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


• Comprised of 15 worksheets for various machine configurations


• 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


• 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


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


• FERIC Multidat data recorders

• Ability to record:! machine position! travel speed! date! passes on a trail! operator


• Cutover and trail occupation maps can be generated

• Disturbed or damaged areas can be mapped

1.8% 8.0%


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

• 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


• GPS is a useful addition to the management toolbox…

• The first tool still remains the education and skills of field personnel


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


• Simple structure for finding documents using keywords, regions, title, author or organization


• Description and contact information

• Web links

Portable stream crossing structures

Searchable database of in-woods and on-road options


• Simple structure for making searches


• Description, photos and contact information for each structure


• 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

[email protected]

Workshop: Forest Harvesting Under Wet Ground Conditions

June 2007

operational tools and equipment considerations · creating forest sector solutions operational...

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