Why no aerodynamic control/stabilizer surfaces on high speed cats?

Discussion in 'Boat Design' started by RatliffFranklin, Jan 24, 2007.

  1. RatliffFranklin

    RatliffFranklin Previous Member

  2. kach22i
    Joined: Feb 2005
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    kach22i Architect

    http://www.globalsecurity.org/military/systems/aircraft/f2y.htm
    I don't think you can take one platform with a different mission and just apply it to another type of craft altogether. However let's for argument's sake take a look at some high-speed catamarans and see if there is a complete lack of aerodynamic consideration just to stay on topic.

    [​IMG]
    http://www.ferries.gr/dodekanisos/ferries.htm

    [​IMG]
    http://www.marad.dot.gov/education/adopt_a_ship/ship gallery.htm

    [​IMG]
    http://www.pride2.org/NewPrideSite/Europe/Logs/EuTeach091700.html

    [​IMG]
    http://www.mahle.com/C125705E004FDAF9/Print/W26FJGYT089MARSEN

    [​IMG]
    http://www.hornblowermarine.com/highspeed.html

    Images above found doing a Google "Image" search:
    http://images.google.com/images?hl=...G=Google Search&ie=UTF-8&oe=UTF-8&sa=N&tab=wi

    I see no fins, wings and other aerodynamic control surfaces in the images above. I also do not see these type of control surfaces on hovercraft that use waterjets or water screw propellers and SES (surface effect craft) ships using water type propulsion.

    If form follows function, then there must be a solid reason for this, right?

    http://www.hoverclubofamerica.org/forum/index.php?showtopic=779&st=90
    http://www.hovercraft-museum.org/vt1.html
    [​IMG]

    http://www.hoverclubofamerica.org/forum/index.php?showtopic=460&hl=surface

    [​IMG]
     
  3. RatliffFranklin

    RatliffFranklin Previous Member

    Apparently you don't know what "high speed" means, even after I mentioned 125 knots on the ocean, or have any knowledge of craft that displace less than 1,000 tons.

    I wasn't talking about 30 knot cats.

    I was talking about 150 knot cats.
     
  4. kach22i
    Joined: Feb 2005
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    kach22i Architect

    "High Speed" should be a specific standard, not one you just made up.

    I'm no expert, but any ferry faster than a slow one just might be considered fast, I'll guess over 20 knots and do some reseach on it. Sail craft would of course have a different standard.

    http://www.hornblowermarine.com/highspeed.html
    [​IMG]
     
  5. RatliffFranklin

    RatliffFranklin Previous Member

    A little deductive reasoning would have suggested <removed> that since I brought up the example of the Sea Dart I must have been talking about boats traveling in the same speed range.
     
  6. kach22i
    Joined: Feb 2005
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    kach22i Architect

    SAIL:
    http://www.answers.com/topic/catamaran
    FERRY:
    http://www.answers.com/topic/catamaran
    [​IMG]

    I think you may want to rephrase the topic to three point hydoplane to get to the speeds you are talking about, in that case, yes they do have wings..........to hold them down to the water and vertical stablizers.
    http://www.end.com/~jynx/travel/thunderboats/setup.html
    [​IMG]

    http://www.remote-control-rc-hobby.com/gas-powered-rc-boats.html
    [​IMG]
     
  7. RatliffFranklin

    RatliffFranklin Previous Member


    Didn't mean hydroplanes, <removed>.

    Said cats.
     
  8. kach22i
    Joined: Feb 2005
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    kach22i Architect

    You have a difficult time explaining what you mean. Perhaps you should learn to be more specific.

    http://www.nautica.it/info/tecnica/speed.htm
    If you meant to say "offshore racing the catamarans in Class I", then you should of said so. Otherwise you are just wasting time.

    Good luck with that attitude, say it to someones face - I dare you.
     
  9. kach22i
    Joined: Feb 2005
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    kach22i Architect

    Nope, nothing about class I racing cats, just an old jet fighter prototype.

    For the record, the Corvair Seadart:
    [​IMG]
    http://www.aerospaceweb.org/question/performance/q0190.shtml
     
  10. RatliffFranklin

    RatliffFranklin Previous Member


    <removed>

    Maybe the fact the Sea Dart had aerodynamic control surfaces was a big reason WHY it could run 120 knots on the open ocean decades before offshore boats were operating in the same speed range.

    You're a literal thinker.

    Find someone who understands analogy to explain it to you.
     
  11. kach22i
    Joined: Feb 2005
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    kach22i Architect

    It used a ski, why did you think it was a cat?

    Maybe a jet turbine getting the craft to take off speed had something to do with it's water speed. What do you think? Do you want to cruise at that stability level for long?

    Comp-1:
    http://www.seaphantom.com/trials.
    [​IMG]

    Comp-2:
    http://www.marinelog.com/DOCS/NEWSMMIII/MMIIIJun10.html
    [​IMG]
    [​IMG]

    The two comp's should not be taken as "literal".:cool:
     
  12. RatliffFranklin

    RatliffFranklin Previous Member

    Everytime I present anything for comment on this forum outside of what people ordinarily think of as boats, I either get zip/zilch/nada OR I get some <removed> who not only has no clue about the subject but is completely lacking in the good sense to know when to quit talking.

    http://www.americanjetcars.com/arfons/art/art64.htm

    http://www.americanjetcars.com/arfons/art/art61.htm

    Above are some links to a high speed cat that was to have used a wing as a control surface.
     
  13. kach22i
    Joined: Feb 2005
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    kach22i Architect

    Gosh darn, you are living my life.:D

    Stop doing that!
     
  14. RatliffFranklin

    RatliffFranklin Previous Member

    "Maybe a jet turbine getting the craft to take off speed had something to do with it's water speed. What do you think? Do you want to cruise at that stability level for long?"


    The domestic market for offshore powerboats capable of speeds over 100 mph is about 400 boats a year.
     

  15. kach22i
    Joined: Feb 2005
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    kach22i Architect

    That's good information, not sure where you got it from or what your point is.

    Let's say you don't want widows with lawyers sueing your boat building company, which design is safest for the beginner?

    I'm still not sure if we are talking ski's or cats. Here is an idea, sketch up your idea.........perhaps it will be a wonderful hybrid; air tunnel cat with retractable skis with self leveling spring action for stability in turns. Maybe just a monohull with canard fins for stability. Just something to give you that marketing edge of being different yet qualify for being part of that 400 boats a year.

    Give it a wack, I promise not to call you a *******, not for trying anyway.;)

    An idea of what I'm talking about:
    http://www.bugattiyachts.com/BugattiYachts/Advanced_Hulls.htm
     
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