Original scientific paper
Time Consumption of Skidding in Mature Stands Performed by Winches Powered by Farm Tractor
Janusz M. Sowa
orcid.org/0000-0003-1181-765X
; Agricultural University of Cracow Faculty of Forestry Department of Forest and Wood Utilization Al. 29 Listopada 46 31-425 Kraków POLAND
Grzegorz Szewczyk
; Agricultural University of Cracow Faculty of Forestry Department of Forest and Wood Utilization Al. 29 Listopada 46 31-425 Kraków POLAND
Abstract
The aim of the present research was to determine the characteristics of time consumption in skidding by winch. The research was conducted in pine, fir, spruce and beech mature stands. It covered the operation of skidding from the stand to the skid trail at the distance of up to 50 m. A time study was performed for skidding operations, timber volume and thinning intensity. The average time consumption of skidding in the operational time, assessed in the examined mature stands, amounted to approximately 18 min/m3. Significant differences were observed in frequency levels between early thinnings (24 min/m3) and late ones (13 min/m3). The operational time structure for skidding by winch was characterized by a large share of auxiliary time: 71%. Out of that time, 30% was used for attaching and detaching the load and 36% for the transfer. Approximation was also done of the multiple regression equations. The equations described changes in skidding time consumption, i.e. the Empirical Efficiency Index (EST). The changes depended on environmental factors (stand, cutting category), elements of the working day structure (the share of a given time category in a shift) and task intensity (ratio of the number of harvested trees per area unit). The strongest correlations between the EST and the analyzed variables were observed for the factors related to the percentage of time required for attaching and detaching the load and factors related to operation intensity.
Keywords
work consumption; timber harvesting technologies; skidding; forest utilization
Hrčak ID:
116781
URI
Publication date:
1.10.2013.
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