Productivity and cost of a small-scale cable yarder in an uphill and downhill area: a case study in South Korea

Abstract

Tree diameter, topography, and stand accessibility have been major factors to consider when selecting the optimal equipment to extract logs from stump to landing area. In Korea, forest land has 6.4 million ha of forest, comprising 64% of its total land area. Small and medium (15-30 cm in diameter at breast height [DBH]) size of trees located on steep slopes (> 30 ) is approximately 80% of total forest area. Therefore, there has been an increasing interest in the application of a small-scale cable yarding system. We performed uphill and downhill yarding experiments using an 80 hp farm tractor mounted tower yarder (HAM300) to evaluate productivities and costs associated with primary transportation of tree length logs in mixed conifer stands. In addition, sensitivity analyses were performed to find the effects of different yarding directions and distances on yarding productivities and costs. Results showed that uphill and downhill yarding productivities were 9.04 m 3 /PMH

Performance Analysis of Log Extraction by a Small Shovel Operation in Steep Forests of South Korea

“…CTL-S clear-cutting operations in each unit were performed using a semi-mechanized system that employs a chainsaw for felling, delimbing, and bucking trees into 2-4 m logs, which are mostly used as pulpwood. (An alternative to the use of the SS, especially on steep slopes, is manipulating all logs at the stump, as described by Lee et al [10,28].) The SS operation utilized the gravity extraction technique, which involves throwing, rolling, and pushing logs, to move the logs to the roadside or landing area.…”

“…Logging operations (a.k.a., primary transportation), in which logs are transported from stumps to a designated roadside or central landing area using various extraction methods, are an important part of the timber harvesting process, but they can be extremely expensive and more time-consuming in practice than felling and processing [1][2][3][4]. Many studies have examined the performance of extraction methods on sites with differing characteristics in order to establish the logistics of extraction activities, such as ground-based extraction (skidding and forwarding) [5][6][7][8] and cable yarding [8][9][10]. It can be concluded from these studies that logging practices should be economically determined while maintaining a deep understanding of both the potential and limitations of the chosen method.…”

“…There are a number of past studies that investigate the TL-C method to describe, understand, and improve upon the efficiency of log production and associated operational decisions. Other studies focus on the productivity and operation efficiency of individual machines [21,22], comparing extraction performances among different cable-yarder technologies [23,24], and the effect of yarding direction (uphill vs. downhill) on productivity and cost [10,25] in order to support operational decisions. However, the use of the TL-C method for log hauling activities remains limited since this method requires not only a high skill level, but also an inherently high level of investment [26].…”

Performance Comparison for Two Cable Extraction Machines in a Larix kaempferi (Lamb.) Carr. Plantation

“…In cable yarding activities, the HAM300 and K301-4 (Koller Forsttechnik GmbH Austria) yarders (Figure 1) are the most frequently used. The HAM300 is a cable yarder powered by a 60 kW farm tractor manufactured by the National Forestry Cooperatives Federation of Korea [12], whereas the 84 kW diesel engine two-axle truck-mounted K301-4 system is produced by Koller Forsttechnik GmbH.…”

“…In Korea, no previous study has explicitly compared the HAM300 and K301-4 to highlight their differences and advantages. Many studies have rather focused on the productivity and operation of the HAM300 [12,17] and K301-4 [18]. In addition, the need for cost-effective technologies for steep terrain harvesting is increasing as cable-based extraction methods expand and improve.…”