River Nene locks

[blackrose]

This is probably somewhere else on the forum. I can't see it but my apologies if it's been posted elsewhere.

 

Travelling up the Nene I came to Titchmarsh lock last night and the guillotine gate had been left closed. I thought it was just some lazy idiot who hadn't emptied the lock but someone at the MNCC told me that the EA had instructed that the lock be left full with the guillotine gate closed to reduce water losses. She told me when I leave the lock to leave it full with the top gates open. 

 

Then early this morning I met a couple on a boat coming the other way who had spoken to the EA yesterday and been told to leave the locks however they wanted!

 

Today I met a couple who thought they should be leaving the lock full with all gates closed. Apparently an email went around but I didn't receive it and they didn't get it either.

 

There are no notices at the locks and I've searched the EA website for notices to mariners but perhaps I've missed it? 

 

It's a bit confusing and unless everyone's doing the same thing then it's pretty chaotic. 

 

 

[rusty69]

It does get a mention on the  EA facebook page

 

https://www.facebook.com/AnglianWaterwaysEA

 

And on the website

 

https://www.visitanglianwaterways.org/navigation-notices-river-nene

 

Edited July 28, 2022 by rusty69

[blackrose]

Ok thanks. I'm not a facebooker and missed it on the website. 

[Scholar Gypsy]

You can subscribe to alerts here,  https://teamup.com/ks42748cc81f4df974

Click on the "person" icon top right, create an account, and then set up alerts for this calendar.  You will then get an email when anything changes.  The same facility is available on the Ely Ouse Calendar

https://teamup.com/ks7f3fcbc3e94ed8f0

The notice is not hugely clear. Basically when leaving the lock (in either direction) just make sure all the slackers are down and leave the gates you have just used open.  That's the same as for the locks with V doors at both ends,

Edited July 28, 2022 by Scholar Gypsy

[blackrose]

Thanks, I did sign up for alerts a couple of years ago but don't seem to be getting them.

 

2 hours ago, Scholar Gypsy said:

You can subscribe to alerts here,  https://teamup.com/ks42748cc81f4df974

Click on the "person" icon top right, create an account, and then set up alerts for this calendar.  You will then get an email when anything changes.  The same facility is available on the Ely Ouse Calendar

https://teamup.com/ks7f3fcbc3e94ed8f0

The notice is not hugely clear. Basically when leaving the lock (in either direction) just make sure all the slackers are down and leave the gates you have just used open.  That's the same as for the locks with V doors at both ends,

 

What you're saying here about leaving gates open in whichever direction you leave the lock isn't actually what people are doing. As I said earlier, there seems to be a bit of confusion and different advice. 

[Scholar Gypsy]

6 hours ago, blackrose said:

Thanks, I did sign up for alerts a couple of years ago but don't seem to be getting them.

 

 

What you're saying here about leaving gates open in whichever direction you leave the lock isn't actually what people are doing. As I said earlier, there seems to be a bit of confusion and different advice. 

I agree the notice is rather unclear. There is an argument for boats going upstream shutting the V doors but leaving the lock full, as I would suspect the V doors leak less than the guillotine.

 

(That is certainly the case on those narrow canals with single top gates and twin bottom gates: the latter rarely seal well, which is why the guidance on most canals is to leave all gates and paddles shut).

[blackrose]

I thought the idea of leaving the guillotine gate down was that it leaked less than the V gates? Thats why we're doing it now isn't it? 

Edited July 29, 2022 by blackrose

[GUMPY]

8 minutes ago, blackrose said:

I thought the idea of leaving the guillotine gate down was that it leaked less than the V gates? They're why we're doing it now isn't it? 

 The V doors were all just below Weir level before they were raised a few years ago they were the lowest point of the flow.

The guillotine is usually higher than the V doors so will hold the water at a higher level than would normally be the case if it was open. Thus keeping the level up.

Edited July 29, 2022 by Loddon

[Scholar Gypsy]

24 minutes ago, blackrose said:

I thought the idea of leaving the guillotine gate down was that it leaked less than the V gates? They're why we're doing it now isn't it? 

No, I don't think that is the reason. 

 

To see why, imagine a stream of boats all day, downstream boats arriving on the hour and boats heading upstream arriving at 30 mins past. Let's also assume the gates make a perfect seal - they are better than many on the canals. 

 

With the normal mode of operation, with the boat heading upstream leaving the lock empty and the guillotine up, two lockfuls of water will be moved each hour from the upper reach to below the lock. 

With the new mode of operation,  only one lockful will be used, halving consumption. 

 

In practice, of course, the saving will be less than 50%, but it should still be significant (and will more closely match the consumption of the locks with  V doors at both ends).

 

PS I don't think Loddon's point is relevant here  as flows are so low.

[blackrose]

29 minutes ago, Loddon said:

 The V doors were all just below Weir level before they were raised a few years ago they were the lowest point of the flow.

The guillotine is usually higher than the V doors so will hold the water at a higher level than would normally be the case if it was open. Thus keeping the level up.

 

That's certainly the case at some locks. Lower Rigstead was overflowing the V gates when I came though yesterday. 

6 minutes ago, Scholar Gypsy said:

No, I don't think that is the reason. 

