The effect of preplanned skid trails and winching on a partial-cut

Abstract

This paper describes the results of a study conducted in the Sierra Nevadas located in California to determine the production rates, s.kidding costs and the extent of soil disturbance and compaction on two partial cut units harvested with a Caterpillar D-7F. A harvest unit with preplanned skid trails and winching was compared to a conventional harvest unit. Production for the unit with preplanned skid trails and winching was 11 percent less than the unit with conventional tractor logging. Skidding costs per unit volume were increased by 29 percent. The unit with preplanned skid trails resulted in four percent of the area in skid trails whereas the other unit had 22 percent of the area covered by skid trails. Regression equations were developed for individual subcycles and the total cycle time. Results indicate that total cycle time with winching is a function of skidding distance, skid trail slope, number of logs per turn, volume per turn, number of winching cycles and the average winching distance.