Lock gates left open

[alan_fincher]

I was told today that the cost of back pumping on the K&A is £400,000 a year. Sounds like a good reason to shut gates.

 

Sounds like a good reason to fix them, too

I don't specifically know about K&A, but surely the principle reason for back pumping is to return water uphill that has been used by boats working through locks.

 

In many places, even if all gates were left shut and/or locks leaked not one jot, back pumping would still be required if traffic volumes demanded it.

[Neil TNC]

 

That's interesting, I was unaware of that. Do you know any specific locks that have this?

 

There are some locks on the Perry Bar Flight, which still have a culvert opening behind the bottom gates, we have shut the bottom gates this way.

[Hairy-Neil]

I do0n't believe any of them still do. I was told they were deliberately blocked up, so that people wouldn't be tempted to use them to shut the gates.

 

 

I'm with Richard on thisone, in that one of the Garrisson locks is still working as built. IIRC, the Tame Valley locks (Perry Barr) were originally also built to this design, but have now been 'standardised'.

[ymu]

I chug alone, sometimes, and tend to leave the exit gate/s open unless I can see a boat following me. Seems better to leave the lock set up with gate open than to shut it and it leaks so it's in no ones favour.

I don't get the argument about shutting the gates to save water, don't see what difference that would make?

Casp'

If the lock gradually empties/fills from a leaky bottom/top gate, then boaters going up/down use less water emptying/filling it, whilst boaters going down/up use no more water than if the top/bottom gate had been left open. Plus the leak will reduce over time as the lock empties/fills, so less water would leak overall.

 

BW are only replacing lock gates at about half the rate required, so there's a lot of leaking going on. Unless both gates leak at an equal rate, closing both minimises the amount of water lost.

 

 

On this topic, does anyone know what work they were carrying out at Roundham lock (Kidlington, on the South Oxford) a couple of winters ago? It closed for a few days with some structural-looking work being done, but it leaked worse than ever when we went through a few months later.

[alan_fincher]

Unless both gates leak at an equal rate, closing both minimises the amount of water lost.

Being completely pedantic, you really only save water by shutting both gates if either......

 

1) You are leaving a full lock, and bottom gates leak more than top.

 

or

 

2) You are leaving an empty lock, and top gates leak more than bottom.

 

In the cases where.....

 

3) You are leaving a full lock, and top gates leak more than bottom.

 

or

 

4) You are leaving an empty lock, and bottom gates leak more than top.

 

then there is really nothing gained by shutting exit gates.

 

The problem of course is, that unless you are completely familiar with a particular lock, it is often not possible to judge whether you have a case where shutting up will help or not, which is why I guess they try and have a blanket "rule" to always do so.

 

On the topic of the Buckby flight, it is just possible that those involved know that some of the gates habitually drift or blow open anyway, and hence see little point in trying to close up.

 

There are certain locks elsewhere on the GU that we know never stay shut, so why waste time trying to do so, if you know you'll not be 100 yards away before at least one gate has re-opened ?

[ymu]

Being completely pedantic, you really only save water by shutting both gates if either......

Thinking about it, the entire "unless they leak at the same rate" point is moot, because the rate at which the gates leak will depend on how full the lock is. As the lock fills up, the top gate will leak less and the bottom gate more, and vice versa if it's emptying. Some locks might have an equilibrium point, which could be when the lock is either full or empty but is more likely to be somewhere in between, and it can't be both.

 

Presumably the different rules followed on rivers and canals are precisely because water is rarely an issue on a navigable river but is often a challenge on canals.

[Woollymishka]

As we all know (hopefully?) there are exceptions to gates not being closed on exiting and also to leave them full (the K & A is one example). However the behaviour of some boaters beggars belief and dropping paddles and leaving gates open (when they should be shut is just ******* laziness). We use the Buckby flight on a regular basis with groups of young people and trying to show them good practice when some idiot decides they know better does make life interesting and at times challenging. If I was sharing a lock with someone who did this sort of thing - I usually say that I will wait for someone who knows what they are doing. Keith - sorry that you met someone that was abusive - not pleasant - what a peasant!

[alan_fincher]

Presumably the different rules followed on rivers and canals are precisely because water is rarely an issue on a navigable river but is often a challenge on canals.

The whole topic has been much debated on here in the past, and generally I feel it's easier to (try to!) close up if you can as a matter of course, if nobody is obviously approaching. May not be the best rule in the world, but it is the one BW claim to want you to follow on most canals, so trying to swim against the tide seems to just cause confusion to me.....

 

However BW hardly help the case, as some examples.....

