Chainsaw Manual for Homeowners. Brian J. Ruth
If you do climb in a tree, do not take the chainsaw with you. A corollary to this rule is, do not use a chainsaw to cut over your head or while standing on a ladder.
PERSONAL PROTECTIVE EQUIPMENT
The greatest percentage of injuries is to the left leg and left hand. Chainsaw-proof gloves and leg protection will cut your risk by more than half. Even if you never cut your chaps, they can pay for themselves in the oily dirt and wear-and-tear they will save on your pants. A helmet with visor and faceshield will help protect your face and head from the most disfiguring injuries and gives me a sense of security. Quality steel-toed chainsaw boots can last a lifetime.
The total cost of a safety package ($300–$400) can be more than the chainsaw, but it is cheap insurance: the medical costs of an average chainsaw accident, based on a 2000 study of insurance claims, was $12,000.
■ Hardhat/hearing protection/mesh visor: $50
■ Safety glasses: $5
■ Leg protection: $60
■ Work boots: $100
■ Kevlar-padded work gloves: $25
■ Upper-body protection (optional, but recommended): $100
These protective items dramatically reduce your risk of injury. Would you drive your car without wearing your seatbelt? The same can be said of operating a chainsaw without the proper protective gear.
Have you ever seen a neighbor using a chainsaw in the backyard without chaps, helmet, or foot protection? It would be interesting to know how many emergency room visits were by chainsaw users wearing shorts and tennis shoes.
Personal protective equipment (PPE) is one area homeowners seem to ignore. Even if you follow all of the recommendations for safe cutting, and take every precaution, accidents do happen. Good equipment can protect you.
Brian plans to fell, limb, and buck a large tree with an 18-inch saw. He’s wearing standard protective equipment, plus a chainsaw jacket (sometimes called a forestry jacket) for upper body protection. The orange yoke is reinforced with Kevlar. A jacket like this is hot in summer, but vests offering similar protection are available for about the same price, $100. Compare this to the medical costs of an average chainsaw accident: $12,000, based on a 2000 study of insurance claims.
Controlling the Chainsaw
To learn how to control the chainsaw, consider the forces involved.
■ The chain on the top of the bar races away from the operator.
■ The chain on the bottom of the bar speeds toward the operator.
■ The chain travels downward as it changes direction around the nose of the saw bar.
Remembering high-school physics, for every action there is an equal but opposite reaction. As a result:
■ When you are cutting downward using the chain on the bottom of the guide bar, the forces pull the saw in toward the wood, and/or the wood toward the operator.
■ When you are cutting upward using the chain on the top of the bar, the forces push the wood and the saw engine away from one another.
■ You don’t cut with the nose of the bar. If you did, the forces would tend to rotate the saw upward—that’s kickback.
Controlling the chainsaw requires planting both feet on the ground in a sturdy marching stance and keeping both hands on the saw handles. Whether cutting downward or upward, keeping the saw engine close to the wood helps you control the forces of pull-in and push-back.
As the chain rounds the nose of the guide bar, its motion suddenly acquires a downward component. As a result, when the upper quadrant of the bar nose contacts the wood, it’s liable to be thrown upward. The saw abruptly pivots in your hands in a direction you weren’t braced to resist—that’s kickback as well.
Reading the Tree
Because of gravity, heavy stuff—like trees and tree limbs—tends to fall down. A leaning tree tends to fall in the direction of the lean, and a log lying on a slope tends to roll downhill. Common sense informs you and guides you to be out of the tree’s path.
The energy in living wood is another thing. Wood is supple, and it will bend a long way before it breaks. A limb that is bent under the weight of a fallen tree may pack a tremendous amount of force. The chainsaw operator must learn how to read these forces to predict the behavior of a sprung limb when it’s suddenly cut free. There are three different situations to look out for:
■ Free limb. When you cut into the limb, is it free to fall? Will the falling limb close up on the chainsaw bar, trapping it in the wood? Or will the sawn limb fall easily away? Where will you be—underneath the falling limb, or safely out of the way?
■ Sprung limb. Is the limb trapped and bent (sprung) between the weight of the tree trunk and the ground? When you cut into the limb, is it liable to recoil violently? Which way will it go? Where will you be—in the path of the flying wood, or safely on the other side of the tree trunk?
■ When you remove a limb from a downed tree, what’s left to hold the heavy trunk up off the ground? Is it going to drop straight down, or is it going to pivot unpredictably on the remaining limbs? Where will you be—in the path of the dropping or rolling wood, or safely out of the way?
FREE LIMB
When the tree limb is not sprung and has a clear path to fall to the ground, it’s best to sever it with two cuts. This is true whether the tree is standing or lying on the ground. Make the first cut upward and go a third of the way into the wood. Make the second cut downward, aiming for the first cut. If you were to cut downward in the first place, the limb likely would splinter and fall without being severed. If you were to try and sever it with the upward cut, the limb’s weight likely would trap the saw bar in the cut.
Cut upward...
...cut downward...
... the limb falls to the ground.
TRAPPED LIMB
The bent limbs in this photo are holding the tree trunk up off the ground. If I were to cut into these limbs, they would spring. So I don’t cut them yet. Instead, I remove the unsprung limbs from the top side, then buck the trunk from the small end back toward the butt. When I return to the sprung limbs, there’s not much trunk left. The less weight, the less springing force when you do release the supporting limbs.
Bent limbs support trunk.
Cut the unsprung limbs.
Buck the log.
Kickback