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Pod drives for large yachts

Discussion in 'General Yachting Discussion' started by jsschieff, Jan 19, 2017.

  1. Fletcher500

    Fletcher500 Member

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    Captain J/Older, it is good to get feedback from people who have run these systems over a lot of miles. It is also interesting to hear different view points, but facts do matter.

    When I was on merchant ships years ago we were burning oil, to heat water, to make steam, to turn a turbine. Technology is a good thing.
  2. Capt J

    Capt J Senior Member

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    The fact that Cruise ships and many commercial ships have been launched with PODS over the past 10 years +/- tells me that they are reliable and there are benefits to them over going with shafts says something. I agree that technology is a good thing. I'm the wait and see type for a little while, but do embrace it.
  3. jsschieff

    jsschieff Member

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    Pod drives seem to be breaking into the large yacht market. A friend from Maine told me today that Front St. Yachtyard in Belfast recently refitted a large (100'+) motor yacht from shafts to pod drives. Must have been a heck of an engineering and installation challenge.
  4. olderboater

    olderboater Senior Member

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    Well, there are many pods and some have long been used in large boats. As to IPS there are incidents of them fitted into 80-100' MY's with three or four units installed.
  5. CaptPKilbride

    CaptPKilbride Senior Member

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    I am a bit surprised about your comment regarding maintenance headaches with Arneson Drives ... can you expand on that? What headaches have you experienced?
  6. BoulderGT3

    BoulderGT3 Member

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    I owned a boat with IPS500's. I didn't see the real world fuel savings being discussed above. In rougher water they didn't have the torque of straight shafts and were much more in and out of the boost. Fuel savings were maybe 10-20% in what I call actual conditions. Lower vibration, low bow rise and quiet. I would buy another pair for the way I use a boat but I think they are great for some people.
  7. Capt J

    Capt J Senior Member

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    Imaginary ones!
  8. sgawiser

    sgawiser New Member

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    We did 500 hours on a Sabre with IPS and not only got the expected increase in fuel mileage but also had no issues on multiple trips to the Bahamas and many other cruises. In fact, we have a new Sabre on order with IPS and expect similar results.
    The maintenance costs are a little higher but if you use the boat, you have can offset some of that cost with the fuel savings.

    We also have two friends who managed to drive their boats aground at speeds exceeding 20 knots. Both lost a pod but had NO water intrusion at all. Other people we know who did that same with shafts had a more serious issue with water into the boat.

    The quiet operation and underwater exhaust make a boat with these drives much more pleasant to use.
  9. K1W1

    K1W1 Senior Member

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    I worked for a guy who had a set on a Magnum 56. They gave a lot of problems with seals and the circlip that retained the thrust bearing getting popped out
  10. Capt J

    Capt J Senior Member

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    I was speaking more of the credibility of the OP. I've been managing a 59' Baia with Arnesons for over a year. So far no issues with them. Having water in the boots is normal. Sometimes you can have seal issues on the steering seals or trim rams if they're not used or worked and a diver isn't cleaning them on a regular basis and you get growth on the shaft of the rams. I always leave the drives trimmed all of the way up, so no issues with growth on the trim rams to worry about. All in all they're a pretty simple system, but not as lenient for sitting around without being moved around like shafts are. I trim and steer the ones on the boat I manage every 2 weeks and have a diver on it monthly. And, well you need 3 hands to trim them and get on plane.....LOLOL......but they're very efficient, I've calculated 1% prop slip.
  11. Fletcher500

    Fletcher500 Member

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    A little thread drift regarding the Arneson drives...There is a sunseeker at our marina that has them. I often stop and check out the props and marvel at their design. They remind me of a sub prop. I have heard on a different forum that at lower speeds a boat with these can be difficult to handle? They guy who runs this particular boat seems to have no issues coming down a narrow fairway.
  12. Capt J

    Capt J Senior Member

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    It's backing up that's the issue and docking. The newer Arneson boats have gotten a little better. But in reverse the thrust mostly washes against the transom and the boat reverses very slowly and washes around. Then since an Arneson boat is propped based on only using the bottom 1/2 of the prop, it's way overpropped when at hull speeds, so docking when you bump one in forward they jump forward like a NHRA dragster and about 20' pretty quick.
  13. Fletcher500

    Fletcher500 Member

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    Interesting. The guy who drives that Sunseeker drives in reverse several hundred feet, in a gap of about 75 ft. He then goes stern in, to a side tie, with a sea wall about 15 ft. away, and on low tide some very skinny water between the boat and that wall. I always thought he did a nice job parking, and now I have even more appreciation for it.
  14. Glyn willmoth

    Glyn willmoth New Member

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    As far as I can see there are no pods available for the +/- 2000hp motor market correct me if I'm wrong , hence large sport fishers and the like have to have multiple pods i.e. 3 or 4 which negates the fuel savings and in fact just adds to the coats of running with maintenance etc.
    Some of the yachts are running 45+ knots on shafts , yet it seems all pod IPS Zeus and even ZF claim only 37 knots top speed irrespective of multiple pods is this prop design or manufacturing limiters?
    Perhaps this is why custom fishing boats builders are very slow to take the idea up.
  15. NYboater

    NYboater New Member

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    The Wajer Osprey 38 is reported to do 45 knots at WOT with twin IPS 600
  16. Glyn willmoth

    Glyn willmoth New Member

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    Yup my point exactly 38 foot the moment you get over 60 feet the problem starts
  17. K1W1

    K1W1 Senior Member

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    The problem being the pleasure boat market in that size range just isn't a big enough market to warrant large expenditure and risk in the design and development of a small pod to deal with that part of the market.

    There are plenty of options for pods when you get bigger
  18. NYboater

    NYboater New Member

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    German company, Reintjes make a fixed pod with fore and aft props that can handle up to 2,600 HP.
  19. Fishtigua

    Fishtigua Senior Member

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  20. captholli

    captholli Senior Member

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    Rolls Royce owns the designs or the licensing rights now for Ulstein Marines Fwd. facing drives or tractor drives in fixed and CP, azimuthing and rudder flap designs. To my knowledge Ulstien has been placing their fwd. facing drives in yacht applications since the late 1980's. Broward Marine had three vessels built with the Ulstien tractor drives installed in twin DD 1692 applications one with fixed pitch and one with CP and the other with a triple engine configuration with a Riva Calzoni fixed water jet center line.. Very nice systems even back then and I can only imagine the technological advances made in the last 28 years or so with these drives.
    Last edited: Feb 19, 2017

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