PERFORMANCE CHARACTERISTICS OF THE SHADUF: A MANUAL WATER-LIFTING DEVICE

The shaduf is a traditional device to assist human beings in lifting water 1 to 6 m (3-20 ft), by minimizing and distributing (over time and among various muscle systems) the forces that need be applied by the operator. This study reports on both static and videotaped dynamic field measurements with twenty-six typical shadufs in Chad. System outputs, with lifts ranging from 1.8 to 6.2 m (5.9-20.3 ft), were 0.65 to 2.18 L/s (10.3-34.6 U.S. gallons/min) resulting in water-lifting power levels of 26.7 to 60.1 W (0.036-0.081 hp). Efficiencies found were on the order of 60%. Efficiency differences between operators were found, and points of operator technique associated with improved efficiencies were identified.