Stop locks

[magpie patrick]

This probably demonstrates the need for a forum area that suits sad people who have nothing better to think about, but here goes.

 

The discussion about stop locks led me to draw up the following list

 

Operational stop locks

• Hall Green (one foot)

• Hawkesbury (approx. 6 inches)

• Autherley (approx. 6 inches)

• Preston Brook (approx. 2 inches)

 

Open stop locks (used to have a fall but no longer have)

• Neachals (Spaghetti Junction)

• Kings Norton

• Dundas (Somerset Coal Canal)

 

Two of these were also built to a wide beam but later narrowed

 

Locks that have a change of level and regulate the flow from a river to a canal

• Rotherham

• Droitwich Barge

• Firepool

 

Locks at canal junctions that didn’t obviously have a change level but must have had a function as they had gate recesses and were at the junction of two companies

• Marple (Macclesfield Canal)

• Second chamber at Hall Green (Macc/T&M)

• Gas Street

• Horsely Fields

• Pontymoile

• Paddington

• Warwick Bar

• Langley Mill

 

Stop locks that have been removed from a navigable route

• Braunston

• Bromley by Bow

 

Stop locks on canals that have now closed

• Barnsley

• Stourbridge Extension

• Abercynon (junction of the Glamorgan and Aberdare Canals)

 

Canal company junctions that didn’t have a stop lock at all

• L&L/Bridgwater

• Coventry/Birmingham and Fazeley

• Coventry/Trent and Mersey

 

I’m not sure I dare list any more

[Tuscan]

Fenny Stratford?

[alan_fincher]

Stop locks that have been removed from a navigable route

• Braunston

• Bromley by Bow

. Little Tring, Wendover Arm, GU

 

Fenny Stratford?

No, never a stop lock.

[Liam]

I'm probably wrong but I thought that there was more than a 2 inch level difference at Dutton Stop Lock, Preston Brook?

 

Tim?

[Timleech]

I'm probably wrong but I thought that there was more than a 2 inch level difference at Dutton Stop Lock, Preston Brook?

 

Tim?

 

It's not Preston Brook

 

The level at Dutton varies, as per another thread, usually these days in the region of 3 or 4 inches but can be more.

 

Tim.

[MtB]

This probably demonstrates the need for a forum area that suits sad people who have nothing better to think about, but here goes.

 

The discussion about stop locks led me to draw up the following list

 

Operational stop locks

• Hall Green (one foot)

• Hawkesbury (approx. 6 inches)

• Autherley (approx. 6 inches)

• Preston Brook (approx. 2 inches)

 

<snip>

 

 

I'm struggling to understand the difference between a stop lock and an an ordinary lock. Is it just that the level difference is small? Autherley lock for example looks to me like a perfectly normal lock,if a bit shallow. Does this make the treacherous 12" County Lock in Reading on the K&A a stop lock?

 

Or is a stop lock where one company's waters meet another's, regardless of any level difference?

 

Mike

[churchward]

An aditional open/de gated stop lock would be at Marston Junction between the Coventry and Ashby Canals.

 

The Trent & Mersey and Coventry canal junction at Fradley is an interesting one. I guess the Coventry canal company didn't need to build a stop lock as they would be the beneficiary of the higher locks on the T&M flight there. However the T&M were clever in that they built a bypass feed gully that takes water from above lock 3 past the junction and comes out below lock 4. Thus saving a lot of water that would otherwise feed the Coventry pound.

 

OK OK I'll get my anorac!

Edited August 6, 2012 by churchward

[alan_fincher]

I'm struggling to understand the difference between a stop lock and an an ordinary lock. Is it just that the level difference is small? Autherley lock for example looks to me like a perfectly normal lock,if a bit shallow. Does this make the treacherous 12" County Lock in Reading on the K&A a stop lock?

 

Or is a stop lock where one company's waters meet another's, regardless of any level difference?

 

Mike

Not sure what the "official" definition is, (if there is one!).

