TESTS OF DRAINAGE PUMPING PLANTS. 19 
TEST OF PUMPING PLANT IN SUBDISTRICT NO. 3, LAFOURCHE DRAINAGE DISTRICT 
NO. 12. 
DESCRIPTION OF PLANT. 
This plant consisted of duplicate units, each having a 30-inch 
Lawrence double-suction centrifugal pump driven by a 14 by 16 inch 
Lawrence vertical slide-valve engine. The suction openings on the 
pumps are 24 inches in diameter. The intake and discharge pipes 
have been tapered and enlarged so that the area of the intake is 2.9 
and the area of the discharge 1.8 times the area of the discharge 
nozzle of the pump. The pumps were direct connected to the engines 
by flexible couplings. The exhaust of the engines was conducted 
through a common pipe to a water heater and then discharged into 
the air. Steam was generated by two return tubular boilers of 
100 boiler horsepower each. The boilers were in a brick setting 
covered with asbestos. The fuel used was Mexican crude oil. Steam 
was used to atomize the oil in the furnaces and to run the usual oil 
and boiler feed pumps. The machinery was housed in a corrugated- 
iron building. The average lift was probably less than 3 feet and 
the maximum lift about 7 feet. The level of the water on the dis- 
charge side varied about 2 feet. The area drained is 2,260 acres. 
METHOD OF CONDUCTING THE TEST. 
It was necessary to siphon considerable water into the district 
the day before the test in order to have enough water to make a test 
of both units. As a result the lift was low at first, but rapidly 
increased to 4 feet at the time of the last reading. A five-hour test 
was made on unit No. 2, but it was necessary to stop the test of 
No. 1 after four hours to prevent the debris which had collected 
around the suction screen from breaking the screen. At noon it 
was necessary also to shut down one boiler, as the parts of one of the 
valves in the boiler feed line became detached from the valve stem 
and jammed so that no water could be pumped into the boiler. 
By forcing the remaining boiler both pumps were run until the 
necessary adjustments could be made, although the steam pressure 
dropped. 
The pumps were operated at such speed that they slightly exceeded 
their rated capacity during the earlier readings. Toward the last, 
especially after the steam pressure dropped, they were running 
somewhat under their rated capacity. The discharge of the pumps 
was measured by means of a Pitot tube in each discharge pipe at 
distances of about 12 feet from the pump. The first reading taken 
on unit No. 2 was inaccurate as to quantity pumped, as the velocity 
of the water was too great to be measured with the Pitot tube. 
Gages set in the still water in the suction and discharge canals 
were read to obtain the actual lift. This lift was used in computing 
