Nobody hurt thankfully

[mayalld]

 

You'd have to have one hell of a leak on the bottom gates, coupled with standing about like a spare part and doing nothing about being stuck on the sill halfway out of the lock for that to happen. The struggle there would have been to get the top gate open should also have alerted those working the lock to the bottom end leakage, before even attempting to get the boat out into the pound. No real comparison at all with the speed at which things can get out of hand if you get hung up on the cill going downhill.

 

In the case of the lock where these problems have occurred;

 

1) There is a fairly severe leak on the bottom gates

2) As the upper pound gets lower, the top gate seal is no longer what it was, so opening the top gate isn't as hard as it might otherwise be.

3) Whilst they should have been alert to the leakage, the fact that you (with considerable experience as I understand it) dismissed getting grounded on a top cill whilst passing over it as "an inconvenience" suggests that the potential danger of this situation isn't always apparent (it wasn't apparent to you)

4) The lock above has all paddles locked with anti-vandal locks, which critically delays drawing water down.

[phill]

 

You'd have to have one hell of a leak on the bottom gates, coupled with standing about like a spare part and doing nothing about being stuck on the sill halfway out of the lock for that to happen. The struggle there would have been to get the top gate open should also have alerted those working the lock to the bottom end leakage, before even attempting to get the boat out into the pound. No real comparison at all with the speed at which things can get out of hand if you get hung up on the cill going downhill.

 

whereas I acknowledge your experience on the Trent, your knowledge of the Huddersfield narrow is sadly lacking.

 

http://waterwaynews.blogspot.co.uk/2013/08/photograph-of-latest-huddersfield.html

 

[nb Innisfree]

 

I've been in exactly this situation at Rushall - going uphill into a low pound and getting stuck coming out of the lock - noting bad happened, it was a pain in the arse that involved a lot of walking and letting a lot of water down right enough. With the benefit of hindsight though, it could have been quite bad as I (on my own) buggered off to the top of the flight to get water and left the boat where it was. That said, the way my boat's ballasted (front up) if all of the water had leaked from the lock I think the boat would've tipped forwards out of the lock rather than backwards into into.

Yes you was lucky the lock didn't drain quickly.

 

Risk of getting stuck is greater if the boat is on a more even level fore and aft as the wedging action is greater as the boat moves forward.

[Sabcat]

Yes you was lucky the lock didn't drain quickly.

 

Risk of getting stuck is greater if the boat is on a more even level fore and aft as the wedging action is greater as the boat moves forward.

Faced with the same situation again I think I'd get the boat back into the lock or better still, take note of the amount of water in the pound above before trying to get out of the lock in the first place. It has simply never occurred to me that this could be a problem.

[Tony Dunkley]

It all depends, the pound can be low due to badly leaking bottom gate, water level is dropping all the time so once the bottom plate is on the cill it becomes increasingly difficult to get it off. The only solution then is to let water down from the next pound which would have to be close by to be effective in time.

 

Dismiss the danger at your peril.

Thanks for the warning, but it's about fifty years too late. If you find your self in this situation though, drop both top (ground) paddles and hold back (full power astern) hard for a couple of seconds and then ease the revs down, the resulting "flush", kept in the lock by the closed paddles, will quite likely lift the boat enough to get it moving back into the lock again and off the cill.

Edited September 29, 2014 by tony dunkley

[Tacet]

It all depends, the pound can be low due to badly leaking bottom gate, water level is dropping all the time so once the bottom plate is on the cill it becomes increasingly difficult to get it off. The only solution then is to let water down from the next pound which would have to be close by to be effective in time.

 

Dismiss the danger at your peril.

The added problem is that letting water down helps little (once stuck on the cill) and could even accelerate the process. If the top paddles are gate paddles only, the grounded boat will form a good stopper to prevent the water reaching behind the boat, where it is needed to replenish that being lost through the leaky bottom gates. Raising the pound may only serve to raise the bow.

 

You are in with a better chance with ground paddles.

 

Frankly, I don't know what the entire answer is. "Don't leave the lock until you have plenty of water over the top cill" sounds good but overlooks the rate at which the level behind the boat may fall, particularly once the boat moves over the cill and restricts the flow behind the boat. It is also not entirely practical on some flights (like Huddersfield Narrow) where water is often short, and drawing down plenty only exacerbates the position in the next pound.

