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Leaving gates open


biggles47

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Not so much flood water, just normal flow.

The topgates were designed to assist the weirs with the flow over them. Because the guillotine gates are higher than the topgates, leaving that closed will muck up the level on that particular reach of the river.

However, the EA have added planks to a lot of them to lessen the flow (e.g. Titchmarsh) and there is a lot of debate locally about whether that's good or bad.

That makes more sense, but if that is the only reason for having to leave them up, it don't think that is good enough. The top of he guillotine should be at correct level, if what you say is true it is just bad design and the EA should be ashamed of themselves for accepting the poor design. I have to say I had assumed that they did not want the guillotine gate left under water and that was the reason for leaving them up, but just wasting time and electricity to fix a poor design is rediculous.
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That makes more sense, but if that is the only reason for having to leave them up, it don't think that is good enough. The top of he guillotine should be at correct level, if what you say is true it is just bad design and the EA should be ashamed of themselves for accepting the poor design. I have to say I had assumed that they did not want the guillotine gate left under water and that was the reason for leaving them up, but just wasting time and electricity to fix a poor design is rediculous.

 

The guillotines were designed in the 1930's, until then the Nene was a very poor navigation with the locks in decay and a number of staunches in the lower (and much less used) reaches towards Peterborough.

 

The locks then were primarily a flood alleviation scheme that could be navigated, presumably because there was no appetite for the legal process to close the navigation and it was easier to make combined structures than separate locks and sluices

 

As an aside, and I am having a bit of a pop here, I do wish people would have at least some idea that virtually none of our present navigations were built for leisure nor were they built by the organisations that now operate them

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I doubt that the structures that are there today are from the 30s are they? But either way I don't see why they could not be modified to work properly if them being a different height to the top of the gate by a few inches is the only issue that causes such a massive inefficiency.

 

I don't see it matters if they were built for leisure or not nor who built them, the only thing that matters is if they are fit for purpose or not.

 

Edited to add; not having a go at anyone on here, I just hate bad design.

Edited by john6767
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The basics on the guillotine locks are still 1930s. The NRA as was were struggling with them in the early 90s as they started to wear out. A whole new mechanism costs a lot and thus the guillotine often gets replaced with mitre gates: that's not cheap either!

 

I haven't looked in detail but I would guess altering the height of the top of the guillotine is less than straightforward

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The basics on the guillotine locks are still 1930s. The NRA as was were struggling with them in the early 90s as they started to wear out. A whole new mechanism costs a lot and thus the guillotine often gets replaced with mitre gates: that's not cheap either!

I haven't looked in detail but I would guess altering the height of the top of the guillotine is less than straightforward

I can't see why it would be that hard to shorten if they wanted to do it. I notice that a few have been made taller, with bits bolted on the top.

 

The Nene only has 5 I think with mitre bottom gates, one being the contender for the worst designed lock I have seen so far, Lower Wellingborough.

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The maths are fairly simple.

 

If we exclude the case where an approaching boat from the other direction can be seen (in which case we are all agreed that gates should be left open), and consider the case where everybody leaves a lock not knowing whether the next boat will be coming the same way or the opposite way.

 

Let us also not consider the various moves along the lock, and consider instead just the number of times the gates must be operated.

 

There are effectively two different regimes - "Close 'em up" and "leave 'em open", so we need to consider 4 different cases;

 

1) The rule is "close", and all boaters follow the rule

2) The rule is "close", and a single boater doesn't follow the rule

3) The rule is "open", and all boaters follow the rule

4) The rule is "open" and a single boater doesn't follow the rule.

 

Case 1 is the current situation, and it has a satisfying degree of equality.

All boaters have exactly 4 gate operation operations to perform.

 

Case 2 is the current situation, but with some people arbitrarily deciding to change the rules that apply to them.

It works well for the maverick, because he will always save one gate operation, and will have to operate a gate 3 times.

The following boater (following the rules) will have either 3 or 5 gate operations, so may lose out, but on average will not.

 

Case 3 is the sunlit uplands of what will happen if all leaks are fixed, and we move to "leave 'em open"

If you arrive at a lock set for you, you will have just 2 gate operations, a distinct saving.

