Gyro stabilizers

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Kent33

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Nov 28, 2024
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Hi, I’m a newbie here based across the pond on the East Coast of the UK. At the Southampton Boat Show I was interested by gyro stabilizers and wondered if anyone here has any experience of how effective they are in the real world?
 
A TF member @Hippocampus had a Seakeeper on his recently sold Nordic Tug 42. He loved it and by his reports worked well.

A common fault is undersizing the system due to expense so don't skimp on size.

I'm guessing you're aware of the tradeoffs - pretty well need a generator to spool up, and it takes time to get it going so it's best for full time generator boats. They are also difficult to retrofit into an existing boat. But the real world feedback I've heard has been fairly positive.

Peter
 
If you go into the history you will find several topics on stabilization. I wrote a bit of a pros and cons of each system about 2 years ago. We went through the same process as you are going through and before we took a decision I contacted most of the producers, spoke with them, spoke with users and in the end I decided what system we would install.
My demands were simple, I wanted stabilization under all circumstances which means underway, at anchor and even in port (if necessary).
In addition I did not want it to use a lot of electricity, I needed to be able to run it off the batteries (and solar during the day) and I wanted a system that would not be overcomplicated. Overcomplicated normally means more options to break down while on the water and I don't want to be in a storm, finding out that the stabilization failed because one simple hose starts leaking etc.

A gyro, if heavy enough, can be a very efficient system, it can and will stabilized the boat. When it comes to gyros it is all about the 'self righting moment' which means the gyro wants to stay in the position it was placed in. That can either by via a lot of weight and a lower RPM or via less weight, but a much higher RPM.
And in order for that gyro to keep the boat stable it needs to be attached to the boat, which can mean you will have to reinforce the hull and make sure that gyro cannot break off its supports. Any roll movement the boat makes will result in a opposing force by the gyro (which wants to stay upright) and that force goes into the hull.
That said, a gyro becomes less effective when the speed of the boat increases, so gyros are indeed at their best in low speed boats like trawlers.

There are a few things to take into consideration when you want to use a gyro. If you live on your boat, like we do most of the year, and you spend a lot of time on anchor a gyro may not be for you.
First and foremost there is the spool up time of the gyro, which can vary between 30 - 45 min and if you need stabilization quick (due to a sudden storm) you can forget about it, that is not going to happen.

Second is that the gyro does require a lot of energy and that means the generator needs to run all the time and also needs to have a lot of overcapacity. That is going to put hours on the generator quite quickly, resulting in a requirement for maintenance and of course there is the fuel usage of the generator. My generator uses 3 ltr of diesel per hour when it runs at 100 %, so having the gyro on for 24 hrs would result in 72 ltrs of fuel each day and in one month that could be 2100 ltrs. With the fuel prices in Europe that was a bit over the top.
Of course you can switch off the stabilization, but was is the point of having stabilization and not using it because the fuel cost are too high ?
Also, if you have a small generator, e.g. like the one I have which is a 6.5 Kva Onan, it would mean that I would lose half the available power of that generator to the gyro. That would seriously impact the way I can use the boat. In fact, I would have to start switching off equipment in order to run the gyro.
There is one other important factor about the generator and that is that I won't run a generator while I am asleep. That is just too dangerous, so that is a no no for me, but it would also mean I would never have stabilization at night, which does not make sense at all.

Third, there was the need for maintenance of the gyro, which truly shocked me. Seakeeper told me that I would have to change the bearings every 5000 hours and that would require a complete tear down of the whole sea keeper by an authorized mechanic. In order to do that I would have to empty my salon, remove all the sound proofing material from the ceiling in the engine room, just so that they would be able to gain access to the engine room with a hoist. Since we spend most of the year on the water, also mostly on anchor, we would get to those 5000 hours basically every year. Doing that type of maintenance was a no go item for us.
Recently there was a topic here about a Quick MC30 gyro and that one does not seem to need this maintenance, which would be an absolute positive point.

In the end it meant a gyro was not for us. I can however understand that, if you only use the boat a few times during the month and only anchoring in very well protected bays (where you don't need the stabilization) then a gyro can be good for you. Also, if you sail in an area where there are a lot of logs and other debris in the water you are better off with a gyro and not with fins. Don't know how it is in the area where you are sailing, but that might be one of your considerations.

So we choose to go for electric fins. They run at 220 V, use minimal electricity, don't use up a lot of space in the boat and I can have them on 24 hrs a day. If there is no disturbance in the water they are at rest, but the moment we would get hit by a wave or wake they immediately get into action and keep the boat stable. In one year we have put almost 6000 hours on them, this winter will be the first maintenance. I will have an official rep do that maintenance, so I can see and record what needs to be done and what to pay attention to. After that I will do the maintenance myself every year, there is not a lot that can go wrong. If the electric motor functions the fins will function as well.
 
So for completeness, we need to hear from someone with the Quick gyro and someone with hydraulic fins powered by the propulsion engine.

