Incident at Grindley Brook

[mark99]

Its not as if there is a lack of water..the Dee suppling it foc.

[Ex Brummie]

6 hours ago, zenataomm said:

Go on then I'll ask  .........

How? Surely they'd have to have been emptying the lock to get into that position?  Why were they doing that? Were they traversing the flight backwards?

I'm surely missing something here.

Some years ago, when there was a problem with the 1st lock after the staircase going down, I was descending, under the supervision of the permanent lockie, when as about to leave the bottom lock, a BW team arrived to rectify the fault and wanted to empty the pound. I was then taken backwards, back up the flight into the first lock with the intention of going back out. As I was just about to open the gate, the repair team gave a thumbs up, so I was then let back down again.

Some people struggle to complete the flight in a day, so three times in a day must be a record!!!!

[Nightwatch]

I've seen the level marks on the staircase in Chester but nowhere else.

[AndrewIC]

4 hours ago, tizzy said:

Nor do I recall any markings. They may have worn out.

There used to be white lines painted at "low water" on the sides of the top and middle chambers, but that was a good few years ago. There are still, I think, markers in the form of white(ish) strips fixed to the upper faces of the middle sets of gates, so not visible when the gates are open.

[cuthound]

On 2017-5-12 at 13:16, john6767 said:

Assuming they were actually going up, I can't see any reason to do down backwards there, there are really only two possibilities aren't there?  That water leaked out before they started to fill the locks, or that the bow got jammed on the top gates and it pushed the bow under.  At least in the middle of a staircase you can drain all the water out of the lock to stop it sinking.

Is this boat professionally crewed, or is it self hire?

It is self hire, as long as at least one of the party is disabled.

I skippered it in 2015 for a disabled friend.

Wirh regard to the sinking, another (remote) possibility is that an  over eager crew in the boat following opened the bottom paddles of the centre lock (their top paddles) and let the water out from under the boat.  I've seen people try to do that on a staircase.

[Paul C]

Think about it......you don't need a marking when you're going up.....you'll know the next lock is the same level as the previous by being able to open the gates, and you'll know the lock you're in is sufficiently full by looking behind or to the side of you just a few feet, to see the level of the water vs both the bank/side and/or the gates just behind you. It sounds like some water leaked out a bit (or the lock ahead wasn't completely full before emptying it into the lock the boat is in) but they opened the gates and drove forwards anyway, instead of letting some more water down to ensure clearance over the sill. Of course, 'a bit' less than full is okay for a shallow drafted boat, but not for a deeper boat, and of course the fact that a narrowboat is typically shallower at the front and deeper at its rear (like a gentle wedge shape) means that putting more and more power on going forwards means that the boat gets gradually but firmly stuck. Allow a bit more water to leak and you're into "tippy tippy" time.

[mark99]

But dont you need a mark to prevent exactly what you describe?

Ie say "4 foot water over top cill" mark.

 

Edited May 13, 2017 by mark99

[Paul C]

9 minutes ago, mark99 said:

But dont you need a mark to prevent exactly what you describe?

Ie say "4 foot water over top cill" mark.

 

No, because you're in the "full" lock, not the "empty" lock, so you can simply observe that the lock is full (or nearly full if you have a shallow drafted boat).

[mark99]

But is not the full lock a moving feast and not constant. Depends upon what level was in upper lock. 

Edited May 13, 2017 by mark99

[Paul C]

2 hours ago, mark99 said:

But is not the full lock a moving feast and not constant. Depends upon what level was in upper lock. 

I'm not sure what you mean, but no, it shouldn't be. It should be full once the level equalises and it should remain at that level when the boat is driven into the next chamber. Full means full. I am not sure if you are referencing the fact that the Grindley Brook staircase is a bit 'leaky' and it can need an additional little bit of water running down during operation, otherwise in the time it takes to traverse (for example) the first 2 chambers, you may need to 'top it up' a bit to prevent this - and that shallow drafted boats can "get away" with not topping it up during operation, if they don't dawdle. But basically no, full is full, infact moreso because of the leakiness:

 

The lock you're in (when going up) needs to be full when driving into the next chamber, it doesn't need to be made more complicated than this to safely do the lock.

Edited May 13, 2017 by Paul C

[mark99]

The points you are making are arguing for a level line. Not for use by fully aware boaters or perfectly full locks and sound gates but for a second quick check.

[Paul C]

The level line (to indicate the "nomal empty" level, as opposed to completely drained empty) is useful when going down, to prepare the locks for the passage. Eg when going down a triple chamber staircase the middle chamber would be at its normal empty level, and because the lowest chamber is also empty, there would be no convenient reference. It is not needed when going up because there's far better references to take the level from.

[mark99]

For instance = if single handed going up:

you float into middle chamber from lower chamber and close gates, climb up ladder fill middle lock from top lock, open gates

by the time you get back on board ready to move into top lock that could be enough time to allow leakage and expose you to the cill; and being on the boat you are not best placed to see the whole picture.

