Tring Summit closure

[debbifiggy]

Are there any coal boats operating in this area that might not be aware of this news - would be good to let them know if so!

 

Phil on Hyperion and Jules on Towcester/Bideford etc already know. Don't think there are any other regular coal boats still operating in the area but I do still have Peter Hawker's telephone number if necessary.

 

D

[AJLintern]

So presumably if they stopped topping up the levels and allowed it to stabilise it would reveal the current height of the natural water table. Of course that might be below the bottom of the canal...! One assumes that the water table normally would either be at around the normal level of the canal, otherwise additional water pumped in would just spread out into the groundwater and the level drop back down to the water table level.

[Speedwheel]

local BW operational staff with a near lifetime's experience of maintenance in the area,

 

One is particularly upset as he was told that he will have to move his boat (which he lives) on down to Marsworth. If he is allowed I think he now plans to just push the boat out a bit and let it sit on the bottom. He has also just bough another boat which will remain stuck to the south of the stoppage.

 

I wonder haw many BW workers there are left who have a genuine passion and love for, and knowledge of, the waterways?

Edited January 10, 2012 by Speedwheel

[magnetman]

Will they try shutting the Wendover arm off and see if that makes any difference?

 

Apparently it has a history of severe water loss through its banks.

 

http://wendoverarmtrust.co.uk/about-the-canal/

[alan_fincher]

Will they try shutting the Wendover arm off and see if that makes any difference?

 

Apparently it has a history of severe water loss through its banks.

 

http://wendoverarmtrust.co.uk/about-the-canal/

That is beyond the bit that remains open!

 

The short stretch that has so far reopened, and beyond the stop lock, and later bund put in to protect from water loss, has so far as I know been completely relined. The same will apply to the known leaky bits in the yet to be reopened part.

 

The "currently open bit" not only acts as feeder to the GU summit, both for water pumped in at Tringford, but also that that comes from the culvert that still carries important supplies through the bit that is currently dry.

 

Unless planks go in anywhere else, if they drop the summit a foot, they will also be dropping the "open" bit of the wendover a foot, as it is all the same pound.

[jenlyn]

I do hope BW use the opportunity to clear some of the crap in the pound from tring to bulbourne

[alan_fincher]

So presumably if they stopped topping up the levels and allowed it to stabilise it would reveal the current height of the natural water table. Of course that might be below the bottom of the canal...! One assumes that the water table normally would either be at around the normal level of the canal, otherwise additional water pumped in would just spread out into the groundwater and the level drop back down to the water table level.

 

I'm no geologist or hydrologist, but much of the affected length is in the very deep Tring cutting, whereas other parts, (like the Wendover Arm stretch just mentioned), is broadly at the level of the surrounding fields.

 

I'm purely guessing, but wouldn't you expect the water table to be much higher (relative to the cut), in the cutting, because the cut there is many metres below ground level ?

 

But we also learn some (possibly all) of the cutting is unpuddled ? Presumably because with water table at "normal" levels, the net effect is water gained into the canal, not lost out of it?

 

I would expect, (but don't know for certain), that on stretches where the canal is not in a cutting, then puddling would be present to prevent losses, as the water table will generally be lower, (again relative to the canal), and water draining out, rather than in might be expected, even in 2normal" conditions.

 

As I say, no expert, but tend to share Allan Jones' concern that when you leave a level dropped for long periods things can dry out, (even puddle clay, if allowed to), and it may leak far worse if and when it is refilled. Hopefully us non geologists are guessing wrong, or big trouble ahead!

 

I do hope BW use the opportunity to clear some of the crap in the pound from tring to bulbourne

Will this be being put there by anybody left trapped in, who can't then access the sanitary station ?

[BEngo]

That is beyond the bit that remains open!

 

The short stretch that has so far reopened, and beyond the stop lock, and later bund put in to protect from water loss, has so far as I know been completely relined. The same will apply to the known leaky bits in the yet to be reopened part.

 

The "currently open bit" not only acts as feeder to the GU summit, both for water pumped in at Tringford, but also that that comes from the culvert that still carries important supplies through the bit that is currently dry.

