Hydraulic Pump Question

[Tom.B]

I already have a hydraulic pump on my Perkins 130hp engine that runs the stern thruster. Could the same pump also be leveraged for other tasks as well? Would this single pump run, say... a bow thruster too?

Tom-

 

[psneeld]

Really depends on what it can supply and whatever you add demands in psi and flow.

I would say yes to a lot of different useful boating tools...just maybe one at a time.

If it runs a big stern thruster..it should run a bow thruster, possibly a windlass, mast winches, capstans for mooring, air compressor....there are even kitchen tools that run off hydraulics/compressed air I believe that the Amish buy because they don't use electricity in the home (well at least the last time I visited Lancaster, Pa)

 

[Tom.B]

I assume there are different size pumps? Not sure where to look for specs or how to interrupt what I find.

Our stern thruster is not very big. I *hope* that someday soon we can add a bow thruster without having to go electric, thus, utilizing the current hydraulic pump. And by the looks of your post, Scott, maybe a hydraulic blender too

 

[caltexflanc]

Tom, there are some good hydraulic shops around the area might be able to advise you. Carter's in MHC comes to mind. There is a place in Raleigh I have bought parts from that serves the heavy equipment market, name escapes me at the moment, but there are a bunch of them up there. You could call one of those places and perhaps they could walk you through how to figure out what you have. Edit: name of the place is Motion Industries, they were very helpful finding an obscure part.

Yes, pumps come in all sizes. What is used on your stern thruster is quite different from that used on say, Caterpillar D9. My Naiads have a Vickers pump that is only big enough for that purpose; I suspect, but don't know, that the same applies to your thruster.

 

[psneeld]

I can imagine a hydraulic blender can REALLY make some smooth drinks...I'm sure RT Firefly has a couple of gas powered blender pix.

Maybe you can see what the hydraulic motor requires on your stern thruster and just not exceed it's rating if you can't track anything down about the pump.

 

[jleonard]

I have a Dickson stern thruster on my boat (installed by the previous owner). I was told by Dickson, that if I wanted to add a bow thruster I would have to upsize the pump because I would likely be running them both at the same time and the existing pump would be too small.
I would have to saythat made sense, as the stern thruster really has all it can do to move the boat sometimes.
After owning the boat for 6 plus years, I got used to the stern thruster and don't really have a need for an additional bow thruster.

I never seem to have enough ice aboard to warrant a hydraulic blender.

 

[Tom.B]

Good to know as I have the same thruster. THANKS!

 

[psneeld]

If you do want a bow thruster... there are plenty of situations where one or the other would help...but not necessarily both at the same time...a lockout or remote hydraulic valve to keep it all within limits maybe?

 

[Phil Fill]

I already have a hydraulic pump on my Perkins 130hp engine that runs the stern thruster. Could the same pump also be leveraged for other tasks as well? Would this single pump run, say... a bow thruster too?

Tom-

You can buy remote control hydraulic manifold that you can change the flow between the bow and the stern as the pump may not have the flow to operate both at the same time. You could buy a bigger pump provided you have the hp to drive a bigger pump and the hoses are strong enough.

I replaced the hydraulic pump with a Vickers variable flow/psi pump that is controlled from the pilot house. I can vary the flow/psi from 0 to 1800 psi from the pilot house. If I was going to install a stern thruster, I would install a remote controlled hydraulic manifold to switch between the bow and the stern thruster. The opening and closing of the valves is only a couple of seconds.

 

[FF]

Pumps come with SAE , std sized flanges.

IF an up sized pump is needed if its a bolt on no problem.

Spending the bucks for a bow thruster is a nice upgrade , but a hyd windlass or capstan might get more use.

of course if the hyd system is large enough a 4KW cruise generator is nice too.

 

[Tom.B]

Interesting. I might look into that, but just curious, what is a hydraulic cruise generator? An genset that provides AC power?

 

[jleonard]

If you do want a bow thruster... there are plenty of situations where one or the other would help...but not necessarily both at the same time...a lockout or remote hydraulic valve to keep it all within limits maybe?

A valid point that I considered but like I said after using the stern thruster I decided not to bother with a bow.
I think if I had both without a lockout it would simply run both together but obviously at a slower prop speed and switching one off would get the other to full speed.
All in all it might work out fine. Instead of pusing from the stern at full power you'd be pushing from each end with 1/2 power. Might be a wash with the added bonus of a little better control??

 

[Phil Fill]

Pumps come with SAE , std sized flanges.

IF an up sized pump is needed if its a bolt on no problem.

Spending the bucks for a bow thruster is a nice upgrade , but a hyd windlass or capstan might get more use.

of course if the hyd system is large enough a 4KW cruise generator is nice too.

