hi mike,
thanks for the reminder about cat2fold. it really is a slick idea, and i had not seen those long videos the first time i heard about it.
thanks also for the heads up on the cost of winter storage. i've long liked trailerable boats, mostly for the easy change in sailing venue. but now i appreciate that there other advantages as well!
you might recall that a few months ago i started a thread on pantographing, argueing specifically that when sailing off the wind the weight of the ww hull was best positioned a bit aft instead of directly tranverse. at the time i let folks convince me that the moving parts and extra weight were too disadvantageous.
you however now have me thinking about it again, as it could serve the dual purpose of better performance on the water, and a means to trailer off the water.
consider a 40 ft harry proa (more on this specific length later), with a 20 ft beam. pantographed to 60 degrees, the beam would be halved to 10 ft and the hulls would be displaced 17 ft fore to aft. given a 30 ft ww hull, the total pantographed length would be 52 ft.
one could imagine, twice a year, hiring a flat bed 18-wheeler to transport the boat to a backyard, or even to florida, for the winter, when collapsed to a 10x52 ft footprint.
here's another folding idea: do it farrier style, with the lw hull being treated as the ama. folding would happen on the water and the mast would be stored on the ww hull when collapsed, as follows:
when rigged and floating, one would first use a gin pole to demount the mast, lay it on the beams, and roll it to the ww hull. then undo the beam bolts near the ww hull, lifting the beams directly upwards such that the lw hull rotates 90 degrees around the longitudinal axis and fits snugly underneath the cockpit of the ww hull. motor into the dock and trailer up the ramp. reverse to launch.
does ian have a patent on this mechanism? 20 ft wide beams would be 20 ft tall on the road. how much of a problem is that?
why 40 feet LOA? because it fits in a container. rob could make all the KSS flat panels in australia and ship them stacked flat worldwide, for super cheap because dozens of boats could fit in a single container. he could include in said shipment all the jigs needed to fold and glue them together. i believe we have three people in the market on the american east coast (mike, gardner, me). shipping could hence be a third, and from a builder you trust.
have you ever considered joint ownership. how many days would you sail a harry proa per year? were i to buy one, i'd have two boats, and a wife who doesn't like to sail. would make much more sense to share a harry with someone else.
lastly, rob, your website is slooow. also, the mast heights are missing from all the specs. they're about LOA for a schooner rig, right? and a bit longer for unarig?
ben arthur
weta #358
chesapeake bay
--- In harryproa@yahoogroups.com.au, Mike Crawford wrote:
>
>
> FOLDING MECHANISM
>
> I know I'm in the minority, but my favorite folding mechanism by far
> is the scissors beam system created by Raphael Francke for his Cat2fold
> catamaran.
>
> http://www.cat2fold.com/images/albums/5/5_6.jpg
>
> You can also see it in operation on the actual boat at:
>
> On-water unfolding:
> http://www.youtube.com/watch?v=n8eL2a_xqkc&t=99s
>
> Interesting mast raising system with "stub mast / tabernacle":
> http://www.youtube.com/watch?v=n8eL2a_xqkc&t=30s
>
> Reasoning:
>
> - It's proven and in use.
>
> - There's no worry about how much bury to have in a telescoping
> mechanism -- the entire beam is "buried" when you secure both ends.
>
> - It will allow for smooth folding and unfolding by one or two
> people, on the water, without worrying about one side jamming.
>
> - There are no worries about how to secure the expanded system in
> terms of allowing it to be tight without stressing the connection.
>
> - The whole beam will be quite resistant to wracking loads due to
> its height and connections.
>
> - No worries about how much free play to have in the mechanism.
>
> - Uses a standard winch handle to fasten two heavy-duty connectors
> per beam (the connectors taking primarily shear loads).
>
> Some will argue that this could add 50 kg to the boat versus
> telescoping beams. Maybe more. I won't argue against that. Plus,
> there's a fee to Raphael of probably about $1,200. That's a lot more
> money than something that's free.
>
> For me, though, the benefits far outweigh the costs. Just seeing him
> expand that boat on his own at the launch ramp has me completely sold.
>
> If I ever wanted to transport the boat, I'd want a similar three-axle
> trailer (see the video from the start), and would definitely want a
> fixed trailer with the boat expanding and contracting on the water. I
> have an expanding trailer for my current multi, and it's such a pain
> that we haven't used it since we bought the boat in 2004. It would be
> sooo much nicer to just drive onto a fixed trailer and be done with the
> process.
>
> Likewise, if I were to pull into a monohull slip, I'd want to do the
> folding on the water as well. Both ways I'd want to do it either alone,
> or with my wife's help. There aren't many systems that could claim to
> allow this to happen.
>
> - Mike
>
