Productivity Analysis of Mid-Size Cable Yarding Operation based on UAV-captured Video Sequences

One of the most preferred timber extraction methods in steep and mountainous terrain conditions is cable yarding. In recent years in Turkiye, mid-size cable yarders have begun to be used frequently in steep forest areas where intensive forestry is carried out. In order to make more effective use of cable yarders and achieve maximum productivity, timber extraction operations must be planned in the most appropriate way and implemented in the field accordingly. The productivity of mechanized equipment used in harvesting operations is mostly determined by using time study analysis. In traditional methods, time measurements are carried out by observing the work stages with time recording devices (stopwatches) in the area where the machine operates. Since timber extraction by using a cable yarder takes place in steep and tough terrain conditions, difficulties may be encountered in applying time analysis in the field. In this study, it was aimed to obtain high-resolution digital video images of the activities of cable yarding operation with an Unmanned Aerial Vehicle (UAV) and to calculate productivity through time study analysis on these images. In the study, Tajfun MOZ 500 GR model mid-size cable yarder was evaluated during a timber extraction operation in Köyceğiz Forest Enterprise Chief (FEC) located in the city of Muğla in Turkiye. Besides, statistical analysis was performed to estimate the effects of factors such as average product length, product diameter, lateral yarding distance, number of pieces and total product volume per turn on the productivity of the cable yarder. The results indicated that UAV video images can be an effective alternative method to conduct time study analysis and productivity estimations. It was found that the productivity of the mid-size cable yarder was 11.76 m3/hour. During the operation, pulling mainline to the product and choker setting was the most time-consuming work stage, followed by the time loaded carriage reaching the landing. The statistical analysis indicated that there was a significant relationship (p