Middlewich Branch breach - Shropshire Union

[Captain Pegg]

40 minutes ago, Rob-M said:

If it is repaired by August then we will be ok as I think that is when we are most likely going to be looking at cruising the Middleweight branch.

Hopefully CRT will improve the design and when it's finished it will be the Heavyweight branch.

[Alway Swilby]

There's rumours doing the rounds on facebook that there can be a temporary repair up and running in 3 weeks. Then a stoppage from September to Christmas to fix it properly. But as I say this is only a facebook rumour.

[Rob-M]

27 minutes ago, Captain Pegg said:

Hopefully CRT will improve the design and when it's finished it will be the Heavyweight branch.

Bl@#y autocorrect.

[system 4-50]

2 hours ago, LadyG said:

There are too many badgers. Once they burrowed and lived in woodland, causing liltte harm, now they are widespread causing destruction and disease. There are a lot of fluffy bunnies out there who do not understand nature "tooth and claw". The kind of people who brought hedgehogs to the Western Isles, causing the decimation of ground nesting bird populations.

It took polititians about thirty years to effect any badger control, as the link between them and cattle disease could not be proved, that means that the disease which was eradicated in cattle circa 1960, took hold again, and is now endemic in badgers and other wild animals. I can't think that it could be eradicated without wholesale slaughter of badgers, and there is no political will for that.

It took many months to eradicate the fluffy bunnies from this website.

[ditchcrawler]

3 hours ago, canals are us? said:

It sounds expensive either way. I suppose that if you in-filled the breach in the bank you create pressure where the old and new joins.

Unless of course for a badger cull for TB. Have badgers or rabbits ever caused a breach? Surely if badgers had, they could be humanely rehomed by a licensed contractor rather than cause an expensive breach?

James

I think they got the blame on the Llangollen above Hampton Bank

edit to add link

https://www.dailypost.co.uk/news/north-wales-news/badgers-could-caused-llangollen-canal-2773979

Edited March 16, 2018 by ditchcrawler

[Tim Lewis]

Couple of good pictures:

 

Tim

[rgreg]

Just saw this on fb

https://video-lhr3-1.xx.fbcdn.net/v/t43.1792-2/28796451_233358333902284_1781281117001744384_n.mp4?_nc_cat=0&efg=eyJybHIiOjI5MTEsInJsYSI6MTAyNCwidmVuY29kZV90YWciOiJzdmVfaGQifQ%3D%3D&oh=8528faee93b2332d8ffeb60907af1130&oe=5AAC558C

[canals are us?]

13 minutes ago, rgreg said:

Just saw this on fb

https://video-lhr3-1.xx.fbcdn.net/v/t43.1792-2/28796451_233358333902284_1781281117001744384_n.mp4?_nc_cat=0&efg=eyJybHIiOjI5MTEsInJsYSI6MTAyNCwidmVuY29kZV90YWciOiJzdmVfaGQifQ%3D%3D&oh=8528faee93b2332d8ffeb60907af1130&oe=5AAC558C

Certainly looks bad. Hope the canal bridge is ok as the breach right beside. I have lived in Georgian and Edwardian houses and the foundations were virtually non existent, so hope the water hasn't undermined the bridge/ aqueducts foundations. I certainly wouldn't of stood where the person took the video! All looks really unstable and very steeply banked when built.

James 

Edited March 16, 2018 by canals are us?

[nicknorman]

1 hour ago, Captain Pegg said:

Earthworks constructed in the Georgian and Victorian periods pre-date the establishment of the discipline of geotechnical engineering and are effectively non-engineered structures. They were built with non-homogenous materials with little understanding of the properties of the material or the mechanisms by which they could fail.

Standard practice was to construct slopes with sides battered at 1:1.5; an engineered solution would have given something in the order of 1:3 for the materials concerned. This can be seen in the difference in angle of modern motorway earthwork slopes compared to older canals and railways. In theory these assets have a negative safety factor; in practice you know they don't because they remain standing.

The reality is that you are intrinsically operating around the limits of capability and to make matters worse the properties of soils change over time and not just seasonal either, it can be over decades or centuries. As a result they are flexible assets and they all exhibit some form of movement over a greater or lesser timespan. Inspection isn't easy and a general visual inspection may identify immediate exceptional issues but it isn't sufficient for overall management. That requires a qualified inspector.

