Chain Saws — Safety, Operation, Tree Felling Techniques

A chain saw is a valuable, labor- reactions they may cause, as well as • face shields or plastic goggles to saving tool for homeowners, forest your surroundings. prevent injuries from wood chips landowners, and professional loggers. Select a chain saw with good safety and sawdust. When used improperly, however, it can features, including features to reduce • ear plugs or muffs to prevent cause serious injuries. Read and follow kickback and an anti-vibration system hearing loss. Chain saw noise is operating manual instructions provided to reduce saw vibration to the user’s greater than the human ear can with the chain saw. hands. This reduces user fatigue and tolerate. Sustained exposure can Good judgment and common sense ensures greater safety. Chain saw cause hearing loss that cannot be are essential to operating a chain operators should know their physical restored. saw safely. Equipment varies, but if a limitations, work slowly, rest often, and • heavy-duty, leather gloves to chain saw manual is not available, the remain alert to potential problems and protect hands from cuts and following guidelines provide important hazards. Saws also should be equipped scrapes. information about chain saw safety, with a continuous pressure throttle • leg protective pants or chaps that operation, and tree felling techniques. control system that shuts off the power cover the upper thigh to boot tops. to the saw’s chain when pressure is Chaps protect against cuts and Safety reduced. can stop the chain before it causes Many safety advancements in Wear comfortable, close-fitting harm if it accidentally contacts the chain saw design have been made, clothing when using a chain saw. Also, user’s leg. but accidents still happen. Chain saw include the following protective equip- • first-aid kit available at the work site. users must observe safety practices. ment (see Figure 1): Before starting the chain saw, check Working safely requires a personal • safety boots with steel toes and the operating manual for the recom- commitment to being constantly nonskid soles. mended fuel mixture, choke setting, aware of your actions and the possible and throttle control. Always start the saw with the chain brake on. Properly Figure 1. Chain saw operator’s safety equipment. adjust the saw so the chain stops when the throttle is released. Start the Hard Hat chain saw at least 10 feet away from Ear Muffs the fueling area. Always fill the oil reservoir when refueling the saw. Face Shield When starting the saw, hold the saw firmly on the ground with your right foot in the rear handle. Grip the front handle with the left hand. Be Safety Boots sure the area under the bar and chain is clear. Check to see that the starter mechanism is engaged, then pull the starter rope sharply with the right hand while keeping a firm hold on the Leg Protection Leather Gloves

