Physiological effect of vibrations on tractor drivers under variable ploughing conditions.

The vibration conditions to which tractor operators are subjected are complex and varied with multi axis translation and rotational vibration inputs to different parts of the body. Working under such conditions may lead to human fatigue and other driving related hazards. The present research was carried out to study the operators under varying conditions of vibration while driving a tractor with and without farm equipment on different fields. Test runs were conducted in wet and dry fields to determine the levels of vibration generated at different engine speeds. On the basis of this study three levels of vibration namely 2.5, 3.5 and 5.0 m/s(2) were selected. Five subjects, all males, with no experience in the field of tractor driving participated in the study. The data were analyzed on the basis of three factor repeated measure kind of experimental design. The results showed that the main effects of farm equipment and the vibration level were statistically significant but the effect of field type was found to be statistically non-significant. The results of the study call upon the ergonomists to design and develop a tractor where the driver may be relieved of vibration induced stresses. Front loading of farm equipment is recommended for improved visibility and better working posture.