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Thread: The Universal Hull,

  1. #1
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    Default The Universal Hull,

    by Warwick Collins -- is the topic of this week's "My Wooden Boat of the Week."

    My thanks go to our good friends at Seahorse magazine for copyright permission.

    I'm sure this will inspire many thoughtful comments, and I look forward to them.

    Please read and comment here: www.woodenboat.com/boat.

  2. #2
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    Default Re: The Universal Hull,

    That is an incredible concept. I wish I could see the lines plan but the video does give one a pretty good idea of the shape.

    Yes, I commented where you told us to, Carl.
    Goat Island Skiff and Simmons Sea Skiff construction photos here:

    http://s176.photobucket.com/albums/w...esMan/?start=0

    and here:

    http://www.flickr.com/photos/37973275@N03/

    "All kings are not the same."

  3. #3
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    Default Re: The Universal Hull,

    Bonus points to you, MAM. Thanks, Carl

  4. #4
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    Default Re: The Universal Hull,

    Thats not a universal hull. Definately not designed to the universal rule.
    "Twenty years from now you will be more disappointed by the things you didn't do, than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." - Mark Twain

  5. #5
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    Default Re: The Universal Hull,

    It looks interesting, "Universal" it may not be, and I don't think everyone will like its lines, but it does look like a very efficient way to cleave through the waves.

  6. #6
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    Default Re: The Universal Hull,

    Cannot find a place to comment where directed, so just a quick impression here. Looks just like a RIB without the collars attached. Wouldn't a RIB hull do all thoise same things?

  7. #7
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    Default Re: The Universal Hull,

    The "Comment" field is at the bottom of the page (www.woodenboat.com/boat).

    Thanks so, Carl

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    Default Re: The Universal Hull,

    I can see why Keyhavenpotter said it's like a RIB but RIB hulls tend to be simple Vs while the UH has obviously concave sections on each side, well aft. I found it very interesting the the designer chose to ignore the speed penalty of dragging a transom through the water (no rocker) but he said the trade off is worth it. Keeping the bottom/transom joint sharp causes the water to release the transom around 5 knots. From there the hull starts flying, right on through the theoretical (and traditional) hull speed/waterline limitation.
    Goat Island Skiff and Simmons Sea Skiff construction photos here:

    http://s176.photobucket.com/albums/w...esMan/?start=0

    and here:

    http://www.flickr.com/photos/37973275@N03/

    "All kings are not the same."

  9. #9
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    Default Re: The Universal Hull,

    seems like the stability could easily attributed to the small sail plan and shifting ballast (in the form of the skipper) on the windward rail... yes the flare acts to give stability on the lee side but it also acts as a hiking wing greatly increasing the effective righting moment of some one sitting on the rail.

    Why try such an odd bow and unusual sail plan on a experiemental boat? too many variables for me to draw much of a conclusion on the no rocker aspect of the hull... and I am currently experiementing with a no rocker design of my own... far more radical than the Universal hull

  10. #10
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    Default Re: The Universal Hull,

    I have examined that odd stem and have concluded it is for strength. The head stay forms the angle and the stem continues it.
    Goat Island Skiff and Simmons Sea Skiff construction photos here:

    http://s176.photobucket.com/albums/w...esMan/?start=0

    and here:

    http://www.flickr.com/photos/37973275@N03/

    "All kings are not the same."

  11. #11
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    Default Re: The Universal Hull,

    Here's a video of my design, the Universal hull carried to it's logical extreme. under almost all conditions the boat functions in planeing mode and only comes off plane and drags it's transom in very light wind... should be pretty fast with a outboard motor too!

    basically "plane or die" figuratively speaking...

    http://www.youtube.com/user/danoyes1#p/u/5/y-CD_0bum3E


  12. #12
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    Default Re: The Universal Hull,

    I must say that Collins' hull did not make my heart thump to look at it, but I suppose that blind obedience to thumping hearts does not make for scientific advancement. Many of us here are dewy-eyed romantics who, for better or worse, happily put up with the inefficiencies and quirks of century-old or even millennium-old hullforms because they are the most beautiful things made by human hands. When I saw this hull, I thought, Hmm, v-bottom, centerboard, firm bilge, recurve stem - catboat! Surely we can combine Collins' impressive performance with some old-school Mae West curviness.

  13. #13
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    Default Re: The Universal Hull,

    What good is a super stiff, un ballasted monohull when moving through big seas? Will it not remain square to the water when the water is at a 30 degree angle?

  14. #14
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    Default Re: The Universal Hull,

    There is nothing here that has not been done many times other than the quirky bow, although that is not new either. Moths have done the V hull to even more extreme than this. So much so that the boat would not even stay upright on its own. Some may tolerate a boat that tender but not many will. The single jib sail has also been done and works Ok on small boats where the loading is not so great but gets really iffy on larger boats. Not only severe loading on mast and forestay/bow/hull but the trimming loads get out of hand on the crew. Never been proven superior to the cat rig with a mast anyway. Some time back both cat/mast and single jib were tested on identical small boats and sail areas with no performance difference seen. Cat rig is the easier to handle unless you just like trimming a jib on each tack.

    On the powerboat, there may be a reason that a second crew is placed forward. To hold the bow down maybe?

