Expanding Ground-based Harvesting onto Steep Terrain: A Review

Timber harvesting on steep terrain has always been, and will remain, a challenge in terms of economic viability, safety and environmental performance. For almost a century motor-manual felling coupled with cable yarding has been the most appropriate harvesting system, but new technologies and innovations have led to machines and systems being developed that are modernising the way we operate on steep terrain. Specifically, they provide the opportunity for the mechanisation of operations with proven improvements in both safety and cost-effectiveness. The additional development of cable-assist machines is potentially making a real step-change by expanding the operating range onto very steep slopes. This paper reviews these developments, the main engineering considerations of how cable-assist works, as well as the advances being made in terms of how such equipment is integrated into harvesting systems. The review also includes analyses of the operating guidelines that are either in place or being developed to help implement the systems.