MICROFICHE REFERENCE LIBFUUW - Cd3wd.com

-122which at $.20/kg, cost $6.00. However, available literature relating towater lifting report that a grown man is capable of about 0.06 - 0.08 hp(or 2000-2700 ft-lb/min) of output energy over a sustained period, i.e.,about 5 hours, not including rest periods (Allison, 1975 and Staff, 1971).Human power also variesdepending on the type of motion performed.More power can be obtained from leg motion than by the arms. During shorttime periods (lo-15 minutes), the legs can develop about 0.25 hp whilethe arms can provide only about 0.10 hp (Mengin, 1976).Severa$ adaptions and additions to basic water lifter designs havebeen utilized to also reduce energy output per each motian. The daonand counterpoise lift (see Section 3.2) with counterweights to reduceliftedloads are two examples of such designs.A recent development by Tim Journey (formerly with UNICEF ‘in Bangledesh)has produced another energy conservingdevice which could be used withseveral reciprocating water lifters. However, Journey has specificallyapplied it to the manual piston pump. An overhead, horizontal bar hase the pump connecting rod attached to one end and a pendulum to the otherend. The pendulum can simply be a vertical pole with a sand bag attachedto the bottom. For lifts between 10 and 17 ft, a horizontal push on thependu!um of about 15 to 22 lbs is needed to maintainthe pendulum swinging,which utilizes its weight to conserve the manual energy applied to it--see Allison, 1975.Drs. Sant Garg and Radhey La1 have developed a systemby which manualpower can be used to drive a centrifugal pump--a water lifter previouslyrestricted to high speed drivers. By means of a 4-bar linkage (calleda “crank and rocker mechanism”), the reciprocating motion of two men isconverted into a rotary motion. Then, a gear train of six spur gears, with