Drained pond

[dominicebs]

Really dumb question but thought I woudl just check. The otehr day someone had drained the pond at the bottom lock of a flight of 3. They had doen this by leaving the side pond sluice open whilst opening the top sluices.

 

Am I right in assuming that to re flodd the drained pond you simply fill and drain the 2 locks uphil from there - making sure that you do both so you dont simply refil the bottom pond by emptying the middle one.

 

I am also assuming that rather than just open up everything uphill from the drained pond it is better to fil a lock / shut it then drain it downhill etc.

 

As i say a dumb question but just wanted to make sure so if ever I encounter this again I am doing the correct thing

[Mike Tee]

As I understand it, best practise is to leave all the gates shut, and open paddles at both ends of the lock. This prevents possible damage to the bottom gates, and gives you more control over the flow of water. I know its probably a stupid reminder, but if someone has left paddles up to drain the pound, don't forget to drop them before trying to refill it. And if its in a flight, they've probably done it to the next lock down.

[Graham Davis]

Quickie.

 

They are pounds not ponds

 

If we've had to do it, we've done it Mike's way.

[nicknorman]

Quickie.

 

They are pounds not ponds

And that difference is significant - pound = bit of canal between 2 locks. Pond (especially side pond) = a separate body of water that can be connected to a lock via some sort of paddle / sluice, used in the "good old days" as a water-saving measure and typically at a level that is half way up the lock. So Bratch has (side) pounds between the locks whereas Foxton has side ponds. I think??

[Paul C]

So Bratch has (side) pounds between the locks whereas Foxton has side ponds. I think??

 

Yep, except to say that Bratch's pounds are bizarre in that they vary in level quite significantly, and are too short to pass another boat in. So its not the best example of a "normal" pound. A normal pound is the bit of canal in between a lock, which is designed to one level (but may vary a little - and be okay to use at slightly differnet levels, or might not) and in 99% of cases boats can pass in a pound, meaning that locks can be approached in a 'normal' fashion in that all you need to be concerned about is the level of the next pound beyond the next lock; and whether there is a boat in this pound (or just about to be in the pound, ie nearly finished their lock) so you'd give them the lock, if the level of the lock was in their favour, for water-conservation reasons.

 

The exceptions I can think of off the top of my head are Bratch 3 where the pounds are both too short to pass a boat; and their water level needs managing by the timing of filling/emptying the locks they ajoin. Stourbridge flight has a similar pair of locks so close together you can't pass a boat in. Stourton 4, in between the 1st and 2nd, has a short pound but its possible to wiggle around if the boat is <70ft. Some other lock pounds are so short that while in theory 70ft boats can pass, in practice its a pain to do (Titford 6, Hurleston pound between the top 2 locks, for example) but this isn't particularly rare. Black Delph, and other flights (I'm sure someone can name more) require a bit of management in the water levels because if you emptied each lock (ie coming down) before filling the next, you'd send so much water down as to flood the lowest pound. So you fill the next lock during/before emptying the current one, going down. But then some people say you should always do that.

PS I believe that side ponds are virtually extincy now, but there's some on the Droitwich canal (the narrow bit) - however because its a flight of 3, and only 2 out of the 3 side ponds were working, it messes up the water levels and you may as well not bother with them at all (no water saving in using them then readjusting the level of the pounds, to get through without grounding etc).

[nicknorman]

Yes I cited Bratch not because it has typical pounds between the locks - far from it! - but rather it has (side) pounds that look like side ponds at first glance, but there is a difference...

[Tacet]

Really dumb question but thought I woudl just check. The otehr day someone had drained the pond at the bottom lock of a flight of 3. They had doen this by leaving the side pond sluice open whilst opening the top sluices.

 

 

I am not sure quite what you mean; conventionally (always?) you can't drain the pond/pound below the bottom lock - unless it is not the err... bottom lock. (Edit: perhaps you mean the pound above a bottom lock)

 

Anyway, as others have said, an empty pound is normally remedied by running water down from above, through the paddles whilst the gates are shut. You need to have some thought as to the effects on others boats etc in the pound(s) from which you intend borrowing water - so it is often good practice to only refill to a minimum level. In a flight of locks with (normally) equal rises, the passage of boats will lead to normal levels, eventually - all other things being equal.

