Grand Union Canal water transfer scheme latest

[IanD]

4 minutes ago, PeterF said:

I did a calc and agree with the 0.5mph. However, put put a full sized wide beam in the tunnel taking up lets say 75% of the available flow area and if the widebeam is stationary the current will be 2mph to get around the boat let alone make any headway. Therefore, the boat will not make any progress at low cruising revs. Has CRT thought about this yet or have I got something wrong.

Surely the tunnel is deep enough (4 feet?) that the widebeam (2' draft?) will take a much smaller fraction of are than this? 75% of width and 50% of depth leaves 62.5% free, so 0.5mph will go up to 0.8mph, should be no problem...

[PeterF]

Devils advocate, taking full width and deep widebeam as a worst case. Have to consider the worst case not the average modern shallow 12'6" eurocruiser

[IanD]

1 minute ago, PeterF said:

Devils advocate, taking full width and deep widebeam as a worst case. Have to consider the worst case not the average modern shallow 12'6" eurocruiser

Even though it's unlikely, a widebeam that size which can't make headway against a 2mph current probably shouldn't be on the canals... 😉

 

(and I'd like to see anyone get a widebeam that big anywhere on the GU...)

[David Mack]

5 hours ago, BEngo said:

 

I am sure that the cost of pumping it all up Hillmorton, Braunston and from Fenny to Leighton will not be cheap.

But it will be less than the cost of pumping it through a pipeline all the way.

5 hours ago, BEngo said:

If my fag packet is accurate,  115 million litres a day from the Coventry to Lygetune Beaudesert  will need  about a 1/2  a mile per hour southbound  current in Blisworth tunnel.

Where's that information from?

 

If the water speed is 0.5mph in a channel 14 feet wide by 4 feet deep, then what speed will it be going through the bywashes?  I imagine they are going to need substantial enlargement (on the downhill to London locks). And very long weir crests to limit the rise in water level between no flow and full flow - either that or some automatically regulated sluices.

[ditchcrawler]

53 minutes ago, PeterF said:

I did a calc and agree with the 0.5mph. However, put put a full sized wide beam in the tunnel taking up lets say 75% of the available flow area and if the widebeam is stationary the current will be 2mph to get around the boat let alone make any headway. Therefore, the boat will not make any progress at low cruising revs. Has CRT thought about this yet or have I got something wrong.

That sounds good, I think we should fully support it 😁

15 minutes ago, IanD said:

Even though it's unlikely, a widebeam that size which can't make headway against a 2mph current probably shouldn't be on the canals... 😉

 

Unless it was electrically powered 🤑

 

[BEngo]

11 hours ago, David Mack said:

16 hours ago, BEngo said:

 

Where's that information from?

The  115 million litres  a day was in the NCE  article linked.  I produced an engineering estimate  ( aka guess) for the cross section of Blisworth,  of 5 square metres, based on the concrete section and because I have no feel for the depth of water in Braunston.   After that it was arithmetic.

 

 

N

[Tonka]

A Vlockie at Atherstone was telling me only this week all about it. 

Apparently they are going to build pipeline from Minworth to the top of Atherstone and then the water goes into the Coventry Canal and then goes by canal down to a new plant being built at Leighton Buzzard. A bonus is that the water level will improve on the Coventry canal

[ditchcrawler]

4 hours ago, Tonka said:

A Vlockie at Atherstone was telling me only this week all about it. 

Apparently they are going to build pipeline from Minworth to the top of Atherstone and then the water goes into the Coventry Canal and then goes by canal down to a new plant being built at Leighton Buzzard. A bonus is that the water level will improve on the Coventry canal

I will just have to make sure I do rings then and not just out and back, that way it will always be down stream with the flow

[Ewan123]

I wonder whether this proposal would have any effect on sediment build-up and water quality/appearance on the canals concerned. I would expect the treated wastewater to at least appear clear, it might even be better quality than the stuff in the canal already (being full of agricultural runoff etc.) without a sediment load, so perhaps it might lead to a slight reduction in that at least. Or maybe it would just move sediment downstream with pounds acting as settling tanks. 🤔

[cuthound]

5 hours ago, Tonka said:

A Vlockie at Atherstone was telling me only this week all about it. 

