Jump to content

Hall Green Stop Lock


magpie patrick

Featured Posts

I've just spent a day or so on Lutine, finally preparing her for the long journey south. She is moored at Scholar Green, so I had a walk down to Hall Green Stop Lock, which had a fall of about a foot from the Macclesfield Canal to the Trent and Mersey Canal.

 

First, as most people I'm sure know, it is at the junction even though it's about a mile from the main line of the T&M. For reasons that have variously been thought of as astute or paranoid the T&M built branches to connecting waterways rather than allowing a junction direct to the main line (thinking about it, this a slight overstatement - they built branches to connect to the Macc and the SU Middlewich branch. For complicated reasons they also built five miles of the Coventry Canal but I digress...)

The lock can be seen here...

 

Lutine and Hall Green 007.JPG

 

The gate arrangement is odd and has been discussed before - twin top gates and a single leaf bottom gate. What has also been commented on before is the astonishingly long structure. From the upper wing wall to the lower wing wall is about 270 feet, the structure being a bare 7 feet wide for about 240 feet. the operational lock is a standard 70 feet or so (84 feet from gate hinge to gate hinge)

 

In the long length below the lock the following recesses can be seen

 

Lutine and Hall Green 017.JPG

 

These appear to be a pair of gate recesses for gates pointing towards the Trent and Mersey Canal, and are about 40 feet downstream of the bottom gate

 

also

 

Lutine and Hall Green 019.JPG

Much more overgrown but another gate recess about 80 feet downstream of the first pair. There is evidence of a similar recess on the towpath side but it is obstructed, and the light was failing so it was difficult to photograph The size of the two would again indiacte a pair of gates. The naked eye can pick out that the left hand edge (the edge nearest the present lock) is curved, again indicating gates pointing towards the T&M.

 

Finally, for this post at least, the sharp eyed may have noticed a bywash on the left of the first picture - this is the other end of it, to the right of this picture.

 

Lutine and Hall Green 021.JPG

 

So, obviously a lock and obvious (to me at least) not often used and not used for a long time if ever. Does anyone know anything of it's operation or function beyond the obvious? And why not build a single chamber with two sets of gates?

Edited by magpie patrick
  • Greenie 1
Link to comment
Share on other sites

I've just spent a day or so on Lutine, finally preparing her for the long journey south. She is moored at Scholar Green, so I had a walk down to Hall Green Stop Lock, which had a fall of about a foot from the Macclesfield Canal to the Trent and Mersey Canal.

 

First, as most people I'm sure know, it is at the junction even though it's about a mile from the main line of the T&M. For reasons that have variously been thought of as astute or paranoid the T&M built branches to connecting waterways rather than allowing a junction direct to the main line (thinking about it, this a slight overstatement - they built branches to connect to the Macc and the SU Middlewich branch. For complicated reasons they also built five miles of the Coventry Canal but I digress...)

 

The lock can be seen here...

 

attachicon.gifLutine and Hall Green 007.JPG

 

The gate arrangement is odd and has been discussed before - twin top gates and a single leaf bottom gate. What has also been commented on before is the astonishingly long structure. From the upper wing wall to the lower wing wall is about 270 feet, the structure being a bare 7 feet wide for about 240 feet. the operational lock is a standard 70 feet or so (84 feet from gate hinge to gate hinge)

 

In the long length below the lock the following recesses can be seen

 

attachicon.gifLutine and Hall Green 017.JPG

 

These appear to be a pair of gate recesses for gates pointing towards the Trent and Mersey Canal, and are about 40 feet downstream of the bottom gate

 

also

 

attachicon.gifLutine and Hall Green 019.JPG

 

Much more overgrown but another gate recess about 80 feet downstream of the first pair. There is evidence of a similar recess on the towpath side but it is obstructed, and the light was failing so it was difficult to photograph The size of the two would again indiacte a pair of gates. The naked eye can pick out that the left hand edge (the edge nearest the present lock) is curved, again indicating gates pointing towards the T&M.

