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Thread: Price Outlook?

  1. #91
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    Default Re: Price Outlook?

    And now there are fins that work at anchor and cost a fraction of the gyro approach.

    I think a flat bottomed planing boat in any sort of sea is very uncomfortable.

    The problem with D and SD has been rolling but stabilisers have put pay to that problem.

    A flat bottomed planing boat in any decent sea at slow speed is not only unconfortable it is more dangerous than the D or SD in the same situation, although I accept that many a delivery skipper has had to bring a planing boat through some bad seas at slow speed, so I am only claiming a marginal difference in safety.

    The gradual move over to D and SD will in future be influenced by the price of fuel for the simple reason that fuel costs are set to rise and rise so slow speed boating will be preferred by more and the only way to do that in comfort is D or SD boats.
    Paul
    St Francis 50 Cat
    http://www.multihulls4us.com

  2. #92
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    Default Re: Price Outlook?

    The gyro cost is due to the current monopolistic situation.
    I can't see industrial reasons why it shouldn't be competitive costwise with the fins systems, in the near future (though I don't remember by heart for how long Mitsubishi granted Ferretti the exclusivity).
    Did you also look into other alternatives like http://www.quantumhydraulic.com/stab...s-maglift.html?

    Re. safety, yup, a marginal difference might exist, as long as people on board could get hurt being shaked around the boat, though in such conditions you'd better be careful on any boat...
    The only relevant difference would be in perfect storm conditions, where no planing boat would survive a capsize.
    But also between D/SD boats, just a very few of them are designed to self-right without structural damages after a capsize.

    And well, about the costs effect on the hull choice, as also Mike said, I guess we must agree to disagree on that...

  3. #93
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    Default Re: Price Outlook?

    Have a look at the ARG video http://www.ferretti-yachts.com/_vti_...builder.sphtml Seems to suggest that it works at slow speed but I guess your Italian is better than mine so you can tell us

  4. #94
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    Default Re: Price Outlook?

    [ QUOTE ]
    A flat bottomed planing boat in any decent sea at slow speed is not only unconfortable it is more dangerous than the D or SD in the same situation, although I accept that many a delivery skipper has had to bring a planing boat through some bad seas at slow speed, so I am only claiming a marginal difference in safety

    [/ QUOTE ]

    Wow, thats a sweeping generalisation. Not sure exactly what you mean by dangerous but let's for the moment assume you mean stability, and in particular, how far a boat can roll before it can't right itself. Have you got data that demonstrates that all SD boats have greater roll stability than all planing boats or is your definition of dangerous something else. I don't doubt for one minute that a Nordhavn has better roll stability than a typical planing boat but can you say the same about a typical floating SD Taiwanese tower block?
    Not sure what you mean be flat bottomed either? Do you mean the hull surface is flat or do you mean SD boats generally have a keel?

  5. #95
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    Default Re: Price Outlook?

    I looked at the video, and it frankly astonished me.
    First of all, not making an english version on a supposedly english web page is simply not up to the company they pretend to be.
    Besides, its contents are very poor, to say the least.
    They seem to rely much more on the images of boats and babes on the sunpad than on facts and figures...
    And the short parts where the boat behaviour with/without stabs is shown, that's not impressive at all.
    Aside from the drawings, the differences are almost unnoticeable.
    Yes, they say that the system is effective at slow speed, but there are no images showing/supporting that.
    They also stress as important points:
    1) the "invisible installation" (mind, not the fact that there is no drag due to exposed parts - which would make sense, particularly on fast boats - but just the aesthetic side...!);
    2) the silent operation (as if any other kind of stabs would be noisy, not to mention that you must keep the genny running, which surely can't be zero noise).
    Btw, the electrical requirements are amazing - I wasn't aware of that. I looked at a boat with a displacement similar to mine, and I should double my genny for the stabs alone!...

    Based just on this video, I'd rather put my money on good red wine than on such equipment.
    But of course a meaningful test could only be done onboard.
    I'd ask for the following, if I were interested in such boats:
    1) boat at anchor somewhere with constant cross sea (just 2' or 3' waves, but not another boat wave, which is useless) - stabs on and off;
    2) boat at hull speed or just above that (lower teens), also with cross sea, 8' waves or more - stabs on and off;
    If the differences in this second test are shocking, then the system is comparable to fins.
    Less than that, forget them for any use in rough stuff.

  6. #96
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    Default Re: Price Outlook?

    Mike
    "Have you got data that demonstrates that all SD boats have greater roll stability than all planing boats or is your definition of dangerous something else."
    I never said that all Sd boats - I generalised and yes on average the typical SD boat does have better stability and a lower CoG.

    "I don't doubt for one minute that a Nordhavn has better roll stability than a typical planing boat but can you say the same about a typical floating SD Taiwanese tower block?"
    I would agree that the Tiawanese tower blaock has reduced stability.

    "Not sure what you mean be flat bottomed either? Do you mean the hull surface is flat or do you mean SD boats generally have a keel? "

    They are a different shape and not so flat towards the stern as a planing boat.
    Paul
    St Francis 50 Cat
    http://www.multihulls4us.com

  7. #97
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    Default Re: Price Outlook?


    I'm confused. Several SD hulls I have seen, despite having a very fine entry with a very deep forefoot, have almost flat sections at the stern (but curved upwards towards the outer edges) whereas many planing hulls maintain 24' deadrise or thereabouts at the transom...

    dv.

  8. #98
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    Default Re: Price Outlook?

    Yup, I can see why you're getting confused.

    Firstly, those hulls which you describe remind of a pure D, round chine hull - not a SD hull.
    Full D hulls with hard chine (outer edges similar to a P hull) are even flatter.
    That's the flatter stern section hull which you can see around - no SD or P hull would ever be as flat as that.
    SD hulls typically are V-shaped at the transom, where they are more similar to a P rather than to a D hull.
    Their deadrise isn't necessarily deeper, if compared to a P hull, though.
    On average, I'd say that it's actually the other way round.

    See, overall, the boat stability depends on many other factors than the aft section shape alone.
    In fact, the most stable hull at D speed, which is obviously the D hull, is the one with the flatter stern!

    Did I further confuse the whole matter enough, for the moment?... [img]/forums/images/graemlins/grin.gif[/img]

  9. #99
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    Default Re: Price Outlook?

    Mmm, I thought you'd support your local manufacturer. Obviously not. I think it's safe to say that if a company like Mitsubishi made it and a company like the Ferretti group bought an exclusive licence, then the thing works. The concept of gyro controlled moving masses is well understood in the construction industry so I don't see why it won't work on a boat although I'd certainly want a demo first myself before buying it

  10. #100
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    Default Re: Price Outlook?

    [ QUOTE ]
    I never said that all Sd boats - I generalised and yes on average the typical SD boat does have better stability and a lower CoG.


    [/ QUOTE ]

    Go on, prove it because I don't think you can back that statement up

    [ QUOTE ]
    They are a different shape and not so flat towards the stern as a planing boat

    [/ QUOTE ]

    Quite the opposite usually. SD boats often have very flat stern sections to maximise lift to make them go as fast as possible within the constraints of the design. Planing boats usually maintain a good V angle right to the stern

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