Lets talk Hydraulics

[Matt sachs]

After discovering the bow thruster I want needs 800 amps, Im considering hydraulics to power the bow thruster, scuba compressor and port side windlass. Sidepower has what looks like a nice set up for up to six different hurdaulic motors. Any ideas or input about hydraulics on a boat? Im not new to hydraulics, but in a marine environment what issues do I need to address? Any input is welcome.

[Blue Stocking]

What would you use, constant running pump loop system with solenoid spool valves for the various rotations required ?

[a64pilot]

Not sure I'd want to run a Scuba compressor off of hydraulics, that would require quite a large system and brings in cooling into the equation. Your other requirements are short time use and therefore shouldn't have cooling issues I wouldn't think.
What's going to drive the hydraulic pump? I assume main engine?

[Matt sachs]

Side power has a variable out put pump. Its a load sensing pump that I can bolt on to the pto of the transmission. And Ill design the system so that each circuit requires about the the same flow. This way I'll know that if Im using the hyrdaulics, the engine needs to be at certain RPM regardless of which system is in use.

[Lancerbye]

Having set up my own hydraulic system on a commercial fishing boat, many years ago I have to admit that I miss having it on my pleasure craft. You would need a electric clutched hydraulic pump, running off the engine, a reservoir and the equipment with controls that you want to use. Other uses that I have seen on pleasure boats are: windlass, water maker, emergency high volume water pumps. It is a very versatile energy source. You can use the metal free hydraulic hose with reusable fittings, available at commercial fishing supply stores.

[Matt sachs]

Direct Drive PTO for Twin Disc and ZF Marine Style Transmissions I like the idea of a mechanical PTO that can be disenguaged instead of an electric clutch. My tractor is up this way and it works great. Maybe not the same brand that I linked to, but something like it.

[a64pilot]

Actually a variable flow, constant pressure pump would only require that the engine be run fast enough, a little faster than min wouldn't hurt at all.
You have a PTO? That makes it much more viable I think

[Matt sachs]

I plan to have a PTO. The engine room is a blank canvas at this point. The boat (except the engine room) is 90% complete. The engine room is going to be the real money pit. I have come to far to cheap out now...

[Matt sachs]

Originally Posted by a64pilot

Not sure I'd want to run a Scuba compressor off of hydraulics, that would require quite a large system and brings in cooling into the equation. Your other requirements are short time use and therefore shouldn't have cooling issues I wouldn't think.
What's going to drive the hydraulic pump? I assume main engine?

Good point. The side power hydraulic tank is water cooled with a circulation pump. I didnt really think about run time for the compressor....hummm.

[Wind River]

I have toyed with this idea for a while for all of the same reasons and equipment you have mentioned, including the dive compressor. I am also looking to add engine drive refrigeration to the mix.

I am considering auxiliary diesel engine to use as a DC generator, power a water maker and power a hydraulic pump for all the other systems. Emergency high volume bilge/trash pump is a idea I didn't think of. I like it.

Please let us know how this works out for you.