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IanD

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Everything posted by IanD

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  4. That's fine, you do that, it's your choice, none of this new-fangled rudder rubbish for @bizzard, hurrah!!! 🙂 (though IIRC the patent's about 60 years old, so it's not exactly "new"-anything...) But please don't assume the Schilling *doesn't* work with no power, it's just a bit less effective than a big flat plate because it's shorter -- I've used it with no power and it steers OK, but you need a bit more rudder angle than a big flat plate. On the other hand it carries on working over to much bigger angles than a flat plate, so I expect it can move the boat just as well, but with a bigger difference in the required rudder movement between power on and off -- so the feel takes a bit of getting used to, like having a rudder that carries on working well past "normal" angles does.
  5. You don't *lose* steering, it's just a bit less effective than a big flat plate rudder. The rest of the time (99.99%) it's more effective.
  6. You can but it doesn't show the improvement it does with the prop pushing water over it -- Ricky did comment on this, there's not much steerage way with no power on. TBH this is a price I'm willing to pay for better steering with power on -- since I very rarely if ever try to steer a boat with power off (I can "glide" in silence with power on...), I don't really care about this... 😉 That's just a low profile aerofoil-type rudder (NACA010?) optimised for higher-speed low-drag hulls with low rudder angles, because this is where most rudder research is targeted. For low speed and high angle applications like a narrowboat you really want a thicker profile with a blunt nose to stop the wake breaking away at large angles; the Schilling fishtail then increases lift and maximum working angle further. There is some increase in rudder drag but this is completely negligible at low speeds and compared to narrowboat hull drag and narrow/shallow water drag. The drawing I started from came from Schilling's later patent and was specifically designed for lower-speed applications where good thrust at high rudder angles is desired -- it's designed to work up to 75 degrees angle, and I can confirm that it does this. It takes a bit of getting use to because it's ingrained into most boaters minds that there's no point pushing a rudder past about 45 degrees because it doesn't really do anything, but once you realise that pushing it over even further works rather well the difference is pretty obvious. I found with it right over you could push the stern directly away from a mooring at right angle to the bank without moving forwards at all, just like a stern thruster (according to Ricky) but a lot simpler and cheaper 😉 Combined with the variable-speed BT I've found I can just move the boat sideways ("crabbing?) with no fore/aft movement, like it's being pushed by an invisible hand... 🙂 It's a standard thin aerofoil rudder, designed for good lift/drag ratio in higher-speed ships.
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  8. I've got one on my boat (new-build from Tim Tyler/Finesse) and I'm very happy with it -- it gives light responsive steering and excellent manoeuvrability up to much larger working angles than a flat plate rudder, when pushed right over to 75 degrees or so the prop wash comes out sideways with no forward thrust at all, it behaves more like a stern thruster. Not just my biased opinion, Ricky at Finesse confirmed this compared to otherwise identical boats he's built. In my case there was a second reason for choosing it, which is that it's shorter and sticks out less beyond the stern than a bigger (and less effective) flat-plate rudder -- it's about 200mm shorter front-to back (500mm vs 700mm) and sticks out about 200mm less as a result (only about 200mm past the stern) so I can use a short button fender. This matters on a 60' boat which was designed to go through the short Calder and Hebble locks which are "officially" only 57'6" long, but where you can squeeze a 60' boat through "with care" -- I managed to get through the shortest one without even lifting the fender or having any contact between rudder and bottom gate. I don't know what it would cost to have one made up but IIRC it added about £1000 (inc. VAT) to the cost of mine, considerably more effort to build (multiple plates and a *lot* of welding and grinding) but this is instead of a flat plate rudder so presumably some saving by not building this. Maybe getting a replacement one made would cost more than this? Here's a photo of it, and a drawing in case you want to get one built... 🙂 (the small red peg is a stop to prevent it swinging all the way round into the prop when going astern, and the little side steps on the bare hull were later removed because the rudder is a better step for getting out of the water...)
  9. I don't think it's to do with going slow or fast, it's not realising two things -- one is that most boats are trimmed down at the stern, so if you hit an obstacle or go aground anywhere along the boat while going ahead pushing forward makes the problem worse, the second is that whacking on more power sucks water out from under the boats and makes the stern squat down which makes the problem worse still. I've helped several boats who've gone aground over the years where no amount of full-throttle thrashing has get them off, but a pull backwards from another boat worked. If just a pull isn't enough then a snatch (starting with a slack rope) can work, but you need to be careful because this can cause *big* tensions in the rope and either snap the rope (I've seen this) or even pull the T-stud off (other people have seen this) -- so make sure to use a nice stretchy rope like nylon, and not too short so there's enough "spring" in it. Alternatively run some water down to raise the water level a bit, though this isn't so helpful in a pound half-a-mile long... 😞
  10. IanD

