Chain saw operators productivity and work stress on high buttress tree felling in natural rain forest in Central Kalimantan (Indonesia)

In general, there are three basic types/methods of chain saw operator's body position in doing mechanical tree felling in natural forest i.e; felling with squat, felling with standing deeply bending forward and standing with both arms in extreme position in the shoulder joint. However, the body position of chain saw operator in high buttress tree felling is usually in standing with both arms in extreme position in the shoulder joint. The extreme body position above does not only generate static muscular load causing early fatique and pain in the shoulder joint (Hagberg, et al, 1987) but also cause physiological load during work (Ayaz, 1987). For this matter, a study was conducted for the improvement of worker's productivity and work stress by introducing a new method of body position's felling technique. The investigation took place at Central Kalimantan in 1989. The results of this research are as follows : 1. From physiological variable point of view, the chain saw operator's work stress during work is higher than the limited work stress level recommended by international medical opinion. 2. New felling technique applied on high buttress tree of 150 to 300 cm can reduce work stress rate about 3-8 beats/min. While, if it is applied on high buttress tree of 300 cm causes the operator chain saw's work stress about 1-4 beats/min lower than operator chain saw's work stress in felling of tree with conventional method. 3. Productivity rate with new felling method applied on buttress high of 150 cm - 300 cm and 300 cm are about 19.298 cubic m/hr and 18.207 cubic m/hr. The productivity rate with conventional method applied on high buttress of 150 cm-300 and 300 cm are 22.974 cubic m/hr and 24.947 cubic m/hr. 4. Although the use of new method on high buttress tree felling causes negative effect in work productivity, in fact it can increase the forest wood utilization about 2.63 percent-4.27 percent