Kansas Forest Service 1 starter handle as the rope retracts. Rev Never carry a saw with a moving Breaking chains can cause serious the engine briefly to release the throttle chain. The saw should be shut off or accidents and are nearly always the control latch and let the saw idle. the chain brake engaged when carrying result of a poorly maintained saw. Another method of starting a for distances of greater than 50 feet, Because of the saw’s high speed, the chain saw that should only be used by or when terrain and other physical flying cutters can embed themselves in experienced operators is known as the factors make carrying a running saw the body. There is little risk of breakage “crotch clamp” method. This involves hazardous. in a chain that is properly sharpened, the operator clamping the rear handle Chain saw kickback can cause well lubricated, and correctly adjusted of the saw between his or her legs to serious injuries without giving the for tension. stabilize the saw during the starting operator time to react. When cutting, procedure. Never start a saw on your the chain is traveling about 65 feet per Tree Felling Techniques knee or by drop starting! second. If kickback occurs, it will be 2 Accurate tree felling takes practice to over within /10 of a second. The most master. Because of the hazards involved, Operation common cause of kickback is when the never work alone. When handling the saw, the follow- teeth come in contact with an object as The first step in felling a tree is to ing techniques allow the user to keep they rotate around the tip of the bar. identify all the hazards around the tree, control: This causes the saw to kickback rapidly, such as structures, power lines, roads, • maintain a firm footing with legs backward and upward, toward the vehicles, and other trees. Also look for well apart to support the body. operator (see Figure 2): hazardous, dead branches or rot on the Keep the body away from the saw’s Prevent kickback injuries by: tree being felled. Make sure the area cutting path. Keep the weight of • holding the saw firmly with both is clear of people and animals before the saw close to the body, arms hands. beginning. Check to be sure the chain slightly flexed, allowing the trunk • keeping the thumb around the top saw has enough gas and chain oil to and legs to carry the weight, reliev- handle. finish felling the tree. Work behind and ing the load on the back and arms. • using a saw equipped with a chain slightly to the side of the direction of The hands and arms mainly serve brake or kickback guard. the fall. to guide the saw, bearing as little • watching for twigs that can snag. The second step is to determine the weight as possible. • not pinching the bar. height of the tree and the direction it • when working in a crouched posi- • sawing with the lower part of the should fall. The tree’s high center of tion, avoid back strain by support- bar, not on the top near the nose. gravity causes instability and makes ing the elbows on the knees. • maintaining adequate saw speed its movement difficult to predict and • keep wrists straight to prevent when beginning or completing a control. Other factors to consider in muscle strain in the arms. cut. felling a tree include wind direction and • keep the thumb around the front • selecting chains designed to reduce velocity. Never attempt to fell a tree into handle to prevent the saw from kickback. the wind. Trees that have a definite lean being wrenched from the hands • avoiding situations where the nose should be felled in the direction of the in the event of a kickback. Let the of the bar is likely to encounter a lean, if possible. left hand slide along the handle to fixed object. keep the saw stable and to change Figure 2. Chain saw kickback positions. • do not operate the saw with the power head higher than your shoulders. The safest and least tiring way of sawing is to cut with the backward- running or lower part of the saw bar close to the bumper. Sawing with the forward-running or upper part makes it difficult to control the saw and increases the risk of kickback. Do not overreach while using a chain saw. Overreaching causes loss of grip and chain saw instability. Avoid forcing the saw when cutting. Be alert for wire, nails, and other foreign objects in the wood.

2 Other factors to consider in felling a tree’s center acts as a hinge to control vision and cause kickback injuries. For tree include: the direction of the fall. If the back cut protection, keep the tree trunk between • large branches on one side. goes completely through, the tree may yourself and the branches being cut. If • a crooked trunk or crown trunk swivel on the stump, slide, or bind on the tree is lying on a hillside, however, decay, which can affect the the bar and chain. always limb from the uphill side. Do direction of fall and may be If the tree is larger in diameter than not walk on the tree trunk because it unpredictable. the length of the chain saw bar, cuts on can roll. Maintain footing by clearing • other trees near the one being cut. each side of the tree may be needed. away the cut branches, and be alert for • the slope of the ground in the area. Keep an eye on the top of the tree nails and wire in the wood. Be aware The third step is to plan an escape and the back cut for signs of movement. that removing limbs changes the tree’s route. Ideally, escape routes should be If the tree begins to fall in the intended balance or its support and can cause it to selected at 45-degrees to the rear of the direction, immediately stop the saw, roll to one side. expected fall line. These routes should set it down away from the path of the Cut as close to the trunk as possible. be cleared of any debris or underbrush falling tree, and retreat diagonally away Support the saw against the trunk when that may impede the operator’s from the direction of the fall. Do not using the forward running part of the movement. stand near the tree and watch it fall. A chain. This reduces fatigue and strain. The fourth step is making the notch falling tree can bounce back and strike Run the saw at full throttle as it cuts cut. This cut determines the direction the chain saw operator. into the limb. of the fall and reduces splitting of the If the tree leans back, closing the Pull the saw across the trunk and tree. For trees more than 10 inches in back cut and binding the saw’s cutting support the saw against your right diameter, a notch cut is recommended bar, remove the saw or stop the engine leg. The guide bar will then be in the to help control the direction of the and drive one or two wedges into the correct position for removing the limbs fall. The depth of the notch cut should back cut. Wedges should not touch the on top. be about one-third the diameter of chain or cutting bar. Using full throttle, move the saw the tree, with the wedge cut making Once the tree is felled, look over the forward, using your legs to keep it a 45-degree angle. Make the top cut area and tree carefully to determine how pressed against the trunk. Use the of the notch first at 45 degrees. The the tree will respond when cutting the forward-running part of the chain. bottom cut of the notch should be level trunk into usable log lengths. Tilting the saw will be easier if it is and meet the top cut (See Figure 3). lifted slightly. The final cut is the back cut, or Limbing and Bucking Support the saw against the trunk felling cut. It is made opposite the Limbing is the removal of unwanted and your right leg when limbing the notch cut and should be 1 to 2 inches branches from the trees. Start limbing side next to you. Use the backward- above and parallel to the horizontal cut from the base of the trunk, working running part of the chain. of the notch cut. Never make the back toward the top of the tree. Work slowly When sawing top limbs, move the cut lower than the horizontal cut. Stop and cautiously. Accidents frequently saw forward, using the trunk to support the back cut about 1 to 2 inches before occur during limbing because footing is the saw. Tilt the saw to the right, using cutting through to the undercut notch. poor and obstructing branches impair the thumb to operate the throttle. The holding wood left uncut in the

