1 primary transportation “woods turns” skidding, forwarding, yarding for 420 jan 25, 2002 james...
TRANSCRIPT
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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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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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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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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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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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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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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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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