 

 

 

The water from the Wendover pipeline does not directly enter the summit, but runs into the Tring reservoirs (Alan Faulkners book on the Grand Junction Canal has the details) and then has to be pumped back into the open bit of the Wendover at Tringford. When BW stop feeding the summit this water will stay in the reservoirs. The feeder at New Mills will still go directly into the summit, and together with Tring Sewage works and the Southern Railway Feeder outflows will be the main feeds to the closed summit. ISTR we are not talking lots of locksfull per day from these, even in wet weather. Of course if the cut really is above the current water table it will all run out again anyway.

 

Gavin is (was) the wizard on where the Tring summit water comes from and where it can be moved to or from.

 

If I were stupid enough to be heading for the public money waste fest in the East End this year I would be betting on going via Oxford. What prospect that BW don't have enough water to collect on all those Temporary mooring fees north of Uxbridge?

 

I see the Northern Engines are going to be automated, (which won't increase the water supply at all, but may recycle a little of it) but does anyone know how this water either gets up Maffers or is run into the Tring reservoirs so it can be pumped by the Trinford pumps? I don't recall a pump at Marsworth at all.

 

N

[GUMPY]

This means that the line 300mm down becomes the new "top part" and therefore becomes the most leaky. When (if?) the level is restored to normal, that part is now 300mm below the water level so presumably becomes far more leaky than ever before.

Which is exactly what happened on the K&A so they reverted to the lower level............and people now wonder why its shallow

[beardshave]

I'm waiting for the influx of boats tomorrow all trying to squeeze in to the short stretch between Cow Roast lock and New Ground Road bridge. There ain't enough room. With the Bulbourne end of the pound closed off the area will be down a water point and a winding hole. Cow Roast is gonna get hideous for the next two months.

 

I thought you would like to see the following extract from BW's Press Release

 

"The Cowroast location is only sufficient for existing long term Cowroast moorers, existing Cowroast and Dudswell winter moorers. Other boats will be asked to vacate this area."

So no problem.

[LEO]

I'm no geologist or hydrologist, but much of the affected length is in the very deep Tring cutting, whereas other parts, (like the Wendover Arm stretch just mentioned), is broadly at the level of the surrounding fields.

 

I'm purely guessing, but wouldn't you expect the water table to be much higher (relative to the cut), in the cutting, because the cut there is many metres below ground level ?

 

 

The level of water table can be judged by checking the open drain/culvert which flows down the cutting side on the towpath side just north of Marshcroft bridge. It rarely flows and then only after a period of heavy rain.

 

The cutting side are now heavily wooded and trees take a lot of moisture from the soil.

 

Bearing in mind stored water available to canals throught the Southern Region, stoppages such as this be be commonplace, I suspect access by water to shows such as Crick and Braunston will be very difficult for large numbers of boats.

 

Leo.

[sheriff]

Would it better in the long term if BW/C & R kept Tring summit closed in order to line the canal at the summit and take this oppurtunity to find all the problems....which contribute to water loss..

 

and perhaps maybe when it does open,have limited use of the locks to ensure less water loss,when the weather is very dry... the canal is an old system.needs serious money and time to repair.

 

maybe shut the system down completely in winter to really give the water tables time to recover.....

[GUMPY]

The cutting side are now heavily wooded and trees take a lot of moisture from the soil.

 

 

Lets get it put back to how it used to be

Cut the sodding trees down not just at Tring but all over the system

Return it to grass banks as it used to be when it was built.

Will solve the water extraction from the canals by the trees and provide a decent fuel source for boaters in the winter of 2014

[LEO]

Would it better in the long term if BW/C & R kept Tring summit closed in order to line the canal at the summit and take this oppurtunity to find all the problems....which contribute to water loss..

 

and perhaps maybe when it does open,have limited use of the locks to ensure less water loss,when the weather is very dry... the canal is an old system.needs serious money and time to repair.

 

maybe shut the system down completely in winter to really give the water tables time to recover.....

 

But where does the money come from? - boaters are the ony users who need canals for through navigation everybody else can make do with a series of disconnected ponds.

 

The summit is about 3 miles long, plus the lenght of the Wendover Arm - a lot to re-line.

 

It's an old chestnut.

 

Leo.

[alan_fincher]

Would it better in the long term if BW/C & R kept Tring summit closed in order to line the canal at the summit and take this oppurtunity to find all the problems....which contribute to water loss..

