Implementing small scale skyline integrated with a portable winch in logging operation and evaluating the productivity of the system

The forests resources should be managed according to principles of precision forestry to meet needs of public in long-term. Particularly, forest operations during production of wood-based products should be conducted according to precision forestry approach. Thus, "small-scale forest operations", which are used in non-industrial and site specific forestry based on international literatures, provide alternative methods well suit with precision forestry concept. In this study, a small-scale cable yarder integrated with a portable winch was considered as alternative method in logging operations for the first time in Turkey. In the study, uphill cable logging was analyzed considering productivity. The cable system was implemented during harvesting activities performed in Soğukpınar Forest Enterprise Chief located in Bursa Forest Enterprise Directorate. Two slopes (34-50%, 50-70%) and two cable lengths (100 m, 200 m) were implemented in the field. The work stages to be evaluated in the cable logging operation are; unloaded carriage reaches loading place over skyline by gravity, dropping hook onto ground and pulling hook to side of forest products, attaching forest products to hook using chokers, pulling hook back to carriage and pulling loaded carriage uphill to landing area over skyline line, dropping hook onto ground and pulling hook to carriage after unloading products. The factors (slope, yarding distance, lateral pulling distance, load volume, log length) effecting productivity of cable logging operation were determined. Total load volume was evaluated in three classes (low, medium, high) to investigate effect of total volume carried on each turn. In the four skyline applications evaluated in the study, the average productivity was found to be 0.95 m3/hour for productive machine hour while it was 0.90 m3/hour for planned machine hour. According to the results, it was determined that the productivity of the mini skyline decreased as the ground slope and the yarding distance increased. Statistical analysis indicated that there was a significant (p <0.001) relationship between log sizes (volume and length) and productivity in four applications. On the other hand, it was revealed that there was a significant (p <0.05) relationship between lateral pulling distance and productivity in only the first application (34-50% slope and 100 m yarding distance. Considering the volume classes of the logs yarded in each cycle, it was determined that the productivity increased from the low volume class to the high volume class.