Gyro stabilizers

[jimmy_the_builder]

Installation is being done mostly by team of shipwrights flown and driven in from Scotland. We like them! With bit of help from me and my father, mostly making tea. He bought the stabilisers direct from sleipner in Norway - shipped in a couple of big crates. Easy stuff really. Work is being done at Bleumer's yard; lift out is tomorrow am. Deserves a thread!

Yep the boat had koopnautic fin stabs but they are just such pathetically poor engineering you cant wait to throw them in a skip. They are not zero speed. And they are mounted too far aft by Aquastar, so they induce fishtailing yaw torque.

All this was factored in to the economics when he bought the boat. Cost of changing them is same as cost of installing new, as MapisM says above. nothing at all is re-useable from the old system, because it is junk

I hope you're filling the hole from the old stabs with something suitably Lumishore-y...

 

[MapisM]

Yep to all that Mapis M - except that, more theoretically than noticeably, gyros induce yaw.

I never thought about it, but I perfectly see your point. It might even explain the feeling A&K described...

 

[MapisM]

I don,t feel I ve missed out not having stabs in a leisure boat -emphasise on the leisure side just feels a waste of money to me.

Even if I'm a stabs fan, I can't disagree completely - to the point that, as I mentioned in another thread, I am thinking to have a look also at power catamarans.
Which by definition don't have stabs, but are inherently stable enough in most leisure (emphasized, as you said) conditions - at zero cost, and without needing a genset at anchor.

That said, you don't want to be cruising for any meaningful amount of time with your Itama in sea conditions forcing you to slow down at D speed.
My bet is that the ride would be rather scary than just uncomfortable, because the deep V that works so well at high speed is a recipe for an awful rolling motion at D speed, with a very short period and sudden snap-back after each roll.
I'm not wishing you to encounter such conditions unexpectedly of course, but that would make you reconsider what you are missing with a non-stabilized boat, I reckon...

 

[MapisM]

I hope you're filling the hole from the old stabs with something suitably Lumishore-y...

LOL, talk about lateral thinking... :encouragement:

 

[BartW]

.... to the point that, I am thinking to have a look also at power catamarans.

pls Mapism, take a cold shower and have a lie down !

 

[curiouskb]

I found the specs have changed for the MC2 20 after Quick took over. The old spec MC2 20 angular momentum is quoted 3500 nms, the new Quick one is 4790 nms. The old spec anti roll torque 9300 nm, and Quick web quoted 12563 nm. Quite a big difference in output!
Are these the same machines or Quick did some modifications to booster the output? Interesting to find out.

 

[vas]

Cost of changing them is same as cost of installing new, as MapisM says above. nothing at all is re-useable from the old system, because it is junk

John, I wonder how your brother's crap stabs would work on a smaller craft

If you're really planning to scrap them, I'd start thinking of a new project for MiToS...
Keeping the h/d and redoing the control s/w with a few arduino's (or even something faster like a raspberry or a banana pi

cheers

V.

PS. I'm semi-serious on that

 

[jfm]

John, I wonder how your brother's crap stabs would work on a smaller craft

If you're really planning to scrap them, I'd start thinking of a new project for MiToS...
Keeping the h/d and redoing the control s/w with a few arduino's (or even something faster like a raspberry or a banana pi

cheers

V.

PS. I'm semi-serious on that

You could drop them in and they would work u/way, no problem. To convert them to zero speed, you need more than controls and software and proportional vlaves. You need to change the fin design. Underway stabs have the drive shaft somewhere near the middle, to reduce the torque needed to operate them. Zero speed stabs must have the drive shaft right at the front edge, so that the entire surface of the fin is flapping in the same direction in zero-speed mode. Thaty would be quite a big job to mod, though of course everything is possible (especially if you get on the case Vas!).

If they come out unscathed let's discuss. Alas there is risk that the shafts will be cut. A 9 inch angle grinder is already in the tool kit, in case the fins cannot be pulled off their tapered joints

 

[Deleted User YDKXO]

No, you don't.
SD2 already had some non-zero speed fins, but unfortunately (you can guess why I know that! ) upgrading from non-STAR to STAR fins is almost as expensive as fitting a whole new equipment.
On top of that, jfm explained in this post that they are also moving the fins positions, due to a (rather amazing, I must say) build mistake.
I am mentioning this because it's a remarkable exception to what I said in point 1 of my previous post ref fin stabs not creating any yaw motion: if Aquastar placed the fins more astern than they should have been, of course that can create a yaw motion, making the boat "fishtail", if I may steal the expression jfm used, which I think is pretty effective.
But of course, that ain't an inherent problem of fin stabs per se, just of their incorrect placement.

