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Primary Transportation “WOODS TURNS”

Skidding, Forwarding, Yarding

FOR 420Jan 25, 2002

James Hart

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THIS WEEK’S TOPIC - PRIMARY TRANSPORT

“TURNS IN THE WOODS”

PRIMARY TRANSPORT

SECONDAYTRANSPORT

“TURN” = ?LOADING

ROAD TRANSPORT

SKIDDING, YARDING, FORWARDING

• FELLING– MANUAL

– MACHINE

• LIMBING

• TOPPING

• MEASURING & BUCKING

• BUNCHING UNLOADING

MILL

S T O R A G E

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“TURN” WORK ELEMENTS

• RETURN - starts at landing, empty travel on trail, • BUNCHING (ASSEMBLING, ATTACHING) - starts when

equipment leaves road, ends when starts to landing• SKIDDING - starts when loaded equipment is traveling on

recognized skid trail, ends at landing • LANDING (DROPPING, UNLOADING) - arrival, dropping

load, unhooking, piling, sorting, etc• DELAYS (ANYWHERE DURING TURN) -

– UNPRODUCTIVE - no contribution to productivity of system e.g. stuck

– PRODUCTIVE - e.g. required maintenance, trail building

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JAMMER YARDING SCHEMATIC

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KINDS OF PRIMARY TRANSPORT• 1. DRAFT ANIMALS (pre 1900 to present)• 2. CRAWLER TRACTOR SKIDDERS (1900-1960s)

– FIRST MACHINES USED FOR SKIDDING - PNW– DRAWBAR TO ARCHES

• 3. 4-WHEEL TRACTOR SKIDDERS (1900 - present)– FASTER AND FOR SMALLER TIMBER– GRAPPLE REPLACES CHOKER CABLE SKIDDING

• 4. FORWARDERS (1970s - PRESENT)– REPLACING SINGLE AXLE BOBTAIL TRUCKS IN WOODS– REPLACING PALLET SYSTEMS IN THE WOODS

• 5. CABLE SYSTEMS (pre crawler to present)– SEVERAL DIFFERENT SYSTEMS– REPLACED CRAWLERS TO AVOID SOIL DAMAGE

• 6. AERIAL SYSTEMS (relatively recent)– BALLOON - PROVIDES LIFT AND CABLE CONTROLLED– HELICOPTER - FAST AND EXPENSIVE

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DRAFT ANIMAL SKIDDING

• OXEN• HORSES• BIGWHEEL

• OR ~35• Ca ~2• AL ~50 horses & mules

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HORSE SKIDDING OPERATIONS• AN OREGON EXAMPLE:

– 35.5 ac thinning from below in fir-pine, 10-38” DBH, mean 14”, – 3 men, 5 Belgians, log truck with loader – 2277 trees, 80% single log skidding, mostly downslope– largest team of 2 skid was 32” 12’ 6000 lb.– 380’ mean skid distance, 935’ max, avoid 100’ up 10+ % slopes

• ADVANTAGES– less capital investment, easier to move into area– only need 5-6’ space (not 10-12 like machines), leaves higher density– light damage to soil, residual stand and regeneration

• DISADVANTAGES – skidders are ~2.5 X faster, take longer to log an area– cannot log large (>24”) trees, cannot skid > ~100’ up 10% slope– not many horse loggers, cannot work rocky ground

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HORSE SKIDDING COSTS BY SLOPE(Oregon example)

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CRAWLER TRACTOR EQUIPMENT

• HISTORIC 40s to 60s, then faster wheel skidders developed

• WINCHES, CABLES, CHOKERS– advantage when stuck

• DRAWBAR SKIDDINGcan decrease power needs 17 percent by elevating butt of log 5 1/2 feet

• ARCH SKIDDING – detached– integral

• OPERABLE ON SLOPES TO 60%but - erosion and soil damage concern

• 300 FT -TYPICAL SKID DISTANCE• MULTI-PURPOSE MACHINES

very versatile, road construction, skidding

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CRAWLER TRACTOR OPERATIONS

• ADVANTAGES– VERY STABLE– HIGH DRAWBAR PULL– LOW GROUND RESISTANCE– MULTI-PURPOSE e.g. ROAD CONSTRUCTION

• DISADVANTAGES– SLOW 3 mph– LIMITED TO SHORT SKIDDING DISTANCES

400-600’ GOOD DISTANCE FOR CRAWLER SKIDDING

– HIGHER COST PER TURN, LOAD, $/CCF

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WHEEL TRACTOR SKIDDER EQUIPMENT

