HP40F-cheap compromise or ingenious solution

Discussion in 'Multihulls' started by Sailcy, May 21, 2016.

  1. Sailcy
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    Sailcy Junior Member

  2. Sailcy
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    Sailcy Junior Member

    Just guessing. Is the conservative view holding the people out of expressing their opinions?
     
  3. Corley
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    Corley epoxy coated

    It's a cool concept, I hope it gets built so we can see it in action. Personally I'm most excited about his Bucket List proa and hope to sail it when it hits the water.
     
  4. CT249
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    CT249 Senior Member

    I was one of those who stayed away from this thread, but given you asked a specific question it seems rude not to give a specific answer.

    People may not be holding their opinions back because of "the conservative view". A lot of the time in boat design, "conservatism" is blamed when in reality, on objective criteria a design may not suit that many people. Some of the craft I own and love aren't very popular but it's just because they don't suit many people.

    Secondly, there are a lot of people who are so passionate about a type that they abuse anyone who isn't a fan. It's not "conservative" to try to stay out of flame wars.
     
  5. redreuben
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    redreuben redreuben

    Sailcy;
    The Harryproas have already been discussed vigorously on most yachting forums such as Sailing Anarchy and Cruisers and Sailors Forums as well as several threads here.
     
  6. rob denney
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    rob denney Senior Member

    Sailcy,

    I suspect the reason no one responded is because there is already a thread at http://www.boatdesign.net/forums/multihulls/40f-folding-proa-harryproa-55608.html

    In answer to the question/title, I would reply that it is both.
    The client had a long list of very specific requirements which could not be supplied with any other boat. So it definitely fits the second part of your question.
    Due to the build method (Intelligent Infusion http://harryproa.com/?page_id=1327) and the simplicity of the harryproa type, it will also be cheap. The compromises that have been made are, for this client and his requirements, very few.

    If you want more information on the boat or the build, let me know.

    Corley,
    Bucket List https://www.youtube.com/watch?v=ttXu3pRTzs8 edges closer. Look forward to taking you for a sail.
    Update:
    The windward hull is built and painted. Weighs 80 kgs on my bathroom scales. It's a bit rough as I am not allowed to make dust, but from 3m/10' or so it looks fine. The 2 halves of the lee hull are out of the mould, have the bulkheads fitted and weigh 80 kgs each. Maybe another 20 for mast and boom sleeves, foam bows, the centreline join, paint and antifoul. The beams are scheduled to weigh 25 kgs each and as they are filament wound, this will be accurate. Ditto the mast at 60kgs. I have just picked up the rudder moulds ($Aus400) and will build them next week. Based on the laminate and previous jobs, they will weigh about 15 kgs each. The rudder mountings on the beams have been through a few iterations, but are now simple and should weigh about 10 kgs each. Windsurfer masts for tiller extensions add another 10. Tramp, sail, battens, boom, winch, running rigging another 60. So, ~500 kgs.

    Figured out how to make spade rudders lift, so have reverted to these. They will turn through 360 degrees and kick up in either direction.

    The mast is now fixed instead of rotating (saves the cost of the bearings, the time to align them and means a slightly lighter mast) and the sail is tied to the mast rather than a track and slides. This works well on my model, will be interesting to see how it works full size. The weight saving is large, and it is all up the mast so worth a possible small drop in performance. It also allows the halyard lock to be failsafe without relying on strings to release it, which is a bonus.

    I built a wishbone boom (17 kgs), but then figured out a way for a conventional boom to work, which saves about 12 kgs, so will give this a try.

    Kite progress has continued. We can reliably launch kites from the boat and have got a more robust solution than the standard leading edge inflatable kites that will also fly in lighter breezes. Kite gear won't be fitted to the boat until the sailing version is working and racing.

    Bucket List now has a cockpit. Adds ~15 kgs, but it is in the right place and will make it more comfortable, so worth a try. It can be easily removed if required and it can be stored in the hull, so we can still get 4 boats in a container. See http://harryproa.com/?page_id=1173 for a picture.

    Been a busy year for Etamax but they have finally got far enough ahead to put someone onto the mast and beams, which should be ready in a couple of weeks. Then I will go down and put the lee hull together, put it on a truck and bring it up to the Gold Coast. All going well, it will be sailing soon after.

    Chris,
    If you have any comments to make about the boats, do so. If you are only entering the discussion to stir up a flame war or make personal comments, then you are correct, it would be better if you stayed away.

    redrueben,
    I know about the SA, BD and Cruisers forums, but was not aware of the "sailors forums"? Is there one I have missed, or was this just a generalisation.

    rob
    www.harryproa.com
     
  7. redreuben
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    redreuben redreuben

    Rob, Cruiser and Sailing forums is just the full tile for Cruisers forums.
     
  8. Sailcy
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    Sailcy Junior Member

    Thanks Rob! I didn't mention the earliest tread.
    I think that folding approach is a huge step forward for proa popularisation. The same step was taken by Dragonfly and Farriers in order to survive as cruisers. But having 2 double cabins in a 40ft trailerable folder inexpensively build and be able to fit in a monoslip is a different story. Wish to see it in action!
     
  9. Sailcy
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    Sailcy Junior Member

    Actually, I stick with positive feelings using term "conservative". By this I mean people want to "conservate" well proven approaches. But that approach was a breakthrough at the beginning. The keel yachts appeared just over a century ago and modern catamarans are even younger. Yeah, an old formula- speed, comfort, cost
     
  10. CT249
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    CT249 Senior Member

    Rob, I was answering a direct question from the point of view of one of those who had seen the thread but decided not to post. There was and is no intention to flame anyone.
     
  11. Sailcy
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    Sailcy Junior Member

    Could anyone refer please to the turning point when in the western world proa became a catamaran?
     
  12. Gary Baigent
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    Gary Baigent Senior Member

    Cheers, one of the first modern Western proas (if not the very first) had equal length hulls - shift the rig to centre between hulls and you have a catamaran ... but with one hull carrying accommodation - which wouldn't be very clever.
    Sure they are similar (cat/proa) but they are also VERY different. The Denney "flying" proas have a shorter and to windward float which carries accommodation - which is quite different to the Newick lean-on-the leeward hull (Atlantic) proa setup. And then there are other variations based on the traditional and ancient Pacific proas. And this talk could go on and on ... and probably will.
     

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  13. sigurd
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    sigurd Pompuous Pangolin

    In use if not in engineering I think the 'atlantic' proa is almost the same as the hp, just the mast on the ww hull for the ap. 'pac proa' is more different as it has less weight to ww. Pac is ment to fly ama almost always so it's more of a mono whereas hp and ap ww hull is so heavy they can't fly without more wind. It is a pretty flawed terminology because the polynesian /voyaging/ proas had houses near the ww hull so were infact harryproas. The biggest boats they had were catamarans I think.
     
  14. lucdekeyser
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    lucdekeyser Senior Member

    In addition there is the option of folding bows as shown on the Exhilarator 40F
    What is your take on that feature?
    [​IMG]
     

  15. redreuben
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    redreuben redreuben

    Well from the graphic I don't see the point as the folding mechanism sticks out further than the shortened hull !
    It kinda defeats the whole Harry ethos of simplicity but I guess for some people the added complexity is going to be a necessary evil.
    There will be a lot of force from many different directions trying to rip that bow off and it will need to work in two directions as well, quite the engineering challenge.
     
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