Chris_marigold

Cant On a narrowboat, a raised outer section of a deck normally to the fore and counter decks. See here. I wasn't there and with all such accounts it's hard to be able to give exact timings. But I think it's pretty obvious that the existence of a ledge near to the bottom gate almost exactly designed to catch the modern narrow boat (it was I think less than 2 years old) is pretty disastrous. Also this is significantly worse than catching the stern on the cill because of the very low freeeboard of the "cant" and the use of floatable floorboards over the engine. It's also trickier than catching the prow in the bottom gate, which will after all be very obvious to the person winding the sluice. Beyond that I wouldn't like to say more than imo it only took a fall of 2 feet (in a 9'4" fall lock) to start the process off. Chris

Yes and thinking about it, the critical point on a slipway is going to be similar to a boat being held up at one end if the support under the boat extends to the end. In practice the supports (which are the rotation point) probably wouldn't extend past the three-quarter point. But what is the maximum gradient for slipways? Googling a bit, I see that the small boat slipway at Bristol Harbour has a 1:6 gradient (limit 6m boats) and I'd guess that's not dissimilar to those on the Thames. However the slipway for canal boats at Church Minshull is described as "difficult" and it has a 1:20 gradient. So presumably most slips designed for narrowboats are flatter. 4 foot on a 60' boat is 1:15. So if 1:20 is "difficult", 1:15 could be too steep for a narrowboat even without the support being near the end. But in this case the ledge was probably 6' - 8' from the end and I'd guess closer than occurs on a trailer. There are too many unknowns to go further, but it seems to me that a two foot drop would be critical for many boats even if some boats could go down further and survive.

Yes agree on the sin: it makes one-hundredth of an inch difference And you're right on the angle of the boat: when the stern is 2 feet below, the angle will be 4 degrees because the centre of the boat will stay the same with respect to the water level. Where it pivots is purely dependent on the balance of the boat and I don't think it would make much difference. But if you think about how much the water level has to drop to cause that, it's still only 2 feet. That's a quarter of the total fall of many locks and it can happen mighty quick. And 4 degrees still isn't much to detect by eye. Ok, a 4' difference between stem and stern is more pronounced but remember all the things that are usually happening at the time and from some angles it may not be so obvious.

Ok, smart alec. You have a 5 year old child. At every lock you tell her to get out of the boat and stand quietly on the bank while you busy yourself with the lock. Oh, yes, you tie her to a bench to make sure she doesn't fall in or wander off with a stranger or... If I was doing a risk assessment, I know which option would come out worse. Oh, and that happened to be one of the requests that Ken made for a sign at this particular lock and CRT refused to agree to it.

It's your maths that needs a little brushing up! Where did you get that formula from? atan(2/60) = 1.90915 Anyway I allowed myself 100% error, so it makes little difference.

No, it's a very similar issue from that point of view. Except that with cilling it's the prow of the boat that's dipping in the water and that is probably more resistant to being dunked than the stern. Remember that in this case the ledge was within a few feet of the bottom gate so it was caught close to the prow.

2 degrees on a 60' boat corresponds to 2 feet. Now I haven't worked out all the hydrostatics and it may be the front of the boat needs to be lifted twice that, but I'm assuming that the back of the boat will go down by about the same amount. The freeboard at the stern is maybe 18". So it only takes a little for the water to start pouring into the engine compartment, which is not waterproof in the typical narrowboat. Once the water starts pouring in it adds to the moment that is tipping the boat over and it will soon be unstoppable even if the water level doesn't go down any more. So you first have to close the bottom sluices and then go to the other end of the lock to open the top gates to start correcting the water level. That takes quite a few seconds or probably rather more than a minute. In this accident there was a complicating factor of a young girl in the cabin (with the front door locked). By the time Ken's wife had gone in to fetch her and try to get her out of the back door it was impassible due to the water. If Ken hadn't had the presence of mind to leave the winding, smash the side window and get them out they would both have been drowned. I think that is the reality with most narrowboats today. Chris

Another thing which I don't think has been mentioned is the way modern narrowboats are constructed. They're basically welded out of flat plates of steel with sharp corners that catch very easily on any protrusion. And the design is such a boat has only to be tipping a couple of degrees for it to start flooding aft and then sinking can happen very suddenly. The last time I went up Bank Newton (I've never been down) I was in my Dutch barge which is just the opposite. Apart from the rubbing strake and similar protrusions it has nothing that would catch. And you could probably tip it 10 degrees before it would start flooding. Is there any way to force manufacturers to go back to the older designs with rounded corners? Obviously it costs a bit more but it's a lot cheaper than reconstructing hundreds of locks. Chris

That wasn't my point. I think I can count 3 lawyers among my liveaboard friends - one of them is (was) a barrister. But they weren't the bolshy ones! Chris

In my experience bolshie boaters are quite capable of emptying a full elsan over your boat when they're annoyed but most of them couldn't run a successful lawsuit.

You may be right, but look where it leads. In this case they spent half a million, nearly all in legal fees - the damages were a fraction of that. I don't believe that if boating people saw that CRT was doing their level best to correct problems on these vintage waterways and being open and honest with people, then it would lead to a spate of litigation. But when they lie and deny and cover up it puts people's backs up, quite rightly. Chris

Can you fix a 6" layback with a saw? How long before another ledge appears? The top of the wall needs rebuilding. It wouldn't seem to need more than a few days by a decent stone-mason unless the real problem is the whole wall is bulging and the top is the true position. But for me the underlying problem is an institutional one. The legal department of the trust hadn't moved on since the days of BW which is what most of my canal experience is based on. Their instinct is first to deny; second to prevent others knowing about settlements that were made and third to prevent spreading alarm due to putting up warning notices. I gather the principals have now retired. I sincerely hope they are being replaced by people with a totally different mentality. But lawyers are a conservative bunch. Chris

If you want to see a picture of the wall, here it is. I think it speaks for itself. It's exactly at the height that a narrowboat will catch on when the water level is high enough: That photo was taken after the "scar" caused by the sinking had healed. This picture shows it soon afterwards: And here is the boat after they drained the lock, showing the boat was parallel to the lock and nowhere near the gate or cill: Chris