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

Eunjai Lee,Koohyun Cho,Yunsung Choi,Minjae Cho,Sangkyun Han,Jaeheun Oh,Sangjun Im

doi:10.3390/f12070908

Abstract

Cable yarding technology remains the most effective operation in steep terrain harvesting systems; however, it has limitations and challenges. Using cable yarders (tractor-, truck-, and excavator-based) to extract tree lengths and whole trees has been common since the late 20th century in South Korea, and cable yarding operations were developed in the late 1800s in the United States and Europe. Machine potential and limitations must be understood to ensure the widespread use of technology, strong cooperation, and optimal selection of machinery size. We reviewed the literature on tower yarder performances from 1990–2021 to determine the alteration of yarders and its productivity pattern and obtained 23 papers; <2 publications per year discussed the determination of cable yarding productivity. We selected independent variables (e.g., silvicultural treatment, harvesting method, and cycle log volume) for cable yarding that would likely affect productivity. Data were analyzed to compare productivities under silvicultural treatment, the harvesting method, and yarding direction and identify the interaction mechanical power (i.e., lifting capacity and machine power), yarding distance, and slope. Cable yarder productivity rates generally depended on the silvicultural treatment, harvesting method, and yarding direction, particularly in clear-cut, tree-length, and uphill yarding operation activities. The lifting capacity, machine power, and slope had no significant correlation with yarders’ productivity, particularly in thinning operations, whereas, in clear-cut productivity, it was influenced by these variables. The results contribute to improving operation activities for cable yarding systems and towards future research directions.

Highlights

Introduction iationsVarious harvesting systems have been developed to achieve economic and environmental sustainability under complex variable conditions, such as geophysical conditions, industrial infrastructure, and labor availability [1,2,3]
Ground-based harvesting systems can be described as the dragging or forwarding of felled trees from the stump location to landing by a skidder or forwarder that travels over the ground [4]
In addition mechanized timber harvesting has been developed and has been preferred over the last few decades owing to its productivity and cost efficiency benefits and because of its reduced road infrastructure and safety risks [2,7,8]

Summary

Introduction

Introduction iationsVarious harvesting systems (e.g., ground-based, cable, and aerial harvesting systems) have been developed to achieve economic and environmental sustainability under complex variable conditions, such as geophysical conditions, industrial infrastructure, and labor availability [1,2,3]. Cable systems using a sledge yarder and a tower yarder require cables to haul or extract trees on steep terrain for landing, whereas, in aerial systems, logs are hoisted and derived above the ground by a helicopter or airship [5,6]. While cable logging systems became well known in the USA and Europe in 1970, the mechanized extraction of trees by a cable yarder in Korea commenced at the end of 1980 under the cut-to-length method in clear-cut and thinning treatments [20]. Tower yarders are divided into three main types: small, medium, and large [43]. Small mobile cable yarder: A 19–186-kW vehicle (include tractor, truck, and excavator) is required, and the tower height ranges from 4.5 to 10.0 m. Power is provided by the power take-offs, and two or three guy lines are required

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Conclusion