Cable Corridor Installation Times For European Yarders
Authors
Karl Stampfer
University of Natural Resources and Applied Life Sciences
Rien Visser
Virginia Tech
Christian Kanzian
University of Natural Resources and Applied Life Sciences
Abstract
Cable yarding continues to be an efficient and effective harvesting system for the extraction of timber on steep terrain. Modern European silvicultural strategies result in smaller harvest areas, lower extraction volumes and a shift from clear-cut to thinning operations or single tree extraction. Yarder installation time has, especially as a proportion to the extraction time, increased significantly, resulting in higher extraction costs. This study recorded the set-up and take-down time of 79 cable yarder installations. Another 76 installation times were taken from previously published time studies, for a total sample size of 155. The factorial study design differentiated uphill-or downhill yarding, yarder size and whether or not it was the first installation at a landing, or subsequent parallel installation from the same landing area. The covariates recorded were corridor length, terrain slope, number and height of intermediate supports, and number of forest workers. Both a set-up and take-down time models were developed. This will help estimate future cable installation time requirements, and more importantly, provide improved cost estimates for the new silvicultural treatments.
