overshot gate in stock

Waterman Tilting Weir (Overshot) Gates are an overflow-type gate used to control levels in canals, basins and other agricultural, municipal and industrial applications.

The basic gate design uses a rectangular panel mild steel panel that is mounted to a piano hinge at the forward bottom edge of the gate leaf.    This leaf is raised and lowered using a cable drum hoist to control the upstream water level.

Overshot gates (also known as pivoting weir gates) are used to control upstream water levels. Versatility, efficiency, and safety are the primary reasons the Fresno Overshot Gate is the method of choice for municipal, agricultural, and industrial canal water control.

I am using a sluice gate with an ogee inline structure. I have never worked directly with an ogee weir and HEC-RAS asks for inputs like "Spillway approach height", and "Design energy head". I am not quite sure what this is in reference too. Is there a post or reference manual somewhere that explains this more in depth?

Chris, we have a model with these sorts of overshot gates, that run the entire length of a dam. We are modeling these gates as initially closed, and as a large hydrograph comes through the gates fail and are fully open. Then during the same hydrograph we are trying to model a breach of the inline structure. However, the results of the "with breach" case match the results of the "no breach" case exactly. It"s as though RAS is treating the breach opening like it"s not there, or that water cannot flow through it. Is this true for RAS, that it does not recognize a breach that is below an overshot gate? I ask because if we take the gate out and just pretend that they were open the whole time so that there is only the inline structure, the resulting hydrograph shows the impact of the breach. Thanks Chris.

Cory- That is intriguing. I"ve never run into that before, but I can see how there might be some unintentional conflict in the code with breaching under a gate. Can you send me your model using the debug report (http://hecrasmodel.blogspot.com/2008/12/hec-ras-debug-report.html) and I"ll see if I can see what is going on? Thanks-cgoodell@westconsultants.com

I was wondering why sometimes different kinds of gates( I mean overflow and underflow gates) is being used in the same check structures. I have seen many checks with five gates with 2 under flow gates on side and 3 overflow in middle. what is the purpose of such a design? Furthermore In time of operation do all gates open together or not?

Mike, honestly I don"t know the typical purposes of such gates. I have seen them used for fish passage, where the multiple outlet options give fish a preference for how they want to pass. Otherwise, not sure…

Hi, I am a relatively new user. I am confused about a simple thing. I want to model a overflow structure with around 15 gate openings. Do I need to draw a solid embankment extending from the starting to the ending of the gates using the weir/embankment option under inline structure before defining the gates? Or do I need to keep opening in the embankment?

I like to model radial gates and sluice gates with broad crested weir. Is it possible to use broad crested weir with radial gates. Even though in the selection dialogue box it is there, I doubt that, as all the explanations related with radial gates are drawn with ogee spillway.

Hi Chris, thanks for pointing out this option! One thing is not clear to my however: How can I control the gate"s Crest Level (as opposed to the Gate Opening Height)? Is the only way to do this by implementing a closed top overflow gate and applying negative opening heights to it so as to keep the gates closed at all times and only allow for flowing over the gate"s top? Or is there an option using an Open Air gate as well? As far as I can tell the Unsteady Data Editor only provides a possibility to enter a timeseries for the Gate Opening Height; not for the Gate Crest Level.

Siebe, with overflow gates, the gate opening value you enter in the unsteady boundary condition is measured from the maximum gate top elevation (gate fully up) to the actual gate top elevation. For example, you set the Height in the overflow gate geometry properties to 4 meters. And the gate invert elevation is 0 meters. If you put in a gate opening height of 1 meter in the unsteady flow boundary condition table, the gate will be open so that the crest of the gate is at elevation 3 meters.

Thanks Chris! It"s rather embarrassing how long it took me to understand the concept :"(. In The Netherlands we simple don"t have any gates that move downwards in order to open up. All of our gates are opened by pulling them up, so it took a little mind bending to understand it.

