Chainsaws are valuable labor-saving devices used by many farm, ranch, and home owners. However, in the hands of an untrained operator, a chainsaw is extremely dangerous. A chainsaw at full speed runs more than 30 ft. of chain past a single point on the bar in the split-second it takes for a user to react.
Take the following steps to reduce the risk of injury or death when using a chainsaw:
Apply the following recommendations and information regarding PPE whenever you operate a chainsaw:
To learn more about PPE related to operating a chainsaw, view the following video by Progressive Farmer:
There are three size classes of chainsaws. It is important to identify the one that is the best match for the job(s) that you need to complete.
After you have determined the appropriate size chainsaw for your needs, select a chainsaw that is quiet and balanced and equipped with the following safety features:
A chainsaw that is in proper working condition is safer and easier to operate than a poorly maintained machine. Before using your chain saw, take the following actions:
Maintaining proper chain tension during chainsaw operation is important because a loose chain could come off and a tight chain could bind and overheat. When you are sharpening the cutters on the chainsaw chain, wear gloves and cover the chain with a heavy rag. Make sure your chain oiling system is working properly. To learn how to sharpen your chainsaw, watch the following video from Progressive Farmer:
Allow the chainsaw to cool 5 minutes before refueling, and use a funnel or flexible nozzle to avoid spills. Make sure the chainsaw is at least 20 ft. away from any sources of ignition prior to fueling. If any fuel is spilled, wipe the saw dry before starting it. Move the chainsaw at least 10 ft. from the fueling area before attempting to start it.
Always engage the chain brake before attempting to start the chainsaw. There should always be two points of contact with the chainsaw (other than the hand on the starter rope) when starting the chainsaw. Study and practice the two approved starting methods for the gas-powered chainsaws described in your chainsaw operator’s and/or safety manual. Never hold the starter rope and use the weight of the saw to “drop start” the saw—you risk serious injury from recoil of the chainsaw bar. For information about starting a chainsaw, watch the following video from Stihl titled “How to Start a Stihl Chainsaw”:
Maintain secure footing and balance during operation of the chainsaw. Always hold the chainsaw firmly with the right hand on the rear handle and the left hand on the front handle. Use an encircling grip (fingers over/thumb under on each handle). Remember to turn off the chainsaw, engage the chain brake, and carry the saw with the bar facing rearward and the muffler away from you when walking more than 50 ft. or across hazardous terrain. Engage the chain brake when moving short distances (less than 50 ft.) with the chainsaw running.
(Source: University of Missouri with permission granted from Stihl Chainsaw, Inc.)
Violent reaction forces occur when the teeth of a chainsaw catch on something or when wood closes in and pinches the saw chain, causing the saw chain to stop instantly. The resulting reaction forces cause the chainsaw to be pulled away from the operator (pull-in force—frame 1 of image above), cause the chainsaw to be pushed back toward the operator (pushback force—frame 2 of image above), and/or cause kickback toward the operator (kickback force—frame 3 of image above). The pull-in force occurs when the chain on the top of the bar is being used to cut an object. The pushback force occurs when the chain on the bottom of the bar is being used to cut an object. The kickback force occurs when the chain on the upper quadrant of the nose of the bar (frame 4 of image above) comes in contact with another object.
All of these forces happen quicker than the operator can react. Proper PPE; stance (body, foot, and arm position); grip on the chainsaw; and cutting techniques may significantly reduce the occurrence of and risk associated with these reaction forces. Poor control of these reaction forces by the untrained operator, careless operator, or inattentive operator may result in serious or fatal injury.
The kickback force generally is regarded as the most dangerous of the reaction forces because the blade of the chainsaw usually is thrown into the head, neck, or shoulder area of the operator, resulting in serious or fatal injury. The end result of an uncontrolled pull-in or pushback reaction force may be a kickback reaction. If the tip of the chainsaw blade is pulled into another object in the case of a pull-in reaction or strikes solid material as the tip exits the cut at the end of the pushback reaction, a kickback force results.
