I have a champagne taste with a beer budget. My 70' aluminum hull motoryacht is not equipped with stabilizers. It is the one big deficiency I gripe about while cruising, but forget about when back at the dock. My cruise speed is between 8 to 10 knots depending on sea state, etc, and I prefer to anchor out most of the time while cruising instead of jumping from marina to marina. I dream of zero-speed stabilizers, but I'd prefer spend less than the cost of a new installation. I imagine it is possible to find and install used stabilizers, but I worry that if they were pulled from another boat they will come with an array of issues and will need to be extensively rebuilt which would negate any "savings" advantage of buying used gear. Has anybody installed used stabs? What was your experience? Any advise or regrets?
I haven’t finish the installation but I got a set of Trac from Advantage Marine Service in FTL (local ABT Trac dealer). Fully rebuilt for a fraction of the cost. they were take out from a boat which upgraded theirs. We have zero speed Trac on the 110 I run. They help a little but not as good as gyro.
Had the recent thought to transition to a manifold addition of an AC pump to obtain zero speed capability. Is it worth the investment?
That’s what we have. I actually replaced and relocated the pump last year. When the gen PTO engages it also starts the march pump. the stab software needs to have the zero speed capability. It also requires bigger fins and actuators. as I said, it s not a miracle bullet. It doesn’t prevent the first roll that well but dampens the following rolls in the cycle.
I know it's not apples and apples, but approx what is your amp draw on the AC pump? (My PTO's are on both engines)
Amp draw is minimal. Maybe 2 or 3 amps. but if you need to run one of the mains to get hydraulic, cooling will be provided by the main. At least that’s how our Trac work. We only run the electric pump when running the zero speed on the stbd gen. (Port gen doesn’t have a PTO)
I don't believe (top of my head) that the 20 kw NL gens can provide sufficient flow and pressure, so I think the electric is the way to go here, maybe convert the forward thruster to hydraulic and shift the DC Lewmar aft. Convert the controls and add the pump to the network, resolve the cooling (perhaps with generator outflow). I have already upsized the fins to max for the design, up from around 5 SF to 7 SF.
I think Ive hijacked the thread...so, I'll add that I would never be concerned about making use of quality used systems, but replace any wear items on the way in, not deal with after.
Converting a BT to hydraulic isn’t a small job as you need to run hoses all the way forward. Your hydraulic pumps will have to be strong enough for that as well. I know that when running on one engine, we loose about 50% thrust on our thruster. adding a PTO and hydraulic pump on a gen takes a lot power from the gen. For instance our 47kw stumbles breidfly when the PTO engages.
I have a route to get the hydraulics there, and I have a desire to shift the battery weight to the Lazz. Don't feel I need a stern thruster, but I sometimes wish my bow thruster was more robust...so it's a sum of pieces that generally fit in the puzzle...
indeed hydraulic thrusters are much better and can run longer but as mentioned need good pumps. Only downside is that have to fire up the mains if you need to adjust lines against a strong winds. stern thrusters aren’t needed on twin screw boats.
I disagree. On a 70 footer used mostly at displacement speed, gyros are as useful as a chocolate teapot. They might be a bit better at anchor, but properly sized modern fins stabs are almost as good also at zero speed, and simply in another league while under way. Regardless, the main problem I see vs. what the OP is asking is that, as for most boating equipment, if you spend a helluva lot you still risk to get a poor result. But if you spend a little, you are SURE to get that.