Logging Terminology, D to K
Logging Terminology, D to K
Dangling head- A type of harvesting head, usually used on a CTL harvester, with a wrist-like action and attachment to the harvester boom. Also called a "single-grip harvesting head" and can rotate in all three axes.
Deadman- A completely buried anchor, often a log, used where no suitable stumps exist for anchoring.
Deck- A stack of logs, or used as a verb, to stack logs.
Deflection- The vertical distance between the chord and skyline, usually measured at midspan and expressed as a percentage of the span. Also known as "sag".
Delimber- Landing-based piece of equipment used to limb trees brought in unlimbed, usually cut with full tree length harvesters. May be of the stroke delimber type or pull-through delimber model.
Depreciation- The annual reduction in value of a piece of equipment or capital asset due to wear and tear or obsolescence.
Directional
felling- Felling trees according to a predetermined
pattern or lay on the ground. It may involve jacking or pulling of
trees.
Dogs-
Pointed teeth located between the chainsaw bar and motor. Used in
falling or bucking to pivot saw and to maintain position while
cutting.
Dirty chips- Wood chips which include bark and some leaves
or needles, as would be used in a fuel or biomass operation. No
debarker step required before chipping.
Domino Falling- Placing undercuts and backcuts in a series of
trees, then pushing them with another tree. Domino falling is an
unsafe and dangerous practice.
Drawbar- A fixed or hinged tow bar extending out the rear of a tractor.
Drop line- The line from a carriage to which chokers are set.
Drum- A spool around which a cable is wound.
Dump- An area where logs are off-loaded on land or into water.
Dutchman- A flat area produced when two horizontal cuts of the undercut do not meet at a point, thereby leaving a portion of an undercut not removed. An unsafe falling practice.
Efficiency factor- A ratio corresponding to the average percentage of total time that productive work is being performed by personnel or equipment.
Efficiency hour-Identical to "Efficiency factor", but expressed in terms of time, such as a 50 minute hour (I.e.-50 minutes of productive time per 60 minute hour).
Equalizing block- A block used to distribute load as in connecting anchor cables to heel lines in a multiple anchor system.
Escape route- A planned and brushed out route used by fallers to make their way into the clear when the backcut is completed and the tree begins to fall.
Excavator- A hydraulically operated, boom equipped digging machine, most commonly track mounted, which can build full-benched logging roads with little to no sidecast loss.
Export log- A log that meets the species, ring count per inch, diameter, taper, and knot size requirements for export to countries such as Japan.
Extension- A line added to another to increase its length.
External yarding distance (EYD)- The slope distance from the landing to the furthest reachable point within the cutting unit's boundary.
Extra-improved plow steel (EIPS)- A standard grade of wire rope with the highest breaking strength, 15% higher than Improved Plow Steel (IPS) grade.
Eye- A loop at the end of a wire rope secured by splicing or press fitted.
Factor of Safety- The ratio of the breaking strength of a line or material to the applied load.
Fairlead- A device that consists of pulleys or rollers arranged to permit reeling in a cable from any direction; commonly found atop a standing tower yarder.
Fall- See "fell". Note: "fall" and "faller" are often used interchangeably with "fell" and "feller".
Faller- A logger who fells timber; usually restricted to people doing hand felling, not to operators of tree harvesters. AKA "Chopper", "Feller".
Fan-shaped setting- A logging unit with yarding roads radiating from a common landing or common tailhold. Most commonly seen in cable units.
Favorable (grade)- Descending grade in the direction of travel. Opposite of adverse.
Fell-To cut down trees. Also "fall".
Feller-buncher- See "Full-tree length harvester".
Ferrule- A metal sleeve or collar swaged to the end of a wire rope to make a terminal knob.
Fixed-grip harvesting head- The harvesting head type found on feller-bunchers. Usually fixed to the boom or front of the harvester and does not rotate around all three axes.
Fiber core- The central member of a wire rope, made of woven strands of synthetic or natural fibers such as sisal, jute or cotton.
Fire watch- A look-out posted after the logging shift to watch for any fires starting from the day's activities.
Fixed cost- A cost item for a piece of equipment which does not vary in the aggregate or total. In other words, the production or utilization of the equipment does not change the total cost. e.g. interest, insurance, annual depreciation. However, the per unit cost may vary inversly as utilization increases.
Fly- To carry logs completely off of the ground on a skyline.
Flyer- See "shotgun".
FOPS- a) falling object protective structure which protects equipment operators from falling objects, such as trees, limbs, or rocks. When the FOPS also is equipped with windows, or screens to prevent objects from "spearing" the operator, it is secure from foreign-object penetration also. b) FOPS may also stand for fall-over protective structure, similar to ROPS and usually the same structure.
Forwarder- A special vehicle with a cradle or bunk or trailer used to forward logs. Usually it is equipped with its own log loader device and may be tracked or wheeled. Most commonly works with a CTL harvester.
Forwarding- The act of carrying logs off the ground from stump to landing.
Front-end loader- A loader with a bucket or fork hinged to lifting arms which loads or digs entirely at the front end. A common example in the woods is the CAT 966 series of loaders.
Full-tree length harvester- A machine with a fixed-grip harvesting head which can grasp, cut, lift, swing and bunch trees for yarding. Usually this machine does not limb or buck to log lengths as a "cut-to-length" harvester can do. Also know as a "feller buncher".
Gantry tower- The short tower on a modern swing yarder, located just ot the rear of the leaning yarder tower, used to accomodate the walking guy lines and lines to raise and lower the boom of a yarding crane.
Grabinski- A modified highlead yarding system where the butt rigging is attached to a riding block which rolls on the haulback line, providing limited deflection and suspension with a 2-drum yarder. Also nicknamed the "Polish skyline".