 

Finally, for this post at least, the sharp eyed may have noticed a bywash on the left of the first picture - this is the other end of it, to the right of this picture.

 

attachicon.gifLutine and Hall Green 021.JPG

 

So, obviously a lock and obvious (to me at least) not often used and not used for a long time if ever. Does anyone know anything of it's operation or function beyond the obvious? And why not build a single chamber with two sets of gates?

 

This might explain it.

http://www.macclesfieldcanal.org.uk/hallgreen.htm

Link to comment
Share on other sites

 

Thanks

 

I'd worked out the lock working both ways, and the "jealous" or at least, "careful" canal companies.

 

Other companies didn't go quite so mad though, this was the arrangement where the Warwick and Birmingham joins the Digbeth Branch at Warwick BarIMG_9062.JPG

 

That's come out a bit big! one chamber, gates pointing both ways, whereas Hall Green is over twice the length of a conventional lock.

 

Interesting to note that both lock keepers cottages (I'll venture they were actually toll-keepers, one for each company) are next to the lock that is used now - clearly that's where they expected the action to be, and also shows the two companies could cooperate up to a point. So why not over having just one lock?

Edited by magpie patrick
Link to comment
Share on other sites

Maybe the relationship and co-operation was bad so they needed their own locks, and one company built the cottage where it is so they could work their own lock and keep a close eye on the other one????.

Are there any historic accounts of how strictly stop locks were guarded and managed?

Are they something the owners installed and then did not bother with too much, or did the lock keepers agressively police them???

I fear a lot of history has got lost.

 

................Dave

Link to comment
Share on other sites

This is the top of Johnsons Hillock, where the Lancaster met the L&LC. The extra rebate was for gates controlled by the L&LC so they could stop their water from feeding the Lancaster if necessary. There are similar recesses at the top of Wigan locks. Building a whole extra lock does seem a bit excessive.

gallery_6938_1_88430.jpg

Link to comment
Share on other sites

Pluto, what's the paddle on the right for?

 

I knew of the arrangement at Johnson's Hill, but not at Wigan, presumably the reverse applied there. It must be said if those second set of gates at either location had ever been used trade would have been well stuffed!

 

Dave (dmr) that's a fair point, I've no evidence for it but suspect the T&M would probably have been happier if the Macclesfield had remained unbuilt, as it provided an alternative route to/from the east side of Manchester. Of course in practice they got a heck of a lot of trade off the Macc.

 

Richard West, do you know anything more behind the page you cited? I hadn't picked up on the two cottage thing until you posted that.

Link to comment
Share on other sites

Pluto, what's the paddle on the right for?

 

I knew of the arrangement at Johnson's Hill, but not at Wigan, presumably the reverse applied there. It must be said if those second set of gates at either location had ever been used trade would have been well stuffed!

 

Dave (dmr) that's a fair point, I've no evidence for it but suspect the T&M would probably have been happier if the Macclesfield had remained unbuilt, as it provided an alternative route to/from the east side of Manchester. Of course in practice they got a heck of a lot of trade off the Macc.

 

Richard West, do you know anything more behind the page you cited? I hadn't picked up on the two cottage thing until you posted that.

 

Sorry, I don't know any more. I just remembered that I'd seen it when checking up on the Macc for our holiday earlier this year.

Link to comment
Share on other sites

This is the top of Johnsons Hillock, where the Lancaster met the L&LC. The extra rebate was for gates controlled by the L&LC so they could stop their water from feeding the Lancaster if necessary. There are similar recesses at the top of Wigan locks. Building a whole extra lock does seem a bit excessive.

gallery_6938_1_88430.jpg

It provides a feed down the flight, especially as you can see it is just cracked open in the photo. Wigan flight used a lot of water, especially as mining subsidence took hold. The top lock had a fall of 15 feet 6 inches in the late 19th century, and the locks, particularly on the upper section of the flight, had to be equalised on several occasions to reduce water usage. This photo shows the stones which have been inserted to raise the top lock.There were water depth marks on the stone, and they can still be seen, but with a gap where indicated here.

gallery_6938_1_102772.jpg

Link to comment
Share on other sites

Lock gates at junctions with other waterways were there to protect the loss of water from the earlier of the two, hence the arrangement at Horseleyfields, Wolverhampton, BCN. Wyrley & Essington. That at Digbeth was similar, but that arrangement was made when the Birmingham & Warwick Junction canal was opened. Lock drawings at Warwick Records Office assisted BW with the reconstruction of these gates a few years ago.

