Nobody hurt thankfully

[mayalld]

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.

 

Interesting one to try to model!

 

When the boat grounded, with its stern in the forebay, not only did it offer a near perfect plug to stop water entering the lock, but it offers a significant obstruction to water reaching the ground paddles.

 

Only once it starts to pitch forward does it offer room for water to reach the ground paddles.

 

The question is "are the ground paddles open to water passge before the boat reaches tipping point"

[Scholar Gypsy]

Article in today's Metro .

 

I would have thought the boat was a bit soggy to continue its journey ...

[Mike Todd]

Where the front (or rear) fender is attached by chain, then one link should be sawn through (on one side if you get my meaning) to create a weak spot which, if caught on the gate, will give way.

Just so (although there are other ways of creating the 'weak link') Far more locks that is oft imagined are equally dangerous at the front as the back when going down. OK, so in very recent times BW rfeduced the risk by adding extra planks in the gaps but the risk is still very much present. I know - luckily our weak link prevented and other damage.

[Tony Dunkley]

In the course of this thread it's occurred to me to ask if it is the normal practice among pleasure boaters to check the gates behind you for leakage whilst working, and especially just before leaving a lock. It was something always done without fail at every lock by professional boatmen, almost subconciously, it only needs a glance, as part of the process of working a lock, partly to reduce the chance of pounds dropping behind you and also to make sure that none of the paddles were partially fouled and hadn't gone right down, slowing the lock from filling or emptying as fast as possible.

[ditchcrawler]

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

So true. We were helping friends down Atherstone and I was a head assisting a boat up the next lock towards us. As soon as the top paddles were open the chap who was working the lock just said "your OK with this, I'll walk up to the next one" He didn't know me from Adam, what my knowledge and experience was, but he was quite happy walking off leaving me incharge of his boat coming up in a lock with his wife on the tiller.

[Tony Dunkley]

 

Interesting one to try to model!

 

When the boat grounded, with its stern in the forebay, not only did it offer a near perfect plug to stop water entering the lock, but it offers a significant obstruction to water reaching the ground paddles.

 

Only once it starts to pitch forward does it offer room for water to reach the ground paddles.

 

The question is "are the ground paddles open to water passge before the boat reaches tipping point"

 

Rubbish . . . the swim is level with the ground paddles anyway.

[billh]

All the discussion seems to be about what boaters should or should not be doing when presented with a boat stuck on a cill with water falling rapidly.

There seems to be no mention of the navigation authorities requirement to maintain locks and lockgear to an acceptable standard. In the case of the above mentioned HNC, plus the Peak Forest and Ashton Canal , those responsible are failing big time. This might be due to lack of budget, shortage of staff, experience or whatever. The fact remains that lockgear remains faulty, useless or damaged for months if not years ( eg bottom gates and cills at Lock6 on the Ashton, leaks like a sieve). Their answer at HNC lock 9 as illustrated is to place a warning sign with coloured stop /caution/go markers at the top gate- the markers are now covered in mud so you can't see what colour is showing! Maybe stopping the gates/cills leaking would be a better idea?

Bill

[ditchcrawler]

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.

I think its pointless looking at photos after the event as they don't always indicate the status at the time of the incident. Look at the very short stern line on the cilled boat. Possibly put there to stop it sliding forward but may there when working the lock. We dont know, same with paddles, they may have been open, they may have been closed. I know when I go into a lock, somehow 18 tons of water manage to get out around the boat as I go in.

[David Mack]

 

Rubbish . . . the swim is level with the ground paddles anyway.

 

Depends how far into the lock he is when he grounds on the cill

[Tony Dunkley]

All the discussion seems to be about what boaters should or should not be doing when presented with a boat stuck on a cill with water falling rapidly.

There seems to be no mention of the navigation authorities requirement to maintain locks and lockgear to an acceptable standard. In the case of the above mentioned HNC, plus the Peak Forest and Ashton Canal , those responsible are failing big time. This might be due to lack of budget, shortage of staff, experience or whatever. The fact remains that lockgear remains faulty, useless or damaged for months if not years ( eg bottom gates and cills at Lock6 on the Ashton, leaks like a sieve). Their answer at HNC lock 9 as illustrated is to place a warning sign with coloured stop /caution/go markers at the top gate- the markers are now covered in mud so you can't see what colour is showing! Maybe stopping the gates/cills leaking would be a better idea?

Bill

Absolutely right . . . but any criticism of C&RT, justified or not, tends to upset certain members of this Forum . . . so yes, I think the entire system is beginning to revert back to the state of dereliction it was in after the last war . . . it's what C&RT mean when they talk about keeping people connected with History.

