[MHml] Bi plane rigs.

[Bill Gibbs]

 I am intrigued by stayless bi-plan rigs and boats like the Schionning
Radical Bay 8000.  If you get the power to weight ratio up to Afterburner's
level, you solve the AWA problem as we never sail below an AWA of 70
degrees.  Dandy didn't get fast enough.  The next problem is the AWS
problem.  AWS diminishes as you fall off from close hauled, which normal
boats compensate for with ever larger headsails, jib to screacher to
spinnaker. Or in Afterburner's case, 2 jibs, 2 screachers, and 2 spinnakers.
Cat boat style uni-rigs don't seem to address this issue.  For sailing deep
a biplane cat seems the ultimate kite launching vessel.

Bill
Afterburner

-----Original Message-----
From: multihulls-bounces at steamradio.com
[mailto:multihulls-bounces at steamradio.com] On Behalf Of Roy Mills
Sent: Sunday, September 03, 2006 11:45 AM
To: multihulls at steamradio.com
Subject: [MHml] Bi plane rigs.

Snip

	He tried a bi plane rig on  his cat "Dandy" with a 23 foot LWL and
discontinued it after 2 years and 2000 miles. He initially tried it because
Lock said " the drag of the rig is not as important as the actual force
produced. Water drag and aerodynamic drag of the vessel itself are of a high
order and the parasitic drag of rigging wire etc is relatively small"  I can
go along with that but his comment is "Lock, I wish you had been right".
Lock had sent him a drawing of a
28 by 23 foot day sailing biplane cat,( that is extremely wide- a C Class
cat is 25 by 14) thought to be like an ice boat so it was fast enough to
always bring the apparent wind forward of the beam. "Dandy" 
would not do that. On a reach the leeward sail flopped about. It had virtues
he said.  It tacked faster than any other cat he ever sailed ( which was/is
one of my concerns) and he said that it pointed very high but was not fast
to windward. It would tack through 60 degrees but speed was low, when
bearing off to tack through 90 the VMG was still not good.

	 This seems not to be current experience with biplanes. Is it the
advent of unstayed masts that has made the difference, or larger sails in
proportion to the boat, or hull forms more suited to speed than cruising, or
all three, or more changes that have escaped me?

	Comments please.

	Roy Mills

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