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[News] Whaley Bridge.



Raleigh Chopper

New member
Sep 1, 2011
12,054
Plymouth
Said if the dam breaks and the people's houses are destroyed they will be rehoused in quality accommodation, just like they did with Grenfell ???

Did he really say that?
What's he going to do rebuild the town with local stone in the traditional style or move them miles away.
Didn't he think that they must be worried enough about their houses without saying, well when they are washed away, we will find you somewhere decent to live.
Let's face it, I don't think it's going to break, the weather is better and engineers with the military are on the job.
What an opportunist prat he is, good that he has gone but he should have just visited the site and then gone to see the locals as they are out of their houses for the time being.
Surprised he didn't say that their are 5 really good food banks within 5 miles if your children go hungry.
 




Still up isn’t it?
The one in northern Sheffield didn't survive its first filling in 1864...
https://youtu.be/iVdptJeXvDY

Their depiction of the Sheffield police record suggests over 100 children died, but the true age demographic can just about be seen in this still

Screenshot_20190802-214046.png
 


Thunder Bolt

Silly old bat
i did my honours dissertation on the history of embankment dams and designed a dozen large dams several years ago. So to Answer the original question, no it should not have collapsed by now but it still could. Getting the water away from the erosion was the first critical item and then unloading the structure (dropping the water) is next. As it was designed in 19th century it may be over designed as it was empirical design as most geotechnical engineering hadn’t been fully developed so it is probably over sized. Due to failure of dams leading to deaths last century / early part of this century, all dams above a certain size have to inspected under the reservoirs act 1975, normally once a decade in detail and for a dam this size revisited every year. So this dam should be on an annual inspection and 10 year detailed review (which would have involved recalculating spillway capacity). Looking at the pictures, the spillway must have had a weakness to let water under it which then lifted rest of concrete slabs then erosion occurred.

I expect there will be several Technical review papers in the future behind the failure, explaining the why

I love the fact, that no matter what the subject is, on Nsc, there is someone who really does know what they're talking about.

Kudos to the RAF who were flying helicopters from 05.00 right through to late evening, dropping off aggregate to shore up the dam, and the emergency services working 24/7 there, no knowing if the dam would give way.
 


Baker lite

Banned
Mar 16, 2017
6,309
in my house
Said if the dam breaks and the people's houses are destroyed they will be rehoused in quality accommodation, just like they did with Grenfell ???

How many chancers will be saying “ I lived in that village and so did My wife”?


Sent from my iPad using Tapatalk
 


Leekbrookgull

Well-known member
Jul 14, 2005
16,376
Leek
On yesterday,s JV show on R2 a suggestion from a caller was 'why not if you were supplied with water from the reservoir turn on your cold water tap' thus increasing the demand for water from the water company that was drawing water from that reservoir. Sounds silly,but sometimes you might have to try something different.
 




Weststander

Well-known member
Aug 25, 2011
68,986
Withdean area
On yesterday,s JV show on R2 a suggestion from a caller was 'why not if you were supplied with water from the reservoir turn on your cold water tap' thus increasing the demand for water from the water company that was drawing water from that reservoir. Sounds silly,but sometimes you might have to try something different.

All jokey.

This reservoir supplies the adjacent canal, not domestic water supplies.
 


I love the fact, that no matter what the subject is, on Nsc, there is someone who really does know what they're talking about.
I thought that too, but was a bit surprised that no mention was made of the clay soil construction that a TV reporter mentioned. A quick search reveals that this is the obsolete practice of poodling, which I thought was the term for tarting up any breed of dog for a show....
 










Weststander

Well-known member
Aug 25, 2011
68,986
Withdean area
why would a canal need a water supply? The only way water can be lost is through evaporation, and I imagine that would be replaced by precipitation directly into the canal. We need that expert back!

Isn’t water lost due to gravity when the locks are used.

Where’s that expert?
 




banjo

GOSBTS
Oct 25, 2011
13,407
Deep south
Been given a 15 minutes window to collect what they can from their properties. More rain on the way apparently.
 


lost in london

Well-known member
Dec 10, 2003
1,833
London
O
i did my honours dissertation on the history of embankment dams and designed a dozen large dams several years ago. So to Answer the original question, no it should not have collapsed by now but it still could. Getting the water away from the erosion was the first critical item and then unloading the structure (dropping the water) is next. As it was designed in 19th century it may be over designed as it was empirical design as most geotechnical engineering hadn’t been fully developed so it is probably over sized. Due to failure of dams leading to deaths last century / early part of this century, all dams above a certain size have to inspected under the reservoirs act 1975, normally once a decade in detail and for a dam this size revisited every year. So this dam should be on an annual inspection and 10 year detailed review (which would have involved recalculating spillway capacity). Looking at the pictures, the spillway must have had a weakness to let water under it which then lifted rest of concrete slabs then erosion occurred.

