Zeitstudien beim österreichischen Erntezug im Forstamt Partenkirchen/Obb.

Summary A new logging-method, developed in Austria, was tested in an upper Bavarian mountainous forest-district. It is based on a semi-stationary debarker, combined with equipment for cutting the stems into lengths; simultaneously the logs were classified. It is installed on a central conversion-site. The trees were felled and limbed as far as possible without being turned. The stems were then yarded by articulated rubbertired skidders, equipped with double-drum winch and chokers, blade and rear supportblade. Later they were transported by trucks on the forest roads to the conversion-site. In the individual operations time-studies were carried out to analyse the working-processes and to explore their interdependency. The results, calculated by applying statistical methods and computer-programs, were expressed in diagrams, which can be used for the calculation of needed workers and machines for comparable conditions. This very efficient logging-method is then discussed. The high performance in the felling-operations (7.74 m³ p.h.) is remarkable. The time for loading the skidders and trucks was noticeably high. The influence of the slope on the skidders on the returntrip uphill is significant. Finally it is to be noted, that in spite of using big machinery for transport-operations (up to 7 skidders and 2–3 trucks) it was not possible to utilize the debarkers capacity.