New biomass harvester twice as productive
Studies in Scandinavia show a new feller-compactor unit greatly increases productivity over older models, suiting it for small-diameter clearing work.
By Scott Jamieson
First thinnings have been neglected to great extent in Finland and Sweden due to high harvesting costs. The whole-tree bundler was developed in Finland by Fixteri Oy to rationalize the integrated harvesting of small-diameter energy wood and pulpwood and to reduce transportation costs through load compaction. In field studies by the Finnish Forest Research Institute (Metla) and Skogforsk (Sweden), the new Fixteri whole-tree bundler was twice as productive as the previous model.
The whole-tree bundler consists of a Logman 811FC base machine, Nisula 280E+ accumulating felling head, and Fixteri FX15a bundling unit. The whole-tree bundler cuts and compacts the small trees. The Finnish Forest Research Institute (Metla) and Skogforsk (Sweden) used field trials in stands of varying densities and stem sizes to test the productivity of this third version of the the Fixteri FX15a.
The results indicate that the performance of the new Fixteri FX15a whole-tree bundler is significantly higher than that of the previous prototype, Fixteri II. An average performance per effective working hour of 9.7 m3 was recorded for the new Fixteri model when the density of removal was 3,213 trees per hectare and the average whole-tree volume was 28 dm3 (.028 m3). With an average whole-tree volume of 44 dm3 (.044 m3) and removal density of 2,016 trees per hectare, a performance of 11.9 m3/E0-h was reached. At an average whole-tree volume of 84 dm3 (.084 m3, or otherwise known as a sawlog in most of Canada) and removal density of 1,266 trees per hectare the performance was 13.8 m3/E0-h.
In the study of Nuutinen et al. (2011), an average performance per effective working hour of 4.6 m3 was achieved with the previous Fixteri II when the density of removal was 1,400 trees per hectare and the average tree volume was 40 dm3 (.04 m3). Respectively with an average whole-tree volume of 31 dm3 (.031 m3) and removal density of 2,850 trees per hectare, a performance of 5.1 m3/E0-h was reached. Thus, the performance of the new Fixteri model is increased by 1.9–2.6 times, depending on the stand density and mean tree volume of the removal.
Preliminarily, the higher performance level of the Fixteri FX15a is a result of increased multi-tree cutting and improved capacity of the bundling unit.