Edited September 29, 2014 by tony dunkley

[Tony Dunkley]

I think its pointless looking at photos after the event as they don't always indicate the status at the time of the incident. Look at the very short stern line on the cilled boat. Possibly put there to stop it sliding forward but may there when working the lock. We dont know, same with paddles, they may have been open, they may have been closed. I know when I go into a lock, somehow 18 tons of water manage to get out around the boat as I go in.

They wouldn't have started working the lock because they couldn't get into it.

 

Depends how far into the lock he is when he grounds on the cill

You can see how far in it was in the photo.

[ditchcrawler]

They wouldn't have started working the lock because they couldn't get into it.

 

They may have filled the lock to try and come in, it may have been open from a boat leaving, something else we dont know

[nb Innisfree]

I started this subject with the intention of warning anyone who may be unaware of the danger, if anyone chooses to dismiss it then that is their problem not mine.

[mayalld]

You can see how far in it was in the photo.

 

No you can't.

 

You can see how far in it was AFTER it reached tipping point.

 

As the level in the lock fell, and the boat went down by the head, it would have reached a point where the bow doors were overtopped and water flooded in.

 

Once that happened, the boat would almost certainly move further forward, so the position of the stern is NOT where it was when the events started to unfold.

[IanD]

It's easy for people to say "anyone with any knowledge wouldn't have done this".

 

We did the HNC west to east last year and had a great time, and fortunately I knew about the top cill problem via this forum. So when we did get stuck coming out of one of the locks (the one where boats had sunk) I realised what was happening, and by acting quickly we managed to get off the cill and reverse back into the lock to wait for CRT to run some water down the flight. But if I hadn't read about the sinkings I doubt that I'd have realised what was happening and how dangerous it was, in more than thirty years boating this had never happened to me before and I've never heard it mentioned as something to watch out for.

 

The sinking at the start of the thread is the much more common cill problem which everone should be aware of, but with only two people and a deep fast-emptying lock all it takes is a bit of lack of attention and maybe some complacency -- which 99% of the time wouldn't cause any problem -- and you can rapidly get into trouble, especially if you can't move too fast. At least this time nobody was hurt or killed, but there still seems to be rather too much schadenfreude in some postings for comfort...

[Tony Dunkley]

 

Interesting one to try to model!

 

When the boat grounded, with its stern in the forebay, not only did it offer a near perfect plug to stop water entering the lock, but it offers a significant obstruction to water reaching the ground paddles.

 

Only once it starts to pitch forward does it offer room for water to reach the ground paddles.

 

The question is "are the ground paddles open to water passge before the boat reaches tipping point"

 

Not so, . . . loaded boats get in and out of locks noticeably quicker with the top paddles up, allowing the displaced water better passage to run back out of or in to the lock chamber.

Edited September 29, 2014 by tony dunkley

[Paul C]

 

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.

 

Easier said than done. Assuming a constant water level, and therefore a constant depth over the exit cill, a narrowboat by virtue of its bow being quite shallow draft, the stern being deeper and its length, is a "wedge" shape of very slender angle in its underwater profile. And with the momentum of leaving the lock, its quite possible to get stuck going out of it, and there not be enough reverse thrust to reverse off the cill and back into the lock. Now add in the complication of a leaking gate gradually dropping the level and there's even more chance of getting stuck.

 

And of course its easy to say "check the level at the back gate" before leaving. If its full to overflowing or nearly full, great. If its 6" or maybe 9" off, you know the pound is down a little but you'll know your own boat and unless deep drafted, will know its okay to proceed. If its 2' down and you can see shopping trolleys, rocks etc on the puddle that was the next pound, if course you'd not go forwards. But what if its 10" down, and the pound you're entering is a short one, and so is the next one and the next one? Do you stay in the lock and precautionarily run water down, knowing that by doing so, you're probably committed to running water down for the next 3, 4, 5 or more locks too? Or proceed gingerly so as not to get stuck?

 

Basically its not a black and white issue but there's grey areas and a judgement is required.

[Tacet]

 

When the boat grounded, with its stern in the forebay, not only did it offer a near perfect plug to stop water entering the lock, but it offers a significant obstruction to water reaching the ground paddles.

 

Only once it starts to pitch forward does it offer room for water to reach the ground paddles.

 

The question is "are the ground paddles open to water passge before the boat reaches tipping point"

 

Not sure, but certainly worth drawing the ground paddles to find out, should the situation arise.

 

One of the more practical precautions to reduce the prospects of this type of catastrophe is to leave the ground paddles up until the boat has pass over the cill; it has to help, even if only a little.