Since RAS doesn"t have a double door type gate built in, you have to do some sort of workaround. If you can accept a little bit of error during the opening/closing sequence, you could just pick one of the available gates and try to make it work that way. This might be okay if the gate opens/closes relatively quickly. Or, you could develop your own rating curve and model the gate with user-defined curves. The problem with this is that user-defined curves are tailwater independant, and based on your description and photos, that is not the case for your gate. That leaves you with writing rule scripts. It"s sort of complicated, but you could develop rating curve tables for a range of tailwaters, and use rules to pick from the correct table, based on the computed tailwater. That"s probably what I would do if I needed it to be super accurate. Otherwise, I"d probably just go with one of the built-in gates available in RAS.

sir i am not getting that which height is called as invert height/level of gate. radial gate discharge coefficient and trunnion height of gate please help me out

That is a great article. I am facing a problem and interested in your opinion. I have to model a two boarded gate. My problem is that this type of gate allow an adjustable overflow height and can be opened from the bottom in the same time as well, or lower both board to a minimum overflow height, or raise both board to make a huge opening. Is this even possible? i am thinking on putting a normal gate and an overflow gate right on top of each other but not sure program van handle it.

I like your idea for a solution. I think you can put one on top of the other as different gate groups. However, if the program doesn’t like that, you can always put one next to the other. Good luck. Let me know how it goes.

The only issue i encountered so far is with closed top overflow gates i receive a warning about overlapping gates but it can be ignored and works fine. With open air solution there is no warning.

Mueller refers to one or more of Mueller Water Products, Inc., a Delaware corporation ("MWP"), and its subsidiaries. MWP and each of subsidiaries are legally separate and independent entities when providing products and services. MWP does not provide products or services to third parties. MWP and each of its subsidiaries are liable only for their own acts and omissions and not those of each other. Mueller brands include Mueller®, Echologics®, Hydro Gate®, Hydro-Guard®, HYMAX®, i2O®, Jones®, Krausz®, Mi.Net®, Milliken®, Pratt®, Pratt Industrial®, Sentryx™, Singer®, and U.S. Pipe Valve & Hydrant. Please see muellerwp.com/brands to learn more.

The series 6400 slide gate is available in sizes from 8-48 inches and is designed for use in irrigation canal turn outs, reservoirs, drainage systems, dams,

York Civil Pty Ltd engaged AWMA to custom design vertical water control gates, fishway gates and hydraulic actuation systems for SA Water’s Pipeclay and Slaney Weirs.

Five large AWMA Fixed Base Overshot (decant) gateswere developed to simulate overshot flow patterns of the existing stoplogs, whilst Segmented Stopboards were supplied for the new environmental fishways.

The largest water control gate provides a clear water opening of 5800mm, has a gate leaf height over 2m high and is subject to 10tn of water pressure plus environmental debris loading.

The overshot gate leaves were manufactured from marine grade aluminium with grade 316 stainless steel embedded frames and stainless steel dual cylinder actuation systems.

This project is subject to isolation issues with the Slaney regulator accessible only via boat. SA Water will operate these gates using AWMA’s petrol driven Hydraulic Power Pack, designed to allow easy operation of remote sites. The portable device will be quick coupled to the control manifold via hydraulic hosing for ‘plug and play’ operation. Additionally, this option limits the asset investment permanently required on-site, reducing the risks of vandalism and system damage.

Marine grade aluminium segmented stopboards and AWMA lifting ladders were supplied for the fishway gates. Design features include overshot flows with low velocities for safe fish passage.

A penstock is a water control gate or structure that controls flow. Penstocks may also be known as Sluice gates, Slide gates or Stopgates. Penstocks are designed for flow regulation, diversion, level control or isolation.

AWMA is a renown penstock supplier, manufacturing high quality, high performance water control gates for all industries. Aluminium and stainless steel water management products are supplied as standard designs or tailor made to meet specific site requirements. Technical Sales Managers located in Australia and New Zealand are available for early contractor involvement and site inspections as required.

Mueller refers to one or more of Mueller Water Products, Inc., a Delaware corporation ("MWP"), and its subsidiaries. MWP and each of subsidiaries are legally separate and independent entities when providing products and services. MWP does not provide products or services to third parties. MWP and each of its subsidiaries are liable only for their own acts and omissions and not those of each other. Mueller brands include Mueller®, Echologics®, Hydro Gate®, Hydro-Guard®, HYMAX®, i2O®, Jones®, Krausz®, Mi.Net®, Milliken®, Pratt®, Pratt Industrial®, Sentryx™, Singer®, and U.S. Pipe Valve & Hydrant. Please see muellerwp.com/brands to learn more.