Experience with NIAD stabilizers on a GB42C

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Bongi

Veteran Member
Joined
Dec 6, 2021
Messages
98
Vessel Name
Scatterlings
Vessel Make
Grand Banks 42C
Folks, we are seriously considering adding NIAD hydraulic stabilization to our 1986 GB42C.

She has twin 3208Ns.

Active and electric fin stabilizers - as well as gyros - are about 40% more costly and the latter taking up too much space in an already tight engine room. I have seen a GB42C listed recently which had a Seakeeper 6 installed!

Some questions:
  1. Is mounting the hydraulic pump underneath or on the side of the engine preferable?
  2. How much "engineering" was needed to seat the slave components on the inside of the hull?
  3. Have they proven in any way effective in a VERY rolly anchorage?
  4. Are there any other options we should be considering?

In general we'd also like some comments whether your installations met your expectations. We've had NIAD fin stabilizers before, so have appreciated their assistance on a Californian 52, but would like to get the GB perspective.

Thanks in advance.
 
I'd consider fins useful underway, but I wouldn't consider them a great solution for a rolly anchorage. I'd prefer passive flopper stoppers for that scenario, as the fins will require you to keep a generator (with a hydro pump) running constantly at anchor when you want to use them (same as a gyro and possibly electric fins depending on their power draw).
 
I'd consider fins useful underway, but I wouldn't consider them a great solution for a rolly anchorage. I'd prefer passive flopper stoppers for that scenario, as the fins will require you to keep a generator (with a hydro pump) running constantly at anchor when you want to use them (same as a gyro and possibly electric fins depending on their power draw).

I am in agreement here. The fins must have some amount of positive affect in a rolling anchorage but it’s not enough to be noticeable.
 
...
She has twin 3208Ns.
...
Is mounting the hydraulic pump underneath or on the side of the engine preferable?

I'm curious what your thinking is for mounting a hydraulic pump on the engine. Our 3208n doesn't have much room for mounting accessories despite being a gigantic engine.
 
I am in agreement here. The fins must have some amount of positive affect in a rolling anchorage but it’s not enough to be noticeable.

If they're sized appropriately and are newer fins designed to provide zero speed stabilization they'll help significantly. My concern is more around the practicality of power them for long periods of time at anchor.
 
As luck would have it, we just anchored about 20 mins ago and I forgot to turn off my 2021 Wesmar stabilizers. They actually seemed to make the rolling at anchor worse.

I posted these pictures of my flopper stoppers this morning but will repost here. Forespar makes some decent kit but requires rigging on top of the gear. 2-yesrs ago, I paid around $1100 for each pole, and the magna plates were about $400 each if I recall. Plus rigging and such, probably $4k, maybe a bit more for both sides. World of difference. They take about 10-mins to setup or stow.

Finally, you may want to look at bumfuzzle.com. They cruised the entire Caribbean on a GB42 with stabilizers. They've sold that boat and are now back on a sailboat in the Pacific. Chances are they'd be happy to trade notes with you and answer any questions. They're exceptional writers and photographers.

Peter
 

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A caution. When refitting a boat not designed and built for stabilizers hire the best yard you can find with lots of experience. I delivered an Ocean Alexander from San Diego to Anacortes Wash that had been fitted with Niads. The installation was so poor I could watch the mounts flexing. I feared they would be torn out of the hull flooding the engine room so I shut them down and secured them, much to our discomfort.
 
A caution. When refitting a boat not designed and built for stabilizers hire the best yard you can find with lots of experience. I delivered an Ocean Alexander from San Diego to Anacortes Wash that had been fitted with Niads. The installation was so poor I could watch the mounts flexing. I feared they would be torn out of the hull flooding the engine room so I shut them down and secured them, much to our discomfort.

Agreed, having someone with a good structural background and/or lots of experience installing stabilizers involved in the project is a good idea. If all else fails, if there's any question about whether the installation is stronger than it needs to be, just make it stronger.
 
I'm curious what your thinking is for mounting a hydraulic pump on the engine. Our 3208n doesn't have much room for mounting accessories despite being a gigantic engine.