 

To see why, imagine a stream of boats all day, downstream boats arriving on the hour and boats heading upstream arriving at 30 mins past. Let's also assume the gates make a perfect seal - they are better than many on the canals. 

 

With the normal mode of operation, with the boat heading upstream leaving the lock empty and the guillotine up, two lockfuls of water will be moved each hour from the upper reach to below the lock. 

With the new mode of operation,  only one lockful will be used, halving consumption. 

 

In practice, of course, the saving will be less than 50%, but it should still be significant (and will more closely match the consumption of the locks with  V doors at both ends).

 

Yes I get that too. It always seemed a bit wasteful emptying the lock after going up. I also think the guillotine gates do seal better so perhaps they're now being left down for both reasons.. 

Edited July 29, 2022 by blackrose

[Scholar Gypsy]

1 minute ago, blackrose said:

 

That's certainly the case at some locks. Lower Rigstead was overflowing the V gates when I came though yesterday. 

In which case there is no water shortage there.  The other issue is the wide variation in lock volumes,  in particular Irthlingborough must be 3x the volume of Upper Ringstead and 2x Lower Ringstead. EA will be trying to reduce the water used at Irthlingborough. 

[Alway Swilby]

Talking of lack of water on the Nene, does navigation ever get suspended due to lack of depth? We need to travel from Peterborough up to Gayton but won't be able to start from Peterborough until late August.

[OldGoat]

We haven't 'done' the Nene for years, but being a river it's probably less prone  to water shortages than a canal as its function is one of drainage and being broad as well has more depth of water.

 

[GUMPY]

I've not heard of it happening, it's often the opposite problem😱

We are off down the Nene on the 25th off to the Middle Level for our holiday 🤭

[Big Bob W]

[GUMPY]

Won't be passing that bit it's upstream from where we start.

More worried about the fact that the notice hasn't come through on my feed 🤔

[PaulJ]

Outside Brittania

[Big Bob W]

34 minutes ago, PaulJ said:

Outside Brittania

We were hoping on heading down there tomorrow! No chance I’m guessing!

[PaulJ]

18 minutes ago, Big Bob W said:

We were hoping on heading down there tomorrow! No chance I’m guessing!

EA werent exaggerating about it being extremely low-I wasnt expecting to see that.

[GUMPY]

1 hour ago, PaulJ said:

Outside Brittania

That's exceptionally low.

Wasn't expecting it to be that bad

I think it's not river fed at that point so they will have to run water down.

Edited July 31, 2022 by Loddon

[PaulJ]

1 hour ago, Loddon said:

That's exceptionally low.

Wasn't expecting it to be that bad

I think it's not river fed at that point so they will have to run water down.

Seems to be a bit of it going on at the mo-I had assumed youngsters mucking about.

Few weeks ago as I dropped down Higham lock I noticed the River was about a foot or so down. Got to Irthlingborough lock and one of the paddles was at least halfway up.

At least if the guillotines are left down it might help stop some of it.

[GUMPY]

1 hour ago, PaulJ said:

Seems to be a bit of it going on at the mo-I had assumed youngsters mucking about.

Few weeks ago as I dropped down Higham lock I noticed the River was about a foot or so down. Got to Irthlingborough lock and one of the paddles was at least halfway up.

At least if the guillotines are left down it might help stop some of it.

I was going to say maybe its boaters that don't understand how  guillotine gates work.

After all it is possible to lift the gate with a paddle up .

[PaulJ]

35 minutes ago, Loddon said:

I was going to say maybe its boaters that don't understand how  guillotine gates work.

After all it is possible to lift the gate with a paddle up .

Oundle has a sensor in the paddles- its very fussy and even half a turn not fully down will stop you lifting the guillotine. Dont know about others.

For the Record-Havent actually personally tried lifting guillotines without dropping paddles first but an EA bod was telling me a great story about a very irate boater stuck in that lock 😀

[GUMPY]

 

Edited August 1, 2022 by Loddon

[enigmatic]

On 29/07/2022 at 08:01, Scholar Gypsy said:

No, I don't think that is the reason. 

 

To see why, imagine a stream of boats all day, downstream boats arriving on the hour and boats heading upstream arriving at 30 mins past. Let's also assume the gates make a perfect seal - they are better than many on the canals. 

 

With the normal mode of operation, with the boat heading upstream leaving the lock empty and the guillotine up, two lockfuls of water will be moved each hour from the upper reach to below the lock. 

With the new mode of operation,  only one lockful will be used, halving consumption. 

 

In practice, of course, the saving will be less than 50%, but it should still be significant (and will more closely match the consumption of the locks with  V doors at both ends).

 

PS I don't think Loddon's point is relevant here  as flows are so low.

 

This is the only logical interpretation of the notice: it's only addressed to upstream boaters and only mentions the guillotine so is basically a "don't waste water and your own time emptying the lock after you've used it" (afaik Loddon's point about the V gates being the lowest point is the reason they *normally* want the guillotines open when they're more concerned river levels might get too *high*)

 

Downstream boaters aren't addressed, so are presumably correct in continuing to leave the guillotine open which most seem to be doing. So Great Ouse rules, basically.

 

But Titchmarsh effectively has a rule of its own since a bloke in the MNCC gets cross if you don't shut both sets of gates.