Ques. Increasing sail on Finnsailer?

Discussion in 'Stability' started by welder/fitter, Apr 16, 2009.

  1. welder/fitter
    Joined: Jun 2008
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    welder/fitter Senior Member

    A friend of mine has just bought, or is planning on buying - not sure which he said - a Finnsailer35. He said that he was planning on increasing the sail area from it's present 360sq.ft., by increasing mast hgt. & moving the forestay further forward. Isn't that something that he should have a designer look at? I looked up info on the Finnsailer & it seemed pretty lightweight. I'd assume that he'd be making it pretty tender if he doesn't correspondingly increase ballest, as low as possible. Interested in opinions on this, as I'd hate to see him testing his righting moment the hard way.
  2. terhohalme
    Joined: Jun 2003
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    Location: Kotka, Finland

    terhohalme BEng Boat Technology

    Increasing the ballast (and righting moment) can lead to rig failure. Finnsailer is quite a pure motorsailer, very little to do about making her faster. Sorry.
  3. welder/fitter
    Joined: Jun 2008
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    welder/fitter Senior Member

    Thanks, that's pretty much what I figured. I hate to be the bearer of bad news, but I'd hate to see my buddy become a statistic. As he will only be using the boat for local weekend/holiday trips, I'm sure that it'll serve his purposes, as is.

  4. Guillermo
    Joined: Mar 2005
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    Guillermo Ingeniero Naval

    Finnsailer 29 has a SA/D ratio of 9.36 and a D/L ratio of 249.

    I wouldn't say it's totally impossible to increase sail area to a certain extent, as it was done with Banjers bringing up their SA/D ratio from less than 8 to around 14, improving performance in light airs dramatically. Banjers were originally conceived as heavy motorsailers with a distinct emphasis on the motoring side of the job. Quality of movements also improved quite a bit with the taller rig. Not a bad move, followed by many Banjer owners with the original smaller rigs.

    Of course the full rig has to be redesigned, as well as ballast, but perhaps is doable. If it makes economical sense, that's another question.


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