Sail Aerodynamics
 

OK you seem determined to make me rub you nose in your error but here it
is. You said and reaffimed that the equation was:

"
CSR==(Beam / Disp ) ^ 0.333
"

but it is really

Beam/(displacment)^0.333

Won't you agree that that's quite different? Now I tried to point it out
gently and even indicated that your parenthesis was in the wrong place
but you are the one who escaltes it again by not listening and thinking.

Sigh. Will you never learn?

Cheers


DSK wrote:

MC wrote:

You mean like pointing out the error in your last equation?


You mean like *claiming* to point out the error?

DSK

Sail Aerodynamics
 

OzOn wrote:

On Thu, 29 Jan 2004 22:41:16 GMT,
scribbled thusly:



Notice how everytime DSK posts an ad hominem attack on someone, he brushes it
off as "a fact".

Doug was such a poor, incompetent sailor that he gave up sailing and bought a
diesel trawler.


Hey Bill, I've been saving this for you.
It certainly suits
http://www.squirtsplace.com/wav/StupidPeople.wav


Now why say that? Are there no grains of truth in his post?

Cheers

Sail Aerodynamics... oops back to CSR
 

MC wrote:
OK you seem determined to make me rub you nose in your error but here it
is. You said and reaffimed that the equation was:

"
CSR==(Beam / Disp ) ^ 0.333
"

but it is really

Beam/(displacment)^0.333

The second equation is right. Was the whole divisor included in the
parenthesis in my first post? If so, that was an error.

However, we now know for sure that this is indeed what you're talking
about, and it has nothing to do with initial stability (as you
repeatedly said) and it used to compare relative LPOS for similar
vessels when no more detailed measurements are available.

I posted several links explaining what this measure is intended for,
including at least one article by one of the members of the panel that
created it. But what does he know, he's a "professional naval
architect." I can post them again, just to show how ridiculously wrong
you have been about it all along.

Now, are you interested in backing up and restating all your bushwa
about your great credentials as a naval architect, and what CSR means?

You can back up even further, and post the details of this boat you
claim won our bet.

But I don't think you will. And I don't think you're going to email any
US sailing officials any more than you ever emailed Phil Bolger. You
have no more to contribute to this forum on sailing topics than Boobsie.

DSK

Sail Aerodynamics... oops back to CSR
 

DSK wrote:

MC wrote:

OK you seem determined to make me rub you nose in your error but here
it is. You said and reaffimed that the equation was:

"
CSR==(Beam / Disp ) ^ 0.333
"

but it is really

Beam/(displacment)^0.333


The second equation is right. Was the whole divisor included in the
parenthesis in my first post? If so, that was an error.

At last.


However, we now know for sure that this is indeed what you're talking
about, and it has nothing to do with initial stability (as you
repeatedly said) and it used to compare relative LPOS for similar
vessels when no more detailed measurements are available.

OK let me try to get you to see something else. If the beam of typical
vessels is the same inverted or the right way up would the capsise
screen be different?

Do you not agree that the underlying assumption of the screen is that
the inverted water plane width is directly proportional to the beam?

Now if you've got that, isn't the non-inverted water plane width also
likely to be directly proportional to the beam?

If that's so, could there be a connection between initial stability and
inverted stability as valid as the CSR formula itself?

Finally, the metacentric radius (BM) is the height of the metacenter
above the center of bouyancy. Clearly this is a very important figure
for initial stability as it determines the righting lever (If I remember
this is called Attwoods formula). Now BM can be shown to be the moment
of inertia of the water plane about an axis through the C of G divided
by the volume of displacement. The mathematical connection to the CSR
formula arises directly from the moment of an immersed wedge being
1/3y^3 theta where theta is the heel and y the waterline beam (of the
immersed wedge). The extension of this is exploited by Barnes method for
stability calculation -which you may know about.

OK?

Cheers

Sail Aerodynamics
 

I doubt that would help that much.

Oz wrote in message ...
On Fri, 30 Jan 2004 02:36:34 GMT,
scribbled thusly:

Clearly DSK cannot defend himself. He needs assistance from other,
similar
losers.

BB

Jeez Bill, the only help he'd need to defend himself from you is from
a translator.....to turn what he says into gibberish so you'd
understand it.


Oz1...of the 3 twins.

I welcome you to crackerbox palace,We've been expecting you.

Sail Aerodynamics... oops back to CSR
 

Does it matter if this is from the real MC/Navvie

Navvie wrote:
OK let me try to get you to see something else. If the beam of typical
vessels is the same inverted or the right way up would the capsise
screen be different?

Hello? The CSR is a metric for the boat. If the boat is upside down,
it's the same. If the boat is standing on it's bow, CSR is the same. If
the boat has been propped up on jackstands for years, CSR is the same.

Seems a rather easy principle to grasp, there.


Do you not agree that the underlying assumption of the screen is that
the inverted water plane width is directly proportional to the beam?

Now if you've got that, isn't the non-inverted water plane width also
likely to be directly proportional to the beam?

You're trying to get fancy, aren't you? Why not work with simple
principles first, instead of leaping off the deep end.

1- the inverted waterline section of any given could be very very
different than the normal waterline section. Usually boats are double
ended at the water line, but very often they have wide transoms.

2- volume distribution is just (or more) important. A high sheer & and a
canoe stern will force the boat, when inverted, to try and float on two
points. Obviously this will affect it's inverted stability but not it's
normal stability.

3- CSR takes none of this into account



If that's so, could there be a connection between initial stability and
inverted stability as valid as the CSR formula itself?

Looking at what I've said above, WTF do you think?


Finally, the metacentric radius (BM)

Your whole argument is a lot of BM.

But to get serious for a moment... CSR is of some value comparing
vessels of similar size & form. It is simple & quick. It is not a
substitute for formal LPOS calculations, but there may not be data on
some boats to do this. Therein lies it's merit.

In addition, the LPOS (Limit of Positive Stability) figure has a lot of
weaknesses. It takes no account of sheer, as I mentioned above, and
deliberately does not account for deck camber or cabin trunk volume. And
it does not take any account of athwartship rotational inertia (or X-mmi
if you like jargon) which is a very large factor in how likely a given
boat is to be rolled over, or to stay inverted.

In short, I don't see any benefit in continuing this discussion with
Navvie nor any sock puppet... although thanks for the gibberish, whoever
you are, it was a brief laugh and slightly brightened my morning. Maybe
later.

Fresh Breezes- Doug King
(on line since 1989 and still 100% sock-puppet-free)

Sail Aerodynamics
 

"JAXAshby" wrote in message
...
read it again, dougie. And again, if need be. And again. And again. And
again ...


Jax, only MC can make sense of your posts by reading them a second time.

The rest of us just get a headache.


Regards


Donal
--

Sail Aerodynamics
 

"JAXAshby" wrote in message
...


dougies, I have repeatedly suggested you read a book by someone who knows.



You've written a definitive book about this, too???


Twit.


Regards


Donal
--

Sail Aerodynamics
 

are you suggesting that none of you but mc has anything approaching a 3 digit
IQ?


read it again, dougie. And again, if need be. And again. And again. And
again ...


Jax, only MC can make sense of your posts by reading them a second time.

The rest of us just get a headache.


Regards


Donal
--

Sail Aerodynamics
 

"JAXAshby" wrote in message
...
are you suggesting that none of you but mc has anything approaching a 3
digit
IQ?

No, quite the reverse, in fact!

Are you suggesting that you have a three digit IQ?



Regards


Donal
--