 

Ray Shill

Link to comment
Share on other sites

Thank Ray, interesting debate really on what purpose stop locks actually served

 

Of the four that still operate, Three fall from the newer canal to the older one (although in the case of Hawkesbury both canals were planned at the same time whilst Autherly falls from the older to the newer one.

 

Given the amount of water these locks consume, having a drop of only a few inches, I guess the direction of fall was a matter of technical convenience rather than protection, but actually, in the even of a breach, the downstream side isn't protected as the head will quickly reverse.

 

I also seem to recall that Hawkesbury only ended up with a fall at all because they got the levels wrong? That may be a myth though...

Link to comment
Share on other sites

This was the lock proposed in 1905 at Leigh between the L&LC and the Bridgewater. Because of mining subsidence, and the way the two canals were controlling this, there was the possibility that one canal would end up higher than the other, hence the double gates.

gallery_6938_1_14710.jpg

Link to comment
Share on other sites

  • 7 years later...

Sorry to bump what is such an old post, but I've had questions about Hall Green that I still haven't quite fully found a good answer to. Some of the confusion may be how terms are being/have been used (is the "stop lock" the water in between either of the gates, or just the "down" gate on either lock?). But, just to describe the setup in the overly-long chamber from north to south you had a set of pointed gates, then a single gate, then a small gap in between, then another single gate, and then another single gate at the entrance to the T&M side? Did I get that correct?

 

From the various pieces I've read on this, it seems that the purpose was originally to keep the Macclesfield slightly higher to 'protect' the T&M Hall Green branch. And, if that was the case, the Macclesfield lock really just functioned as a lift lock. Anyone have any of the original documentation organizing the development of the canal? The Macclesfield website seems to at least imply that any lock where the two met was simply to prevent water loss from the T&M. But then you see mentions all over that "either canal could be higher." This seems to skip right over in time the explanation for the development and purpose of the T&M lock. But we know that it was needed for one reason or the other, so I guess them both functioning as lift locks would make sense.

 

To end, a boat traveling "down" the from the Macclesfield would be locked down into the Macclesfield lock, and then in the chamber the three other gates would simply be opened - after they paid their toll to T&M - to allow passage? Is it that simple? Would kind of like to see someone make a little diagram describing how this setup worked.

Link to comment
Share on other sites

If the Macclesfield level was higher you would lock down through the Macclesfield lock then pass straight through the T&M lock, and vice versa if the T&M was higher. Either way the only water transfer between the two would be a very shallow lockful. Without the stop locks there would be uncontrolled (and unquantified) flow either way.

Link to comment
Share on other sites

Stop locks were found at most places where one canal company met another so that the canal with the higher water level could protect its water if there was any disagreement. There was usually some mention of restrictions or control of water in the Act under which a stop lock was built. This is the one at Johnsons Hillock on the L&LC, where the locks were built and owned by the Lancaster Canal Company, but the Leeds & Liverpool had control of an extra set of gates, now removed. You can still see the L&LC gate recess, which became unnecessary when the L&LC leased the southern Lancaster in 1864. When they were serviceable, I expect the L&LC stop gates were left open and the Lancaster's lock was operated as normal.

There was a second lock house part way down the flight, which could have been built by the Lancaster, while the one in the photo was built by the L&LC for their man to control passage through the top lock.

8153 general view from above.jpg

Link to comment
Share on other sites

13 hours ago, David Mack said:

If the Macclesfield level was higher you would lock down through the Macclesfield lock then pass straight through the T&M lock, and vice versa if the T&M was higher. Either way the only water transfer between the two would be a very shallow lockful. Without the stop locks there would be uncontrolled (and unquantified) flow either way.

