Harvesting operations in eucalyptus plantations in Thailand

Abstract

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 EEbuilding (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.

Added-value innovation of forest biomass supply chains

“…Forest growth simulation Figure 16. Classification of a system model utilised for the discrete-event and forest growth simulations in this work (modified by Leemis and Park 2004;Manavakun 2014). A deterministic simulation model does not contain random variables.…”

“…Working time can be performed in one, two or three (not used) shifts under the working time schedules. It is notable that productivity estimates could lead to inaccurate results when estimating effective time because delays are already included in the simulation model (Manavakun 2014).…”

Productivity assessment of alternative timber debarking methods

“…chronometer, palmtop, data loggers) and time study forms. In addition, devices for measuring distance and operation speed, camera, clinometer, steel tape, caliper are used in time study work in the fi eld (Yıldırım, 1987;Gülci, 2014;Manavakun, 2014).…”

Development of economic and environmental metrics for forest-based biomass harvesting

“…After being felled with a feller in the cut-to-length harvesting solution, timber is delimbed and bucked into, for example, pulpwood logs for biofuels, at the stump [8]. Logs are then transported via a forwarder to the roadside [9]. With the WTH method, trees are felled then transported to the roadside with branches and the top intact.…”

“…With the WTH method, trees are felled then transported to the roadside with branches and the top intact. The whole trees are processed at the roadside into pulpwood logs [9]. After trees are felled and bucked with a chainsaw in a MMH system, they are skidded to roadside by a ground-based cable skidder [5].…”