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Quantum Stabilizers

Discussion in 'Stabs, Tabs & Gyros' started by 84far, Aug 21, 2011.

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  1. 84far

    84far Senior Member

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    Hi,

    I was just wondering if anyone has had any experience with Quantum Stabilizers as opposed to the more traditional stabilizers. There seems to be a reduction in drag (less surface area), and it seems to do a better job in general...?

    Far
  2. corinthian99

    corinthian99 New Member

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    Yes, well there's a fair few of us who have used Quantum a lot. Not quite sure what you mean by traditional stabs - are you referring to non-zero speed units? Used Naiad units as well. What do you want to know?
  3. 84far

    84far Senior Member

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    Hi,

    I'm talking about the Mag Lift Zero Speed Rotary Yacht Stabilizers, which is a cylinder like object that spins around (for those that don’t know). As opposed to the “standard” fin stabilizers.

    Basically wondering is it just a bit of a fad and works the same, or should I start thinking all boats will head in this direction in the near future, as the fins will be faded out of the market. I’m now also aware they have been around for a few years...?



    Far
  4. C4ENG

    C4ENG Senior Member

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    I have seen very few of those Mag Lift Zero Speed Rotary Yacht Stabilizers on vessels in the ship yards in S FL. The vessels I have seen with that system where in the 70ft range. I have not seen or heard of any 150's+ with that system.
    I would like to know more myself about that system.
  5. 84far

    84far Senior Member

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    Hi C4ENG, I'm at the moment sizing up a 35m and I was curious to what size stabilizers I needed for the vessel. I jumped on a particular website and found these Mag Lifts... I didn't realize that these existed until yesterday morning.

    I have a feeling these are like comparing Pod Unit compulsion against the Shaft.

    Doesn’t look like there’s too many boats running this system though.:rolleyes:

    Far
  6. paolo_ita

    paolo_ita New Member

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  7. C4ENG

    C4ENG Senior Member

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    Paolo seemed to answer a few questions there for sure. As I was looking through those links, I started to think of pros and cons between the conventional fin stab and the Maglift. I would have to imagine the Mag lift would consume much less power than the conventional fin set. Then you can have smaller gens saving fuel and additional weight and space.
    I would like to hear from some one with real world experience on the Maglift, good, bad, ugly?
  8. 84far

    84far Senior Member

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    paolo_ita, thanks for the links, the youtube clips look very good. I wouldn't mind seeing the video showing the boat with the mag lift and one with conventional fin stabilizers... that would make things interesting.

    I guess it's more to do with the other aspects of the systems that one can not really see.

    As for the good, the bad and the ugly, it might be a little to soon.

    Far
  9. 84far

    84far Senior Member

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    Another thought... this new Mag lift system... will that also do a similar job as a gyro...? I've been reading up on the gyro vs fins, it seems the gyro will do a better job when the boat is at anchor, but the fins show better performance when the vessel is moving...?

    Just wondering is the Mag Lift doing both of these jobs...? Thoughts...?

    Far
  10. 'RoundTheHorn

    'RoundTheHorn Senior Member

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    Yes, they are supposed to work at low speeds and at anchor.

    http://www.quantumhydraulic.com/pages/stabilizers-maglift.php
  11. Innomare

    Innomare Senior Member

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    The biggest advantage of the rotors is that they're retractable:
    They can be quite long (and thus efficient) without risking contact with the pier, as they would be retracted when mooring.

    On cruise ships, the stabilizing fins retract automatically at speeds below 3 knots, but I guess the captain on a MY with maglift rotors will have to be smarter, or there's not going to be zero-speed stablization.

    The gyro's have the advantage of also being effective for boats with very short natural roll periods (typically very light, hard chine boats). This can be more problematic for the hydraulic systems which can't react so fast, but I don't know how the maglift rotors score in this respect.


    Bruno
  12. BMcF

    BMcF Senior Member

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    This is true...as far as it goes.;) The magnus effect rotor system operates in a "sweeping" mode at zero speed and "rotation reversal mode/not sweeping" when the vessel has way on. So, in effect, the velocity of water required to be passing over the rotor(s) when the vessel is lying still is created by the sweeping motion of the rotor(s) themselves.