Yes.. fair question. The 3208 allows one to bolt on a belt pulley extension to the crankshaft pulley, which adds an extra belt groove or two. On my Californian I added a high capacity Balmar alternator this way on the STBD engine and the PORT engine had a hydraulic pump added this way for a NIAD stabilization system. Both worked great. In my case they were both mounted off to the side, but for safety’s sake I would like to explore mounting it below the engine on a bracket using a crankshaft extension. Here is a picture of the alternator in process of being located during the build process which illustrates the arrangement.
 

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we used Reinforced fiberglass panels epoxied to get a 4 inch build then tied all that to the chine,bulkheads and the main stringers. I am expecting to be able to sit on the fins. Do you have the room for the buildup where the fins need to be positioned for best performance? As for as the pump i was able to mount directly do the flywheel. Another install with the same boat i had decided to do a direct mount off the end of the crankshaft that turned out well without the need for belts.
 

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I added ABT stabilizers to a 2009 GB 47 EU, and except for the fiberglass work, did the whole job myself. It's covered in my blog, though I think the pictures have been lost. See www.MVTanglewood.com and look back in 2010/2011 or so.

In all honesty, I think it's going to be difficult to add stabilizers to a boat that's 45' or smaller unless it was originally designed and build with a designated space for them. But maybe you will get lucky.

GB was installing the same system in a sister boat to ours for one of their board members at the same time, and were very helpful with the required structural modifications. Thankfully there was a location where they would fit with minimal relocation of other equipment and cabinetry. But there was a stringer that needed to be cut and relocated, followed by lamination buildup, so still significant work. The 42 will have less available space than the 47, so as a starting point, I would figure out where the actuators will be located to see if it's even practical to add them. Finding another GB42 that has soen this would be great for figuring out a location, and finding out what layup enhancements were used.

I would also be cautious of the mounting method that Naiad uses vs ABT. The Naiad approach is easy for a yard to screw up, and I have heard of more than one that broke free later in their life. Naiads rely on a glassed in wood block, where ABT uses two substantial steel disks with the hull sandwiched in between. It spreads the forces out over a much wider area, and there is no way for it to break free, unlike the Naiads which depend on the bond strength of the block to the hull. There are lots of successful Naiad builds, but I think it's much tricker to do right, but most yards excel at doing things poorly, not doing them well.

Back to your original question about the pump, I would do everything possible to have the pump be direct driven off a PTO mount on either the engine or transmission, and use a belt drive only as a last resort. I say this because a lot of earlier Nordhavns were built with belt drive pumps, and they are very problematic. The belts don't do a good job with the surge loads that the stabilizers produce, so belt wear is problematic. Also they are equipped with a so-called overhung adapter that takes the side load of the belts because the pump itself isn't designed for that. Those adapters are prone to bearing failures. The whole system just isn't as robust as a PTO driven pump. Most engines have one or more PTOs, and one is often used for the seawater pump. If there is another one available, great. Otherwise look to the transmission since they ofter include, or can be outfitted with a PTO. My boats have all had the pump on a transmission PTO.

As for at-rest stabilization, no matter how you do it, you will need to run a generator, either to produce electric power for a gyro or electric fins, or to directly drive another pump via a PTO. And whatever power is used by the stabilizers, you will no longer have that available from the generator for other loads like HVAC. So figure out the generator sizing very carefully, whether a PTO and pump can be added, etc.
 
In all honesty, I think it's going to be difficult to add stabilizers to a boat that's 45' or smaller unless it was originally designed and build with a designated space for them. But maybe you will get lucky.

I think it's a little bit of luck as far as having a good spot (both placement wise and structurally) to add stabilizers. But also the type of stabilizers may need to be chosen based on what will fit best rather than a preferred type or brand.
 
Was wondering if any of you have experience with the pneumatic Gyro-Gale stabilization system... there was at one GB42 installed with it.

This is a smaller interior foot print on the actuators and is claimed to be an "active fin" stabilization system due to faster response times over hydraulics.

https://youtu.be/n7_jsKK4tu4?si=K0BXiUVc2_fY1Kgh
 
Active and electric fin stabilizers - as well as gyros - are about 40% more costly and the latter taking up too much space in an already tight engine room. I have seen a GB42C listed recently which had a Seakeeper 6 installed!

I have some good news for you, gyros do take up a lot of space, but electric stabilizers don't take up a lot of space at all. In fact they take the least amount of all stabilizers
I installed mine (waveless stab 25) last year and in the ER (on the inside of the hull) they are about 5 to 6 inches high, that is all. There are no hydraulic lines, no actuators, no moving parts on the outside, just an electricity cable going in.
The control box is required for all stabilizers, so that is about equal.

