length/beam ratio of around 20

Quiet.

But it seems several posters are incapable of doing so. Clearly most comments are over their heads yet just moan and complain because they are unable to understand the replies. They wish to drag the forum down to their level in order to understand rather than except it is beyond them. They could try and read a book but nay...too impatient!!.... Yet when their failings are pointed out..become very aggressive and pugnacious and turn to polemics.

I don't understand the brain or brain surgery, doesn't mean i should assume others cannot nor ask them to dumb down a debate so much that even simple comprehension of words is being questioned!!

 

Your first word is applicable advice to yourself - or is English your second language?

 

Quote."These are made using NPL round bilge naval vessel hullforms, nothing like a modern catamaran," Quote.

I was Lock Crowthers business partner. When he was visiting the UK he spent time with the british navy at their testing facility. He was particularly interested in the design of their fastest destroyer hull designs. He used this information in the design of "Bagatelle", his very successful 52ft cruiser/racer, which cleaned up the opposition in East Coast racing in Aus.
I was the construction consultant in the building of Bagatelle , and can assure you that the bow bulbs, mid sections and tail "bustle", were all derived from the info Lockie got from the british navy.
Bagatelle was a "breakout" design, and formed the basis for Locks later "Catana" designs.

 

Yes, I do "accept" that advanced mathematics is beyond me, but as for getting some more basic insights into the nuts and bolts of the catamaran hull interference phenomenon, your contribution in terms of intelligible explanation rarely leaves the starting blocks, and, in my opinion, what was contained in post #33 was just a red herring that didn't help anyone, in fact the reverse. And if you are getting confused between "quiet" and "quite", just revert to "indeed" !

 

That is not a problem, or shouldn’t be. Since one can describe “something” with maths and then use words to describe what is occurring with the maths.

For example:

X^2 + y^2 + 2gx + 2fy + c = 0

Or one can say…the path of a point at a fixed distance from a fixed point.

Or more simply, a circle. But...do you know what a circle is??....as simple as it sounds...this is the whole point!

One does not always need to understand the maths to understand a concept, especially where words can replace the maths for a better more general understanding.

So in the absence of being able to understand the maths, words can be used, just as I did in post #33. And here is the point.

Many non-engineers or non-technical on this site constantly bleat on about …oh you engineers never think out of the box… and rubbish nonsense phrases like this. Well, here is a case in point.

Owing to your inability to understand the maths, you have substituted a wall of “understanding” at the level you can grasp or made for yourself to understand “something”. However, you are trapped by your own box and thus unable to think out of your own box – rich huh!. Your preconceived ideas of “something” (which are generally incorrect) are holding you back from understanding. Because when you read something that flies in the face of your “wall of understanding” you criticise and moan and bleat make it simple, yet do not even consider that your own “theories” and level of understanding is wrong.

Well, that described in #33 is simple if you read the words not focus on the details as your 4 walls are screaming at you to do. But you are unable to because it doesn’t equate inside your small box world you have created for yourself.

The very simple idea of taking a hull and making into 2 hulls…has gone over your head and several others on this thread. It is a simple thought/mind experiment to convey the maths. Can you grasp this….and it seems no, you cannot. But you’re at not alone in this it seems. (The most famous though/mind experiment is that of Schrodinger’s cat if you’re interested; all related to quantum physics. – lots of complex maths).

Since once you are able to grasp and understand the basic concept, further comments about shape you realise then also fall flat. Because shape plays little part, despite what your box wall is telling you, as has been demonstrated, even in the report/paper cited. But if one is unable to understand the basic concept, even using simple words, then clearly you won’t be able to understand the finer points such as shape, trends and length-displacement ratio.

So, all you are now doing is taking over threads with your “I don’t understand so your explanation must be wrong” time and time again – it’s tiresome. Thus just highlighting to everyone your ignorance on a subject and in ability to say fair enough, it is beyond me, and let others debate it.

And therein lies the rub. Relying on a computer (the same that many non-engineers/technical wish to do, for their work) to do my spell checking for me and then not checking it myself afterwards – too lazy. But do I care, nope. Since you clearly saw the error, yet fail to see your own errors!

 

Actually, Ad Hoc, your mistake was serendipitous and accurately revealing, because aside from your pathetic excuses, quiet is maybe something you should adhere to.
For some reason this analogy seems to fit: US scientific and mathematical technocrats (and self designated brilliant brains) devised electronic systems that assuredly would counter and blind SAM missiles aimed at B52s ... but 15 B52s were split into pieces and fell along with sheets of burning fuel filling the sky.

 

Lots of talk about boxes and walls in that diatribe, Ad Hoc, but I am still waiting to hear how a box-walled tunnel of a hull split along it's centreline leads to wave interaction between the two halves of the boat. Do enlighten me !

 

And as for a highly-paid professional man needing a spellchecker to write accurately in his native language, in commonly used words, give yourself an uppercut !

 

Quiet! Listen to the sound of one mind flapping!

 

Surprised Ad Hoc cites Schrodinger's cat as something I need to swot up on, getting very close to the religious mysticism he has decided that I peddle !

 

I can't comment on Crowthers influences, the Navy have used many different hull forms, but there are no bulb bows on the NPL round bilge series, and they have a flat, steeply rising floor into a radiused bilge, not a curved bottom. Below the waterline for much of the length they are not that dissimilar to an old tortured ply hull (more Unicorn than Tornado), but the large flare in the bow and deeply immersed transoms causes waves that would not be seen on a modern catamaran (or even on a Unicorn).

 

Mr Efficiency what have you bought to the table of knowledge, on this thread, merely a question. When it was answered albeitly in a way which you didn't understand, you simply shouted that you didn't understand. Surely most people would have gone away and done a bit of research using other sources, to try and better your knowledge or lack of it in this case. You can't simply expect academics and boffins to be able to simply expound their knowledge in a way lay men understand, it just doesn't happen in the real world.

This shouting and hollering on the internet forums to gather quick information is pretty common of the younger generations. May I, out of curiosity, politely ask your age. It is something that I find increasingly common with younger workmates, when it doesn't happen in the first round, they simply move on until they find something that does. My worry is that the knowedgible will not impart detail on the likes of this forum if they are harangued by those who are not willing to put the learning hours in.

I guess thats a philosophical argument so far removed from the original thread that we should simply get back to boat design.

 

Wayne, let me just say this, it is a good thing he became a naval architect, rather than a member of Her Majesty's Diplomatic Service. What do you think ?

 

waynemarlow, I will express my modest opinion, trying to refute what you say.
We could say that the participants of this forum belong to three categories (there may be more but let me set only three): those without technical knowledge, those that have and those who do not speak English. This simple classification leads, in my opinion, to think it is necessary to express our arguments in very simple terms because, otherwise, 95% of participants will not understand us properly.
If someone gets too high scientific level of their views, I sincerely believe that he is in the wrong forum. You can, of course, express your opinion, but has the danger that someone considers you littel pedagogical, bit pedantic and even offensive in some way. I do not think anyone needs this forum to enhance his professional standing, so it should not be necessary to raise the level. Many use the forum as entertainment, as query "normal" doubts and some to find customers. All that is admissible. Academic discussions or dissertations are for other more appropriate forums.
I believe, therefore, that a modest, clarifier, tone is very desirable. Otherwise undesirable. Disparaging who, for whatever reason, can not understand we, I do not find it interesting.
This is my opinion.

 

Seems to me Ad Hoc, no matter how much in the way of smarts he possesses about the subject matter, does not have the aptitude to teach, explain, or convey it to others, especially the dreaded laity, whom he clearly regards with contempt. Too bad about that.