    Pretty sure that there is as video clip on the QME site someone linked to in an earlier post that shows the system working - and basically how it works -in a 3D animation.
  13. 84far

    84far Senior Member

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    Yes, there's one of Eclipse, and I was surprised that they could get such good results from that Eclipse model. I know as far as test models go it was a big model, but the discrepancy between the model and the real thing would of been on the back of the everyones minds.

    A few people have mentioned you would want to retract the Maglift when docking. I was thinking could they be installed so there still within the silhouet of the vessel...? Sometimes these big girls, not just Eclipse, have to dock in more open water than tucked up in a corner...?

    Far
  14. BMcF

    BMcF Senior Member

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    You speak of "the discrepancy" as if it is a natural outcome or foregone conclusion of model testing. I vigorously beg to differ.

    Can a model test be throroughly mucked up and/or the results improperly interpreted? You bet. Keeps lawyers quite busy when "M/V Rocket Sled" misses her speed target by 10 knots. (apologies if there is any resemblance of that fictitous example to a real vessel by that name.:cool: )

    But there are very solid and reputable model testing facilities scattered about the world that can repetitively produce very reliable results. Designers and product manufacturers tend to use those facilities when they can.;)
  15. BMcF

    BMcF Senior Member

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    That simply refers to the fact that with most installations, the rotors will extend beyond the deck or rub rail edge when deployed. The same holds true for some fin stabilizer configurations that are retractable, although those seem to be comning increasingly rare.
  16. 'RoundTheHorn

    'RoundTheHorn Senior Member

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    Rolls Royce manufactures a couple of retractible models, but I had heard that that they are VERY expensive - the Aquarius and Neptune models. It looks as if the Aquarius model can also set up for at-anchor use as well.

    http://www.rolls-royce.com/marine/products/stabilisation_manoeuvring/stabilisers/index.jsp
  17. BMcF

    BMcF Senior Member

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    [QUOTE='roundthehorn] It looks as if the Aquarius model can also set up for at-anchor use as well. ][/QUOTE]


    I hadn't seen that before advertised from RR. I notice that feature is only available on the larger models in the product range.

    I would be interested in seeing any information, anecdotal or otherwise, as to how well an actual installation of that RR package is working at rest. At-anchor stabilization is becoming more and more common so I guess it stands to reason that RR wasn't going to sit and watch from the sidelines.

    In general terms, at-anchor stabilization using fins is "hard on the hardware". First, simply because its typically used for so many more running hours than underway stabilization is, and secondly, because the at-anchor control alorithm involves thousands of high-rate "bang-bang" max-rate fin motion cycles over the full angular range, something almost never seen during routine underway where 'mostly linear' control is being employed. Thus its often the case that a fin manufacturer's at-anchor hardware will be more robustly designed and sized than for a conventional underway-only application.

    I'm probably drifting a bit far afield from thread topic....sorry about that. I've dabbled in the field a bit.;)
  18. oceaneer

    oceaneer Member

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    RR Fins

    We were anchored next to one of the big oceanco's with the on anchor retractable stabilizers. It was not pretty at all. Huge acceleration and very little dampening of the swell.
    The system may have been not working correctly, if it was then its not so good.

    Oceaneer
  19. 84far

    84far Senior Member

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    The discrepancy statement was more of rhetorical statement, but is an issue forsure, and even more so for (hydro) dynamic application such as stabilizers. Sometimes scaling down/up may bring different results than first thought - I'm into the F1 racing, and love the technical aspect of the whole thing, and the amount of times a team get different/wrong results from the wind tunnel to the track is not rare. I was even reading about one team incorrectly scaling exhaust temps.

    As for M/Y Rocket Sled - having a father as a lawyer does have it's pros :rolleyes: .

    Your definitely right in regards to the model testing facilites, even though they do cost an arm and a leg do obviously answer questions, and compaired to the overall costs of the boat is really just a small proportion.

    Far
  20. 84far

    84far Senior Member

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    It's funny you should say that, I believe it was Kevin or YachtNews was saying he saw Eclipse was having a good roll... yet again, they could of had there system turned off, or other reasons..?

    Far