When is a mono a tri?

Discussion in 'Multihulls' started by Lurch723, Jan 2, 2017.

  1. Lurch723
    Joined: Aug 2012
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    Lurch723 Junior Member

    Over the last couple of years in my spare time I have been building a boat I designed. I was looking at the aging skiff sailor problem and how to solve it.

    So I designed a thin main hull (possibly foil assist) with a couple of outriggers for static roll stability, plus it has the advantage of reducing the over to windward effect when two crew are out on the wire and your apparent wind drops.

    So we have what is ostensibly a mono with stabilisers, would this still classify as a mono or would it be a trimaran?
     
  2. Doug Lord
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    Doug Lord Flight Ready

    I think if it has three hulls it's a tri regardless of how the amas are used.
    An example that may be somewhat similar to your boat is the F101 trimaran foiler.

    http://www.boatdesign.net/forums/multihulls/new-trimaran-foilers-55834-5.html post 66

    click-- The picture to the right is the Tantra, a monohull with molded in "leeboards" though some wanted to call it a trimaran....
    The green boat was designed as a monohull with small outriggers but was surely a tri even though they didn't actually sail on the little amas*:
    *and since it didn't sail like a trimaran the point could be argued.
     

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  3. PAR
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    PAR Yacht Designer/Builder

    Agreed, attachment isn't a portion of the hull forms description. What were the foil shapes you used on that mono?
     
  4. Doug Lord
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    Doug Lord Flight Ready

    Tantra

    Paul, it was an asymmetrical section with replacaeble tips-don't remember the specific section but they worked well. The boat was about equal with a US1 up and down even though it was 100lbs heavier using the same rig.
     

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  5. Angélique
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    Angélique aka Angel (only by name)

  6. Lurch723
    Joined: Aug 2012
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    Lurch723 Junior Member

    Well I didn't want to crash another thread and thought this was a good way of establishing an indipendant opinion on a configuration. But I guess 3 hulls are three hulls regardless of the intended purpose of the outriggers in relation to the main hull.

    So essentially it's a tri and I had better get used to calling it one. I've attached a piccie of it de-rigged without the small displacement hulls.

    My foil configurations are (to start with) a normal daggerboard and a rudder with an elliptical lifting crucifix foil. The next configuration will be a third foil that is deployed just in front of the daggerboard which will deliver enough lift to make the boat breech at about 22knots. Then next season I will build a fully foiling configuration, but I stress it was never my intention to go fully foiling but instead to explore the benifits of foil assist configurations.
     

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  7. Doug Lord
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    Doug Lord Flight Ready

    It would be great to see a picture of the boat fully assembled and sailing-looks good.
     

  8. Lurch723
    Joined: Aug 2012
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    Lurch723 Junior Member

    I will post some pics of it after I launch it in April and get the first nerve wrecking trial sails out the way. Lots to do until then...
     
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