IACC Boat speed at 30 degrees heel?
 

What did you expect them to do, switch on a pump or something?

Cheers

Scott Vernon wrote:

You didn't see the humour in a multi million dollar boat, with a multi
million dollar crew backed by a multi million dollar syndicate being bailed
with a plastic bucket?

SV


"Nav" wrote in message
...

I see. I expected more from you.

Cheers

Scott Vernon wrote:


sad? I thought it was funny.

SV

"Nav" wrote in message
...


It was very sad indeed. To have banked their defense so heavily on
lighter winds was not a good call.

Cheers

Scott Vernon wrote:



he he, I still chuckle at the picture of them bailing out the boat with
their cedar bucket.
;)

Scotty


"Thom Stewart" wrote in message
...



Nav,

Really!! You're not being fair calling those "Solo around the world"
boats mono's. Their beams are so wide and their draft so shallow that
they are Cats built in one piece and designed to sail with more than
half the hull flying.

They were just about as bad as the Kiwi POS used for the cup defense.

Their failure rate in that last so called race wound up being for
survival and not for speed!

Ole Thom

IACC Boat speed at 30 degrees heel?
 

design a decent boat.

"Nav" wrote ...
What did you expect them to do?

IACC Boat speed at 30 degrees heel?
 

Nav
scribbled thusly:
It was very sad indeed. To have banked their defense so heavily on
lighter winds was not a good call.



Oz wrote:
Actually I think it was a case of lack of testing.

Well, Team NZ said all along in the build-up to the match, that they had
invested more heavily in design and did not have the resources to spend
on on-water tuning. If they had increased their actual sailing time by
maybe 50% they would have had much more chance. It was a question of
having priorities in the wrong place.

BTW I wonder what figure is, dollars per hour, for sailing one of these
boats... not including initial design & building costs. I'm sure that in
heavier winds it gets more expensive, too.

FWIW I don't think Jochen Schumann got nearly enough credit for managing
Alinghi to their win. He is one of the greatest sailor of this
generation IMHO

Fresh Breezes- Doug King

Herreshoff Pic... & more heel
 

Nav wrote:
You really think that boat (?668) is beating to windward?

It looks like they are attempting to. Do you think they are heeled too
much for best VMG?


... Is 45 close to
30 when discussing trim and heeling?

IIRC at one point you said "30 to 40 degrees of heel" in relation to
being 'powered up' which you never could define.

In any event, 45 is a lot closer to 30 than it is to 20

DSK

Herreshoff Pic... & more heel
 

DSK wrote:

Nav wrote:

You really think that boat (?668) is beating to windward?


It looks like they are attempting to. Do you think they are heeled too
much for best VMG?



Please tell us about your sailing ideas where a spinnaker is carried as
a beating sail.


... Is 45 close to 30 when discussing trim and heeling?


IIRC at one point you said "30 to 40 degrees of heel" in relation to
being 'powered up' which you never could define.

No, I never said 30 to 40 degrees. It's your exaggeration coming in
again. I said IACC are powered up at 30.



In any event, 45 is a lot closer to 30 than it is to 20


Now you've gone from 30 to 40 to 45! Anyway you are wrong again. Wind
pressure (and therefore potential power extractionon) on the sail must
proprotional to the sine of the heel while leeway will rise roughly with
the cosine. OK?

The consequence of this is that keel boat speed will rise as wind
pressure on the sail rises but VMG will not continue to rise so fast and
will eventually fall due to leeway taking away from the windward
progress. Due to the shape of sines and cosines (I hope you know this)
the sine initailly rises more quickly than the cosine falls. Thus VMG
goes up monotonically with heel until sine and cosine functions have
opposite effects on VMG. At this point, the boat is sailing fast and
fastest to windward and to use my parlance it is fully powered up. A bit
more heel may well give more speed but VMG falls -and falls
progressively faster with more heel. That's why we have accurate VMG
instruments on board (but dinghy sailors have to guess their VMG which
is hard). From that design angle, VMG falls more and more quickly. The
designer picks a point to work on (typically 30 degrees as I said) to
decide freeboard. Thus at 45 dgrees heel VMG is probably well down and
the rails are going under (drag). This is not the same as when going
from 20 to 30 degrees heel. At ~30 the VMG for an IACC is highest, as I
said and this was also true for the classic 6m type Gimcrack whose very
accurate figures I gave you. Perhaps you should try to read Dr. Curry's
book 'Yacht Racing' (if you can find a copy) for qualitative discourse
on the effects of heel on real yachts? Now, It is possible to shape a
hull to have even more power at 30 degrees heel but the reason why this
is not done is that 30 degrees is also considered to be a human limit
for working comfort. If you had sailed offshore you would know that
heeling beyond 30 for any period is very hard on the body. I suggest the
current Beneteaus were designed to have lower human design angles for
the market they are aimed at -the charter/fun boat market. Mure purist
cruiser/racers (like Ella) take higher heel to reach peak VMG and also
carry full sail to higher windspeeds. Don't forget Ella was designed for
the roaring 40's -not the Med.