If there is a painted line inside middle lock indicating  "level above cill" it could be a handy check before you engage forward and wedge the boat on the cill.

Edited May 14, 2017 by mark99

[Paul C]

20 minutes ago, mark99 said:

 

If there is a painted line inside middle lock indicating  "level above cill" it could be a handy check before you engage forward and wedge the boat on the cill.

You don't need a painted line, because 1) the gates are right behind you and 2) the bankside is directly beside you, which would clearly indicate (if you looked at them and compared the water level) the level of the lock. No extra lines needed - in any case that line would be well forwards of where you are on the boat and probably shadowed by the boat, or lock wall structure except a limited viewing range, so not much use anyway. As I said before....think about it....you're ascending the lock(s).

[system 4-50]

Shirley what you need is a clear, easy-to-see, indication of whether the water level in the lock you are in is still going down, even if it is slowly. If it is, stay put and don't over the cill.  If it starts to go down after you start moving then you know its time to panic?

[mark99]

32 minutes ago, Paul C said:

You don't need a painted line, because 1) the gates are right behind you and 2) the bankside is directly beside you, which would clearly indicate (if you looked at them and compared the water level) the level of the lock. No extra lines needed - in any case that line would be well forwards of where you are on the boat and probably shadowed by the boat, or lock wall structure except a limited viewing range, so not much use anyway. As I said before....think about it....you're ascending the lock(s).

That presupposes one knows where the water level should be on the gate behind you/relative to ground level.

 

 

[mark99]

18 hours ago, Paul C said:

The lock you're in (when going up) needs to be full when driving into the next chamber, it doesn't need to be made more complicated than this to safely do the lock.

I agree but lets say a newbie fills the middle lock from the top lock but the top lock was not full. He thinks the middle lock is full. But the middle lock is not full....... all that has happened is that he can open the gates as levels have equalised thereby bringing the cill possibly into play.

Edited May 14, 2017 by mark99

[magpie patrick]

1 hour ago, mark99 said:

That presupposes one knows where the water level should be on the gate behind you/relative to ground level.

 

 

You do: nearly at the top if the gate without actually overflowing. 

Why do people try and be clever: play safe and fill the lock properly, none of this "you'll be alright with less" 

[mark99]

38 minutes ago, magpie patrick said:

You do: nearly at the top if the gate without actually overflowing. 

Why do people try and be clever: play safe and fill the lock properly, none of this "you'll be alright with less" 

 

 

Two things.

1)  There is a bit of history re the Lockie perhaps doing this very thing, I certainly grinded out when in a shallow drafted hire boat under a lockie control (a long time ago now)

2) Simple ignorance as pointed out in the post previous to yours which is not being clever but being fooled because gate opened.

Edited May 14, 2017 by mark99

[ditchcrawler]

On 2017-5-12 at 13:37, Stormbringer said:

In my experience the lockies do tend to run minimum water levels. We grounded on the cill going up last autumn and the lock keeper legged up and let some water down pretty sharpish..he said it was pretty normal for boats to drag on the cill between the locks ! We are not a deep boat either....

I didn't enjoy the experience much to be honest.....

That hasn't been the case today. The lock keeper filled the top chamber and also the middle one before boats started ascending.

[ditchcrawler]

On 2017-5-14 at 14:14, mark99 said:

For instance = if single handed going up:

you float into middle chamber from lower chamber and close gates, climb up ladder fill middle lock from top lock, open gates

by the time you get back on board ready to move into top lock that could be enough time to allow leakage and expose you to the cill; and being on the boat you are not best placed to see the whole picture.

If there is a painted line inside middle lock indicating  "level above cill" it could be a handy check before you engage forward and wedge the boat on the cill.

Like this

[mark99]

23 minutes ago, ditchcrawler said:

Like this

Yes!

[ditchcrawler]

23 minutes ago, mark99 said:

Yes!

They are not painted but plastic strips attached to the gates where the level is if you drop a full chamber from above. I suppose the danger could be if the lock chamber above had leaked off and you don't realise it.

[Paul C]

3 hours ago, ditchcrawler said:

Like this

If you were going up and about to go from the lower chamber to middle (or, middle to top) then the gates would be open and you'd not see those markers because they would be against the wall. The markers are there to set the level of the middle chamber to "normal empty" when going down the locks.

[nebulae]

Watched a hire boat a few years ago. Many people winding everthing in sight, resulted in the boat scraping over the cill,It then jammed before the rudder cleared the gates. Many willing hands closed the gates before other willing hands opened the top paddles.I suggested that it might be a good idea to close the paddles and release the boat.Bit of a Fred Carno. No idea where the locky was. Probably turned his back for a minute.Fortunately,no harm done.