Timber Extraction by Farm Tractors in Low-Removal-Intensity Continuous Cover Forestry: A Simulation of Operational Performance and Fuel Consumption

Abstract

Farm tractors represent a possible option for forwarding operations in continuous cover forestry, given the generally lower removal intensities, relatively high dispersion of timber, and heightened concerns regarding the environmental impact of operations. This study evaluated the performance of a farm tractor fitted with an externally operated crane and a bunk for forwarding operations, using field-documented data on operational speed, production, and fuel use, as well as data from high-resolution video recordings for a detailed time-and-motion study. Using this knowledge, performance simulations were run based on extraction distance and log size, to describe the variability in fuel use, cycle time, and productivity, and to estimate the operational cost. The results of the simulation showed important differences in operational speed across different work elements, involving machine movement. Although the extraction distance had effects, log size was found as the important factor driving the variability in cycle time, productivity, fuel use, and cost. The differences in performance based on the variability in extraction distance and log size may serve as a guideline for operational planning, costing, and environmental assessment regarding emissions under various operating conditions.