• DEVELOPED in 60s

faster, more maneuverable,

better on rough trails & in woods

• RUBBER TIRED,

ARTICULATED

• FRONT BLADED

• CABLES replaced by GRAPPLES

• FIXED/STATIC ARCH

• SWINGING BOOM 180deg

• REACHING BOOM (2 cylinders)

• MORE COMPUTERIZED, TRACKED,

LEGGED????

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GRAPPLE

• HINGED SET OF JAWS - OPENED AND CLOSED HYDRAULICALLY

• TYPES: – 180 degree SWINGING BOOM,

– VERTICALLY MOVING, NON-SWINGING BOOM

– RIGID/STATIC BOOM

• ADVANTAGES– LOADING & UNLOADING QUICKER, NO CHOKER SETTER

– SAFER

– LESS SKIDDER MANEUVERING

• DISADVANTAGES– MAY HAVE TO PRE-BUNCH

– HAVE TO DROP LOAD IF STUCK

– BE ADVISED THE HYDRAULIC FLUID GETS HOT AND CAN BURN YOU!

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SWINGING BOOM GRAPPLE

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WHEEL SKIDDING OPERATIONS

• EXAMPLE TIMES FOR WORK ELEMENTS– RETURN 1-5 MINUTES ON SKID TRAILS =f (DISTANCE, SPEED)– BUNCHING 2-45 MINUTES OFF-TRAIL =f (# PIECES, OBSTRUCTIONS)– SKIDDING 2-10 MINUTES ON TRAIL = f (DIST., TERRAIN, OBSTR.) – LANDING 1-3 MINUTES DROPPING, CHOKER REMOVING, PILING– DELAYS 0 MIN. & UP HANGS, STUCK, ROAD BDG, MAINT.– TOTAL 6-63+ MINUTES

• ADVANTAGES– FASTER, BETTER AT BUNCHING TREES/LOGS– 1/4 MILE OPTIMUM SKID DISTANCE, 1/2 COMMON, UP TO 1 MILE

• DISADVANTAGES– CANNOT DROP AND RE-WINCH LOAD WHEN STUCK– MORE ROLLING RESISTANCE– TIRES COSTLY ~$3000 (in mid 70s)

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IMPORTANT FACTORS TO CONSIDER

• STEEP SLOPES- higher road costs, more travel distance

• ROAD DENSITY - more roads ==> less skidding distance

• SKIDDING DISTANCE -

• BRUSH, RESIDUAL TREES -

• OBSTACLES- WET SOIL, DRY SANDS, STONY SOILS -

• THREATENED & ENDANGERED SPECIES -

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POUNDS PULL REQUIRED TO OVERCOME SKIDDING RESISTANCE

POWER FOR 6000 LB LOAD

010002000300040005000600070008000

30%

UPGRADE

10%

UPGRADE

10%

DOWNGRADE

30%

DOWMGRADE

PU

LL

RE

QU

IRE

D (

LB

)

GROUND

ARCH

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SKIDDING COST RELATIONSHIPS

• COST PER CUNIT (100 cubic foot) ARE MINIMIZED AT AN OPTIMUM SKIDDING DISTANCE

• COSTS PER CUNIT (100 cubic feet) INCREASES DRASTICALLY WITH SMALL PIECE SIZE

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WHEEL SKIDDER SYSTEMSDISTANCE v. COSTS SO. PINE 1977

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SKIDDING HANG-UPS

ROLL METHOD of working around a HANG-UP

JUMP METHOD of working around a HANG-UP

VARIATION OF KICK METHOD of working around a HANG-UP

KICK METHOD of working around a HANG-UP

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FORWARDER EQUIPMENT

• WOODS MACHINES, USUALLY RUBBER TIRED, WITH A STAKE BED TO HOLD RELATIVELY SHORT LOGS OR PULPWOOD BOLTS

• USUALLY WITH A KNUCKLE BOOM LOADER

• 2.1 X FASTER THAN A CRAWLER AND DRAY SYSTEM

• REPLACING SINGLE AXLE TRUCKS WITH LOADERS IN THE WOODS

• REPLACING PALLET SYSTEMS IN THE WOODS

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FORWARDER TRANSPORT SYSTEMS• ADVANTAGES

