engleski

Resistance coefficients on ground-based winching of timber

This paper deals with the research of resistance differences in winching of logs with their thicker or thinner end turned forward. Winching represents traction of wood assortments on the ground from the felling site to the forest vehicle equipped with a forest winch. The winching coefficient is determined by the horizontal tractive force and weight of the traction load. The research of resistance in winching wood assortments was carried out for the purpose of determining the size of the forest winch designed for equipping the prototype of the thinning tractor assembly (adapted farming tractor, forest semi-trailer and hydraulic crane) and developing an environmentally and economically viable technology for timber production. The research was carried out on flat forestland in a pedunculate oak stand by winching three logs of different weight. The research results have shown that the winching coefficients depend on the weight of logs, shape of log and their direction. Higher weight causes higher traction resistance. In all cases, the winching coefficients were higher in winching of logs with their thicker end turned forward. In order to achieve lower ground-based traction resistance and, at the same time, cause less damage to forest soil, winching of logs should be carried out with their thinner end turned forward.

winching coefficient; traction; tractor assembly; thinnings; weight of log

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