[nb Innisfree]

Faced with the same situation again I think I'd get the boat back into the lock or better still, take note of the amount of water in the pound above before trying to get out of the lock in the first place. It has simply never occurred to me that this could be a problem.

If it's low we take a depth reading at the cill with a pole before exiting.

 

Yes that is the prob here, because it's a relatively rare event compared to the more usual cilling, folk don't realise the danger.

 

ETA: If the water level is below the normal mark after ascending, leave the boat in the lock, get off and investigate making sure the boat is well back from the cill.

Think, think and think again!

Edited September 29, 2014 by nb Innisfree

[nb Innisfree]

The added problem is that letting water down helps little (once stuck on the cill) and could even accelerate the process. If the top paddles are gate paddles only, the grounded boat will form a good stopper to prevent the water reaching behind the boat, where it is needed to replenish that being lost through the leaky bottom gates. Raising the pound may only serve to raise the bow.

 

You are in with a better chance with ground paddles.

 

Frankly, I don't know what the entire answer is. "Don't leave the lock until you have plenty of water over the top cill" sounds good but overlooks the rate at which the level behind the boat may fall, particularly once the boat moves over the cill and restricts the flow behind the boat. It is also not entirely practical on some flights (like Huddersfield Narrow) where water is often short, and drawing down plenty only exacerbates the position in the next pound.

Yes it is a difficult one, beeing keen to get out of the lock into the seemingly safe pound is the prob I think. Instead consider the choice, suffer the inconvenience of a possibly long delay before carrying on or have your boat wrecked!

And as illustrated in an earlier pic, going forward into a lock from a low pound carries the same risk.

Edited September 29, 2014 by nb Innisfree

[Just Heaven]

Bear with me as I'm very new to this, but surely you should notice that something was going wrong long before the boat got to that angle and just close the paddles?

 

We have been boating for 20 years, and have done several thousands of locks, but earlier this year on the Soar, not far from Kegworth, we had the front edge of our boat get caught on the lock side. The stern dropped but not the bow. By the time I had noticed and got to the paddles it was at quite an angle, but all was ok.

 

Steve

[Tony Dunkley]

 

whereas I acknowledge your experience on the Trent, your knowledge of the Huddersfield narrow is sadly lacking.

 

http://waterwaynews.blogspot.co.uk/2013/08/photograph-of-latest-huddersfield.html

 

 

You're right there, I' never been on the Huddersfield. During the time I spent working narrowboats, I believe it was closed and derelict anyway. But I stand by what I said . . . a leak in the bottom gates bad enough to drain even a short pound quickly enough to cause this, should not have gone unnoticed by whoever's working the lock.

In fact, I've had motors in the position shown in the top picture on many occasions, but it was done deliberately for the purpose of getting rubbish such as wire or spring mattresses or tyres and the like off the blades(propellor).

Edited September 29, 2014 by tony dunkley

[Paul C]

 

You're right there, I' never been on the Huddersfield. During the time I spent working narrowboats, I believe it was closed and derelict anyway. But I stand by what I said . . . a leak in the bottom gates bad enough to drain even a short pound quickly enough to cause this, should not have gone unnoticed by whoever's working the lock.

 

What if that person was singlehanding and had walked/run to the lock above, to let water down?

[mayalld]

 

You're right there, I' never been on the Huddersfield. During the time I spent working narrowboats, I believe it was closed and derelict anyway. But I stand by what I said . . . a leak in the bottom gates bad enough to drain even a short pound quickly enough to cause this, should not have gone unnoticed by whoever's working the lock.

 

Which puts it in exactly the same category as cilling a boat in the conventional way.

 

Either is an error on the part of the boater.

[Tony Dunkley]

 

What if that person was singlehanding and had walked/run to the lock above, to let water down?

 

Don't leave the boat stuck on the top cill before going up to run some water . . . pull it back into the chamber clear of the cill and tie it there before leaving it.

[Emerald Fox]

"It is essential to keep the boat under surveillance every second when locking." - Margaret Cornish, 'Troubled Waters'

[Tony Dunkley]

 

Which puts it in exactly the same category as cilling a boat in the conventional way.

