Assessment of machine productivity for a feller-buncher, processor, and harvester: a case study in the southern pine plantations of Queensland, Australia

This research studied the harvesting and processing productivity of cut-to-length and whole-tree harvesting operations in the southern pine plantations of Queensland, Australia. Elemental time and motion studies were completed for the harvesting of each system, a cut-to-length harvester-processer and a whole-tree feller-buncher and processor were observed with productivities of 75, 382, and 171 m3/PMH0, respectively. From this study, characteristic productivity models were generated for these systems with logarithmic and linear curves most closely representing the observed conditions. It was found that the observed values for the harvester-processor were 15% greater than the Australian Logging Productivity and Cost Appraisal [ALPACA] regional harvesting model; wheras, the whole-tree-processing productivity observed exceeded the model’s estimation by more than twice and the operating conditions of the feller-buncher were outside the bounds of the model. Results indicated that the ALPACA model is likely not a good characterization of Queensland operation conditions and needs to be updated to include more-refined estimates of whole-tree operations and regional merchandising conditions. Furthermore, this work highlights the need for additional whole-of-systems productivity and economic reviews when determining the optimal harvesting system for cost reduction and value recovery (i.e. the maximizing of the economic outcomes from a harvest within the context of associated markets) among competing systems in the region.

本研究针对澳大利亚昆士兰州南部松木人工林的伐段式采伐（cut-to-length）与全树采伐（whole-tree harvesting）两类作业的采伐及加工生产效率开展了系统探究。研究针对两类作业系统完成了基础工时与动作研究，分别观测到伐段式采伐加工一体机（harvester-processer）、全树伐木归堆机（feller-buncher）及配套加工装置的生产效率依次为75、382及171 m³/PMH₀。本研究针对上述作业系统构建了特征性生产效率模型，其中对数曲线与线性曲线最贴合实际观测得到的作业工况。研究发现，伐段式采伐加工一体机的观测生产效率较澳大利亚采伐生产效率与成本评估（Australian Logging Productivity and Cost Appraisal, ALPACA）区域采伐模型高出15%；而全树采伐加工的观测生产效率超出该模型预估值的两倍以上，且伐木归堆机的作业工况完全超出该模型的适用边界。研究结果表明，ALPACA模型或许无法准确表征昆士兰州的采伐作业工况，亟需更新以纳入针对全树作业及区域造材适配工况的精细化预估参数。此外，本研究强调，在该地区的多种竞争性采伐系统中，为实现成本节约与价值回收（即在关联市场语境下最大化采伐作业的经济收益）而遴选最优采伐系统时，亟需开展更多覆盖全系统的生产效率与经济评估研究。