Time study and skidding capacity of the wheeled skidder Timberjack 450C in Caspian forests

This study was carried out in a steep and difficult terrain. Trees were logged downhill to the landing by a wheeled skidder Timberjack 450C. Selection cutting was performed on a 66-hectare tract with an average slope of 30%. The elemental time study method was applied to develop the skidding time predicting model. In this study 43 working cycles were included. The skidding cycle time was mainly affected by skidding distance, winching distance and interaction between skidding distance and slope. The gross and net production rate was 20.51 and 22.93 m3/h, respectively. The unit cost considering the gross and net production rate was 6.31 and 6.22 USD/m3, respectively.