-I reckon you may be going too skinny with the hulls. The lee hull has
to be able to take the whole weight with significant transfer to the
bows. I work on the whole weight of the boat causing the lw hull to
depress to no more than half the depth of the bow when level. The
crossbeams also need a bit of bury on the lw side as that is where the
maximum loads are
About the rudders. I am working on having a flare supporting the beams
on the lw side and in the flare, just to the bow end from the
crossbeams , incorporating a shaft such as on Harriette. This way the
flare only has to be a few inches plus half the width of the rudder,
from the hull. This reduces the leverage on the shaft by about 4-6"
and doubles the bury, as well as allowing the rudders to stay on the
hull when crossbeams are removed.
Don't know what you don't like about using the cabin area for the
bury of the crossbeams.I presume you will have a sleeve in the ww hull
to separate the crossbeam from the internal space. You just have to
beef up this outer sleeve. I plan on a 3m wide ww hull, a 1.2m wide lw
, allowing collapsing to 4.2m and expanding to 6.5, with the cabin
area supplying the support for the outer sleeve and having only one
part crossbeams. To trail, I will have to either take them separately
or slide the lw hull under the ww on its side. This 3m limit allows
for wide load trailering, which in my area, is allowable as long as
you have a sign front and rear and travel during daylight. Any wider
and it gets a bit more difficult. I have a place near a good harbour
and only plan to take it home if I have to go away for any length of
time, otherwise I can simply take it up on the hard at 4.2 m wide or
leave it moored. One day I hope to sail to NZ as it is only across the
ditch from my place on the coast at Eden NSW
Please can you post a picture of the V mounting. I have a hard time
envisaging a system that can be removed easily but is secure at sea.
Robert
-- In harryproa@yahoogrou
>
> Oh, on a related note, I have redone my calculations for buoyancy on the
> hulls and reduced the ww hull waterline beam to 2'. From my calcs, this
> gives a ww displacement of 2,188 lbs and a hull weight (not
including the
> deck stuff) of 535 lbs. The lw hull at 45' with a 1.5' waterline
beam has a
> displacement of 1910 lbs with a hull weight of 500 lbs. If I allow
another
> 500 lbs for the cabin and 500 lbs for machinery (batteries,
outboard, etc),
> I get a full up weight of 2000 lbs with a displacement of 4000 lbs, so I
> think I have allowed for enough weight for crew and supplies.
>
> I didn't mention explicitly before, but I have reduced my target lw hull
> length to 45'. That is the 28' length of the ww hull, plus 2
removable lw
> hull extensions of 8.5' each. I can tell from reponses that I have not
> explained my mounting method for the hulls clearly. There is a V shaped
> bracked I have used on a nesting dinghy. One end will attach to the
main lw
> hull. This is the female part of the V. A male flange will then be
mounted
> to the removeable section, so that you can just drop the 8.5'
section into
> the female V and it will slide into place and be held there. For
additional
> security, you would then want to bolt it tight, but the hull is held
> together firmly by the bracket before you do that.
>
> As always, I am looking for more feedback.
>
> One specific request area: How does the rig come apart on the other
> trailerable? just a mast and boom; so how does the boom come off?
Can you
> leave the sail in place when you remove it? What are the dimensions and
> estimated weight of the mast, boom and sail (seperately)
>
> Thanks,
> - Gardner
> York, PA
>
>
> On Sun, Jun 22, 2008 at 6:04 PM, Gardner Pomper <gardner@...
> wrote:
>
> > Hi all,
> >
> > Ok, I have uploaded the modifications to the trailerable PDFs to
allow for
> > the different underwing clearance for the ww and lw hulls. This
allowed me
> > to add a bench/storage cabinet to the galley area. I also extended the
> > hardtop to cover the flip down walkway, so the drawings show the
boat the
> > way it will normally be in the water; the whole 10'x11' cockpit
area will be
> > covered with a hard roof, from which roll down clears can enclose
it against
> > any weather. This can all stay in place when going in and out of
the slip,
> > and there is very little additional work to trailer it this way as
well.
> >
> > I have drawn the visual for putting the boat in a shipping
container. I am
> > cutting the measurements very close, so I don't know if that will
work or
> > not. I am assuming that I will need a 108" high, top loading
container. So
> > far, none of the shipping companies have gotten back to me on what
the cost
> > is for a container from Panama to Philadelphia or Baltimore, so it
may cost
> > more to do that than to get it delivered. I would still like the
option of
> > shipping it to New Zealand. I am not sure yet if this is a boat
that should
> > cross the Pacific.
> >
> > The steering remaings as one of my bigger concerns. I am unclear
if there
> > is some way to put the rudders on the beam, while still allowing
the boat to
> > extend its beam from 12' to 20'. I am willing to increase the max
beam to
> > 14' if this will make a big difference.