And then the second part of the good news, they work perfect on anchor and also in port, they are zero speed and keep you absolutely stable, no more rocking and rolling. Stabilizers won't stop the pitching of the boat, they will reduce it a bit, but you will pitch. Rolling however is past time, also on anchor and in port.
We basically have them 'active' 24/7, there is no need to switch them off and the electricity usage through the night is minimal. As soon as they detect a disturbance they will react instantly.
The motors are rated for 2 Kw (at 220V) a piece, but I have seldom seen over 300 W in total, even when it is rough in the anchorage. And when the sea is calm, you have them standing by, ready to act, but they won't use any electricity. Hydraulic stabilizers will always need that hydraulic pump to run.

I have no idea what the price would be of a Naiad system in 2024, but when I checked 2 years ago the difference was negligible. I often have the idea the producers of stabilizers look at each other and simply follow what the trend is. I find it kind of strange that all producers have basically identical prices.

I had mine installed, but I have spoken with an owner in the US who did it himself, so it can be done.

Stabilizers are there for comfort and once you have them you wish you had installed them much earlier, we love them !
If you are seriously thinking about installing stabilizers I can highly recommend thinking about electric stabilizers, they keep you stable while underway, on anchor and in port. They are able to keep you stable on anchor because they can react much much faster than hydraulic stabilizers and they can continuously change the speed at which they work, something hydraulic stabilizers are incapable of doing since it needs a certain pressure to be able to function.

As others have stated, for every stabilizer you will need to reinforce the hull and you have to make sure that is done correctly. The forces stabilizers can put on the hull are enormous, you don't want the hull to crack open like an egg shell.

Good luck with your decision and if you are interested in electric you can look for the waveless stab 20 for your boat. They are made by CMC marine, the company that invented the electric stabilizers.
 
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Was wondering if any of you have experience with the pneumatic Gyro-Gale stabilization system... there was at one GB42 installed with it.

During my search I also looked into pneumatic, but it does require a large compressor and a large tank. Then you have all kinds of other equipment (coolers, air dryers, filters) and of course the pneumatic lines.
But my biggest objection was the immense electricity usage. For my boat I had to get a 4 Kw compressor and I could not power that through the solar panels. Since I only have a 6 Kva generator onboard (which we hardly use because of the solar panels) I would have to dedicate that generator completely to the compressor for the stabilizers.
The fuel usage, the noise and the fact that I had to run that all the time in order to have stabilizers was a no-no for me, so that was the end of the pneumatic stabilizers for me.
 
Thanks Mambo42 for that clarity on the compressed air option… my genset is only 5.5kva so that would also be an issue for me.

I’m now seriously looking into a getting a gyro since I have seen two GB42C,s with gyros…. a Seakeeper 5 and Seakeeper 6. Installing these was not without its challenges, including in one case cutting a hatch in the floor to be able drop it in.
With the advent of the Seakeeper 4.5, it’s high performance with a smaller footprint should make it easier to install without cutting up the floor… but will need cutting into the stringers which will keep it’s profile low in the engine room. See the example below…
 

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My 05 GB 42eu had factory stabilizer prep on the build sheet and has ABT Trac hydraulic fins that appear to be of the same vintage, so maybe also factory. They run off the PTO on the ZF 280-1a transmission. Seems to work great - haven’t been in anything too uncomfortable. They’re just forward of the fuel tanks in mine (but I have a single). I’ll try to post a pic. If I was starting from scratch those mangus? effect things are interesting - like the idea of just one, if it works. Gyros power demands seem unreasonable to me, but as I already have something else, I haven’t really researched the alternatives. Good luck!
 
Sorry not a great pic for this purpose. The hull is a thicker pad and there is a “bite” taken out of the stringer.
 

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Little better. It’s basically below the helm seat.
 

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my genset is only 5.5kva so that would also be an issue for me.

I’m now seriously looking into a getting a gyro since I have seen two GB42C

Keep in mind that a gyro literally guzzles electricity and takes about 30 - 45 min to spool up. With that in mind you basically have to keep it running all the time and that takes a lot of electricity. Since you have a 5.5 Kva generator most of that capacity will need to be used for the gyro.

