Click for Abeking Click for Nordhavn Click for Walker Click for Fendertex Click for Llebroc

Quantum Stabilizers

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

You need to be registered and signed in to view this content.
  1. 84far

    84far Senior Member

    Joined:
    Dec 15, 2008
    Messages:
    833
    Location:
    Brisbane, AUS
    Yes, I realise this, but why not design the Stabs so they can be used when an object is in close quarters... like a dock? If a boat is docked in a busy river and getting plenty of swell off the traffic, they could go into action taking pressure off the mooring lines fenders etc. Just a thought.

    Far
  2. oceaneer

    oceaneer Member

    Joined:
    Jan 6, 2008
    Messages:
    55
    Location:
    Victoria BC
    Allot of boats use the stabilizers when at dock, we do all the time. In some areas you need them on as the swell will have you knocking your topsides against your neighbors.

    As for the RR stabilizers or any retractable for that manner, they are too thin to get sufficient torque to do a great job of zero speed.
    That is why the Quantum sets are so long.

    Thanks
    Oceaneer
  3. K1W1

    K1W1 Senior Member

    Joined:
    Sep 30, 2005
    Messages:
    7,390
    Location:
    My Office
    Hi,

    The results of model testing are only really applicable if the end result is exactly or very very close to the same as the model that was tested.

    I have spent a lot of time going up and down in the HSVA Test Tank with a few others including Theo Koop looking at the use of the forward set of a 4 fin setup as a pitch control device.

    Their results were used to determine the viability of a request that had been made by the Owners Team at the specification stage owing to the the narrow window of what we expected the cruising speed to be and the speed where the system worked best.

    The Test Tank results were very close to what was recorded 3 yrs later in real life mainly because the yacht that was model tested was exactly the same as the one that was built.
  4. BMcF

    BMcF Senior Member

    Joined:
    Mar 8, 2007
    Messages:
    51
    Location:
    Maryland

    All of that. :cool:

    I've been involved in the model testing of more actively-controlled vessels than I could count without some serious reflection (and some of the tests in collaboration with my good friends Theo and Hans..;) ) and with very good correlations achieved between the tank testing and full-scale results. But good results do not happen by accident; it took a long time to get it all worked out correctly when it comes to correctly scaling and interpreting results.

    I will say this..model tank testing with active stabilization systems was a veritable nightmare and hugely expensive when I/we first started doing that back in the mid 80s. Today?...the wide variety of compact control systems, sensors and servos, etc makes it so much easier and cheaper to do.
  5. BMcF

    BMcF Senior Member

    Joined:
    Mar 8, 2007
    Messages:
    51
    Location:
    Maryland

    Its simple geometry really. As stabilizer designers, we adhere to Moore's Law when ever and where ever possible in the sizing of the equipment. (to the eternal chagrin of the designer/NA that is obsessing over the added drag..:cool: ) On many hull forms, it is simply impossible to get the wiggly bits large enough to do an adequate job of motion stabilizing without them sticking out beyond the beam ends.