Take the following precautions to prevent kickback:
Proper felling of a tree with a chainsaw is a planned operational process that results in causing a tree to fall from a standing position to a predetermined location lying on the ground while minimizing risks to the saw operator, coworkers, the residual forest stand, and any other important objects in the immediate area. This complicated process involves hazard analysis, site assessment, and a careful evaluation of the tree’s properties (health, weight distribution, leans, and entanglements with other trees or vines). The results of this analysis are used by the faller (the saw operator) to plan the felling job. The faller sets up escape routes, chooses which specific felling techniques are needed, plans the sequence of events, and selects the tools he or she will need to complete the felling job safely and effectively. The faller communicates the plan to all coworkers and is responsible for the safety of all coworkers and others in the immediate area.
The process of felling a tree with a chainsaw should never be attempted by the untrained chainsaw operator. A faller needs to have had hands-on training in this activity by a skilled professional and supervised practice under the guidance of this skilled professional because of the complicated and inherently dangerous nature of the activity of felling trees.
The following important training and skills-development activities are needed to safely and effectively fell trees:
Limbing is the process of removing the branches and limbs from a fallen tree. Limbing with a chainsaw is perhaps the most dangerous activity the chainsaw operator does in the course of daily chainsaw operation. This is because of the following circumstances:
The process of limbing a fallen tree should never be attempted by an untrained chainsaw operator. A chainsaw operator attempting to limb a tree needs to have had hands-on training in this activity by a skilled professional and supervised practice under the guidance of this skilled professional because of the complicated and inherently dangerous nature of the activity of limbing fallen trees.
(Video Source: Husqvarna.com.)
Bucking is the process of using a chainsaw to cut a tree into lengths of wood usable as pulpwood, saw logs, or firewood. The bucking process usually follows the limbing process but may be combined with the limbing process to help reduce forces on the remaining limbs by removing weight (log length portions) from the previously limbed areas of the tree stem. The hazards associated with this operation are mostly related to sudden movement of the bucked section, the remaining tree stem, or both following or during the bucking cut with the chainsaw. There is a strong possibility that serious or fatal crush injuries may result if an untrained chainsaw operator attempts to buck tree stems. Hands-on training in this activity by a skilled professional and supervised practice under the guidance of this skilled professional will help to minimize the risk of these injuries. The following important training and skills-development activities are needed to buck trees safely and effectively:
(Source: University of Georgia.)
One of the most common problems during bucking is running the chainsaw into the ground. A sawbuck can make this task easier by holding the log still at the appropriate working height so that you can safely cut the tree into the appropriate lengths. Another useful device is a log jack (adapted peavey), which can lift one end of a log off the ground for bucking. Log jacks are commercially available or can be built in a farm shop.
(Video Source: Progressive Farmer Magazine.)
Rains, G. (2013) Chainsaw safety tips. University of Georgia Cooperative Extension. Retrieved from http://www.caes.uga.edu/applications/publications/files/pdf/B%201364_2.PDF.
Stelzer, H. (2011) Selecting and maintaining a chain saw. University of Missouri Extension. Retrieved from http://extension.missouri.edu/explorepdf/agguides/agengin/g01954.pdf
Stelzer, H. (2011) Felling, limbing, and bucking trees. University of Missouri Extension. Retrieved from http://extension.missouri.edu/explorepdf/agguides/agengin/g01958.pdf.
Stelzer, H. (2011) Operating a chain saw safely. University of Missouri Extension. Retrieved from http://extension.missouri.edu/explorepdf/agguides/agengin/g01959.pdf.
Working safely with chain saws. (n.d.) OSHA fact sheet. Occupational Safety and Health Administration (OSHA). Retrieved from http://www.osha.gov/OshDoc/data_Hurricane_Facts/chainsaws.pdf.
Webinar – What You Don’t Know Can Hurt You by L & E Stover Enterprises and hosted by Penn State Forest Resources
Chainsaw safety. (2014). Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from http://www.extension.org/pages/66897/chainsaw-safety.