Comparison of Productivity and Cost of Timber Extraction by Farm Tractor, Skidding vs. Forwarding in Northern Iran

This paper presents research results of the comparing timber extraction using a farm tractor at two different methods including forwarding and skidding. Time studies were conducted to qualify the productivity and the operational cost of logs forwarding and skidding by farm tractor in cut-to-length and tree length method in a plantation in even terrain conditions in Shafaroud, Northern Iran. Farm tractor is commonly machines which are used in many part of Iran as Northern part. The models for effective time consumption, total productivity and work phase models are calculated. The time consumption and productivity of log extraction with a farm tractor depends on several variables such as distances and slope, number of logs per cycle and volume. The average load per cycle was 3.84 m3 and 0.5 m3; the average one-way skidding distance was 167 and 233 m, in the forwarding and skidding, respectively. The average travel speeds of un loaded tractor were 4.54 km/h and the average speeds of loaded tractor were 0.39 and 0.82 km/h in forwarding and skidding, respectively. The average output was 3.44 and 1.07 m3 /effective hour; the average cost was 5.86 and 19.7 US$/m3 for forwarding and skidding, respectively.