Modeling Productivity and Estimating Costs of Processor Tower Yarder in Shelterwood Cutting of Pine Stand

Cable-based yarding technology has had a long tradition on steep slopes in Europe, and the new implementation of functions recent decades favored operational efficiency lower extraction costs. The main goal this study was to evaluate performance Syncrofalke 3t truck-mounted Processor Tower Yarder (PTY) terrain, coniferous forests managed with shelterwood system. In particular, aim determine PTY productivity costs, attention parameters that could increase effectiveness. carried out Sredna Gora Mountains, Central Bulgaria, pure Scots pine stand, trees average DBH = 34 cm height 22 m. six corridors 120 work cycles tree up hill, 28° (53%). mean 15.20 m3 per productive machine hour (PMH) 12.29 scheduled (SMH) mainly influenced by yarder unit. Under given conditions, significantly increased if more than one (at least two trees) were attached extracted cycle, since processor approximately twice yarder. gross costs studied calculated at 297.48 EUR PMH−1 16.17 m−3. variable (75%) predominate net distribution, followed fixed (15%) labor (10%). time, cost results obtained showed high level integration operations order achieve economic logging montane forest