Abstract

Skidders are vehicles used to transport timber from the felling site to the shipping site; this generally entails traversing rugged terrain. Few skidders are equipped with suspension systems or soft seats, and operators are therefore subject to shocks and high levels of vibration capable of causing back disorders.

IRSST researchers, in collaboration with an engineering team from Concordia University, performed laboratory and field trials of the vibration attenuation of several types of seats and suspension systems. Four currently available vertical-suspension seats were evaluated. Each seat was installed on skidders, and exposure to whole-body vibration in actual working conditions measured over a four-week period. Skidder operators also completed a questionnaire on the seats' performance and comfort, and possible improvements.

The SIFRA 15 LR was the only seat to satisfy all the criteria. Exposure to vertical vibration, for a daily exposure period of five hours, is 25% lower with this seat than with conventional seat with no suspension system. The seat can be installed on the most common types of skidder used in Québec forestry operations.