Stop Lock

[William Martin]

"Graham Palmer lock on the restored length of the Montgomery Canal has a very small rise/fall similar to a stop lock. It was introduced to allow for the ground levels having sunk since the canal was abandoned. Again, not a stop lock.."

 

 

That is interesting because it demolishes my original idea - clearly it was cheaper to add a lock than change the levels. What is the difference in levels?

[JohnO]

to quote jim sheads glossary

Stop Lock - A lock provided to protect the water supply of one canal company from another rather than to affect a significant change in the level of the waterway.

[Hairy-Neil]

What is the difference in levels?

 

Is around a foot.

 

I did a camp and a couple of weekends when WRG rebuilt the Aston flight some years ago, though I mostly worked down on lock three. I remember the top lock was altered accordingly, the height of the walls being reduced during the work.

Edited September 15, 2006 by Hairy-Neil

[roger]

to quote jim sheads glossary

Stop Lock - A lock provided to protect the water supply of one canal company from another rather than to affect a significant change in the level of the waterway.

 

Time to re categorise!!! 'Stop' locks - No difference in level at all. 'Go' locks - small difference in level! On some canals such as Hall Green we would have had both stop n' go locks! Now which was the stop and which was the go???

[John Orentas]

Time to re categorise!!! 'Stop' locks - No difference in level at all. 'Go' locks - small difference in level! On some canals such as Hall Green we would have had both stop n' go locks! Now which was the stop and which was the go???

 

 

Why don't we simply accept Jim Sheads definition. It doesn't require further interpretation.

[roger]

Why don't we simply accept Jim Sheads definition. It doesn't require further interpretation.

 

You're defintely not on a 'go' then!

[Timleech]

I've just come across this old thread, & would like to make a couple of points about Dutton stop lock.

 

First, the levels were more equal some years ago, as for some years the Bridgewater was maintained at a higher level to facilitate the Kellogs grain traffic through Trafford Park. At that time, I'm told that British Waterways did decide to remove the gates altogether (circa 1960, I believe). They quickly found that it was a bad mistake, as there was too much variation in levels at Middlewich.

With the lock in place, the Bridgewater level at Dutton/Preston Brook can drop by 5 or 6 inches if there's a strong W or SW wind for a couple of days. This is caused by the action of the wind on the water surface, blowing the water away to Manchester and Wigan. If you extend the pound right through to Middlewich, that effect will be increased, and that was indeed found to be the case. Also 6 inches drop on the T&M is much more significant than 6 inches on the deeper Bridgewater. Because the difference in levels at the lock was usually very small, a single top gate was fitted with a very long beam and extremely large paddle. This enabled the lock to be used as, in effect, a Flash lock.

The end of the Kellogs traffic more or less coincided with the very bad breach at Bollington (1971?), after which MSC became cautious about their water levels and maintained the Bridgewater on average several inches lower than the T&M. The lock then became difficult/unsafe to use with the single gate, so new bottom gates were made (by MSC Co!) and fitted.

Those who advocate removing the lock should think back to a much more recent time, when a failed paddle in Manchester led to the Bridgewater dropping by a couple of feet. The stop lock protected the T&M entirely, without it every boat between Dutton and Middlewich would have been on the bottom.

 

Tim

[fender]

I've just come across this old thread, & would like to make a couple of points about Dutton stop lock.

 

First, the levels were more equal some years ago, as for some years the Bridgewater was maintained at a higher level to facilitate the Kellogs grain traffic through Trafford Park. At that time, I'm told that British Waterways did decide to remove the gates altogether (circa 1960, I believe). They quickly found that it was a bad mistake, as there was too much variation in levels at Middlewich.

