Productivity analysis of portable winch system used in logging operations after storm damage

The storm damages that negatively affect forest resources result in serious losses in many regions. Storm damages are generally encountered as tree breaks and tree overturns. Extraction of storm damaged trees after storm damage requires series of very difficult and risky activities. In order to continue regular forestry activities and prevent potential insect and fungi impacts on damaged trees, it is aimed to extract salvage timber from forests at the shortest time possible. Thus, mechanized harvesting methods which are high productive and advantageous in terms of work safety should be utilized. In Turkey, skidding with farm tractor is widely used in mechanized harvesting activities. However, timber extractions are also performed by using portable winches with cable in the cases where farm tractors are not suitable due to economical or ecological factors. In the application, forest products are skidded on the ground by portable winch integrated with skidding cone. By using skidding cones, the skidded logs are not stopped by residual trees, stumps, and other obstacles in the field which leads to increased productivity due to reduction in delay time. In this study, productivity of portable winch was evaluated as an alternative logging method to extract salvage timber uphill direction after winter storm damage. Field measurements were conducted in Tavşanlı Forest Enterprise Chief located in Kütahya Forest Regional Directorate where storm damages often occur during winter season. The time motion study was implemented in two slope classes (35% and 55%) and two skidding distances (40 m and 60 m). It was found that total cycle time of timber extraction operation using portable winch ranged between 3.13 and 4.64 minutes. The average productivity was found to be 3.08 m3/hr ile 4.44 m3/hr. Statistical analyses indicated that productivity was mostly affected by log volume.