INFLUENCE OF WHEELED TYPES OF A Skidder ON PRODUCTIVITY AND COST OF THE FOREST HARVESTING

Abstract

The objective of this study was to evaluate the influence of different wheel types of a skidder on productivity and cost of Pinus taeda L. wood extraction. The study was conducted in a forestry company located in the municipality of Mandirituba, Paraná state, Brazil. The technical and cost analyses included a time and motion study of the wood extraction activity. The productivity, operative efficiency, energy consumption and the production and operational costs were determined for the machines with different wheel types: SDP -skidder with rubber tires; SD2 -skidder with tracks on the two front tires; and SD4 -skidder with tracks on the four tires. Results showed that the activity that demanded most time in the operational cycle was the maneuvering of the machines to pick up more than one tree, resulting in lost of productivity and need of improvement in the operational planning. The skidder equipped only with rubber tires showed higher productivity and lower production cost in the longest extraction distances, caused by the higher operating speed of the machine. Keywords: Timber extraction; wheel types; operating efficiency. ResumoInfluência dos rodados de um skidder na produtividade e no custo da extração florestal. Este trabalho objetivou avaliar a influência de diferentes tipos de rodados de um skidder na produtividade e no custo da extração de madeira de Pinus taeda L. O estudo foi conduzido em uma empresa florestal localizada no município de Mandirituba, estado do Paraná, Brasil. As análises técnica e de custo englobaram um estudo de tempos e movimentos da operação de extração florestal. Foi determinado a produtividade, eficiência operacional, rendimento energético e custos operacionais e de produção das máquinas equipadas com diferentes tipos de rodados: SDP -skidder com rodados de pneus; SD2 -skidder com pneus dianteiros recobertos com semiesteiras e SD4 -skidder com os quatro pneus recobertos com semiesteiras. Os resultados mostraram que a atividade que demandou o maior tempo do ciclo operacional foram as manobras realizadas pelas máquinas para apanhar mais de uma árvore, ocasionando perda de produtividade e necessidade de melhoria no planejamento operacional. O skidder equipado somente com rodados de pneus apresentou maior produtividade e menor custo de produção nas maiores distâncias de extração, ocasionado pela maior velocidade operacional da máquina. Palavras-chave: Extração florestal; tipos de rodados; eficiência operacional.

Variables Influencing Working Time and Skidder Productivity in Wood Extraction

“…The large amount of time taken by the empty and loaded travel stages is in agreement with several authors, who affirm that this type of machine is active throughout most of the operational cycle, that is, undertaking empty and loaded travel (BEHJOU et al, 2008;LOPES et al, 2014). This shows that, in order to optimize the extraction operation with the skidder, it is necessary to perform the operation over shorter distances, because over longer distances, the time consumed during travel increases.…”

Analysis of Indicators and Cost of World Class Maintenance (Wcm) in Forest Machines

“…This result, although it does not show a significant difference, should be considered relevant, since, with the introduction of a maintenance system based on preventive maintenance, the maintenance cost of the machines was reduced. The values obtained for the maintenance cost of skidder were above the costs observed by Lopes et al (2014), studying the forest tractor skidder in the extraction of wood, in which they observed an average maintenance cost of R$ 102.30 per hour worked.…”

“…In this sense, researchers infer that forest harvesting activities represent high costs in the forest productive process, and can reach 50% or more of the industry wood costs, having, possibly, a great economic impact on the forest-based industry (GUEDES et al, 2017). Lopes et al (2014) and Silva et al (2010), studying the extraction and logging operations, respectively, identified that only the cost of mechanical maintenance can represent up to 60% of forest harvesting machine total cost, being clear the importance of the maintenance sector within the activity of wood harvesting.…”

Manutenção Preventiva Como Determinante Para Redução De Custos De Manutenção De Um Feller Buncher

“…Dado o cenário atual, as empresas vêm buscando avaliar todo futuro investimento e, nesse contexto, a manutenção de equipamentos de colheita florestal mostra-se como ponto chave, uma vez que seus custos podem variar de 50 a 60% do custo total do equipamento (SILVA et al, 2010;LOPES et al, 2014). Yamashina (2000) comenta que um dos principais modelos de manutenção utilizados é o World Class Maintenance (WCM), que utiliza como base a manutenção preventiva.…”