Ergonomics of “Haramba” Wheat Thresher

Studies were carried out on high capacity “Haramba” wheat thresher to study the effect of independent variables i.e. three pairs (feeder and supplier) of subjects; three levels of height of feeding chute w.r.t platform (97.7 cm, 82.5 cm and 67.3 cm); three levels of feed rates (15 q/h, 20q/h and 25 q/h) on the heart rate of subjects. Heart rate of all subjects (feeder and supplier) increased with increase in feed rate at all heights of feeding chute w.r.t platform. Heart rate response of all subjects (feeder and supplier) was different at different heights of feeding chute w.r.t platform corresponding to all feed rates as their different heights altered the body posture. Optimum height of feeding chute w.r.t. platform was found in term of elbow rest height of subject w.r.t feeding chute and it was 28 cm. Work load was more in case of supplying the crop than feeding the crop into thresher. All the feeders were under moderate work load for all feed rates at their suitable height of feeding chute w.r.t platform in the studies range. Similarly in case of suppliers, work load was moderate for feed rate upto 20 q/h but was heavy for feed rate of 25 q/h. An additional supplier can be engaged for supplying the crop which will reduce the heavy work load on a single supplier. Studies indicated that a single feeder and two suppliers will be able to match the throughput capacity (25 q/h) of thresher or even higher (30 q/h) as claimed by the manufacturer if the platform was made adjustable to accommodate the subjects of different heights.