– INSURES FULL PAYLOADS– ALLOWS LONGER SKIDDING/ HAULING DISTANCES (UP TO A MILE)– LESS DAMAGE TO RESIDUAL TREE– SUITED TO THINNING & SMALLER PIECES – NAVIGATE STEEPER TERRAIN THAN SKIDDERS

• DISADVANTAGES– HIGHER CAPITAL, REQUIRE PRE-BUNCHING– LIMITED TO ~ 20 FOOT LENGTHS, OR BOLTS– CANNOT INTEGRATE SAWLOG TIMBER– HIGHER COST PER CUNIT– LESS VERSATILE THAN SKIDDERS– HIGH MAINTENANCE ON LOADER

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SKIDDING PATTERNS

PARALLEL

SUNBURST

CLOVERLEAF

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TRAFFICABILITY & SOIL DAMAGE• POWER REQUIREMENTS

INCREASE FOR EVERY INCH OF SOIL PENETRATION

• HOW ARE SOIL CHARACTERISTICS RELATED TO EQUIPMENT EFFICIENCY AND COST?

• CAN WE USE 20-50 TON HARVESTING MACHINES WITHOUT COMPACTING SOILS?

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AERIAL SOIL DAMAGE

26%

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Critical Path Method (CPM) & Program Evaluation Review Technique

(PERT) Scheduling• THE EXISTENCE OF A LARGE NUMBER OF POSSIBLE

EQUIPMENT AND ACTIVITY COMBINATIONS WITHIN A HARVESTING SYSTEM MEANS PLANNING IS ESSENTIAL

• A LOGGING SYSTEM SHOULD BE DESIGNED SO THAT MEN, MACHINES AND LOGS MOVE TO MAXIMIZE VALUE AND PROFIT

• VARIABLES TO CONSIDER ARE MANY– LABOR SKILLS, CAPITAL INVESTMENTS, ROADS, BRIDGES,– SIZE OF TIMBER, VOLUME PER STEM, LIMBINESS, UNDERBRUSH, – STEMS PER ACRE, VOLUME PER ACRE, – SKIDDING DISTANCE, HAUL DISTANCES, EQUIPMENT SPEED,– TERRAIN CHARACTERISTICS, SOIL, WEATHER, – PRIMARY PRODUCT, – OTHERS

• OPERATIONS ANALYSIS, MANAGEMENT TECHNIQUES

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APPROXIMATE OPTIMUM DISTANCES AND SLOPES FOR LOGGING SYSTEMS

HORSES? 0-10%, 200-400’ >10%, 100’

ENVIRONMENTAL IMPACTS? EROSION / SEDIMENTATION LONG-TERM PRODUCTIVITY LOSS HIGH STREAM TEMPERATURES SPECIES HABITAT LOSS

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VIDEOS TO SHOW • JOHN DEERE CORRIDOR THINNING

VIDEOS– SHOW CHAINSAW CUTTING SYSTEM

• START AT ____ LF FOR ___ MINUTES

– SHOW SKIDDER SYSTEM• START AT ____ LF FOR ___ MINUTES

– SHOW FELLER BUNCHER SYSTEM• START AT ____ LF FOR ___ MINUTES

• JAMMER YARDING VIDEO• START AT ____ LF FOR ___ MINUTES

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SOIL MECHANICS

• CLAYEY SOILS ARE SLIPPERY WHEN WET

• SANDY SOILS HAVE POOR TRACTION WHEN DRY

• LOAMY SOILS ARE MOST TRAFFICABLE WHEN DRY

• LOAMY SOILS COMPACT THE MOST WHEN MOIST

• LOAMY SOILS RUT AND PUDDLE WHEN WET

• COURSE FRAGMENTS ABOVE ~ 35% INCREASE TRAFFICABILITY

SOIL MOISTURE CONTENT %

DRY DENSITY

5

5

55

0 201510

MAXIMUM DENSITY

OPTIMUM MOISTURE CONTENT

TOODRYTOCOMPACT

SO WET ITWILL NOTCOMPACT

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AERIAL HARVEST EFFECTS AT 19 LOCATIONS