Project Proposal : proa design for handicapped sailors

Project Proposal

Why design yet another boat in the classic mold? Here's something different for a challenge.

A friend of mine is a paraplegic, who is paralyzed from the waist down and has limited use of one arm. We were kicking around some ideas for a boat that he could cruise.

The requirements were:
- sail powered
- coastal cruising with family
-- sleeping accommodations for 2 adults + 2 kids
-- head
- something he could sail by himself
- shoal draft, since he lives on the water with a shallow pebbly beach on Puget Sound
- highest performance consistent with his physical capabilities; racing with local multihull club desireable
- trailerable would be desireable, to make more cruising areas accessible

The concept that seemed workable was along these lines:
- multihull to minimize heel and maximize performance
- length around 24'
- shunting proa because it's difficult for him to move from side to side when tacking. With a proa he can be seated in the windward hull facing leeward and maintain that position for both tacks.
- mast inclined to windward. This allows him to be in a harness similar to those worn by hang glider pilots (or a glorified bosun's chair), suspended from the mast. A continuous loop line running from the harness to a block at the end of the lee hull and back makes it possible for him to "fly" there by pulling on the line, giving him a 2:1 advantage. A similar loop goes to the other end of the hull and to the cockpit. This gives him mobility to any place on the boat.
- Ballestron rig for easy shunting.
- roller reefing of both main and jib.
- accommodations in windward hull, rig in leeward hull, making it a Denny type proa (neither Pacific proa, with rig and accommodations to leeward, nor Atlantic proa, with rig and accommodations to windward)
- overhead track in the cabin so that he can simply hook his harness to the track and translate through the cabin.

Anybody care to take a crack at this?

 

Tom:

Man, are we on the same wavelength! I have a bunch of sketches for a boat very similar to what you're describing (but no formal drawings). Unfortunately I don't have much time right now, but let's keep in touch about this.

 

Like this?

Like this?

 

Actually I should have started another thread as soon as I actually wanted to submit a drawing. I'm discouraged from uploading the same image twice, though. Jeff, can you help us take the proa discussion into a new thread gracefully?

 

Good point Stephen - done. (fairly gracefully anyway )

And I didn’t have a chance to say welcome to the forums Tom. I really enjoy reading through every page of your web site so I am very happy to see you found our forums.

OK, now back to the discussion at hand…

 

Thanks. The site's a bit plain, but that's because I'm aiming for a high "signal to noise ratio".

I should have mentioned that the candidate sailor has full use of his other arm and routinely gets in and out of a minivan by himself, so that should help define the level of mobility.

I had in mind something a bit simpler than the sketch above. Something more along the lines of Rob Denny's designs or the .MI-6. With the mast inclined to windward. I like Denny's designs because they put the weight where it needs to be. Putting the foils in the windward hull could provide a measure of capsize protection because the lateral resistance disappears as the hull lifts. But the lateral separation between rig and foils may make balancing the boat directionally more difficult.

For the boat under consideration, it might be advisable for the cockpit to extend through the middle of the cabin so that the skipper can lean back and loop a mooring line around a passing dock cleat when landing.

 

canting mast to windward?

Tom, a great idea - but I think a mast canted to leeward would be safer - if the wind get's up, instead of dowsing sail, slowng down etc., and in the event of a gust: being rolled, with a winward canted sail, the leeward canted boat heels less and the force necessary to heel it more goes up faster: the more the proa heels the more the wind has to strengthen to heel it more.

What this amounts to is that if you cant the keel, say about 10 degrees - perhaps 15 at the most, the boat will not heel enough to dip the mast in the water, even in the strongest conditions. It is failsafe.

The other advantage, and this has to do with ultimate safety; If you cant the mast to windward and are flattened by a gust, it's certain that you will roll right over upside down and stay that way. THe center of gravity is to leeward with the mast horizontal.

The downside of course, is that you lose pointing ability earlier as the boat heels, than with a windward canted sail, where you actually gain.

 

A good looking proa

Check out hughes proa designs . Just type in Hughes proa on yahoo ro another search engine. It is a 26 footer well suited I believe for what you are venturing to do and can be built relatively easily.

cheers,

Carl mcIntosh
shakeena@shaw.ca

 

Hi Tom.
How is the situation with your project with the boat design for handicapped sailors?
-----------
Wing Drive

 

G'day,

The original post appeared before I was on this list. The answer to Tom's question is Yes, we would love to have a crack at it. In fact, a slightly larger version of a cruising Elementarry (http://www.harryproa.com/Elementarry.htm) would fit the bill with ease. If your friend is still interested Tom, please ask him to contact me, either on or off list.

Regards,

Rob Denney

 

It was an idea we were kicking around - never got to the serious project stage. He's currently building a new house, so I don't expect there will be a new boat until the kids are out of college - and they're young, now!

 

Maybe like this?

Designed by Brazilian disabled adventure sports promoter Dad Moreira. Used here at Parque do Sonhos, Socorro, Brazil on the 1 km long zipline "Panico."

 

Hi guys!

I introduce this item not to cross swords with anyone - especially Tom Speer or Rob Denny - I have much admiration for their work and input into this forum. I only want to show another point of view...

I recently came across the article below which changed my thinking somewhat and I decided to scrap a modified pacific proa design in favor of a traditional pacific design.

I guess it only proves that in things boating, there are no absolutes. It's just like the mono/multi debate - it'll endure as long as there are thinking minds out there.

The item is located at http://www.wingo.com/proa/johndalziel/index.html

Debate! Viva la difference!