 

1) Many locks in our area still contain both the permanent signage to suggest you close everything to save water, but will then have a "temporary" sign to say the lock must be left empty and/or a bottom paddle drawn. Many of those "temporary" signs have remained unchanged for decades!

 

2) Locks on the Regents and lower parts of the GU below Bulls Bridge actually have signs saying that you must leave all top gate paddles and gates shut on leaving. The inference is that you do not need to do this with bottom gates, despite BW's more general guideline in Boater's Handbook and the like that you should.

 

3) On the Lea and Stort, (which are more like canals than rivers, frankly, and do actually sometimes have "low pounds"), we were quickly told by boaters that you don't shut exit gates. Conversations with two different sets of BW length men said the same - "don't shut exit gates". And yet most of the fully electric locks have signs saying all gates and paddles must be shut on exit, (despite the gates normally swinging open by around 6" when you take your finger off the button!...

Edited February 13, 2011 by alan_fincher

[Sir Nibble]

Shut both gates on a full lock, gates leak, we know they do and the bottom gate will always leak more on a full lock. Now in order to enter that lock from above you have to tie up, go ashore and lo! the leakage has to be replaced by cracking a paddle to equalise water levels before you can open the gate to go in, hence the water "saved" is now lost. This means one stop and tie up, at least one paddle movement and a gate to be opened and closed. If the gate had been left open you could motor in an save all that effort and get away with one gate movement. With an empty lock the top gate will always leak more and once again it's tie up, crack a paddle to equalise and open the gate and again any water "saved" is lost. If the lock is against you then you have one more gate movement to perform before setting it.

In short, the balance is that more work is caused to all users by shutting gates and no water whatever is saved as it is lost when the levels are equalised.

Thinking about this rather than slavish adherance to an ill thought out policy which has no force behind it other than a comparatively recent and futile ettiquette, shows that leaving gates open is niether thoughtless nor inconsiderate.

[alan_fincher]

However the behaviour of some boaters beggars belief and dropping paddles and leaving gates open (when they should be shut is just ******* laziness). We use the Buckby flight on a regular basis with groups of young people and trying to show them good practice when some idiot decides they know better does make life interesting and at times challenging.

The problem is that when as many ambiguities exist as I have started to allude to above, it is rather too easy to dismiss people as idiots, just because they don't know of some local situation or "rule", (either written or unwritten).

 

No doubt we pissed off a number of locals the first time we went up the Lee & Stort by closing up at every lock we left, but, (for example) Bw tell you to operate by the Boaters Handbook, and in the absence of any other guideline, that's really all you can do. A bit of a shame the Boaters Handbook says one thing but local BW staff often say the opposite.

[Chris Pink]

Shut both gates on a full lock, gates leak, we know they do and the bottom gate will always leak more on a full lock. Now in order to enter that lock from above you have to tie up, go ashore and lo! the leakage has to be replaced by cracking a paddle to equalise water levels before you can open the gate to go in, hence the water "saved" is now lost. This means one stop and tie up, at least one paddle movement and a gate to be opened and closed. If the gate had been left open you could motor in an save all that effort and get away with one gate movement. With an empty lock the top gate will always leak more and once again it's tie up, crack a paddle to equalise and open the gate and again any water "saved" is lost. If the lock is against you then you have one more gate movement to perform before setting it.

In short, the balance is that more work is caused to all users by shutting gates and no water whatever is saved as it is lost when the levels are equalised.

Thinking about this rather than slavish adherance to an ill thought out policy which has no force behind it other than a comparatively recent and futile ettiquette, shows that leaving gates open is niether thoughtless nor inconsiderate.

 

I'm with you here, there's nothing more frustrating than approaching a lock with gates shut and the level 20% full or empty so you not only have to open the gates (again) you have to open the paddles. If you open one paddle it takes for ever so that's a walk round the lock and even with both paddles open the last 20% takes 50% of the time of locking.

 

This phaff effectively doubles a locking time and in a flight can be so frustrating.

 

So leave 'em open peeps, easier for you, 50% chance of being easier for the next boat and as any fuul do no the water loss through leaky gates is the same in both cases.

[ymu]

Shut both gates on a full lock, gates leak, we know they do and the bottom gate will always leak more on a full lock. Now in order to enter that lock from above you have to tie up, go ashore and lo! the leakage has to be replaced by cracking a paddle to equalise water levels before you can open the gate to go in, hence the water "saved" is now lost. This means one stop and tie up, at least one paddle movement and a gate to be opened and closed. If the gate had been left open you could motor in an save all that effort and get away with one gate movement. With an empty lock the top gate will always leak more and once again it's tie up, crack a paddle to equalise and open the gate and again any water "saved" is lost. If the lock is against you then you have one more gate movement to perform before setting it.

