Productivity and cost analysis of cable yarding operations in flat terrain in the canton of Aargau in Switzerland

Protecting soils during forest operations is important, especially soils with limited bearing capacity that are being harvested during the wet months. These soils can sustain damage to their structure, and therefore site productivity can be reduced. Climate change may change weather patterns, and less frozen soil conditions will occur more frequently, forcing planners to search for alternatives to overcome this challenge. In this context, cable-based systems for tree yarding are one option to reduce potential damage to soils and remaining stands. Time studies were performed on three cable yarding operations in the canton of Aargau, Switzerland, aiming to understand the performance of cable-based systems in flat terrain. A statistical analysis was performed, and costs were calculated. The yarding productivity was 13.92-21.86 cubic meters over bark (m3ob) per productive machine hour. The payload was identified as the main variable significantly influencing the productivity of a yarding cycle. Overall, installation procedures of the yarder were the most time-consuming and expensive work step. Production costs were 70-102 CHF m3ob-1 (corresponding to 73-107 euro m3ob-1), including felling, yarding and roadside processing. This study confirms that the costs resulting from cable-based operations in flat terrain are high and the approach is not (yet) competitive with ground-based systems.