G'day,
Fixed length is not a proa strong point. I am
not sure whether the weight and windage savings possible with a proa would
offset that or not. It would certainly cost a lot less. I would
love to have a go at designing something for it.. There are a few
areas that proas can exploit that are not open to cats.
Maybe wait and see how the Elementarry being built
in Belgium goes against the Tornados (this summer, I hope) and then look
at what should be scaled up and what can be reduced. Incidentally, I will
not be competing in the Bol d'Or (hope to be racing Blind Date in
Denmark), but the boat is available for charter if you or anyone is
interested. I would advise that you do it unofficially with two crew,
rather than officially with three.
Could you let us know the beam, mast height and
sail area of the M2 class, please. On the web page it looked like 70 sqm
upwind, plus a similar size screecher, but this does not tally with the Melges
sails. On this subject, I think the melges sails would be too light, and
not of optimum plan form for a light air boat which would have a near
rectangular main.
regards,
rob
Sorry for misquoting, David
mentioned this box rule naturally.
Yes these crazy boats are
incredible, I have seen them flying a hull
on flat water, 8kn of speed with
5kn of wind. They work by creating
their apparent wind. But their top speed
is estimated at 30kn.
The last horrible wind-less Bol d'Or was done
with "winds averaging 3
knots", the winner took 18 hours for the 100 miles.
That is beyond my
nerves anyway.
There are two classes. the M1
(only Decision 35 today) are machines
costing half a million swiss francs
(about the same in AUD), with a
racing budget of maybe half that on top of
it every year. The pre-preg
hull skin is less tha a millimeter
thick...
And they are low cost machines versus the f40 they had before! A
very
well known owner of D35 is bertarelli, yes the poor guy who
owns
alinghi and the america cup... Well I do not have any prospect
of
competing (financially) for some time to come, even if I am a
rather
optimistic type.... But this might be a job for a
Turbo-Harrigami.
But there is the M2 class, and the M2 are much more
"accessible" (for
a catamaran, around 100kCHF). The M2 are very close in
performance to
the M1, and I would be very happy to be in the 10 first of
the Bol
d'Or to start...
A HarryM2 would probably cost much less
than that (Rob, am I right?),
because of the structural advantage, and
would be competitive with
much less high tech gear than the cats and tris
in this class. It
would be nice to be competitive with wood-epoxy hulls and
minimal use
of carbon (only rig and beams), against all-carbon-kevlar
racing
machines. Kind of David against Goliath. But David still needs a
good
slingshot! And HarryM2 would still need a lot a sail.
To
decrease cost while keeping good performance, I am wondering if the
whole
rig for an 8.5m can be built around "standard" sails. For
example, a melges
24 sail plan (24m2 main, 10m2 jib), of which you
find (not very much) used
sails for reasonable prices, while only
needing to recut the jib a bit.
--- In harryproa@yahoogroups.com.au, Mike Crawford
<jmichael@g...> wrote:
>
>
> I think it
was David Howie who wrote about the box rule, and it just
> shows up in
my posts because I keep on replying in the same thread.
>
> Any ideas David?
>
> BTW, If I
wanted to race on Lake Geneva, I'd be much more likely to
> want
something like those Décision 35's for which you provided a
link..
> That was you, Dominique, wasn't it? In any case, I'm astounded
by the
> sail area carried by those boats, and am truly amazed with the
video
> that shows them flying hulls and sailing at speed without a
single
> whitecap to be seen. I'd simply love to sail one for a
few days.
>
> Those boats are way too finicky and
fragile for something I'd get,
> provided I could afford one in the
first place, but there's no denying
> that they are masterful speed
machines, especially for light air.
While
> I love the schooner rig
with flexible unstayed masts, I'm viewing this
> from the perspective
of racing single-handed in gusty conditions. In a
> real race, in
low wind, with crews that know what they are doing, I'd
> have a hard
time imagining anything beating a Décision 35.
>
> I don't truly want one of those fast cats for a variety
of reasons,
> but they sure do make me drool. I'm going to go
look at some Décision
> 35 photos now, and maybe watch that video
again.
>
>
> -
Mike
>
>
>
> dominiquebovey wrote:
>
>
> Hi,
> > Mike just wrote about an 8.5m "box rule". On Lake
Geneva, switzerland,
> > there are two multihull classes, M1 (10.8m
hull length,
> > Alinghi/Bertarelli is doing this) and M2 (8.5m), see
this link:
> > http://www.regates.ch/index.asp?ID=354.
>
> My conceptions of rig stiffness are somehow influenced by the
sail
> > areas you see on the diagram... And lake geneva is terrible
for wind,
> > with most summer races in ghosting conditions
(including the "bold
> > d'or"), but in spring and fall there can be
quite a lot of wind.
> > What is the "box rule" you are talking
about,Mike?
> >
> >
>
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