Efficiency of a Woody 60 processor attached to a Mounty 4100 tower yarder when processing coniferous timber from thinning operations

Processor tower yarders (PTY) represent the current state of yard- ing technology being extensively used in mountainous conditions such as those from Central Europe where they were also developed and used for the first time. In proper technical conditions which are mostly related to forest road infrastructure such equipment may be introduced by technol- ogy transfer in other countries such as Romania where they could replace actual less-efficient forest equipment used in steep terrains. The aim of this study was to evaluate the efficiency of such equipment in conditions of thinning operations by adapting a time study to the general concepts and by using data collection techniques to suit the operational conditions im- posed by such equipment. In conditions of a mean tree volume of 0.21 m 3 × tree -1 , the results of our study indicate net production rates as high as 12.72 m 3 × h -1 when processing trees on landing, which could be also im- proved up to 17.52 m 3 × h -1 if the PTY have been be adequately installed on the forest road. Another key aspect which could improve the efficiency of such equipment performing landing operations is the number of planned and realized wood assortments since the time expenditure was affected by their number. Given the reduced impact on forest soils as well as the in- creased efficiency of tower yarders, our study concludes that there would be a lot of potential in actually using them in the Romanian forests lo- cated in steep terrain, if proper transportation infrastructure would exist. Keywords efficiency, time expenditure, productivity, processor tower yard- er, landing operations, traditional harvesting equipment