How do Watford Staircase locks work?

[RAB]

Intrigued by the red and white paddles! Understand you open the red and then the white but do you have to wait for the water to reach a certain level before opening the white paddle , or a time, or just straight after? Also is it exactly the same whether your ascending or descending?

 

Never been on that part of the Grand union and saw a u-tube blog, but it wasn't clear. so my inquisitive mind is now pondering how it all works with the side pounds.

I did a quick search but didn't find anything directly answering my pondering's!

[adam1uk]

Red before white and you’ll be alright; white before red and you’ll wish you were dead.

 

It’s the same weather going up or down.  The red paddle takes water from the side pond into the lower lock, then the white paddle takes water from the next lock up and puts it in the side pond.  So if you do it the wrong way round, you could end up flooding the side pond.  It also means that when coming down, you wind the red paddle and nothing happens to the boat — that only starts moving when the white paddle is lifted.  The same system operates at Foxton.

[Bod]

Be aware both Watford and Foxton locks have opening hours, and are locked up outside these hours.

Arrive, moor up, find the Lockie with the list, they will tell you when to move, in busy times be prepared for a long wait, the best way of getting through in busy times is to help others through.

 

Bod.

[dmr]

I have thought about this a bit and I would like to know how Foxton and Watford work, and in particular how the sideponds actually save water.

The sideponds are not like a typical sidepond which is half filled from a full lock, instead Foxton works just like a standard staircase where water drains from one pound to the pound below......it just happens to do this via the sidepond. On most Foxton locks you can actually see this...the water rushes into the sidepond, does a quick U-turn and rushes back out into the chamber below.

 

I assume there must be some advatage when the flight turns from going up to gong down?  Maybe I need to draw a few little pictures, but I bet somebody here has already worked it all out 😀

[ditchcrawler]

It use to be possible in the winter month to work the flights your self, they only had keepers during the summer months, but still locked at night.

[Wanderer Vagabond]

9 minutes ago, dmr said:

I have thought about this a bit and I would like to know how Foxton and Watford work, and in particular how the sideponds actually save water.

The sideponds are not like a typical sidepond which is half filled from a full lock, instead Foxton works just like a standard staircase where water drains from one pound to the pound below......it just happens to do this via the sidepond. On most Foxton locks you can actually see this...the water rushes into the sidepond, does a quick U-turn and rushes back out into the chamber below.

 

I assume there must be some advatage when the flight turns from going up to gong down?  Maybe I need to draw a few little pictures, but I bet somebody here has already worked it all out 😀

Not sure about saving water but I would have thought without the side ponds the system would grind to a halt for boats going up. Going down is fine since you bring your water with you, but if the boat coming down leaves all of the locks empty, where are you going to get your water to fill them if you are going up, unless you go right to the top and run water down? 

[Rambling Boater]

https://canalrivertrust.org.uk/media/original/43877-foxton-locks-sign.pdf?v=4300aa

 

This is for Foxton, but not sure if there is a similar pdf for Watford.

 

With any staircase, if I'm going up  I check that all of the pounds above are 'up' (are full) except obviously the bottom one you are entering which must be empty.

 

If I'm going down, I check that all of the pounds are 'down' (empty) except the top one you are entering which must be full.

 

Well thats how I remember it.

 

From Wiki ;

 

"The locks are equipped with side pounds, with white paddles emptying a lock into a side pound, and red paddles filling the next lock downstream from the pound. This saves water compared to the more common riser staircases, since changing the direction of traffic does not require emptying/filling almost all the locks'

[davidg]

The sideponds at Watford & Foxton fulfil the role taken by the pounds which separate normal locks. They are not water saving sideponds at all. The difference is that you can't boat up and down them. Just think fill before empty as you would for a normal pound.

 

Edit: Just to clear up any ambiguity in "fill before empty", I meant fill the lock which draws water from the pound before you empty the lock which puts water in the pound. Same as you would for a pound you can boat along so the emtying water doesn't pour over the bywash, or overflow in this case.

Edited October 5, 2023 by davidg

[dmr]

3 minutes ago, davidg said:

The sideponds at Watford & Foxton fulfil the role taken by the pounds which separate normal locks. They are not water saving sideponds at all. The difference is that you can't boat up and down them. Just think fill before empty as you would for a normal pound.

 

But what do the sideponds do to help compared with a normal staircase? The various staircase flights on the L&L manage without sideponds.

[Wanderer Vagabond]

8 minutes ago, dmr said:

 

But what do the sideponds do to help compared with a normal staircase? The various staircase flights on the L&L manage without sideponds.

