Determining the vibrations transmitted by electric chainsaws in conifer cross-cutting operation.

In forest operations, motor-manual tree felling and processing by chainsaw are very common in many Countries. In fact, the introduction of mechanised harvesting is limited in several Countries due to terrain conditions (e.g. steep terrain), ownership fragmentation thus making it difficult to introduce safe mechanised methods. Workers engaged in motor-manual operations using chainsaws are exposed to unfavourable environmental conditions that can lead to occupational diseases over time. The main hazards associated with chainsaw use include noise, vibration stresses, and the exposure to wood dust and exhaust gases. In this study the vibrations transmitted to the hand-arm system during cross-cutting operation were measured. They are responsible of negative consequences for the vascular, neurological and muscular systems and for the bony tissues. In order to analyse the outcome of different factors on both vibration characteristics and forest workers exposure in chainsaw handling, the following aspects were considered: - chainsaws: two cordless electric chainsaws powered by Li-Ion batteries were compared to two wired electric chainsaws; - forest operators: chainsaw were handled by three forest workers with high training level and experience; The chainsaw vibrations were measured in conifer cross-cutting operations. The main results obtained allow to state some considerations: - the values of vibrations transmitted to the operator resulted lower for cordless electric chainsaw than wired electric ones; - operator behaviour in chainsaw’s handling may influence the amount of vibrations measured. Cordless electric chainsaws appear functional and suitable especially for pruning and garden operation on small wood diameters (about 20 cm), while wired models are more functional for non-professional use.