    Lemons

    Not just not enough gravy, what they often pass off as "onion gravy" (e.g. with sausage and mash) is a pale imitation of the real thing -- for which you need *at least* one big onion per person (better still, two) plus lots of time to caramelise them properly, and some good stock, and a damn good glug of madeira/marsala/port... 🙂 Utterly glorious but too much time and effort for most restaurants to bother doing properly... 😞
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  12. Which is exactly what I said, and do -- as I said, if not for being pre-warned by posts on CWDF I might well have been the second boat sunk there, two weeks after the first one... 😞
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  14. Home of the Tipton Slasher IIRC... 😉 (friendly and nice beer too, last time we were there)
  15. My point was that -- at least, before the Diggle sinking, which I think was a previously undiscovered way of sinking in a lock -- if the water level is low (not dry!) the usual approach would be to try and get to the next lock regardless, because this very often works without running water down, and was not thought to be very risky. Like many other boaters I've done this plenty of times with the water anything up to a foot (or even more...) down with no big problem, if you're grinding on the bottom *then* go and run some water down -- if you do this every time the levels look a bit low (as some posts seem to be suggesting) you'll spend most of your time on canals like the HNC running water down for no good purpose. After Diggle, if the water is low when a lock makes the level (thanks @Tam & Di ) going up I always go and check below the bottom gate to see if it's leaky -- because just looking at the level at the bottom gate or brickwork doesn't tell you whether there might be a problem or not. At least, on narrow canals like the HNC -- on broad ones like the Rochdale this much leakage makes the problem obvious because it takes five people to open the gate... 😉
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  17. No problem, always happy to accept (or give) an apology 🙂 If it's a pole antenna and you've cut the tube down already then very likely you won't have any problem. Mind you, if you'd given this information at the start we could have saved a lot of typing and apologies... 😉
  18. <sigh> most reasonably people would say a lock is full when the water level inside is the same as the upper pound outside and you can open the gate -- which is of course what I meant... 😉 So I'll ask again -- if you look at the bottom gate and see the water level is low when you open the top gates, what would you do about it?
  19. Apart from stating the blindingly obvious -- what do you do then? Insist on going ahead every single time the upper pound level is a bit low and running water down through the next lock, and repeating this at every lock in the flight due to knock-on effect, possibly making the problem worse, and meanwhile holding up any other boats? What if the next pound is half a mile long? If you've ever travelled on the HNC I'd have thought that you'd know that low pounds are *very* common, and in most cases not worth doing anything about so long as you can get through OK... 😉
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  21. Huh? Pound above lock is low, so water inside lock is at the same level (low) when it's full -- no amount of looking at the gates will raise it any further. Usually if you think the upper pound is deep enough to get out of the lock and up to the next lock, you won't go ahead and run a lot of water down and possibly pass the problem on to the next lock just because the level looks low. And if you're wrong then you swear and go and do it and wait for the pound to come up, but there isn't a big risk of the boat sinking in the lock. Unless the bottom gates are *extremely* leaky, which they were in this case... 😞
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  23. I think that was a way to sink a boat that pretty much *nobody* saw coming *before* it happened (it's easy to see *after* it happened, hindsight always helps...), and where the normal solution to a low upper pound (running water down into the low pound above) wouldn't have worked because the water inside the lock was dropping faster then it could refill past the obstruction formed by the boat. CART later put a red board and warning sign on the lock telling boaters not to try and leave if the water level was too low, but we went through only a couple of weeks after the sinking. It was some time before they fixed the horrendous bottom gate leaks that were the root cause... 😞
  24. IanD

    Lemons

    Ooh, I do like big jugs, SWMBO has two... 😉 (in the kitchen -- they hold *loads* of gravy...)
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