On Wed, 28 Jan 2004 12:52:40 +1300, MC wrote:



felton wrote:

On Wed, 28 Jan 2004 09:43:05 +1300, MC wrote:



DSK wrote:


JAXAshby wrote:


dougie, a "benefit" is something that adds to the overall effect. In
this case
there is no benefit because there is no problem with transoms not
being strong
enough on the size and type sailboats under discussion. Calling it a
benefit
doesn't make it one.


Let's see... an inherently stronger structure is not better than an
inherently weaker one? What sort of engineering is this? Oh wait, it's
JAXINEERING!



A reverse transom is still lighter and faster than a canoe and is
designed to be strong enough. Your argument is ridiculous.

Cheers


"The canoe stern, besides being a thing of beauty, is according to
Crealock, "a potential bow; for when the weather is truly bad, it is
the stern which will bear most of its venom."


never seen a trasom crushed by a wave. I fully agree that if you cannot
keep sailing that a canoe offers some advanates for sea keeping with
drogues etc. but the strength is not the issue.

The canoe stern is hardly unique to Valiant.

It also follows very old design ideas.


The above quote from
Crealock was written relative to the PSC 37, also, coincidentally, in
the Sailboat Hall of Fame. Having a canoe stern doesn't seem to be
disqualifiying boats from the Hall of Fame


But none of them win races anymore -not even in the southern ocean
running before waves....


Cheers

But we weren't talking about optimal racing designs. We were
originally talking about seaworthy designs for challenging conditions,
at least I think we were.

From the Hall of Fame induction...


"The outsized appeal of the Valiant 40 once earned it the label of
"cult boat" in some circles, but that did a disservice to the fact
that much of the boat's popularity derives from its remarkable
achievements under sail. It has been the boat of choice for a number
of circumnavigators and has recorded finishes at the top of fleets in
some of the world's most challenging races, including the Singlehanded
Transatlantic and the BOC Challenge. In the Valiant 40 Resourceful in
l983, Mark Schrader set the record for the fastest circumnavigation,
becoming the first American to sail around the world via the five
capes.

Of all the bragging rights that go with Valiant 40 ownership, one of
the most impressive, according to Worstell, is that no Valiant 40 has
suffered a disabling failure. "Failure" is certainly not a word to use
in connection with this boat, whose success began with innovation and
continues with enduring excellence."

But none of them win races anymore -not even in the southern ocean
running before waves....



felton wrote:
But we weren't talking about optimal racing designs. We were
originally talking about seaworthy designs for challenging conditions,
at least I think we were.

And structural strength. That was the specific point I raised which MC
seems to have not grasped.

From the Hall of Fame induction...
.....
Of all the bragging rights that go with Valiant 40 ownership, one of
the most impressive, according to Worstell, is that no Valiant 40 has
suffered a disabling failure. "Failure" is certainly not a word to use
in connection with this boat, whose success began with innovation and
continues with enduring excellence."




MC wrote:
No think of this: A flat reverse transom is lighter because no material
is added beyond that associated with the aft section. Think of the
amount of curved material in a cnaoe stern that does not contribute to
hull performance!


And this has *what* to do with structural strength?

The issue at hand- all else being equal (which you can take to mean
framing, lay-up, and/or weight per square measure of hull surface)

... The nearly flat transom has to resist mostly
compression of the hull section but as you can see from sugar scoops and
cut aways that is not that large.

Most of the sugar scoops I see have some structural support. The radical
ones on racing boats are built out of hi-tech materials, which are
usually far far stronger anyway. In other words, using the same
materials, a canoe stern could be built lighter. That doesn't mean it
would be as fast of course, and that is why you don't see canoe sterns
on racing boats.


... Put another way, closing the transom
mostly stops waves boarding.

hmm, I thought you claimed to have at least some tiny eddication as a
naval architect? Now you are showing ignorance of basic physics. Closing
in a transom does not stop waves from boarding. Reserve bouyancy stops
waves from boarding.

A transom would only have any effect in stopping a wave from boarding
after the pitch rate had exceeded the reserve bouyancy.




.....Do you get it now -as for strength, have you seen a transom
crushed by waves -or does one design boats for ramming exercises?

No because usually they are built strong enough. But that does not prove
that, pound for pound of like material, a canoe stern is stronger. Which
is an inherently stronger shape, a triangle or a square? A pyramid or a box?



Hey, I'm not the one agreeing with Jax


But he he knew the answer to your question.

He didn't even understand the question. BTW you still haven't explained
your statements, or your own answer to the same question. Giving up?

BTW2 when are you going to pay me the money you owe on the bet you lost?

You ran away from explaining the capsize ratio, and here you are talking
about structural issues. Do you ever stick with a topic long enough to
actually learn anything?

Fresh Breezes- Doug King

And structural strength.

there is no structural strength problem, therefore there is no issue.

Reserve bouyancy stops
waves from boarding.

canoe sterns have less reserve bouyancy than transom, one of the bigger
complaints re canoe sterns

JAXAshby wrote:
(among other things)
canoe sterns have less reserve bouyancy than transom

Correct, Jax. Very good!

.... one of the bigger
complaints re canoe sterns

Uh-oh, you better talk it over with MC. He says that reserve bouyancy
isn't an issue because it's the transom that keeps out big scary waves.

DSK

He says that reserve bouyancy
isn't an issue because it's the transom that keeps out big scary waves.

the reserve bouyancy of a transom is one of the reasons a transom is prefered
over a canoe stern.

dougies, it was you who were disagreeing. And now you are agreeing. If we
wait a couple hours will you be disagreeing again?

(among other things)
canoe sterns have less reserve bouyancy than transom

Correct, Jax. Very good!

DSK wrote:



You ran away from explaining the capsize ratio,

On the contrary I explained it in terms a mathematical layperson like
you should have been able to understand. Why do you live the big lie,
afraid of the truth? Now do you really want me to repost it so you won't
understand it again?

Cheers

You ran away from explaining the capsize ratio,

MC wrote:
On the contrary I explained it in terms a mathematical layperson like
you should have been able to understand. Why do you live the big lie,
afraid of the truth? Now do you really want me to repost it so you won't
understand it again?

Yes please do.

Also, be prepared to explain why _your_ explanation disagrees with the
explanation of the professional naval architects who devised this measure.

Fresh Breezes- Doug King

professional naval architects

often those who claim to be such, are none of the three. In most jurisdictions
there is no more legal definition of a "naval architect" than there is of "lead
crystal"

professional naval architects

JAXAshby wrote:
often those who claim to be such, are none of the three. In most jurisdictions
there is no more legal definition of a "naval architect" than there is of "lead
crystal"

Sure, Jax whatever you say. Instead of "professional naval architects" let's just
call them a group of people who just happen to make their living designing
sailboats, and consulting with builders of sailboats, and teach engineering and/or
naval architecture, and providing references for insurance companies about
sailboats, and other activities relating to sailboats & the sport of sailing, and
are paid money for all these activities.

Of course you're smarter than all of them Jax. It will upset them greatly that you
disagree. The fact that you don't know what causes tip vortex and can't figure out
what hull speed means is irrelevant.

But you can explain reserve bouyancy to your pal MC. He won't listen to me when I
explain it. BTW did you ever figure out where you can buy a cement slab for your
mobile home?

DSK