Comparison of Harvesting Productivity and Cost of Cable Yarding Systems

Abstract

This study was conducted to provide field-based harvesting study information which can be used to select an optimal cable system for certain work conditions on steep grounds (>20° ground slope) in Korea. To accomplish this study objectives, we evaluated three cable yarding systems (RME-300T tower-yarder, Chuncheon tower-yarder, FARMI tractor winch) working in typical work conditions for their yarding productivity and operational efficiency. Those yarders are commonly used for removing logs or trees on steep grounds in Korea. Under the same work conditions (average DBH of tree to be cut, 20 cm; yarding distance, 60 m; lateral yarding distance, 10 m; and machine utilization rate, 70%), the average productivities were 33.04 m 3 /day, 38.47 m 3 /day, and 14.17 m 3 /day for RME-300T, Chuncheon tower-yarder, and FARMI, respectively. Our standardized cost comparison study also showed that the yarding cost was highest at 37,835 won/m 3 with FARMI, followed by RME-300T at 25,105 won/m 3 for the same work conditions. We found the lowest yarding cost with the Chuncheon tower-yarder at 20,520 won/m 3 which was resulted primarily from high yarding productivity at the yarding distance (60 m). Our analysis suggested that a small machine such as FARMI could be a low-cost yarding machine option for a cable yarding job with a short yarding distance (40 m or less). The Chuncheon tower-yarder is well suited for a mid-range yarding distance job in Korea, ranged between 40 to 140 m. If yarding distance were longer than 140 m, the RME-300T tower yarder appears to be most cost-effective.

Harvesting Cost and Productive of Tree-Length Thinning in a Pinus densiflora Stand Using the Tower Yarder (HAM300)

“…Operating costs were those incurred when the machine was working, including fuel and lubricant costs. Machine costs were calculated using a machine rate calculation that takes into account annual machine usage time (Miyata 1980;Han et al 2014;Cho et al 2015).…”

“…Where D is depreciation cost, P is the initial investment cost of equipment, S is the salvage value, and N is the economic life in years (Miyata 1980;Han et al 2014;Cho et al 2015).…”

“…Because this amount must be considered as an opportunity cost when it was invested in other purposes, the average yearly investment (AYI) needed to be calculated (Miyata 1980;Han et al 2014;Cho et al 2015).…”

“…Accordingly, the annual interest could be calculated as AYI×interest rate (%), the insurance cost could be calculated as AYI×insurance rate (%), and tax could be calculated as AYI×tax rate (%) (Miyata 1980;Han et al 2014;Cho et al 2015).…”

“…In terms of studies on whole-tree logging systems, Lee et al (2013) analyzed the cost and productivity using a swing yarder, whereas Cho et al (2014) examined the cost and productivity from felling using a chainsaw to yarding using the tower yarder (Koller K301-4). For tree-length logging systems, Han et al (2014) studied the cost and productivity of different machines, including a tractor-mounted yarder (Chuncheon Tower Yarder), tower yarder (RME-300T), and tractor winch (FARMI), whereas Cho et al (2015) analyzed the operational costs and productivity of a tower yarder (Koller K301-4). Thus, there has been many researches on the RME-300T, Koller K-300, 301, Chuncheon Tower Yarder, and swing yarders, but there is still little information regarding the cost and productivity of the tower yarder (HAM300) developed domestically in 2014.…”