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Primary Transportation “WOODS TURNS” Skidding, Forwarding, Yarding FOR 420 Jan 25, 2002 James Hart. THIS WEEK’S TOPIC - PRIMARY TRANSPORT “TURNS IN THE WOODS”. PRIMARY TRANSPORT. SECONDAY TRANSPORT. “TURN” = ?. LOADING. FELLING MANUAL MACHINE LIMBING TOPPING MEASURING & BUCKING
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Primary Transportation “WOODS TURNS”Skidding, Forwarding, YardingFOR 420Jan 25, 2002James Hart
THIS WEEK’S TOPIC -PRIMARY TRANSPORT“TURNS IN THE WOODS” PRIMARY TRANSPORT SECONDAYTRANSPORT “TURN” = ? LOADING • FELLING • MANUAL • MACHINE • LIMBING • TOPPING • MEASURING & BUCKING • BUNCHING S T O R A G E ROAD TRANSPORT SKIDDING, YARDING, FORWARDING MILL UNLOADING
“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
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
DRAFT ANIMAL SKIDDING • OXEN • HORSES • BIGWHEEL • OR ~35 • Ca ~2 • AL ~50 horses & mules
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
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
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 DISTANCES400-600’ GOOD DISTANCE FOR CRAWLER SKIDDING • HIGHER COST PER TURN, LOAD, $/CCF
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????
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!
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)
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 -
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 SKIDDING COST RELATIONSHIPS
SKIDDING HANG-UPS ROLL METHOD of working around a HANG-UP JUMP METHOD of working around a HANG-UP KICK METHOD of working around a HANG-UP VARIATION OF KICK METHOD of working around a HANG-UP
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 UP TO 60 % SLOPES
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
SKIDDING PATTERNS PARALLEL SUNBURST CLOVERLEAF
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? HIGHER COSTS, LOWER PRODUCTION
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
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
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
SOIL MECHANICS MAXIMUM DENSITY DRY DENSITY • 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 SO WET IT WILL NOT COMPACT TOO DRY TO COMPACT OPTIMUM MOISTURE CONTENT 10 5 15 20 0 SOIL MOISTURE CONTENT % 5 5 5