Anything good or bad about seakeeper gyros?

[Deleted User YDKXO]

Interesting discussion here. Jfm can you clear up one point for me. Stupid question but can you run your fin stabilizers at rest without gennie or engine power and for how long? I would have thought a test comparison between your fin equipped boat and NickH's gyro equipped boat in marginal sea conditions and at rest would make a very interesting magazine article. How about it, MBM or MBY?

 

[jfm]

Interesting discussion here. Jfm can you clear up one point for me. Stupid question but can you run your fin stabilizers at rest without gennie or engine power and for how long? I would have thought a test comparison between your fin equipped boat and NickH's gyro equipped boat in marginal sea conditions and at rest would make a very interesting magazine article. How about it, MBM or MBY?

Mike, I can't run my stabs without either an engine or a 230v pump. Underway I use engines and at anchor I use genset. But for 75% of the day on a boat like this I'm running genset anyway, for cooking and airco, and my batteries don't last long in daytime with all the refrigeration

Yes it would be good to do a side by side test. At anchor it would be a close run thing - both would be good. In mild seas, ditto. In big seas, the gyro would not have a cat in hell's chance agianst fins. Fins can produce something like 10x the antiroll torque of gyro underway, with no end-of-stroke limitation

One of the videos sleipner shot a nonth ago was of my boat at anchor alongside another Sq78. I don't know how good the footage turned out to be as I haven't seen it yet but I'll keep you posted

 

[Nick_H]

Lozzer, thanks for the info. I also hadn't appreciated the "run on" issue, and I can see that being a PITA, frinstance if they've been running during the day then we want to tender into the town for dinner, I wouldn't want to leave the genny running. The water req't isn't that great (10L / min I think), so I'll investigate whether a 24V pump could be specced instead or as well.

 

[Lozzer]

Nick

Just had a look at the manual

http://www.seakeeper.com/files/manuals/m7000a/90052-REV 4 M7000A OPERATION MANUAL 01FEB11.pdf

and you are correct in your volume of water.

Reading the lit it seems you can run 24v Raw water pumps, for whatever reason I am sure we had 240v This manual is also showing a different run down to that I was shown by Fairline. So perhaps there will not be the hours to kill.

Eiter way, I think it will certainly make your boat stand out from others in the future.

I am sure I speak for others when I say I look forward to seeing some pics of the project to install.

Good luck.

 

[MapisM]

I don't think that's right Mapis. The motherboard in my stabs controller has perhaps 20 processoers on it and it measures about 300mm square and is 7 layers. That's a load of computing power. It has much faster/higher resolution gyros and inclimometers than what was on the market 10 years ago. Electronics have moved on by several orders of magnitude in 10 years. The speed of the calculations is way higher now and timing is everything in stabs

Yup, 'course it is. My point was simply based on the observation that my system, which is 15 rather than just 10 YO (and possibly designed 20 years ago, I'm not sure), while underway works just perfectly.
I cannot imagine what sort of improvement a more sophisticated control system could bring - though in principle I can accept that for zero speed operation, this can make some difference.

I'm struggling with your logic. Stabs are better but you'd spec gyros???

LOL, you're saying that you don't turn the stabs off at 20kts in sea conditions you would never choose to go out in normally, and you struggle with MY logic...?
What I said is that in those conditions I would NOT go out, and if I should, I wouldn't go at 20+ kts, regardless of how effective the stabs are.
To me, full planing speed and stabilization is a sort of oxymoron.
And again, it's a matter of compromises. Boats which can cruise at 20+ kts are normally capable of 30 or more. In this speed range, I'd rather live with a less effective stab system than have a couple of shafts perpendicularly attached to the hull sides...

MapisM, you have to come out on my boat some time.
...
and I assure you that you will then retract what you have written above

Well, I don't think I will, but of course I'm more than glad to give you a chance to convince me!