I expect there will be several Technical review papers in the future behind the failure, explaining the why

Fascinating stuff, thanks
 








Doonhamer7

Well-known member
Jun 17, 2016
1,448
To answer some of the above statements.
Reservoirs are needed to keep canals full, as when gates are opened at the locks considerable amount of water is lost. The reservoirs act as the balancing amount. Most reservoirs in the uk don’t exist for water supply but include canal system, hydro power, ornate ponds, fishing, flood protection (not sure there are any tailings dam in UK - this was the one that failed in Brazil earlier this year)
Turning on you cold tap won’t work, as all water we drink has to go through a treatment works. For surface water this will be several processes (ground water may just need chlorination) including filtration, clarification, super and dechlorination. The water will then flow into the distribution system, that alone has its own complexities , valves, pumping, service reservoirs etc. Therefore the system probably will limit what can go through to your tap.
As part of the role of the inspecting and supervising engineer will be to decide on the impact of a potential failure and its impact on life and buildings. I have done dam failure flood calculations in the past, most failures don’t really impact life as they will just flood land or take out a few sheep.
Morbidly in the worst dam disaster the dam is still standing (in Italy), as the reservoir was being first filled it led to instability on the slopes of the reservoir which then had a landslide slipped into reservoir and all the water was forced out over toppling the dam and killing hundreds of people.
I had a colleague looking at the decommissioning of dams, and for some of the mega dams ( with huge reservoirs and in flows (eg Kariba on the zambezi) it may be next to impossible to empty them safely.
Anyway could write war and peace on this ....making me think maybe I should have remained in this field as it was so interesting
 


I'm surprised Trump isn't on the case, making suggestions to the RAF à la Notre Dame :)

I imagine another of those silly suggestions he might make would be to just let the water out gradually over the town, as it's only the force of the water that's the potential problem. What would you say to a numpty who suggested that, Doonhamer?
:blush:
 


LlcoolJ

Mama said knock you out.
Oct 14, 2009
12,982
Sheffield
I'm surprised Trump isn't on the case, making suggestions to the RAF à la Notre Dame :)

I imagine another of those silly suggestions he might make would be to just let the water out gradually over the town, as it's only the force of the water that's the potential problem. What would you say to a numpty who suggested that, Doonhamer?
:blush:

"I know dams folks. I've seen them, they control water. So I'm told. I'm a VERY clever guy, dams are ok. I like them. Water is ok. Next! No not you the fake news water guy, not you."
 




Arthritic Toe

Well-known member
Nov 25, 2005
2,477
Swindon
The BBC reported that the dam has been "protecting Waley Bridge for 200 years". As if the resevoir would have been there anyway and the dam was somehow doing a heroic job holding it back.
 


Kosh

'The' Yaztromo
To answer some of the above statements.
Reservoirs are needed to keep canals full, as when gates are opened at the locks considerable amount of water is lost. The reservoirs act as the balancing amount. Most reservoirs in the uk don’t exist for water supply but include canal system, hydro power, ornate ponds, fishing, flood protection (not sure there are any tailings dam in UK - this was the one that failed in Brazil earlier this year)
Turning on you cold tap won’t work, as all water we drink has to go through a treatment works. For surface water this will be several processes (ground water may just need chlorination) including filtration, clarification, super and dechlorination. The water will then flow into the distribution system, that alone has its own complexities , valves, pumping, service reservoirs etc. Therefore the system probably will limit what can go through to your tap.
As part of the role of the inspecting and supervising engineer will be to decide on the impact of a potential failure and its impact on life and buildings. I have done dam failure flood calculations in the past, most failures don’t really impact life as they will just flood land or take out a few sheep.
Morbidly in the worst dam disaster the dam is still standing (in Italy), as the reservoir was being first filled it led to instability on the slopes of the reservoir which then had a landslide slipped into reservoir and all the water was forced out over toppling the dam and killing hundreds of people.
I had a colleague looking at the decommissioning of dams, and for some of the mega dams ( with huge reservoirs and in flows (eg Kariba on the zambezi) it may be next to impossible to empty them safely.
Anyway could write war and peace on this ....making me think maybe I should have remained in this field as it was so interesting

As someone who works in the water industry - yes, your comments are spot on. I have been involved with 10 year inspections and concur with your posts in relation to everything. I'd say you're a loss to the industry tbh!!

I find the shape and design on the WB spillway and it's relationship with the river below very strange and unusual based on my experiences of similar assets designed and built circa late 1880s - 1900...

I currently work on a reservoir with a primary and secondary overflow/spillway which is perfectly designed to deal with an extreme weather event, which even in this age of unpredictable rainfall/precipitation, would be more than adequate and prevent flooding and loss of life/property.

I'd love to see/understand the rationale behind the WB design.

Interesting stuff, hopefully the worst is behind us with regard to this.

An interesting fact I can add is that dam walls travel, something that I had not grasped until I saw actual evidence of a dam wall moving (as it was designed to do) some 12-15cm since construction in the 1960s. I'm unsure if this can cause things to alter slightly with regard to an integral spillway of this design?!? and perhaps lead to a hairline weakness of sorts that only extreme overflow would reveal?
 


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