If you arrive at a gate set against you, you will have 4 gate operations, no more than now.

 

Case 4 is the same, but some people will cling to what they know

The rebels will have 3-5 gate operations.

The conformers following a rebel will have 3 gate operations.

 

So, the upshot is;

 

If the underlying reasons for closing gates was fixed, it would make life easier for all if we left gates open when no other boats could be seen. Individuals adopting this practice gain for themselves, but may cause extra work for those who follow the rules.

 

For the time being, the reasons for shutting gates hold sway, notwithstanding the time and motion analysis above.

 

No doubt true - but can be simpler expressed:

 

The leave-them-open method never requires a gate to be closed only then to be opened in immediate succession..

 

The close-them-all method sometimes requires a gate to be closed only then to be opened in immediate succession.

 

Sometimes is about 50% - discounting the seeing-you-coming and one-way traffic etc situation.

 

 

 

Do those who think (is there anyone left?) that always closing gates is no more work/action close the gates in the face of a boat approaching? After all, according to them, it is no more work overall.

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Do those who think (is there anyone left?) that always closing gates is no more work/action close the gates in the face of a boat approaching? After all, according to them, it is no more work overall.

It is more work overall but that is not the point, the point is to prevent folk arriving at locks to find drained or very low pounds. If your primary concern is to minimise work I'd recommend staying on your sofa and watching telly.

 

And I'd also mention that just considering long term average work is not the whole picture. If you are going up a flight of 20 locks and have to close the other end gate on every one, it is not much consolation that sometime in the next 10 years you will be going up the same flight finding all the entrance gates open.

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It is more work overall but that is not the point, the point is to prevent folk arriving at locks to find drained or very low pounds. If your primary concern is to minimise work I'd recommend staying on your sofa and watching telly.

 

And I'd also mention that just considering long term average work is not the whole picture. If you are going up a flight of 20 locks and have to close the other end gate on every one, it is not much consolation that sometime in the next 10 years you will be going up the same flight finding all the entrance gates open.

 

 

On your first point, those that like pointlessly opening and closing gates are welcome to find a spare lock and do so till their hearts are content. I much prefer to be working a lock than sitting on a sofa, but part of that enjoyment is doing it efficiently.

 

On the second para, the immediate consolation is not having to close-up after your boat has left the lock. There may well be other, good reasons for closing gates but leaving them open (universally) can never make more work and on some occasions less.

Edited by Tacet
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On the second para, the immediate consolation is not having to close-up after your boat has left the lock. There may well be other, good reasons for closing gates but leaving them open (universally) can never make more work and on some occasions less.

If your priority is laziness then I'd just mention that closing the far end gate(s) before filling / emptying is far more work than closing up the near-end gates after you leave the lock. With the former, you have to walk 72'x2 = 144' or With the latter you just have to walk a few feet. That translates to walking an extra kilometre over a flight of 23 locks.

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It is more work overall but that is not the point, the point is to prevent folk arriving at locks to find drained or very low pounds. If your primary concern is to minimise work I'd recommend staying on your sofa and watching telly.

 

And I'd also mention that just considering long term average work is not the whole picture. If you are going up a flight of 20 locks and have to close the other end gate on every one, it is not much consolation that sometime in the next 10 years you will be going up the same flight finding all the entrance gates open.

Coming to a flight with a "bad Road" if gates are left open is exactly the same number of lock gate movements as it is nowadays with the "close up" rule in place, because you can leave it open when you leave:

 

bad road- close top gates, open bottom gates, close bottom gates, open top gates.

 

Closed up- open bottom gates, close bottom gates, open top gates, close top gates.

 

The further time and efficiency savings with leaving gates open is you never have a part-filled lock you have to refill or drain off, the locks are always entirely full or entirely empty.

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Coming to a flight with a "bad Road" if gates are left open is exactly the same number of lock gate movements as it is nowadays with the "close up" rule in place, because you can leave it open when you leave:

bad road- close top gates, open bottom gates, close bottom gates, open top gates.

Closed up- open bottom gates, close bottom gates, open top gates, close top gates.

