Glossary
This glossary is adapted from the S-212 Wildland Fire Chain Saws training program.
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Ax—A part of the faller's safety equipment used for pounding and chopping. It also can be used to plumb the lean of a tree.
Back Cut—The last of the three cuts required to fell a tree. Locate the back cut on the opposite side of the tree from the undercut (face) and at least 2 inches (the stump shot) above the horizontal cut of the undercut (face). The back cut must never be continued to a point at which no holding wood remains.
Barber Chair—A tree that splits vertically when it is being felled. Generally, this is a result of improper facing or back cutting. A portion of the fallen tree is left on the stump.
Bind—A series of pressures in a felled tree resulting from objects (such as terrain or stumps) that prevent the tree from lying flat on the ground. The two major components of bind are compression and tension. Binds determine the technique and procedure used while bucking.
Blowdown—An area of timber blown over by strong winds or storms.
Bole—A tree stem thick enough for saw timber or large poles.
Boring—Using the nose or tip of the guide bar to saw into the tree while felling or bucking.
Bottom Bind—One of the four basic tree positions commonly encountered while bucking. A tree with a bottom bind is tensioned on top and compressed on the bottom.
Brushing—Removing the brush and shrubs while swamping out a work area.
Buck—Sawing through the bole of a tree after it has been felled.
Butt—The base of a tree stem.
Calks—Heavy boots containing numerous steel spikes (calks).
Conventional Undercut—The sloping cut taken from the butt of the tree.
Corners—The holding wood on either outside edge of the tree.
CPR—Cardiopulmonary resuscitation.
Danger Tree—A standing tree that presents a hazard because of conditions such as deterioration or physical damage to the root system, trunk, stem, or limbs, and the direction and lean of the tree.
Dogs (Bumper Spikes)—A chain saw accessory designed for felling and bucking. Chain saw dogs increase the sawyer's efficiency during felling and bucking operations.
Dolmar—Container for holding saw fuel and oil.
DOT—U.S. Department of Transportation.
Double Jack—A long-handled sledge hammer used to drive splitting and lifting wedges.
Dutchman—A portion of the undercut that is not removed. A dutchman generally results when the horizontal and sloping cuts of the undercut do not meet or extend beyond each other. A dutchman is very hazardous because it can change the felling direction.
End Bind—One of the four basic tree positions commonly encountered while bucking. An end bind occurs on steep terrain where the force of gravity closes the bucking cuts.
EPA—U.S. Environmental Protection Agency.
Escape Route—A predetermined path used by fallers when felling or bucking. Determine the direction and distance of the escape route and clear the route before cutting.
First-Aid Kit—A kit including bloodborne pathogen protective equipment (as a minimum, disposable gloves, face masks, eye protection, and CPR clear-mouth barriers) in addition to standard first-aid supplies.
Forest Service Approved—An item that meets Forest Service specifications or conforms to Forest Service drawings.
Guide Bar—The part of the chain saw that the chain travels on. Improper use of the bar (particularly the top and bottom of the bar at the end of the bar's nose) results in kickbacks and saw injuries.
Gunning (Sighting)—Aligning the gunning mark with the desired felling direction. Because the gunning mark is at a 90-degree angle to the bar, the exact position of the undercut can be established easily in relation to the desired felling direction.
Hanging Wedge—A fan-shaped metal wedge.
Hangup—A situation in which a tree is lodged in another tree and does not fall to the ground.
Head Lean—One of the two natural leaning forces found in most trees. Head lean is more pronounced than side lean.
Holding Wood—Section of wood located between the undercut and the back cut. Its purpose is to prevent the tree from permanently slipping from the stump before it has been committed to the undercut. It also helps direct where the tree will fall. The holding wood must never be completely sawed through.
Hinge Wood—Same as holding wood.
Horizontal Undercut—The first of the two cuts required for the undercut. This level cut is at least one-third the diameter of the tree.
Itinerary—Planned route of travel, date of travel, destination, and estimated times of departure and arrival.
Jackstraw—Area where trees have been blown or fallen down in crisscross fashion.
JHA—Job hazard analysis.
Kerf—The slot a saw's cutters make in the wood.
Kickback—A strong thrust of the saw back toward the faller, generally resulting from improper use of the guide bar's nose or from pinching the bar in a cut.
Lay—Refers either to the position in which a felled tree is lying or the intended location of a standing tree after it has been felled.
Lead—The established direction in which all trees in a quarter or strip are to be felled, usually governed by the terrain of the area, its general slope, or the skid road system.
Lean—The tilt of a tree away from its vertical position. Often two leans (such as head lean and side lean) may affect the same tree.
Leaner—A tree that leans heavily.
Limbing—Removing the branches from a felled or standing tree.
MSDS—Material safety data sheet. A compilation of information required under the Occupational Safety and Health Administration's Hazard Communication Standard that outlines the identity of hazardous chemicals; health, physical, and fire hazards; exposure limits; and storage and handling precautions.
NIOSH—National Institute for Occupational Safety and Health.
Offside—The opposite side of the tree from where the faller stands while bucking or felling.
OSHA—U.S. Department of Labor Occupational Safety and Health Administration.
Pie-Shaped Cut—A section sawed from a log during bucking to allow for the directional pressures of various binds. Removing a pie-shaped section of a log minimizes splits and slabs.
PPE—Personal protective equipment and clothing, protective shields, and barriers.
Pistol-Grip Tree—A tree with a curve at the base of the trunk that makes it difficult to identify the tree's lean.
Sapwood—The outer layers of wood in growing trees that contain living cells and reserve material such as starch.
Side Bind—One of the four basic tree positions commonly encountered while bucking. A tree in a side bind is under compression on one side and under tension on the other.
Side Lean—One of the two natural leans found in many trees. Side lean is less pronounced than head lean.
Sitback—Refers to a tree that settles back on the stump, closing the back cut's kerf. Sitback usually occurs because of wind or because the tree's lean has not been determined properly.
Slabbing—A lateral split generally caused by improper technique or by an improper sequence of bucking cuts.
Sloping Cut—The second of the two cuts required to undercut a tree. This cut must be angled to allow a wide opening for the undercut.
Snag—Any standing dead tree.
Sound—Wood that is not rotten.
Spider—A gauge used for setting crosscut saw teeth.
Spike Top—A live tree that has a dead top.
Spring Pole—A limb or sapling that is bent under a tree or other weight.
Stump Shot—Two inches or more difference in the height of the horizontal cut of the undercut (face) and the back cut. The difference in height establishes a step that will prevent a tree from jumping back over the stump toward the faller.
Swamp Out—Clear out brush and other material around the base of trees and the areas where trees will be bucked to provide safe footing and to remove materials that could cause the saw to kick back.
Top Bind—One of the four basic tree positions commonly encountered while bucking. A tree with top bind is under compression on top and under tension on the bottom.
Undercut (Face Cut)—A section of wood sawed and removed from a tree's base. Its removal allows the tree to fall and helps direct where the tree will fall. The face is comprised of two separate cuts, one horizontal, the other sloping. The horizontal cut must be at least one-third the diameter of the tree. The sloping cut must have enough angle to allow a wide opening. The two cuts must not cross each other.
USDA—U.S. Department of Agriculture.
Wedge—A plastic or magnesium tool used by a faller to redistribute a tree's weight in the desired direction and to prevent a tree from falling backward. It also is used while bucking to prevent the guide bar from being pinched.
Widow Maker—A loose limb, top, or piece of bark that may fall on anyone working beneath it.
