Performance of tracked excavators equipped with grapple-saw stacking treetops in poplar plantations

In recent years, the cost of manpower increased in Southern Europe. This has encouraged companies to improve the mechanization level of all activities. Purpose-built machines are very expensive, so in this transition phase, there is a tendency to purchase multipurpose machines to reduce depreciation costs. In this scenario, excavators play a fundamental role because they can be used in many activities by changing the working tools. In poplar plantations, excavators with grapple saws and tracks are usually used to move the residual biomass. This work aimed to analyze the performance of excavators with a grapple-saw during the stacking of residual biomass in poplar plantations. Six excavators that varied in power and mass were analyzed. The data analyzed showed that productivity is directly proportional to the machine's power and mass (0.15 t h-1 kW-1 and 0.75 t h-1 t-1). Furthermore, productivity is linked to the opening size of the grapple (6.43 t h-1 m-1 of opening). In conclusion, on the basis of the results obtained, it is possible to confirm that the excavators can be valid machines also in forestry activities independently of their nominal power and gross mass.