Levels of Vibration Exposure and Cutting Efficiency in Cross-Cutting Operations by Chainsaw

Tree felling with a chainsaw is one of the most dangerous operations, but it cannot be replaced by machines in many areas. Operators are exposed to many hazards including accidents, fatigue, fumes, dust, noise and vibration. This research focuses on vibration exposure and on how it is affected by the accuracy of saw chain maintenance. Although chain sharpening must be carried out according to the manufacturer's instructions, it is common practice to make errors in sharpening angle and chain depth gauge lowering. The aim of the study is to investigate the variations in both cutting efficiency and vibration exposure, considering three different depth gauge lowering levels (standard: 0.65 mm, over-standard: 1.0 and 1.3 mm) when cross-cutting several square beams of two species: European beech (high density) and silver fir (low density). The results show that the increase in cutting efficiency at higher depths was statistically significant for silver fir beams but limited overall (about 10%). On the other hand, the over-standard lowering of the depth gauge did not reduce the cutting time on beech. On the contrary, vibration exposure increased significantly from a minimum of 64% to a maximum of 133% compared to the standard level. These results show that the practice of lowering the depth gauge beyond the standard level is dangerous for the operator and has no real benefit in terms of cutting performance.