15 August 2002
The objection to this method is that a pump manufacturer, in order to furnish guarantees
of efficiency, must estimate all friction losses in the system.
Tide Effect. Generally, tests to determine capacity and efficiency are so
timed that the end of the test will occur when the elevation of the tide is at approximately
mean high water or mean higher high water. Although it is necessary that the pumps be
capable of dewatering docks at any tide stage, the average condition of the tide for
graving dock pumping is probably nearer half tide than high water. At locations where
tide range is considerable, it may be more reasonable to base capacity and efficiency
requirements and tests on half tide conditions.