PRODUCTIVITY AND ENERGY EFFICIENCY OF WINCHING OPERATIONS IN PINE STANDS IN MOUNTAINOUS REGIONS

Resumo

The objective of this study was to evaluate the productivity and energy efficiency of tree extraction in mountainous regions by means of a tractor with winch in two work team compositions: I: one tractor operator and a cable operator; and II: one tractor operator and two cable operators. The study was carried out in Vale do Ribeira region using a full tree harvesting system through a time and motion study in different conditions of extraction distance (6 to 135 meters) and log yard (5 to 241 meters), and land slope (from 7 to 37º). To evaluate the cycles, a regression analysis was carried out for each treatment and subsequently compared using the Graybill F test. Then a regression with a dummy variable was performed. The productivity was 9.26 m³ PMH₀^-1 with a cable operator and 12.12 m³ PMH₀^-1  at an extraction distance of 100 m; the specific fuel consumption was 44.26 g kW^-1 PMH₀^-1  in both treatments, and the energy efficiency was 4.92 g kW^-1 m³ with a forest worker and 3.13 g kW^-1 m³ with two forest workers. Consequently, although the specific fuel consumption was equal in both treatments, the increase in productivity resulting from the addition of a cable operator,improved  the energy efficiency in the extraction using a tractor with winch.