It is certainly possible to calculate the risk associated with individual assets and prioritise work accordingly. In my job a few years ago I was accountable for 14,000 earthwork assets and conducted an exercise to risk rank them, a process which identified 72 highest risk assets. Programmes of work were put in place for those assets and mitigation measures imposed for periods of extreme wet weather (with a budget the folks at CRT could probably only dream about). However the collective risk associated with the 13,928 assets that weren't highest risk by far outweighed the collective risk of the 72 highest risk assets. That meant I could in no way guarantee that if there was a failure it would be of a highest risk asset. The nature of these events is that they are highly subjective to localised conditions.

CRT have the problem that their threshold for catastrophic failure is pretty low. Initial failure is likely to be a rotational slip where a segment of soil rotates and causes a shearing effect at the slope surface at the top of the rotation. If that causes a loss in the integrity of the puddled lining of the canal the leakage of water will liquefy the soil and cause it to flow, in turn this will make a bigger breach and then washout will follow. It looks a lot more spectacular than I suspect it is in reality.

i am sure they could do more and will seek to do so as that's pretty much the life of an asset manager who has to work within resource and funding constraints to minimise risk.

JP

I know you and I have had “history” and thus you will think I am just getting at you / point scoring etc. BUT I think that this post represents all that is wrong with modern civil engineering. In other words, all about the numbers, the “management speak” and the pseudo-science. The reality is that in ~1830 they had none of that. They did however have the experience to look at a situation with an open mind and make qualitative assessments and consequentially built stuff that lasted getting on for 200 years, instead of the typical design lives of 25 years these days. Quantitive assessments such as you are describing, don’t work in a real world which is chaotic, not idealistically homogeneous.

[RLWP]

1 minute ago, nicknorman said:

I know you and I have had “history” and thus you will think I am just getting at you / point scoring etc. BUT I think that this post represents all that is wrong with modern civil engineering. In other words, all about the numbers, the “management speak” and the pseudo-science. The reality is that in ~1830 they had none of that. They did however have the experience to look at a situation with an open mind and make qualitative assessments and consequentially built stuff that lasted getting on for 200 years, instead of the typical design lives of 25 years these days. Quantitive assessments such as you are describing, don’t work in a real world which is chaotic, not idealistically homogeneous.

That would be about the time they built the Aston embankment of the Grand Junction railway, that kept slipping for years

Only the stuff capable of lasting 200 years is still here, some stuff failed quickly and is - of course - not here

Richard

[nicknorman]

8 minutes ago, RLWP said:

That would be about the time they built the Aston embankment of the Grand Junction railway, that kept slipping for years

Only the stuff capable of lasting 200 years is still here, some stuff failed quickly and is - of course - not here

Richard

Maybe. But set against that, how much of the stuff we build now will still be around in 200 years? Not a lot, I would say! I have a thing about qualitative vs quantitative, probably stemming from when I read ZATAOMM as a yoof.

[David Mack]

5 minutes ago, nicknorman said:

Maybe. But set against that, how much of the stuff we build now will still be around in 200 years? Not a lot, I would say! I have a thing about qualitative vs quantitative, probably stemming from when I read ZATAOMM as a yoof.

There's a bridge in Florida which lasted for 5 days.

[RLWP]

8 minutes ago, nicknorman said:

Maybe. But set against that, how much of the stuff we build now will still be around in 200 years? Not a lot, I would say! I have a thing about qualitative vs quantitative, probably stemming from when I read ZATAOMM as a yoof.

You mean a road trip book?

Can I suggest you read some engineering history

[roland elsdon]

So to summarise

the canal breached for some reason ( wet winter)

the waters gone

a few boats are stranded

there are many bridges presuambly because of the embankment there will be stop plank grooves allowing a temporary  refill to move the boats

then structural engineers will carefuly assess.

residential boats may be involved there is no special responsibilty to them crt, council will not be involved you are visitors not paying extra charges for being residential , nor local taxes. (I was once described as a vagrant living in a chattel in a law court...for living on my boat by a barrister attempting to discredit a professional witness statement i made as part of my work.) . However most insurance assists in stranding.

its nothing new but a pain, fortunately a link canal not trunk.

[nicknorman]

Just now, RLWP said:

You mean a road trip book?

