A solution for indirect mass assessment of timber during fully suspended yarding operations

This paper describes the theoretical approach followed to perform an indirect load mass assessment during yarding activities. The goal of this methodology is the mass assessment of the loaded biomass during the inhaul phase in cable logging operations.The theoretical approach proposed is based on the development and the use of mathematical model which, thanks to the measurement of the skyline deflection, slope and tensions permit to estimate the hauled mass. Indeed, as reported in literature, these parameters, together with the mass of the load, are strongly related each other. For this experiment an in-scale yarding line has been developed in order to control and monitor all these parameters. The precision and accuracy of the obtained results related to the mass estimations have been then compared with similar results obtained through manual surveys using tools commonly used by the forestry community.In conclusion the proposed methodology has shown to be reliable for an indirect mass assessment of loads during yarding operations. Indeed, if the line is adequately installed this monitoring system ensures better accuracy if compared with the common tools employed for timber assessment.