Productivity of whole-tree bundler in energy wood and pulpwood harvesting from early thinnings

摘要

First thinnings have been neglected to great extent in Finland because of high harvesting costs. The whole-tree bundler (Fixteri) was developed in order to rationalize the integrated harvesting of small-diameter energy wood and pulpwood and to reduce transportation costs through load compaction. The operation of the whole-tree bundler is composed of cutting and compaction processes. In the present study, the productivity level and the performance characteristics of the second version of the whole-tree bundler (Fixteri II) in integrated energy wood and pulpwood harvesting from first thinnings were defined on the basis of a time study. When the mean volume of removed whole trees averaged 20 dm3 at the stand, the productivity of Fixteri II per effective working (E0 excluding delays) hour was 3.4 m3/(E0) and with an average removal of 75 dm3, it was 6.1 m3/(E0). When compared with the first prototype of the whole-tree bundler (Fixteri I), the productivity of Fixteri II was 38-77% higher, depending on the stand density and mean tree volume of the removal. The higher performance level of Fixteri II stemmed mainly from the increase in multi-tree cutting and from the introduction of grapple feeding of the bunches. Furthermore, the better hydraulic capacity of the base machine enabled a higher level of simultaneous working processes.