MICROFICHE REFERENCE LIBFUUW - Cd3wd.com

3.2.1.1 Bucket/BagUtilizing nothing more than a container such as a bag (e.g., ofskin or plastic) or solid bucket, a man can raise water to the head andquantity limits of his reach and strength. As illustrated in Figure 2.3,the performance of this simple water lifting act can be presented asmerely the buckets per minute (Q) which can be lifted between twoelevations 0-0 - Or by multiplying Q by the volume of water dischargedper bucket, these results can be recorded in more conventional dischargeunits. One source (Weisback and Herrmann, 1897) reports that using a0.35 ft3 (10 liter) bucket, one man can lift about 15 buckets per minuteor 300 cfh to a height of 3.3 ft. This performance requires roughly 1100ft-lbs of work per minute, which is 0.033 WHP.When the required lift exceeds the reach of a single person, he hasthree alternatives, or combinations thereof, to increase his lift; (a)taking more time to carry the container up an incline (usually using ayoke to carry a pair of buckets) , (b) using two or more people in seriesalong which the bucket(s) can be passes, or (c) utilizing a pole or rope(chain, etc.) attached to the bucket. Alternative (a) is a continuationof Figure 2.3, sacrificing discharge to increase lift, while (b) requiresadditional work input. Alternative (c) is the beginning of anothercategory of water lifting devices.3.2,1.2 Bucket and RopeUtilizing only a rope or pole (often called a cistern pole andhaving a hook at one end on which to hand a bucket--see Ewbank, 1876, p.57) to lower a container into a water source, the lift can be significantlyincreased. However, since the strength of the human lifter still limitsthe capacity of the container, as more time is consumed lowering and