Subject: Re: Fw: [harryproa] Re: sailing Elementarry
From: Mike Crawford
Date: 1/30/2006, 5:09 PM
To: rob dalton

  No worries, Rob.  You're a great contributor to the group, and it's not too hard to figure out that you mean well.  At least if one thinks about it.  And for those who don't think about it, there might not be much you can do to help them.  Being less terse might help, but that's a tough call.  Some people might prefer shorter posts to longer ones with more explanation.

  Disagreement and debate are key to the discussion group in any case.  Otherwise ideas wouldn't progress that far.


  I fell in love with the visionarry after reading an article in Multihulls magazine.  I had bought several year's worth of back issues about a year ago, and found all sorts of boats over which to drool.  Eventually I came upon some harryproa articles and was just amazed.  Up until that point I had thought that the boat I really wanted didn't exist.

  I was looking for something with semi-private double or queen berths, the deck space of a catamaran, the speed of a large multihull, and the ability to demount, transport it, and store it on my property.  The Corsair F36 comes close, as does a demountable Contour 50, but both are quite expensive, and lack the interiors with more than one private area, and don't have that nice big cat deck.  Since a catamaran with queen bunks won't collapse down enough to fit on most roads, the closest thing I could think of was a Cat2fold boat ( modified to make one hull wider and the other narrower (above the waterline, of course).  In essence, a poorly-designed one-way proa.

  When I found Rob's boats, I realized that they do achieve the impossible.  Not only do they meet all my criteria, they do so for less material, at a lower cost, with greater righting moment, and more safety, than anything I'd contemplated.  I even love the idea of a double-ended boat when you're stuck in big weather, and shunting instead of coming about or jibing in serious winds would be quite a relief.  The ability to tack a schooner rig in low winds is also neat, allowing me to avoid being a winch monkey on a slow day.

  Rob has done a great job.


  However, I'm still an engineer at heart, and also feel the need to question and debate all the little design details.  I'm glad you do the same.

  Now that I've been going back and forth with Rob for the past year, and a little bit on the discussion group for the past month, I've resolved most of my questions.  The big remaining one is with the rudders.  Our thread helped a bit with the sturdiness of the design, but I'm still not happy with having to turn the rudders through 180 degrees for each shunt.  That's too much effort when lazy sailing, and too much time if you want to tack windward past another boat.

  Blind Date originally was supposed to have symmetric foils ( ) that wouldn't have to be rotated around when shunted. I asked Rob about this, and he said that a vertical foil would be too unstable, which is why they went with the swept foils. That made sense, but then I started looking at catamaran daggerboards, many of which are vertical. Are these too unstable?

  On a proa, the daggerboards would certainly need to be vertical if they're going to work in both directions. If you can make that work, then you should be able to make a steering system work with vertical symmetric foils, in which case you could skip the spade rudders as suggested by Paul Nudd, and just go with the rudders.

  Of course, you might say that boards in trunks are sturdier or more reliable, and if you're always pushing the boat to the edge, this is something to consider.

  I didn't want to pester the group too much with this, but I thought you might have some ideas.  I'll probably start another thread in a few months to resurrect the topic.


  Good luck with that PhD and the new job.  That's a lot of work.

  Thanks for the detailed explanation, both to the group, and in your last email.

       - Mike


rob dalton wrote:
Thanks Mike,
My wife says I'm socially autistic but I mean well.
Seriously, I would like people to find flaws in my statements as I genuinely wish to understand things better.
The forum is one of the few places for exchange of ideas about boats that seem relevant to me and the Harry concept is something i had been contemplating for years but not had the money or courage to try. Rob's approach to the rudders and the shorter ww hull has made it possible and the use of carbon for unstayed masts has lifted up one more notch.
I had hoped to be building one this last year but fate conspired against this and i have been assuaging my frustration by research on building materials and techniques and thoughts on how to 'improve'  the boats and interminable postings of my meanderings.
Most of my ideas are not worth the effort but ther are a few that Rob and mark say are possible and might be worth a go.
 Actually I need to post less and write more if I am going to finish off ny PhD before my new job .starts.
Again apologies for my apparant arrogance. I'll try a bit harder but i don't find it easy,