 

and perhaps maybe when it does open,have limited use of the locks to ensure less water loss,when the weather is very dry... the canal is an old system.needs serious money and time to repair.

 

maybe shut the system down completely in winter to really give the water tables time to recover.....

The issue, as I understand it, if you believe BWs numbers, (and I'm not sure there is any reason not to, in this case), that neither actual lock usage, or lock leakage are very significant numbers compared to those vast volumes just said to be draining out of the canal.

 

So shutting it down, (only), would achieve close to nothing, which is why they have gone for more draconian measures, (even if only lowering it a foot might sound to the uninitiated as maybe not going to stop the leakage, or as possibly causing more leakage if and when they refill).

 

Apart from cost, I'm guessing, (but again don't know for certain), that relining might be a "bad thing" at times when water tables are higher. If the result of "no lining" allows more excess water to flow in than out then that is actually "a good thing". Apparently the fact that the reverse is happening on a grand scale is because the water table has remained abnormally low ?

[bizzard]

But where does the money come from? - boaters are the ony users who need canals for through navigation everybody else can make do with a series of disconnected ponds.

 

The summit is about 3 miles long, plus the lenght of the Wendover Arm - a lot to re-line.

 

It's an old chestnut.

 

Leo.

If everyone had tipped their stoves ash out into the water of the Tring cutting over the years it would probably have sealed it and this trouble wouldn't be happening.-------I suspect they did though.

[BEngo]

But where does the money come from? - boaters are the ony users who need canals for through navigation everybody else can make do with a series of disconnected ponds.

 

The summit is about 3 miles long, plus the lenght of the Wendover Arm - a lot to re-line.

 

It's an old chestnut.

 

Leo.

 

 

You don't want to re-line anyway. First, the cutting was never lined so that the groundwater could percolate INTO the canal and second if you do line it, in a wet spell groundwater pressure will build up under the lining until it ruptures.

 

Cutting the trees down is OK in the short term, but will not help as the roots rot and the cuttings become destabilised. Nor will CART want the additional continuing expense of maintaining the grass banks so that the trees don't come back.

 

What we need are some competent waterways managers who do not need 3 months to notice that about 20 boat movements a week is using 220 lockfuls of water and that the pump at Cowroast is flat out all day every day; managers who do control their water resources and maintenance so that water is not deliberately wasted and managers who do get out of their office occasionally. There are, and have been for years, I think 7 locks on the Aylesbury arm alone that are supposed to be left empty because they leak so badly from the structure and another 3 or 4 between Cowroast and Berko. Despite record low levels in the Tring reservoir group there were no restrictions on the use of Marsworth until very recently. The Aylesbury Arm was only closed when the dredging programme was killing the fish and there was not enough water to move the dredger. What has Mr. Whyatt been doing? Certainly not what I think a Waterway Manager is for.

N

Edited January 10, 2012 by BEngo

[jenlyn]

You don't want to re-line anyway. First, the cutting was never lined so that the groundwater could percolate INTO the canal and second if you do line it, in a wet spell groundwater pressure will build up under the lining until it ruptures.

 

Cutting the trees down is OK in the short term, but will not help as the roots rot and the cuttings become destabilised. Nor will CART want the additional continuing expense of maintaining the grass banks so that the trees don't come back.

 

What we need are some competent waterways managers who do not need 3 months to notice that about 20 boat movements a week is using 220 lockfuls of water and that the pump at Cowroast is flat out all day every day; managers who do control their water resources and maintenance so that water is not deliberately wasted and managers who do get out of their office occasionally. There are, and have been for years, I think 7 locks on the Aylesbury arm alone that are supposed to be left empty because they leak so badly from the structure and another 3 or 4 between Cowroast and Berko. Despite record low levels in the Tring reservoir group there were no restrictions on the use of Marsworth until very recently. The Aylesbury Arm was only closed when the dredging programme was killing the fish and there was not enough water to move the dredger. What has Mr. Whyatt been doing? Certainly not what I think a Waterway Manager is for.

N

well said!

[Davidss]

...

Apart from cost, I'm guessing, (but again don't know for certain), that relining might be a "bad thing" at times when water tables are higher. If the result of "no lining" allows more excess water to flow in than out then that is actually "a good thing". Apparently the fact that the reverse is happening on a grand scale is because the water table has remained abnormally low ?

