Subject: Re: [harryproa] Re: one rudder proa, first sail
From: "Rob Denney" <>
Date: 2/24/2006, 2:42 AM

So many options, so little time (and money)!!
Thought about this and it is definitely easier.  Drawback is that the air when the sail is reefed would have to flow over the wing then over the gunter. 
----- Original Message -----
From: Robert
Sent: Friday, February 24, 2006 2:52 PM
Subject: [harryproa] Re: one rudder proa, first sail

I was thinking of an over size track in the back of the wing mast 
supporting a gunter This allows a skinnier top section and
flexibility for the gusts and the junction would be almost seamless.

--- In, "Rob Denney" <proa@i...> wrote:
> Could extend them, but easier to use the beams.  Also fun to push
past the limits to see what happens.  Not yet sure what will happen
on the bigger boats with one rudder.    A system like you suggest
would work and be pretty easy to build.  I don't like the idea of
extra headsails as there is nowhere easy to sheet them and they
involve going on the foredeck.  Could be done, though.  For light
air, I like a telescoping mast, but won't know about this until I
build one.
> No rush with the spreadsheet.  I agree about the una rig.  Should
get some sailing photos on Sunday or Monday.
> regards,
> rob
>   ----- Original Message -----
>   From: David Howie
>   To:
>   Sent: Friday, February 24, 2006 4:42 AM
>   Subject: Re: [harryproa] one rudder proa, first sail
>   Just some idle thoughts. Could you extend the rails past the
beams to get the
>   rudders further aft,maybe some support off the hull? What about
a simple
>   system utilizing bungee cord for the two rudder set up? My idea
would be
>   uncleat a line and the rudder pops up, pull the same line and
cleat it and the
>   rudder is locked down. Sounds harder than the reality.
>   So now, what about harry with a una rig (with a wishbone?) and
rudders that
>   raise and lower easily, then staysail/assymmetic for light airs
downwind in
>   the light stuff?
>   I haven't got around to cleaning up the materials/price sheet
yet, got busy,
>   will try to do it this weekend.
>   BTW I think the una rig looks slick.
>   ------ Original Message ------
>   Received: Thu, 23 Feb 2006 07:48:34 AM MST
>   From: "Rob Denney" <proa@i...>
>   To: <>,     
>   Subject: [harryproa] one rudder proa, first sail
>   g'day,
>   Sorry I have been off air for the last couple of weeks.  Got a
bit obsessed
>   with the single rudder proa.  Anyone with any unanswered
questions or emails,
>   please ask/send them again.
>   Following on from the successful "una from a schooner" rig and
success using
>   the aft rudder only, I have tried to build a single rudder that
was moved from
>   end to end.  To minimise the work involved, I used the beams as
supports.  One
>   of our clients was keen on drum rudders so I thought I would
give these a go.
>   Mk 1 was a 300mm dia 300 deep drum.  Heavy and draggy so it was
chainsawed and
>   I made a T section with the ball races in the top.  Building it
was possible
>   without a lathe, but would have been much easier with one. 
>   First plan was to have it running on a couple of strings between
the beams.
>   Looked ok, but did not work.  Next was a couple of 20x 50 strips
of glassed
>   timber between the brackets.  This works well, except the rudder
>   floated, a nuisance as I had the runners on the top of the
strips instead of
>   under them.
>   Despite the rudder being 33% of the loa from the end (was 25%
with the fixed
>   rudders), it steered ok.  Interestingly, it luffed better than
it bore away,
>   whereas previously any difference has not been noticable. 
Bearing away,
>   particularly at slow speeds was novel.  The whole boat would
climb to windward
>   while the bows slowly turned downwind.  Had to stop and reverse
the first time
>   I tried to get around a moored boat.  The faster the boat
sailed, the less
>   obvious this effect was.  Helm balance was excellent, could
leave it alone
>   from broad to tight reach (didn't sail ddw) and the boat tracked
>   A first for me was that nothing on the prototype broke!  Sailing
>   reached 13.1 knots on the gps (not much breeze as you can see in
>   pictures), and everything felt really good. 
>   The drum and tracks weigh about the same as the old daggercase
boxes, but
>   could be lighter.  The difference between the 2 rudder schooner
and the single
>   rudder una is about 30 kgs and less drag, which is a big deal
off a 130 kg
>   boat.  Must weigh it next time it is off the trailer. 
>   The system works, but needs the following changes.  A solid stop
instead of
>   rope to keep the rudder vertical, lower the tiller, put a kink
in the tiller
>   extension to get it under the rails, and runners under the rails
to stop the
>   rudder floating up when shunting.  The drum works really well
(thanks Col) and
>   definitely has a place in future proas.  The end to ending is
good for a
>   little boat, maybe for a race boat, probably not worth the
hassles on the
>   bigger cruising ones.   
>   Should have the fixes done and sailing again on Sunday.
>   There are some pictures in the photos section of the harryproa
chat group.
>   regards,
>   rob
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