Thanks missed that post

 

[Deleted User YDKXO]

Even if I'm a stabs fan, I can't disagree completely - to the point that, as I mentioned in another thread, I am thinking to have a look also at power catamarans.

Dont blame you. I think a power cat would be perfect for the CF area and the kind of liveaboard cruising you do. And I guess Sifredi wont charge you too much for parking it either

 

[vas]

You could drop them in and they would work u/way, no problem. To convert them to zero speed, you need more than controls and software and proportional valves. You need to change the fin design. Underway stabs have the drive shaft somewhere near the middle, to reduce the torque needed to operate them. Zero speed stabs must have the drive shaft right at the front edge, so that the entire surface of the fin is flapping in the same direction in zero-speed mode. That would be quite a big job to mod, though of course everything is possible (especially if you get on the case Vas!).

If they come out unscathed let's discuss. Alas there is risk that the shafts will be cut. A 9 inch angle grinder is already in the tool kit, in case the fins cannot be pulled off their tapered joints

John,

on a more serious note such a project does not look impossible. Heck MiToS was impossible for many ppl when they saw it on the hard and who thought I was a complete nutter and was never going to make it. Admittedly ppl in this forum had been quite kind to me, at least publicly and their support (on many grounds!) was instrumental to the completion and relaunch of MiToS, and I'm really grateful for that!

I'm on a rather boring day long meeting at the Ministry of Education, so have plenty of time for thinking but not enough time for googling around... Tried finding specs and drawings for Koop Nautic, wasn't very lucky, looks like it's part of half a dozen companies that merged into Naiad. So my "main" lack of info is on the actual size of the bilge installed machinery. Have a decent completely empty space outside the two engines all along the length of the engines so I would expect that such a gear/pump would fit on the forward section just aft of the tanks. Having seen where the fins are on Match and BA it looks more or less on par. Nah, had a look again, I was talking bull, got to be under the floor of the port cabin and the space under the air con on stbrd side. Space is a bit more critical there, although it can be adapted with not much trouble. Also possible to reinforce on the inside although gearbox/pump/motor assembly size becomes an issue.

Considering your brother's boat is iirc 74ft and MiToS is only 43, I'm pretty sure that shaft/torque and all other parameters are going to be more than sufficient even for offset (zeroish speed) fins. Regarding the removal, imho and in all seriousness it would make more sense to butcher the fins rather than the shafts! Fins can then be modded reshaped (and reduced in size that's going to be necessary if fit on a smaller craft), redoing the shaft is not impossible but slightly more challenging.

anyway, if you wish we can discuss that once removal work is completed although a couple of pics of the hull installed kit would be nice to examine.

cheers

V.

 

[MapisM]

pls Mapism, take a cold shower and have a lie down !

Haha, don't worry, B.
Believe it or not, today I went to check out a Lagoon Power 43, and it took me no more than 5 mins to decide that there's a limit to the build quality compromises I'm willing to accept.
The construction of that thing is, quite simply, appalling. Makes my old tub a high-end luxury battleship, in comparison.

That said, ...

Dont blame you. I think a power cat would be perfect for the CF area and the kind of liveaboard cruising you do.

...I knew you would have understood my train of thoughts, M.

And you know what? After viewing that 10 years old LP which was almost falling apart , I still think it's a kind of vessel which would make sense in many ways, not just for my own needs, but also for many other boaters.
In fact, I would dare predicting that power cats will be the highest growth segment within the mobo industry, in the next decade.
As soon as some builders will understand that there's a potential market for these vessels, and will leave aside the yogurt pot approach to construction, I bet that we will see some very interesting stuff.
On paper, the FP MY44 looks like a step in the right direction, for instance. But I'm not willing to fork out ridiculous amounts of money for a new boat anyway.
Otoh, I don't think there is anything yet on the used market which can be remotely worth considering, so...
...the powercat idea is set aside for the next life, and back to the drawing board!

 

[MapisM]

Considering your brother's boat is iirc 74ft and MiToS is only 43, I'm pretty sure that shaft/torque and all other parameters are going to be more than sufficient even for offset (zeroish speed) fins.