Can I suggest you read some engineering history

If you have never read it, I can heartily recommend it. If you have read it and really think it is a road trip book, sorry but you have just gone down in my estimation!

[canals are us?]

I really like old buildings, and if I ever won the lottery I'd buy a small manor house with gate lodge so my grandparents can live in it. It always annoys me when they say some owner built it rather than "had it built" as if the owner actually built it.

James

[Captain Pegg]

27 minutes ago, RLWP said:

That would be about the time they built the Aston embankment of the Grand Junction railway, that kept slipping for years

Only the stuff capable of lasting 200 years is still here, some stuff failed quickly and is - of course - not here

Richard

Brunel built many timber viaducts that were replaced over a century ago. He did it for much the same reason that things are sometimes today specified for short service lives; his client wasn't willing to pay for a higher specification.

Linking all the marvellous feats of civil engineering on the Great Western Railway he built all the embankments in over-consolidated clays that have spent the 180 years since trying to recover their shape necessitating many many millions of pounds of corrective work along the route. He did that because he didn't understand the material. For the opposite reason he was able to design the Clifton suspension bridge and build the Royal Albert bridge.

JP

Edited March 16, 2018 by Captain Pegg

[RLWP]

Just now, Captain Pegg said:

Brunel built ....

JP

Another person who is idealised in modern times. If you look at all he did was one of many doing much the same.

Brunel's significant genius was probably in self promotion, he was an awful mechanical engineer, had serial failures yet was a very good civil engineer. Nowadays he's almost the face of Victorian engineering

 

[rusty69]

10 minutes ago, nicknorman said:

If you have never read it, I can heartily recommend it. If you have read it and really think it is a road trip book, sorry but you have just gone down in my estimation!

Its a great book. I tried reading Lila recently after mr Pirsigs death but had trouble getting into it. 

Will try again, cos its got boats in it. 

Edited March 16, 2018 by rusty69

[Captain Pegg]

44 minutes ago, nicknorman said:

I know you and I have had “history” and thus you will think I am just getting at you / point scoring etc. BUT I think that this post represents all that is wrong with modern civil engineering. In other words, all about the numbers, the “management speak” and the pseudo-science. The reality is that in ~1830 they had none of that. They did however have the experience to look at a situation with an open mind and make qualitative assessments and consequentially built stuff that lasted getting on for 200 years, instead of the typical design lives of 25 years these days. Quantitive assessments such as you are describing, don’t work in a real world which is chaotic, not idealistically homogeneous.

The Victorians did some good things with bricks. A material notable for its ability to be patch repaired. 200 year old Trigger's brooms.

Do you genuinely believe the engineering that put man on the moon, achieved supersonic flight, tunnelled under the Channel and bridged between Denmark and Sweden couldn't do what the Victorians did?

JP

[Captain Pegg]

16 minutes ago, RLWP said:

Another person who is idealised in modern times. If you look at all he did was one of many doing much the same.

Brunel's significant genius was probably in self promotion, he was an awful mechanical engineer, had serial failures yet was a very good civil engineer. Nowadays he's almost the face of Victorian engineering

 

He was probably the most educated, numerate and socially mobile of his generation.

Sounds like the things that Nick suggests are wrong with today's engineers.

JP

[RLWP]

Just now, Captain Pegg said:

He was probably the most educated, numerate and socially mobile of his generation.

Sounds like the things that Nick suggests are wrong with today's engineers.

JP

I offer George Stephenson

[RLWP]

37 minutes ago, nicknorman said:

If you have never read it, I can heartily recommend it. If you have read it and really think it is a road trip book, sorry but you have just gone down in my estimation!

You seem to think that might matter

[Captain Pegg]

23 minutes ago, RLWP said:

I offer George Stephenson

Was certainly better with cucumbers than Brunel.

[Peter Thornton]

5 hours ago, Marshian said:

If the LA could discharge its statutory homelessness duty with a cardboard box, I'm sure they would. But they can't.  They can, however, argue that the root cause of the liveaboards' homelessness is a CaRT maintenance issue.  That's not turning CaRT into a housing authority; it's a housing authority holding CaRT responsible for homelessness due to canal disrepair

As someone who has worked in this field, the LA will have a duty to respond, and will do so. But it doesn't have the responsibility to provide free accommodation and most people will find relatives and friends to help out.