[tuglugs]

I am trying to find information on which Gyro stabilizers to fit to a heavy displacement round bilged "explorer yacht".
Mitsubishi have been doing them the longest - but does anyone have any experience of the new 'Sea Keeper' gyros that claim to be more efficient because they work in a vacuum??
Thank you.

[emrantambe]

plz xplain me how anti rolling gyro stabillizer works

[golden_fox]

Originally Posted by tuglugs

I am trying to find information on which Gyro stabilizers to fit to a heavy displacement round bilged "explorer yacht".
Mitsubishi have been doing them the longest - but does anyone have any experience of the new 'Sea Keeper' gyros that claim to be more efficient because they work in a vacuum??
Thank you.

I have actually spoken to the guys of Mitsubishi in Japan and they keep telling me that there systems are built under an exclusive contract just for Ferretti.

Another very good one is Sea Gyro (from Australia) and the guys there are very helpful as well. Check out www.seagyro.com
They have a good range of of gyro stabilizers for yachts of various sizes and displacement. you will be able to get the details from their website. i do have information on their systems as I got them all down for the a 29m yacht that I am currently building. if you want, I can send whatever information I have on their systems.

Cheers,

[CODOG]

Originally Posted by emrantambe

plz xplain me how anti rolling gyro stabillizer works

Its basically a very large version of the sort of toy gyroscope you may have had as a child. The essence of a gyro stabiliser is a very large and heavy flywheel that rotates at considerable speed around a transverse axis. Utilising the principles of angular momentum, the properties that enable gyroscopes to resist external torque can be used to minimise transverse roll on a yacht when the gyro is fixed solidly to the vessels structure. The larger the gyro / the faster it rotates, the more pronounced the roll dampening effect. Due to economies of scale and packaging, more than one unit may be necessary depending on the size and roll characteristics of the vessel.

[BMcF]

Originally Posted by CODOG

Its basically a very large version of the sort of toy gyroscope you may have had as a child. The essence of a gyro stabiliser is a very large and heavy flywheel that rotates at considerable speed around a transverse axis. Utilising the principles of angular momentum, the properties that enable gyroscopes to resist external torque can be used to minimise transverse roll on a yacht when the gyro is fixed solidly to the vessels structure. The larger the gyro / the faster it rotates, the more pronounced the roll dampening effect. Due to economies of scale and packaging, more than one unit may be necessary depending on the size and roll characteristics of the vessel.

...and...in the case of the Seakeeper gyro, it is also actively 'tilted' in its support foundation, in response to roll angle and rate, to gain additional damping forces when needed over what is achieved with a fixed-mount gyro like the Mitsubishi. Though the Seakeeper is reportedly more effective on a 'size for size' basis, I've not yet seen any hard data that compares the performance of the two types for the same vessel size/hull type. What I have seen is that both types do work...quite well in some cases, dependent on hull form and gyro size.

[wdrzal]

State of the art in gyroscopes are "Ring laser " and a little older "Fiber optic" they use a interferometer and have No moving parts.

here a wiki link to get you started,you can google if interested.

http://en.wikipedia.org/wiki/Ring_laser_gyroscope

[K1W1]

Originally Posted by wdrzal

State of the art in gyroscopes are "Ring laser " and a little older "Fiber optic" they use a interferometer and have No moving parts.

here a wiki link to get you started,you can google if interested.

http://en.wikipedia.org/wiki/Ring_laser_gyroscope

I think the original poster was asking about Gyro stabilization to improve comfort on the boat not so much to see if he was steering a straight course

[Skiffy]

Has anyone here any good or bad experiences with the gyro stabilisers? what makes were they and what if anything was the problem? what size of boat and what sized waves/swell were they happy with, on paper and dockside tests with heavy bods they seem pretty effective.
This might help me towards a decision so thanks for your input.

[Skiffy]

I'm aware of what they are and how they work and have seen demo's at the dock side, but I was hoping someone here may have had some practical experience of using a vessel with them fitted. I've seen the Australian one and the vacuum one but would like to have some feedback from a user.

Same as Tuglugs I guess!

[AMG]

Skiffy, I merged your new thread with an existing so we don´t have multiple threads on the same topic. Maybe there are not that many with this kind of systems out there yet, but hopefully you will have an answer soon..

[CaptTom]

Can't say I used them, but doing a review of a 70-foot Bertram for an article, this baby had two Mitsubishi ARG boxes installed in the aft engine room area. I was told that Bertram is making this an option on all new yachts, and building in the mounting pad during construction even if you don't order the gyro when new.
Rep for imstall/tech company specified that they should reduce roll by about 50% or so. Mitsubishi had an eclusive with Ferretti, but was told that it either lapsed or was to do so soon (told this a couple months ago). Didn't get a chance to turn it on during my sea trial. Box is maintenance free and you flick a switch to turn on, but it can take 20 minutes or so to get up to full rpm. Don't have my notes handy right now otherwise I would give a few more specs. Definitley would like to try it and may call Bertram to get a demo for an article.
Here's a shot of one of the two on the 70.

[Skiffy]

merging the post!! I understand now I've seen the dates of the posts!
Thanks Tom, it looks quite a big lump!

[GFC]

A short and sweet explanation of how one of these would work to stabilize a boat would go something like this...


Gyroscopic principle says that if a force is applied to the axis about which a gyro is spinning, the resultant force will be re-directed 90 degrees.

For example, if you mount a gyro with the axis perpendicular to the keel of a yacht (port to stbd) and have the gyro spinning around that axis, it would be spinning in a plane that runs along the keel.

Any force applied to the gyro through the roll of the boat's hull would be perpendicular to the axis around which the gyro is spinning. That force would be redirected 90 degrees and in a direction that would try to turn the yacht. Obviously turning the yacht (changing its course) takes a lot more force than it does to make the yacht roll side to side. Thus the redirected force would be "lost" by the resistance of the yacht to turning.

Now, have I thoroughly confused this issue?