Apparently they are going to build pipeline from Minworth to the top of Atherstone and then the water goes into the Coventry Canal and then goes by canal down to a new plant being built at Leighton Buzzard. A bonus is that the water level will improve on the Coventry canal

 

If it improves the level by much some of the bridges and associated towpaths will need raising...

[David Mack]

46 minutes ago, Ewan123 said:

I would expect the treated wastewater to at least appear clear, it might even be better quality than the stuff in the canal already (being full of agricultural runoff etc.)

Since, in the absence of a transfer scheme, this effluent will be discharged to watercourses anyway, it should already be treated to the appropriate standard. Which isn't to say that there aren't problems with existing practice.

[Ewan123]

1 hour ago, David Mack said:

Since, in the absence of a transfer scheme, this effluent will be discharged to watercourses anyway, it should already be treated to the appropriate standard. Which isn't to say that there aren't problems with existing practice.

Well yes, quite.

[Pluto]

2 hours ago, Ewan123 said:

I wonder whether this proposal would have any effect on sediment build-up and water quality/appearance on the canals concerned. I would expect the treated wastewater to at least appear clear, it might even be better quality than the stuff in the canal already (being full of agricultural runoff etc.) without a sediment load, so perhaps it might lead to a slight reduction in that at least. Or maybe it would just move sediment downstream with pounds acting as settling tanks. 🤔

As now, any water movement will tend to allow rubbish to move along the bed of the canal to be dumped beyond bridgeholes as the water flow slows after passing the narrows. Anyone with a reasonable understanding would require extensive dredging to keep navigation relatively easy, though I can't see that happening given the cost. Historically, dredging was often done either side of bridgeholes as that was where rubbish collected.

[ditchcrawler]

On country file now on BBC1, Minworth Sewage to the GU

[Chris Lowe]

Didn't go into any detail of how they would do it though.

[Tonka]

1 minute ago, buccaneer66 said:

Didn't go into any detail of how they would do it though.

probably because they do not know. I was told that the water would go by natural means from Atherstone to Leighton Buzzard. 

Not sure how it will go up Hawksbury Stop Lock, Hillmorton 3 Locks & Braunston Locks

[magnetman]

I suppose there arrr probably people about who think going  by canal from London to Birmingham involves locks always going either up or down.

 

Easy assumption to make given the term "I'm going up to London". Trains use the up and down terminology as well.

 

 

[Machpoint005]

On 15/06/2023 at 16:07, PNB116 said:

Given the water companies inability or reluctance to treat sewage waste, one worries that they might try to save some more money and just pump the water as sewage into London?

 

How will them Londoners be able to tell? Their tap water is disgusting at the best of times.

 

 

[Chris Lowe]

23 minutes ago, Machpoint005 said:

How will them Londoners be able to tell? Their tap water is disgusting at the best of times.

 

Tell me about it, I'm originally from Windsor and the water came out brown more than once.

[MtB]

2 hours ago, magnetman said:

I suppose there arrr probably people about who think going  by canal from London to Birmingham involves locks always going either up or down.

 

Easy assumption to make given the term "I'm going up to London". Trains use the up and down terminology as well.

 

 

 

Well it looks downhill all the way when I look at the route on my globe. 

 

 

[Chris Lowe]

2 minutes ago, MtB said:

Well it looks downhill all the way when I look at the route on my globe. 

Have you got your globe the right way up?

[MtB]

3 minutes ago, buccaneer66 said:

Have you got your globe the right way up?

 

 

Oh, good point. London goes at the top, dunnit! 

 

 

[BEngo]

13 hours ago, Tonka said:

probably because they do not know. I was told that the water would go by natural means from Atherstone to Leighton Buzzard. 

Not sure how it will go up Hawksbury Stop Lock, Hillmorton 3 Locks & Braunston Locks

Depends on the relative levels of Minworth sewage and Braunston summit.  Minworth is about 13 locks up from Fazeley so probably higher than the top of Atherstone.   If so a pipeline might not need pumping from Minworth  to Hawkesbury, depending on size,  desired flow rates and head losses etc.

N

 

[Alan de Enfield]

16 hours ago, magnetman said:

I suppose there arrr probably people about who think going  by canal from London to Birmingham involves locks always going either up or down.

 

I have always found that assumption to be true - very few locks don't actually allow the boat to ascend (go up) or descend (go down)

[magnetman]

I'm sure it won't be long before the CRT achieve locks which do neither.