Figure 3. Proper notch cut.

2"

Top Cut Bottom Cut Back Cut

3 When sawing limbs on the other log and hitting rocks or soil that will until the trunk breaks. Be ready for side, support the saw against the trunk damage the chain. Also, keep an escape kickback. and use the backward running part of route open in case the trunk kicks out. When working on sloping ground, the chain. Move forward only when the Allow the saw to pull into the log stand uphill from the log and see that no guide bar is moving downward on the against the bump spikes when sawing. one is working below the bucking area. other side of the trunk. If the trunk has a downward bend, Preventive maintenance and careful Remove the underneath branches start the cut in the top and then saw use are the best insurance against last, using the forward-running part of from underneath. When the bend is accidents and breakdowns. the chain. For support, rest your right upward reverse the cutting sequence hand against your right knee. Never let (see Figure 4). References the chain saw cut into the ground. Moderate tension in the trunk Loggers’ Safety Training Guide, Forest Bucking is the process of cutting requires a cut through half the trunk Industry Safety & Training the tree into usable lengths. When with the saw upright, then quickly Alliance, Inc., Rhinelander, bucking the tree, be sure to maintain sawing through the remainder of the Wisconsin, 2001. sure footing, hold the saw firmly in trunk. If the trunk is under tension, Felling, Bucking and Limbing Trees, both hands, and stand to one side as the prevent the saw from binding by first Missouri University Extension, cut is started. Care should be taken to cutting a wide notch in the inside of University of Missouri, Columbia avoid cutting all the way through the the bend. Saw a little at a time, slowly, (Pub. no. G-1958) 1998. Logging Professional’s Safety Handbook, Figure 4. Proper bucking techniques. Northern Woods Safety Foundation, Jackman, Maine, 1993. Wildland Fire Chain Saws, S-212, National Wildfire Coordinating Group, Boise, ID 2004 Arborists’ Chain Saw Safety and Equipment Safety Training Guide, Forest Industry Safety and Training Alliance, Rhinelander, WI, 2006

Downward Bend Upward Bend

Eric Ward Kansas Forest Service 2610 Claflin Road Manhattan, Kansas 66502-2798 (785) 532-3300 www.kansasforests.org

• Brand names appearing in this publication are for product identification purposes only. No endorsement is intended, nor is criticism implied of similar products not mentioned. • Publications from Kansas State University are available on the World Wide Web at: www.ksre.ksu.edu This publication is made available in • Publications are reviewed or revised annually by appropriate faculty to reflect current cooperation with the USDA Forest research and practice. Date shown is that of publication or last revision. Contents of this Service. publication may be freely reproduced for educational purposes. All other rights reserved. In each case, credit Eric Ward, Chain Saws — Safety, Operation, Tree Felling Techniques, Kansas State University, April 2011.

Kansas State University Agricultural Experiment Station and Cooperative Extension Service MF-2103 Revised April 2011 K-State Research and Extension is an equal opportunity provider and employer. Issued in furtherance of Cooperative Extension Work, Acts of May 8 and June 30, 1914, as amended. Kansas State University, County Extension Councils, Extension Districts, and United States Department of Agriculture Cooperating, Gary Pierzynski, Interim Director. 4