Czasochłonność zrywki drewna wyciągarkami zagregowanymi z pilarkami spalinowymi w drzewostanach trzebieżowych

The paper presents a time consumption assessment model (EST) of skidding operations using winches aggregated with chainsaws in thinned stands taking into consideration environmental factors, work−day structure elements and harvested timber volume. Differences in time consumption levels were found between early and late thinning operations. The strongest correlation between the EST and the analysed variables was observed for the share of the waiting time for a chainsaw operator to release logs and the category of thinning.