Safe working load- The load a wire rope or structure may safely carry. Usually the ultimate or breaking load divided by the desired factor of safety.

Sag- see "deflection".

Sail guy- A guy line attached to end of the leaning tower on a swing yarder. The guy goes slack when the boom swings. AKA "running guy". Largely made obsolete on modern swing yarders by the gantry tower which accomodates the guylines for the yarder.

Salvage value- See "residual value".

Saw log- A log suitable in size and grade for producing sawn lumber.

Scale- To measure the volume of logs, expressed in MBF.

Scale deduction- The volume deducted for rot, breaks, or insufficent trim, from a log's gross scale.

School marm- A forked top tree with two tops.

Self-loading logging truck- A logging truck with its own loading device, generally a knuckleboom mounted behind the cab. AKA "a self loader".

Set- A cutting crew, generally composed of two people, a faller and a bucker. AKA "felling set".

Setback- when a tree settles back on the backcut, opposite the direction in which it was supposed to fall.

Setting- The area yarded or skidded to one landing.

Shackle- A U-shaped metal connector with apin or threaded bolt through the ends. AKA "clevis".

Shay swivle- A fitting used to attach the slack-pulling line to the mainline on a skyline system.

Shear- A mechanical cutting head, attached to a harvester, which severs the tree from the stump with a scissors-like action. Usually an undesirable cutting head for saw timber as it often splits the butt log and degrades the value of that log.

Sheave- A wheel with a groved rim. AKA "pulley".

Singlejacking- When one person does the felling and bucking on a setting.

Shortwood- Pulpwood less than 10 feet long.

Shotgun- A two-drum, live skyline yarding system in which the carriage moves down the skyline by gravity, is lowered to attach logs, then raised and pulled to the landing by the main line. AKA "flyer".

Show- Any unit of operation inthe woods, usually associated with logging, such as a highlead show.

Shovel logging- The use of a hydraulic loader to move and arrange logs into decks in the cutting area or to roads and landings. AKA Hoe Chucking, in Canada.

Side- A logging unit: the workers and equipment needed to yard and load any one unit of operation. e.g. "The company had a cable and skidder side operating in the woods."

Sideblocking- A method of laterally displacing a slackline to facilitate log hookup or permit yarding a wider road. AKA "Dutchman block"

Sidehill yarding- Yarding logs parallel, or nearly so, to the ground contour lines.

Side slope-The average slope of the ground, in percent, along a yarding road on either side of a centerline.

Single-span skyline- A skyline without intermediate supports. Single span skylines are classified as short span if they reach out less than 2000 ft to the tailblock and long span if they exceed 2000 ft. Note, External yarding distances may be shorter than the spar to tailblock distance.

Siwash- A line not running in a straight line by being bent around a tree, stump, rock, etc.

Skid trail- See "cat road"

Skidder- A self-propelled vehicle used to transport logs, generally by dragging them with a grapple or chokers and can be wheeled or tracked.

Skidding- Dragging logs to a landing.

Skidding line- See Slack-pulling line.A line on a slack-pulling carriage that is payed out to hook to chockers. Provides lateral yarding capability and obviates the need to lower the carriage to the ground each time to hook logs.

Skidroad- see "cat road".

Skyline- A cableway stretched tautly between two points and used as a track for a block or carriage.

Skyline carriage- see "carriage".

Skyline corridor- see "cableway".

Skyline logging- A logging method in which a block or carriage rides on a skyline.

Skyline road- See "road"

Skyline profile- The ground profile under a skyline. See profile.

Skyline slope- The slant or inclination of the skyline chord, usually expressed in percent.

Slackline- A live skyline yarding system in which the carriage is pulled to the woods by a haulback line. The skyline is lowered by slackening the line to pemit the chokers to be attached to the carriage, and the turn is brought to the landing by the mainline. Lateral movement is provided by sideblocking. A slackline requires a three drum yarder.

Slack-pulling line- A line used to pull out the main or skidding line through a carriage. (see below).