With a normal L&L staircase, such as Bingley 5 rise, you have to make sure all of the locks are full before you start up them, if they aren't you will run out of water and be unable to get over the cill to the next lock. If you had to do that at Foxton you'd be filling 10 9 locks. As the other poster suggested, the side pounds at Foxton serve the same purpose as the pounds between locks on non-staircases. I don't know what the limit is for boats going up in convoy, but I've gone up in a line of three without running out of water, there will however be some limit (obviously no limit to coming down).

Edited October 5, 2023 by Wanderer Vagabond

[dmr]

11 minutes ago, Wanderer Vagabond said:

With a normal L&L staircase, such as Bingley 5 rise, you have to make sure all of the locks are full before you start up them, if they aren't you will run out of water and be unable to get over the cill to the next lock. If you had to do that at Foxton you'd be filling 10 9 locks. As the other poster suggested, the side pounds at Foxton serve the same purpose as the pounds between locks on non-staircases. I don't know what the limit is for boats going up in convoy, but I've gone up in a line of three without running out of water, there will however be some limit (obviously no limit to coming down).

 

I really need to draw some pictures 😀 We did Foxton a few weeks ago and CRT were doing 5 up then 5 down, or maybe 6?  we had to wait for ages..

So if I follow another boat up all is well because there will always be a full lock in front of me? So its just on the turn around from going down to going up where there is a gain??? 

When we came down Watford the lockies were putting a lot of effort into getting the levels correct in the sideponds (due to leakage) but were unable/unwilling to explain what they were doing.

Came down the Droitwich recently and really good to see sideponds still in use. Up the Bratch tomoro.....thats another thing.

[David Mack]

The 'sideponds' at Watford and Foxton (and Bratch and a few other places) are just the same, in water usage terms, as the ordinary pounds between normal single locks. And so the amount of water used is the same as passing through the same number of single locks (without passing any boats travelling in the opposite direction). So for example if you arrive at the bottom of the locks and they are all empty, you will fill each lock in turn, won't empty any locks and leave them all full. So each sidepond will be one lockful down and you will have drawn one lockful from the upper pound. And the next boat through, whether travelling uphill or downhill will at some point need to empty the locks, which will replace the lockful of water in each side pond.

Staircase locks without these sideponds can only be filled from the lock above. So you ascend a flight of 5 such locks, all empty, you would have to draw 5 lockfuls of water from the upper pound, and the next boat through would empty all those 5 lockfuls into the lower pound. 

The sideponds save a significant amount of water. Which is why you generally only get 2 lock staircases without them, as the water consumption would be just too much for longer staircases.

[DShK]

I've recently noticed that there are locks on the GU which have side ponds which are not in use. I wonder what the reasoning is?

[David Mack]

10 minutes ago, dmr said:

Came down the Droitwich recently and really good to see sideponds still in use.

The sideponds on the top three locks at Hanbury are different. These are single locks, but pretty deep. When the Droitwich Junction Canal was restored the sideponds were also put back into use and boaters encouraged to use them to minimise the water take from the Worcester and Birmingham. Elsewhere BWB/CRT have taken the view that either the water saving is not needed or backpumping is more reliable. And it saves on sidepond maintenance.

6 minutes ago, DShK said:

I've recently noticed that there are locks on the GU which have side ponds which are not in use. I wonder what the reasoning is?

See above.

Also BW used to claim that the water saved by boaters using them properly was cancelled out by additional water lost by those who got it wrong. Not sure I really accept this. 

Edited October 5, 2023 by David Mack

[Wanderer Vagabond]

2 minutes ago, dmr said:

 

I really need to draw some pictures 😀 We did Foxton a few weeks ago and CRT were doing 5 up then 5 down, or maybe 6?  we had to wait for ages..

So if I follow another boat up all is well because there will always be a full lock in front of me? So its just on the turn around from going down to going up where there is a gain??? 

When we came down Watford the lockies were putting a lot of effort into getting the levels correct in the sideponds (due to leakage) but were unable/unwilling to explain what they were doing.

Came down the Droitwich recently and really good to see sideponds still in use. Up the Bratch tomoro.....thats another thing.

True, but you need to remember where that water has come from. For it to work the whole flight would need to be full before you started, but if the last boat coming through beforehand was going down, they wouldn't be (without the sideponds). Conversely, if the last boat was going up before a line of boats came down, you'd have to empty all of the locks before you set off from the top, or enjoy the 'entertainment' of washing the gongoozlers off the towpath as emptying each lock would then flood the lock below it (without the sideponds).

 

 

[dmr]

Just now, David Mack said:

The sideponds on the top three locks at Hanbury are different. These are single locks, but pretty deep. When the Droitwich Junction Canal was restored the sideponds were also put back into use and boaters encouraged to use them to minimise the water take from the Worcester and Birmingham. Elsewhere BWB/CRT have taken the view that either the water saving is not needed or backpumping is more reliable. And it saves on sidepond maintenance.

 

These are proper sideponds? Empty half a full lock into the sidepond, then half fill an empty lock from the sidepond. Also at Hanwell and Bosley (and others) but these no longer working? 

