Make your catamaran boat

Discussion in 'Multihulls' started by umut aras, Oct 28, 2017.

  1. umut aras
    Joined: Oct 2017
    Posts: 10
    Likes: 0, Points: 1
    Location: izmir

    umut aras Junior Member

    catamaran-production.jpg
    Catamaran boat design wit Cat 24 - 7,65m the full length of 4,55m width of a sailing boat. All manufacturing drawings is ready, the moment you want, you are able to manufacture. Manufacturing methods, such as plywood on epoxy resin with lamination method will be applied. Especially in the manufacturing itself is suitable for those who want to do a project. You can easily make your own catamaran boat. the project is suitable to build a boat with the plywood panel.


     
  2. Angélique
    Joined: Feb 2009
    Posts: 1,767
    Likes: 133, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    cat 24.jpg

    Hi Umut,

    What means of leeway resistance does the Cat 24 have ?

    Are the rudders retractable or foldable for draft limitation ?

    Are there any Cat 24 built yet ?

    Godspeed !
     
    Last edited: Nov 1, 2017
  3. umut aras
    Joined: Oct 2017
    Posts: 10
    Likes: 0, Points: 1
    Location: izmir

    umut aras Junior Member

    Hi Angelique,

    The boat will be a simple structure that can appeal to amateur users. So rudder isn't retractable or foldable.

    The boat is semi planing. If you can use up to 15kn leeway resistance is low.

    We haven't produced a boat yet.

    Regards,
     
  4. Angélique
    Joined: Feb 2009
    Posts: 1,767
    Likes: 133, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Hi Umut, thanks for the info !

    Maybe give her some simple LAR keels at the same depth of the rudders, she'll be a bit slower then because of the added wetted surface, but it'll also enhance her windward ability a lot I think. And she'll be able to dry out level on the LAR keels, without the stern raised by fully standing on the rudders, which in the rendered set up looks to me like making drying out impossible at all for constructive reasons.

    P.S. - - Here's an LAR keels example, plus a video / source.

    LAR keels and fixed spades rudders on a modified Dazcat 9.2 dried out on Erquy Beach.jpg

    LAR keels and fixed spades rudders on a modified Dazcat 9.2.jpg
    LAR keels and fixed height spades rudders on a modified Dazcat 9.2

    Good luck !
     
    Last edited: Nov 2, 2017
  5. umut aras
    Joined: Oct 2017
    Posts: 10
    Likes: 0, Points: 1
    Location: izmir

    umut aras Junior Member

    Hi Angelique,

    Thank you for your good informations. I will consider what you say.

    Regards,
     
  6. pogo
    Joined: Mar 2010
    Posts: 338
    Likes: 8, Points: 18, Legacy Rep: 73
    Location: Germany Northsea

    pogo ingenious dilletante

    Mmmh...

    pogo
     
  7. DGreenwood
    Joined: Aug 2004
    Posts: 711
    Likes: 34, Points: 28, Legacy Rep: 507
    Location: New York

    DGreenwood Senior Member

    And your history in designing successful catamarans is......?
     
  8. Burger
    Joined: Sep 2017
    Posts: 4
    Likes: 0, Points: 1
    Location: Australia

    Burger New Member

    A 24' ply/epoxy cat rigged as shown will cost a minimum of $35K and around 12 months work. A big investment to make on the strength of seeing a few computer pictures from someone unknown on the internet.

    Nice pictures though.

    The statement about not needing keels/boards because the boat is expected to plane at 15 knots is a bit of a giveaway.
     
    Last edited: Nov 2, 2017
  9. Angélique
    Joined: Feb 2009
    Posts: 1,767
    Likes: 133, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    We could have a language problem here, as it's not easy to know all the jargon terms in foreign languages.

    Forum mate Charly aka Charlyipad has some scans from a sailing book for guests on his website, and these pictures might clarify the used terms here.

    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    Charly's boat - Logbook: The Spirit of St Simons - St Simons Island Sailing Charters

    Basic Sailing: - Lesson One - | - Lesson Two* - | - Lesson Three - | - Lesson Four - | - the pics there are clickable for enlargement

    * - Note ‘‘Lateral Resistance’’ there is what I've called ‘‘Leeway Resistance’’ in the above.

    Lateral Resistance (aka Leeway Resistance) is provided by to the hull added keels and/or boards, together with the lateral plane of the hull, or depending on the hull form sometimes solely by the lateral plane of the hull. CLR = Center of Lateral Resistance.

    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    From lesson one: - - - - - - ( here's a bit bigger pic, so the sailing directions names and angles are a bit better readable )
    sailing directions names.jpg

    By the above ‘‘enhancing her windward ability’’ I've meant reducing the dark shaded wedge where the boat can't sail against the wind at the top of the pictured sailing directions circle.

    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    From lesson two:
    sailing to windward forces.jpg

    Note the here pictured boat is ‘‘close hauled’’, aka ‘‘moving to windward’’, aka ‘‘going to weather’’, in this case at the top right position in the first picture, just at the right of the dark shaded wedge in which the boat can't sail against the wind.

    The ‘‘Leeward Component of Force’’ is what needs to be countered by the ‘‘Lateral Resistance Force’’ (aka Leeway Resistance) as much as reasonably possible, otherwise the boat makes to much leeway = moving sideways to lee, which as well could be a lee shore.

    Good luck !
     
    Last edited: Nov 3, 2017
  10. umut aras
    Joined: Oct 2017
    Posts: 10
    Likes: 0, Points: 1
    Location: izmir

    umut aras Junior Member

  11. Angélique
    Joined: Feb 2009
    Posts: 1,767
    Likes: 133, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    For this best rent a daggerboard catamaran, pull up the boards, and see in what directions you can sail.

    Good luck !
     
  12. Angélique
    Joined: Feb 2009
    Posts: 1,767
    Likes: 133, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    This can be compared with the directions that can be sailed with the leeward daggerboard down, and then a judgement can be made how important the leeway resistance provided by the board is to you.

    Good luck !
     
  13. redreuben
    Joined: Jan 2009
    Posts: 1,500
    Likes: 34, Points: 48, Legacy Rep: 349
    Location: Beaconsfield Western Australia

    redreuben redreuben

    Vapourware
     
  14. Angélique
    Joined: Feb 2009
    Posts: 1,767
    Likes: 133, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Yes, that's my impression too, but just in case the plans ever hit the market better encourage to give it some serious thoughts.

    And this also brings the ‘‘know-how’’ of the design team to light for potential plan buyers.

    So I'll move on with my serious conversations about this topic . . . ;)
     
    Last edited: Nov 14, 2017

  15. Angélique
    Joined: Feb 2009
    Posts: 1,767
    Likes: 133, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    BTW, about the Cat 24 . . . .

    Overall Length: 7.65 m = 25' 1 3/16" = 25.1' - *
    Hull Length: 7.55 m = 24' 9 1/4" = 24.77' - *
    Length of Water Line: 7.52 m = 24' 8 1/16" = 24.67'

    Maybe better call it Cat 25 . . . . ?

    * In the renders I don't see anything sticking out of the stem or stern, so what's the 9 cm (3 35/64") that the Overall Length is longer than the Hull Length ?

    Good luck !
     
    Last edited: Nov 14, 2017
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.