Gates. Open or closed?

[twbm]

I think z is unnesessary and so does my pet sebra,

 

hoo I liberated from a soo.

 

I think is amaesing how many unnesessary letters there are in the alphabet. We kood get rid of c as well.

 

Prizoomablee yoo meen Alfabet?

 

I find "z" isn't used anywhere near enough in British spelling - I like to keep it alive & well excerized

 

As long as you're not offended when we just regard it as bad spelling.

[Scholar Gypsy]

Ok, I know this question just highlights my lack of basic knowledge &/or understanding but I've got to ask.

 

Why is it ok to leave gates open on canalized (is this a word?) Rivers.

 

I understand about closing gates on canals owing to not draining pounds and water conservation, but why is it different on rivers?

 

Just to be really pedantic, there are some sections of river (the Soar is a good example in Loughborough) where the river proper wanders off for a bit over a weir, and the canalised section is separated for a longer distance, and falls through a couple of locks (and indeed I think part of that section is called the Loughborough canal) before joining up again with the river. All the river flow goes down the river bit not the canal bit.

 

So for water conversation & gate closing purposes, those bits of the navigation are really canals not rivers.... Hope that helps!

[Nightwatch]

K&A is a bit like that at times.

[John Williamson 1955]

Reading another thread, it appears that someone has got their nickers in a twist because of gates being left open.

But why are we expected to close the gate/s after leaving a lock?

 

Rob....

Given the normal state of gate maintenance on the canals, closing all gates and paddles reduces water use, as it reduces leakage by roughly 50%. On some canals, notably bits of the Grand Union, the lock walls leak and water floods the cellars of the lock cottages, so you are asked to leave the bottom gates open at those locations.

 

My normal guideline is that if I see another boat approaching I leave 'em open, otherwise, I close them. In either case, I drop all the paddles.

[Paul C]

Another point which is pertinant but I don't think its been mentioned before:

 

If you leave the gates open:

 

the chance of them being open for the next boater + the chance of someone behind you being inconvenienced by them being open = 100%

 

If you close them:

 

the chance of the lock being at exactly the same level as when you left it < 100%

 

due to leakage. So, any boater after you (whatever the direction of their travel) may need to use the paddles to achieve the level, then open the gates.

[David Mack]

 

I find "z" isn't used anywhere near enough in British spelling - I like to keep it alive & well excerized

 

A couple of years ago I had an extended dialogue with Canadian colleagues about this. There's lots of words where the English use an 's' and the Americans a 'z'. which is sort of OK, and Microsoft's spellchecker will generally sort it if you select the right language for the spell check. But its really confusing that for some of these words the Canadians use the 's', but for others they use the 'z'. How's a poor Englishman supposed to know which to use?

[bassplayer]

Another point which is pertinant but I don't think its been mentioned before:

 

If you leave the gates open:

 

the chance of them being open for the next boater + the chance of someone behind you being inconvenienced by them being open = 100%

 

If you close them:

 

the chance of the lock being at exactly the same level as when you left it < 100%

 

due to leakage. So, any boater after you (whatever the direction of their travel) may need to use the paddles to achieve the level, then open the gates.

I think it is mainly about leakage and unnecessary loss of water. It's probably a good back up to shut both sets of gates in the very unlikely event a gate breaches.

 

The only time I'd intentionally leave a gate open is if I knew a boat is coming the other way. If I'm in a very good mood I'll open up the paddles after I've closed up to help the boat(s) behind (only if there's one there).

Edited June 26, 2015 by bassplayer

[Dave Payne]

Always wondered why locks have one gate at one end and two at the other??

 

Pain up the arse walking round to close the other gate!

[Paul C]

Always wondered why locks have one gate at one end and two at the other??

 

Pain up the arse walking round to close the other gate!

 

Simple answer: they don't!

 

More detailed answer: its due to the weight of the gate, obviously a bottom gate needs to be taller than a top gate, so to avoid a bottom single gate being too heavy a "compromise" of making it a pair of gates is often used. Of course, this only relates to narrow locks, broad locks tend to always have pairs at each end and the fact that the bottom pair are heavy is just a fact of life because there's no pragmatic/cheap/cost effective alternative.

[Dave Payne]

Cheers, makes sense i guess.

[adam1uk]

 

Simple answer: they don't!

 

More detailed answer: its due to the weight of the gate, obviously a bottom gate needs to be taller than a top gate, so to avoid a bottom single gate being too heavy a "compromise" of making it a pair of gates is often used. Of course, this only relates to narrow locks, broad locks tend to always have pairs at each end and the fact that the bottom pair are heavy is just a fact of life because there's no pragmatic/cheap/cost effective alternative.

 

The Oxford has single bottom gates south of Banbury and two gates north of Banbury. I seem to remember reading that the double gates were a money saving measure. Locks with two gates can be a little bit shorter, as they need less room to swing open. I've never fully understood this, as you'd think the cost would be offset by needing to build two gates, have two balance beams, two cups, two collars etc.

[Arthur Marshall]

 

Simple answer: they don't!

 

More detailed answer: its due to the weight of the gate, obviously a bottom gate needs to be taller than a top gate, so to avoid a bottom single gate being too heavy a "compromise" of making it a pair of gates is often used. Of course, this only relates to narrow locks, broad locks tend to always have pairs at each end and the fact that the bottom pair are heavy is just a fact of life because there's no pragmatic/cheap/cost effective alternative.

