Z Drives

Hi All
Please excuse this my naivety, I have read a number of displacement yacht builders talking about a Z drive.
However none of them go into detail about what a Z drive is? Or how it works? Or its potential advantages vs dis-advantages.
Could someone please enlighten me.
I have looked around ....
http://www.ptc.com/award/1999/design_html/512.htm

But the above link makes a z drive look like a nozzle to me.

Thanks

Search for Azipod on the net you should be able to find something on this topic. They are one of the most popular z-drives out there. Lots of benefits to z drives versus conventional shaft-prop-rudder. Very popular on cruise ships due to the maneuvering capabilities and the benefits of the diesel electric setup (i.e. can place main engine anywhere in the boat and just run power chords to the electric propulsion motor in the unit. I hope this enlightens you alittle.

Cheers

her you may find answers

this is a very interesting and informative site
www.steerprop.com

Z Drives, pleasure boats

You might have a look at this referenced website for a recent development in Z drives for use on pleasure craft. The interior details are not shown, but it consist of a 'Morris chain' steel belt component.

I believe Morris chain drives were originally developed in the fire fighting pump industry, and subsequently used in the engine/transmission connection in the front wheel drive Tornado car.

I've been very interested in the development of such a drive where kevlar belts would be substituted for the metal chain, and the drive would be configured in a pulling arrangement rather than pushing.....could be steerable as well, and or retractable.


http://www.pyiinc.com/index.php?section=news&action=5-2002/5-2002-driveleg&sn=1