You will need bigger than a 4kw gen set for power For hydraulic the engine hp is more important than kw. If single engine the gen set with a hydraulic pump can be connected for a get home. That is how the Eagle is set up, bow thrust and get home

 

[Tom.B]

A valid point that I considered but like I said after using the stern thruster I decided not to bother with a bow.
I think if I had both without a lockout it would simply run both together but obviously at a slower prop speed and switching one off would get the other to full speed.
All in all it might work out fine. Instead of pusing from the stern at full power you'd be pushing from each end with 1/2 power. Might be a wash with the added bonus of a little better control??

Yea... This is by NO MEANS a for sure thing. That $10k could do a ton more cool **** to Skinny Dippin' list before I ever get to where I would want to install a bow thruster. It's just on the "it would be nice" list, but I have been curious about the pump thing for quite a while now and actually thought about it when I had my laptop in front of me.

Thanks guys!
Tom-

 

[sunchaser]

I already have a hydraulic pump on my Perkins 130hp engine that runs the stern thruster. Could the same pump also be leveraged for other tasks as well? Would this single pump run, say... a bow thruster too?

Tom-

My guess is an electric bow thruster would be cheaper and run better than trying to use the existing pump. Too many older hydraulic pumps are undersized for idling work and require higher revs to run the higher HP bow thruster.

Interestingly, most newer Nordhavns use electric thrusters as hydraulic is too expensive and maintenance troubled. Lots of choices and debates but up to 15 HP electric seems the best bet - that is the way I went 3 years ago (eschewing the use of the port engine hydraulic pump) for better or worse.

 

[Bendit]

My guess is an electric bow thruster would be cheaper and run better than trying to use the existing pump. Too many older hydraulic pumps are undersized for idling work and require higher revs to run the higher HP bow thruster.

Interestingly, most newer Nordhavns use electric thrusters as hydraulic is too expensive and maintenance troubled. Lots of choices and debates but up to 15 HP electric seems the best bet - that is the way I went 3 years ago (eschewing the use of the port engine hydraulic pump) for better or worse.

I have to disagree. Pioneer came with a Vickers continuous flow vane pump (used to haul nets), and I fitted a hydraulic bow-thruster (Side Power 10hp) ) and a Nilsson hydraulic windlass. The overall cost was probably a little more than going electric - the Danfoss valve control unit was expensive - but I have had zero maintenance issues in 9 years of use.

It's great having that power available when hauling in a 30Kg anchor and 80 meters of chain. Similarly, the thruster can run continuously which is probably not necessary but nice to have. In fact we can run both simultaneously with no ill effects. All this happens at idle (700rpm)

However, if there was not already a large pump fitted to the main, I'd go electric to reduce costs.

 

[sunchaser]

I have to disagree.
However, if there was not already a large pump fitted to the main, I'd go electric to reduce costs.

I believe you agreed.

 

[Bendit]

I believe you agreed.

Perhaps I could have expressed myself a bit better.

If there is a hydraulic system present, I believe this is the way to go.

Pumps are not that expensive, so if there is a fluid tank, cooler, hoses and fabricated mounts for the pump, it is probably worth upgrading to a larger capacity pump to deliver the required flow at idle.

You refer to maintenance issues, this has not been the case in my experience.

But if starting from scratch, with no components already installed, hydraulic becomes a more expensive, and possibly uneconomic, option.

 

[FF]

The biggest hassle with HYd is to get real power RPM is required.

A pump has to be huge to produce enough power at idle , while docking.

Nordy used to "solve" this with monstrous complexity.

Pump on the main , pump on the gen set , pump on the wing engine.

Complex but when it all works the Nordy 602 here can short turn in her own length with ease.

"You will need bigger than a 4kw gen set for power"

4KW will run 2 air cond or most common cruise loads. the 40KW is always there if you want to run everything aboard at once.

 

[Phil Fill]

When we bought the Eagle it had a hydraulic boat thruster and get home with the hydraulic pumped powered by the gen set at 1800 rpm. The hydraulic pump had an electric clutch that can be turned on/off at the helm. I believe the boat came with the pump used for the get home, so previous owner added the bow thruster. However the PSI/Flow was max 1200 psi and with just the ON/OFF the sudden PSI which caused the belts to slip and the hose to jump, which caused me jump. So converted the pump to a variable/vane from 0 to of 2500 psi. That can now be controller from the helm, so the belts do not slip, the hoses do not jump, and I don’t jump.

Not satisfied with the performance of the bow thruster so went from a 6” pulley to 8” so the PSI went from 1200 psi to 1800 psi which improved the performance. Tried a 9” but it bogged down the engine resulting is the small max PSI/Flow as the 8”. The pump is rated at 2500 psi, the hoses are 3000 psi and the bow thruster 2300 psi. So the limiting factor is now the HP of the gen set. So if/when the gen set is replaced it will be sized by the engine HP not the KW. So the ultimate limiting factor will probable be the engine HP and RPM.