How to decrease the inclining oscillation and increase the stability on the boat

Discussion in 'Stability' started by Nickname123, May 30, 2017.

  1. Ad Hoc
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    Ad Hoc Naval Architect

    Only if you do not know what a GZ curve is, nor, what influences it!
     
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  2. Mr Efficiency
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    Mr Efficiency Senior Member

    The deep-vee hull is, in itself, of course, not an impediment to ultimate stability taking into account fixed weights, but the substantial non-fixed weights aka "people" are likely to have a very detrimental effect on stability such a narrow, initially very tippy vessel, in rough water, why would a deep-vee be selected, unless rough water use was anticipated ? Mr Ad Hoc, would you board this vessel after inspecting the visuals and lines drawings ? I'd say not.
     
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  3. Ad Hoc
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    Ad Hoc Naval Architect

    Just showing your ignorance on the technicalities of design again.

    A GZ curve will immediately highlight if there is an issue. Since placing the moment, that being the weight of person(s) by the level from the CL to their outboard location, on to the GZ curve will tell you at what angle of list will the vessel adopt.

    Simple....well to naval architects it is. But not to armchair designers...

    Naval architects/Engineers use and deal with facts....not supposition and guess work to arrive at answers/solutions.
     
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  4. Mr Efficiency
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    Mr Efficiency Senior Member

    We don't know how many persons of course, or even if they are over-fed tourists, but Blind Freddy can see it is very precarious at best. Chine to chine.....barely 5 feet.
     
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  5. Ad Hoc
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    Ad Hoc Naval Architect

    Oh hang on, then you say:


    So which is it...you know or you don't know? Can't have it both ways Mr Flip-Flop
     
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  6. Mr Efficiency
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    Mr Efficiency Senior Member

    No flip-flopping here, I assume the worst scenario of as many as a dozen or more people.....western tourists.....that boat is dangerous, anyone familiar with small craft like this will know it.
     
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  7. Ad Hoc
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    Ad Hoc Naval Architect

    Exactly...an assumption based upon no evidence and no facts....just as noted above, re: armchair designers. yet you continue to state:

    Oh the irony!

    About as helpful and useful as a fart in a space suit.
     
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  8. Mr Efficiency
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    Mr Efficiency Senior Member

    Take a look at the cabin, a dozen people could easily fit in there......I assume, not unreasonably imo, that that space will be used. Otherwise, why build it to those dimensions. The OP can fill in the detail if/when he returns.
     
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  9. Ad Hoc
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    Ad Hoc Naval Architect

    So...in other words, you haven't a clue as yet there are no facts, however, you like to offer opinions based upon no facts. And then when highlighted, oh..., let's wait for more info from the OP. o_O
     
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  10. Mr Efficiency
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    Mr Efficiency Senior Member

    The only hope is to turn it into an RIB, imo. Easier said than done.
     
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  11. TANSL
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    TANSL Senior Member

    No, I do not come from that school, which you seem to know well. I like to be rigorous in my comments, although sometimes I am wrong.
    The facts, not the assumptions, are that the GZ curve, which serves many things, does not serve to determine the initial GMt. That's the only thing I say. If you think that I have said something else, you will be in the field of assumptions, which you seem so much to despise.
    I think that other options could be tried before saying that this is the only hope, without having made a single number (yes, I suppose it was a joke).
     
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  12. Ad Hoc
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    Ad Hoc Naval Architect

    I dont have to assume you know nothing of which you write. Well, rather than use words, a picture says it all:

    Typ GZ curve.jpg
     
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  13. Mr Efficiency
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    Mr Efficiency Senior Member

    I suggest Ad Hoc well knows the GZ curve won't be forthcoming, what may be forthcoming is the cry of "beGeeZus" if this thing goes awry with unwitting passengers on board.
     
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  14. Jed233
    Joined: May 2017
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    Jed233 Junior Member

    Is there a formula to determine if it is possible and what the power requirements are to push a hull through it's mathematical 'hull speed' without going to plane?
     
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  15. TANSL
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    TANSL Senior Member

    Ad Hoc, thank you for such a beautiful picture.
    The facts, not the assumptions, are as follows : to plot the tangent at the origin of the GZ curve, you need to have previously calculated the initial GMt. The GZ curve can not be drawn, in the coordinate origin area, without knowing the initial GMt but to know the initial GMt you does not need at all the GZ curve.
    I never thought I'd have to explain this to you, but I'm glad to. Cheers.
     
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