Production Equations for Tower Yarding in Coastal British Columbia

Cable yarding is an important means for primary extraction of timber on steep slopes and/or sensitive soils throughout the world. Comprehensive planning for cable yarding requires detailed production and cost estimates which can be made using production equations. Such equations can come from the literature or independent time studies. Both options depend on previously published studies either for direct use or to improve study design. An elemental time study was designed and used in an investigation of tower yarding in coastal British Columbia. A comprehensive statistical analysis was applied to the data including stratification, fitting regression equations, and hypothesis testing. The findings include a library of production equations applicable over a wide range of operating conditions