Original scientific paper
Estimation of Trafficable Grades from Traction Performance of a Forwarder
Jörg Hittenbeck
; Department of Forest Work Science and Engineering Faculty of Forest Science and Forest Ecology Georg-August-University Göttingen Büsgenweg 4 Göttingen GERMANY
Abstract
Wood as a renewable resource is getting more and more popular for material use as well as for energy usage. In order to meet the demands, it is important to make previously unused wood potentials accessible to the timber market. One area of interest is the incompletely utilized resources in inclined regions. Problems arise in these areas by the topographic limitations of highly mechanized timber harvesting. These limitations occur from the stability of the machine as well as from the damages done to the soils.
Considerations about the downhill slope forces acting on the machines show a direct relation between the inclination of a grade and the traction coefficient. In theory, it seems possible to calculate a trafficable grade for an accepted level of wheel slip. On the basis of a 25% slip limitation, a model for trafficable grades was developed and tested for typical hillside conditions.
Measurements of traction force vs. slip identified the soil water content and the skeletal rate as the main soil parameters that affect the climbing ability of machines. Test drives in inclined terrain indicated that the approach of calculating limitations (for trafficable grades) from traction tests under level conditions lead to a fairly good prediction.
Keywords
full mechanized harvesting; slope; loess; slip resistance; model
Hrčak ID:
116730
URI
Publication date:
3.6.2013.
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