Click for Northern Lights Click for Llebroc Click for Westport Click for JetForums Click for DeAngelo

Pod drives for large yachts

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

  1. jsschieff

    jsschieff Member

    Joined:
    Apr 3, 2010
    Messages:
    44
    Location:
    Middletown RI/Stuart FL
    I read with interest that the new Jongert 47 meter Revolution yacht will use pod drives instead of traditional shaft/propeller. Pod drives have been used by large commercial vessels for some some -- I think there is a brand called Schottell that is used by tugboats. I believe several cruise ships have been built using pod drives.

    I wonder why pod drives have not been developed for super yachts or mega yachts prior to now. Pods have spread into the medium yacht market quite quickly and have shown to provide improvements in efficiency and handling over traditional shaft drives.

    No doubt there are knowledgeable members of this blog who know why the large yacht market has been slow to adopt pod drives.
  2. germanyachting

    germanyachting Senior Member

    Joined:
    Jul 26, 2010
    Messages:
    1,398
    Location:
    West Coast
    There are a couple yachts with it. Lurssen's Ice, Alstom's Kogo, Pichotti's Grace E, Wider's Genesi all have them. Eclipse and Al Mirqab both have one center pod. The argument that I heard before is that it takes up valuable space in the stern so having traditional shafts is easier and probably less expensive.
  3. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    9,658
    Location:
    Fort Lauderdale
    Not enough demand. PODS have been and currently are in use in tug boats and large cruise ships. They are efficient and highly maneuverable.

    NOW, this is what I know in regards to yachts. Pods have been slowly increasing in the HP game, problem was Cummins doesn't, and Volvo didn't have a large enough engine to put in front of a heavier duty pod. Volvo has been slowly stepping up with both aspects, Zues is at a stand still.

    I love the pods in a twin engine configuration. BUT, many larger yachts, let's say 58'-100' need 3 or 4 pods......I've seen 30-40% fuel efficiency gains with 2 pods versus conventional. With 3 pods instead of twin inboards the gain is only 11-13% and hardly worth the trouble. In boats 4 with pods, virtually no gains in fuel efficiency, and LOTS more headache maintaining 4 engines and 4 pods.

    The megayacht market is a very small pie when it comes to engine sales and boats built. Not enough for someone like Volvo to want to try their luck with, I think. NOW, if the ZUES project had CAT involved or MTU who already had big HP engines, I think the market would look different. Zues is a conglomeration of Cummins, Mercruiser, and ZF. Right now, they haven't come out with anything over 600hp and volvo has up to 900hp from what I know.....But it's a lot more involved to design, implement, and build a lot larger engine from scratch, than to build a larger pod.
  4. germanyachting

    germanyachting Senior Member

    Joined:
    Jul 26, 2010
    Messages:
    1,398
    Location:
    West Coast
    In the megayacht market, I believe there are a lot of commercial options out there for them. I listed several examples from 150' to 531' and I know of smaller yachts, such as Icon's 30m under construction, or Jetsetter by Dynamic (120' or so off the top of my head) that have pods. I don't really think the argument is there for these other engine manufacturers for yachts in the 30-70' range HP limitations to be reflected in the mega yacht sector. It is a good argument from about 70' to 100' while talking about more planning boat designs. I'm surprised that manufacturers don't use ZF pods more in this size range. I think I've seen current offerings of MANs up to 1,200 HP coupled with them but they may have a higher HP option as well.
  5. olderboater

    olderboater Senior Member

    Joined:
    Sep 2, 2013
    Messages:
    4,109
    Location:
    Fort Lauderdale
    It's odd though that there is for the most part a huge void between smaller boats and large commercial ships in terms of pods and you look at a boat like the Jongert and they're talking about using pods that haven't been developed yet. Either the customer isn't wanting them or the builders are finding they just don't meet the need of yachts. I wish we knew from the builders the answer to that.
  6. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    9,658
    Location:
    Fort Lauderdale
    Cat has used ZF pods with C18's as well. The problem is the warranty game. Which I was involved with, in 1 boat that had CATS and ZF pods. Boat developed a vibration. CAT came out checked the boat did a seatrial, pointed the finger at ZF. ZF came out, did a seatrial pointed the finger at CATs end. Luckily boat was owned by the manufacturer. Then I was running the boat back from the Miami show, and heard a bang and BIG vibration. Turns out the carbon fiber jackshaft started shredding inside the coupler where it was mounted to the motor. Problem exposed and builder changed the carbon fiber jackshaft.

    With CMD/Zues I've heard of some finger pointing going on as well. I think CMD really screwed up (and this is Brunswicks fault as they insist on keeping all vendors in house, for example searays need to use mercruiser or cummins engines until they can't. Like the piss poor performing 59' searay with 3- 600 hp engines/pods instead of 2-900 HP IPS). By not partnering up with CAT and making larger pods and moved up to a pod with a C18 1000 or 1150HP.

