Rubber-tracked forwarders – productivity and cost efficiency potentials

Abstract

Abstract Extraction of timber is expensive, energy intensive, and potentially damaging to the forest soil. Machine development aims to mitigate risks for environmental impact and decrease energy consumption while maintaining or increasing cost efficiency. Development of rubber-tracked forwarders have gained renewed interest, partly due to climate change leading to unreliable weather, and the urgency of reducing emissions. The increased cost of rubber-tracks compared to wheels are believed to be compensated by higher driving speeds and larger payloads. Thus, the aim of this study was to theoretically investigate how productivity and cost efficiency of rubber-tracked forwarders can exceed that of wheeled equivalents. The calculations were made with fixed parameters, to evaluate performance in different conditions, and with parameters from 2 500 final felling stands in central Sweden, to evaluate performance in varied working conditions. Scenarios were compared to a baseline corresponding to mid-sized wheeled forwarders. The results show higher productivity with the increased driving speed and load weight enabled by rubber-tracks at all extraction distances, with larger differences at long extraction distances. Assuming 15% higher machine price for the rubber-tracked forwarder, increased speed and load weight lead to 40% cost reduction for 400 meters extraction distance. Furthermore, a rubber-tracked forwarder is likely to give access to a larger part of the harvest areas during longer seasons. The year-round accessible volumes are estimated to increase from 9% to 92% with a rubber-tracked forwarder. With rubber-tracks, good accessibility can be combined with low soil impact in a favourable way for both industry and ecosystem.