Logging residue bundling at the roadside in mountain operations

Abstract

The recovery of logging residue offers many benefits, and can be effectively performed with several techniques. This study presents the results of four distinct trials conducted on the Italian Alps with a truck-mounted bundler, and compares them with the figures obtained by the Austrian and German colleagues on the other side of the Alps. Average productivity varied between 14 and 22 bundles per productive machine hour (PMH), or between 10 and 15 bundles per scheduled machine hour (SMH). Mass production ranged from 3.1 to 4.3 oven-dry tonnes SMH⁻¹. If the machine is used for at least 800 SMH year⁻¹ bundling costs will range between €7 and 9 MWh⁻¹, which is within the profitability limit indicated in Nordic studies. Although bundling may represent an additional cost in the slash-to-chip chain, it offers the important benefit of efficient outdoor winter storage, which is crucial in a region where the supply and demand of fuel biomass are often diachronic. The truck-mounted bundler used on the Alps adopts the same mechanism and achieves the same performance of the Nordic forwarder-mounted application. The main difference lies in its superior road mobility, which is crucial when covering scattered landings.

Keywords:

• Bundling
• compact residue logs
• economics
• energy biomass
• mountain
• harvesting
• productivity

Acknowledgements

The authors gratefully acknowledge the technical and financial support of the Provincia Autonoma di Trento, received within the scope of the research project “Sofie 2”. Assistance during field data collection was also obtained from Dr Carla Nati, Dr Gianni Picchi, Mr Felicien Noël and Mr Jonas Salvador.