    With Volvo, it's all volvo. So if you have a weird issue such as above, it's clear who to call and who to handle it.

    I'm not knowledgable about the megayacht offerings and don't know what's available.
  7. K1W1

    K1W1 Senior Member

    Joined:
    Sep 30, 2005
    Messages:
    7,393
    Location:
    My Office
    In the larger end of the yacht market the pods in use are predominately Azipods. Some are with the motors in the pods and supply air to keep the water out, others have the motor inside the ship and use right angle gears to transfer the drive.

    The use of pods requires quite a beefing up of the stern area where the propellor thrust is transferred to the hull. This would normally be handled by a thrust block mounted in the shaft line.

    I have recently been told by a builder that props and shafts are a cheaper build for a 150m vessel, I am waiting to find out how much cheaper and what they claim the differences will be in life cycle costs and the all important vibration levels should either option be chosen.
  8. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    9,658
    Location:
    Fort Lauderdale
    KIWI- I've found on the yachts under 80' with pods that vibration is much much lower than shafts when underway and at cruise as well as reduced noise. Maneuvering (with the joystick) it is much higher on some boats as the computer is giving the engines more throttle than you'd normally use docking, a lot of wash under the hull, and props cavitating from wash. Not sure if this applies to your situation.
  9. K1W1

    K1W1 Senior Member

    Joined:
    Sep 30, 2005
    Messages:
    7,393
    Location:
    My Office
    That's pretty much my understanding of it. It remains to be seen if the reduction in build cost is offset by more vibration and the cost of mitigating this.
  10. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    9,658
    Location:
    Fort Lauderdale
    There's also the fuel savings. Now, what you're building is WAY out of my realm of knowledge. BUT, on the boats I deal with, If you can go with a twin pod installation, I see a solid 30-40% reduction in fuel burn verses the same boat with shafts, which I would think would translate over to what you're building, but not sure. Triple pods generally only up to a 13% reduction in fuel, 4 pods, no fuel savings over 2 props/shafts.

    I've run one brand of 40' express, both boats configured exactly the same and same fuel load etc.
    800hp MANs/shafts 31.5 knot cruise 64 GPH (80% load)
    600HP Zues pods 32.5 45 GPH (80% load).
  11. K1W1

    K1W1 Senior Member

    Joined:
    Sep 30, 2005
    Messages:
    7,393
    Location:
    My Office
    The project mentioned above is not being built as yet, its still in the early discussion phase to see if what the yard can offer is along the lines of what the Owner will like and accept.

    The cost of one of these is eye watering and even guys who can afford to own and operate one know what these big numbers are and are generally as frugal as the rest of us.
  12. Fishtigua

    Fishtigua Senior Member

    Joined:
    Jul 20, 2007
    Messages:
    2,288
    Location:
    Guernsey/Antigua
    I've worked with both IPS and Zeus drives. As a Cummins man, I'd stick with IPS any day of the week.
  13. muscled430

    muscled430 New Member

    Joined:
    Feb 13, 2016
    Messages:
    31
    Location:
    Italy
    Ok........what do you use your boat for? If you use your boat for real boating and not for just going few hours out of the port to swim, I will never buy a boat with IPS.
    Advantages are a little less consumption, almost zero vibrations, very low noise, but let's talk of disadvantages : maintenance is more expensive, they suck in everything they find in the sea (which all the troubles you can image), and they are like two big hooks under your boat......safe? not really.
    About docking, yes they have a joy stick, but if on your boat you have bow thruster you can do the same job without big problems. If you think you are very bad in manouvring, then a bow plus a stern thruster will solve the problem.
    Anyway if you have to choose between Zeus and Ips, choose IPS. Zeus gives only problems.
  14. Fletcher500

    Fletcher500 Member

    Joined:
    Feb 1, 2017
    Messages:
    71
    Location:
    San Diego
    Hello everyone, new member, first post.

    Agree. I have a joystick and rarely use it. I would not spend the money on it again, and if there is another boat in our future, it's back to shafts and a thruster.

