-G'day Mike
I was thinking on similar lines but don't se much problem holding up
the ww hull. There is not an enormous weight off centre and a
vertical bit of box section on the ww side triangulated at the base
should provide enough support for the hull with a couple of tie down
straps to hold it against. Either that and/or a support under the
junction of the wing deck and hull. This would have to be to the lw
side of the c of g.of the www hull on its own.
If the crossbeams had a temporary controlling system such as a
farrier wishbone with a sleeve to allow sliding of the crossbeam, or
even a complete folding system as designed by Jim Shanahan then the
only difficulty is moving the lw hulls off the trailer and onto a
trolley as everything else can be controlled with a couple of
winches. Jim's system makes a lot of sense and would even allow
righting from a complete overturning.
My personal preference is to launch a folded system where the boat
can then be brought side on to shore and the mast then inserted-
possibly with sail attached. The crossbeams get winched out with
water supporting the system and you're away.
I have tried to imagine taking the folded boat out onto the water
and inserting the mast from the water. It seems theoretically
possible but would probably be excessively difficult in practice.

On another issue, I was wondering if there was any wat to get round
the dependance on carbon for making a free standing mast without
excessive weight. The closest I could come up with was , while
looking through a website on making bamboo fly rods, the testing of
tensile and compressive strengths and Young's modulus of strips of
bamboo. Rough calculations give a mast made of quality bamboo strips
a weight of about 2.5 times that of carbon. The technology for
utilising bamboo has come some way to making this practical, but
organising supplies off stream from flooring manufacturers would be
horrendous

Robert

-- In harryproa@..., Mike Crawford <jmichael@g...>
wrote:
>
>
> If you can keep that leeward hull in place as it rotates from
> horizontal to vertical, then there shouldn't be any problem with
the
> size of the mast. Given the length of the beams, a #14 winch at
16:1
> should be enough to bring the leeward hull into place with a 22m
wing
> mast. Though I'm not familiar with the size of winches used on the
> Harry's, my guess is that you'll have at least a #14, which is the
> smallest self-tailing size offered by some vendors.
>
> If this is not enough, it would be simple to double the purchase
with
> a block. If you want even more than 32:1, then you could have a
single
> line going from the trailer to the first beam, back to the trailer,
up
> to the second beam, back to the trailer again, and then up to the
> winch. That might be even be enough to lift your tow vehicle if
you put
> some muscle into it..
>
> ---
>
> For me the question then becomes how much help you're willing to
> require. If you can get a few people to lend a hand, then the
Harrigami
> setup described in the article should be fine. It's certainly the
> simplest and cheapest way to go, and there's a lot to be said for
both.
>
> I'd probably choose to spend more on a trailer to help ease the
> process, though. This would be partially to save on boatyard
costs, and
> partially to allow two people to launch in areas that don't
necessarily
> have paid help.
>
> I think even a Visionarry could be kept to an 11' / 3.3m
trailering
> width if the leeward hull could be stored on its side on the
trailer
> beneath the cockpit. My first thoughts on this would be to:
>
> - Create a bunk that could hold the ww hull upright on its own,
>
> - Create a detachable moving bunk for the lw hull with its own
> wheels that could be lowered and used to move the hull out away
from the
> trailer,
>
> - Add two long horizontal arms that could be used to hold the
lw
> hull in place the proper distance away from the ww hull, as well as
keep
> the trailer assembly together when launching and retrieving the
proa,
>
> - Give the lw hull bunk assembly the ability to pivot to
vertical
> without sliding towards the ww hull and trailer,
>
> - Add some sheet blocks to the trailer and akas through which
the
> winch line can be run,
>
> - Add two short vertical arms with soft rollers that could be
> inserted into the main trailer and used to catch the beams as they
> rotate down to horizontal,
>
> - Add some block attachment points to the lw hull so that it
can be
> winched tightly towards the ww hull once the beams are in place.
>
> I'm not exactly sure how this would be done in a real world
situation,
> though.
>
> The bunk keeping the ww hull vertical would need to be pretty
strong,
> especially if it's going to hold everything in place while on the
road.
> Perhaps it could be supported while by the lw hull bunk once it is
in
> place under the ww hull, and by a temporary support arm under the
> cockpit when the lw hull bunk is away from the main trailer.
>
> The lw bunk might need a roller bearing and expansion arm/track
to
> support it until it is moved far enough from center to get the
inboard
> wheels down (assuming the outboard wheels can be dropped while the
> trailer is still whole). The wheels would also need to pivot 90
degrees
> to make the transition from assembly to launch. Alternately, there
> could be two sets of wheels, but that seems a bit excessive.
>
> Ideas on how to improve this setup, especially on how to make
that lw
> hull bunk work, are welcome. I don't mind seeing my ideas trashed
as
> long as something better results. Rob could probably solve this in
a
> weekend if I were actually building a boat, but I've got five years
left
> of lurking in this group before I get to that stage.
>
> - Mike
>
>
>
> oceanplodder2003 wrote:
>
> > Saw that, my concern was at what mast length would it become an
issue,
> > considering that if I go for Rob's una rig I'm assuming the mast
must
> > be taller, and I think Harry's is longer than Harrigami to begin
with.
> >
> >
> >
> >
> >
>