I'm afraid you are being optimistic, V.
It's not just a matter of shaft size/torque handling, but also of actuators control and speed.
If it weren't that I know what you've done with MyToS, I would have just replied forget it...

 

[Deleted User YDKXO]

Believe it or not, today I went to check out a Lagoon Power 43, and it took me no more than 5 mins to decide that there's a limit to the build quality compromises I'm willing to accept.
As soon as some builders will understand that there's a potential market for these vessels, and will leave aside the yogurt pot approach to construction, I bet that we will see some very interesting stuff.

Yup you got it in one and that is the main problem with power cats. The builders are also making cats for the sailing and charter markets and they can't change their mindset to up their game for the more discerning power market. It needs a big powerboat manufacturer to get into the game and demonstrate how it should be done

In fact, I would dare predicting that power cats will be the highest growth segment within the mobo industry, in the next decade.

Yes I agree. The combination of massive living space, fuel economy and stability will be increasingly attractive to boaters with families and older boaters looking for blue water capable liveaboard boats

FWIW the only power cats I've seen on the web which seem to be built to, lets say, power boat standards are the Horizon models https://www.horizonpowercatamarans.com/ Not even sure that Fontaine Pajot get the market either

 

[Portofino]

We have 6 arriving this season in La Napoule - A chater Co has "invested "
There seems to be a demand for holiday rental in the SoF in a Hoeseasony way .Guess accomodation ,fuel efficiencey and stability wins hands down ,for hol renting .

So just be aware of the potential imagery around that !

They are making a new pontoon in the marina ,ready for them .Its in the public / fishing side of the port .

The operator has been looking at this for a while and along with the local Mayors office blessing - for us to fit them in ,we were given another lease extension ,taking it to 2029 .
Idea is to bring in more weekly holliday foot fall and associated boost to local buisness --- well in theory ?

Perhaps that kinda answers the Q ,s re reconciling the build quality and luxury MoBo,s ---they are not aimed currently at the same mkt .

 

[Bouba]

This growth in charter cats is worrying. In my marina, which is a river, there is a hire company next to us. Already they park two abreast and occasionally three. It doesn't take too many fifty foot cats to block a river and take all our maneuvering room. And I'm sure they will expand. I personally would charge them for two places instead of one and a half. It's not like you can fit a half boat in the gap.

 

[Deleted User YDKXO]

We have 6 arriving this season in La Napoule - A chater Co has "invested "

You mean 6 powercats? What type?

 

[Portofino]

Yup ,I think they will pay the full going rate rent width wise ,which is added to marina income ,so in effect they will subsidise ,dilute the running costs keepng the maintenace costs lower than what they would have been without them . They are 50 ftrs too .It was all discussed at a EGM and ratified at the last AGM ( Sept ) .Berth holders here are all shareholders ,and have a say in the running .We hire n fire too !
These things have a long gestation period .

 

[Portofino]

You mean 6 powercats? What type?

I think so .Sorry don,t now which type ,only L 50 ft
That area in the Marina is ( was there last Monday ) a building site in reparation .

BTW was in Antibes last Sunday -had a nose around -- your boat looked fine , as did the others in Antibes mob that I know off ? -

Think it will be ready boats on new pontoon moorings for the summer ..
It's the entrance and ferry dock that is being remodelled .
In PV think of the equivalent space on the RHS entrance at the corner of the ship yard ,you currently have 1/2 dozen scapy spaces there.
That "similiar "space is on the LHS as you enter La Nap .

 

[MapisM]

FWIW the only power cats I've seen on the web which seem to be built to, lets say, power boat standards are the Horizon models https://www.horizonpowercatamarans.com/ Not even sure that Fontaine Pajot get the market either

Good point. I didn't even think to consider the Horizon because, aside from the fact that I'm not aware of any around for sale, their smaller model is a 52.
And even without having ever seen one in flesh, with an almost 16x7m size, she's bound to be much larger than we need.
In fact, I must say that leaving aside the build quality (and some silly layout choices), in terms of liveaboard spaces the LP43 has just about everything that 55' to 60' monohulls can offer.
And yeah, I suppose that FP might well be similar to Lagoon in terms of building approach - when I said that the MY44 "looks like a step in the right direction", the stress was on looks...