[Tony Dunkley]

 

Not sure, but certainly worth drawing the ground paddles to find out, should the situation arise.

 

One of the more practical precautions to reduce the prospects of this type of catastrophe is to leave the ground paddles up until the boat has pass over the cill; it has to help, even if only a little.

 

It should not be a question of 'drawing ground paddles to find out', because if you're entering or leaving the top end of a lock with the pound significantly down then the paddles should be up any way.

In Post 116 I said " loaded boats get in and out of locks noticeably quicker with the top paddles up, allowing the displaced water better passage to run back out of or in to the lock chamber." . . . Believe it . . . it's not an opinion or a theory, it's a fact . . . something I was taught, a frightening number of years ago, and then proved in use to be a very handy and useful thing to know. Loaded boats had something around a foot, or more, draught than most pleasure boats, so a loaded boat entering or leaving a lock with a full pound had roughly the same sort clearance over the cill as a pleasure boat with quite a low pound. Suggestions on here that a boat's hull, if over the cill, will stop water running through ground paddle holes is just complete nonsense.

[Radiomariner]

If you do inadvertently cill the boat you really cannot afford to waste a single second dropping the lower gate paddles and opening the top paddles to raise the boat off the cill. It is obviously impossible to say you have X number of seconds because it depends on so many factors......

 

 

......

 

Slightly disagree. Drop lower paddles immediately, yes, but pause a short while to assess the situation before carefully opening the top paddles.

What a strange reply. I was told when I first hired a boat that somebody should constantly monitor the boat as the lock emptied and be prepared to abort the movement. I'm asking whether this incident could have been avoided had the crew shown more vigilance. Perhaps it couldn't have been, I'm just asking.

Experience and vigilance do not always come together. I would also consider adding "diligence" to the equation, lack of which happens to many of us when on holiday.

I hope James at Wyvern keeps photo's to show to hirers as a warning as to what can happen.

Edited September 30, 2014 by Radiomariner

[Tony Dunkley]

In the course of this thread it's occurred to me to ask if it is the normal practice among pleasure boaters to check the gates behind you for leakage whilst working, and especially just before leaving a lock. It was something always done without fail at every lock by professional boatmen, almost subconciously, it only needs a glance, as part of the process of working a lock, partly to reduce the chance of pounds dropping behind you and also to make sure that none of the paddles were partially fouled and hadn't gone right down, slowing the lock from filling or emptying as fast as possible.

 

Would anyone like to answer this?

[Radiomariner]

 

Would anyone like to answer this?

Those that believe in always leaving the bottom gate open certainly would not!

[Radiomariner]

Slightly . Unusual experience to be avoided. If C&RT (BW) tell you not to use the locks don't use them!

Happened about 28 years ago.

I was moored near the top of Hatton flight about 8am preparing to unmoor and go on down. A number of boats behind us were also preparing to go down. A BW man approached us and told us to wait until he gave us the OK. He told all the other boats also. The reason was that someone had left paddles open overnight and a pound had completely drained. The BW man and his cronies then proceeded down the flight slightly opening both top and bottom paddles all the way down the flight. After about 20 minutes a boat full of beer guzzling youngsters (yes at that time of the day) Passed us towards the locks. I told them not to go and why. They decided to ignore me. It took them ages to fill the lock because a bottom paddle was open, but they eventually sussed it out.

About an hour later we passed them in one of the pounds near the bottom. They were all out on the roof with their case of beer. They had sunk. BW man told me that the pound had drained with them in it. The boat had settled on the soft mud. As the pound level came up the boat remained fast in the mud until down flooding sunk it properly. A rare occurrence indeed but worth remembering if your boat ever sits on the bottom. I cant help but wonder how many cases of beer they had stowed on board!

Edited September 30, 2014 by Radiomariner

[bizzard]

See-saw cill balancing acts would become a thing of the past if your boats were fitted with my patented ''Centreboard type forward cill warner''.

[muddywaters]

It is very scary when you realise the boat is stuck whist emptying or filling a lock. I'm glad it turned out Ok in the end.

 

I wonder sometimes how much 'training' people get when they hire a boat these days. If you ensure there is one person manning each open paddle some of these incidents could be avoided but in practice it isn't always possible. I prefer to use just one paddle if I'm solo for this reason but then again it does slow things down. Also if you have a very leaky gate, shutting off the paddles might not help.

99.9% of my boating will be single handed so I fully intend to do this as well.

Okay it will take longer but a price worth paying for that little bit of extra safety.

And any other boats I might be holding up simple answer I'm solo so lend a hand, but there better be two of you because the second someone else is working the lock I'm back on the boat, the easiest way to avoid lock accidents