Bosley's locks are as far as I know the only narrow ones with a pair of gates at each end. Now they really are a pain...

[Paul C]

Bosley's locks are as far as I know the only narrow ones with a pair of gates at each end. Now they really are a pain...

 

the last 2 on the Shroppie are too - at the Ellesmere Port end. These pair of locks also has the ineresting feature of a short intermediate pound combined with no weir/overflow and a sensitive area which can be flooded next to the lock.

[ditchcrawler]

Another point which is pertinant but I don't think its been mentioned before:

 

If you leave the gates open:

 

the chance of them being open for the next boater + the chance of someone behind you being inconvenienced by them being open = 100%

 

If you close them:

 

the chance of the lock being at exactly the same level as when you left it < 100%

 

due to leakage. So, any boater after you (whatever the direction of their travel) may need to use the paddles to achieve the level, then open the gates.

Correct

 

 

My normal guideline is that if I see another boat approaching I leave 'em open, otherwise, I close them. In either case, I drop all the paddles.

And if you do that on a lock where you are requested to leave it empty, how long do you think it would remain empty for if there was no other traffic.

[John Williamson 1955]

Correct

And if you do that on a lock where you are requested to leave it empty, how long do you think it would remain empty for if there was no other traffic.

As the request from CRT at the locks I have in mind is to leave them empty with the bottom gates open, until they are next used. The request overrides my normal habit.

[magpie patrick]

Always wondered why locks have one gate at one end and two at the other??

 

Pain up the arse walking round to close the other gate!

 

Quick answer

 

Single gates were an innovation for narrow locks - prior to this nearly all locks had double gates at both ends

 

even by 18th century standards narrow lock gates were small - they really don't need to be double to make them work. A number of narrow locks have single gates at both ends - the Canal Du Berry in France, which is almost narrow, has single gates at both ends.

 

BUT, the bottom gates open into the lock, and thus add to the length of chamber to be filled and emptied - for water conservation reasons therefore double bottom gates have an advantage. This advantage doesn't apply at the top as the gate opens outwards.

 

Single gates were also presumably cheaper as the Southern Stratford and the Oxford South of Banbury have them, lengths of canal built after their respective companies had run out of money.

 

the last 2 on the Shroppie are too - at the Ellesmere Port end. These pair of locks also has the ineresting feature of a short intermediate pound combined with no weir/overflow and a sensitive area which can be flooded next to the lock.

 

And there were a lot more at one time - The narrow locks on the Shroppie, the Ashton Canal, probably others as well

[David Mack]

Single gates were also presumably cheaper as the Southern Stratford and the Oxford South of Banbury have them, lengths of canal built after their respective companies had run out of money.

 

And the BCN who kept changing their mind about which they preferred.

[magpie patrick]

And the BCN who kept changing their mind about which they preferred.

 

Indeed - the original Birmingham Canal had double whilst the original Birmingham and Fazeley had single bottom gates. I don't know why the differed although Farmers Bridge Locks were built through an area that was already built up and space may have been at a premium.

 

The BCN then went for single gates for a while - I'd always assumed because they were quicker to operate, but when it came to Rushall, Perry Barr and Bently they changed their minds again, I think these were the last to be built?

 

Oddly, one lock in the Walsall Flight is different to the rest.

[adam1uk]

Bosley's locks are as far as I know the only narrow ones with a pair of gates at each end. Now they really are a pain...

The pain with those is not so much that they're double, but that they don't have footways so you can't step across the gap when one is closed and the other empty. The bottom gates on the Aylesbury Arm are similar in that respect.

[ditchcrawler]

As the request from CRT at the locks I have in mind is to leave them empty with the bottom gates open, until they are next used. The request overrides my normal habit.

Thats fine but I have often watched boaters at Winkwell empty the lock and then close the gates and paddles so the lock just fills up again when they have gone.

[Alan Saunders]

If an animal; cow, sheep, dog, even waterfowl or person falls into the lock they will find it difficult to climb out. Leave the gate(s) open and they can swim out of the lock and climb the bank. Safety first!

 

Alan

[nicknorman]

If an animal; cow, sheep, dog, even waterfowl or person falls into the lock they will find it difficult to climb out. Leave the gate(s) open and they can swim out of the lock and climb the bank. Safety first!

 

Alan

For humans, that is what the lock ladder is for. Much easier than trying to clamber up a lock landing!

[bassplayer]

If an animal; cow, sheep, dog, even waterfowl or person falls into the lock they will find it difficult to climb out. Leave the gate(s) open and they can swim out of the lock and climb the bank. Safety first!

 

Alan

I've never had a sheep on my boat in a lock......oh....hang on...

[John Williamson 1955]

Thats fine but I have often watched boaters at Winkwell empty the lock and then close the gates and paddles so the lock just fills up again when they have gone.

Which means that the top gates leak badly enough that it's worth leaving both sets of gates and paddles closed to save water.

[GUMPY]

Which means that the top gates leak badly enough that it's worth leaving both sets of gates and paddles closed to save water.

Not so!

On the GU and K&A most of the bywashes are through the top paddle culvert so if the canal is on weir the lock will always fill up and then weir over the bottom gates.