Resumo

VARGAS ABASOLO, Imelda et al. Productivity of a forest harvester in commercial eucalyptus (Eucalyptus spp.) plantations. Rev. mex. de cienc. forestales [online]. 2012, vol.3, n.12, pp.57-102. ISSN 2007-1132.

The evaluation of productivity of a forest harvester was conducted in Eucalyptus plantations in Huimanguillo, Tabasco state. Field work included a full-time study of time and movements for nine days, where all activities that involved forest harvesting and its operator were registered. Unproductive activities were identified as caused by the harvester´s failures and the operator´s lack of training. Considering the eight effective working hours, the harvester works at 75.9% of its capacity, 21% of the total time per shift corresponds to corrective maintenance, mainly due to the breaking of the hydraulic oil hoses. It was concluded that no preventive maintenance program exists. At harvest, unproductive activities were detected, as well as a lack of a preventive maintenance program. For the productivity analysis, a model of the y = a + bx + cx² form was accepted. The regression models used are valid when the minimum volume of production is equal to or greater than 0.0126 m³, which corresponds to the volume of a log of 8 cm in diameter and 2.5 m long. The information was evaluated with and without unproductive activities (IT). The maximum productivity is obtained when there is an average volume of 0.5534 m³ generating a productivity of 25.4147 m³h^-1. For the second case, the maximum profit occurs with an average volume of 0.56627 m³ and productivity per hour of 27.7661 m³h^-1. A lower profit was generated when including unproductive activities compared with the ideal way that harvester should work.

Palavras-chave : Logging; harvest cycle; corrective maintenance; regression models; time and movements; volume.

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