With the lock in place, the Bridgewater level at Dutton/Preston Brook can drop by 5 or 6 inches if there's a strong W or SW wind for a couple of days. This is caused by the action of the wind on the water surface, blowing the water away to Manchester and Wigan. If you extend the pound right through to Middlewich, that effect will be increased, and that was indeed found to be the case. Also 6 inches drop on the T&M is much more significant than 6 inches on the deeper Bridgewater. Because the difference in levels at the lock was usually very small, a single top gate was fitted with a very long beam and extremely large paddle. This enabled the lock to be used as, in effect, a Flash lock.

The end of the Kellogs traffic more or less coincided with the very bad breach at Bollington (1971?), after which MSC became cautious about their water levels and maintained the Bridgewater on average several inches lower than the T&M. The lock then became difficult/unsafe to use with the single gate, so new bottom gates were made (by MSC Co!) and fitted.

Those who advocate removing the lock should think back to a much more recent time, when a failed paddle in Manchester led to the Bridgewater dropping by a couple of feet. The stop lock protected the T&M entirely, without it every boat between Dutton and Middlewich would have been on the bottom.

 

Tim

 

Interesting stuff, but I somehow dont think the wind could manage to lower levels by as much as six inches on the canals? A westerly gale perhaps? On the sea it is different because there is a much larger catchment area of water plus the tides and wind working together can achieve some considerable effect - such as those conditions which led to the disastrous floods of 1953.

[Timleech]

Interesting stuff, but I somehow dont think the wind could manage to lower levels by as much as six inches on the canals? A westerly gale perhaps? On the sea it is different because there is a much larger catchment area of water plus the tides and wind working together can achieve some considerable effect - such as those conditions which led to the disastrous floods of 1953.

 

 

I've lived on or by the canal at Dutton/Preston Brook for 40 years, off and on, & I can assure you that I haven't made it up

 

The width of waterway is more or less irrelevant, it's the length along which the wind is blowing which matters. It's not an instant effect, it is most marked after a couple of days of sustained wind.

 

Tim

[mayalld]

I've just come across this old thread, & would like to make a couple of points about Dutton stop lock.

 

First, the levels were more equal some years ago, as for some years the Bridgewater was maintained at a higher level to facilitate the Kellogs grain traffic through Trafford Park. At that time, I'm told that British Waterways did decide to remove the gates altogether (circa 1960, I believe). They quickly found that it was a bad mistake, as there was too much variation in levels at Middlewich.

With the lock in place, the Bridgewater level at Dutton/Preston Brook can drop by 5 or 6 inches if there's a strong W or SW wind for a couple of days. This is caused by the action of the wind on the water surface, blowing the water away to Manchester and Wigan. If you extend the pound right through to Middlewich, that effect will be increased, and that was indeed found to be the case. Also 6 inches drop on the T&M is much more significant than 6 inches on the deeper Bridgewater. Because the difference in levels at the lock was usually very small, a single top gate was fitted with a very long beam and extremely large paddle. This enabled the lock to be used as, in effect, a Flash lock.

The end of the Kellogs traffic more or less coincided with the very bad breach at Bollington (1971?), after which MSC became cautious about their water levels and maintained the Bridgewater on average several inches lower than the T&M. The lock then became difficult/unsafe to use with the single gate, so new bottom gates were made (by MSC Co!) and fitted.

Those who advocate removing the lock should think back to a much more recent time, when a failed paddle in Manchester led to the Bridgewater dropping by a couple of feet. The stop lock protected the T&M entirely, without it every boat between Dutton and Middlewich would have been on the bottom.

 

Tim

Of course, when there is a lot of traffic coming through Preston Brook Tunnel, it is usually possible for a couple of hefty blokes to open Dutton Stop lock at both ends simultaneously, and get all the boats through at the same time.

 

IIRC, BW do occasionaly do it deliberately when there is a lot of traffic expected.

 

By and large though, stop locks only remain in use where equalising the levels would be difficult.

 

Hall Green is a case in point.

 

The lower pound of the Macc would be impassible if the level was lowered.

Harecastle Tunnel would be difficult if the upper pound of the T&M was raised.