OK?

Cheers

IACC Boat speed at 30 degrees heel?
 

DSK wrote:



FWIW I don't think Jochen Schumann got nearly enough credit for managing
Alinghi to their win. He is one of the greatest sailor of this
generation IMHO


Can you explain why he wasn't helming -if he's that good?

Cheers

Herreshoff Pic... & more heel
 

Nav wrote:

Please tell us about your sailing ideas where a spinnaker is carried as
a beating sail.

I thought you were talking about the Valsheda pic.


In any event, 45 is a lot closer to 30 than it is to 20


..... Wind
pressure (and therefore potential power extractionon) on the sail must
proprotional to the sine of the heel while leeway will rise roughly with
the cosine. OK?

It seems to me that before you start to yabble about trig & calculus, you
should learn some basic math. 45 is definitely a lot closer to 30 than it is
to 20. Look it up.

In any event, your posts have become a morass of insults and double talk.
There is no basic fact so obvious that you won't deny it to try and "prove"
that I am wrong. It's predictable and boring. If you are going to be a
caricature, you should at least try & be funny!

DSK

Herreshoff Pic... & more heel
 

DSK wrote:

Nav wrote:


Please tell us about your sailing ideas where a spinnaker is carried as
a beating sail.


I thought you were talking about the Valsheda pic.


Well I even gave the sail number to make sure we were talking about the
same pic! Was that too hard for you to read?

In any event, 45 is a lot closer to 30 than it is to 20


..... Wind
pressure (and therefore potential power extractionon) on the sail must
proprotional to the sine of the heel while leeway will rise roughly with
the cosine. OK?


It seems to me that before you start to yabble about trig & calculus, you
should learn some basic math. 45 is definitely a lot closer to 30 than it is
to 20. Look it up.

Oh, now I can see the level of your maths ability. So you are not
interested in the behaviour of the boat but just want to say that 15 is
less than 25? If you had told me I was going to be talking to someone
with the maths ability of an 8 year old I would not have bothered
posting a detailed discussion on the basis of the relationship between
heel and VMG. If this is the case, then I apologise for posting
something so far above your education level that you think it double talk.


In any event, your posts have become a morass of insults and double talk.

Maths is is not double talk. It's precise and accurate and as for
insults, it's you that always starts it e.g. your last post.

There is no basic fact so obvious that you won't deny it to try and "prove"
that I am wrong. It's predictable and boring. If you are going to be a
caricature, you should at least try & be funny!


I though you claimed to be interesting in learning about sailing. I can
only surmise that this a lie because when I try to clarify your
misconceptions you become insulting and simply ignore what is said. Even
worse you then change what was said to suit your peculiar form of troll.
Why not try to engange your brain and think about what I wrote? I'd
enhjoy an intelligent conversation with you. Here, I'll post it again.
Read it. Is it wrong? Come to that, why did you bring up the number 45
anyway -was it only to make the irrelvant point that 45-30 30-20?
What could be the point of that in the context of discussing keel boat
_performance_?

Cheers

Herreshoff Pic... & more heel
 

Nav wrote:
Maths is is not double talk.

Your attempts are.


....when I try to clarify your
misconceptions

LOL

That's better Navvie.

DSK

Herreshoff Pic... & more heel
 

DSK wrote:
Nav wrote:

Maths is is not double talk.


Your attempts are.


....when I try to clarify your misconceptions


LOL

That's better Navvie.


Do you still think boats use spinnakers for beating to windward?

Cheers