T he shaduf (sometimes spelled shadoof and sometimes referred to as a dhenkli, picottah or counterpoise-lift) is a counterbalance device to assist humans in lifting water (fig. 1). The shaduf originated along the Nile and was recorded in tomb drawings at Thebes dating from 1250 B.C. It has been used in the Middle East, Asia, and Africa. Reported here are the physical parameters, as well as energy-input and water- output characteristics of 26 of the more than 15,000 shadufs in use in the Kanem (Prefectures of Lac and Kanem) in Chad (Africa) in 1989. The purpose of this study (Mirti, 1990) was to develop information to be used in the comparison of the shaduf with other types of possible water lifting apparatus, and by agricultural development planners in understanding and projecting water supply potentials. THE SHADUF The principal structural parts of the shadufs involved in this study are illustrated in figures 2 and 3. The lever is pinned to a free-rolling axle supported by slightly concave horizontal runners, which are themselves held up by either two large, forked palm trunks or acacia tree trunks and large branches fastened together as supports. Lever counterweights are made of interlaced palm leaves filled with dried mud. The water vessel is attached to the lever by a hand-made rope. Vessel capacity was found to range from 12 to 20 L (3-5 U.S. gal) with an average size of 15 L (4 U.S. gal) and was found to consist typically of a tightly woven basket or an enamel bowl no longer fit for household use. PERFORMANCE CHARACTERISTICS OF THE SHADUF: A MANUAL W ATER-LIFTING DEVICE T. H. Mirti, W. W. Wallender, W. J. Chancellor, M. E. Grismer ABSTRACT . 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. Keywords. Irrigation, Chad, Shaduf, Shadoof, Water supply, Water-lifting devices, Manual, Human-powered, Arid climates. Article was submitted for publication in August 1998; reviewed and approved for publication by the Soil & Water Division of ASAE in February 1999. The authors are Thomas H. Mirti, Hydrologist, Suwannee River Water Management District, Live Oak, Florida, Wesley W. Wallender, ASAE Member Engineer, Professor, University of California, Hydraulic Science, Davis, Calif., William J. Chancellor, ASAE Fellow Engineer, Professor Emeritus, University of California, Biological and Agricultural Engineering, Davis, Calif., and Mark E. Grismer, Professor, University of California, Hydrologic Science, Davis, Calif. Corresponding author: Dr. Wesley Wallender, University of California, LAWR, Davis, CA 95616; voice: (530) 752-0688; fax: (530) 752-5262; e-mail: wwwallender@ucdavis.edu. Applied Engineering in Agriculture VOL. 15(3): 225-231 © 1999 American Society of Agricultural Engineers 0883-8542 / 99 / 1503-225 225 Figure 1–View of one shaduf in the fully raised position. sw 3335 ms 9/25/01 12:00 PM Page 225