[MHml] Bi plane rigs.

[Scott Meyer]

Bill Gibbs wrote:
>  I am intrigued by stayless bi-plan rigs and boats like the Schionning
> Radical Bay 8000. 

I'm intrigued as well.  In one of the bulletin boards either from Schioning
or the people manufacturing the RB 8000, there was an authoritative sounding
comment to the effect that the static capsize windspeed for the RB 8000 was
28 knots... (SA 41 square meters, displacement 1100kg).

Compare with an F41 (static capsize windspeed 36 knots, SA 87 square meters,
displacement 7600kg). and an F25c (scw 28 knots, SA 40 sq. meters,
displacement
700kg).

How did they (or should they) compute static capsize windspeed for a biplane
rig?  Counting just one sail might be "correct" in some sense, but
doesn't seem
prudent.  I assume they count both sails and ignore blanketing, but if
28 knots
really is that number, it seems a bit out of whack.  How can it have the
same
static capsize windspeed and sail area as an F25c with a lower CE and an
extra 400 kg?

So the RB 8000 has half the sail area but one seventh the weight of an F41.
By the numbers it should be an absolute rocket ship, but the articles
describing
the boat don't seem to indicate that sort of performance, one in particular
noting that the boat didn't seem to do all that well in light airs.  Of
course boat
reviews are always maddeningly vague...

At any rate, if a biplane rig could really deliver more power with a greater
margin of safety, it would seem to be just the ticket for the ideal fast
cruising
rig.

-Scott