Yarding pre-bunched stems in thinning operations: Estimates on time consumption

Abstract

Harvesting operations in steep terrain are particularly challenging, especially in environmentally sensitive areas and in very dense forests that are prone to more damage when using mechanized equipment. A possible approach to limit the damage is that of integrating animal and mechanical equipment. A study was carried out to see what operational variables and to what extent are they affecting the time consumption of yarding pre-bunched stems in thinning operations applied to coniferous stands. Following a time and motion study of yarding operations it was found that the extraction distance and lateral yarding distance affected the variation of yarding cycle time. Within a work cycle, load attachment and detachment accounted for almost 65%, the rest being shared by other typical cable yarding functions. The statistics and models presented in this study may be of help in production planning, research and optimization.