  15. muscled430

    muscled430 New Member

    Joined:
    Feb 13, 2016
    Messages:
    31
    Location:
    Italy
    Hi Fletcher500, well the good options are shaft (not a V-drive, only extra problems for a bit of more space), surface (not Arneson, a lot of maintenance head aches, choose instead Topsystem ) or jet (in this case make sure it is an heavy duty one like Hamilton).
    All the other propulsions are good just for going for a quick swim.
  16. olderboater

    olderboater Senior Member

    Joined:
    Sep 2, 2013
    Messages:
    4,109
    Location:
    Fort Lauderdale
    Welcome aboard. Force yourself to use it some and really learn when it can benefit you. Yes, you can do anything without a joystick you can with one. We don't have pods but we do have joysticks. There are times they are a remarkably useful tool. Our engines and thrusters are tied into ours so it's being able to use one control vs. many in maneuvering. Also learn to use your dynamic positioning when waiting for bridges or locks or other things. These may all be tools you didn't need, but they can be useful in some circumstances. If you don't attempt to increase your use of it, you'll never know. I have no interest in owning IPS or Zeus but I've found joysticks useful.
  17. Fletcher500

    Fletcher500 Member

    Joined:
    Feb 1, 2017
    Messages:
    71
    Location:
    San Diego
    I am comfortable using the joystick, and have used it on occasion to walk sideways, or if the Admiral needs some extra time on windy day with a side tie. I grew up using the shifters, so that is where my comfort is.

    In general, they are a great marketing tool for people who have not had much experience with boats, and want a large boat now, but that is a different discussion.

    Regarding just good for a swim, I will disagree with that. We routinely run the boat on 50 - 250 mile trips (short trips in the world of cruising, but my wife and I still work, so hopefully longer trips are in our future when we retire in a few years :) ) and they work fine. My original post was more about the joystick. I just don't think they are worth it if the operator is already comfortable with shifters for maneuvering.

    But, lots of advances and choices out there. Excting stuff.
  18. muscled430

    muscled430 New Member

    Joined:
    Feb 13, 2016
    Messages:
    31
    Location:
    Italy
    If we are talking about joystick....well a nice marketing thing but basically useless if u have stern and bow thrusters, which by the way are much safer than a joystick with IPS system, since IPS has the fantastic quality to suck everything in, so it is kinda easy to end with a rope around your propeller. If instead it is a joystick connected to bow and stern thrusters, then ok you might be more happy to move only one level instead of 2, but I do not see the difference. About my comment that IPS are only good for a swim and not for cruising....well you can cruise without problems with IPS, but at your own risk : you have 2 or 3 or 4 (depending on how many engines u have) hooks under your boat, so everything you will find on your way (trunk, log......) will damage the system and, if the yard did not do his job properly, will open a huge hole under your boat. Obviously you should be unlucky, but I will never even think to go from Miami to Bahamas using a boat with IPS system, since I will not feel safe.
  19. olderboater

    olderboater Senior Member

    Joined:
    Sep 2, 2013
    Messages:
    4,109
    Location:
    Fort Lauderdale
    First, let me be upfront that I'm not a fan of Zeus or IPS although would choose IPS over Zeus. Our most recent boat was offered with either IPS or conventional shafts and we chose shafts. In doing so, we chose less efficient use of fuel. We did choose joysticks though.

    However, our reasons were different than stated above. We were intending to cruise in many areas (covered about 6000 nm total the first year of use of that boat) and were concerned about the service on Volvo and IPS vs. MAN and conventional. Also, our own staff lacks IPS experience although they have a lot of pod experience in commercial applications.

    To address the comments above. I wouldn't call IPS pods hooks and the risks versus conventional is only slightly greater. You hit things with any shafts and props and you may have damage. Conventional shafts are more likely, not less likely to lead to water ingress. However, conventional are also more likely to just have propeller damage with no other damage vs pods experiencing greater due to the angle. Regardless, to say IPS is not good for cruising is an opinion I can't agree with. Do they have disadvantages in some cruising areas? Perhaps. But they're used successfully and happily for many who cruise. We're taking degrees of difference between conventional shafts and pods, not the difference between night and day.

    For one to say they wouldn't think of going from Miami to the Bahamas with an IPS system, since they'd feel unsafe, is fine if they feel that way, but there's not really much logic to support that, it's just an emotional thought. What are you going to encounter along the way that you fear? Is the Gulf Stream going to rip the pod off? Not many tree limbs in the middle of the ocean.

    I wish Lars would speak up about Delta's experience with IPS as I know they've long been committed to that route.

    Pods of various types have long been used commercially and with great success.

    Now to joystick. The IPS system is simple and easy to us. There can be no disputing that. Add in the DPS functions and you have an excellent system. It is easier to dock using it than conventional controls on conventional drives. Now for those of us with experience, we're fine with conventional, but the IPS joystick in general makes the task easier.

    You can achieve the same on conventional drives. Couple a joystick with thrusters and engines. You're talking one lever vs. two, three or four. You're talking one lever vs. two systems. You're talking one lever vs. throttle, shift, bow thruster and stern thruster. It's definitely easier to use and it requires less thought to do as you wish. It's not just docking, but in locks, waiting for bridges, many things. It also facilitates DPS and the two are often done in conjunction with each other. Sit at the Macy's parade where you can't move but must keep the engine on and you'll be thrilled you have DPS. Waiting for bridges and locks you will be.