 

Snipping from your above and with the presumption of going up:

 

Top bottom bottom top

 

Vs

 

Bottom bottom top top

 

Notice the difference? (Hint - each transition from bottom to top or vice versa = walking 72' or so)

 

But actually the first is worse since you arrive at the bottom so it's

 

(Arrive)bottom top bottom bottom top

 

Vs

bottom bottom top top

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Lock gate movement is not a particularly accurate way of measuring effort involved for working locks. Nick has now introduced distance walked, but I would suggest that the number of times you must stop the boat for someone to get on/off is a significant factor too. The steps are too many to detail as they depend largely on whether or not you have crew and the type of lock, but they always include stopping to draw paddles if required and open the gates to enter and stopping to close paddles and shut the gates on exit. One or other of these steps becomes unnecessary if exit gates were left open as the norm.

 

The same would hold true if there were lock keepers at each lock or if all boats had someone lock-wheeling for them. Reintroduction of lock keepers is not likely to happen; perhaps it should be a condition that all boaters had crew to lock-wheel laugh.png

 

Tam

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I would suggest that the number of times you must stop the boat for someone to get on/off is a significant factor too.

As the person who works the locks we don't stop for me to get off. I either step off in the bridge nearest the lock or from the boat coming close in to the side.

 

Getting on the boat "lurks" just out side the gates for the short time it takes me to close the gates.

 

Not a significant factor IMO

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As the person who works the locks we don't stop for me to get off. I either step off in the bridge nearest the lock or from the boat coming close in to the side.

 

Getting on the boat "lurks" just out side the gates for the short time it takes me to close the gates.

 

Not a significant factor IMO

It's not significant if you're boating efficiently.

 

It is if people insist on pulling in every time to the lock landing stage (a new invention) and doing knitting with the bow and stern lines, or just generally faff about- and then inanely grin and go on about "if you're in a hurry, you're on the wrong transport system" or "slow down, this is meant to be relaxing!" or something.

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Nene is because the top gates act as a weir, wont happen with guillotine as its to high.

Being really picky Thames locks should be left with all gates closed and empty

 

And my theory for this rule is that it means less slime on the side of the lock walls. One of the lockkeepers' duties is to give them a scrub once a week, I think?

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As the person who works the locks we don't stop for me to get off. I either step off in the bridge nearest the lock or from the boat coming close in to the side.

 

Getting on the boat "lurks" just out side the gates for the short time it takes me to close the gates.

 

Not a significant factor IMO

 

Except that you ALWAYS have to get off to open the entry gates even if the levels mean the lock should be in your favour**. The boat also always has to stop for you to get back on after dropping the exit paddles and shutting those gates. I did also say it depends upon the boat and the locks in question - it is not always so easy to stop to pick someone up if it is very windy or if the canal is shallow there, plus locks with paired gates involves someone crossing to shut them both.

 

F2S is correct that there are ways of achieving this which are more efficient than others, but it is still overall more ergonomic to leave exit gates open and I believe this is the element currently under debate. The efficient boaters are probably also those who look at what they are doing. These are the ones who can actually look at what is happening and would shut the exit gates when they leave if the other ones are leaking, as used to happen "in the good old days" before the one-size-fits-all recommendation to shut ALL gates.

 

Tam

 

edit to add footnote **unless you nudge gates open with the fore end when travelling uphill, but this is probably another hare to set running.

Edited by Tam & Di
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If your priority is laziness then I'd just mention that closing the far end gate(s) before filling / emptying is far more work than closing up the near-end gates after you leave the lock. With the former, you have to walk 72'x2 = 144' or With the latter you just have to walk a few feet. That translates to walking an extra kilometre over a flight of 23 locks.

 

I'm not sure which way you're arguing. Are you advocating the lazy way or the additional work way? And which is which?

 

In terms of walking, in the same flight of 23 locks you mention how do you set ahead and close-up when single or two-handed? Does not someone have to walk back from the subsequent lock to close-up, or does the steerer do it? If the steerer does it by pausing outside the lock, the boat is slowed. If someone comes back, then that's nearly the length of the whole flight x 2 extra walking which will be rather more than 1km, which assumes an entirely bad road in any event.

