[MHml] Bi plane rigs.

[Roy Mills]

At 01:02 PM 9/3/06, you wrote:
>  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.

         That is what I thought, for whatever reason or combination of reasons.

>  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.

         He did not find sailing deep to be a problem really, both 
sails were working. They did try a square sail between the masts with 
both working sails wung out on opposite sides but found it was more 
trouble than it was worth and would not let them get onto any sort of 
a reach, which is where boat speed is better as you know. The VMG was 
better, he said, with both mains on the same jibe, just be careful 
when jibing so as not to tangle the booms.

          Yes, I would think that a kite would be a very useful 
addition to a performance oriented vessel and crew. Nuff said.


>Bill
>Afterburner

         Roy Mills


>-----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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