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Old 10-17-2014, 11:24 PM   #21
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I think the confusion is that you have two different situations, with two different answers.

Stabilizers don't require a lot of hydraulic power, so operating off a main engine driven pump works fine. It could be either fixed displacement or variable displacement, with the later being more elegant and more expensive. Powering off the main engine removes the need to run the generator all the time, which I think is what you are hoping to accomplish.

The other situation is docking when you want to use your thrusters. Thrusters use significantly more power than stabilizers, and powering them off the main engine is likely not practical. The problem is that when docking your main is at idle, so to get enough flow for the thruster you need a really big pump. Engines and transmissions have limits on how big a pump you can put on them, and that will typically not be enough for good thruster performance. The common solution is to put the pump on an engine that's running at 1800 RPM or more instead of 600 RPM, so that means the generator or a wing engine if you have one. The ideal setup would have the biggest pump that will fit on the main engine to run the stabilizers underway, and to provide partial power to the thrusters while at idle. Then a second pump on the generator (I'll assume no wing engine, but it could go there as well) to provide the additional power needed for full thruster performance.

Now all this really depends on the specifics of your boat. How big is your main engine, how big a pump can it take, what's it's idle RPM, how much power do your thrusters require, and how much more is needed than your main can provide?
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Old 10-18-2014, 03:14 AM   #22
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My engine-driven hydraulic pump runs continuously without a clutch and has done so for 19 years.
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Old 10-18-2014, 07:31 AM   #23
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I think the confusion is that you have two different situations, with two different answers.

Stabilizers don't require a lot of hydraulic power, so operating off a main engine driven pump works fine. It could be either fixed displacement or variable displacement, with the later being more elegant and more expensive. Powering off the main engine removes the need to run the generator all the time, which I think is what you are hoping to accomplish.

The other situation is docking when you want to use your thrusters. Thrusters use significantly more power than stabilizers, and powering them off the main engine is likely not practical. The problem is that when docking your main is at idle, so to get enough flow for the thruster you need a really big pump. Engines and transmissions have limits on how big a pump you can put on them, and that will typically not be enough for good thruster performance. The common solution is to put the pump on an engine that's running at 1800 RPM or more instead of 600 RPM, so that means the generator or a wing engine if you have one. The ideal setup would have the biggest pump that will fit on the main engine to run the stabilizers underway, and to provide partial power to the thrusters while at idle. Then a second pump on the generator (I'll assume no wing engine, but it could go there as well) to provide the additional power needed for full thruster performance.

Now all this really depends on the specifics of your boat. How big is your main engine, how big a pump can it take, what's it's idle RPM, how much power do your thrusters require, and how much more is needed than your main can provide?

Thanks TT...that explanation helps a lot. I am going to look into the cost of that set-up.
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Old 10-18-2014, 07:32 AM   #24
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Thanks to all for the info. It's amazing how much you can learn on this forum...and how quickly.
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Old 10-18-2014, 07:51 AM   #25
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One more question...which I think I already now the answer to. Do I need to have the stabilizers ON or CENTERED continuously when underway? I think the answer is YES...and both conditions require the hydraulic pump and generator (on this boat) to be running. What happens if the stabilizers are turned off underway?
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Old 10-18-2014, 08:01 AM   #26
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First of all what brand/type/model of stabilizers are these? Various makes and designs work different ways. Lots of wild jumping to conclusions here with scant information. For instance if they are standard Naiads, then yes, you should have them on all the time, centering is for docking. Naiad is very helpful and could advise on the conversion. In theory (again lacking good info) having the thruster on the generator and the stabilizers on the genset makes the most sense.
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Old 10-18-2014, 08:04 AM   #27
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Greetings,
Mr. MM. To the best of MY knowledge, stab's should be on while underway (if centered, I don't think they'd be doing much if anything) and centered while slow maneuvering (if on while slow maneuvering it really screws up where you want the boat to go-don't ask me how I know this). Our Naiads are powered by a two belt pump run off the front of our port Lehman-no clutch).
Our Naiads have pins to lock the stab's in a centered position when off. I hate to think what would happen if we engaged the stab's with the pins in place so I usually leave the pins out.
Rats, Mr. C beat me by 3 minutes...
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Old 10-18-2014, 08:10 AM   #28
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We expect to travel from Virginia to Florida each winter, so we will put some miles on the boat. This set-up doesn't sound very fuel efficient to me. If I get between 3 and 4 NMPG without the generator, why would I want to increase my fuel consumption by 50 to 75 percent? Is there any other benefit besides getting more time on the genset?

I guess I should have been clearer in my original post. I really think I want to move the hydraulic pump to the main engine. Any idea of the cost to do that?
Your Genset in most cases would not be burning 50-75% what your mains are.

The only change I would consider making is to run the stabilizers off the main/s. And I would put a PTO on both engines if you have twins. Or you could perhaps run the stabilizers off a DC hydraulic power pack if you can find one with the correct flow and rated for continuous duty. But if that gives you sticker shock then don't worry about it. You will how ever have to lighten or eliminate entirely the AC load on your Genset when you go to use your thruster.