 

[Deleted User YDKXO]

Mike, I can't run my stabs without either an engine or a 230v pump. Underway I use engines and at anchor I use genset. But for 75% of the day on a boat like this I'm running genset anyway, for cooking and airco, and my batteries don't last long in daytime with all the refrigeration

Thanks, I wondered whether you were running them for periods off your inverter

 

[BartW]

What I said is that in those conditions I would NOT go out, and if I should, I wouldn't go at 20+ kts, regardless of how effective the stabs are.
To me, full planing speed and stabilization is a sort of oxymoron.
And again, it's a matter of compromises. Boats which can cruise at 20+ kts are normally capable of 30 or more. In this speed range, I'd rather live with a less effective stab system than have a couple of shafts perpendicularly attached to the hull sides...

During our trip a few weeks ago, I did a few very early departures (6am) while the other folks were sleeping,
along Livorno coast, The sea state was good F2-F3, perfect for a smooth 20kn planing speed, but there were some nasty long beam waves, coming from strong winds far away,
and these were very enoing for the guests in bed so that all of them woke up.

discussed seriously about the need of stabilisers at that moment,
we even considered retrofitting them (just for a few seconds fortunately )

so I believe they are usefull at speed

but I am with you on the oxymoron of stabilizers at full speed planing, but isn't a big planing multi tons Motor yacht not a oxymoron on its own ?
not that I regret having one (yet )

boat stabilising seems to be the hot topic of this summer interesting !

 

[MapisM]

I am with you on the oxymoron of stabilizers at full speed planing, but isn't a big planing multi tons Motor yacht not a oxymoron on its own ?

ROTFL, can't argue with that, particularly considering that the statement comes from a 70T planing boat owner!
As you know, my idea of P boats is that unless they're capable of 50+ kts, I rather stick to displacement...

 

[Nick_H]

Well, its my lucky day. The gyro was due to be shipped today, but Seakeeper weren't happy that they'd had time to fully test the refurbed unit, so rather than delay shipment they've shipped a brand new 8000 series gyro.

Obviously I can't comment on the performance of the unit yet, but dealing with Seakeeper has been a pleasure from the start.

 

[jfm]

Well, its my lucky day. The gyro was due to be shipped today, but Seakeeper weren't happy that they'd had time to fully test the refurbed unit, so rather than delay shipment they've shipped a brand new 8000 series gyro.

Obviously I can't comment on the performance of the unit yet, but dealing with Seakeeper has been a pleasure from the start.

Blimey Nick, that's fantastic. Yes, the guy in the Cannes boat show stand from Seakeeper (who you had been emailing/talking to) was certianly a very nice (and clever/interesting guy). I hope the project goes well and look forward to the results

If ever you sell that boat, it must make sense to take out the gyro. It will never add to the value of the boat the cost of buying one all over again. So, it's better to remove it then install in new boat. In which case, you should ask the installers to fit it in a way that allows easy removal, at least where they have a choice. Eg do not cut wiring looms short but coil up the excess, etc etc.

 

[longjohnsilver]

Good for them (and even better for you!), seems that stab firms gennerally give better than expected service. That's certainly my experience of Trac and in particular Golden Arrow Marine who replaced a major piece of malfunctioning gubbins in the control panel when it failed long after the warranty period had expired. And all done very quickly and at no cost to myself.

 

[Deleted User YDKXO]

Good for them (and even better for you!), seems that stab firms gennerally give better than expected service. That's certainly my experience of Trac and in particular Golden Arrow Marine who replaced a major piece of malfunctioning gubbins in the control panel when it failed long after the warranty period had expired. And all done very quickly and at no cost to myself.

I can't believe what I'm reading here, ljs! An old sea dog like you needing the comfort of stabilizers? Are you going soft in your dotage

 

[longjohnsilver]

I can't believe what I'm reading here, ljs! An old sea dog like you needing the comfort of stabilizers? Are you going soft in your dotage

Well that may be true but I still haven't worked out how to turn them on.........

 

[Nick_H]

I’ve resurrected this old thread rather than start a new one as some of the previous posts are relevant.

We had the sea trial of the gyro yesterday, and broadly speaking I’m delighted with it. The winds in Antibes were very light, but there was a 0.5-1m swell running, which is similar to the swell you can sometimes find in the local anchorages from a distant storm or a passing superyacht, so the results should be fairly indicative.

