Hey guys - need your help

Discussion in 'Boat Design' started by eightwgt, Apr 17, 2003.

  1. eightwgt
    Joined: Apr 2003
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    eightwgt Junior Member

    Hello first... Its my first post here. I am hoping I may get some help here. I have been looking at building the Wyoming, a Phil Bolger design... I love the shallow draft, love the large space for interior design, and really like its low power requirements... not to mention building it would be a breeze - though thats not my primary goal.... I am very worried about its sea worthiness... so I am looking at other ideas....

    My goals :
    1. Shallow draft
    2. Low Power Requirements / efficiant
    3. Sleeps 6
    4. Can handle a trip to the Bahamas from West Palm beach....

    Any advice ? I am open to ANY ideas on hulls... From classics, to plytugs, to ILAN trimarans... you name it.. Im game

    Thanks guys.....

    Tom M.
     
  2. badges65
    Joined: Dec 2002
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    badges65 Junior Member

    what size hull are you looking at???
    don
     
  3. eightwgt
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    eightwgt Junior Member

    Badges

    I am looking at a 40-50' Hull...... Or whatever I can accomplish my objective with.......

    Thanks
     
  4. SailDesign
    Joined: Jan 2003
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    SailDesign Old Phart! Stay upwind..

    eightwgt, how do you define "shallow" ?
     
  5. Tom Lathrop
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    Tom Lathrop Junior Member

    You are right to worry about seaworthyness of long narrow flat bottom powerboats. Ruel Parker has a 36 footer that is intended for the use you mention. Watching the weather is advised in crossing the Gulf Stream in any such boat though.

    A wave piercing displacement catamaran looks like a good choice. Speed in the high teens with low power in waves that would have most shallow monohulls in port.
     
  6. Guest

    Guest Guest

    Tom,

    Well your right.... I have been sketching my brains out.... Im looking at a trimaran actually. 40-45' Main hull beam of 6-8' and the sponsons / outriggers are a question.... Im looking at the CG vs CB and no need to say that its veryunstable - hence the tri concept, but I am trying to figure the righting arm of the sponsons vs their place ment in distance from the center of the hull.... I want to figure the minimum distance they can be placed from the main hull.... any advice ?
    Second..... I am going to Pay Ted Brewer as a consultant on the project design..... I can do a lot of the calcs, etc, but really like to get a pro involved in a unique project... anyone want to make a refferal ? I talked to a couple guys so far but at 7k + its out of my budget..... So anyone that can offer assistance and or a refferal would be appreciated....

    Thanks
     
  7. Tom Lathrop
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    Tom Lathrop Junior Member

    I would not venture to give any detailed advice on something that far out of my experience. A few years ago Yanmar had a power tri like you describe designed to show off their diesel outboards in a round the world venture. It came off pretty well, I think. You might look up some info on that since the basic design concept would certainly be up to your project.

    Ted Brewer can certainly do the job and is not likely to charge you an arm and a leg. From my limited experience, I'd say that catamarans are more suited to offshore conditions than trimarans, at least in sailboats. There have not been many power tri's though.
     
  8. eightwgt
    Joined: Apr 2003
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    eightwgt Junior Member

    Tom

    Thanks for the reply. Ted is not doing new designs anymore - only consultation.... so Im going to see if I can find some help, I am simply going to get Ted to help with preliminary design suggestions.
    I agree about the cats.... better offshore but Im not going to sail her, power only, and from my initial calcs I can get more efficiancy out of the Tri at less cost to build ( I think)
    Again, thanks for your input - all input is great....

    Tom M.
     
  9. SailDesign
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    SailDesign Old Phart! Stay upwind..

    eightwgt, be vewwy vewwy careful about power cats in roughish weather. Stability does not always mean safety or seakindliness. With a super-stable boat (cat, tri, quad, etc.), you will roll with each wave, over its full range of slope - with a less stable monohull, you can design it so that it doesn't roll with the waves half so much, and when it does, the motion is kinder.
    I know this sounds counter-intuitive, but it is so. A boat with a low GM (initial stabilty) will have a gentle motion, but may still have the large-angle stability needed to keep it from capsizing. Acatamaran will have stupendous low-angle (initial) stability, leading to a snappy motion in a sea, and have a poirt of vanishing stability that comes out of nowhere at a low angle. In fact, very close to the behaviour seen in flat-bottomed monohulls.
    The trimaran can be kinder than the cat, but will still suffer somewhat

    Steve
     
  10. eightwgt
    Joined: Apr 2003
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    eightwgt Junior Member

    Steve,

    Ted Brewer was telling me about the snappiness of the cat hull - how it has good stability but a very snappy roll.... My main objective is basically a non-sailing vessel (Im not a sailor) that has shallow draft, low power requirements (hence fuel efficiant) that I can have some fun in and safely take to the bahamas from Florida a couple times a year.....and sleep my wife and 3 kids on.... Id love to have a nice trawler, but too much draft, I love the looks of them but wont work for what I want to do.....

    QUESTION guys...... maybe this is a dumb one but Id love to hear some opinions. I was thinking, why not build a 35-40 cat, without the sailing rig.... and power it with a couple of small 4 stroke outboards.... I can park it, enjoy it, plenty of room, shallow draft, fuel efficiant.... But Ive never seen anyone do it...... is there a down side to that ??? Let me here what ou guys think of that idea.......

    Thanks
     

  11. Tom Lathrop
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    Tom Lathrop Junior Member

    Eight, Steve makes a good point about the initial stability and snappy roll of the multihull and flat bottom. Maybe the most seaworthy shape is a round cylinder with pointy ends. Problem is, humans could not live is such a thing without some sort of active stabilization system like a gyroscope, so we have to make our boats habitable. The most uncomfortable boat in our neighborhood is an old Navy 26' whaleboat. Very seaworthy but slow, wet and will roll your guts out.

    If you search, I think you will find a lot of information on power multihulls. That would be wise before striking out to simply but engines on an existing sailboat hull.
     
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