TESTS OF DEAHSTAGE PUMPING PLANTS. 49 



for normal plant operations and does not include the 25 per cent 

 allowance for starting and lubricating oils. The accuracy of -the 

 work is limited by the amount of data available. 



It will be noted that curve II does not pass through the point 

 plotted for Jefferson drainage district No. 3 nor through point for 

 subdistrict Xo. 1, Gueydan drainage district, but is drawn between 

 them to give probable results for an average plant of this type. It 

 must be remembered that the test of the former plant showed greatly 

 unbalanced quantities passing through the two suction pipes. The 

 engines are rather large for the pumps, and this doubtless has a 

 material effect on economy. On the other hand, the Gueydan 

 pumps are volute pumps of much more elaborate design than the 

 drainage pumps of Jefferson drainage district No. 3. The pumps 

 were large and the velocities of water through them comparatively 

 slow; all these factors made for lower fuel rate. 



Figure 6 shows the cost per year of pumping 29 acre-inches against 

 various lifts, as obtained from the curves of figure .5. For the 

 average drainage proposition discussed in this report the lift for 

 the first two or three years is approximately 3 feet; later, when a 

 part of the humus disappears and deeper drainage is desired, the 

 lift is increased to 5 feet or more. The general range of lift was 

 from 2 to 8 feet. 



In all the tests recorded oil was used as fuel. In order to make a 

 comparison of cost it is necessary to consider the kind of oil used in 

 the different plants. The steam plants and the Diesel-engine plant 

 Xo. 20 (fig. 5), either used or could use Mexican crude or some low 

 grade of fuel oil. Prices of fuel oil have fluctuated considerably 

 during the last seven years. During 1919 and 1920 the price of oil 

 delivered ;it Xcw Orleans has ranged from about 75 cents to $3.50 

 per hand. The prices of distillates and kerosene have shown 

 Variations that make it impossible to arrive at a probable cost for 

 the future because of the great instability of prices. 



The average price of the lower grade of fuel oil delivered at the 

 pumping plant for the years 1912-1917 was about $1.10 per barrel 

 <«f 12 gallons. For dot-bulb engines of the semi-Diesel type a higher 

 grade of crude oil is required. The price for (his oil delivered at 

 pumping plants for the same period panged from $1.40 to $1.80, 

 with the ;i \ erage about si .60. 



Some internal-combustion engines, Buch as those in plants Xo. 

 8 :iml Xo. id. are supposed to use a distillate of low grade, costing 



ah fill the -;Mii<- as the fuel oil used iii the semi-Diesel engines. In 



-one' instances distillate baa been mixed with kerosene to make ;i 

 more jatisfactory fuel, riant- Nbs. 8 and lo may he operated in 

 i ! n- wav. Planl Xo. !i uses kerosene. The cost of distillate deli's 



