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Whaley Bridge Evacuated


furnessvale

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6 minutes ago, mayalld said:

It is always POSSIBLE to provide additional spillway capacity other that over the weir crest, but probably considered prohibitively expensive in the 1970s.

 

 

I'm curious where else you think it could have been provided, since it necessarily has to be somwhere where the water which flows over the weir crest can then flow downhill to the river course below the dam.  And all working within the constraints of land ownership, planning constraints, environmental impacts etc as well as cost.

 

7 minutes ago, mayalld said:

 

Protecting the dam against overtopping by allowing it to overtop with a protective surface is playing with fire.

Maybe, but also pretty standard practice.

 

11 minutes ago, mayalld said:

 

It will be interesting to see what they do to repair.

 

My guess is they will reinstate the downstream slope protection which has failed. They might also square up the side wall so that there isn't the concentration of water that results from the existing angled wall.  

 

A further analysis of the latest climatic data might result in a decision to further increase the spillway length, or to reduce the normal maximum retained water level to provide additional buffer capacity for extreme rainfall. The latter would reduce the day to day capacity of the reservoir and lead to more restrictions on lock use in dry years.

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2 minutes ago, David Mack said:

 

I'm curious where else you think it could have been provided, since it necessarily has to be somwhere where the water which flows over the weir crest can then flow downhill to the river course below the dam.  And all working within the constraints of land ownership, planning constraints, environmental impacts etc as well as cost.

 

Maybe, but also pretty standard practice.

 

 

My guess is they will reinstate the downstream slope protection which has failed. They might also square up the side wall so that there isn't the concentration of water that results from the existing angled wall.  

 

A further analysis of the latest climatic data might result in a decision to further increase the spillway length, or to reduce the normal maximum retained water level to provide additional buffer capacity for extreme rainfall. The latter would reduce the day to day capacity of the reservoir and lead to more restrictions on lock use in dry years.

Which of course will be at the bottom of the list of pririties.

 

I can see other possibilities.

 

1.  Minor repairs to the dam and run the reservoir in future at much reduced capacity.

 

2.  Proper dredging of other reservoirs (Combs, Sutton) to replace the lost capacity.

 

George

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8 minutes ago, David Mack said:

 

I'm curious where else you think it could have been provided, since it necessarily has to be somwhere where the water which flows over the weir crest can then flow downhill to the river course below the dam.  And all working within the constraints of land ownership, planning constraints, environmental impacts etc as well as cost.

 

 

That is what I said!

 

Doing it well would have involved major engineering to expand the existing side spillway, which would have cost megabucks

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4 hours ago, Jerra said:

a Civil Engineer (funny how none claim to be uncivil engineers)

In that documentary on BBC1 Canals: The Making of Britain, Liz McIvor pointed out that before Brindley, engineers were invariably military, so the new breed were “civilian engineers”, shortened to civil.

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59 minutes ago, Dustin Wright said:

No, he did not say that at all.

It would be helpful if you could explain what he did say?

59 minutes ago, Dustin Wright said:

Honestly.  You really believe that to be the case. Sounds like the comments from someone who retired many years ago. 

Are you saying you know it not to be true? Which bits? or all of it?

 

”sounds like” is neither one thing nor the other.

 

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43 minutes ago, Detling said:

I'm sure they do, but do they know how much water is lost through leakage of the locks and seepage/leakage if the canal.

I imagine they have empirical data over the years, which will be fairly consistent. Of course, loss through leakage is dependent on water table level - there are some (relatively leaky) canals where during spells of high water table, receive an inflow.

 

Also don't forget that the dam walls are angled, with respect to emptying rate. At a given flowrate, it takes less time to go from (eg) 50% to 40% by depth, than it does 60% to 50% if pumps are being used.

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Julie Sharman on a itv tweet 

 

Canal & River trust: "A full redesign and reconstruction is anticipated"

 

Engineers need to view the damage to the wall before a decision will then be able to be made with regards to people re-entering #WhaleyBridge

 

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2 hours ago, mayalld said:

It will be interesting to see what they do to repair.

 

It would be even more interesting to see them stress test it. 

 

I suspect they can't, and will have rely on, um... good design. 

 

 

 

 

 

Edited by Mike the Boilerman
Duplicate post bug strikes again.
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2 hours ago, Richard10002 said:

It would be helpful if you could explain what he did say?

Are you saying you know it not to be true? Which bits? or all of it?

 

”sounds like” is neither one thing nor the other.

 

I've watched it - and to be honest, if people are commenting without watching it, well, it kinda sums up this thread. 