 

Right, I understand the basic purpose, and that would exmplain why the T&M manuevered to have the new Macclesfield install a stop gate, but doesn't explain the reason for then building their own stop backed right up to it, except for obvious redundancy in case something happened to the Macclesfield stop gate. And, maybe, the explanation it's just that simple (redundancy).

 

But, as has been discussed, this was a very unusual setup. We're talking two chambers with four sets of doors in which both locks could act as lift locks; in fact, it seems arguable that that was their primary function. Typically, these canal junctions would only have two doors, correct? I think the other thing is that when we're talking about a "lock" we're usually talking a pound enclosed by two sets of doors to provide a rise/fall, whereas a "stop lock" is just a gate, right?

 

1.png

Edited by Kingsford
Link to comment
Share on other sites

8 hours ago, Kingsford said:

 

 

But, as has been discussed, this was a very unusual setup. We're talking two chambers with four sets of doors in which both locks could act as lift locks; in fact, it seems arguable that that was their primary function. Typically, these canal junctions would only have two doors, correct? 

 

 

 It is not that unusual for stop locks to have four sets of gates - the one at the junction of the Ashby Canal with the Coventry did for example, what is unusual here is the double chamber. 

 

Edited to add, the stop lock at the other end of the Macc, in Marple, had four sets of gates so either canal could be lower than the other.

 

You should also note that as built the summit level of the T&M was approximately level with the Macc - at some point the T&M was lowered by about a foot as mining subsidence had reduced headroom through Harecastle Tunnel (and increased depth!) This means the purpose of the structure is less obvious.

 

The term "stop lock" refers to a lock that is intended to control the flow of water between canals - they tend to be shallow although lock 20 on the Stratford Canal, which for a couple of centuries was the junction between it and the Grand Union/Warwick and Birmingham, is around 6 feet deep - the W&B had a right to full lock full of water with every boat, and this lock ensured they got it (and no more)

Link to comment
Share on other sites

9 hours ago, Kingsford said:

 

But, as has been discussed, this was a very unusual setup. We're talking two chambers with four sets of doors in which both locks could act as lift locks; in fact, it seems arguable that that was their primary function. Typically, these canal junctions would only have two doors, correct? I think the other thing is that when we're talking about a "lock" we're usually talking a pound enclosed by two sets of doors to provide a rise/fall, whereas a "stop lock" is just a gate, right?

 

1.png

The setup comprises two locks of conventional form except the rise is very small. The key point is that they face in opposite directions.

Most canal stop locks consist of two sets of gates.

Link to comment
Share on other sites

9 hours ago, Kingsford said:

(Snipped)

I think the other thing is that when we're talking about a "lock" we're usually talking a pound enclosed by two sets of doors to provide a rise/fall, whereas a "stop lock" is just a gate, right?

 

MP describes them well. But I have never considered a 'pound' to be the water between a set of gates at either end of a lock. Whilst when a set of gates are open, the water within the lock is 'part' of a pound, but when closed at both ends it is just a lockful of water taken from the upper pound to raise/lower craft.

 

A Stop lock has gates both ends, and the rise is usually small. But a Stop lock cannot be just a single gate across a waterway, as you would need to lower the entire pound to pass through, wasting much water in the process. However, where single gates are installed, it is usually either side of an aqueduct, and in one case I have seen - a tunnel, which are correctly called Stop Gates, designed to be closed, or automatically closed by water flow, in the event of a breach.

Link to comment
Share on other sites

18 minutes ago, Derek R. said:

But I have never considered a 'pound' to be the water between a set of gates at either end of a lock

What we now regard as normal locks are also known as 'pound locks', to distinguish them from 'flash locks' on rivers which were effectively just a single gate. 

But flash locks only work on rivers where there is a continuous source of water.

 

Link to comment
Share on other sites

16 minutes ago, David Mack said:

What we now regard as normal locks are also known as 'pound locks', to distinguish them from 'flash locks' on rivers which were effectively just a single gate. 