Since you will have to have it on all the time you are also putting a lot of hours on the bearings. When I was researching stabilization the bearings needed to be changed every 3000 hours (think it now went up to 5000 hrs), but in order to be able to change them they will need to take the whole gyro apart. This translates into a lots of time, lots of money and lots of risk.

For me those were the 3 reasons (electricity, spool up time and maintenance) why I did not want to have a gyro onboard.
Later I heard that the gyros also make quite a substantial amount of noise, so you will need to do sound proofing.
 
Thanks Mambo42 for that clarity on the compressed air option… my genset is only 5.5kva so that would also be an issue for me.

I read that the Seakeeper 4 takes between 110 and 148 amps at 12 V per hour (incl cooling pump and control box), those are staggering numbers. If you want to run that through your batteries each hour you will have quite a bit of problems. In other words you will need a dedicated 12 V source that can handle so many amps.

Spool up time to full rpm is 1 hour and to initial stabilization is 45 min.

Also, it states that the gyro is 44.000 USD, but that does not include installation, so how much will be the installation cost ?
When you do your research you will find out that all the other manufacturers will end up roughly around that same number for your size boat. Only Humpfree was a bit more expensive if I remember well.

If you are curious to see what the stabilizers look like when they are working in port, go to this instagram video https://www.instagram.com/p/CzqokmHt4fL/

It was dead calm that day, so we had to rock the boat ourselves a little bit, then switch on the stabilizers and get them to react. But as you can see on the video, by the time was able to get the boat was already stable again.
 
While I have never owned a boat with active stabilizers, I have five friends and one boat yard who have experience with all of the aforementioned hydraulic systems and the sea keeper. They all work very well in a perfect installation. You should realize that you are taking on a major system regarding maintenance, monitoring, and troubleshooting. The systems are miraculous, but have sensors, control units, and smart actuators that will require your troubleshooting ability at times – guaranteed.

Another factor to put in your choice is where you will be traveling; consider if the manufacturer can get a technician to you without too many airline legs.

The DC electric fins made the most sense to me when I was looking to purchase, especially since I have experience with DC electrics and almost none with hydraulics.

If you are mostly trying to tame the boat in a rolly anchorage, you should really consider flopper stoppers, especially since you have a nice boom on your vessel already.

Good luck and keep us posted.
 
Biggest regret

My biggest regret in my boating career is selling my Ocean Alexander 456 that had ABT Trac stabilization. I have been in some serious blows and some fairly rough. Seas and the boat came through with zero issues. More importantly the crew also came through with zero issues.

One thing to consider is the maintenance interval on the stabilizers and whether it can be done by yourself. The interval on the stabilizers we had was five years. With some coaching from customer service was able to service them myself. It was not a difficult job, but it is necessary to understand the sequence and how to calibrate the fin sensor.

The the stabilizers experienced some maintenance issues. I had to rebuild both hydraulic pistons that drive the fence. I also had to replace part of the computer. Including rebuild kits computer hydraulic repairs I probably have spent four to $5000 on maintenance in five years I think that was some of the best money I spent ever on a boat, once you have had active stabilization, you won’t want a boat without it.

I made the mistake of selling the boat and then buying a power catamaran in the Adriatic. I sure miss my Ocean Alexander and the stabilizers.

On our installation, the ABT Trac installers, put a hydraulic pump mount on the front of the Cummins , 330 hp engines. Both engines had a hydraulic pump that could be selected with a switch. If one pump went out, a simple change of the switch would put the other pump online.

Another maintenance issue for a hydraulic system is the seawater cooling system. It will also require annual or by annual impeller changes.

I have been looking for a monohull in the Mediterranean, and have found two Grand Banks 42 foot boats that have hydraulic stabilization.
 
Just my 2 cents, I have Niaids on my Californian 55 and they work great underway, at anchor, no. My hydraulic pump is attached to the port inboard stringer in front of the port engine. I don't think the pump has an impeller as it works fine and has not been touched for at least 10 years. Service in my area is a bit of a problem, there seems to be only one experienced tech and he charges $165/hr including portal to portal transport. The oil reservoir and control system is rather large on my old model 272. I had Baja Naval in Ensenada MX do the external bearings, bolts and seals in 2021 and I believe they charged about $2,500 for the job but I brought the parts with me.
 
