Observational Studies: Strategic, Operational and Budgetary Considerations
Operational Tools and Equipment Considerations · Creating forest sector solutions Operational...
Transcript of Operational Tools and Equipment Considerations · Creating forest sector solutions Operational...
Creating forest sector solutions
www.fpinnovations.ca
Operational Tools and Equipment Considerations
Mark Partington, MSc, RPF, CCEP
Workshop: Forest Harvesting Under Wet Ground Conditions
June 2007
Outline
TOOLS• Ground pressure! Pascal – ground pressure
calculator
• GPS! planning! navigation
• GIS! mapping and prediction
RESOURCES• Best Management Practices! BMP database
• Portable Stream Crossings! PSC database
• Soil disturbance handbook
Introduction
The most important machine consideration in reducing soil disturbance is……….
Ground Pressure - Introduction
• Soil disturbance is greatly dependent on numerous factors, including the ground pressure exerted by a machine
vegetation
soils
weathermachines
Ground pressure – Tire footprint
Ground Pressure - Wheel load and slip
Compaction Compaction and rutting from slip
Ground pressure – Tracks
• Increases the contact area (footprint)
• Can significantly reduce the ground pressure of the machine
Ground pressure - Maintain proper track tension
Ground pressure – Chains
• Increase traction and reduce wheel slip
• Reduces tearing of the forest floor (and soil)
• Does not reduce ground pressure
Ground Pressure – Pascal
• The calculator assists in the estimation of ground pressures exerted by forestry machines with various running gear (i.e., single tires, bogie wheels and tracks)
Ground Pressure - Pascal
• The calculator simplifies ground pressure calculations by automatically providing wheel, traction chain and track data
• To compare the ground pressure with another set of tires, the user simply selects another tire size
Ground Pressure - Pascal
• Comprised of 15 worksheets for various machine configurations
Ground Pressure - Pascal
• The CPPA method is used to calculate ground pressure
• To determine contact area (footprint area), it assumes wheel sinkage at 15% of the wheel radius
• The method is not well-suited for soil compaction estimations R
LB
• To start, go to the “Index” sheet
• Select machine configuration
• A work sheet for selected machine type opens
Ground Pressure - Pascal
• Required machine data for wheeled machines:
! Axle weights and corresponding tire sizes
! Wheelbase, bogie wheelbase and load front guard position in forwarders
! Wheelbase and load suspension point position in skidders
Ground Pressure - Pascal
Ground Pressure - Pascal
Empty machine weight with 30.5L-32 tires: 15 595 kg
Wheelbase: 3.68 m
Load suspension to rear axle: 1.7 m
Load suspension height: 2.4
Load @ 30% skidder weight and 55% on ground: 4600 kg
QUESTION: Ground pressure with 50”(with ring chains) and 70” (no chains) tires
Ground Pressure – Pascal (grapple skidder)
421915 50668x70-32
572711 13268x50-32*
88397 28530.5L-32*
REAR (kPa)
FRONT (kPa)
Footprint Area (cm2)Tire Size
30.5” tires with chains 70” tires with no chains
= 52% reduction in ground pressure
* With ring chains
3.68
4 600
1.7
2.4
Ground Pressure – Pascal (grapple skidder)
17 000 kg load rating
Weight with 650/65-26.5 tires: 19 800 kg
Wheelbase: 5.5 m
Headboard to rear bogie: 2.75
2-tiers of 250-cm logs
Weight with 750/55-26.5 tires and bogie tracks: 24 042 kg
QUESTION: Ground pressure with 650 tires and 750 tires with tracks
Ground Pressure – Pascal (forwarder)
56296232With tracks
1105312661Tires only
REARFRONTREARFRONT
750/55-26.5650/65-26.5
650 tires only 750 tires with tracks
= 56% reduction in ground pressure
2.755.50
17 000
Ground Pressure – Pascal (forwarder)
• FERIC’s ground pressure calculator provides a uniform method of estimating nominal ground pressures exerted by forestry equipment
• Essentially, all forestry equipment is covered
• Simple to use format, especially for determining the effects of different loads and tire sizes
Ground Pressure – Pascal
• GPS devices can be installed in machines to:! Ensure poor practices and sensitive sites were avoided
! Ensure that machine travel within a harvest block was minimized
! Aid the operator in navigating throughout the block
! Provide information on machine movements that can be used in the development of soil protection guidelines
GPS – Planning and Monitoring
GPS – Planning and Monitoring
• FERIC Multidat data recorders
• Ability to record:! machine position! travel speed! date! passes on a trail! operator
GPS – Planning and Monitoring
• Cutover and trail occupation maps can be generated
• Disturbed or damaged areas can be mapped
1.8% 8.0%
GPS – Planning and Monitoring
GPS – Navigation
• Pre-plan trail layout
• Identify sensitive areas
• Identify bunches for the forwarder/skidder operator
GPS – Navigation
• Low-cost marine units now being used
• Buncher operator identifies piles for the forwarder
• Ensures compliance to wood extraction standards
GPS – Navigation
GIS – mapping and prediction
• Perform wetness index analysis function of TAS (identify sinks)
• Overlay terrain analysis outputs with machine movement and rut locations
GIS – mapping and prediction
• Disturbance did not always occur in areas identified as sinks
• Other factors besides sinks determine soil disturbance (machine types, # of machine passes, local weather conditions etc.etc.)
• Dr. Paul Arp’s (UNB) ! depth to water table
GIS – mapping and prediction
• GPS is a useful addition to the management toolbox…
• The first tool still remains the education and skills of field personnel
GPS – Planning and Monitoring
Best Management Practices
• Review of Canadian and US documents (BMPs, guidelines and provincial regulations)
• 266 documents in searchable database
• software on a CD-ROM• updates downloaded at
www.feric.ca
Best Management Practices
• Simple structure for finding documents using keywords, regions, title, author or organization
Best Management Practices
• Description and contact information
• Web links
Portable stream crossing structures
Searchable database of in-woods and on-road options
Portable stream crossing structures
• Simple structure for making searches
Portable stream crossing structures
• Description, photos and contact information for each structure
Portable stream crossing structures
• Relevant reports (pdf) are included
Soil disturbance handbook
• Soil rutting, compaction, erosion and nutrient loss
• Variable terrain conditions and other sensitive site types
• Mechanized full tree and cut-to-length harvesting
Summary
• A change in machine configuration is not going to solve this problem ….
Photo credit: Al Corlett
Summary
• Operator training and advanced planning will go a long way to solving most soil disturbance problems…
Creating forest sector solutions
www.fpinnovations.ca
Mark Partington, M.Sc., R.P.F., CCEP
Workshop: Forest Harvesting Under Wet Ground Conditions
June 2007