the Back Cut: Start the back cut on the side opposite the notch, cutting horizontally towards the hinge.
• Step 2: Insert Wedges: As you make the back cut, insert wedges into the cut to prevent the tree from settling back on the saw and to help direct the fall.
• Step 3: Monitor the Tree: Carefully monitor the tree’s movement as you complete the back cut. Be prepared to move quickly if the tree starts to fall unexpectedly.

Technical Requirements:

1. Notch Angle: 70 degrees or greater for open face notch.
2. Hinge Width: 80% of tree diameter.
3. Hinge Thickness: 10% of tree diameter.
4. Back Cut Height: Slightly above the base of the notch.
5. Wedge Material: High-impact plastic or aluminum.
6. Wedge Size: Appropriate for the size of the tree.
7. Saw Calibration: Chainsaw chain properly sharpened and tensioned.

Arborist Insight #3: Wedges are Your Best Friends: Managing Compression and Direction

Wedges are indispensable tools for preventing barber chairs and controlling the direction of the fall. They work by counteracting compression forces and helping to steer the tree in the desired direction. I’ve seen wedges save the day more times than I can count. They are like the silent guardians of safe felling.

Understanding Compression

Compression occurs when the weight of the tree presses down on the back cut, pinching the saw and potentially causing the tree to split upwards. Wedges prevent this by lifting the tree slightly, relieving the compression and allowing the hinge to function properly.

Types of Wedges

• Plastic Wedges: These are lightweight and durable, ideal for smaller trees and general use.
• Aluminum Wedges: These are stronger than plastic wedges and are suitable for larger trees and more demanding applications.
• Steel Wedges: These are the strongest type of wedge and are used for extremely large trees or when dealing with heavily compressed wood. Avoid using steel wedges with chainsaws as they can damage the chain if contacted.

Using Wedges Effectively

• Placement: Insert wedges into the back cut as you make it, spacing them evenly across the width of the cut.
• Driving: Use a hammer or axe to drive the wedges in firmly, but be careful not to damage them.
• Monitoring: Monitor the tree’s movement as you drive the wedges in. If the tree starts to move unexpectedly, stop driving the wedges and reassess the situation.

Data Points and Statistics:

• Wedge Angle: Wedges typically have an angle of 5-10 degrees.
• Lifting Capacity: The lifting capacity of a wedge depends on its size and material. A typical plastic wedge can lift up to 1 ton, while an aluminum wedge can lift up to 3 tons.
• Optimal Wedge Spacing: Space wedges approximately 6-12 inches apart, depending on the size of the tree.

Case Study: The Back-Leaning Pine

I once encountered a large pine tree that was leaning slightly backwards, making it difficult to control the direction of the fall. The risk of a barber chair was high, as the tree was likely to settle back on the saw and split upwards.

To overcome this challenge, I used a combination of techniques:

1. Multiple Wedges: I inserted multiple wedges into the back cut, spacing them evenly across the width of the cut.
2. Progressive Driving: I drove the wedges in gradually, monitoring the tree’s movement and making adjustments as needed.
3. Leverage: I used a long pry bar to apply additional leverage to the wedges, helping to lift the tree and steer it in the desired direction.

By using these techniques, I was able to safely fell the pine tree without incident, avoiding a barber chair and ensuring a controlled fall.

Arborist Insight #4: Chainsaw Maintenance is Non-Negotiable: Sharp Chain, Sharp Mind

A dull chainsaw is a dangerous chainsaw. A sharp chain is essential for safe and efficient tree felling. It allows you to make clean, precise cuts, reducing the risk of the saw pinching or kicking back. I can’t stress this enough: chainsaw maintenance is not an option; it’s a necessity.

Chain Sharpening

• Frequency: Sharpen your chain regularly, ideally after every tank of fuel or whenever you notice a decrease in cutting performance.
• Technique: Use a chainsaw file to sharpen each cutter to the correct angle and depth. Follow the manufacturer’s recommendations for your specific chain type.
• Consistency: Ensure that all cutters are sharpened evenly to maintain a balanced cutting action.

Chainsaw Maintenance Checklist

• Chain Tension: Check the chain tension before each use. The chain should be snug on the bar but still able to be pulled around by hand.
• Bar Lubrication: Ensure that the bar oil reservoir is full and that the chain is receiving adequate lubrication.
• Air Filter: Clean the air filter regularly to prevent the engine from overheating and losing power.
• Spark Plug: Inspect the spark plug regularly and replace it if necessary.
• Fuel Mixture: Use the correct fuel mixture for your chainsaw (typically 50:1).
• Chain Catcher: Ensure the chain catcher is in good working order. This small piece of plastic can prevent serious injury if the chain breaks.

