Best Autopilot for a Hydraulic system on a sailboat

[SV Windrush II]

Hello all. We have been refitting our Hudson Seawolf 44 CC ketch and getting ready to install a new autopilot. It has no existing autopilot so this will be new system.
The boat does have a very good hydraulic system with pneumatic assist.
I am looking for advice on the best autopilot out there that can be installed with my current hydraulic system and hopefully keeping my existing hydraulic ram on the rudder. This is a 14.5 ton boat with a full keel. Thanks

[rslifkin]

Based on the mention of air pressure, I'm assuming you have a Hynautic steering system? Any autopilot that supports a hydraulic reversing pump drive will work, you just need a pump sized for an appropriate hard-over time with your existing steering cylinder and that supports the 3 line system connection (most pumps do).

[SV Windrush II]

Originally Posted by rslifkin

Based on the mention of air pressure, I'm assuming you have a Hynautic steering system? Any autopilot that supports a hydraulic reversing pump drive will work, you just need a pump sized for an appropriate hard-over time with your existing steering cylinder and that supports the 3 line system connection (most pumps do).

Yes it is a Hynautic system, thanks, I just couldn't remember the word for it!

[deblen]

Most modern autopilots will steer any boat if the hydraulic pump is sized correctly-as RS Lifkin says-the pump must be able to easily pump enough cu. in. per second/minute to fill/empty your existing ram within 10-20seconds or so.
Suggest you determine the volume of your current ram.
Then find a reversing pump that can easily pump the required volume.
The brand doesn't matter. Any pilot will drive any pump.
Strongly suggest you study up on this hard over time calculation.It will determine successful (or poor) pilot performance.When you have learned enough about this,strongly suggest you find a highly recommended marine hydraulic guy & double check with him.
When you have the hydraulics sorted,pick the autopilot of your choice,keeping in mind that the pilot port,stbd & clutch terminals must be capable of putting out enough current to drive the pump hard against the mechanical rudder stops.
Some pilots require an intermediate "drive box" to achieve this.
Another choice is a constant running pump with built in/on solenoids that require less pilot output current-but draw more amp-hrs from your sailboat battery
A third option is Raymarine M81131,M81132 electric ram.
One more thing: Having installed many pilots in my working days,I found that an analog rudder angle meter was a huge advantage in setting up the pilot ,making performance adjustments in daily use and showing problems when they inevitably occur.A digital bar graph doesn't hold a candle.


Just my personal experience from installing & using.
Cheers/Len

[stormalong]

An alternate viewpoint:

Based on having once met a sailor that had to use an emergency tiller to hand steer for over a week due to a hydraulic failure.

Use a mechanical drive on a separate tiller arm for your autopilot. If the hydraulics fail you still have a way to steer the boat.

I have a standard Edson pull-pull steering system. Once, on the way to Bermuda the chain broke. I steered through St. Georges cut and was able to anchor on autopilot. Done with the permission of Bermuda customs. I then replaced the chain and proceeded to check in.

If your hydraulics fail your hydraulic autopilot fails with it.

[rslifkin]

Originally Posted by stormalong

An alternate viewpoint:

Based on having once met a sailor that had to use an emergency tiller to hand steer for over a week due to a hydraulic failure.

Use a mechanical drive on a separate tiller arm for your autopilot. If the hydraulics fail you still have a way to steer the boat.

I have a standard Edson pull-pull steering system. Once, on the way to Bermuda the chain broke. I steered through St. Georges cut and was able to anchor on autopilot. Done with the permission of Bermuda customs. I then replaced the chain and proceeded to check in.

If your hydraulics fail your hydraulic autopilot fails with it.

A separate mechanical drive won't work with Hynautic steering unless you open the hydraulic relief valves every time you want to use the autopilot. The system is check valved to prevent the rudder from back-driving the wheel, so you won't be able to move the rudder with a separate non-hydraulic autopilot drive until you open the relief valves to allow fluid to flow freely back to the reservoir.

A separate drive as a backup is fine, but not as a primary autopilot drive with hydraulic steering.

[SV Windrush II]

Originally Posted by stormalong

An alternate viewpoint:

Based on having once met a sailor that had to use an emergency tiller to hand steer for over a week due to a hydraulic failure.

Use a mechanical drive on a separate tiller arm for your autopilot. If the hydraulics fail you still have a way to steer the boat.

I have a standard Edson pull-pull steering system. Once, on the way to Bermuda the chain broke. I steered through St. Georges cut and was able to anchor on autopilot. Done with the permission of Bermuda customs. I then replaced the chain and proceeded to check in.

If your hydraulics fail your hydraulic autopilot fails with it.

I have a quick disconnect on my hydraulic ram and a emergency tiller ready to install, but you are right i will obviously loose my autopilot at that point. I will be bringing backup hydraulic parts and hoses in case it fails also.

[mvweebles]

Any autopilot will work. B&G might have sail specific controller such as sail to wind. For sizing, you need to figure out the capacity of your hydraulic ram.

You don't need to go with the OEM pump, just make sure you get either a 2-wire or 3-wire pump depending on the OEM brand. I have run an Octopus pump for a while.

BTW - to deploy mechanical emergency tiller, a mechanical quick disconnect for the ram works, but most boats have a crossover valve between the two hydraulic lines into the ram that is opened to provide an open loop path

[s/v Jedi]

I have the B&G pilot driving a Hynautics hydraulic system and it works great. B&G has the features for sailboats and comes from the legendary Robertson autopilots.

[MIRELOS]

I've had Furuno on my 60' cat for 12yrs, no issues, handled all sea states and great tech support (was mounted incorrectly at the factory and had to go to factory reset)

[s/v Jedi]

Originally Posted by MIRELOS

I've had Furuno on my 60' cat for 12yrs, no issues, handled all sea states and great tech support (was mounted incorrectly at the factory and had to go to factory reset)

But can it sail to a wind angle, tack and jibe?

[rslifkin]

Originally Posted by s/v Jedi

But can it sail to a wind angle, tack and jibe?

Yes, the modern-ish Furuno pilots have those features.

[s/v Jedi]

Originally Posted by rslifkin

Yes, the modern-ish Furuno pilots have those features.

That’s great, I think Furuno is a very good option then. Much depends on what other electronics a boat has, because the B&G pilot doesn’t require a control unit when you have their plotter or Triton display and keypad.

[pcmm]

Originally Posted by s/v Jedi

But can it sail to a wind angle, tack and jibe?

My older Raymarine AP can also do this. Activating the AP to steer to wind is done by pressing "standby" and "Auto" together. tacking is accomplished by pressing "+1 and +10" or "-1 and -10" together. Jibe is a good one. not sure that is a maneuver I would want the AP to do for me. All of this on a system that uses the old Seatalk bus!

Of course you need to have the rest of the instrument package connected so that it has that information on the bus to work with!

[s/v Jedi]

Originally Posted by pcmm

My older Raymarine AP can also do this. Activating the AP to steer to wind is done by pressing "standby" and "Auto" together. tacking is accomplished by pressing "+1 and +10" or "-1 and -10" together. Jibe is a good one. not sure that is a maneuver I would want the AP to do for me. All of this on a system that uses the old Seatalk bus!

Of course you need to have the rest of the instrument package connected so that it has that information on the bus to work with!

Yes, this is from it’s Autohelm ancestry