The methods to safely start and operate a saw can vary with the make and model.
Take extra care when starting your chain saw. Because you won’t have both hands on the saw, you will need to be more careful to maintain complete control. Remember that on/off switches may vary with different makes of saws.
• Ensure that appropriate PPE is available and is worn correctly.
• Maintain a secure grip on the saw at all times.
• Always start the saw with the chain brake engaged.
• Start the saw on the ground or where it is supported ﬁ rmly with the nose of the saw bar over a stump or log. To successfully start a cold saw, “feather” the throttle trigger. Avoid engaging the throttle lock or the fast idle position of the on/off switch.
• Make sure that the saw’s bar and chain do not contact anything.
A full-wrap handlebar allows cutting from both sides of the tree using the bottom of the bar, the part of the bar that can be used aggressively. In some situations the ability to cut wood rapidly is critically important for safety. Full-wrap handlebars are designed to be used by both the left and the right hand. The sawyer’s thumb should always be wrapped completely around the handlebar, no matter how the saw is turned. The thumb and ﬁ ngers are essential for maintaining control of the chain saw, especially during a kickback. The grip on the chain saw should be ﬁ rm, but not overly tight.
• Never operate a chain saw with one hand. You do not have control of the saw and increase the risk that you will be injured if the saw kicks back.
• Always grip the saw ﬁ rmly with both hands.
• Grasp the throttle handle ﬁ rmly with your dominant hand and grasp the handlebar with your less dominant hand. Your ﬁ ngers must encircle the handlebar with the thumb wrapped underneath.
• Never operate a chain saw with the throttle lock engaged. If you do, you will not be able to control the saw or the chain speed.
• Make sure your work area is clear of people and obstacles, such as rocks, stumps, holes, or roots that may cause you to stumble or fall.
• Make sure that the saw chain does not contact any materials such as rocks or wire. Such contact is a safety hazard and will dull the chain. The chain will require ﬁ ling or it may be damaged in ways that ﬁ ling cannot correct.
• Cutting with the bottom of the bar pulls the chain saw away from the sawyer. Cutting with the top of the bar pushes the saw back at the sawyer. Cutting with the bottom of the bar increases efﬁ ciency and decreases the sawyer’s fatigue.
The laws of physics explain that for every action there is an equal and opposite reaction. These reactions happen very quickly during chain saw operation and can be dangerous
Kickback—Kickback is the most powerful reactive force you will encounter while operating a chain saw. Kickback can occur while felling, limbing, bucking, or brushing when the upper quadrant of the bar nose contacts a solid object or is pinched
During kickback, the bar is forced up and back in an uncontrolled arc toward the sawyer. Many factors determine the severity of the kickback and the arc, including: chain speed, angle of contact, condition of the chain, and the speed at which the bar contacts the object.
Ways to avoid kickback:
• Hold the saw with both hands, securely gripping the handle and the handlebar between your thumb and foreﬁ nger.
• Be aware of the location of the bar’s nose at all times.
• Never let the bar’s nose contact another object.
• Never cut with the power head higher than your shoulder.
• Never overreach.
• Pull the saw smoothly out of the cuts. This technique will help to reduce kickbacks and fatigue.
• Cut one log at a time.
• Stand to the side of the kickback arc.
• Use caution when entering a partially completed cut.
• Use a properly sharpened and tensioned chain at all times.
• Watch the cut and the log for any movement that may pinch the chain.
• Use a low kickback chain.
Pushback—Pushback occurs when the chain on the top of the bar is suddenly stopped by contacting another object or by being pinched. The chain drives the saw straight back toward the sawyer.
Ways to avoid pushback:
• Only cut with the top of the bar when necessary.
• Watch the cut and the log for any movement that may pinch the top of the bar
• Do not twist the bar when removing it from a boring cut or underbuck
Pull-In—Pull-in occurs when the chain on the bottom of the bar is caught or pinched, and suddenly stops. The chain pulls the saw forward
Ways to avoid pull-in:
• Always start a cut with the chain at or near full speed and with the bumper spikes (dogs) contacting the wood.
• Watch the cut and the log for any movement that may pinch the bar. Use wedges to keep the cut open.
Axes—Axes are used to remove bark from trees and to drive wedges during felling and bucking. The ax handle should be smooth and free of cracks. The head should be securely attached to the handle. Axes used for driving wedges should have a straight handle.
Single-bit axes need to be heavy enough (3 to 5 pounds) to drive plastic wedges into the trees being felled. The back of the ax (poll) should be smooth, have rounded edges, and be free of burrs to minimize damage to wedges. Pulaskis should never be used to drive wedges.
Always remove branches, underbrush, overhead obstructions, or debris that might interfere with limbing and chopping. Do not allow anyone to stand in the immediate area. Make sure workers know how far materials may ﬂ y. Protect all workers against ﬂ ying chips and other chopping hazards by requiring them to wear the appropriate PPE.
Always position your body securely while working with a tool. Never chop crosshanded; always use a natural striking action. Be alert when working on hillsides or uneven ground. If you cut a sapling that is held down by a fallen log, the sapling may spring back. Be alert for sudden breakage. If you do not need to cut something, leave it alone.
