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

Abstract

Forests in Korea are mainly located in steep mountainous areas, where small-shovel-based extraction technology is widely used, with the level of mechanization undoubtedly low due to financial limitations. On this steep terrain, a better approach may be to use cable yarders, which can offer high revenues through cable-based extraction. Therefore, improving the efficiency of cable yarding activities in good-quality timber forests is necessary. The main objectives of this study were to (1) evaluate the productivity and cost of a cable yarder operation for tree-length clearcut treatment of a Larix kaempferi (Lamb.) Carr. stand and (2) compare the productivity efficiency of two yarder (K301-4 and HAM300) types. The productivity rates of the K301-4 ranged from 10.2 to 12.5 m3/productive machine hours, with corresponding costs of US $12.6–15.4 /m3. The productivity of the HAM300 was 26% lower than that of the K301-4 for a 30% lower cycle log volume while yarding and a comparable lateral distance. This study provides insights to support production and management decisions in the forest supply chain associated with planning cable-yarding operations.

A Literature Review on Cable Extraction Practices of South Korea: 1990–2020

“…These rates were significantly correlated with two different variables (Pearson's correlation, p < 0.05). This finding is consistent with those of previous studies such as Schweier et al [56], Baek et al [10], and Picchio et al [57], who reported that higher load capacities of yarders enable better performances, because they can control larger cycle log volumes compared to the machinery with low lifting capacities. This could be related to the low piece volume reported by Ghaffariyan [58] and Berendt et al [59], whose findings showed that increases in the harvesting productivity were associated with large log volumes, even though the extraction time per cycle increased.…”

Assessment of Physical Workload of Choker Setter in Tree-length Extraction Operation by Cable Yarder

“…The workload of the workers was also analyzed using VO 2max , increased heart rate (IHR), and relative heart rate (HRR). (21,25)…”

“…4). The resting heart rate (HR r , bpm), working heart rate (HR w , bpm), and maximum heart rate (HR max , bpm) were measured to analyze IHR (%) and HRR (%) as follows: (3,21) 100,…”

“…(19) Several previous studies have determined the performance of cable yarders to expand and improve the efficiency of wood production and supply chains in South Korea. (6,20,21) However, to our knowledge, none of the previous studies explicitly determined the physical workload of choker setters. Therefore, in this study we aimed to (1) determine HR and VO 2max variability for choker setters and the specific work process that incurs the highest workload, and (2) evaluate the total physical workload during cable yarding operations using a HAM300 tower yarder during the tree-length harvesting method.…”