Estevastus ja estetyö maastossa liikkuvien koneiden kulkumalleissa

KatsausArtikkelissa tarkastellaan metsäkuljetusten maastoluokituksen ja kulkumallituksen välistä vuorovaikutusta sekä kehitetään teoreettinen viitekehys estevastuksen ja estetyön laskemiseksi. Pienoismallikokeiden, pienen empiirisen aineiston ja kirjallisuustarkastelun avulla yritetään estevastus konkretisoida siten, että tulevissa maastokokeissa estevastuskomponentti voitaisiin ottaa huomioon sekä kokeita suunniteltaessa että tuloksia analysoitaessa. §

Rut depth model for timber transport on moraine soils

The increased awareness of environmental issues has created a need for evaluating the usefulness of mobility models for Nordic forestry conditions. A frame of reference based on the WES-method was used for developing empirical rut depth models for moraine forest sites. It was found that the penetration resistance in critical layers alone was an adequate soil input variable, even if the studied soils had very large variations in stoniness. When comparing the results with earlier models developed for organic soils, it was found that the same models apply for both types of soils. The method and models seem reliable enough for avoiding operations on too risky soils

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