Dennis, Hey other
Mike, Wow!
thanks for your input. If I missed anything, please
bring it back up as you have here. I wouldn't have
consciously avoided an issue, especially if I fubar'd it. Rudders
Linkage
- I hadn't caught that one yet... having all the linkage in one hull...
one less thing to rig, fatigue, etc. Reduce
steerage - Definitely an issue. I did think about
the reduced steerage ability as the hull lifts, and it did/does tally
up negatively. With lack of first hand knowledge, I
resorted to reasoning that there were lots of trimarans out there that
have the same issue. Fortunately the schooner rig, with
lower COE and able to balance the rudder forces help mitigate that. Access
- Yes, it sure would be a lot easier to work from the tarp than in a
dingy under the bridge deck. Definitely worth
considering. Twisting/Wracking Its
definitely a concern. I'd like to say that I have an
answer for it. I have the three cross beams in two
planes. This should have a tendency to be
stiffer than having them in one plane. You might have
also noticed that I ran the two primary beams all the way through the
windward hull, thus giving them plenty of support. All
this means is that to wrack the two hulls will be taken up by bending
of the beams and torsion of the windward hull. Definitely
not a desirable solution. Quantifying that is a can of
worms. By the time you simplify it enough so that it can
be solved with closed form solutions, your probably going to lose most
of the significance. I'll ponder some more. The
alternative is breaking out some finite elements. Having
the sails on the lee hull transferring loads directly into the hull
with the most contact and with the longer leverage makes a lot of sense.
This may be what I needed to stop riding this fense... this
is significant. Sail
handling I do plan
on putting life lines around and having steps down the domes from the
"Crows Nest" to the deck. I'm not sure if I glossed over
it somewhere, but the tops rotate open (you can see it in the first
part of the video) http://f1.grp. This is
not just for trailering, but for letting in the sunshine, or moon light.
In a crisis, I can open one and access the base of the mast
from the safety of the bridgedeck. I've been looking to
move the masts more toward the hinge line, for (a) this access, (b)
better angles for the sheet to the "crows nest" and (c) infringes less
on the interior. The down side... is it has less bury. Besides,
I'm still pondering a wing... no sail to reef... just feather the
wing. Also, makes tacking up and down the ICW a piece of cake even
with a schooner. I sure
like the picture you paint... for your situation. Sounds
so ideal. BTW is there an standardized height for the
ICW? One that I can go anywhere along it without
hitting bridges? And would you happen to know if this might be
universal in other parts of the world? I see you
have a second email waiting... Later, Dennis
LEE DESIGN 6-5. That's beautiful! It has a simpler, more elegant
look, the rigs are downwind (easier to watch in the rain), they're well
out of the way of the skipper and crew, and you gain a fair amount of
sail area down low for running and broad reaches. Which, given the
efficient sails or wings you intend to use, is really the only time
you'll need the extra sail area. I want one!
STEERING MOMENT. You also might want rudders on the leeward hull in
order to enhance steerage. When Blind Date went from the standard
rudders on the leeward hull, to beam-mounted rudders, it started
rounding up into the wind. Just a meter or two on each end can be
enough to go from laminar flow to turbulent flow, and that makes all
the difference. The further apart those rudders are, the less rudder
you'll need at speed in order to maintain a course.
TWISTING. Keeping all the major forces in the same hull would be
enough reason for me to personally get off the fence. That said, I do
think your three-beams-
ICW HEIGHT. I know a number of people who refuse to go past 60' air
draft. I'd probably go to 62'. There's a fellow who recently ran the
ICW with 65' air draft and made it through without a problem ( http://icwcruisersg
SAIL HANDLING. This one may be a wash. You'll be extremely safe
with an Atlantic rig if you handle the sails with the roaster open.
But if you really need to handle the sails in rough weather, you might
not want the roaster open over that nice king bunk.
CROW'S NEST. A wonderful idea. I personally insist on being out in
the wind as long as it's even remotely nice out. I'd definitely want
that second steering station and sheet control area for rough weather,
though. Either that, or a way to protect more of the crow's nest.
MAST RAISING. I think either of your ideas would work. You could
also get a stub mast in a second socket with a four-part
block-and-tackle, fastened to the center of gravity of the sailing
mast, roughly 33% to 40% up from the bottom. Hoist it up, position it,
drop it down. Switch to the next mast, repeat. The stub mast could
even serve as an emergency mast, if needed. Rafe Francke also has a
neat system on his cat2fold boat, which involves a sort of tabernacle.
I'll see if I can dig up his CD and post the videos to the group (he
has given permission; I just haven't had the time).
TRAILERABLE ENCLOSED SALOON. You're right: this is no longer a
showstopper. I'm sorry if I implied that this was still up for
debate. It was an issue in the Harry I've been pondering -- how to get
a table and benches inside the hull, but still keep that beautiful open
cockpit. And also an issue for my wife, who really wants the
protection. But the roadster certainly handles this.
ROB DENNY ON RECORD. I am annoyed with how often I scrap one of
Rob's ideas, only to later understand all the many reasons for choosing
it. And after I get over being annoyed, I'm grateful. That doesn't
mean I'd expect anyone else to agree with him, or that I'd take a
strong stance against an Atlantic rig (or a strong stance for a
Harryrproa instead). I'm just surprised at how little I'm able to add
to it.
---
That lee-rig design really is a good one. It even has me wanting a
schooner rig, even after all my reasons for wanting a single tall mast.
Nice job.
- Mike
On 7/27/2010 4:15 PM, Dennis Cox wrote: