Tainter gate

The Tainter gate is a type of radial arm floodgate used in dams and canal locks to control water flow. It is named for Wisconsin structural engineer Jeremiah Burnham Tainter.cite web
title=The Tainter Gate
work=Dunn County Historical Society
url=http://discover-net.net/~dchs/history/exgate.html
accessdate=2007-03-21] .

A side view of a Tainter gate resembles a slice of pizza with the crust facing the source or upper pool of water and a triangle pointing toward the destination or lower pool. The face or skinplate of the gate takes the form of a cut cylinder. Triangular arms extend back from each end of the cylinder section and meet at a trunnion which serves as a pivot point when the gate rotates.cite web
title=Fox Point Hurricane Barrier
work=Providence RI Dept. of Public Works
url=http://www.providenceri.com/publicworks/hurricane/tainter_gates1.html
accessdate=2006-04-14]

When a Tainter gate is closed, water bears on the convex (upstream) side. When the gate is rotated, the rush of water passing under the gate helps to open and close the gate. The rounded face, long radial arms and trunnion bearings allow it to close under its own weight. Tainter gates are usually controlled from above with a chain/gearbox/electric motor assembly.

A critical factor in Tainter gate design is the amount of stress transferred from the skinplate through the radial arms and to the trunnion and the resulting friction encountered when raising or lowering the gate. Some older systems have had to be modified to mitigate frictional forces not planned for.cite web
title=Tuttle Creek Dam Spillway Tainter Gates
work=Corps of Engineers, Kansas City District
format=PDF
url=http://www.nwk.usace.army.mil/projects/tcdam/factsheets/tainter-gate-fs.pdf
month=June | year=2001
accessdate=2006-04-14]

The Tainter gate is used in water control dams and locks worldwide. The Upper Mississippi River basin alone has 321 Tainter gates, and the Columbia River basin has 195. A Tainter gate is also used to divert the flow of water to San Fernando Power Plant on the Los Angeles Aqueduct.

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