Impact of Hybrid On-Board Energy Storage Systems on Whole-Body Vibration Exposure in Quarry Excavators

Exposure to whole-body vibration (WBV) represents a significant occupational hazard in quarry activities, where operators use heavy equipment in a hostile environment. Considering the increasing focus on electrification to reduce the environmental impact of construction and mining machinery, this study evaluates the impact of hybrid on-board energy storage systems on WBV exposure. To this end, two different sampling campaigns were carried out to collect a specific dataset. Measurements were performed on both diesel and hybrid excavators operating in two quarries of different rock types. Following ISO 2631-1, the study focused on the intensity and frequency of the vibrations transmitted during each working phase. Statistical analyses were conducted to compare vibration levels between hybrid and internal combustion engine (ICE) excavators. Results show that hybrid excavators, when the diesel engine is off, produce a significant reduction in WBV values, up to 30%, during specific operational phases (rotation), thus confirming the positive effect of the hybrid system in energy recovery and assist modes. However, due to the predominant influence of loading and unloading phases, these improvements translate into a more limited reduction of daily exposure A(8). These findings highlight the importance of distinguishing between phase-specific vibration mitigation and overall daily exposure levels.