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ŠUMARSKI LIST 11-12/2016 str. 35     <-- 35 -->        PDF

time consuming components of total yarding time were load hookup and travel of loaded carriage. Delays were 13.9% of the total yarding cycle time; and ranged from 87% in operational delays to 13% in technical delays. Table 5 shows detail time study for total yarding cycle.
The operation cost of the Urus MIII skyline yarder was based on fixed and variable costs. Fixed costs include: the cost of interests, depreciation, tax and insurance. Depreciation was calculated according to economic lifetime of 10 years. The fuel consumption of Urus MIII skyline yarder was 5 l/hr and it was measured during timber extraction operations. Lubricant costs were assumed to be 23% of total fuel cost (Ozturk, 2004). Total cost of Urus MIII skyline yarder was 30.00 €/hr. Detailed costs of skyline yarder are shown in Table 6.
In this study, the most time during skyline yarder operations has been spent for travel of loaded carriage phase (35.5% of total time). Total yarding time increased as the yarding distance increased. The average delay free time consumption of yarding was approximately 13.9% lower than the time consumption with delays. The average number of timber per load was 2, approximately, the average yarding distance was 253 m and the average volume per a cycle was 1.187 m³. By increasing yarding distance, productivity of Urus MIII skyline yarder and total time of a cycle time decreased. An inverse relationship of productivity with yarding distance and a direct relation with volume transported are visible in figures 4 and 5.
CONCLUSION AND DISCUSSION
ZAKLJUČAK I DISKUSIJA
This paper shows the results of research of yarding timber by Urus MIII yarder. The average total time consumption with delay time per cycle was 6.43 min. The average lost time per cycle was 0.52 min. The average load volume was 1.187 m³/cycle and load averagely consisted of 2 pieces. In this study, the productivity of Urus MIII skyline yarder was 10.60 m³/hour and daily productivity of yarder was 84.80 m³. Aykut et al. (1997) reported that productivity of Urus MIII skyline yarder was 8.60 m³/hour for 240 meters of line length and Caglar et al. (2003) found it to be 3.80 m³/hour for 600 m line length. Ozturk (2004) reported that productivity of Urus MIII skyline yarder is 12.90 m³/hour for 350 meters of line length. This study when compared to previous ones shows higher productivity of the yarder. In this harvesting area, the shrubs and ground cover wasn’t dense and the workers were able to move much easily in the area. In this study, the average fuel consumption was 5 liters. In this study, the costs of the Urus MIII skyline yarder were 30.00 €/hour and 2.83 €/m³, respectively. Ozturk (2004) mentioned that the cost of Urus MIII skyline yarder was 5.24 $/m³. The average speed of unloaded carriage (downhill) was 70 m/min and the average speed of loaded carriage (uphill) was 184 m/min.
In this study, the cleared corridor for skyline yarder operation was 2.5 meters and the width of this corridor was