Logging Safety: A Field Guide

Appendix: Glossary of Logging Terms

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Backcut (Felling Cut):
The last of the three cuts required to fell a tree. Located on the opposite side of the tree from the face. The backcut must never be continued to a point at which no holding wood remains.
Ballistic Nylon:
A nylon fabric of high tensile properties designed to provide protection from lacerations.
The long, thin projection of the chain saw upon which the cutting chain travels; a moving part. Improper use of the blade results in kickbacks and saw cuts.
Base of Tree:
That portion of a natural tree not more than 3 ft. above ground level.
Series of pressures in a felled tree resulting from objects (terrain, stumps, windfalls, etc.) which prevent the tree from lying flat on the ground. The two major components of bind are compression and tension. It is their directional pressures that determine the technique and procedure used while bucking.
Bottom Bind:
One of the five basic tree positions commonly encountered while bucking. A tree in a bottom bind situation is tensioned on the top and compressed on the bottom.
To cut a felled tree into logs.
Process of sawing a felled tree into sections called logs. Length of the log is dependent on the species of the tree and what type of product it will be made into.
Bottom of a felled tree.
Butt Log:
Portion of a felled tree from the butt to the first bucking cut.
Situation created when the two cuts of the undercut (free cut) do not meet exactly, i.e. one bypasses the other.
A block, often wedge shaped, used to prevent an object from moving e.g. a log from rolling, a wheel from turning.
A sling or length of wire rope with attachments, used to encircle the end of a log for yarding.
An employee whose primary job is to fell, buck or limb trees before they are moved to a landing area.
Danger Tree:
A standing tree that presents a hazard to employees due to conditions such as, but not limited to, deterioration or physical damage to the root system, trunk, stem or limbs, and the direction and lean of the tree.
To remove bark from trees or logs.
A stack of trees or logs.
Designated Person:
An employee who has the requisite knowledge, training and experience to perform specific duties.
Escape Route:
A predetermined path of exit used by fellers when felling or bucking. The essential components of an escape route are: selection of the desired direction, distance of the path prior to felling or bucking, and a well-cleared retreat free of obstacles.
Extreme Weather Conditions
  • strong winds in the timber area, where wind velocity reaches sufficient force to blow limbs from standing trees or prevent cutters from felling trees in the desired direction.
  • impaired vision, where conditions such as falling snow, sleet, mist, dense fog, rain, dust or darkness impair visibility to the extent that employees cannot clearly see signals, moving vehicles, equipment and lines, falling trees or other hazards.
  • hazardous snow or ice conditions which prevent escape from hazards such as falling trees, moving logs, vehicles or lighting.
  • electrical storms, extreme cold, fires and mudslides.
To cut down trees.
Falling object protective structure.
Covered, shielded, fenced, enclosed or otherwise protected by means of location, suitable enclosures, covers, casings, shields, troughs, railings, screens, mats, platforms, to prevent injury.
Situation in which a tree is lodged in another and prevented from falling to the ground. This results from a number of causes such as improper face-boring and/or back cutting and the wind. It can be very dangerous.
Hazardous Falling Area:
The area within a circle centered on the tree being felled and having a radius not less than twice the height of that tree.
Humboldt Notch:
One of the three types of notches commonly used to fell a tree (least safe).
Hung/Lodged Tree:
See Hangs
In the Clear:
A position within the work area where the probability of hazardous contact with falling trees, moving logs, root wads, chunks, material, rigging and equipment is minimized by distance from the hazards and/or use of physical barriers, such as stumps, trees, terrain, or other objects providing protection.
A strong thrust of the saw back toward the feller generally resulting from improper use of the nose of the blade or from pinching of the blade in a cut. Kickback causes loss of control of the saw and this in turn results in numerous saw cut injuries each year. Kickback also refers to a tree jumping back over the stump toward the feller. This kind of kickback generally results from a tree being felled into standing timber.
Any place where logs are laid after being yarded and before transport to the work site.