In short, the balance is that more work is caused to all users by shutting gates and no water whatever is saved as it is lost when the levels are equalised.

Thinking about this rather than slavish adherance to an ill thought out policy which has no force behind it other than a comparatively recent and futile ettiquette, shows that leaving gates open is niether thoughtless nor inconsiderate.

You're right about the extra pfaffing, but not about the amount of water lost to leaks. If the top gate is left open on a full lock, the bottom gate will leak faster than if the lock was allowed to gradually empty. If the bottom gate is left open on an empty lock, the top gate will leak faster than if the lock was allowed to gradually fill.

 

Obviously, the solution is to maintain the locks better, but that's not something the average boater can do much about, beyond not abusing the infrastructure. In the absence of proper maintenance by BW, we need to do what we can to minimise spend on water supply.

[casper ghost]

On the Shroppie and the Llangollen they have a weir that allows water to flow past the locks therefore the worry about a lock leaking doesn't come into it..

I do, as a rule, close the top gate on exit as that's fairly easy, but when going down it's not that easy to shut the bottom gates on exit and I still don't see any point, uness I see a boat following me.

Casp'

[Chertsey]

I'm with you here, there's nothing more frustrating than approaching a lock with gates shut and the level 20% full or empty so you not only have to open the gates (again) you have to open the paddles. If you open one paddle it takes for ever so that's a walk round the lock and even with both paddles open the last 20% takes 50% of the time of locking.

 

This phaff effectively doubles a locking time and in a flight can be so frustrating.

 

So leave 'em open peeps, easier for you, 50% chance of being easier for the next boat and as any fuul do no the water loss through leaky gates is the same in both cases.

 

Good point Chris but again surely it only holds true 50% of the time. Say a lock leaks at the top. The bottom gates are shut and it is half full because of the water that has leaked in. If I am going up, then I have to empty it first, and no water is saved (and I am inconvenienced). But if I am going down, half a lockfull of water has been saved, and I only have to wait half as long for it to fill. The same in reverse with a full lock leaking at the bottom. I'm kind of playing devil's advocate here because in principle I am in favour of leaving gates open on leaving (but in practice I usually shut them like a good girl). As well as knowing where and how much a lock is leaking, it is also relevant to have some idea of the predominant direction of traffic (if there is one).

[jonk]

Surely if the lock is being used by a fair number of boats then the amount of water lost by leakage will be insignificant? If on the other hand the lock is not used by many boats then will the leakage be any more than one boat passing through should the lock be set against it - seems unlikely to me unless it is a really bad leak, and then it should be fixed anyway!

I don't know about you but I love approaching a lock that has the gate open - it looks so inviting, as though it's waiting with open arms for me! It's even better for Sandy - who does the hard work usually.

[Timleech]

Surely if the lock is being used by a fair number of boats then the amount of water lost by leakage will be insignificant? If on the other hand the lock is not used by many boats then will the leakage be any more than one boat passing through should the lock be set against it - seems unlikely to me unless it is a really bad leak, and then it should be fixed anyway!

I don't know about you but I love approaching a lock that has the gate open - it looks so inviting, as though it's waiting with open arms for me! It's even better for Sandy - who does the hard work usually.

 

Leaving gates open would be fine as a policy on a well-used, well-maintained waterway with lock keepers who patrol at the end of the day to check that everything is tight.

If the waterway isn't busy, or isn't well maintained, and isn't checked at the end of the day then leaving gates open will give rise to problems somewhere along the line. As has been said, bottom gates will generally leak more than top gates - especially on narrow locks with a single top gate but mitred bottom gates - so closing top gates is particularly important. Some of you might be amazed at how often boaters fail to close paddles properly, even when they think they have done it, and having both ends of the lock closed reduces the problem that can cause.

 

Tim

[Mac of Cygnet]

 

 

1) Many locks in our area still contain both the permanent signage to suggest you close everything to save water, but will then have a "temporary" sign to say the lock must be left empty and/or a bottom paddle drawn. Many of those "temporary" signs have remained unchanged for decades!

 

 

 

This is usually because the full lock leaks into a nearby building. There are at least three locks on the Huddersfield Narrow with permanent signs to this effect. The owner of the lock cottage at Dobcross is on watch monday, wed & fri making sure this is done!

 

Mac

[RichardN]

Don't forget to factor into your calculations that there is a pound above the lock. Lady Muck has posted several times what happens to her pound when people leave one set of gates open. Tim's post about paddles not being fully closed is also a very good point.

