A Robust Productivity Model for Grapple Yarding in Fast-Growing Tree Plantations
AbstractNew techniques have recently appeared that can extend the advantages of grapple yarding to fast-growing plantations. The most promising technique consists of an excavator-base un-guyed yarder equipped with new radio-controlled grapple carriages, fed by another excavator stationed on the cut-over. This system is very productive, avoids in-stand traffic, and removes operators from positions of high risk. This paper presents the results of a long-term study conducted on 12 different teams equipped with the new technology, operating in the fast-growing black wattle (Acacia mangium Willd) plantations of Sarawak, Malaysia. Data were collected continuously for almost 8 months and represented 555 shifts, or over 55,000 cycles—each recorded individually. Production, utilization, and machine availability were estimated, respectively at: 63 m3 per productive machine hour (excluding all delays), 63% and 93%. Regression analysis of experimental data yielded a strong productivity forecast model that was highly significant, accounted for 50% of the total variability in the dataset and was validated with a non-significant error estimated at less than 1%. The figures reported in this study are especially robust, because they were obtained from a long-term study that covered multiple teams and accumulated an exceptionally large number of observations. View Full-Text
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Engelbrecht, R.; McEwan, A.; Spinelli, R. A Robust Productivity Model for Grapple Yarding in Fast-Growing Tree Plantations. Forests 2017, 8, 396.
Engelbrecht R, McEwan A, Spinelli R. A Robust Productivity Model for Grapple Yarding in Fast-Growing Tree Plantations. Forests. 2017; 8(10):396.Chicago/Turabian Style
Engelbrecht, Riaan; McEwan, Andrew; Spinelli, Raffaele. 2017. "A Robust Productivity Model for Grapple Yarding in Fast-Growing Tree Plantations." Forests 8, no. 10: 396.
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