Vibration exposure in a forestry machine fitted with a saddle type suspension seat

Abstract

The shock and vibration isolation performance of two suspension seats with identical suspension mechanisms were tested in a forestry machine. The first seat was a standard suspension seat commonly used on forwarders; the second seat was a prototype suspension seat shaped like a saddle. The vibration exposure of two drivers using the machine on two test tracks was compared using acceleration and absorption of energy methods. On the test track designed to simulate off-road driving, there was little difference between the vibration exposures measured using the two different seats. The absorption of energy at the seat was consistently lower for the saddle seat, but absorption at the feet was higher for the saddle seat. Measurements of vibration exposure on the test track designed to generate end-stop impacts showed that there was less probability of an impact occurring for the saddle type seat than for the standard seat. It is concluded that a reduction in vibration exposure might be possible if a saddle type suspension seat is used in preference to a standard suspension seat.