 

Maintaining gates better: I am with you on that one. Some more figures from yesterdays trip to Caen Hill: Changing a set of lock gates costs £50,000, annual spend on the K&A is £4 million, I asked how much would they like to spend not to get a pristine waterway but a 200 year waterway in reasonable nick. That was a figure of £6 million for at least 2 years, hard to tell thereafter but possibly dropping to £5 million. When I add in the £400,000 pumping charge and think through the implications I get quite worried.

[matty40s]

I went from West to East London recently along the Regent and then Ducketts. There was a strong (cold) easterly wind blowing and every lock I left had both it's lower gates blown completely open as I left(in fact, most locks I didn't need to open a gate, the wind opened both for me. After Camden 2nd lock, I gave up trying to close them. This often affects the Buckby flight too. and ALWAYS on teh Leicester line descending towards Kilby from Saddington.

[alan_fincher]

I went from West to East London recently along the Regent and then Ducketts. There was a strong (cold) easterly wind blowing and every lock I left had both it's lower gates blown completely open as I left(in fact, most locks I didn't need to open a gate, the wind opened both for me. After Camden 2nd lock, I gave up trying to close them.

Yes,

 

If anybody can reliably find a way of getting bottom gates to stay shut at locks like Hawley or Old Ford, (other than by drawing paddle at the top, or roping the handrails together!), I'd like to know how.

 

Never even try at those now!

 

And as you say some of Buckby is no better.

[magpie patrick]

an anecdote rather than an argument for or against.

 

Several years ago (1994?) I traveled from my home in Cardiff to Watford, by car, to meet my father, who had traveled by train from home, we were off to the big match, Borehamwood V Chorley in the FA trophy last 16.

 

Before the match we bought takeaway food and sat next to one of the Cassiobury Locks to eat it, I can never resist looking into a lock chamber, and so I stepped up to the edge and looked in. There were two swans paddling backwards and forwards. Not agitated, but clearly not happy. I tried to push a bottom gate open, probably six inches of water in the lock, so not a hope. I didn't have a windlass, but with gloved hands I managed to get one bottom paddle about an inch open by twisting the shaft that links spindle and paddle. I went back to finish my cup of tea.

 

Tea drunk and food eaten, the crack in the paddle had drained the lock, and I got dad to have some bread ready to tempt the swans out as I opened the gate. It wasn't needed. As soon as the gate was wide enough open for them to fit through, they serenely paddled through it and were on their way.

 

I think what had happened was they'd gone to sleep in a full lock the previous night, and it had emptied on them. It was February, so not much boat traffic, perhaps that last six inches would never have drained out, so they may have been stuck a few days. If the top gates had been left open they wouldn't have got stuck, but that lock full, and more would have leaked downstream.

[Midnight Rider]

Yes, there has always been views for & agin & I don't really care ------ as long as everyone does the same thing -------

 

So, if BW, the hire companies & the various waterways 'clubs' don't go for a change, it won't work.

 

Tony

[Ray]

I have two views on this.

 

Firstly as a very regular user of a short section of the GU for some 25 years working on trip boats I got to understand which locks leaked and which gates were worst so I would happily leave gates open when I knew that it made no difference shutting them. Equally, where there were short pounds above the locks and gates leaked, I would try to ensure that I always closed the gates that minimised the risk of draining the higher pound.

 

Two years ago we went from Marsworth to Hertford and back. With the exception of the Marsworth flight in both directions, we worked through every lock on our own and if I recall correctly, 95% or thereabouts were against us - that's around 190 out of 200. In many cases the far end gates were left open when we arrived. That was hard work, especially as we'd always been told to close all gates when leaving a lock, which we usually did, including on the Lee where we knew no better.

 

Returning now to the OP, some gates are hard to open/close and some as Alan says will swing open behind you. However, in the case of top gates, that can depend on how you exit the lock and where you stop to pick up your crew after they've worked the lock.

[ymu]

On a slightly pedantic note ... the fact that some gates won't stay shut isn't really relevant. If it hasn't been sorted, it clearly isn't a problem, and if it is a problem that has yet to be sorted, it's not something you can do anything about anyway.

 

The consequences of not closing a gate which needs to be kept closed are far, far worse than the inconvenience of having to open a few more gates yourself. If in doubt, close it. I can't see how that's at all controversial.

[Dovetail]

I move around on my own and the dog is of no help with the locks.

 

All I know is when I turn the corner and see the lock gate open for me it makes me happy and my life easier for that short time.

 

I do try to close as many gates as possible but the body and brain is not always willing.