Next message: klysmi: "[world-cruising] Re: Hydraulic steering"
As an addition to Brian's answer: The combination of hydraulic steering and a windvane asks for some attention. I am referring to a windvane with a separate auxiliary rudder, driven by a pendulum, or just by the wind. I don't know if windvanes exist that can operate on a hydraulic steering wheel.
Most systems on regular yachts have one, double-action hydraulic cylinder.that directly moves the rudder-arm. The characteristic of such a cylinder is that it leaks a tiny bit of oil from the left space of the piston (the moving part inside the cylinder) to the right space and vice versa. No big deal, there is no mess cause all oil stays inside the cylinder, there is only the fact that the wheel needs to be turned (or the hydr pump to be operated) to stay on course and the wheel get's in another position next time the rudder is amidships.
Now you're using the windvane...
Imagine you're sailing for several hours and there is constantly some pressure (sideways) on the rudder. Cause of that pressure there is a force pushing the piston away and in time the oil-leakage I mentioned let's it move a bit. After some time the rudder will take another position and the windvane has to increase it's steering to compensate. After some more time you're sailing with the handbrake on... The main rudder steering to port and the windvane steering to starboard... or the other way around.
So, concluding: when a windvane is installed on a ship with hydraulic steering, there is a need for a mechanical fixation of the rudder-arm to be operated from the cockpit. This fixation will have to be sturdy cause it will deal with real forces.
When you want to know how I solved this on my boat, email me off list.
Hope this helped...
Fair winds,
Len
S/v Present
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