Lifting Strake Width

Discussion in 'Boat Design' started by Lewis14Lewis, Sep 5, 2019.

  1. Lewis14Lewis
    Joined: Sep 2019
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    Lewis14Lewis New Member

    Hello,

    I am currently designing a 100' planing craft with a deep V. I have defined the chine and am currently looking to put lifting strakes on the vessel.
    I am fine in terms of arrangment but I can't find any information on how wide the strake should be (to produce enough lift) for a roughly 130 tonne vessel.
    Are there any calculations or graphs I can use?

    Thanks,

    Lewis
     
  2. JSL
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    JSL Senior Member

    what is your cruising & max speed???
     
  3. Mr Efficiency
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    Mr Efficiency Senior Member

    The "lift" will be largely hydrostatic in a 130 ton 100' boat unless it is jet propelled. And I don't mean water-jet !
     
  4. Lewis14Lewis
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    Lewis14Lewis New Member

    28 knots maximum speed and cruising is 22 knots
     
  5. JSL
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    JSL Senior Member

    Assuming the LWL is about 90', these speeds are not good for a deep V planing hull form: your speed/length ratios are 2.9 and 2.3 respectively... way below minimum planing speed. You should be looking at a more suitable hull form like a semi displacement/semi-planing. All the strakes will do at your speeds will be to increase resistance, fuel consumption, maintenance, costs, etc).
    - posting a drawing or sketch of the "Hull Lines" might help everybody involved
     
    Last edited: Sep 6, 2019
    fallguy likes this.
  6. rxcomposite
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    rxcomposite Senior Member

    Savitsky will work. This strake is part of projected area of the planing hull. This strake should not be taken in isolation.

    I remember there is an Excel spreadsheet posted here in the forum by Dingo. This should aid you in the calculation.
     

  7. Mr Efficiency
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    Mr Efficiency Senior Member

    More a case of a device to stop water climbing up, on the forward part of the bottom, with such a boat.
     
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