*Slack-pulling carriage- A carriage capable of pulling in logs (lateral yarding) through the use of a slack-pullingline.

Slash- Debris left on the ground after loggingis complete.

Snap guy- A guyline rigged on the same side of a standing tower yarder as the operating line(s) which prevents the tower from being pulled over backwards by the opposing guys if the operating line(s) break.

Snatch block- A block that can beopened on one side to allow a cable or rope to be laid in the block, instead of threading it through from one end.

Snag- A standing dead tree.

Snorkle- A wooded or steel boom extension mounted on a loader to increase the distance that logs can be reached for loading. A form of logging more common in western Canada than the U.S.

Snub- To lower anything. To assist one machine down a grade by holding it back with another and connected by a "snubbing line".

Snubbing line- A line used in skyline logging to retard a load.

 Span- The horizontal distance between two adjacent skyline supports.

Spar- A tree, wood mast, or metal tower used to support rigging for one of the many cable yarding systems. In the U.S. today, most commonly a mobile, portable tower is the rule.See Tower.

Spot landing- A round or rectangular area cleared for use as a landing.

Spur road- A short, low standard branch road generally accessing one or two landings; often dead ending at the last landing.

Stage-felling- To fell timber in several successive cuts to reduce bole breakage and damage to understory reproduction. AKA "stage cutting".

Stagged pants- Work pants shortened to prevent limbs catching the cuff and tripping the logger. Often left unhemmed and frayed at the bottom..

Standing skyline- A fixed skyline not running during logging operations; for example, a skyline anchored at one or both ends. The skyline length is fixed during yarding and is not raised or lowered during the cycles.Not used very often in today's logging. Preference is given to live skylines or running skylines.

Station- A 100 ft long segment or distance of a road grade or skyline profile.

Strand- A component of wire rope consisting of wires spirally wound together which is then helically laid around the core to form the rope.See wire rope.

Strap- A short cable with an eye in each end. AKA "sling".

Straw drum- A small drum on a yarder holding the straw line.

Straw line- A light cable, usually 3/8 inch or less in diameter, used to string heavier lines. See "haywire".

Strip- The area in which a set of cutters works- a cutting strip.

Stump pull- Splinters of wood pulled from the butt log. If the splinters are too long, stump pull is considered excessive and devalues the butt log.

Stumpage- The value of timber as it stands uncut. The residual value after all logging costs are taken from the delivered price of logs at the mill yard.

Swaged- To press on, such as a ferrule on a choker.

Swamp- To clear brush and obstructions for a cat clearing roads or skidtrails. The person doing this hand work is called a swamper.

Swing- a) To move logs to a landing from a distance deck to which they have previously been yarded.. AKA "shuttle logging". b)The capability of a yarder to swing to either side to position logs beside the machine.

Swing yarder- Any yarder that swings on a turntable, as opposed to a standing spar yarder.

Swivel- a fastening device that allows the parts attached to it to rotate freely.

Tagline- a) A short line added to another line to lengthen it. b) A line used to position a loading grapple. c) See "drop line".

Tailblock- A block at the back end of the yarding area which is used to guide the haulback line and is attached to an anchor or spar tree.

Tailhold- a) The anchorage at outer end of the skyline, away from the landing. b) A line securing a tailblock to a stump.

Tailspar- A spar at the outer end of a skyline system, away from the landing, which elevates and supports one end of the skyline. AKA "back spar".

Tailtree- A standing tree used as tailspar.

Talkie-tooter- A portable radio transmitter, carried by one of the choker setters or rigging slinger on a cable operation, which operates a whistle on the yarder and signals the yarder engineer what cable manuevers to inititiate. Talkie-tooter is a brand name for the most commonly used make of these radio controlled signalers and is often used generically, much like Kleenex or Coke, in woods conversations. AKA a "bug".

Tieback- A line attached to a secondary stump from the main anchor stump to distribute the load on the anchor. Commonly used where one large stump is not available to provide adequate anchorage.

