Power-Cat. concept design

Discussion in 'Boat Design' started by Lee01, Jun 27, 2017.

  1. Lee01
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    Lee01 Junior Member

    Ciao, here is the video of a recent concept for a cruising multihull with a planing hull, the name is Mambo, let me know your comments ;)

    Thanks to the forum and to the Designers that publish many information here!
    Camillo
     
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  2. Mr Efficiency
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    Mr Efficiency Senior Member

    46 tons and 49 knots ? Seems optimistic.
     
  3. jorgepease
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    jorgepease Senior Member

    Beautiful boat and nice video, I don't think the torqeedos are suitable.
     
  4. TANSL
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    TANSL Senior Member

    As there is no technical data on the ship, nothing can be said about it as a floating element, on the fulfillment of its SOR, on the comfort and safety of the passage. Therefore, opinions will only be, I suppose, with regard to the look of the boat. That is, we can have opinions on how beautiful or ugly we think rendering, but not on the boat. However, I will make some very general comments.
    - Ship's scantlings are, apparently, according to ISO 12215-7, which has not yet come into force ¿??.
    - why put the LOA slightly lower than 24 m when the LH requesting the ISO standard can, and usually, be somewhat smaller than the LOA ?.
    - The anchor housing on the side is very low. The sea will hit a lot on the anchor.
    - The windmills are precisely in the best area of the boat for sunbathing.
    - Little space on deck for the passage. A catamaran should have much more space.
    - The auxiliary boat can not remain hanging from the davit when the boat sails. You have to seat it on deck, further reducing the space for the passage.
    - The superstructure looks like a very large enclosure. Without a doubt it will have a powerful air conditioning, otherwise, it can be an overwhelming space.
    - Putting the boat at 49 knots can be a very unpleasant experience for the passage. Although I can not state this categorically, it is possible that this makes it necessary to classify the boat as "High Speed Craft" with everything that, as far as regulations to comply, means.
    In short: nice object. Good boat? I do not know.
     
  5. Lee01
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    Lee01 Junior Member

    Unlike usual displacing power-cat this should be an extreme yacht, and at this stage of the design I am happy if it looks nice and has some chance to float. Thanks jorgepease I don't know if the gyroscopic stabilizers are suitable and why. Tansl, the hull has no overhangs and I think that the Loa will be the same as the Lh, and I don't like bolted bows because I have read that they become visible under the gelcoat. I ignored that 12215-7 is not in use, thanks, and I'll discover what you mean for windmills, passageways are around 3 ft. in width to save room inside. Since none noted the wide-body belowdeck, if not impossible I think it would need some study for scantling and the structures. I suppose that a powerful Ac and a generator would be present onboard, especially after disembarking the Torqeedo :)
     
  6. TANSL
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    TANSL Senior Member

    I do not know what you mean with bolted bows.
    What I can foresee is that the anchor hits on the niche can be worrying.
    Not only is it not in force, but they have circulated a couple of drafts that differ markedly from each other. Using them, therefore, can be dangerous.
    The video shows that the hull has been calculated according to ISO 12215-7. Apparently it has not yet been calculated in any way.
    I suppose you will need more than one generator on board.
    I think it would be good to do some calculations of hydrostatics and stability before presenting the boat to the public. It is very important, in the early stages of design, to also make a detailed calculation of weights and their centers of gravity. At least to check that the boat is floating properly.
    By the way, LOA is clearly greater, and rather, than LH
    Mambo.jpg
     
    Last edited: Jun 27, 2017
  7. JSL
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    JSL Senior Member

    clearance between hulls looks a bit small. Could be some excessive resistance
     
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  8. Mr Efficiency
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    Mr Efficiency Senior Member

    Won't be a problem at the cruise speeds being envisaged, I'd say.
     
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  9. Lee01
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    Lee01 Junior Member

    and also asymmetric hulls produce less divergent waves to the inside than to the outside. Here anchors are in another point on the bow

    2s.jpg
     
  10. TANSL
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    TANSL Senior Member

    Two anchors, in that position, can cause difficulties and are not very operative. Preferably place only one, in the center line.
    Radars, too low, are a danger to passengers: radiation.
    Have you forgotten the rescue boat? You'll need the davits that can be seen in the video, or something similar.
    The cabin looks more like a patrol boat than a pleasure boat, but this is an opinion and therefore subjective.
    I agree with the view that hulls, so close together, can reduce hydrodynamic performance, especially in the preplanning phase of the boat .
     
  11. Alik
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    Alik Senior Member

    At the moment, it is just a picture, not a concept. Concept should at least include weight estimate, performance prediction and some sort of stability analysis.
    There 100 plus one issues I can see on this cat, starting from bottom strakes at stern not compartible for jet drives, to wrong proportions of the hull/tunnel...
     
  12. Lee01
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    Lee01 Junior Member

    I like the look of a patrol boat or HSC for a planing multihull yacht. Only bare hull resistance and effective power prediction was carried out, the tunnel widhth is 1/3 of Bc. The weight estimate is heavy and I wish that there would be some margin. I have noticed spray strakes on water jets extend up to the transom but I haven't found why if this is one problem
     
  13. TANSL
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    TANSL Senior Member

    Nothing is a problem or stop being it, especially in a so initial stage of what in its day can become the design of a catamaran.
     
  14. DCockey
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    DCockey Senior Member

    What are the estimates of displacement and speed based on?
     

  15. Lee01
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    Lee01 Junior Member

    Rhino 3D platform for displacement and resistance with prop curves and specifications. I am in search for a reliable builder to make progress, on even more traditional projects so I think it will need a lot of time!
     
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