Time and motion analysis on cable skidding with agricultural tractors of coniferous logs

The precise calculation of the unit cost of the timber logs depends on the accuracy of unit working time in harvesting operation. Currently, the unit working time is determined by using derived coefficients depending on some variables obtained through previous time studies. This study was conducted to estimate unit time of cable skidding with agricultural tractor as one of the timber extraction methods. In this research, by taking various variables into account, time study analysis was performed on extraction of wood-raw materials obtained from Turkish red pine, black pine, fir and Scots pine tree species by using a cable attached to the tractor. The data were obtained from the programmed harvesting sites of Adana, Bolu and Kastamonu Forest Regional Directorates by implementing direct time measurement method. As a result of the research, in the extraction of logs from the harvesting units by cable skidding, human working time and machine working time per cubic meter were calculated separately on the basis of tree types by considering the variables including the number of pieces, cable length, slope of the road, and the amount of load. Besides, it was determined that average human and machine working time was respectively 21,26 and 17,60 min/100 per cubic meter under the conditions of 100 m skidding distance, 50 percent slope gradient, and 5 pieces at each shift in cable skidding for coniferous logs