Directional tilt of a tree away from its vertical position. Many times two lean forces may be in play in the same tree. The lean of a tree can be easily established with the use of a plumb bob or axe handle.
Leg Protector:
Ballistic nylon pad attached to one or both pant legs to protect the leg from contact with the saw chain. It can be attached to either the inside or outside of the pant leg.
Limb Lock:
A series of cuts made on limbs to release back or side pressure and create a step in the limb that will prevent the limb from either kicking back and striking the logger or from pinching the saw.
To cut branches off felled trees.
Lodged Tree (Hang):
A tree leaning against another tree or object which prevents it from falling to the ground.
A segment sawed or split from a felled tree.
Logging Machine:
A machine used or intended for use to yard, move or handle logs, trees, chunks, trailers, and related materials or equipment. This includes self-loading log trucks only during the loading and unloading process.
Logging Operations:
Operations associated with felling and moving trees and logs from the stump to the point of delivery, such as the marking of danger trees and trees/logs to be cut to length, felling, limbing, bucking, debarking, chipping, yarding, loading, unloading, storing and transporting of machines, equipment and personnel to, from and between logging sites.
A piece of stationary or mobile equipment having a self-contained power plant that is operated off-road and used for the movement of material. Machines include tractors, skidders, front-end loaders, scrapers, graders, bulldozers, log stackers, log loaders, and mechanical felling devices.
Following the language in OSHA Logging Standard 29CFR 1910.266, "must" is the same as "shall" and is mandatory.
Rated Capacity:
The maximum load a system, vehicle, machine or piece of equipment was designed by the manufacturer to handle.
The ball of a tree root and dirt that is pulled from the ground when a tree is uprooted.
Roll over protection structure.
Serviceable Condition:
A state or ability of a machine, vehicle, tool or other device to operate as it was intended by the the manufacturer to operate.
A machine used to move logs or trees to landing.
The movement of trees or logs by pulling or towing them across the ground from the place they are felled to a landing.
A lateral split of a log, generally a result of improper technique and/or sequence of bucking cuts.
Slope (Grade):
The increase or decrease in altitude over a horizontal distance expressed as a percentage; for example, a change of altitude of 20 feet over a horizontal distance of 100 feet is expressed as a 20% slope or grade.
A dead or dying tree that is still standing or any portion thereof. Snags must be felled prior to beginning work on an area. Special procedures must be observed when felling snags.
Spring Pole:
A tree, segment of a tree, limb, or sapling that is under stress or tension due to the pressure or weight of another object.
Throw Back:
Portions of trees or limbs propelled back toward the timber feller by the action of a tree falling through other standing trees.
Tie Down:
Chain, cable, steel strips or fiber webbing and binders attached to a truck, trailer, or other conveyance as a means to secure loads and to prevent them from shifting or moving when they are being transported.
Tongue and Groove:
Bucking technique used to hold logs in place after bucking cuts are made. Used where trees can slide or roll after bucking.
Top Bind:
One of the five basic tree positions commonly encountered while bucking. A tree in a top bind situation is compressed on top and tensioned on the bottom.
Top Lock:
Limbing technique used to cut off the tops of felled trees whose stem is under stress. Two offset and bypassing cuts are made in the stem near the top of the tree. The first cut is made on the side of the tree that is under compression. The second cut is offset from the first and made on the side of the tree that is under tension.
A car, bus, truck, trailer or semi-trailer owned, leased or rented by the employer that is used for transportation of employees or movement of material.
A section sawn from a tree during the bucking sequence to allow for the directional pressures of various bind situations. Splits, slabs, and excessive wood-pulling are minimized when a wedge is sawn.
Widow Maker:
Any loose overhead debris such as limbs or tree tops that may fall or be thrown from a tree toward the feller at any time. Widow makers are extremely dangerous and present the feller with a continued source of danger.
The winding of cable or rope onto a spool or drum.
The movement of logs from the place they are felled to a landing.