David
 
If you go into the history you will find several topics on stabilization. I wrote a bit of a pros and cons of each system about 2 years ago. We went through the same process as you are going through and before we took a decision I contacted most of the producers, spoke with them, spoke with users and in the end I decided what system we would install.
My demands were simple, I wanted stabilization under all circumstances which means underway, at anchor and even in port (if necessary).
In addition I did not want it to use a lot of electricity, I needed to be able to run it off the batteries (and solar during the day) and I wanted a system that would not be overcomplicated. Overcomplicated normally means more options to break down while on the water and I don't want to be in a storm, finding out that the stabilization failed because one simple hose starts leaking etc.

A gyro, if heavy enough, can be a very efficient system, it can and will stabilized the boat. When it comes to gyros it is all about the 'self righting moment' which means the gyro wants to stay in the position it was placed in. That can either by via a lot of weight and a lower RPM or via less weight, but a much higher RPM.
And in order for that gyro to keep the boat stable it needs to be attached to the boat, which can mean you will have to reinforce the hull and make sure that gyro cannot break off its supports. Any roll movement the boat makes will result in a opposing force by the gyro (which wants to stay upright) and that force goes into the hull.
That said, a gyro becomes less effective when the speed of the boat increases, so gyros are indeed at their best in low speed boats like trawlers.

There are a few things to take into consideration when you want to use a gyro. If you live on your boat, like we do most of the year, and you spend a lot of time on anchor a gyro may not be for you.
First and foremost there is the spool up time of the gyro, which can vary between 30 - 45 min and if you need stabilization quick (due to a sudden storm) you can forget about it, that is not going to happen.

Second is that the gyro does require a lot of energy and that means the generator needs to run all the time and also needs to have a lot of overcapacity. That is going to put hours on the generator quite quickly, resulting in a requirement for maintenance and of course there is the fuel usage of the generator. My generator uses 3 ltr of diesel per hour when it runs at 100 %, so having the gyro on for 24 hrs would result in 72 ltrs of fuel each day and in one month that could be 2100 ltrs. With the fuel prices in Europe that was a bit over the top.
Of course you can switch off the stabilization, but was is the point of having stabilization and not using it because the fuel cost are too high ?
Also, if you have a small generator, e.g. like the one I have which is a 6.5 Kva Onan, it would mean that I would lose half the available power of that generator to the gyro. That would seriously impact the way I can use the boat. In fact, I would have to start switching off equipment in order to run the gyro.
There is one other important factor about the generator and that is that I won't run a generator while I am asleep. That is just too dangerous, so that is a no no for me, but it would also mean I would never have stabilization at night, which does not make sense at all.

Third, there was the need for maintenance of the gyro, which truly shocked me. Seakeeper told me that I would have to change the bearings every 5000 hours and that would require a complete tear down of the whole sea keeper by an authorized mechanic. In order to do that I would have to empty my salon, remove all the sound proofing material from the ceiling in the engine room, just so that they would be able to gain access to the engine room with a hoist. Since we spend most of the year on the water, also mostly on anchor, we would get to those 5000 hours basically every year. Doing that type of maintenance was a no go item for us.
Recently there was a topic here about a Quick MC30 gyro and that one does not seem to need this maintenance, which would be an absolute positive point.

In the end it meant a gyro was not for us. I can however understand that, if you only use the boat a few times during the month and only anchoring in very well protected bays (where you don't need the stabilization) then a gyro can be good for you. Also, if you sail in an area where there are a lot of logs and other debris in the water you are better off with a gyro and not with fins. Don't know how it is in the area where you are sailing, but that might be one of your considerations.

So we choose to go for electric fins. They run at 220 V, use minimal electricity, don't use up a lot of space in the boat and I can have them on 24 hrs a day. If there is no disturbance in the water they are at rest, but the moment we would get hit by a wave or wake they immediately get into action and keep the boat stable. In one year we have put almost 6000 hours on them, this winter will be the first maintenance. I will have an official rep do that maintenance, so I can see and record what needs to be done and what to pay attention to. After that I will do the maintenance myself every year, there is not a lot that can go wrong. If the electric motor functions the fins will function as well.
If I remember correctly you have the CMC waveless system. What was the cost roughly.
thanks,
Bud
 
So for completeness, we need to hear from someone with the Quick gyro and someone with hydraulic fins powered by the propulsion engine.

David
I have the Naiad hydraulic fins on a 49 GB. They work well, but the system is old. I have replaced the rams, the hoses and the feedback units so they do not leak (not totally true, small leak around hydraulic tank). There is an electronic upgrade available that I am considering but want to explore other options. I would say for negatives there are a lot of moving parts, Starboard engine has to be running for them to operate due to hydraulic pump. Takes up a lot of space in engine room. Difficult to make adjustments if needed. Outside fin seals are not as robust as I would like.

Bud
 
I am doing an install on a Quick Gyro this winter and have my progress post going on now.
Look up "Quick Gyro "

As far as effectiveness 100% as long as sized properly. Both companies while sizing give you two options. Go with the bigger one.

