Estimating machine rates and production for selected\ud forest harvesting machines operating\ud in the western United States and determining\ud the most economical machine combinations under\ud representative conditions in Turkey

During the last decades, there has been increasing interest in ground-based\ud mechanized harvesting systems in the western United States as harvest of second growth\ud increased. A major reason for that interest is that labor productivity using conventional\ud methods decreases with smaller tree size. In Turkey, the application of mechanization is\ud currently low due to low labor costs and high fuel costs. However, changing economic\ud conditions might increase interest in mechanized harvesting systems in Turkey.\ud To select the most profitable harvesting equipment under given operating\ud conditions, the harvesting manager must know how to determine logging costs to\ud evaluate alternative systems effectively. Analytical methods were used in this project to\ud estimate machine cost and productivity for different harvesting system combinations.\ud Animal logging was also considered because highly mechanized timber harvest\ud systems are expensive, and energy consuming. Animals and farm tractors are the major\ud energy sources for agricultural and forestry work and transportation in Turkey. A small\ud amount of animal skidding also takes a place in forestry operations in the western United\ud States to reduce environmental impact.\ud Forty-two machines were selected from six categories of ground-based forest\ud harvesting machines, including skidder, forwarder, harvester, feller-buncher, loader, and\ud crawler tractor. Machine rates were estimated for selected forest harvesting machines\ud under representative conditions in both western United States and in Turkey. Cable\ud harvesting systems are described but not analyzed. A microcomputer spreadsheet\ud program was developed to calculate machine rates.\ud Harvesting operations from stump to truck were investigated to have a clear\ud picture of harvesting operations including fellling and bucking, skidding, forwarding,\ud yarding, and loading. Harvesting production and harvesting costs were determined\ud depending on the types of equipment being operated. To estimate production rates for\ud specific logging equipment, cycle time was obtained from the production equations as a\ud dependent variable, and converted to production using log size, volume, or weight.\ud Production equations are based on studies that have provided useful data to investigate\ud productivity of the logging equipment under various harvesting conditions.\ud Finally, the most economical machine combination, which minimizes the unit cost\ud of logging, was investigated for three different regions of Turkey. The data including\ud topographic data, road data, tree and log data, soil data, and cost data was collected from\ud selected sample plots of each region as representative conditions. In the sample plots\ud selected from Black Sea and Aegean regions, the cut-to-length system using four sawyers\ud and a forwarder produced wood on the truck at the lowest cost, $11.18/rn3, and\ud $13. 88/m3, respectively. In the sarnple plots selected from Mediterranean region, the\ud whole-tree systern using four sawyers, a grapple skidder, and a loader produced wood at\ud the lowest cost ($9.20/m3). This compared to an estirnated logging cost of about $7.00/m3\ud to $10.00/rn3 in Turkey using chain saw felling, oxen skidding and rnanual loadin