If you have any questions on switching to engine driven PTOs, call Justin at TRAC +1 (954) 253-8047 or Burt at ABS Hydraulics (954) 593-3727
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Old 10-18-2014, 08:13 AM   #29
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What happens if the stabilizers are turned off underway?
They can flop around and cause drag and steering issues. If you loose the Genset or hydraulic power you would need to manually lock/pin them in the center position.
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Old 10-18-2014, 08:14 AM   #30
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Your Genset in most cases would not be burning 50-75% what your mains are.



The only change I would consider making is to run the stabilizers off the main/s. And I would put a PTO on both engines if you have twins. Or you could perhaps run the stabilizers off a DC hydraulic power pack if you can find one with the correct flow and rated for continuous duty. But if that gives you sticker shock then don't worry about it. You will how ever have to lighten or eliminate entirely the A/C load on your Genset when you go to use your thruster.



If you have any questions on switching to engine driven PTOs, call Justin at TRAC +1 (954) 253-8047 or Burt at ABS Hydraulics (954) 593-3727

Thanks for the info CAPT. I'll give them a call.
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Old 10-18-2014, 08:18 AM   #31
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They can flop around and cause drag and steering issues. If you loose the Genset or hydraulic power you would need to manually lock/pin them in the center position.

Got it. Thanks.
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Old 10-18-2014, 08:41 AM   #32
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First of all what brand/type/model of stabilizers are these? Various makes and designs work different ways. Lots of wild jumping to conclusions here with scant information. For instance if they are standard Naiads, then yes, you should have them on all the time, centering is for docking. Naiad is very helpful and could advise on the conversion. In theory (again lacking good info) having the thruster on the generator and the stabilizers on the genset makes the most sense.

They are Wesmar stabilizers and a Wesmar twin prop bow thruster.
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Old 10-18-2014, 08:58 AM   #33
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Then you should be talking to Wesmar about the issues, then have them refer you to someone in the area who can come take a look at the exact set up. Everything you've got here from us has been pure speculation, almost none of it very useful.
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Old 10-18-2014, 09:02 AM   #34
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Good Morning Xsbank
Would love to see some pictures of your set-up and a little more info if possible.
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Old 10-18-2014, 09:06 AM   #35
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Our Naiads have pins to lock the stab's in a centered position when off. I hate to think what would happen if we engaged the stab's with the pins in place so I usually leave the pins out.
Nothing very bad happens. The pins are only for when you are servicing the units, such as the three or four year seal replacement. I once had a yard forget to remove the pins after servicing. Once I figured out what happened, diagnosing pulling them out in a seaway was not very fun, hate to imagine doing it in a cramped space; thank God they were accessed via stand up, spacious engine rooms.
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Old 10-18-2014, 09:09 AM   #36
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Then you should be talking to Wesmar about the issues, then have them refer you to someone in the area who can come take a look at the exact set up. Everything you've got here from us has been pure speculation, almost none of it very useful.
George is right, call Wesmar first.

Or these folks: Wesmar Bow Thrusters, Stern Thruster, Stabilizers, Sonar, Hydraulic Systems Distributors
I was in under the impression you had TRAC stabilizers.
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Old 10-18-2014, 09:26 AM   #37
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ABT is American Bow Thruster
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Old 10-18-2014, 10:13 AM   #38
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They are Wesmar stabilizers and a Wesmar twin prop bow thruster.
We never pin our Wesmars, except when hauling out. We do not run our stabilizers all the time. They always re-center when switched off (to pin position) and do not flop around as some intimate. If a hydraulic ram is leaking yes, movement when off could occur, but a hydraulic leak or ram problem would be noted and fixed presumably.

Since new (10 years) there have not been any stabilizer issues and this includes heavy weather operation. The lip seals have been replaced and serviced twice since new. Wesmar is located in the PNW. But I've heard bad things about all stabilizer mfrs., so it depends on issue and knowledge of owner/mechanic to insure happy times.
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Old 10-18-2014, 10:37 AM   #39
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We never pin our Wesmars, except when hauling out. We do not run our stabilizers all the time. They always re-center when switched off (to pin position) and do not flop around as some intimate. If a hydraulic ram is leaking yes, movement when off could occur, but a hydraulic leak or ram problem would be noted and fixed presumably.

Since new (10 years) there have not been any stabilizer issues and this includes heavy weather operation. The lip seals have been replaced and serviced twice since new. Wesmar is located in the PNW. But I've heard bad things about all stabilizer mfrs., so it depends on issue and knowledge of owner/mechanic to insure happy times.

Thanks...that is good to hear.
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Old 10-18-2014, 11:21 AM   #40
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We never pin our Wesmars, except when hauling out. We do not run our stabilizers all the time. They always re-center when switched off (to pin position) and do not flop around as some intimate. If a hydraulic ram is leaking yes, movement when off could occur, but a hydraulic leak or ram problem would be noted and fixed presumably.

Since new (10 years) there have not been any stabilizer issues and this includes heavy weather operation. The lip seals have been replaced and serviced twice since new.
Yes they recenter when powered off or when you hit the center button. But unless they are pinned they can move around once/if you loose hydraulic pressure. Hence the reason for the pins. Some systems will center the fins below a set speed so they will not interfere with your steering when docking.
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