Tightlining- a) In highlead logging, a method of lifting the logs or butt rigging over obstructions by tightening the haulback line with brakes while pulling themainline. b) Moving rigging from one road to another by changing the tailblocks and pulling the cable to the new road by tightening the mainline. [Note: Since highlead logging is usually a use don clear cut units, tightlining can not be done on units where residual trees are to be left standing in the unit.]

Tongs- A pair of curved arms with sharp points, pivoted like scissors to bite into a log for yarding or loading.

Top- To cut off the top of a tree down to a utilizable diameter for use as a spar. (Somewhat rare these days, as mobile, portable spars and towers are the rule.)

Total logging cost- the sum of road and yarding/skidding costs per MBF.

Tower- A steel mast or framework, generally protable, used instead of a spar tree for cable yarding.

a) Standing tower- A vertical, telescoping steel tower, usually cylindrical in cross-section, which is portable and transported fromlanding to landing for cable yarding.

b) Swing tower- A leaning tower, usually of lattice-box steel construction, mounted on a turntable and capable of landing logs to either side as well as in front of the yarder. See "swing yarder".

Tree jack- A J-shaped membe rused for skyline support at intermediate spars.

Trim allowance- The extra length allowed when bucking logs to account for end injury, uneven cut, and trimming of boards in the mill. Trim allowance may vary by local and scaling rule used, as well as by local tradition. In California, for example, this is commonly six inches of trim for a 16 foot or less log and 12 inches for a 32 foot log.

Turn- The logs brought to the landing in any one yarding or skidding cycle.

Twister- A line between anchors used for support by twisitng the line with a sturdy stick to reduce its length.

Ultimate strength- See "breaking strength".

Unclamped carriage- A carriage which holds position without the use of a skyline clamp. See Clamped Carriage.

Undercut- The wedge-shaped first cut made when felling a tree which determines the direction of fall.

Unhook- To remove chokers from logs at the landing.

Unit- See "cutting unit".

Unloaded deflection- Deflection when no logs are being supported on the skyline. See "Catenary curve"

Utility log- A log not meeting the grade requirements of a peeler or saw log, but which will produce at least 50% of its gross volume in pulp chips. AKA chip log.

Variable Cost- The total cost of operating a machine ($/unit) attributable to actual work, such as fuel, track wear, etc.

Wedging- The use of plastic wedges driven into the backcut to direct the tree into its fall and to avoid setbacks on to the chainsaw.

Whistle punk- A somewhat archaic term for the person who controls the whistle (see "Talkie Tooter") on a cable yarding operation. Back in the old days, before radio signals, the whistle punk was a member of the yarding crew who was stationed where he could see the entire operation and could control the whistle signals through the use of a pull line back to the yarder.

Whole tree- Refers to felled trees, unbucked with limbs and tops intact.

Widow maker- A loose limb, top, piec eof bark or anything loose in a tree that may fall on a logger.

Winch- A powered drum used to reel in or pay out cable for yarding or hoisting.

Windfall- See "windthrow".

Windfirm- Tree(s) able to withstand strong winds.

Windrow- Slash, logs, or other material piled in a more or less continuous line to clear the intervening ground.

Windthrow- A tree or group of trees uprooted by the wind. AKA "windfall".

Wire rope-A flexible steel rope made up of numerous wire strands twisted hellically together about a wire or fiber core.

Working strength- the maximum allowable load a wire rope or other material should be stressed to and still maintain the desired "factor of safety". Usually this load is less than the elasticity limit of the wire rope or other material.

Wrapper- See "binder".

Yarder- A machine or system of winches used to haul logs into a landing. Often combined with a portable tower. Technically the yarder is just the power and winch system, but in practicallity today, it is the whole machine including the tower.

Yarder engineer- The person who operates and is responsible for the yarder.

Yarding- The act or process of conveying logs to a landing. In common practice, yarding is often reserved for cable logging, while skidding is used for ground based logging.

Yarding crane- See Swing yarder

Yarding road- See "road".