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INTRODUCTIONCABLE YARDING OPERATIONSHIGHLEAD, LIVE SKYLINE, RUNNING SKYLINEDEMONSTRATION/CONTEST

FOR 420Feb 1, 2001

James Hart

Cable Logging, Equipment & Systems

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CABLE YARDING• CABLE YARDING - MOVEMENT OF LOGS FROM

STUMP SITE TO LANDING USING A MACHINE

EQUIPPED WITH MULTIPLE DRUMS (OR

WINCHES) OPERATED FROM STATIONALRY

POSITIONS IN THE LANDINGS.

• FIRST STEAM DONKEY (SMALL YARDER WITH A

VERTICAL BOILER) WAS INVENTED ~1881 BY

JOHN DOLBEER TO GROUND SKID LOGS IN

OREGON

• FIRST SKYLINE CABLE SYSTEM USED IN

MICHIGAN ~ 1886 BY HORACE BUTTLER.

• SYSTEMS STILL IN USE

OLD PNW YARDER

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BASIC CABLE YARDING SYSTEM COMPONENTS

• YARDER - TYPICALLY A RECTANGULAR FRAME BUILT FROM I BEAMS, WITH ENGINE AND DRUMS

• TOWER, WITH GUY LINES

• WIRE ROPE 6 STRANDS OF 19 WIRES EACH– MAIN LINE 1-1.25” -- HAULBACK LINE 3/4-7/8”

– SKYLINE 1.5-2” -- OTHER MISC.

• BLOCKS - PULLEYS

• CKOKER - SHORT FLEXIBLE WIRE ROPE

• BUTT RIGGING - COMBINATION OF CHAINLINKS, CLEVISES, AND SWIVELS CONNECTING

– MAIN HAUL LINE

– CHOKER OR GRAPPLE, AND

– HAUL-BACK LINES

• CARRAGE - COMBINATION OF PULLEYS, CABLE, ETC. THAT RIDE ON SKYLINE, ARE PULLED BY MAINLINE AND MAYBE A HAUL-BACK LINE, HAVE CHOKERS OR A GRAPPLE; AND PERHAPS A SLACKLINE

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HIGHLEAD SYSTEM

• CLEARCUTS

• CONSTANT SLOPES

• 30-70% SLOPES, 1000’

DISTANCES

• UPHILL YARDING

• 2 DRUM YARDERS

• DRUM -- MAINLINE --

BUTT RIGGING (with

CHOKERS/GRAPPLE) --

HAUL-BACK LINE (with

BLOCKS) -- DRUM

• 20 LOGS/DAY

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HIGHLEAD SYSTEM [CONT]

SKAGIT 3-DRUM PORTABLE TOWERWITH GUY LINES

CABLE LOGGED CORRIDOR IN PNW

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LIVE SKYLINE SYSTEM• SKYLINE LIFTS LOGS • LIVE SKYLINE MOVES

UP/DOWN TO GET CARRAGE TO LOGS

• 2-DRUM YARDER IS ELEVATED, USES GRAVITY AND NO HAUL-BACK LINE

• 30-90% SLOPES, 500-4000’ • DRUM -- SKYLINE --ANCHOR

(or TAIL-SPAR TOWER)• DRUM -- MAINLINE --

CARRAGE (with CHOKERS OR GRAPPLE)

• ELEVATED OPERATION– ALLOWS PARTIAL CUTS – DECREASES DISTURBANCE

• 470 LOGS/DAY

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RUNNING SKYLINE SYSTEM• 3rd DRUM FOR HAULBACK

LINE • DRUM -- SKYLINE --ANCHOR (or

TAIL-SPAR TOWER)

• DRUM -- MAINLINE -- CARRAGE (with CHOKERS OR GRAPPLE) - HAUL-BACK - DRUM

• ELEVATED SKYLINE– ALLOWS PARTIAL CUTS

– DECREASES DISTURBANCE

• UPHILL OPERATION

• 4th-DRUM CAN ADD SLACK-PULLER TO LOWER/RAISE CABLE AND KEEP SKYLINE STATIC

• 30-90% SLOPES, 500-4000’

SLACK-PULLER CARRAGE

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CABLE LOGGING SYSTEMS------------------------------------------ ADVANTAGES DISADVANTAGES• can yard logs over ground

on which tractors cannot operate

• Running skylines operate in any direction– up-slope– down-slope

• operate in any weather• less damaging to soil than

tractor skidding• operates faster than tractor

on same terrain

• limited primarily by the line capacities of the yarder drums

• the high-lead is used for only clear-cut

• the cost of moving, and changing yarding road are fixed, not efficient for low volumes of harvesting

• High costs per unit for low values per acre discriminates against small log operations

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OPTIMUM DISTANCES AND SLOPES FOR LOGGING SYSTEMS

HORSES?0-10%, 200-400’>10%, 100’

ENVIRONMENTAL IMPACTS?EROSION / SEDIMENTATIONLONG-TERM PRODUCTIVITY LOSSHIGH STREAM TEMPERATURESSPECIES HABITAT LOSS