The thought occurs to me that, when that section of the canal system was built, they made use of the high water table to fill the summit pound. This wasn't special, just an alternative use of the normal natural flow from springs, streams, rivers, etc, that was normally used to fill the summit of all canals.

 

Nowadays it seems a lot of the system is run on pumped water, this wasn't generally viable when the canals were being built, but is obviously felt to be a viable solution now. Wherever a pumped (back pumped) supply system has been installed, there must have been a day, week, or month, when whoever was in charge said "we have to do something, and pumping plus pipes is that something". At the time of this realisation the proposed solution will have been a surprise to some onlookers.

PERHAPS we are at that stage now. The situation is different to when the summit was built, and the economic decision now is to line the canal and pump water into it. Sure, it seems radical and expensive to some onloookers, but 'twas ever thus'.

For now, people struggle. It may take a few years to get the finance put together, but eventually it will be done, the work completed, and it will be just another piece of hidden infrastructure, just like all the pumps that work now.

 

I am reminded of the Leawood Pump on the Cromford canal.

Initially it wasn't required. Ground water flow changed, canal water ran short, and after several years the pumping station was built, solving the water shortage problem.

Then, the driver was business economics of a transport system, now it's leisure economics of a (mainly) leisure system. That doesn't make spending money less viable.

 

Just an aside in this thread, as most people will be worrying about the 'now', but a few will have to think of the future.

 

Good Luck Alan, I think you are being very brave (possibly in 'Yes Minister' terms!) but I'm glad someone has the energy and interest.

 

Regards.

 

You don't want to re-line anyway. First, the cutting was never lined so that the groundwater could percolate INTO the canal and second if you do line it, in a wet spell groundwater pressure will build up under the lining until it ruptures.

...

It would appear the groundwater conditions have changed, so different actions are needed to meet those changed conditions.

 

I understand ground water pressure was responsible for damaging the 'natural' bed of the route to Buxworth basin. Once the problem was identified the offending section was lined. I understand that problem has been solved - although there might be other problems, I don't think the route has been closed.

 

Regards.

Edited January 10, 2012 by Davidss

[BlueStringPudding]

I thought you would like to see the following extract from BW's Press Release

 

"The Cowroast location is only sufficient for existing long term Cowroast moorers, existing Cowroast and Dudswell winter moorers. Other boats will be asked to vacate this area."

So no problem.

Grr. Maybe it's a scam to winkle more winter mooring fees out of people

 

I do hope BW use the opportunity to clear some of the crap in the pound from tring to bulbourne

That's what I said when I heard about the stoppage. I'm sure if BW go about it the right way, they could ask local boaters to pull together as a volunteer party to help. We'd all like to see the visitor moorings moorable and visitable and not full of rocks and kack

Edited January 10, 2012 by BlueStringPudding

[Chalky]

 

If I were stupid enough to be heading for the public money waste fest in the East End this year I would be betting on going via Oxford.

 

 

And the reservoirs on the South Oxford are already at an historic low for December according to the BW hydrology pages.

 

http://www.waterscape.com/features-and-articles/features/british-waterways-reservoir-watch

 

I suspect that the South Oxford will soon go the same way as the GU.

[Hairy-Neil]

 

maybe shut the system down completely in winter to really give the water tables time to recover.....

 

Don't be rediculous. That's the best time of year to be boating....

[matty40s]

Don't be rediculous. That's the best time of year to be boating....

absolutely, greenie, maybe even a bluie!!!

[Hairy-Neil]

Lets get it put back to how it used to be

Cut the sodding trees down not just at Tring but all over the system

Return it to grass banks as it used to be when it was built.

Will solve the water extraction from the canals by the trees and provide a decent fuel source for boaters in the winter of 2014

 

That's like a fishermans rant, kill the seals, they're eating our fish....

 

Some would say the trees shade the canal from direct sunlight, thus reducing evaporation....

[jenlyn]

Grr. Maybe it's a scam to winkle more winter mooring fees out of people

 

 

That's what I said when I heard about the stoppage. I'm sure if BW go about it the right way, they could ask local boaters to pull together as a volunteer party to help. We'd all like to see the visitor moorings moorable and visitable and not full of rocks and kack

Actually, I would put my hands up for that if I could get me boat close ish