G'day,
When is the Bol d'Or this year? Would be glad
to sail it with you of we can get the boat to and from Belgium to
Switzerland. Fun would be no problem, beating the M2's may
be.
A una rigged El with carbon/nomex, pressure moulded
everything looks like it will be near enough 90 kgs. An 8.5m
would be less than 150% of this
For light air sailing mast height is everything
(see Bethwaites book) as wind strength increases rapidly with height.
Therefore the highest mast possible would be the aim, rather than the largest
sail area. The problem then becomes what to do with the extra height in a
breeze. One possibility with a mast with no external fittings (forestay,
wishbone, etc) is a telescoping mast. Doing this with a round mast is
pretty difficult, but with a wing mast it would a lot easier. Would
not be as quick as hoisting/dousing a headsail, but in a race where it is
either windy or not, it has some potential.
regards,
rob ----- Original Message
-----
Sent: Thursday, January 26, 2006 1:24
PM
Subject: [harryproa] Re: 8.5m multi "box
rule"
Rob,
I am DEFINITELY interested to sail the
Elementarry, and yes you're
probably right, do the bol d'Or unofficially
with a crew of two.
One one the goals is putting my company name on the
sails o hulls, and
even unofficially it will get some media coverage... The
main goal
being to have fun!
The 8.5m EL would be less than 200kg
racing, the 8.5m cats weigh a
little less than 400kg, so EL needs about 2x
less sail area for the
same sail/displ ratio, Hence the Melges sails. Also
a way to limit costs.
But it might be possible to find sails designed for
the 8.5m, therefor
DOUBLING the ratio! Might be overkill, and difficult
engineeringwise.
--- In harryproa@yahoogroups.com.au, "Rob Denney"
<proa@i...> wrote:
>
> 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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