 

Some boaters prefer to ring CRT - but I have yet to see its operatives arrive with a tanker of water.

Edited June 25, 2014 by Tacet

[billh]

Quickie.

 

They are pounds not ponds

 

 

The Canalmen of olden days when I were a lad always referred to pounds as ponds round here , eg the "Acid Pond" was on the Ashton Canal between locks 7 and 8 , included the short Clayton Arm where Hardman & Holden's chemical works was situated. even more delightful was the "Bonework's Pond" between 12 and 13.....

To digress somewhat, it was said that you could tell where you were on the canal with eyes shut by the smell which went between extremes, from the obnoxious Victor Wolf's Fatty Acids plant (lock 9) or the Manchester Corporation manure works(lock 4) to the rather nice Robertson's Golden Shred marmalade factory on the summit pound (I mean pond)

[Purple Fairie]

We went up the Northampton arm last Friday (17 Locks in total, the top 13 being in a flight) and some 'kind' soul left every top paddle and gates open from lock 12 through to lock 1, resulting in 4 drained pounds in a row!! It's only the top gates that are watertight on the arm so the whole lot just 'went'.

There is an infamous low pound anyway, but this just emptied it, and I'm pleased that we came across it rather than on someones first go as this would have put them off for life! Luckily we've done the arm a couple of dozen of times since moving here last year, so we did manage to sort it and still only be 1/2 hour behind schedule

[Tuscan]

Two boats came past us this evening on Atherstone flight one a hire boat , one going to Braunston show can't remember which order. However took dogs out and our pound was going down top gates of 9 & 10 open, closed gates and lock 9 emptied through the leaky gate in 20 minutes.

[dmr]

I believe the official CaRT method of filling a drained pound is to close both gates and then open just one top paddle and one bottom paddle. At first I suspected this was a time waste working practice but have since been told that it avoids stirring up too much silt and rubbish from the bottom of the pound/lock. Closing both gates also reduces the likelihood of flushing rubbish onto the cill.

We made this mistake last year on the Digbeth flight and did indeed get a bike onto the cill which prevented the gate from closing.

 

If its a really mucky canal it might be worth only opening the paddles half way.

 

..........Dave

[ditchcrawler]

I believe the official CaRT method of filling a drained pound is to close both gates and then open just one top paddle and one bottom paddle. At first I suspected this was a time waste working practice but have since been told that it avoids stirring up too much silt and rubbish from the bottom of the pound/lock. Closing both gates also reduces the likelihood of flushing rubbish onto the cill.

We made this mistake last year on the Digbeth flight and did indeed get a bike onto the cill which prevented the gate from closing.

 

If its a really mucky canal it might be worth only opening the paddles half way.

 

..........Dave

So what happens when you fill a lock, you fully draw both paddles then and on lots of locks the water cascades in.

[Scholar Gypsy]

I believe the official CaRT method of filling a drained pound is to close both gates and then open just one top paddle and one bottom paddle. At first I suspected this was a time waste working practice but have since been told that it avoids stirring up too much silt and rubbish from the bottom of the pound/lock. Closing both gates also reduces the likelihood of flushing rubbish onto the cill.

We made this mistake last year on the Digbeth flight and did indeed get a bike onto the cill which prevented the gate from closing.

 

If its a really mucky canal it might be worth only opening the paddles half way.

 

..........Dave

 

I was told this too by a very friendly and helpful C&RT lengthsman on the Northampton arm a couple of months ago. The risk is of flushing silt onto the cill of the bottom gates, making them hard to open.

 

It is of course very dangerous to run water through a lock without the gates being shut. If the gate moves a bit (or a helpful passerby leans on the balance beam) then it will slam shut, with risk of damaging the gate or knocking for six anyone standing in the way...

[dominicebs]

Thank you - so, pedantry aside, its open up one top one bottom paddle leaving gates shut

[NickF]

Must admit I have always shut all gates and opened all paddles when I have had to do it. I suppose this could stir up the silt in the pound below the lock which is presumably empty or nearly empty. May be i'll just do one next time.