Study of wind fall trees extraction using farm tractor equipped by winch

Short wood extraction with farm tractor equipped with winch is common method of skidding in forest of Astara watershed. Awareness efficiency of such systems helps to forest harveting managers for optimal choice of mechanized harvesting. Therefore, wood skidding with farm tractor was studied in parcel number 2 and 10 of this watershed. Skidding work elements were specified by work study and time of each element was measured by stopwatch. Relation between skidding time as a dependent variable and each of independent variable was surveyed by multivariate linear regression by stepwise method. IUFRO instructions for time study was used for estimating system production also, FRWO instructions for cost estimation. Final result indicated that skidding distance, winching line slope and distance, log number per turn and volume are most effective factors on skidding time of farm tractor. This study revealed that net and gross hourly production was 2.38 and 2.02 cubic meter.