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ŠUMARSKI LIST 11-12/2016 str. 32     <-- 32 -->        PDF

The extraction of forest products is very difficult, expensive and time-consuming operation (Zimbalatti and Proto, 2010). Timber transportation is divided into two stages in Turkey. These are primary transportation and secondary transportation. Ground based timber extraction is done by skidders and adopted farm tractors, while in steep terrain cable systems Koller K300, Gantner and Urus MIII are usually in use (Ozturk and Senturk, 2006).
The aim of this study was to perform a time study to determine the productivity of Urus MIII skyline yarder in extraction of timber from spruce forests. The productivity of Urus MIII skyline yarder was investigated in harvesting area. Also, the hourly cost of Urus MIII skyline yarder was determined. The mounting and dismounting times were investigated according to terrain conditions such as ground slope, vegetation cover, and the shapes of terrain. The structure of total consumed time, time standards of work cycles and daily output standards for yarding distances were established.
MATERIAL AND METHODS
MATERIJALI I METODE
Study Area – Područje istraživanja
The study area is managed by Taslica Forest Office within the Artvin Forest Administration (Fig. 1). The total size of Taslica Forest Office is 15600 ha and road density is approximately 16 m/ha. The most important commercial tree species are Picea orientalis (L.) Link., Abies nordmanniana (Steven.) Spach., Fagus orientalis (Lipsky.) and Pinus sylvestris (L.). The research was conducted at compartments 33 and 34. The soil type of this region is loam. The average slope of harvesting area is between 60 and 75%. The yarder with a 400 meters line length was installed and for this work, an operator and three additional workers. A corridor for skyline yarder operation was 2.5 meters wide. The intermediate supports were not used along the yarding line length. Lateral dragging during the yarder operations varied between 5 and 23 meters. Timber yarding operations were carried out uphill. In harvesting area, all trees were felled and delimbed motor-manually with a chainsaw. The length of timber yarding was changed between 4 and 6 meters and the diameter of timber was between 28 and 62 cm.