To be presented with the permission of the Faculty of Agriculture and Forestry of the University of Helsinki for public criticism in the Walter Auditorium of the EEbuilding (Agnes Sjöbergin katu 2) on May 28 th , 2014, at 12 o'clock noon.
ABSTRACTThe eucalyptus has recently become an important timber species in Thailand, particularly in relation to timber supply within the pulp industry. Demand for raw material is continuously increasing, but harvesting techniques continue to rely on old-fashioned methods of harvesting, which are motor-manual and labour-intensive operations. These harvesting operations typically provide relatively low productivity and are time consuming. This study addressed the timber harvesting potential in Thailand including: average productivity, identifying ineffective work phases, and how work performance can be improved. Therefore, the study was conducted to analysis existing timber harvesting systems as a whole and compare alternatives, and to explore improvements in forest harvesting systems in Thailand through work study, working postures analysis, and simulation. Work study allowed the researcher to understand in detail the conventional harvesting systems and obtain information regarding work activities and time allocations. Harmful tasks and awkward working postures were evaluated by working posture analysis. Simulation allowed the researcher to examine the impact of changing harvesting systems. The study confirmed that motor-manual operations have rather low production rates compared to intermediate and fully mechanized harvesting techniques, which are applied in other parts of the world. The most unproductive work phase is cross-cutting, and further research should pay attention to this work phase. According to the working postures analyses, the most problematic working postures found for manual tasks included stacking, delimbing, and loading. Simulation findings suggested that reorganization of job sequences is one major possibility for improving productivity. Log length and tree size also displayed a significant effect on overall productivity. Further research should consider enhancing the system with partial mechanization, such as farm tractors, skidders and multi-tree-handling harvesters. Education and training are also important measures to increase not only work performance, but also to improve work safety.
