found that the vacuum could not be made to exceed 24 inches, and
during the peak, with the two turbines running, the vacuum would often
drop to 12 inches. A vacuum of 16 inches or 18 inches on the peak was
considered good.

An Investigation

Severe criticism "rained" heavily upon the engineer in charge, and
complaints were made in reference to the high oil consumption. An
investigation on the company's part followed, and the firm which
furnished the centrifugal pump and engine was next in order to receive
complaints. Repeated efforts were made to increase the speed of the
vertical engine to 285 revolutions per minute, but such a speed proved
detrimental to the engine, and a lower speed of about 225 revolutions
per minute had to be adopted.

A thorough test on the pump to ascertain its delivery at various speeds
was the next move, and a notched weir, such as is shown in the
elevation, was employed. The test was made on No. 2 cooling tower, not
shown in the sketch, and showed that barely 3000 gallons per minute were
being delivered to the cooling tower. While the firm furnishing the pump
was willing to concede that the pump might not be doing all it should,
attention was called to the fact that there might be some other
conditions in connection with the system which were responsible for the
losses. Notable among these was the hydraulic friction, and when this
feature of the case was presented, the company did not seem at all
anxious to investigate the matter further; obviously on account of
facing a possible necessity for new piping or other apparatus which
might cost something.

Approximately 34 feet was the static head of water to be pumped over No.
2 cooling tower. Pressure gages were connected to the suction,
discharge, and condenser inlet, as shown at G, G' and G'' respectively.
When No. 1 unit was operating alone the gage G showed practically zero,
indicating no vacuum in the suction pipe. Observing the same gage when
No. 2 unit was running, a vacuum as high as 2 pounds was indicated,
showing that No. 2 was drawing more than its share of cooling water from
the main A and hence the circulating pump for No. 1 was fighting for all
it received. Gage G' indicated a pressure of 21 pounds, while G''
indicated 18.5 pounds, showing a difference of 2.5 pounds pressure lost
in the S-bend. This is equivalent to a loss of head of nearly 6 feet,
0.43 pound per foot head being the constant employed. The total head
against