Grade resistance(assistance)- The force of gravity resisting (assisting)movement on an adverse (favorable) grade.
Grapple- A hinged set of jaws capable of being opened and closed, used to grip logs during yarding or loading. Can also be attached to swing or nonswinging grapple skidder.
Grapple skidder- A skidder equipped with a grapple to handle logs; used in place of chokers
Grapple yarding- Cable yarding with grapples instead of chokers.
Gravity logging- Any cable system that depends on the force of gravity for the downhill travel of the carriage, I.e.-no haulback line is necessary. See "shotgun".
Ground lead- A method of, or condition in, cable logging in which the pull of the hauling line is parallel to the ground, i.e.-no deflection is provided and hence usually no to little lift.
Ground skidding- Pulling logs parallel to the ground without using an arch to raise the forward end.
Grouser- The raised steel strip the length of a crawler pad to provide traction.
Guy- Lines from a yarding machine to substantial anchors for support against yarding forces.
Guyline- A wire rope used as a guy. Also see "Anchor line".
Gypo- See "busheler".
Hangup- a) A log stuck behind a tree, stump, or other obstruction during yarding, preventing its forward movement. b) To fall a tree so that it lodges in a second tree rather than falling to the ground. c) To get the saw bar caught in the kerf while bucking a log.
Harvesting- A loose term for the removal of trees from the forest, for product utilization.
Harvesting head- A device on CTL and FTL logging machines which automates the harvesting operation and combines several or all steps into this one device, such as felling, limbing, bucking, and bunching.
Haulback block- A block in a cable yarding system used to guide the haulback line. In some systems, may also be called a tailblock.
Haulback line- A wire rope used to pull the mainline with carriage or butt rigging with chokers back to the timber for the next turn.
Hayline or haywire- a) See "strawline". b) Any unsafe or slipshod work procedure.
Hayrack- A type of log hauling trailer with multiple stakes to contain many small trees in the load.
Heel boom- A loader with a grapple or tongs at the end of a boom or arm which forces one end of the log being loaded against the underside of the boom to steady it and raise the front end of the log. Almost exclusively hydraulically operated today (but example of cable-operated heel booms can still be seen in some areas). AKA "hydraulic loader" or a "juicer".
Herringbone felling- Timber felled in a herringbone pattern towards the center of the yarding road.
Highball- Go ahead fast. Do the work at a hurried pace. AKA "balls to the wall".
High climber- A logger who climbs trees to top them or rig them with blocks for cable yarding. Also known simply as a "climber" or "tree climber". Although few, if any, landing spar trees are rigged any more (portable towers having replaced them), there is still a need for climbing trees to rig them for tail spars or to set lines for directional tree pulling during felling.
Highlead- A cable yarding system in which lead blocks are hung on a spar or tower to provide lift to the front end of the logs. Only requires a 2-drum yarder which may provide some limited deflection to the logs. Not a "skyline" cable system.
Highway log truck- A log truck designed to haul a load not exceeding legal highway limits (e.g. weight, width, height, length); parameters will vary by state in the U.S.A.
Hoe chucking- See "Shovel logging"
Hog fuel- Coarse wood chips and bark produced to be burned as fuel. Also known as "biomass chips".
Holding wood- Hinge of wood left uncut between the back of the undercut and the backcut.
Hook- a) n. A curved member used to catch, hold, or pull something. b)v. To attach chokers to logs in the brush.
Hooktender- The working foreman in charge of a yarding crew.
Hoot owl- A logging operation limited to the early morning hours when fire danger later in the day will require a cessation of operations.
Horse Logging- Logging with large draft horses. Very specialized form of logging where the main advantage is low stand impact in selection logging.
Hot deck- A pile of logs from which logs are hauled as soon as they are yarded. AKA "hot loading" or "to hot log".
Improved plow steel- The standard grade of wire rope with a breaking strength 15% less than EIPS. See "Extra improved plow steel".
Independent wire rope core (IWRC)- The central member of a wire rope, consisting of a single small wire rope.
Inhaul- The portion of a cable yarding cycle where a turn of logs is brought to the landing.
Interlock yarder- A yarder which incorporates a means of coupling the main and haulback drums to recirculate the horsepower required to maintain running line tensions.
Intermediate support- A spar tree or cable sling located between the headspar or tower and the tailspar to which a tree jack or "J-bar" is attached to support a multispan skyline.
Jack- a) A mechanical or hydraulic device used to tip over an undercut tree in a desired direction, usually counter to the natural lean of the tree. See "Directional felling". b) A hanger to support a skyline or other line. AKA "J-bar".
Jackpot- A pile of haphazardly felled trees.
Jagger- A broken strand projecting out of a worn wire rope.
Jammer- A light weight, ground lead yarder using tongs and usually mounted on a truck with a spar and boom. Usually relatively inexpensive and equipped with a single drum. It may be used for both yarding and loading.
J-bar- See "Jack" (b).
Jill-poke-A supported straight log, pole, sapling, or bar that strikes an object at an angle, either penetrating the object or pushing it a side. Cat skinners and skidder operators must be especially careful of jill-pokes while skidding. ROPS and FOPS are designed to protect the operator from jill-pokes, among other hazards.
Kerf- The width of a saw's cut.
Kickback- a) When a chainsaw's bar rebounds upward off the log being sawed, often in a uncontrolled manner and out of the faller's control. b) When a tree being felled slips backward off the stump toward the faller.
Kip- A unit of weight or force equal to 1,000 pounds; "thousand (kilo) in pounds".
Knob- See "ferrule"
Knuckleboom- A hydraulically operated loading boom whose mechancial action imitates the human arm. Common on "forwarders".