Productivity of a prototype truck- mounted logging residue bundler and a road-side bundling system

Abstract

When recovering logging residues (LR) for bioenergy its density should be increased before road transport, otherwise a low proportion of the trucks' load capacity will be used. One way this can be currently done is to compress LR into bundles that are forwarded to roadside landing. A less well-developed alternative is to forward loose LR and bundle it at landing. In the presented study, a prototype specifically developed for road-side bundling was found to produce larger, heavier bundles than bundling machinery intended for in-field use (mean length, diameter and raw bulk density 4.7 m, 0.8 m and 285 kg m-3, respectively, with 299-445 kg oven dry matter per bundle). The machine was also at least 30% more productive than previously described in-field bundling systems, producing 14-19 bundles per productive work hour (PWh), equivalent to 5.2-7.8 oven-dry tonnes PWh-1. Bundles were estimated to use 67-86% of an LR truck's 30 tonnes load capacity, similar to proportions used when transporting loose LR. However, a continuous feeding and compressing process would probably almost double productivity, while longer bundles would enable full use of truck load capacity. With such improvements bundling at road-side could provide a viable alternative to current LR-recovering systems.