Never use chopping tools as wedges or mauls. Do not allow two persons to chop or drive wedges together on the same tree. When chopping limbs from a felled tree, stand on the opposite side of the log from the limb being chopped and swing toward the top of the tree or branch. Do not allow the tool handle to drop below a plane that is parallel with the ground unless you are chopping on the side of a tree opposite your body.
If the cutting edge picks up a wood chip, stop. Remove the chip before continuing. To prevent blows from glancing, keep the striking angle of the tool head perpendicular to the tree trunk.
Wedges—Wedges are essential tools for safe felling and bucking. They provide a way to lift the tree, preventing the tree from sitting back when it is being felled. A wedge must be inserted into the back cut as soon as possible. Wedges also reduce binds on the saw when bucking logs.
Select the correct wedge for the job. The proper type, size, and length or a wedge varies, depending on its use. The size of the tree being felled or the material being bucked determines the size of the wedge that will be needed. If the wedge is too small, it may be ineffective. If the wedge is too long, it may not be able to do its job without being driven so far into the tree that it contacts the chain.
Always drive wedges by striking them squarely on the head. Drive them carefully to prevent them from ﬂ ying out of the cut.
Check wedges daily or before each job. Do not use cracked or ﬂ awed wedges. Wedges that are damaged need to be cleaned up before they are used again.
Grind wedges to the manufacturer’s original shape and angle. Wear eye protection and a dust mask.
Repair any driving tool or remove it from service when its head begins to chip or mushroom.
Carry wedges in an appropriate belt or other container, not in the pockets of clothing.
Most wedges are made out of plastic or soft metal, such as magnesium, and come in different sizes. Use plastic wedges in both felling and bucking operations to prevent the saw chain from being damaged if it contacts the wedges.
The two basic types of wedges used in sawing are single and double taper.
Single-taper wedges (ﬁ gure 3–21) are simple inclined planes designed to provide lift during tree felling. As the wedge is driven into the back cut, the tree hinges on the holding wood, redistributing the tree’s weight. The sawyer must coordinate striking the wedge with the forward sway of the tree, allowing the wedge to be driven more easily and sending less of a shock wave up the tree. Striking the wedge when the tree is in its backward sway sends a severe shock wave up the tree and can knock out dead branches or tops, endangering the sawyer. Sawyers should look up for falling material after each blow to the wedge.
Double-taper wedges (ﬁ gure 3–22) are designed to reduce bind. They taper equally on both sides from the centerline, forcing the wood to move equally in both directions. They perform best when used in bucking to prevent the kerf from closing, which would cause the guide bar to bind.
Fuel and Oil Containers—Use Forest Service-approved containers to transport fuel and oil. All lids shall be fully sealed prior to transport.
• Even empty containers are dangerous.
• If a container is missing a lid or showing signs of a defect such as cracks, take it out of service immediately.
• All employees who handle, transport, or use ﬂ ammable or combustible liquids shall receive hazard communication standards training and be familiar with material safety data sheets.
• Passengers shall not ride in the enclosed cargo portion of a vehicle hauling ﬂ ammable or combustible liquids. If it is absolutely necessary to carry ﬂ ammable or combustible liquids with a passenger vehicle, a minimum amount of such cargo shall be secured in a rack on the roof.
• Never transport fuel in the same cargo area with oxidizers, acids, or radio equipment.
• Flammable or combustible liquids shall be carried in Forest Service-approved containers. Such containers shall be clearly labeled to identify the contents.
Containers shall never be ﬁ lled more than 90 percent with fuel. Fuel vapors need room to expand. A chain saw should be fueled only after the saw has cooled completely.
Fueling a Chain Saw
• Allow the saw to cool for at least 5 minutes before refueling.
• Fill the saw on bare ground or other noncombustible surface.
• Immediately clean up spilled fuel.
• Refuel outdoors and at least 20 feet from any open ﬂ ame or other sources of ignition.
• Do not start the saw closer than 10 feet from the fueling area.
Peaveys and Cant Hooks—The blacksmith Joseph Peavey invented the peavey (ﬁ gure 3–23a). Both the peavey and the cant hook (ﬁ gure 3–23b) use a curved metal hook on the end of a straight handle to roll or skid logs. A peavey has a sharp pointed spike at the lower end, while a cant hook has a tow or lip. Most peaveys and cant hooks come with a duckbill hook that is a good all-around style. Peaveys and cant hooks come with hickory handles that are from 2 to 5½ feet long.
Peaveys are used almost exclusively in the woods. Peaveys are handy for prying logs up onto blocks to keep the saw from pinching while bucking. The cant hook is used primarily to roll logs.
• Keep the handle free of splinters, splits, and cracks.
• Keep the point sharp.
• Keep your body balanced when pushing or pulling the pole.
• Grip the handle ﬁ rmly. Do not overstress it.
• Carry the peavey with the point forward, grasping it just behind the point of attachment of the hook. Secure the hook to the shaft to prevent it from swinging free.
• Place a guard on the point when the tool is not in use.