Things to consider about any of the systems.
1. Yearly Maintenance Costs and by Whom. Self or dealer.
2. Run time. Seakeepers must be ran at all times under way. (few people know that) , In a minimal power mode. So a genset is required at all times underway. A Quick does not . It can be left off while moving.
3 New fin systems and fin type systems that do have the ability to stabilize at rest.. They have external parts that can snag or tangle. Some have very expensive maintenance routines.
4. costs of the purchase and installation of the systems.
5 Power consumption. Quick spins slower. Quick Uses more power. So available power consumption is a real consideration. Both have reduced power mode. I had a Seakeeper on my last boat. At anchor reduce power mode was fine. Open water full power was a must.
6 fins I also have. Hydraulic type. Fine under way but do not work at rest. No power required and run off the main engines. No real cost to running underway. They do have pumps, valves, external seals all requiring maintenance. Last year my seals and bearing to the fins I changed , around 3k but I did the work. Days of labor. So Math that out at mechanics rates.
 
Thanks everyone, really appreciate your replies. I’ll look up the threads mentioned and follow the Quick installation thread as that’s the make I got interested in at the show.
 
If I remember correctly you have the CMC waveless system. What was the cost roughly.
thanks,
Bud
I could have gone for the Stab 20, but took the Stab 25, which is a bit more expensive. Going for 1 size larger was a tip from some other boaters, they had found out that their hydraulic fins were a size too small, did not perform well in rough weather. So that is why I decided for one size larger.
Later I was told that this does not apply to electric fins since they can react much faster and with a smaller fin that would have been the solution. However, it would have meant more electricity usage and that is not what I was looking for. I now use about 10 Amps per hour (at 24 V) while at anchor and maybe 20 Amps per hour while underway. Since I have 1400 Ah in my batteries I can run them all night long without even worrying if I make it through the night. While underway the alternators will easily supply all the power.
Total was around 70.000. If I would have taken the stab 20 it would have been around 10.000 cheaper. And that is excluding the charge for the lift out and the marina space. Installation takes about 15 - 20 days.
Process is simple, first they drill a hole in the boat where the motors should come. After that they will reinforce the hull in that area. Once that is done they will install the motors and finish up sealing off the holes.
When all of that is finished the electricians show up and pull all the cables, install the control boxes and the gyro (just a small one that will measure the rolling of the boat). I took the 220 V version since I can easily run them off my inverter (Victron Quattro 24 8000 200)
Once installed it will take about 1 day to set up all the parameters and do the sea trial to fine tune the set up.
After that you are ready to go.
And like I said, we use them basically 24/7, so underway, at anchor and even in the port. There is no need to switch them off, since they don't use any electricity if they don't need to do anything.

One other benefit is that these fins are just bolted onto the motors. If you hit something in the water or get tangled into a rope the fins will just break off and float. They are made of epoxy resin, so are also lightweight. You can pick them up, call the service center, they will either fit a new fin or fetch yours up and put it back on. Unlike in the hydraulic fins there are no poles sticking out of the hull.

Maintenance cost is an issue and it depends a bit to whom you go. Basically it comes down to changing some seals and change some grease in the motors. If you let the company from Italy do it you may as well buy a complete new stabilization system, they go absolutely beserk with the prices. But if you contact one of their reps you get a much more civilized price. Maintenance is about 1.5 days work, the seals are about 700 euro, the bolts are about 400 euro (16 in total) all the rest is labor. Like I said, I will have an official rep do it this time, then I will put it on video and next time I will do it myself. I always say: I used to fly planes, so I should be able to learn this as well.
 
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I'm the distributor of Mitsubishi/ARG Gyro stabilizers in Turkey. There are many thing to tell about the gyro stabilizers, but the most important thing is they don't work efficiently on stable boats . I meaned, they work great in unstable yachts like Flybridge motoryachts, planning boats, or RPH Explorers but doesnt work well on stable boats like displacement trawlers or semi displacement sedan trawlers.
If GMtransverse value is bigger, that means the boat is stable boat and much more torque is needed to handle the rolling.
If GMtransverse value is lower, that means the boat is unstable boat but it requires less torque to handle and gyro stabilizers can easily stop rolling.
 
Hi, I’m a newbie here based across the pond on the East Coast of the UK. At the Southampton Boat Show I was interested by gyro stabilizers and wondered if anyone here has any experience of how effective they are in the real world?
Congratulations on your boat. I know the area intimitately. It all depends on you chosen cruising grounds. With a boat like yours and using the wind over tide predicitions you don't really need them unless you have major crossings and a tight schedule in mind.
 
but the most important thing is they don't work efficiently on stable boats
It's obvious when you think about it, but this is the first time I have seen this in print. Thanks @Peloga!
 
Thanks everyone, really appreciate your replies. I’ll look up the threads mentioned and follow the Quick installation thread as that’s the make I got interested in at the show.
You might consider a DMS Magnus Effect system: Deploys in 12 seconds, uses 12V or 24V. The downside is that you must be underway for the system to be effective - a minimum of 3 knots and a maximum of 12 knots. The system deploys a round tube which is spun by an electric motor to counter rolling - it is very effective with low maintenance, almost immediate deployment, very low power consumption (with no need to run a genset). It is also very flexible in terms of where it is placed in a boat and requires very little space.
 
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