Productivity Study of WoodPac Bundling of Logging Residues and Small Stems

A new approach for procuring logging residues has been introduced, in which the residues are compacted into cylindrical bales known as composite residue logs (CRLs). Some large-scale productivity studies have been undertaken on different bundling machines, and preliminary calculations on the possible benefits associated with bundling have been based on limited material or on prototypes. The aims of the study presented here were to measure the effects of concentrating forest fuel on bundling productivity with a WoodPac machine and to test if there was a difference between bundling logging residues and small stems. The results show that the WoodPac machine produced 19.3 bundles per effective hour (E0), equivalent to 28.5 MWh, in a clear-cut spruce stand. Productivity was not influenced by the amount of green mass as long as there was more than 5 Mg per 100 m driving distance and the material was collected in heaps. About 20% of the handled material was shaved off, mainly as fine material, so 24% more was handled than appeared in the bundles. Productivity could be raised to 24 bundles per E0 with logging residues, but with young stems the productivity may be 50% lower. Forwarding bundles was at least 2.5 times more productive than forwarding loose logging residues. In conclusion, bundling could be of interest when economical and environmental aspects of the whole chain are considered.