Talk:Tainter gate

message: This article was origanially just copied+pasted from the website listed. More than one source of information should be found to add to a more comprehensive article. 
WikiDon 09:18, 19 September 2005 (UTC)
replies: text: You were right.  Consider it done.  There's other interesting information out there too, like Tainter gates in Europe and elsewhere, that could be incorporated into the article. -- Muffuletta 22:10, 14 April 2006 (UTC)
replies: text: I know this isn't the most active article, but if anyone's interested, the U.S. Army Corps' of Engineers' "EM 1110-2-2702: Design of Spillway Tainter Gates" https://planning.erdc.dren.mil/toolbox/library/EMs/em1110.2.2702.pdf contains essentially the sum of all collected tainter gate engineering knowledge in the United States. It's a bit lacking as a engineering reference, but it contains a wealth of knowledge compared to this article to date. EngiBear91 (talk) 21:17, 2 August 2020 (UTC)
thread_title: Cleanup

message: If I understand it's construction correctly (not being a Londoner, I've never looked in detail) this uses "Tainter" gates, but of the "over flow" not "under flow" design - in contrast to the examples presented from (IIRC) American sources. If that diagnosis is correct, then discussing it would help address the concerns flagged by the warning template. AKarley (talk) 11:34, 24 March 2024 (UTC)
thread_title: London [Tidal] Barrage

message: Tainter Gate, is not the Tainter product, is a segment gate, the first known was in Paris (in 1853) years before Tainter created the american one (I wrote it in Tainter article).
The name must be changed too. It is a segment gate, a type of radial gate, and it is NOT a Tainter invention, so that is the American name of an older product.  —Preceding unsigned comment added by 62.245.179.18 (talk) 11:46, 26 November 2010 (UTC)
replies: text: Hm. Interesting point. The question is, though: did Tainter derive his work from the French process, or produce it independently? At this point, I guess there's no way to know. DS (talk) 13:56, 26 November 2010 (UTC)
replies: text:  AIUI, it's Tainter's invention. His innovation was to make it the first truly radial gate, not just a segment gate. Andy Dingley (talk) 22:23, 23 June 2016 (UTC)
thread_title:  Tainter Gate origin and name 

message: It's a common quote that, "the rush of water passing under the gate helps to open and close the gate". How does this work?  How do the forces assist in both directions?
AFAICS, this is untrue. What the radial gate achieves instead, unlike earlier segment gates, is that the water forces have no effect on the gate. This means that the operating mechanism merely has to move the gate's own weight, never act against the (potentially far greater) water forces. Andy Dingley (talk) 22:25, 23 June 2016 (UTC)
replies: text: It is incorrect to say that the water forces have no effect on operation of the gate. It is more technically precise to say that the hydrostatic force on the gate does not directly resist its actuation. However, the hydrostatic force still indirectly resists actuation via trunnion pin friction. A greater total hydrostatic force corresponds to a higher normal force on the trunnion pins (the pins about which the movable portion of the gate rotates), which results in a higher frictional force between the trunnion pins and their bushings. https://planning.erdc.dren.mil/toolbox/library/EMs/em1110.2.2702.pdf This friction resists gate actuation in either direction, although the moment arm is relatively small and pins are lubricated to minimize friction. However, this phenomenon is infamous for having contributed to the catastrophic failure of a gate at Folsom Dam in the United States because the steel struts in the end frames of the gate weren't designed for the bending induced by this frictional reaction to the hoist force. With that being said, the forces associated with flowing water are dynamic and are separate from the hydrostatic pressure, so the force of water flowing under (or, in the case of "submergible" gates, over) does technically have an effect. I'm fairly certain the the effect of water rushing under the gate would work to close the gate, but since the upstream surface of the gate is relatively smooth, the effect is negligible. There is a similar structure, the reverse tainter valve, that does behave in way that allows flowing water to "help" with both opening and closing, but through different parts of its range of motion. https://www.publications.usace.army.mil/Portals/76/Users/182/86/2486/EM_1110-2-1610.pdf Reverse tainter valves work using the same principle as tainter gates, but they are typically used in lock culverts, where they are fully-submerged in a closed tunnel and are oriented with the axis of rotation on the high-pressure (upstream) side of the damming surface, rather than the downstream side like a tainter gate. This is because the traditional orientation tends to suck air into the culvert through the vertical shaft to the surface where the valve resides. Since all of the structural elements of the valve are upstream of the damming surface, there are plenty of projections to get pulled or pushed on by flowing water, and the force can be significant. When a valve is near the closed position, the water rushing underneath tends to pull down on the valve and suck it shut, making it harder to open. However, at some point in its range of motion, the valve crosses an equilibrium point. As the valve nears the open position, the water tends to push it up and out of the way so that a clear path is provided for the unrestricted flow of water. This is in addition to the regular buoyancy force on the submerged static structure. As a result, the force required to move a reverse tainter valve from 90% open to 100% open is always significantly higher for a dry valve than a submerged valve in operation, as far as I know. The "sucking" hydrodynamic forces are typically less significant and might not even be enough to cancel out buoyancy. I'm not entirely certain. Anyway, perhaps that is the origin of the "both directions" quote? EngiBear91 (talk) 21:10, 2 August 2020 (UTC)
thread_title:  Water forces on opening and closing? 

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