Preliminary Tests of a Hybrid Cable Splice (Synthetic–Metal) to Innovate Timber Harvesting in the Mediterranean Forestry Sector

Abstract

Forest operations in the Mediterranean basin are still largely based on lowly mechanized systems. In this context, hauling is generally performed with equipment deploying steel cables, such as winches on farm tractors or skidders. In the last decades, several efforts focused on the substitution of steel cables with synthetic rope to improve safety, comfort and productivity. Despite the expected benefits, these efforts were generally frustrated due to the higher cost and lower duration of synthetic cables. These are relevant constraints, particularly for Mediterranean forest companies, which feature a relatively low financial capacity. As a possible solution, the present study introduces a hybrid splice of steel and synthetic cables, merging the benefits of the two materials. For that purpose, several possible splicing solutions were tested. The most efficient splice proved capable of withstanding up to 7.6 t of tension in the laboratory. In the forest, it allowed the extraction of about 450 t with a skidder before breaking. On a farm tractor, it extracted over 700 t without failure. Preliminary tests and the positive feedback of the operators proved the potential of this solution. Further research is ongoing to create a stronger splice and reduce its diameter to allow its deployment in any type of winch.