Subject: Re: [harryproa] Re: 8.5m multi "box rule"
From: "Rob Denney" <>
Date: 1/30/2006, 7:40 AM

Ready and willing!   Especially to see how it handles the thunderstorms!
Texel is  the same weekend.  Does not bother me much which one we do, both should be a heap of fun, and neither will let us enter officially.  However, Texel is just up the road from Belgium,  Switzerland is a major road trip.  Any suggestions for getting the boat there and back?
The wing mast keeps the telescoping section aligned, making it easier to hoist and lower.  The trick is to have the larger piece on the top.  Then there are no sail track problems and the uphaul line should not jam.    The ability to halve the sail area and the weight and centre of gravity of the rig is a handy attribute, not sure it would be sufficient to handle a 45 knot gust, but lowering the sail all the way down is a fairly simple task.  The ability to have the rig weathercock would make the 45 knots much more manageable than on the stayed rigs.
Interesting about the enormous reachers.  Do boats like the M20 (una rigged Marstom superlight tornado beater) use big reachers on the lake?  While I have to agree that they are successful on the M2's and Formula 40's, I still think that the added weight of sail and gear, plus the difficulty of setting and shunting it, and the beefing up required make it more of a liability on an Elementarry.  Be great to do some tests and find out though.
----- Original Message -----
From: dominiquebovey
Sent: Monday, January 30, 2006 3:18 AM
Subject: [harryproa] Re: 8.5m multi "box rule"

Rob, the 2006 Bol d'Or will be June 17-18.
Ready for 93 miles of lake racing?
I also do not think we'll have a chance against the M2s with the EL,
but hey, it will be fun. I only hope there will be more wind than in
2005. You're welcome to stay over at our place, naturally.

I agree about the importance of mast height, as limited as it is in
the M2 class to a meagre 16.6m ;-) Most racing boats here have mains
that are almost square. But nobody does it with unstayed una rigs,
because you absolutely need big reachers. A main only has not enough
sail area. And I do still believe, as most havigators here, in the
positive effect of a jib in front of the main.

I do not quite see how you can telescope a mast, even an unstayed one,
when sailing. Do you mean you do you do this at the harbour, or even
prior to assembling the boat? And how does the wing mast make this
easier vs. the round mast?

I am not sure the "extra height" is a problem in the breeze. IMHO once
you've taken a reef, the upper section adds some sail area high up,
but this is not so much of a problem.
There is the problems of surviving the 45kn of a thunderstorm. Wind
usually builds up to this speed from flat calm in 2-3 minutes, so you
better take all sails down - fast! And ideally a seasoned crew should
be able to keep the boat upright with a bare rig, for the 30-45min
this lasts. But if the boat capsizes, then you can wait for some power
boat to pull you upright (or gather the remains of the boat). On this
lake you're never more than 4nm offhore at its widest. In order not to
be washed ashore (which is mostly steep and rocky) you even ought to

--- In, "Rob Denney" <proa@i...> wrote:
> 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 -----
>   From: dominiquebovey
>   To:
>   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
>   But it might be possible to find sails designed for the 8.5m, therefor
>   DOUBLING the ratio! Might be overkill, and difficult engineeringwise.
>   --- In, "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
>   >   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
>   >   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
>   >   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
>   >   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
>   >   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, 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
>   >   >
>   >   >   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
>   >   > whitecap to be seen.  I'd simply love to sail one for a few
>   >   >
>   >   >   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
>   >   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
>   >   > >
>   >   > > 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
>   >   > > What is the "box rule" you are talking about,Mike?
>   >   > >
>   >   > >
>   >   >
>   >
>   >
>   >
>   >
>   >
>   >
>   >

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