 

But to me, if they were put there for reasons of water control, rather than because the geography, and the canl's route through it, actually dictated a level change, then they are a stop lock.

 

That said, I'm not sure how you categorise those locks that sometimes are brought into play, but at others are left open, such as some on the Soar.

[churchward]

 

That said, I'm not sure how you categorise those locks that sometimes are brought into play, but at others are left open, such as some on the Soar.

They are flood locks surely.

 

I agree on the definition of stop locks it is not the depth of the levell difference it is a lock that protects one canal companies water from feeding into anothers.

Edited August 6, 2012 by churchward

[Argey_bargey]

as I often pass through Preston brook & dutton stop lock I often think is there any point to that lock actually being there?

[David Schweizer]

It has always been my understanding that stop locks were put in place where one company's canal joined another, in order that the flow of water from one to the other could be controlled and, if necessary, payed for.

 

There were cases where agreement between two companioes could not be reached, and goods had to be transferred from one boat to another, I believe Gas Street was one of those, until the stop lock was introduced.

[alan_fincher]

It has always been my understanding that stop locks were put in place where one company's canal joined another, in order that the flow of water from one to the other could be controlled and, if necessary, payed for.

 

There were cases where agreement between two companioes could not be reached, and goods had to be transferred from one boat to another, I believe Gas Street was one of those, until the stop lock was introduced.

Being pedantic, (of course!), but some times two companies were not involved, and it was simply one company trying to protect its own water supplies.

 

As an example, the stop lock introduced at Little Tring, about a mile and a half down the Wendover Arm, had nothing to do with multiple companies, but allowed a leaky stretch ofa branch to be isolated from te main summit level of the GU.

Edited August 7, 2012 by alan_fincher

[Leo No2]

How would you classify Worsfold Gates and Walsham Gates (turf sided still) - Wey Navigation - Locks in their own right at times of flood (although I have never seen Walsham used as such) but just 'open gates' at 'normal' times. Walsham had about a 3 inch difference last time I was there in flood conditions.

Edited August 7, 2012 by Leo No2

[Ray T]

This probably demonstrates the need for a forum area that suits sad people who have nothing better to think about, but here goes.

 

The discussion about stop locks led me to draw up the following list

 

<snip>

 

I'm not sure I dare list any more

 

 

 

Why not, I find it of fascinating historical interest.

 

One I know of which has been removed is at the entrance to The Ashby Canal.

[Timleech]

as I often pass through Preston brook & dutton stop lock I often think is there any point to that lock actually being there?

 

Yes.

See the thread about Gas Street stop lock.

Also it still does its job, the canals either side are still in different ownership.

If it hadn't been there when the Bridgewater had their major water loss problem a few years ago, the T&M to Middlewich would have been unuseable for weeks.

It gives people something to do, why do they complain about it when there's nothing else to do all the way from Middlewich to Wigan?

 

Tim

[billS]

What about the single gate which is still extant, and still looks operational at Shipton on Cherwell. What is its purpose - flood protection? Is it ever used?

[IanM]

Stop locks on canals that have now closed

• Barnsley

• Stourbridge Extension

• Abercynon (junction of the Glamorgan and Aberdare Canals)

 

 

 

Latton Basin Stop Lock at the junction between the Thames & Severn and the North Wilts.

[Pluto]

Yes.

See the thread about Gas Street stop lock.

 

Tim

I've just put something there about the L&LC/Bridgewater junction at Leigh. There were also stop gates at the top of Wigan flight and the top of Johnsons Hillock to protect the water supply between the Lancaster and L&LC. The gate recesses are still there.

[DaveC]

What about the single gate which is still extant, and still looks operational at Shipton on Cherwell. What is its purpose - flood protection? Is it ever used?

 

That is a STOP GATE. Used if there is a breach or serious leak. In some places there are stop gates facing opposite directions (or at least there used to be) if the canal is carried on say, a long embankment and the leak could be in either direction. There is also a device known as a fall gate, which would be automatically deployed in the event of a serious breach. This normally lies flat on the bottom of the canal.