    Notice that the video is done on a sheltered pond with good wind and no waves. How would this boat react in stiff chop or waves with the long straight keel and bottom? Advantage is in the lower wetted surface of the bottom with chines clear of the water and a narrow immersed hull. The price is very low lateral stability and low carrying capacity until that wetted surface advantage is lost when the chines go under water with greater weight.

    Interesting total concept that appears to work well in the range of conditions shown but I think some skepticism is natural and warranted until more rigorous demonstrations and data are shown.
    Tom L

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    Default Re: The Universal Hull,

    Thanks, Tom. I know Warwick is planning a great deal of testing during the upcoming months.

  16. #16
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    Default Re: The Universal Hull,

    I like this experiment: the unballasted sailing seems promising. My questions: (1) if the boat as shown were to be used for more than day sailing, say, a week's coastal cruise, would the gear load cut far into the advantage of the V-hull that provides narrow waterline when sailed upright? (2) When sailed upright, the hull seems tiddly, and in rougher water, on some courses, would the sail be rolling itself out of efficiency, similar to the problem of a pitching boat shaking the sail? --Wade

  17. #17
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    Default Re: The Universal Hull,

    Quote Originally Posted by wtarzia View Post
    I like this experiment: the unballasted sailing seems promising. My questions: (1) if the boat as shown were to be used for more than day sailing, say, a week's coastal cruise, would the gear load cut far into the advantage of the V-hull that provides narrow waterline when sailed upright? (2) When sailed upright, the hull seems tiddly, and in rougher water, on some courses, would the sail be rolling itself out of efficiency, similar to the problem of a pitching boat shaking the sail? --Wade
    Like any jib, this sail is not efficient downwind with no spar such as a whisker pole to hold it out in a good shape. With a whisker, it is much more trouble than a boomed mainsail. Nearly all small sailboats are unballasted, so nothing new there.
    Tom L

  18. #18
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    Default Re: The Universal Hull,

    Lots of photos here: http://universalsail.com/our-communi...universal-sail

    For instance:


    Doesn't this look familiar Tom? Take your Bluejacket hull form, increase the deadrise to 20 degrees, widen the chine flats a bit, cut the top 1/3 of the boat off to add lots of lightness and there you go! Maybe you missed a market niche by not designing a motor sailor rig for the BJ.

    The UH power video showed the same acceleration without much bow rise, just like your Bluejacket videos. Having that second guy up in the bow didn't hurt either.

    I was curious how the UH with the 15hp OB would compare to Graham's Marissa skiff (which has an bottom shape similar to the BJ24). It's within a few inches of the same L and B and the weight must be close too. The UH gives 16 kts with 15 hp. The power vs speed chart on the B&B website shows 17 kts for 15hp for Marissa.

    Phil Bolger (who else?) designed a boat much like this back in the 1970's. Flying Splinter (30 Odd Boats, p145) with 20 degrees deadrise and a flat run; no chine flats, though. 30' x 7', 3200#. It had a 135 hp OB and a 180 sqft dipping lug sail.

    The UH looks cool with that reverse bow and seems very able both power and sail.

    Maybe chine flats will catch on if they are combined with the unique topside appearance, like some of a Toyota Prius's appeal is a unique shape that says 'hybrid'. I'm all for new designs that perform with higher fuel economy.
    Denny Wolfe
    www.wolfEboats.com

  19. #19
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    Default Re: The Universal Hull,

    I found the article, and this discussion, interesting and informative. Thanks.

  20. #20
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    Default Re: The Universal Hull,

    When you get to be my age, you've seen a lot of these "breakthroughs" come and go. Anyone remember the "Sea Knife" that was going to revolutionize powerboat design? Check this thread in about ten years.
    Roger Long

  21. #21
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    Default Re: The Universal Hull,

    Yep. Revolutionary hull for the new water.

    More seriously, far from a universal hull this seems to be a highly specific hull suitable to a limited number of wind, electric or mechanical power chains.

  22. #22
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    Default Re: The Universal Hull,

    Denny, I do appreciate anyone's attempt to look into more efficient designs, especially in power since sail doesn't use fuel in the usual sense. If a hull is made light enough and/or narrow enough, you can almost ignore the hull speed dilemma. The flats on BJ are at least as wide at the transom as the UH and have reverse deadrise which would be a negative influence under sail. Deadrise is always a compromise for the many different goals of a design. In the UH, high deadrise and lightweight together make for a very tender boat that will not be acceptable to many. Taking the girlfriend out for a spin under power would require both to sit on centerline and part their hair in the middle too. As you know, Coyote is a bit like that. It is more normal for a high deadrise hull to have the aft chines well immersed to give acceptable stability and this always carries a weight penalty along with requiring more power and fuel. Still looking for a free lunch.
    Tom L

  23. #23
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    Default Re: The Universal Hull,

    The UH hull with the dreadnought bow is just beautiful, and the continuation of the bowline into the jib luff adds to the beauty. The jibsail mast allows three shrouds without fretting about mast bend, so there's a minimum of rigging (unless you went to an unstayed mast with partner clutter and more mast bend). I'd like to see a Hoyt jibboom attempted.

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