Estimated Block Coefficient for Catamaran Vessel

Discussion in 'Boat Design' started by 07MAM, Aug 7, 2018.

  1. 07MAM
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    07MAM Junior Member

    Is there anyone can refer me a Cb for Catamaran Ferry. Just for estimation or a standard one if there is a standard Cb for Catamaran Vessel.

    Details:
    LOA 100FT
    TYPE Passenger Vessel with 3 deck on top

    Thank you in advance for opinions and suggestion
     
  2. bit
    Joined: Feb 2008
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    bit Student

    Approx 0.42
     
  3. TANSL
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    TANSL Senior Member

    Is Cb the block coefficiente?. In addition to the number of decks, we would have to introduce some other variable in the formula that, if it existed, would allow us to deduce an appropriate block coefficient for your boat. But, as far as I know, answering your question, there is no standard value for 3-deck passage catamarans.

    P.S. Deleted a comment for being consequence of an incorrect interpretation of the question.
     
    Last edited: Aug 8, 2018
  4. 07MAM
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    07MAM Junior Member

    Thank you for all your inputs. Well appreciated.
     
  5. rxcomposite
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    rxcomposite Senior Member

    Designed operational speed?
     
  6. 07MAM
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    07MAM Junior Member

    20 knots sir
     
  7. rxcomposite
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    rxcomposite Senior Member

    Is this a student thesis project or a design estimate? We need to know so we can tailor our response to you.
     
  8. 07MAM
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    07MAM Junior Member

    Design Estimate sir
     
  9. BlueBell
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    BlueBell Ahhhhh...

    "Sir", that's rather presumptuous of you isn't it?

    How many passengers?
    Cars?
    Seas?
    Travel distance.
    Seasons.
     
  10. 07MAM
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    07MAM Junior Member

    100 passenger
    no car
    Davao Gulf
    47.27km
    No season.
     
  11. rxcomposite
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    rxcomposite Senior Member

    You are outside the range. To realize that you need a 300 ft hull. for 20 knots you are designing around a very slim hull, NPL type, destroyer type, overdriven, with poor fuel economy.
     

    Attached Files:

  12. Mr Efficiency
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    Mr Efficiency Senior Member

    He is talking catamarans, plenty of them 100 feet long doing 20 knots.
     
  13. rxcomposite
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    rxcomposite Senior Member

    The table is not limited to mono. Just speed to length ratios or Froude number. Resistance and powering formulas will analyze the efficiency of the hull.
     
  14. Mr Efficiency
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    Mr Efficiency Senior Member

    So what range is he out of ?
     

  15. 07MAM
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    07MAM Junior Member

    100ft hull only. Based on the presentation sir the sample ratios that I can used is ranging form 0.67-0.73. Well noted of this sir. Thank you so much
     
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