    There was a time people were opposed to combining two engines into a single control. Now that's the norm. At some point, I believe new builds without joysticks will be unusual. They'll become the norm just as having controls at multiple locations and/or having wireless controls are becoming.

    I can operate a boat fine without joysticks. However, I still like having them and will use them.

    Muscle, what boats with IPS have you run to give you such a negative opinion? What joystick systems on other boats? And what is there between Miami and the Bahamas you fear so with joysticks? I'm just asking to understand your experiences that have led you to such strong opinions.

    I've only run two boats with joysticks, one with Zeus and one with IPS. Both were a pleasure to operate. This is from someone who chose not to buy them. I've run tens of thousands of miles on boats with conventional drives and joysticks and found them to be a nice additional piece of equipment.
  20. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    9,658
    Location:
    Fort Lauderdale
    This is all complete and utter BS and totally untrue. Completely untrue. First and foremost, pods are nothing more than larger stern drives, just mounted underneath the hull. I have done well over 10,000 NAUTICAL MILES with pods and have run about 30 different yachts with pods (Zues, IPS, and ZF).

    If the pod breaks off due to hitting something hard or grounding, The Boat doesn't get any water inside of it. I have physically seen this on three different occassions. I watched a guy in a 45' searay go over the (dry) sand jetty at Hillsboro Inlet at 25 knots, left both pods on the beach, boat landed in the lagoon where a seatow operator happened to be, he hooked up to him and towed him to Merritt's, a couple of guys went and got the pods off the beach and the boat was fixed that same week and back in the water. I also was doing a delivery and overnight another captain in another yacht travelling with me hit a log or container or something at 8 knots, it sheered the two forward bolts on one pod and it was hanging there by two bolts. They then made it another 120 miles on one engine to St. Thomas. The mate dove under and took the pod off with an airbag while the boat was in the water, and they got the bolts flown in and put it back in 2 days later and were on their way. I also had an owner run his motoryacht aground with both pods and also no water intrusion.

    SECONDLY, they do not suck stuff in nor does anything you run over find their way in there. They are almost always mounted on the V and at an angle and usually above the boat bottom. They do stir up more water docking, but I have never, in all my travels sucked anything up into the pods. This is with lots of time in the Florida Keys with crab traps everywhere. The volvo's have line cutters also.

    Thirdly- the joystick with a bow and stern thruster is not the same, not even close to the maneuverability with pods. If the thrusters are electric and you're doing a lot of maneuvering, you have a minute tops and they're hot or out of juice. Hydraulic bow and stern thrusters are better with a joystick system, BUT if you're using them hard like walking the boat sideways after a few minutes they'll too usually heat the oil too much and overheat. ALSO, they don't have nearly the power to go dead sideways like the PODS do. The pods you can sit there and grind on that joystick all day long or maneuver the boat sideways at 7 knots for a mile with no fan fare. Also the DPS or skyhook function is awesome and the joystick/bow thruster system does not offer this. Yes, I have run several yachts with the joystick/shaft/bow/stern thruster system also....it's not as powerful, not as fast, and not as good.

    There are some situations like Olderboater has mentioned where the DPS is invaluable and worth it's weight in gold. Deep dropping, waiting hours on a bridge or lock in a place you can't anchor.....DPS will keep the boat facing the same direction and hovering within 40', it's amazing technology and it doesn't matter how much current or wind there is......

    Not to mention you are missing the other great features of the PODS, fuel economy and total lack of vibration and much less exhaust noise. I've run several yachts where pods and shafts are offered and ran both models. The pods in a twin engine installation offer 30-40% better fuel economy at cruise AND slow speeds, much quieter, more room in the engine room and faster (in some cases). For example, the 40' Cabo express with tower and 800HP Mans cruises at 31 knots at 64 GPH (80% load), the same exact boat with 600HP zues cruises at 32.5 knots at 45 GPH (80% load), that is a HUGE fuel savings.

    Now, if you need to go to a triple or quad POD installation, I'd rather have twin engine/shafts and a bow thruster. With 3 pods you only get 10-15% better fuel economy and maintaining 3 engines isn't worth it to me......4 no fuel savings.....so just the manueverability isn't worth it to me.

    Muscle, you ever try to dock a fast Sportfish with a bow thruster and palm beach controls....you need three hands..... the joysticks come in very handy in certain situations. This is coming from a Captain that has no issues docking large yachts with NO thrusters.

    Olderboater- from what I'm reading, my guess is Muscle hasn't run a single yacht with pods and is going off of complete dock talk from other people going on heresay.

Share This Page