Will this work?

Discussion in 'Sailboats' started by usa2, Nov 28, 2005.

  1. usa2
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    usa2 Senior Member

    okay so im trying to perhaps build a wooden "rule beater" i guess you could call it. It will have a canting keel, and wingmast. it will be 28 feet long-32 feet with the sprit. Beam is 4 feet and draft is 4 for the keel-5 for the boards-rudders. My question is, will the interior frame idea i have designed work? It consists of i guess you could call it a "box" where the canting keel gear is held. There are then beam running for and aft of this to the stern. All the loads in the boat are directed into this structure, and the hull is to be light plywood fiberglassed. the crew weight will be around 700 lbs.
     
  2. cyclops
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    cyclops Senior Member

    Did you include the sketches?
     
  3. usa2
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    usa2 Senior Member

    i dont have any drawings on my computer yet. I will try to get them on. My scanner is a bit messed up right now.
     
  4. the_sphincter
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    the_sphincter *

    which rule are you trying to beat?
     
  5. usa2
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    usa2 Senior Member

    CRF-classic rating formula. The hope is we are able to build a boat that is the smallest allowed(26 feet i believe) in classic yacht races in maine,, and then show up and be able to outsail 40-50 footers.

    I still am having issues with the scanner, but if you can picture the small supermaxi Nicorette, that is what the shape of the hull is based on. Im currently trying to work out what we will do for canting keel gear and whether it will be block and tackle or hand pumped hydraulic. Any thoughts?
     
  6. the_sphincter
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    the_sphincter *

    go with a block and tackle. Much easier. Much faster, less likely to fail. You won't get a much interior room, but you're building it to race. You could also try adding racks, but I don't know what that'll do to the rating.
     
  7. usa2
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    usa2 Senior Member

    interior room is not an issue as we are not expecting to have any(except for the spinnaker well and the keelbox.

    Im thinking of using a 5 foot strut with a 200lb bulb. Im not sure what kind of purchase i will need for the block and tackle, but that is where the most stress will be in the boat, so therefore the middle section of the boat will be the heaviest built. There will also be 5 crew sitting on the rail.
     
  8. Doug Lord

    Doug Lord Guest

    Canting keel

    Why don't you consider seeing if you can buy stock Schock 40 canting equip; I think it is electro hydraulic and very reliable.
    What are you going to use for extra lateral resistance? Oh, nevermind....(I think I know..)
     
  9. usa2
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    usa2 Senior Member

    Lateral resistance.

    depends on several things.

    1). How much CBTF would cost to license on the boat and whether I would be able to make the forward foil retractable

    2) whether CBTF would sue me if I used what is known as TMF- named by Nicorette's designer Alex Simonis-and is implemented on Skandia, Maximus, and Nicorette.

    3. I like your K-Foil idea. How much would it cost me to aquire a 200 lb K Foil equipped bulb would you guess? Also, do you suppose it would be possible to make the wings angle of attack variable, so they are functioning like the canard or trim tab does on CBTF/TMF boats?

    4. Two slightly adjustable daggerboards.
     
  10. usa2
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    usa2 Senior Member

    How heavy is the Schock 40 equipment? Bear in mind this will be a very light, fragile, and narrow 28 footer. If we go with the block/tackle option, the boat very well may be narrower. Also, if the Schock equipment uses electricity, that puts it out of the running, because there wont be any batteries onboard.
     
  11. Doug Lord

    Doug Lord Guest

    Canting Keel

    1) You don't want the forward foil retractable;it is a huge asset off the wind. Talk to people that have sailed these boats and /or read Russel Coutts comments on his site. But yes, for a headstrong person that won't listen to CBTFco or Reichel-Pugh, it could be made retractable.
    2)Yes, I hope so. Unless you're nice and talk to them about an experimental project.
    3) Thanks. If you're serious e-mail Eric Sponberg; he can answer most of your questions about the kFOIL™. I believe we can include a variable angle of incidence system w/o too much complication.
    4)Takes up too much room inside on your size boat; too much hassle when sailing.
    ---------------------
    The Schock system is electric. Note that on a boat your size or larger it is likely that a hand moved canting keel will take up MUCH interior space. Unless it's part of the rule you should lose your electric "resistance"...
     
  12. usa2
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    usa2 Senior Member

    Interior room(or lack of it) is not a consideration on this boat, as there really wont be one. The aft part of the boat is the cockpit, the center is the keel wetbox and mast step, and the forward part is hollow used for storing the jib and asymmetrical spinnaker.
    The block and tackle system seems to be go for the canting keel system.
     
  13. RHough
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    RHough Retro Dude

    5 crew at 140# each? (you mentioned 700# crew)

    I thought the "standard" crew weight was 165#?

    A 200# bulb on a 4ft arm at 45 degrees cant adds about 560 lbs/ft to the righting moment.

    So total RM would be 700x2= 1400 + 560 = 1960 lbs/ft?

    If the sail CE is 15ft above the CLP that gives you 130# of sail carrying power.

    130# is only 14% of the 900#'s of crew and bulb. How light will the boat be?

    If you increase beam at the deck from 4 to 6ft you get:

    700x3=2100 + 560 = 2660 lbs/ft of RM and 177# of SCP for 19% of crew and bulb weight.

    You need 8-10% of total weight in SCP for good displacement performance. 15% plus for off-wind planing, and 27-30% to plane upwind.

    What am I missing here?
     
  14. usa2
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    usa2 Senior Member

    i scaled down the supermaxi nicorette pretty much so there probably are things that need to be adjusted which i havent compensated for. Im currently talking to a boatbuilder/designer and will post any updates.

    And the crew weight....im getting a bunch of teenagers for crew so they will be light. The average weight between us is around 700 lbs.

    Perhaps based on what you've said i can get a lighter bulb since the crew weight will be much of the ballast.
    We would use less crew, but we so far are figuring we need 1 to drive, one for the mainsheet, one for the jib/spinnaker, one for the keel, and a foredeck hand. it may seem like overkill, and perhaps i can figure out how to simplify it some more.
     

  15. Doug Lord

    Doug Lord Guest

    Radical Possibility?

    Does your rule limit the configuration of the boat? Could you consider a version of the Bethwaite/Bulloch "Super Maxi" with "buoyancy pods" and on-deck movable ballast? Very small pods; some weight in the keel and slidable on-deck ballast. Or Sean Langmans version of the same thing with a relatively small canting keel and wide racks..?
     
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