earticle

한국어

Today, most forest harvesting operations are carried out with modern forestry machines, and their efficiency depends not only on the performance of each forestry machine, but also on how they are used in combination and on various site characteristics. In Japan, forest harvesting is usually carried out using several forestry machines in combination, and the most typical forest harvesting system in steep terrain has four production systems: felling, yarding, processing, and forwarding using a chainsaw, swing yarder, processor, and forwarder, respectively. In this study, the system productivity of this forest harvesting system was evaluated in the combined machine productivity (CMP) and combined labor productivity (CLP) indices by using system dynamics simulation, focusing on the variation of system productivity when the speed of each production process is changed. As a result, it was found that the speeds of the yarding and forwarding processes, which depend on the extraction distance, are the potential bottlenecks of the Japanese forest harvesting systems. The system productivity of Japanese forest harvesting systems in steep terrain can be improved by replacing swing yarders with more powerful tower yarders and by increasing the travel speed or maximum load of forwarders.