 

Emma wanted him to say funding was short and was trying to fish a sensational angle, like she always does.  The irony being of all the structures under CART - reservoirs are arguably the most protected and pretty much ring fenced.  There is no way to delay or ignore any task for a reservoir in favour of a TV advert or a signage programme.   Personally, i think he did well in the face of a populous who want to blame someone, anyone for a freak set of conditions.

 

The fact there are no deaths, that an evacuation was completed and the fact that a multi agency groups came together to fix a problem is being ignored.  Alert systems did work.  

 

The only people qualified to comment on cause are those with engineering degrees and experience in structure design / fracture mechanics.  Because if you don't, well, you're waffling about things you don't understand truly.

 

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47 minutes ago, Dustin Wright said:

The only people qualified to comment on cause are those with engineering degrees and experience in structure design / fracture mechanics.  Because if you don't, well, you're waffling about things you don't understand truly.

 

Well if you can't waffle on about stuff you don't understand and ask questions to advance your understanding on an internet forum, where on earth can you? 

 

I guess if you ran the forum, no-one would be allowed to comment on anything unless they had a degree in the subject being discussed. 

 

 

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1 hour ago, Dustin Wright said:

I've watched it - and to be honest, if people are commenting without watching it, well, it kinda sums up this thread. 

 

Emma wanted him to say funding was short and was trying to fish a sensational angle, like she always does.  The irony being of all the structures under CART - reservoirs are arguably the most protected and pretty much ring fenced.  There is no way to delay or ignore any task for a reservoir in favour of a TV advert or a signage programme.   Personally, i think he did well in the face of a populous who want to blame someone, anyone for a freak set of conditions.

 

The fact there are no deaths, that an evacuation was completed and the fact that a multi agency groups came together to fix a problem is being ignored.  Alert systems did work.  

 

The only people qualified to comment on cause are those with engineering degrees and experience in structure design / fracture mechanics.  Because if you don't, well, you're waffling about things you don't understand truly.

 

It does not take a degree to know from experience that when weeds and trees start to sprout up between the concrete slabs on your drive that over time the slab will tilt because the soil under it has been washed away.  That is not waffle that is proven fact as far as I am concerned. Likewise I look forward to your explanation as to why weed infested spill ways like the one at the side of that dam do not provide any restriction or impediment to water flow. I would have thought any projection into a water flow will cause turbulet flow rather than laminar flow.

 

Then we come to CaRT's record of apparently not responding when warned about developing problems until thee is a major failure like the Middlewich arm. There is some suggestion the same applied to the Llangollen canal as well. In my view your assertion seem more about stifling discussion and just maybe showing CaRT's maintenance up for what it is than being constructive.

 

Edited to add: with only three posts and two of those related to this topic would it be reasonable to conclude you just might work for or on behalf of Ca|RT?

Edited by Tony Brooks
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16 minutes ago, Mike the Boilerman said:

 

Well if you can't waffle on about stuff you don't understand and ask questions to advance your understanding on an internet forum, where on earth can you? 

 

I guess if you ran the forum, no-one would be allowed to comment on anything unless they had a degree in the subject being discussed. 

 

 

My last job involved investigating and re educating nurses who had made serious clinical errors. 

All had ‘nursing degrees’. Some of the mistakes were hair raising.

A degree is a ticket not a certificate of competency.

Edited by roland elsdon
Error
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2 minutes ago, Tony Brooks said:

I would have thought any projection into a water flow will cause turbulet flow rather than laminar flow.

 

Actually Tony, if I remember my fluid dynamics from college correctly, turbulent flow is lower resistance than laminar.

 

In fact if you look at the photos/videos there are pairs of concrete nibs set all over into the spillway, presumably to break up laminar flow. 

 

 

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1 minute ago, roland elsdon said:

My last job involved investigating and re educating nurses who had made serious clinical errors. 

All had ‘nursing degrees’. Some of the mistakes were hair raising.

A degree is a ticket not a certificate if competency.

As my wife's cousin who worked his way up from the shop floor used to say "a degree provides highly educated idiots

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1 minute ago, Mike the Boilerman said:

 

Actually Tony, if I remember my fluid dynamics from college correctly, turbulent flow is lower resistance than laminar.

 

In fact if you look at the photos/videos there are pairs of concrete nibs set all over into the spillway, presumably to break up laminar flow. 

 

 

I know about those nibs, many dams have them and some are far more pronounced than at that one. I an sure that in our power hydraulics courses we needed to stress the need to keep bends gentle so as not to induce turbulent flow but that may have been due to turbulent flow producing more heat but if so that suggest the flow rate would be affected.

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Just now, Tony Brooks said:

I know about those nibs, many dams have them and some are far more pronounced than at that one. I an sure that in our power hydraulics courses we needed to stress the need to keep bends gentle so as not to induce turbulent flow but that may have been due to turbulent flow producing more heat but if so that suggest the flow rate would be affected.

