This study was carried out on very steep and difficult terrain. Whole trees were logged uphill to the forest road by a Koller K300 cable crane. Investigations were carried out by time studies for which the repetition time measurement method was selected. Through time studies, the productivity and cost of the Koller cable system were evaluated. Koller K300 cable system's time of transportation for one time from distance 100, 200 and 250 in arranges the average 6.24, 8.05 and 10.10 min in the Salalet Hill felling area. The productivities of Koller K300 cable system at these different distances were found as 6.6 m(3)/h (100 m), 5.5 m(3)/h (200 m) and 4.9 m(3)/h (250m). The average load is two piece timbers. The cost of the Koller K300 cable system was found as $4.2 per m(3). Operation phases most effective on total time and productivity were determined as lateral outhaul, hook and inhaul. The felling sequence should be chosen with consideration for efficiency, wireless should be used between yarder operator and choker setters for communication, and much more chokers should be used for loading. Further yearly working times of machines should be increased. (c) 2006 Elsevier Ltd. All rights reserved.