design for light airs

Discussion in 'Sailboats' started by hiracer, Jun 14, 2006.

  1. Guillermo
    Joined: Mar 2005
    Posts: 3,644
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    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    With those data and guessing a hull draught of 2' 5" and 34 HP engine power (please correct otherwise):

    Ballast/Disp Ratio W/Disp = 0,34
    Displacement/Length Ratio D/L = 291,81
    Sail Area/Disp. Ratio SA/D = 15,87
    Power/ Disp. Ratio HP/D = 1,88 HP/ton
    Hull speed HSPD = 7,37 Kn
    Potential Maximum Speed PMS = 7,84 Kn
    Velocity Ratio VR = 1,06
    Comfort Safety Factor CSF = 1,71
    Motion Comfort Ratio MCR = 34,78
    Screening Stability Value SSV = 38,56
    Angle of Vanishing Stability AVS = 124 ยบ
    Heft Ratio HF = 1,25
    Roll Period T = 3,41 Sec
    Roll Acceleration Acc = 0,08 G's
    Stability Index SI = 1

    Pretty nice figures.
    If you provide the Heeeling Arm, I'll calculate the Dellenbaugh angle for you, and other indicative stability data.
     
  2. hiracer
    Joined: Jun 2006
    Posts: 158
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    Location: Puget Sound, Washington, USA

    hiracer Senior Member

    Thanks for your interest. I don't have the heeling arm unfortunately.

    She sailed well during the test sail. Totally different from my last boat (which was a racer-cruiser). I've never sailed a "heavy" displacement boat. I don't think I'll ever go back to medium or light displacement. The motion was soooooo pleasant. Yet she sailed well enough too. What an enlightment for me.

    We sail in 9 - 10 knots of wind per instruments, which actually seems a bit high by my estimate of 6 - 10 knots of wind. She tacked somewhere between 90 and 100 degrees. Didn't pay enough attention to this. Was having way too much fun. There was about 1.5 knot of current that we sailed with on the way back to the marina, so presumably the speeds to the windward were better than I realised because we were working against a current. Plus, we sailed her as a sloop. So, I don't even know how well she sails, yet. But certainly I'm happy with her.

    She ain't no racer. She does heel easier than my last boat--but only to a point, then she hardens up. My old boat had a B/D ratio of .41 and was beamier relative to LWL, so this would be expected. But she isn't a dog. She sails beautifully. Balance, steady helm, and we were gaining on the other boats in front of us. Better than average sailer; yet a full blown cruiser.

    We will be closing ASAP. I found my baby.
     
  3. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 189, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    Congratulations! Enjoy her!
     

  4. cburgess
    Joined: Aug 2006
    Posts: 10
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    Location: NW Florida USA

    cburgess Junior Member

    Thanks Guillermo.

    I found your site interesting, even though I don't read spanish (I used one of those online page translators). My ear does better with spanish than my eyes do. Your english is excellent.

    Schooners - can carry more sail to catch more air, without needing a large crew. A traditional keel is a must for stability. And wood makes maintenance and repairs easier for the individual owner. A single person can handle a 30 to 40 foot schooner without any problems...a second crewmember is of course always welcome and make sailing more enjoyable.
     
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