 

Indeed, as Harecastle continues to sink, one option will be to lower the weir level on the T&M summit, and increase the fall at Hall Green

[Timleech]

Of course, when there is a lot of traffic coming through Preston Brook Tunnel, it is usually possible for a couple of hefty blokes to open Dutton Stop lock at both ends simultaneously, and get all the boats through at the same time.

 

IIRC, BW do occasionaly do it deliberately when there is a lot of traffic expected.

 

They did it once or twice when the lock was manned for boats attending the IWA national, at that time levels were fairly equal.

Generally, they strongly discourage the practice and have in the past written to the local Cruising Clubs to ask them to desist from doing it. If it's done when there's a substantial difference, there's risk of injury through gates flying shut, damage to gates or the structure, the wave sent along the canal can cause disruption to boats in the tunnel and to moored boats, etc etc.

 

Tim

[Adam]

Hi,

After bank dole lock on the selby canal it takes you on to the river aire and about half way between there and west haddersly the lock off the river there is beal lock and it says in my waterways guide it is 8ft but its about 1ft, and the weir looks about 5ft so how does that work?? i even went through the lock when the river was on flood but there wast much change

 

Regards Adam

[Keeping Up]

I'm sure that the OCC would have preferred a level junction, but the CCC was there first. Indeed for years they would not agree to a junction at Hawkesbury, so the canals were built side by side for another mile and a bit to Longford turn. So the bizarre sight of two unconnected canals with a towpath between them running in opposite directions existed so the CCC could collect more in the way of tolls.

 

My understanding also is that the stop lock at Marston joining the Ashby and Coventry canals was simply that with no change in level. But I could be wrong.

 

Tony

Fred Doerflinger's wonderful book (was it "Slow Boat through England" ?) recounting his hire-boat voyage from Aylesbury in the 60's he recounts that the stop lock at Hawkesbury was at that time always left open at both ends. Was he correct or was he confusing it with the one at Marston? It would have made the north end of the North Oxford very shallow.

 

Allan

[Liam]

Because of the position of this lock, it always causes jams on busy weekends, like at Easter when loads of boats are out and about. I've been stuck behind a few boats, in the tunnel, waiting for the jam to clear, and it's not notice. It has been known for the gates at both ends of the lock to be opened at once, thus allowing all the boats to get clear of the tunnel and through the lock, so that people are able to get through the lock and moor up before the tunnel in time, so they don't waste time hanging about.

 

I don't think the lock could be left over permanently though. Although the Bridgewater could take a couple of inches from the Trent & Mersey and hold it without any problems, I don't think the T&M could take it very well. It's not the shallowest on the system but even with 2ft 6 draught you can't go too near the side without scraping.

 

A couple of years ago, when the Bridgewater breached in Castlefield, it affected many miles of the canal (40 miles in total) because it has no locks. Also, due to the mis-management of the Bridgewater canal, the stop planks weren't put in place in time and the first one was put in about 10 miles from the breach itself! This, would, in effect, drain the T&M too, if it wasn't for the stop lock.

 

The ideal solution, for me, would be to leave the stop lock as it is at Preston Brook, but on busy weekends, just swing both gates open to get the boats through, making you close them after you.

[Timleech]

The ideal solution, for me, would be to leave the stop lock as it is at Preston Brook, but on busy weekends, just swing both gates open to get the boats through, making you close them after you.

 

If only life were that simple !

 

Several snags with that idea:-

 

one, the people opening the gates may have the best of intentions of getting them closed afterwards; I can tell you from observation that it doesn't work (usually). Somebody somewhere down the line will lose interest/lose the plot/not give a stuff, and the gates will get left open.

 

two, it isn't always safe to do it - sometimes the difference in levels is too great, but you can bet your life some idiots will still try. Who decides when it's safe, and takes the rap if it isn't & there's harm done?

