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Post by TonyDunkley on Aug 24, 2021 6:28:20 GMT
Mr Bernoulli and his effect. Which is just another example of conservation of energy. As first proposed by Emilie du Chatelet. Who was a girl by the way. 1706 - 1749. Sorry dunkers, you were beaten to it by a French girlie and 200 years! I remember Bernoulli's Theorem being covered in final year O-level Physics at school, and recognizing it as something I'd already begun to learn about some years earlier from a number of river and canal boatmen - some working for British Waterways, some for other carriers - who had been kind and indulgent enough to allow an inquisitive young lad aboard their boats, . . and to begin the process of educating him in how to steer and handle them. Their explanations for the rise or fall in water levels ahead, alongside and astern of boats underway in a narrow restricted channel -- and the effects on how the boat handled and steered -- were very different from anything to be found in school text books. They were expressed simply and practically, but for all that, were perfectly valid and did cover every aspect of how Bernoulli's 'effect' directly affected the behaviour and handling, including 'squat', of narrowboats and barges - powered or dumb - through bridgeholes, round bights or turns, or in confined or shallow channels in general.
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Post by Telemachus on Aug 24, 2021 6:52:49 GMT
Mr Bernoulli and his effect. Which is just another example of conservation of energy. As first proposed by Emilie du Chatelet. Who was a girl by the way. 1706 - 1749. Sorry dunkers, you were beaten to it by a French girlie and 200 years! I remember Bernoulli's Theorem being covered in final year O-level Physics at school, and recognizing it as something I'd already begun to learn about some years earlier from a number of river and canal boatmen - some working for British Waterways, some for other carriers - who had been kind and indulgent enough to allow an inquisitive young lad aboard their boats, . . and to begin the process of educating him in how to steer and handle them. Their explanations for the rise or fall in water levels ahead, alongside and astern of boats underway in a narrow restricted channel -- and the effects on how the boat handled and steered -- were very different from anything to be found in school text books. They were expressed simply and practically, but for all that, were perfectly valid and did cover every aspect of how Bernoulli's 'effect' directly affected the behaviour and handling, including 'squat', of narrowboats and barges - powered or dumb - through bridgeholes, round bights or turns, or in confined or shallow channels in general. … and of course why a boat ascending in a narrow lock tends tends to get sucked forwards strongly, counter intuitively since the water is coming in at the front and at first sight one would expect the boat to be pushed backwards (certain BCN locks excepted).
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Post by Deleted on Aug 24, 2021 7:28:05 GMT
It's almost impossible not to 'discover' these effects for oneself over time, if you're even slightly observant ... it's not that complex ... certainly easier than flying Which can catch you out as you say when suddenly the usual process doesn't work. Bascote staircase is another example where, the general principal of opening the paddle on the same side of a single narrow boat in a broad lock ( pinning the boat to the lock wall ) suddenly doesn't work Rog
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Post by TonyDunkley on Aug 24, 2021 7:28:33 GMT
As I understand 'bank effect', is it if you go slowly enough the water you push to the bank returns and holds you away from it. If you go too fast, you hit the bank before the returning water can repel you. Seriously, surely it's a name that someone has conjured up to explain what an experienced boater knows instinctively without bothering to add to the mystical vocabulary that seems to have evolved around canals and rivers. No, . . you've got that arse about face. The influence, or strength, of bank effect is directly proportional to speed, . . not inversely proportional. The boat, whatever size or type, has to be carrying enough way to push a 'flush' - noticeable rise in water level - ahead of it, and to create a noticeable drop in water levels - a 'draw' - alongsides. As for 'bank effect' being terminology for what your 'experienced boater' may think they know 'instinctively', . . I first heard the term used by Manchester Ship Canal pilots and tug skippers back in the early 1960's, . . and most recently in connection with that Evergreen container ship that got itself 'stemmed up' - to use a bit of commercial narrowboating terminology - across the Suez canal a few weeks ago.
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Post by brummieboy on Aug 24, 2021 7:59:25 GMT
Let's just think about levers. Give me a moment to think about that.
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Post by TonyDunkley on Aug 24, 2021 8:11:27 GMT
It's almost impossible not to 'discover' these effects for oneself over time, if you're even slightly observant ... it's not that complex ... certainly easier than flying Rog Going by the photo you posted earlier it appears that your "professional boat mover" hasn't 'discovered' very much, . . and nor is he likely to for as long as he persists in approaching bridgeholes way off the correct line, and depriving himself of the benefit of any helpful bank effect by reducing speed to a point where he could be outpaced by a ruptured duck ! The bad news for you is that the remark on the subject of how hydrodynamics in general affects boats in confined in narrow shallow channels is "not that complex" only serves to underline just how little you've managed to 'discover' for yourself.
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Post by Deleted on Aug 24, 2021 8:13:07 GMT
Rog, Did you discover that if you pay your licence fee and get a boat safety every four years, you get to keep your boat?
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Post by Deleted on Aug 24, 2021 8:13:09 GMT
Oh god take me now !
Rog
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Post by Deleted on Aug 24, 2021 8:13:41 GMT
Rog, Did you discover that if you pay your licence fee and get a boat safety every four years, you get to keep your boat?
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Post by Telemachus on Aug 24, 2021 8:32:22 GMT
He did some time ago, and you are in hell. It’s just that you haven’t noticed yet.
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Post by Deleted on Aug 24, 2021 8:34:43 GMT
Ah that explains everything ... I thought it was a case of 'those whom the gods wish to destroy ...'
Rog
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Post by kris on Aug 24, 2021 14:20:17 GMT
He did some time ago, and you are in hell. It’s just that you haven’t noticed yet. Just imagine a whole eternity of Dunkley’s drone.
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Post by JohnV on Aug 24, 2021 16:58:12 GMT
Nah !!! Hell would be not being able to put the Fox on ignore
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Post by TonyDunkley on Aug 24, 2021 18:25:51 GMT
He did some time ago, and you are in hell. It’s just that you haven’t noticed yet. Just imagine a whole eternity of Dunkley’s drone. As you're so underwhelmed by my input, why don't you provide some more interesting stuff of your own ? You could start by explaining how your inability to learn from the constant repetition of the same mistakes always led to the river current at Barton causing you to crash A41 into "Halcyon Daze" every time you tied up alongside. Perhaps you can pass on some of your vast experience and know-how to everyone else to whom the way their boats handle and behave underway, in river or canal, remains as much of a mystery as it obviously does to you.
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Post by Trina on Aug 24, 2021 21:22:05 GMT
He did some time ago, and you are in hell. It’s just that you haven’t noticed yet. Just imagine a whole eternity of Dunkley’s drone. 😱😱😱😱😱😱😱😱😱😱😱😱😱😱😱😱😱😱😱😱😱
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