 

Not having a degree in the subject, I'm not allowed to discuss it :giggles::giggles::giggles:

 

 

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17 minutes ago, Tony Brooks said:

It does not take a degree to know from experience that when weeds and trees start to sprout up between the concrete slabs on your drive that over time the slab will tilt because the soil under it has been washed away.  That is not waffle that is proven fact as far as I am concerned. Likewise I look forward to your explanation as to why weed infested spill ways like the one at the side of that dam do not provide any restriction or impediment to water flow. I would have thought any projection into a water flow will cause turbulet flow rather than laminar flow.

 

Then we come to CaRT's record of apparently not responding when warned about developing problems until thee is a major failure like the Middlewich arm. There is some suggestion the same applied to the Llangollen canal as well. In my view your assertion seem more about stifling discussion and just maybe showing CaRT's maintenance up for what it is than being constructive.

 

Edited to add: with only three posts and two of those related to this topic would it be reasonable to conclude you just might work for or on behalf of Ca|RT?

And the breach on the Leeds and Liverpool (last year i think) where the farmer had been telling CRT about water coming into his field from the canal embankment...

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Just now, Dave123 said:

And the breach on the Leeds and Liverpool (last year i think) where the farmer had been telling CRT about water coming into his field from the canal embankment...

and so it goes on but it appears only degree holders who know about dams should be allowed to comment CaRT's maintenance procedures.

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20 minutes ago, roland elsdon said:

My last job involved investigating and re educating nurses who had made serious clinical errors. 

All had ‘nursing degrees’. Some of the mistakes were hair raising.

A degree is a ticket not a certificate of competency.

 

Indeed, one of the roles of my last job was to check and approve the electrical designs submitted by the design consultants, who used recently qualified graduates to keep their costs down.

 

Whilst they were undoubtedly very clever, their lack of experience, resulting in potentially dangerous or unreliable designs was breathtaking.

 

After 40 odd years working your way up in in any industry you gain an awful lot of experience.

Edited by cuthound
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15 minutes ago, Tony Brooks said:

It does not take a degree to know from experience that when weeds and trees start to sprout up between the concrete slabs on your drive that over time the slab will tilt because the soil under it has been washed away.  That is not waffle that is proven fact as far as I am concerned. Likewise I look forward to your explanation as to why weed infested spill ways like the one at the side of that dam do not provide any restriction or impediment to water flow. I would have thought any projection into a water flow will cause turbulet flow rather than laminar flow.

 

Then we come to CaRT's record of apparently not responding when warned about developing problems until thee is a major failure like the Middlewich arm. There is some suggestion the same applied to the Llangollen canal as well. In my view your assertion seem more about stifling discussion and just maybe showing CaRT's maintenance up for what it is than being constructive.

 

Edited to add: with only three posts and two of those related to this topic would it be reasonable to conclude you just might work for or on behalf of Ca|RT?

Whilst one hesitates to quote from the press, because we all know how accurate they often are, could I suggest

 

https://www.bbc.co.uk/news/uk-england-derbyshire-49220650

 

as being worth a read.

 

the fact that reservoirs are inspected by a panel engineer has been mentioned several times, and there really aren't many of them. You can download the full list of qualified people, which amounts to 30.

 

In amongst the quotes from various Dam experts, we have a quote from a panel engineer (one assumes NOT the one who did the inspection), who says of the pictures;

 

"As an All Reservoirs Panel Engineer I would say that there is nothing in the photos that would cause me concern, and nothing that would indicate that the dam is not being maintained properly in general"

 

Make of that what you will....

 

 

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47 minutes ago, Tony Brooks said:

It does not take a degree to know from experience that when weeds and trees start to sprout up between the concrete slabs on your drive that over time the slab will tilt because the soil under it has been washed away.  That is not waffle that is proven fact as far as I am concerned. Likewise I look forward to your explanation as to why weed infested spill ways like the one at the side of that dam do not provide any restriction or impediment to water flow. I would have thought any projection into a water flow will cause turbulet flow rather than laminar flow.

 

Then we come to CaRT's record of apparently not responding when warned about developing problems until thee is a major failure like the Middlewich arm. There is some suggestion the same applied to the Llangollen canal as well. In my view your assertion seem more about stifling discussion and just maybe showing CaRT's maintenance up for what it is than being constructive.

 

Edited to add: with only three posts and two of those related to this topic would it be reasonable to conclude you just might work for or on behalf of Ca|RT?

The key question is not about how many collapses had been predicted by users, but how manynoc the user predicted disasters actually happened.

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7 hours ago, mayalld said:

I suspect that the point he was making was that there was no question that a lack of funds had led to a failure to properly maintain the reservoir

well, he needs to learn how to communicate!

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