 

Either is an error on the part of the boater.

No, because the top gate is open, and even with a boat stuck on the cill, water can still run into the chamber between the sides of it and the walls/gate, helped by leaving the ground paddles up. It's all going to happen a lot slower than when a boat gets hung on the cill when emptying a lock.

[phill]

No, because the top gate is open, and even with a boat stuck on the cill, water can still run into the chamber between the sides of it and the walls/gate, helped by leaving the ground paddles up. It's all going to happen a lot slower than when a boat gets hung on the cill when emptying a lock.

 

That might be true but stopping it isn't as simple as with a cilling.

 

There's a lock in Bath, scene of a few hire cill-related sinkings where the bottom paddles used to be hydraulic and impossible to shut against the force of water once open. Thankfully since changed.

[mayalld]

No, because the top gate is open, and even with a boat stuck on the cill, water can still run into the chamber between the sides of it and the walls/gate, helped by leaving the ground paddles up. It's all going to happen a lot slower than when a boat gets hung on the cill when emptying a lock.

 

There is none so blind as those that will not see!

 

Cilling a boat (which is to say, sitting the skeg on the cill) is generally understood, even by those who do it, to be a big problem that requires immediate action.

 

Grounding on the upper cill whilst passing over it is dismissed as "an inconvenience", even by those with a fair bit of experience. Even if the situation unfolds fairly slowly, by the time you realised that this was more than just inconvenient, you are probably stuck fast, and the boat is sat there making it VERY difficult to raise levels in the chamber as fast as you would like.

[Sabcat]

This is pretty much exactly what I did, stuck fast coming out. Didn't see it as any kind of danger at all, climbed out and went strolling off up to the top of a 9 lock flight letting water down all the way (every single pound was almost empty). It was well over an hour before I took any notice at all of what my boat was doing and maybe more. It didn't occur to me at all it might be a problem other than the one I already had.

[Tony Dunkley]

 

There is none so blind as those that will not see!

 

Cilling a boat (which is to say, sitting the skeg on the cill) is generally understood, even by those who do it, to be a big problem that requires immediate action.

 

Grounding on the upper cill whilst passing over it is dismissed as "an inconvenience", even by those with a fair bit of experience. Even if the situation unfolds fairly slowly, by the time you realised that this was more than just inconvenient, you are probably stuck fast, and the boat is sat there making it VERY difficult to raise levels in the chamber as fast as you would like.

 

To get to this situation you would have to first not notice how low the pound is and fail to notice the leak at the bottom end, secondly, be unaware of what your own boat draws and get stuck part way out of the lock, and then stand gawping and not doing anything about it. Anyone putting up that sort of performance should really give some serious thought to taking up a different pastime.

Having said all that, I do agree that an awful lot of pleasure boaters I've seen in action do go about their boating blissfully unaware of whats happening around them and just how quickly things can start going badly wrong if they don't pay enough attention to what they're doing.

Edited September 29, 2014 by tony dunkley

[mayalld]

 

To get to this situation you would have to first not notice how low the pound is and fail to notice the leak at the bottom end, secondly, be unaware of what your own boat draws and get stuck part way out of the lock, and then stand gawping and not doing anything about it. Anyone putting up that sort of performance should really give some serious thought to taking up a different pastime.

 

Tony,

 

actually, all that is required to get into this situation is a belief that grounding whilst passing over a top cill is "an inconvenience" (which is what you suggested that it was), as opposed to "dangerous", which most people understand a cilling to be.

 

Clearly, if people understand that it is more than an inconvenience, they will (the instant that the feel the boat touch the cill) back off.

 

Those who think it merely inconvenient will not react in time.

[bizzard]

If boats were equipped with say a sailing dinghy centreboard case and slot right up in the bow end with a daggerboard or backward pivoting centreboard in it with a nicely rounded leading bottom edge which protruded down a few inches below the boats baseplate. This centreboard would strike the locks upper cill first when leaving the dodgy looking lock, jump up and actuate either an electrical contact to sound a warning siren or buzzer or could simply be rigged up with string and pulleys to ring a nice little bell near the helm position as a warning of the danger. The centreboard or daggerboard can be cleated off in the up position when not in use. This centre board would also give many inland waterways boats extra directional stability when travelling forwards in strong winds (no more crabbing along) and would make going astern a doddle as the board will act as a fixed rudder up front to stop the bow end drifting or blowing willie-nilliley off course.