 

three, there's a right of way across the lock. For me & my customers. It's the only access to my business premises, customers moorings etc. In years gone by, I've often been slaving away on Easter & may bank holiday weekends to get boats ready. It used to be Hotel boats for the start of the season. If I (and others) are doing our best to get the job done it can be intensely aggravating when there's a line of boats (illegaly) going through the lock & every one of the boaters thinks it more important for them to get through than for you to get your work done. Some of the Cruising clubs seem to have rules which require them to keep in a continuous line behind the admiral or commodore or whatever he is, and can get really agitated if the line is broken.

Even worse if we're stuck the wrong side of the lock with the gates left open (abandoned). That can be a ridiculous time waster

In recent years I've tried to avoid working on Bank Holiday weekends simply because it's bad for my blood pressure, but it's not always possible.

 

I have suggested in the past to BW that they man the lock on Bank Holiday weekends, their men could decide when it's safe to force the gates, and make sure that access is maintained. I honestly think that would be the best answer but they don't want to know because it would involve paying overtime.

 

If boaters stick strictly to the times, and keep a safe distance behind the boat in front, there should be no more than about 10 boats passing each way per hour and not much of a problem with queues. Unfortunately they don't.

 

Rant over

 

Tim

[Liam]

If boaters stick strictly to the times, and keep a safe distance behind the boat in front, there should be no more than about 10 boats passing each way per hour and not much of a problem with queues. Unfortunately they don't.

 

I always stick to the times, and I know you say it shouldn't happen, but it does. It has happened to me before and I know it's happened to other people aswell. It's at times like this when I've known the gates at both ends to be opened to clear it.

 

Not because people want to leave the gates open of course, but why don't you look into other ways of access to the dry dock?

[Timleech]

Not because people want to leave the gates open of course, but why don't you look into other ways of access to the dry dock?

 

 

Why should I (and do you really think I haven't thought about it ? )?

There is access provided by BW as part of my agreement, if the lock is operated properly there's no problem.

Of course I would love to have road access, but it would be prohibitively expensive bearing in mind the other limitations of the site. Also it would be the more than a mile by 'road' from my workshop, which is on the other side of the lock, 100 metres on foot.

The only other way would be a swing bridge or high level bridge, the swing bridge wouldn't be any better than the lock gates in the Bank Holiday situation.

It's only really a problem at Bank Holidays when the Cruising Clubs are out en masse. BW's answer when I raised the matter some years ago and suggested manning the lock was that the CCs should work within the rules (and BW wrote to tell them so), there was no reason why BW should incur extra costs to accomodate them just because they wanted to go on mass cruises.

 

Tim

[Liam]

As I said, I didn't ask about alternative access so people can leave the lock open, it was just a general question as it can't be the most easiest way of getting working gear to the dry dock.. I'm thinking along the lines of engine replacements and heavy machinery.

 

Anyway, getting back on topic... you say you've had problems with cruising clubs? I'm a member of one of the cruising clubs on the Bridgewater. Maybe you could let me know which ones are causing a problem via PM, so I can have a quiet word with the people associated to them, if you want to, of course.

[Timleech]

As I said, I didn't ask about alternative access so people can leave the lock open, it was just a general question as it can't be the most easiest way of getting working gear to the dry dock.. I'm thinking along the lines of engine replacements and heavy machinery.

 

It isn't, but I've lived with it for more than 20 years. Heavy stuff has to come in by boat or, very occasionally, across the farmer's fields.

 

Anyway, getting back on topic... you say you've had problems with cruising clubs? I'm a member of one of the cruising clubs on the Bridgewater. Maybe you could let me know which ones are causing a problem via PM, so I can have a quiet word with the people associated to them, if you want to, of course.

 

Thanks for the offer, it's not really 'problems with cruising clubs' so much as problems created by the sheer numbers of boats when the CCs come through, on top of already heavy bank holiday traffic. 40 or 50 boats trying to come through tunnel & lock as close together as they can is bound to stretch things a bit. It's not as bad as it was with the old tunnel times, when it wasn't unknown for the whole lot to come through on one 'tunnel', things did tend to get seriously manic then!

 

Tim