Sluice for draining canal - advice please

[magpie patrick]

Canal related - we don't have a canal maintenance sub-forum though!

 

On the coal canal we are trying to rewater a short section, and we need to fit a sluice over an existing culvert to allow us to drain it.

 

A debate has arisen - a sluice frame and board are available, but one volunteer advises that this is not suitable as they aredesigned to act as a valve in a pipe, not an underwater cover over a culvert. Another volunteer is disputing this. Aside from a clash of egos the second volunteer is very averse to spending money and will do huge amounts of work rather than buy a new part. 

 

I can see there is a difference between a valve that is designed to close a pipe and a paddle over the end of one, but I don't know what it is or why they're not interchangeable. Does anyone here know? 

 

Thank you - you may be saving the society having to find another chairman! 

Edited December 23, 2021 by magpie patrick

[1st ade]

8 minutes ago, magpie patrick said:

I can see there is a difference between a valve that is designed to close a pipe and a paddle over the end of one, but I don't know what it is or why they're not interchangeable. Does anyone here know?

No more than engineering guesswork but: -

1. A valve to close a pipe needs to not breach the pipe - the mechanics are internal to the pipe, are worked externally but the fluid (whatever is is) mustn't escape
2. an element of directionality - you are presumably closing the culvert from the "wet" (canal) side so the pressure of the head of water in the canal will assist in sealing - if trying to close the end of a pipe and stop water getting out, the pressure will hinder rather than help
3. Debris - for your application make sure that debris in the canal can't prevent you from opening the sluice

A physical inspection of the sluice frame and board available (or photo's on this forum) might answer these points

[frangar]

Most canal overflow controls/opening sluices are paddles or a version of them operated by a rack. Now there may be better technical solutions now than 200 years ago but although there is the occasional failure…such as at barbridge a couple of years ago…in the main they seem to be fine. Like all paddle arrangements don’t expect them to be 100% leak free. 
 

Another advantage is they won’t be as susceptible to jamming with debris as a conventional gate type valve. You could always engineer some type of mini stop plank arrangement on the wet side in case servicing it is a concern…eg a couple of grooves to put a sheet of steel in or similar. 

[BEngo]

The simplest solution would be something like a bow thruster's fitment into the tube, or the drain arrangements for that Welsh aqueduct.

 

Raise a short vertical culvert from the existing one, to canal bed level.  Ensure it has a flat top face and raised edges

Fit a plate across the top face,  inside the raised edges so it does not slide off.   One of CRT's plastic paddles would be fine, or a slab of  2 inch elm board would be traditional.

 

Connect the board to the bank with some chain.

  

Fill canal  with water and wait for some passing dredger to pull the chain😁.

 

N

[Bee]

My thoughts are that a valve can (?) be attached to a pipe that can be shoved in a ditch or somewhere and needs only mimimal brickwork, the end in the canal should be fairly easy to fix with not too much brickwork too. A sluice arrangement sounds like a devil of a lot of brickwork to avoid washing everything away.

[Jen-in-Wellies]

Introduce some water voles. They'll soon have your canal drained. 😀

[1st ade]

1 hour ago, magpie patrick said:

we don't have a canal maintenance sub-forum though!

You've identified a serious omission - come on, a Mod is only one step down from the almighty!

[Pluto]

This was the standard type of drain plug used on the L&LC. It was easy to fit onto the wooden culverts which were often used for small water passages under the canal, but would need some form of connection between the frame and the culvert for more recent culvert designs. There is water pressure to overcome when opening, as this one has a winch fitted to the towpath wall to open it. The chain would be long enough to reach the towpath wall, where it could easily be retrieved, and a rope extension fitted which would then be wound around the winch. Such a system should be fairly cheap to install, and be difficult to vandalise, especially if the winch was made removable. Once fitted, it can be virtually ignored, unlike modern valves which need opening and closing routinely to ensure their operation.

[nebulae]

Some of the locks on the Montgomery canal were(and some still are) fitted with paddles in the bed of the canal. These slide rather than lift verticaly. As they have been in use for many years and seem to work O.K. ,perhaps you could adapt the idea .A chain as per Pluto"s picture woud open the paddle. If the section of canal was drained,then the paddle could be pushed back manualy.

[Ray T]

The Day They Pulled The Plug - Issuu

[Mike Todd]

There's one li9ke it in Manchester as well - cannot recall exactly but I did come across a video of it a few months back.

[Graham Davis]

On 23/12/2021 at 11:47, Pluto said:

This was the standard type of drain plug used on the L&LC. It was easy to fit onto the wooden culverts which were often used for small water passages under the canal, but would need some form of connection between the frame and the culvert for more recent culvert designs. There is water pressure to overcome when opening, as this one has a winch fitted to the towpath wall to open it. The chain would be long enough to reach the towpath wall, where it could easily be retrieved, and a rope extension fitted which would then be wound around the winch. Such a system should be fairly cheap to install, and be difficult to vandalise, especially if the winch was made removable. Once fitted, it can be virtually ignored, unlike modern valves which need opening and closing routinely to ensure their operation.

