Multicycle rut depth in forwarding

ManuscriptThe role of environmental effects in timber harvesting is deserving more importance in decision making and logging planning. Therefore more emphasise has to be put on planning system, so that environmentally sensitive sites for a certain harvesting system can be recognised and the best suitable machines selected for given terrain conditions. Some rut depth models based on WES-method have been developed for single pass rut and only a few for multipass. Forwarders usually have different wheel configuration and wheel load between axles, and the wheel load varies during a transport cycle. In order to test the suitability of some multicycle model in Nordic forestry conditions some test drives were organised and the rut depth after each wheel pass recorded. It was found out, that a multipass coefficient model using wheel numeric as the input variable and a simple multipass model gave acceptable results, but more tests are needed to test the total goodness of the method