Abstract

The walk-behind control of single-axle tractors imposes a great workload on the operators which increases muscular fatigue. Experienced operators were involved during field experiments to investigate and establish the magnitudes of hand-transmitted vibration experienced by single-axle tractor operators with and without vibration reduction isolators during tillage operation. The results indicated that the magnitudes of vibration total values were 5.694 m/s2 at approximately 1500 rpm on stationary mode, 6.972 and 7.985 m/s2 at 1.5 and 2.7 km/h respectively during tillage operation. The use of rubber with metallic washers as vibration reduction isolators result in a significant reduction in magnitudes of vibration total values to 3.656 m/s2 in stationary mode, 4.365 and 4.958 m/s2 at 1.5 and 2.7 km/h respectively during tillage operation. The National standard TZS 1471 (2018) and ISO 5349-2 (2001) warns that, the exposure to higher magnitudes of vibration presumably carries increased health risk towards vibration-induced disorders and other occupational hazards associated with body fatigue. These call for collaborative efforts among design engineers, researchers, and the research and development organizations to further study the human-machine interaction behaviour of single-axle tractors and human engineering data to ensure human safety, satisfaction of the single-axle tractor operators and ensure safe and healthy working environments.

Key words: Single-axle tractor, hand transmitted vibration, vibration reduction isolators.