114 



Cost of i ii in pi ii u With 



I ' 



and Single 

 : MS for ISO Foot Lift. 



Acting Triplex 



The capacities of pumps, especially plunger pumps, and the sizes of 

 engines, vary with the different makes, and for that reason the sizes given 

 are not always obtainable, but sizes approximating these can be used 

 in place. 



The above cost estimates are only approximate. They are based on the 

 conditions stated above and are not applicable to all cases because of the 

 varying conditions which make the installation of nearly every pumping 

 plant a special problem. The estimates are made for gasoline engines and 

 are considerably higher than for electric motors. The first example showed 

 that with an electric plant the cost of pumping was only 60 per cent, of the 

 cost with a gasoline plant. The tabulated values show the following inter- 

 esting results: 



1st. The cost per acre of pumping is much larger for a small area than 

 for a large area. 



2nd. The cost per acre does not vary considerably with the period of 

 operation, and in some cases a plant moderately large operating for a 

 shorter period will cost less per acre than a smaller plant operating a 

 longer period. This is due to the lower fuel cost obtained with the larger 

 more efficient plant and the decreased cost of attendance for the shorter 

 period of operation which overbalance the larger fixed charges. Even 

 should the resulting cost be smaller for the smaller plant, the inconveni- 

 ence due to pumping for a long period and the extra labor in irrigation 

 may overbalance the saving in cost. 



3rd. For the lifts assumed a period of operation equal to about ten 

 twenty-four hour days during the month or one-third of the time during 

 the irrigation season seems to be preferable with the centrifugal pump. 

 With the higher price triplex plunger pumps a period of operation of one- 

 third to two thirds of the time jis preferable. 



CO-OPERATIVE PUMPING. 



The lower cost per acre for larger areas shows the advantages to be 

 gained by cooperation between small owners. By uniting and installing a 

 large plant instead of several smaller plants the cost of installation and 

 operation is very much reduced and the plant can be given more compe- 

 tent attention which relieves the orchardist and increases the life of 

 the plant. 



Where by such cooperation several hundred acres can be brought to- 

 gether, a central steam plant to generate electric power, which is trans- 

 mitted to the several electric motor pumping plants, is the most economical 

 and best solution. 