You should realize that you are taking on a major system regarding maintenance, monitoring, and troubleshooting. The systems are miraculous, but have sensors, control units, and smart actuators that will require your troubleshooting ability at times – guaranteed.

Another factor to put in your choice is where you will be traveling; consider if the manufacturer can get a technician to you without too many airline legs.

The DC electric fins made the most sense to me when I was looking to purchase, especially since I have experience with DC electrics and almost none with hydraulics.

If you are mostly trying to tame the boat in a rolly anchorage, you should really consider flopper stoppers, especially since you have a nice boom on your vessel already.

Good luck and keep us posted.

I have thought about flopper stoppers, but since I don't have a mast onboard that option went out the window. Am very curious to hear from people who have them to find out how well they can keep the boat calm in the anchorage. However then you will need towed fins to create some stability while underway.

I cannot comment on maintenance or problems of hydraulic stabilizers, however I can envision them. Same is with pneumatic systems, but since there is so much equipment necessary to work flawless in order for the stabilizers to work perfect.........and having worked with pneumatic systems in the past, I do know there is a lot that can go wrong.
Most fin stabilizers have some sort of shaft sticking out, through the hull, to which the fin is connected. That does mean that if you hit something that shaft can be damaged and now your fins may not work anymore.

Gyros most likely won't have a lot of problems. It is a closed system and if that is built well it will keep working. If you ever have a problem it is most likely to be an electrical problem. That could be a cooling problem or as I wrote before, it is not having enough juice available to power the gyro.
But a big draw back, at least to me, was the fact it needs a total rebuild every 3000 - 5000 hours. We spend about 9 months per year on the boat, which is around 6500 hours. Most of those hours we are on anchor, which means we will get to those 3000 or even 5000 hours every single season, perhaps even twice per season.
The running cost of a gyro are already staggering, but now I have to add 1 or 2 complete rebuilds per year to that as well ? That is too much for me..

As for the electrical fins I did like the fact that maintenance is minimal. The motor unit is self contained and is completely sealed. It is powered with 220 V AC (at least mine are) and there is not a lot that can go wrong with the motor. I spoke with several charter boats that have electrical fins already for 5 years and they had not had a single motor failure.
If you hit something in the water, e.g. a log or container, the fin will be ripped off, it is designed to break off. Then you will have to bolt a new fin to the motor and off you go.
What I will need to do is change the outer seals every 5000 hours, but after I spoke with the producer of the stabilizers they agreed that I can postpone it until the end of the season when the boat is coming out of the water anyway. And changing the seal will take half a day apparently, I can live with that since it keeps the costs down. As stated before the operating costs are minimal, which I also like.


Every stabilizer will have a control box and most important part with those boxes is to keep them cool. That means cleaning the air filters and making sure the small ventilators (same ventilator as any computer has) function well.

And then there is the issue of who is going to do the maintenance. Most producers do have an extensive service network, where you can make a difference between companies that are allowed to do installations (plus repairs after damage) and companies that can only do standard maintenance.
It is definitely something to take into consideration when you decide on a stabilizing system, especially when you know you will have to do a lot of standard maintenance on the system. With that in mind also check how long the warranty period is and what is in- and excluded.
In my case there are enough service stations around in the Med where I can go to if something goes wrong.
 
My biggest regret in my boating career is selling my Ocean Alexander 456 that had ABT Trac stabilization.

I have been looking for a monohull in the Mediterranean, and have found two Grand Banks 42 foot boats that have hydraulic stabilization.


If you want another Ocean Alexander, there is one for sale in Spain. Will require work on 1 engine, but is stabilized, she looks great.

https://www.devalk.nl/nl/jachtmakelaardij/808559/OCEAN-ALEXANDER-MARK-1-PILOTHOUSE.html
 
I have thought about flopper stoppers, but since I don't have a mast onboard that option went out the window. Am very curious to hear from people who have them to find out how well they can keep the boat calm in the anchorage. However then you will need towed fins to create some stability while underway.

Not having a mast complicates things a little, but it's likely still possible to engineer a flopper stopper setup. Especially if you're only intending to use it for no-power stabilization at anchor and not for paravanes when underway, as the at-anchor structural loads are typically lower.
 
Perhaps the solution is on this website. Look at the all-in-one., works also at anchor.

https://dmsholland.com/for-who/yacht-owners[/URL]

Good luck,

Paul
 

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