ZF Marine debuts new propulsion concept for inboards

MattPMattP Posts: 5,883 Moderator
ZF Marine today introduced the “Project Disruption” concept at the Fort Lauderdale International Boat Show. The new propulsion package is the first contra-rotating system for inboards with traditional shaft-drive systems.

The concept lets inboard-boat builders take advantage of contra-rotating propellers; the most obvious advantage is improved efficiency. The concept takes a standard ZF Marine transmission and utilizes a strut-housed underwater gearbox to transmit power to the twin propellers. Initially, the concept was designed for water-sports towboats and ZF said it can be scaled to larger boats.

“For many years, there has been little innovation in inboard shaftline technology,” Keith Stanley, pleasure craft product line manager for ZF Marine, said in a statement. “ZF saw the opportunity to bring all the benefits of contra-rotating propellers to this most traditional of propulsion systems. We started with tow sports because it presented a unique opportunity to investigate the concept at full scale while subjecting it to a wide variation of loading conditions.”

In addition to increasing efficiency and acceleration, ZF said the concept will give boatbuilders the chance to consider a wider range of transmission ratios than what is possible with single-prop applications. It should give naval architects the ability to optimize the propeller-to-gear ratio.

Lastly, the contra-rotating propellers will address one of the biggest shortcomings of single-prop inboards — poor performance when backing up. They will eliminate the propeller torque, which basically only lets a boat back up in one direction.

ZF Marine debuts new propulsion concept for inboards
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Comments

  • RazorRoss3RazorRoss3 Posts: 1,193 Mega Baller
    But what effect does it have on my spray around the ball?
    thagerBill22
  • liquid dliquid d Posts: 803 Crazy Baller
    What? so now I won't be able to make fun of MC drivers when they get in my CC? What fun is that?
    jerrym
  • oldjeepoldjeep Posts: 2,596 Mega Baller
    edited November 17
    So it is like a Bravo duoprop I/O. Neat concept, hate to think what the props will cost. Looking at the props, sizewise they actually look like bravo props and the bottom of an I/O outdrive

    Chuck P
    Not a mechanic but I play one at home
  • MISkierMISkier Posts: 1,877 Mega Baller
    I wonder if the additional underwater gear (strut mounted gearbox, etc.) and/or any change in churn of the water by the combined props will negatively affect wake characteristics.
    The worst slalom equipment I own is between my ears.
  • BeekerBeeker Posts: 21 Baller
    @thager I could not agree with you more..$$$$
  • Jody_SealJody_Seal Posts: 2,158 Mega Baller
    @thager,
    Could not agree more. Overkill for a simple application. getting closer to the $100K ski boat as it is. I can see something like this on a lake tanker, however pod drive technology is fast becoming reality in smaller pleasure boats. Also this duo drive shaft unit is really nothing new. The Arnson surface drive is very similar however it is mounted on the transom rather then through the bottom of the boat.

    Viva La Revolution
    Hobby Boats can be expensive when the hobbyist is limited on their own skill and expertise.


    eleeskiA_B
  • WishWish Posts: 6,768 Mega Baller
    Boats feel diff already with diff manufactures to prop options to engine size options when it comes to ZO. So now more veriable options would be available to manufacturers?
    >>> 11.25..a different kettle of fish. <<<
  • oldjeepoldjeep Posts: 2,596 Mega Baller
    edited November 17
    I think the application is surf boats, not ski boats. Counter rotating props would take care of the issue where the surf waves are not as good on one side. The pictures are of v-drives, not DD's
    Chuck P
    Not a mechanic but I play one at home
  • DWDW Posts: 1,554 Crazy Baller
    I recall the Ski Pro Twister was fitted with the Volvo Duo Prop, had a top speed of 70 mph. IIRC not a stellar slalom wake. Agree not needed or probably wanted for a 3 event boat but time will tell.
  • JordanJordan Posts: 851 ★★★Triple Panda Award Recipient ★★★
    Hmmm....looks like an unneccessary complication. I also wonder if it will be a disadvantage to lose the directional bias of the single prop. I use that to my advantage when docking. While this set up will undoubtaedly go straight when backing up, it not turn any better when there isn't and current from the props washing over the rudder.
    Than_BoganGregHind
  • Keith MenardKeith Menard Posts: 195 Baller
    My daytime job is motorcoaches. ZF came in with catepellar a bunch of years ago and was going to REVOLUTIONIZE the motorcoach industry. You literally can't give those buses away now.
    Intheday
  • BeekerBeeker Posts: 21 Baller
    @Jody_Seal IMO no prop torque while driving a course would be kinda like tracking a hwy in a car with some loose steering.
  • bigskieridahobigskieridaho Posts: 581 Crazy Baller
    Dumb. Keep that stuff on I/O boats. Not even needed on V drives either. If it isn’t broke don’t fix it right?
    thagerpaul
  • Dacon62Dacon62 Posts: 433 Solid Baller
    edited November 17
    Wow...nobody has even tried or driven a direct drive with this tech and all this poopooing.
    It may be awesome or it may be a flop but let’s give it a chance. Hey it’s something new (potentially) for us direct drive guys. When’s the last time that happened!?
    BG1tdusinjcampThan_Bogan
  • JordanJordan Posts: 851 ★★★Triple Panda Award Recipient ★★★
    Simple is better.....this isn't simple.
    Keith Menard
  • UWSkierUWSkier Posts: 573 Crazy Baller
    My first thought was what @jordan said. Duoprop setups work well when the thrust direction is controlled by the helm. Unless there's a sprag clutch on the forward prop or something, the reverse "pull" that is ingrained in my being will be gone.
  • eleeskieleeski Posts: 3,060 MM Trick Skier / Eccentric Person


    Working on this?!

    Eric
  • oldjeepoldjeep Posts: 2,596 Mega Baller
    edited November 18
    @eleeski - mastercraft already made a twin engine wakeboat. X-80

    Chuck P
    Not a mechanic but I play one at home
    eleeski
  • A_BA_B Posts: 3,779 Mega Baller
    I would be more interested in an electric motor. Plug and Play!
  • eleeskieleeski Posts: 3,060 MM Trick Skier / Eccentric Person
    @A_B Two electric motors in a hybrid? With the right controllers the boat path and time could always be perfect. The human driver could watch Harry Potter videos (bad reference to a Tesla problem).

    @oldjeep Just one engine needed.

    ALPJrJody_Seal
  • DWDW Posts: 1,554 Crazy Baller
    edited November 21
    IIRC the electric CC had twin electric drives (actually one case with 2 rotors) with belts to 1 prop shaft.
  • oldjeepoldjeep Posts: 2,596 Mega Baller
    @eleeski that looks like a reliability nightmare, not to mention all the parasitic loss.
    Chuck P
    Not a mechanic but I play one at home
    Jody_Seal
  • lpskierlpskier Posts: 1,855 Mega Baller
    Don’t get a rope in the prop(s).
    John Wilkins- Si non pro sanguine quem ludus ne. #iskiconnelly
    Jody_Seal
  • eleeskieleeski Posts: 3,060 MM Trick Skier / Eccentric Person
    @oldjeep Compared to a counter rotating prop?

    I wonder if a single electric motor driving the prop where the energy comes from a motor/generator might be more efficient. It adds an interesting possibility to reposition the generator for wake adjustments. Run the engine back for tricks and wakeboarding and forward for slalom. Another project?

    Eric
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