And a lock to lock option at Hillmorton

15 minutes ago, Wanderer Vagabond said:

True, but you need to remember where that water has come from. For it to work the whole flight would need to be full before you started, but if the last boat coming through beforehand was going down, they wouldn't be (without the sideponds). Conversely, if the last boat was going up before a line of boats came down, you'd have to empty all of the locks before you set off from the top, or enjoy the 'entertainment' of washing the gongoozlers off the towpath as emptying each lock would then flood the lock below it (without the sideponds).

 

 

 

Some staircases (Droitwich before the underpass for example) have a huge overflow so you can empty a full chamber into thew lower full chamber without causing a flood. Foxton has its overflows in the sideponds so you can still make a flood.....but you don't see it 😀.

I can see that the sideponds are a big timesaver because you can change direction without having to preset all the chambers (as long as the sideponds are big enough) but do they save any water???

[davidg]

And the overflows in the sideponds perform the same function as a normal lock bywash.

55 minutes ago, DShK said:

I've recently noticed that there are locks on the GU which have side ponds which are not in use. I wonder what the reasoning is?

 

I once strode up to the sidepond paddles on one lock somewhere up the fields after one of the kids on the camping boat asked me how they worked. I still have the chrome plated windlass I used with the cracked plating around the slight bend in the handle. No way was the paddle shifting.

 

Too much effort to maintain them.

Edited October 5, 2023 by davidg

[Mike Tee]

In answer to part of the original question, you raise the red paddle then immediately raise the white one - no wait necessary.

[matty40s]

10 hours ago, DShK said:

I've recently noticed that there are locks on the GU which have side ponds which are not in use. I wonder what the reasoning is?

Maintenance costs. There are 2 of the Hanwell flight where you can still just about use the paddles to see how it all worked. 

[magpie patrick]

11 hours ago, dmr said:

I have thought about this a bit and I would like to know how Foxton and Watford work, and in particular how the sideponds actually save water.

The sideponds are not like a typical sidepond which is half filled from a full lock, instead Foxton works just like a standard staircase where water drains from one pound to the pound below......it just happens to do this via the sidepond. On most Foxton locks you can actually see this...the water rushes into the sidepond, does a quick U-turn and rushes back out into the chamber below.

 

I assume there must be some advatage when the flight turns from going up to gong down?  Maybe I need to draw a few little pictures, but I bet somebody here has already worked it all out 😀

 

They save water compared to a conventional staircase, not compared to a conventional lock

 

Staircases are cheaper to construct than a flight, fewer gates and wing walls, and take less length so if you can find a suitable slope there is less earthworks required. However they use more water - Foxton and Watford are a compromise - the capital cost of a staircase and (roughly) the water consumption of a standard lock

11 hours ago, dmr said:

 

But what do the sideponds do to help compared with a normal staircase? The various staircase flights on the L&L manage without sideponds.

 But you have to fill every lock from the top

10 hours ago, dmr said:

 

These are proper sideponds? Empty half a full lock into the sidepond, then half fill an empty lock from the sidepond. Also at Hanwell and Bosley (and others) but these no longer working? 

 

 It might be something to while away a few hours to try and list all the locks that had sideponds! 

[Captain Pegg]

I wonder if perceived lack of need and low expectations of the average leisure boater’s capability to use them correctly is as much to do with side ponds falling into disuse as maintenance savings.

 

I can’t really remember any working 40+ years ago. It’s not a recent occurrence.

 

Hanbury - I believe the only properly working set on the network - may be a quirk of the restoration and I note that even the Volockies are not as insistent on their usage as they once were.

Edited October 6, 2023 by Captain Pegg

[Big Bob W]

14 hours ago, adam1uk said:

The red paddle takes water from the side pond into the lower lock, then the white paddle takes water from the next lock up and puts it in the side pond.

Isn't it the other way round?

Red Paddle empties the upper pound directly to the lower pound.

White paddle is to the side pond.

 

 

 

[nicknorman]

14 minutes ago, Big Bob W said:

Isn't it the other way round?

Red Paddle empties the upper pound directly to the lower pound.

White paddle is to the side pond.

 

No.

[David Mack]

45 minutes ago, Captain Pegg said:

I can’t really remember any working 40+ years ago. It’s not a recent occurrence.

I can remember finding the odd one still usable years ago, and using them with enthusiasm when we could. But there wasn't much point really in using half the water at just one lock in the middle of a flight!

[john6767]

20 minutes ago, Big Bob W said:

Isn't it the other way round?

Red Paddle empties the upper pound directly to the lower pound.

White paddle is to the side pond.

 

 

 

No. The paddles connect the locks direct to the side pound.  The red paddle connects to lower lock to the side pound, the white one the upper lock to the side pound.