 

If you are mob-handed, it is a different matter.

 

There are other reasons for closing up, which I can accept, but overall efficiency of working locks isn't one.

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It's been discussed on here many times. Points raised for and against include:

 

For leaving open:

 

- Less work overall since it's 50/50 which way the next boat will be coming from.

- It's how they used to do it.

- It's a pain to close gates behind you when single handing.

 

For closing:

 

- It's the rules.

- Leaving open when everyone else closes is selfish.

- It causes pounds to drain through leaky gates.

- It's not 50/50 because changeover days at hire bases lead to lots of boats all heading the same way.

 

Countering this from the open people:

 

- CRT should fix the leaky gates.

- It would be selfish if we all left them open.

 

Countering back:

 

- Yes, but it's the RULES!

- If you want the rules to be changed, then campaign for that, until then, stop being so bloody selfish and lazy.

 

My position is that lots of locks do leak and closing both ends of a lock helps to protect the pound above. For example, leave open the bottom gates at the bottom Factory Lock at Tipton and you WILL drain the pound above.

 

Also, it is currently selfish and lazy if you leave gates open while almost everyone else closes them. This mean you get the 50/50 chance of the lock being in your favour, you almost never have to close a gate when it's not in your favour but then also never bother to shut a gate behind you. This means that you will average less work per lock by encumbering other boats with additional work. If you can't understand the maths behind this, then I can't really help you any further.

Excellent summary.

 

Perhaps it should be pinned so that it can be referred to when this subject invariably pops up again?

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I'm not sure which way you're arguing. Are you advocating the lazy way or the additional work way? And which is which?

 

In terms of walking, in the same flight of 23 locks you mention how do you set ahead and close-up when single or two-handed? Does not someone have to walk back from the subsequent lock to close-up, or does the steerer do it? If the steerer does it by pausing outside the lock, the boat is slowed. If someone comes back, then that's nearly the length of the whole flight x 2 extra walking which will be rather more than 1km, which assumes an entirely bad road in any event.

 

If you are mob-handed, it is a different matter.

 

There are other reasons for closing up, which I can accept, but overall efficiency of working locks isn't one.

 

In this context I am not advocating either way, I am merely pointing out that any analysis of workload should include walking the length of the lock and not just the number of gate operations.

 

In the overall context, I am of course advocating closing gates on leaving canal locks in accordance with CRT's boater's handbook, the many signs on lock flights reminding us to do it, and the customer and practice of nearly all boaters - with exceptions of course when specifically signed otherwise and on canalised rivers.

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Re the Nene protocol.

 

It always used to be the case that the g

gate must be raised so as to maintain the correct level in times of NORMAL flows, not high flows. High flows (SSA) have always been controlled by reversing the lock.

Since the addition of the lintels to the vee gates the river no longer maintains its correct level, air draft has been reduced at several locations - most notably Islip and can cause boats to be stuck even when the river is not on SSA.

 

There are two reasons for the addition of the lintels.

 

1, to try and protect very long narrow boats from the over topping of the gates.

 

2, to get over the lack of dredging.

 

Both are short sighted as they lead to more problems than they solve.

 

We are in an era where those that call the shots at the EA have little or no insight into the impact the decisions they make have on those living near or using the river.

Thankfully the mad idea of leaving the river to its own devices instead of reversing and control the river at times if high flow (SSA) seems to have been quietly shelved.

 

The official reason now given for leaving the guillotine raised is to protect fish stocks.

 

Think yourself lucky you didn't boat on here when the only electrified lock was at Lower Barnwell!

 

Magpie is correct about the structures being the original 1930's ones.

Over the years Northampton, Brackmills, Wellingborough x 2 and Higham have been replaced.

If you look a lot of the casting was done by Allen's of Bedford, dad's mate was the son of the last Allen before it was sold off and ultimately shut.

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Thanks for that.

 

I have seen the signs about protecting fish, but leaving the top gates, rather than the guillotine, open would achieve the same thing.

It's funny, I've always accepted the requirement to leave the pen empty, even in summer when it seems a bit pointless.

It must come as a shock to those used to only having to close a gate (or not) on the canals :)

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