 

Many examples of stop gates (or the site of them) on the Kennet and Avon canal.

 

Dave

[the grinch]

I'm struggling to understand the difference between a stop lock and an an ordinary lock. Is it just that the level difference is small? Autherley lock for example looks to me like a perfectly normal lock,if a bit shallow. Does this make the treacherous 12" County Lock in Reading on the K&A a stop lock?

 

Or is a stop lock where one company's waters meet another's, regardless of any level difference?

 

Mike

 

the latter used to stop water being passed to another companies waterway without charge/control

 

another strange one is Norton Junction where there is a guaging lock although as far as i know it never had gates!

 

Being pedantic, (of course!), but some times two companies were not involved, and it was simply one company trying to protect its own water supplies.

 

As an example, the stop lock introduced at Little Tring, about a mile and a half down the Wendover Arm, had nothing to do with multiple companies, but allowed a leaky stretch ofa branch to be isolated from te main summit level of the GU.

 

wasn't it built to allow the wendover arm level to be lowered slightly as it wouldn't hold water properly?

[MoominPapa]

Can we have a new category for Lode's End Lock on the Middle Level? It's sometimes possible to pass through on the level, but sometimes there is a few inches difference and it has to be used as a pound lock. Sometimes there's a flow "uphill" through the open gates, and they have a chain which keeps them close enough to close should the flow reverse. Interestingly, the top gates are several feet higher than the bottom gates, so for some possible levels to the East of the lock it wouldn't be possible to use it as a pound lock since the water would flow away over the bottom gates long before a level was reached. The flood conditions to cause that would probably preclude navigation anyway.

 

MP.

[churchward]

Why not, I find it of fascinating historical interest.

 

One I know of which has been removed is at the entrance to The Ashby Canal.

Yup see post #7

[the grinch]

This normally lies flat on the bottom of the canal.

 

 

Dave

 

interestingly enough i had a lengthy discussion with BW at Bradley workshops about these recently and David was saying that those fitted in the 80's at places around the BCN have issues and weren't very sucessful as mud just gets in and over the recesses making it very difficult to use them.

[Hairy-Neil]

An aditional open/de gated stop lock would be at Marston Junction between the Coventry and Ashby Canals.

 

The Trent & Mersey and Coventry canal junction at Fradley is an interesting one. I guess the Coventry canal company didn't need to build a stop lock as they would be the beneficiary of the higher locks on the T&M flight there. However the T&M were clever in that they built a bypass feed gully that takes water from above lock 3 past the junction and comes out below lock 4. Thus saving a lot of water that would otherwise feed the Coventry pound.

 

OK OK I'll get my anorac!

 

Am I wrong in assuming that lock 3 would at one time have emptied into the reservoir and lock 4 have filled from it. Basically like a huge side pond.....

[DaveC]

interestingly enough i had a lengthy discussion with BW at Bradley workshops about these recently and David was saying that those fitted in the 80's at places around the BCN have issues and weren't very sucessful as mud just gets in and over the recesses making it very difficult to use them.

 

The one I am thinking of is on (in?) the long pound of the K & A. In the 1960s / 1970s when I worked for BWB the BWB divers raised it and found it as good as the day it was fitted (1810 or thereabouts), the only part to have suffered was the wooden "jamb" that it shut against when in the raised position. When it was raised the gaps were filled with clay filled sandbags but it didn't need anything at the bottow, that was a good fit. I think that particular fall gate was in the bridge hole by the now visitor moorings at All Cannings but I'm not 100% sure - 'twas a long time ago. If you look at the recess in the brickwork, where there is or was a fall gate there is no metal work for stop gates to swing in - as there is at Pewsey Wharf bridge for instance, and no stop plank grooves. Often there is the remains of the wooden "jamb" still visible.

 

Dave