This vid shows the gyro working



The video linked below shows the boat rolling in a beam swell. At approx. 15 secs the gyro is engaged, and it takes about 5 secs to start working, so you can see the full effect from 20 secs. We had some bigger, steeper, swells come through later (off camera), which had the boat rolling fairly violently, and when the gyro was engaged the roll almost stopped, so i'm really impressed with the performance. I think it’ll make life at anchor much more comfortable, and let us stay out when we may previously have headed home.



We had similar results cruising at displacement speed, which opens up a whole new type of cruising to us. I couldn’t test it at planning speed as the props were too fouled to plane.

Noise doesn’t seem too much of an issue on the 8000 series gyro (It runs 20% slower, but has better controls, so still has 15% more torque). With the lazarette hatch shut I couldn't hear the gyro over the noise of our (relatively quiet) generator, and that’s before I fit any kind of acoustic box. The noise during wind down could be more intrusive once the genny is switched off, especially as the gyro takes 4-5 hours to stop after turning it off, and at some stages of the wind down the noise becomes cyclical, which makes it more noticeable than a constant noise. Hopefully the acoustic box will block that. Another good thing about the new 8000 model is that it doesn’t need cooling during the wind down, you can just switch it all off together, although Seakeeper suggest that it’s good practice to stop the gyro as you enter port, but allow the cooling pump to run until you’re tied up on your berth.

The installation has been done nicely, and when the box is fitted over the gyro I’ll still have reasonable storage in the laz, and in some ways better storage as I wont need to climb down the ladder to get anything. The installer had to steal a bit of room from the crew cabin, but it doesn’t really affect its useability.

So all in all, as I say, I’m really pleased with the results, and also very happy with the service from Seakeeper. They’ve kept in touch during the shipping and installation, and not to forget they sent me a brand spanking new gyro rather than delay sending the re-furb. You can’t ask for more than that!

 

[DTIM]

Very interesting Nick, I was watching like a hawk at 15-20seconds to see if I could notice the difference - need not have watched that closely - the difference when turned on was very obvious. Great result. Has the weight altered the trim at all?

 

[wakeup]

Looks very effective even more so from 28 seconds in.

I now realise that the gyro rotates about a single axis. I had assumed it would be gimballed in several directions to eliminate any change in attitude but it is really the side to side you want to eliminate more than anything.

 

[jfm]

Very nice stuff. The second video where you switch it on at 15 seconds is pretty convincing - I'm pleased that the result is that good

It will be interesting to hear later how it performs underway in a rolly sea

Good news on the noise front too

I had the benefit of seeing this machine in the flesh last Saturday on board Nick's boat and it looked a really neat installation and a beautiful piece of kit

 

[jfm]

Looks very effective even more so from 28 seconds in.

I now realise that the gyro rotates about a single axis. I had assumed it would be gimballed in several directions to eliminate any change in attitude but it is really the side to side you want to eliminate more than anything.

Yup, they are all like that wakeup. It spins abut a vertical axis, and gimballs about an athwartships axis, and so it applies an anti-roll twisting torque to the hull about the boat's fore-aft axis only. It woudn't have enough torque to make any difference to the boat's pitching, so it might as well be made as it is

The clever electronics control the hydraulic cylinders which control the precession, and that's how it makes sure the right torque is being applied to the boat's hull to get the best effect. Clever stuff, and way better than the Mitsubishi stabiliers on Ferrettis which do not have this feature. It looked the dog's doofers installed on Nick's boat when I had a look at

 

[wakeup]

Yup, they are all like that wakeup. It spins abut a vertical axis, and gimballs about an athwartships axis, and so it applies an anti-roll twisting torque to the hull about the boat's fore-aft axis only. It woudn't have enough torque to make any difference to the boat's pitching, so it might as well be made as it is

Really, I believe you, however I would have thought that it had a greater moment re the fore aft distance to cog than the moment athwart ships and therefore more influence fore and aft. More mass moving up and down to counter though I suppose.

 

[kashurst]

that looks very impressive - let us know how the boat goes at displacement speeds.