> >
> > The steering of a proa is still unclear to me in general. If I have 2
> > rudders, and 2 tillers, what happens to the tillers when I shunt?
Do the
> > tillers have to flip up overtop of the rudders, since the rudders
flip 180
> > degrees? How do I do that on a boat where the helmsman is 15-20'
from the
> > rudders? Do I need to handle both tillers at the same time? Plus,
I need to
> > handle the sheets to swing the boom across. How do I do this
single handed?
> > Can the rudders be connected together with a fiberglass pole, and
then I
> > just have 1 extension tiller to that pole?
> >
> > I definitely plan on single handing, and so far it sounds like a
lot of
> > running around on the tramps, using 4 hands at a time. I am sure
there is a
> > better way, but I am not clear on it yet.
> >
> > - Gardner
> >
> >
> >
> > On Sun, Jun 22, 2008 at 1:29 AM, Robert <cateran1949@
> >
> >> -There is no need to bury the fatter beam all the way through
the ww
> >> hull when expanded, only enough to support it. As the loads are
> >> significantly less than the other joins,. it doesn't have to be that
> >> deep, I reckon you could get away with 18" to 2'.The only problem is
> >> beefing the parts up for the compression point loads. The contact
> >> areas are slightly fatter to make for minimum slack at the various
> >> expansion widths, while slightly narrower elsewhere to allow easy
> >> movement between, so the extra carbon is easy to add at these points.
> >> This gives you about another 4' With suitable triangular bracing, you
> >> could reduce the bury to 4" such as on Farrier tris but that would
> >> increase the complexity.
> >>
> >> For the bows, I feel a hinged system would allow easier
alignment, and
> >> if you need to completely remove them, simply remove the cotter pin
> >> and pull out the axle. Much easier to align the hinge on the outside
> >> for the first attachment than try and push bolts through with someone
> >> on the inside of the hull quickly getting a nut on,
> >> Robert-- In harryproa@yahoogrou
<harryproa%40yahoog
> >> "Gardner Pomper"
> >>
> >> <gardner@> wrote:
> >> >
> >> > I am not sure what you mean by "how to get another 5 feet". Do you
> >> mean in
> >> > beam or in length? The outer beam already buries all the way
through
> >> the ww
> >> > hull to the ww side. Sorry, I am just not following. Can you
elaborate?
> >> >
> >> > I was not really trying to shorten the boat for slip storage,
> >> although I can
> >> > see that could help when I rent a slip. I have a dock, so I
wasn't that
> >> > concerned with that. I just want the boat shortened for trailering.
> >> I am not
> >> > sure of the max height I can trailer without permits, etc, so
8' bow
> >> > extensions that hinged up would take my height to about 13
feet, which I
> >> > thought was probably too high.
> >> >
> >> > - Gardner
> >> >
> >> > On Sat, Jun 21, 2008 at 12:12 AM, Robert <cateran1949@
> >> >
> >> > > -I can see how to get another 5 feet or so by making the
cabin edges
> >> > > strong enough to allow the outer beam to have a bury of 2'
into the ww
> >> > > hull. This would allow the through beam rudders and still
have plenty
> >> > > of narrowing for slips. Still reckon a hinge on top would
allow the
> >> > > bows relatively easy shortening for being left in a slip
> >> > > You have worked out the tolerances pretty fine. I reckon it
should
> >> > > work-- In
harryproa@yahoogrou
> >> <harryproa%40yahoog
> >> > > "gardnerpomper" <gardner@>
> >> > > wrote:
> >> > > >
> >> > > > I have posted new versions of my ideas for a 50'
trailerable in the
> >> > > Gardner's Layout folder, if
> >> > > > anyone is interested.
> >> > > >
> >> > > > The idea for this boat is one that can be trailered, or
shipped in a
> >> > > container, but is ordinarily
> >> > > > left in a slip, so is just collapsed to a 12' beam. This
allowed me
> >> > > to basically move the seating
> >> > > > out from the galley area, so that I can have a real galley,
as well
> >> > > as a queen and a single.
> >> > > >
> >> > > > I am retaining the idea of bows that remove for trailering or
> >> > > containerizing, because that lets
> >> > > > me put a very long lw hull without the awkwardness of trying to
> >> > > trailer a 50' boat.
> >> > > >
> >> > > > I have absolutely no idea how the steering would be set up
on this,
> >> > > how the rudders would
> >> > > > mount, etc. I am hoping that someone can help me out with
ideas for
> >> > > that. I would be willing
> >> > > > to go with fixed rudders if I really have to in the leeward
hull,
> >> > > but I don't want a draft of more
> >> > > > than 30". Lift up rudders would be preferable.
> >> > > >
> >> > > > Thanks for any feedback.
> >> > > >
> >> > > > - Gardner
> >> > > >
> >> > >
> >> > >
> >> > >
> >> >
> >>
> >>
> >>
> >
> >
>
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