 

Something similar to that was fitted in the Worcester & Birmingham, around the top of the Worcester flight, and failed several years ago, draining a long section of canal. 
Allegedly it was made of wood and had finally rotted away, having been forgotten about.

[MtB]

On 23/12/2021 at 07:47, magpie patrick said:

Aside from a clash of egos the second volunteer is very averse to spending money and will do huge amounts of work rather than buy a new part. 

 

I would be willing to donate one of these if it helps:

[ditchcrawler]

8 minutes ago, MtB said:

 

I would be willing to donate one of these if it helps:

You know someone would pinch it, they always do

[MtB]

2 minutes ago, ditchcrawler said:

You know someone would pinch it, they always do

 

I remember when I was a brat, in one issue of "The Beano" Denis the Menace found a rope lying by the canal and trailing into the water. He gave it a massive pull and a giant plug turned out to be on the end. Then he turned around to see the last of the canal water disappearing down the hole and all the boats were stranded, DOH!

 

At the time I thought it was a rather stoopid and unlikely plot but now as a groan up I can see it was not so far from a real possibility!

 

This must have been in about 1963.

[Squires]

Slightly off subject. I was reading about the caison locks trialed on the Somerset coal canal. Crazy or what?

[magpie patrick]

On 25/12/2021 at 19:52, Squires said:

Slightly off subject. I was reading about the caison locks trialed on the Somerset coal canal. Crazy or what?

 

Completely stark staring bonkers is probably a better description - even the most rudimentary of risk assessments would declare the caisson lock a death trap, unfortunately the managing committee didn't think of this before getting on board a boat to go through it - we know the boat jammed, we know they were rescued, but we don't know how.

The flotation tank concept was adopted at other lifts much later on, such as Henrichenberg, but they weren't daft enough to put the boat and crew inside the flotation tank. 

[Pluto]

1 minute ago, magpie patrick said:

 

Completely stark staring bonkers is probably a better description - even the most rudimentary of risk assessments would declare the caisson lock a death trap, unfortunately the managing committee didn't think of this before getting on board a boat to go through it - we know the boat jammed, we know they were rescued, but we don't know how.

The flotation tank concept was adopted at other lifts much later on, such as Henrichenberg, but they weren't daft enough to put the boat and crew inside the flotation tank. 

The two Henrichenburg and the single Rothensee lifts all used floatation tanks as the stability of the foundations was uncertain, because of mining for Henrichenburg, and as it was built on the Elbe flood plain for Rothensee. There have been more recent designs for encased tanks, such as proposed on the Somerset Coal Canal which were more realistic. Another similar scheme was for an inclined tunnel carrying a canal through the Alps, with boats moved on a wedge of water, as per the two inclines at Fonserannes and  Montech, but completely within the tunnel.

[magpie patrick]

2 minutes ago, Pluto said:

The two Henrichenburg and the single Rothensee lifts all used floatation tanks as the stability of the foundations was uncertain, because of mining for Henrichenburg, and as it was built on the Elbe flood plain for Rothensee. There have been more recent designs for encased tanks, such as proposed on the Somerset Coal Canal which were more realistic. Another similar scheme was for an inclined tunnel carrying a canal through the Alps, with boats moved on a wedge of water, as per the two inclines at Fonserannes and  Montech, but completely within the tunnel.

 

Presumably you mean they didn't risk suffocating the occupants? 

[Pete of Ebor]

On 23/12/2021 at 15:58, Mike Todd said:

There's one li9ke it in Manchester as well - cannot recall exactly but I did come across a video of it a few months back.

Would it be this one...

 

[Mike Todd]

That's the one.

[magpie patrick]

On 30/12/2021 at 10:40, Pete of Ebor said:

Would it be this one...

 If you know in advance you will need to drain the canal and also can remember where you out the plug (the chain will inevitably have gone missing or fallen in) then these things work well - I wouldn't want to use one to drain the canal at short notice though

[Pluto]

I have found more details about the inclined tunnel lock, first the patent, and then a drawing. The scheme was proposed around 1905 by Pietro Caminada.

[magpie patrick]

That looks nearly as frightening as the caisson lock! 

[David Mack]

2 hours ago, Pluto said:

I have found more details about the inclined tunnel lock, first the patent, and then a drawing. The scheme was proposed around 1905 by Pietro Caminada.

A similar concept to the late Terry Fogarty's diagonal lock.

https://web.archive.org/web/20170208213301/http://www.diagonallock.org/