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2001 Horizon 76 - Sea Trial

Discussion in 'Horizon Yacht' started by TahoeJohn, Oct 8, 2020.

  1. TahoeJohn

    TahoeJohn Member

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    Hi,

    My wife and I are in contract to purchase a 2001 Horizon 76, twin Cat 3412Es, skylounge, stabilizers, etc. We went out for the sea trial today and generally things went well. We did 21-22 kts at WOT at about 2300 RPM (both engines) in 2' seas off Ft. Lauderdale, not terrible for a 125,000 lb boat.

    As soon as the captain pushed the first WOT test, at around 19-20 knots, the boat heeled to port. The captain put full down on the port trim tab, which leveled the boat out. The Cat guy, the surveyor, and the selling agent all assured me that this was fairly typical for a boat with counter-rotating props, and even more typical for Horizons.

    I don't have a reason to distrust them, but I would like to hear your thoughts on this if you don't mind.

    Thanks!
  2. BJG

    BJG New Member

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    I just sold a 2017 E75... we had no issues at speed of the boat leaning over. In fact, our experience was that the trim tabs did very little for the boat... lol
  3. Capt J

    Capt J Senior Member

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    It has nothing to do with counter rotating props. Could have been the stabilizers reacting to the sea, the windage, etc. A skylounge adds a lot of weight up high and can make a vessel lean more. if the trim tabs leveled the boat out and it handled ok in different directions, etc., I wouldn't be worried about it. If you hired the surveyor directly, then call him/her and ask them, now that they're not on the vessel in front of brokers etc. and ask them their thoughts.
  4. TahoeJohn

    TahoeJohn Member

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    Okay, thank you. My intuition says that the whole purpose of counter-rotating props is to cancel out such unilateral effects.

    I did talk with the surveyor just now and he shares your assertion that it's not a huge deal, some boats do this, some don't, etc.

    Glad to hear this from Capt J directly!
  5. Pascal

    Pascal Senior Member

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    21/22kts sounds pretty slow at WOT for a 76 footer with 3412Es... Were the trim tabs down to get best speed? Could some pitch have been taken out to get tires engines to turn RPM?

    i used to run a Johnson 70 Skylounge with the same engines which hit 30kts on sea trial with 5400 hours on the engines. A 76 is a little heavier but still that s sound slow.

    Is the boat stabilized? An unstabilized skylounge isn’t going to be fun.

    How quick was the heeling to Port? I ve never seen that unless maybe the trim tab was full down on the other side and / or you had quartering seas. As J said, counter rotating props should even out the torque
  6. Capt Ralph

    Capt Ralph Senior Member

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    I think I may have read something different; One throttle with out the other engine offering any or less torque to the hull, then the second engine up and leveled out then?
    Trim tabs on a 76' boat with stabilizers??? Like a car jack for an ole Citroen.

    Both engines offering the same torque on the hull should not have listed the ship, One with a lot of power on could, IMO.

    How loaded was the boat? fuel , people, mother in-law & lots (lots) of live-a-board clothes, groceries, spares, stuff & junk?
    Stabilizers showing centered? May have to double check the stabilizers for zero angle, un-parrelle fins will rob some speed and cause some strange manners.

    I also would liked to see a lil more speed. Maybe full of junk. Like our boat, live-a-board for 17 years, some top end speed has been lost.
    Last edited: Oct 8, 2020
  7. TahoeJohn

    TahoeJohn Member

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    Hi Ralph, if you're referring to something I wrote... no, both throttles were moved together from idle to WOT for this test, per the Cat tech's instructions. Then the port trim tab was used to level out.
  8. Capt Ralph

    Capt Ralph Senior Member

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    I read it to fast. Sorry 'bout that.
    I still think there is an error somewhere. Maybe a damaged wheel or un-parrelle fins.

    Heck, it could be the stb tab was already down, the port tab is leaking and had to get pushed down again, seas and/or waves on the hull as you sped up or the fat guy in the back changed sides.
    Maybe to much tab kept the boat level and bow in to much slowing you down.