But flash locks only work on rivers where there is a continuous source of water.

 

Apart from Dutton Lock, which was effectively a flash lock when reduced to a single gate.

 

Two sets of gates were provided at stop locks where the difference in level was small, and would face opposite directions so the lock could continue to be used should there be a breach. That was the problem with the single gate at Dutton, which cause problems when the Bridgewater breached in 1972. The balance beam had a rather bent appearance after Jack Tolley went through.

Link to comment
Share on other sites

1 hour ago, magpie patrick said:

 It is not that unusual for stop locks to have four sets of gates - the one at the junction of the Ashby Canal with the Coventry did for example, what is unusual here is the double chamber. 

 

Edited to add, the stop lock at the other end of the Macc, in Marple, had four sets of gates so either canal could be lower than the other.

 

You should also note that as built the summit level of the T&M was approximately level with the Macc - at some point the T&M was lowered by about a foot as mining subsidence had reduced headroom through Harecastle Tunnel (and increased depth!) This means the purpose of the structure is less obvious.

 

The term "stop lock" refers to a lock that is intended to control the flow of water between canals - they tend to be shallow although lock 20 on the Stratford Canal, which for a couple of centuries was the junction between it and the Grand Union/Warwick and Birmingham, is around 6 feet deep - the W&B had a right to full lock full of water with every boat, and this lock ensured they got it (and no more)

 

48 minutes ago, David Mack said:

The setup comprises two locks of conventional form except the rise is very small. The key point is that they face in opposite directions.

Most canal stop locks consist of two sets of gates.

 

Thanks, everyone, for helping me understand what was - and wasn't - unusual about this particular lock. BTW, what are some scenarios in which the T&M would have been higher than the Macclesfield? Just regular weather events, leakages, etc?

 

David, from an old drawing I've seen, the T&M's north/south or up/down lock gates were just single gates and didn't "point" in either direction. The only pointed set of gates seems to have been the northern gates of the Macclesfield stop lock.

Link to comment
Share on other sites

3 minutes ago, Pluto said:

Apart from Dutton Lock, which was effectively a flash lock when reduced to a single gate.

 

Two sets of gates were provided at stop locks where the difference in level was small, and would face opposite directions so the lock could continue to be used should there be a breach. That was the problem with the single gate at Dutton, which cause problems when the Bridgewater breached in 1972. The balance beam had a rather bent appearance after Jack Tolley went through.

 The junction of the Moira cut and the Coventry Canal being an example. Sadly, cottage and gates long gone.

Photo from CRT Archive. MB Rocket with the Barrett Family in charge.

MB Rocket.jpg

Link to comment
Share on other sites

3 minutes ago, Kingsford said:

David, from an old drawing I've seen, the T&M's north/south or up/down lock gates were just single gates and didn't "point" in either direction. The only pointed set of gates seems to have been the northern gates of the Macclesfield stop lock.

By "point" I mean that the gates open in one direction only, and can therefore only support a difference in water level only one way (whether a single gate or a pair of mitre gates). So if the Macclesfield level is higher, one or other of the Macclesfield gates/pair is holding the level difference, and the T&M gates both have equal water levels either side, and vice versa if the T&M is higher.

11 minutes ago, Kingsford said:

what are some scenarios in which the T&M would have been higher than the Macclesfield? Just regular weather events, leakages, etc?

Since the junction is at the bottom level of the Macclesfield Canal, occasions when the Macclesfield was lower than the T&M must have been infrequent. But the T&M lock would have protected the T&M in the event of leakage on the Macc, or a breach or even draining of the Macc for maintenance.

Link to comment
Share on other sites

There were several other types of safety gate which were expected to close automatically if there was a breach. On the L&LC, they were similar to lock gates, but without a balance beam. Brindley, and some other canal engineers, tried ones that folded up from the bottom. This drawing is from Maillard's book on canal engineering, with an example at Red House Bridge, on the southern section of the Lancaster.

100 safety gates.jpg

Adlington, Red House Bridge  68, showing stop gate stonework.jpg

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.