[Tony Dunkley]

 

Tony,

 

actually, all that is required to get into this situation is a belief that grounding whilst passing over a top cill is "an inconvenience" (which is what you suggested that it was), as opposed to "dangerous", which most people understand a cilling to be.

 

Clearly, if people understand that it is more than an inconvenience, they will (the instant that the feel the boat touch the cill) back off.

 

Those who think it merely inconvenient will not react in time.

 

You know what, . . . I think there's a real risk here that we might end up agreeing about something.

[David Mack]

a leak in the bottom gates bad enough to drain even a short pound quickly enough to cause this, should not have gone unnoticed by whoever's working the lock.

 

In a case like the picture below with the boat travelling downhill, the boater might well not be aware how quickly the water is leaking through the bottom gates. Without the boat there the whole pound will be dropping, but not quickly enough to be obvious. But once a flat bottomed, vertical sided narrowboat has touched on the cill, it will be almost completely blocking the flow of water from the pound into the lock chamber. At this point the water level in the lock itself will drop much quicker, and as soon as the boat has tilted even slightly there is not a cat in hell's chance of pulling the boat back off with the engine or by heaving on ropes.

 

There is nothing the crew can do to reduce the flow out of the lock, and bringing water down from above will increase the level in the pound, but not much will find its way into the lock, and as the boat tilts and the stern comes out of the water there is less flotation, and so no chance of floating the stern off.

 

The result is inevitable.

[bizzard]

If boats were equipped with say a sailing dinghy centreboard case and slot right up in the bow end with a daggerboard or backward pivoting centreboard in it with a nicely rounded leading bottom edge which protruded down a few inches below the boats baseplate. This centreboard would strike the locks upper cill first when leaving the dodgy looking lock, jump up and actuate either an electrical contact to sound a warning siren or buzzer or could simply be rigged up with string and pulleys to ring a nice little bell near the helm position as a warning of the danger. The centreboard or daggerboard can be cleated off in the up position when not in use. This centre board would also give many inland waterways boats extra directional stability when travelling forwards in strong winds (no more crabbing along) and would make going astern a doddle as the board will act as a fixed rudder up front to stop the bow end drifting or blowing willie-nilliley off course.

A similar device could be fitted to airliners as an aid for landing in foggy weather. Like so (Foggy weather automatic landing device).

If a great long stick hinged at the front end under the aircrafts fuselage with a little rubber tyred caster wheel under its trailing end were lowered on a string by the pilot on the landing approach in foggy weather the caster wheel would hit the runway first and by rigging and connecting the stick with more string to the planes control column and throttle levers could be arranged to automatically pull the column back, shut the throttles flair out and land the aircraft safely with virtually no pilot input at all apart from lowering the device at the right moment. The stick would look nicer if made of bamboo and varnished.

I shall be in contact with Airbus in Toulouse France urging them to fit this wonder device to their latest airliner which is under trials at the moment ( The Airbus A350) Airbuses answer to Boeings Dreamliner.

[Tony Dunkley]

 

In a case like the picture below with the boat travelling downhill, the boater might well not be aware how quickly the water is leaking through the bottom gates. Without the boat there the whole pound will be dropping, but not quickly enough to be obvious. But once a flat bottomed, vertical sided narrowboat has touched on the cill, it will be almost completely blocking the flow of water from the pound into the lock chamber. At this point the water level in the lock itself will drop much quicker, and as soon as the boat has tilted even slightly there is not a cat in hell's chance of pulling the boat back off with the engine or by heaving on ropes.

 

There is nothing the crew can do to reduce the flow out of the lock, and bringing water down from above will increase the level in the pound, but not much will find its way into the lock, and as the boat tilts and the stern comes out of the water there is less flotation, and so no chance of floating the stern off.

 

The result is inevitable.

It certainly won't with the ground paddles down, as they are in this picture, they should have been lifted as soon as the boat got fast on the cill, then the level in the chamber wouldn't drop any quicker than the pound was doing.

Edited September 29, 2014 by tony dunkley