Technical Requirements:

1. Chain Sharpness: Each cutter should have a sharp, consistent edge.
2. Chain Tension: Chain should be snug on the bar but still able to be pulled around by hand.
3. Bar Lubrication: Bar oil reservoir should be full and chain should be receiving adequate lubrication.
4. Air Filter Cleanliness: Air filter should be clean and free of debris.
5. Spark Plug Condition: Spark plug should be clean and in good working order.
6. Fuel Mixture Ratio: Follow manufacturer’s recommendations for fuel mixture ratio.

Data Points and Statistics:

• Chain Speed: Chain speed typically ranges from 60 to 90 feet per second.
• Sharpening Angle: Sharpening angle varies depending on the chain type, but is typically between 25 and 35 degrees.
• File Size: Use a file size that is appropriate for the chain pitch.
• Bar Oil Viscosity: Use a bar oil viscosity that is appropriate for the ambient temperature.

My Personal Chainsaw Story:

I remember one particularly challenging job where I was felling a series of large pine trees in a remote location. I had been working for several hours, and my chainsaw chain had become dull. I knew I needed to sharpen it, but I was tired and wanted to finish the job quickly. I decided to push through without sharpening the chain.

As I was making a back cut on one of the trees, the dull chain caused the saw to bind and kick back violently. I lost control of the saw and narrowly avoided a serious injury. That experience taught me a valuable lesson about the importance of chainsaw maintenance. From that day forward, I have always made sure to keep my chain sharp and to take the time to properly maintain my chainsaw.

Arborist Insight #5: Personal Protective Equipment (PPE) is Your Shield: Gear Up for Safety

Tree felling is inherently dangerous, and personal protective equipment (PPE) is your first line of defense against injury. I’ve seen too many accidents that could have been prevented with proper PPE. Think of it as investing in your personal safety net.

Essential PPE

• Helmet: A hard hat is essential for protecting your head from falling branches and debris. Choose a helmet that meets ANSI Z89.1 standards.
• Eye Protection: Safety glasses or a face shield are necessary to protect your eyes from flying wood chips and debris.
• Hearing Protection: Earplugs or earmuffs are essential for protecting your hearing from the loud noise of the chainsaw.
• Gloves: Work gloves provide a better grip on the chainsaw and protect your hands from cuts and abrasions.
• Chainsaw Chaps: Chainsaw chaps are designed to protect your legs from chainsaw cuts. They are made of multiple layers of ballistic nylon that will stop the chain and prevent serious injury.
• Steel-Toed Boots: Steel-toed boots protect your feet from falling objects and chainsaw cuts.

Technical Requirements:

1. Helmet Standard: ANSI Z89.1
2. Eye Protection Standard: ANSI Z87.1
3. Hearing Protection NRR: Noise Reduction Rating (NRR) of at least 25 dB.
4. Chainsaw Chaps Material: Multiple layers of ballistic nylon.
5. Boot Standard: ASTM F2413

Data Points and Statistics:

• Head Injuries: Head injuries account for approximately 10% of all logging injuries.
• Eye Injuries: Eye injuries account for approximately 5% of all logging injuries.
• Hearing Loss: Prolonged exposure to chainsaw noise can lead to permanent hearing loss.
• Leg Injuries: Chainsaw chaps can reduce the severity of leg injuries by up to 90%.
• Foot Injuries: Steel-toed boots can prevent serious foot injuries from falling objects and chainsaw cuts.

Practical Example:

I always ensure that my chainsaw chaps fit properly and are in good condition. I check them regularly for tears or damage and replace them if necessary. I also make sure that my steel-toed boots are laced up tightly and provide adequate support.

Conclusion: Knowledge + Preparation = Safe Felling

Preventing a barber chair requires a combination of knowledge, skill, and preparation. By understanding the forces involved, assessing the tree carefully, using proper felling techniques, maintaining your chainsaw, and wearing appropriate PPE, you can significantly reduce the risk of this dangerous phenomenon.

Remember, tree felling is not a race. Take your time, plan your cuts carefully, and never compromise on safety. The investment in safety is an investment in your well-being and your future. So, go out there, fell those trees safely, and enjoy the satisfaction of a job well done.

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