    Time for another ride, schedule a few of us next time..
    Last edited: Oct 8, 2020
  9. TahoeJohn

    TahoeJohn Member

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    Yes, I tend to agree. Your thought of un-parallel fins gets me thinking, because Naiad has been out to the boat a lot lately, fighting issues. Maybe next time I'll have them pin the stabilizers and see what happens...
  10. Capt Ralph

    Capt Ralph Senior Member

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    Just pinning the servos may not mean the fins are straight.
    Usually, the fins are on a long tapered shaft like a propeller, just no shaft key. It is not easy to do, but a grounding or collision may move the fin on the shaft un-detected.
    I'm glad you commented that Naiad has been on board. Gives me a nudge there may be something still amiss.
    Since my last post here, I'm still wondering about trim tabs on a boat with stabilizers.
    May be time for another surveyor and Cat tech.
    Oh wait,, Pantropic?
    Let me type that again; May be time for another surveyor and Cat tech.

    Pin the fins and have a diver measure that they are parallel to the chine or keel or have her picked up with locked fins.
  11. TahoeJohn

    TahoeJohn Member

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    Ah, that's really good to know that there isn't generally a key on those shafts, so somehow they need to be either adjusted or calibrated correctly. Very helpful, thank you!
  12. Capt J

    Capt J Senior Member

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    Look at the cat report, see what the loads were at cruise. If there is an issue with one stabilizer fin being out of alignment, you'll see a lot higher engine load on one engine over the other. Within 6% of each other at say 2000 rpms is normal. I think it's the nature of a Hargrave and the sky lounge and just the way they are.

    I once ran a new boat 90', that I've run many times, and we had a 25 knot wind off of one side and at 10 knots, 1000 rpms the one stabilizer was maxed out on one side to provide stability that the one engine was at like 68% load and the other engine 36%, and boat crabbing 20 degrees but going straight (autopilot). We were in ICW so no wave action.
  13. YachtForums

    YachtForums Administrator

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    You mean Horizon?
  14. Pascal

    Pascal Senior Member

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    I ve run two skylounges for the last 12/13 years. One a johnson 70 and now a Lazzara 84. I ve had run Either many many times with 30kts on the beam at hull speed I’m protected waters and never had different loads on the engines or any list/heel. Never. And the johnson was not stabilized.

    something is wrong with that boat.
  15. Capt J

    Capt J Senior Member

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    Yeah horizon.
  16. Capt Ralph

    Capt Ralph Senior Member

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    If the fins are a-mis. Calibration requires to find the servo center, then adjust the fin / shaft to that. Servo center requires finding the dead bottom of travel of a hump / valley in a cast cam part of the big/whole servo assembly. A rheostat is roughly installed on top of the shaft after all of this. On the op panel, it just shows a rough position of what it thinks is the shaft center (subject to a lot of BS inputs).

    The locking pins should be close from the original install but may not be a real center line of the fins, just close enough to operate in the event of a pump or other failure. In my past I have found the locking pins to be dead on, on others several degrees off line.
    There are hull dynamics where the fins maybe toed in/out just a few (very few) degrees. These would be in the Naiad (factory/Naiad) only black book.
    If I'm close to these errors, you are past these micro specs.

    Since I do not see many (any) objections to my ideas, I may not be far off on these plots.
    PM me for a phone number if needed.
  17. alvareza

    alvareza Member

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    +1

    If something is not right on the sea trial, you need to understand exactly why. Don’t believe it when folks on the boat ‘It will be fine’. Most of them are selling you the boat. I found this out the hard way. Ideally problem can be fixed and you seatrial again to prove it.
  18. Oscarvan

    Oscarvan Senior Member

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    Heeling when you put the coals to it seems off to me.... but what do I know.
  19. TahoeJohn

    TahoeJohn Member

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    Thank you all. I've asked for a complete and thorough history of all the work done to-date on the stabilizers, particularly the flurry of activity from this year. For example, in February the port block had to be replaced, so this system has had some major disassembly. New actuator on one side (still trying to pin down which side), etc.

    I'll also take a close look at the engine load information from Cat once that's done. They promised the report by Tuesday.

    Back with more info soon, and thanks again for helping me think through what's next on this boat!
  20. Capt J

    Capt J Senior Member

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    Do you have any pictures of the bottom and stabs that you can post?