Retrofitting Pod Drive to a Sailing Catamaran

[Catalysis]

I'm contemplating a new project. Purchasing a used 50 foot catamaran from charter that has existing saildrives but needs new engines and retrofitting new 56-75 hp yanmars with ZF or similar Pod drives.
Anyone done this or researched options ?
Appreciate comments
Paul

[Palarran]

Why?

I'm sorry to say but this has to be one of the oddest pursuits for a catamaran refit I can imagine. I would be harsher about the idea but would run afoul of the forums standards.

[downunder]

Originally Posted by Palarran

Why?

I'm sorry to say but this has to be one of the oddest pursuits for a catamaran refit I can imagine. I would be harsher about the idea but would run afoul of the forums standards.

Have not looked at the specs however pod drives and sail drives are quite similar to install but pod drives can cater for higher horsepower.

Most smaller pod drives seem to be installed on planning hulls ?

cheers

[Palarran]

My understanding is pod drives rotate in order to provide more side movement and joystick control. If I'm incorrect then I apologize for my thoughts on the idea.

A 50' catamaran would have very little benefit versus cost with these drives. I remember someone asking about installing bow thrusters on a cat also and couldn't make sense of that. With two motors mounted so far apart, your control is very, very good. I'd focus much more on making the boat faster under sail.

[downunder]

I have not been able to find any designed for low horsepower that would be cost effective.

Are most likely much more costly than sail drives.

[joda cancruise]

Originally Posted by Catalysis

I'm contemplating a new project. .... retrofitting new 56-75 hp yanmars with ZF or similar Pod drives.

Paul, is not the ZF your are referring to a transmission? A “pod” drive is more a rotating pod that big ships use for propulsion and steering, usually electric drives. All ZF transmissions that I have seen are mounted inside the boat with a shaft drive attached.

As a side note if you end up going this route I will gladly take your Antaries off your hands for technical advice on your project. lol
Dave

[Morrissey]

Pod drives such as Volvo IPS or Cummins Mercruiser Zeus do rotate for maneuvering, but biggest advantage is having counter-rotating props on each pod, alleviating 'prop-walk'. But they typically spin quite fast and have relatively small diameter. Great for planing boats. On a sailboat the appendage drag will be high when motors are off. Not sure if there are any pods with folding/feathering single prop.

I can believe the need to repower an ex:charter cat with larger engines, but up-sized saildrives, with as large a diameter folding prop as possible, would be best option IMO.

[GordMay]

The ZF Pod Drive
➥ http://www.zf.com/media/media/docume...00_2010_07.pdf
➥ http://www.yanmar.es/theme/yanmares/...20brochure.pdf

[joda cancruise]

Gordon as always you are the expert, I sand corrected. Paul the offer on your Antaries still stands. Dave

[downunder]

Designed for 200KW upwards and planning hulls.

Certainly not suitable for a sailing cat.

[Catalysis]

The Youtube Beneteau "Dock and Go" video shows a Beneteau spinning in its own length.

They used a Yanmar 75 HP coupled to 180 degree swivelable Pod drive by ZF (SD-50 saildrive replacement) and a bowthruster all joystick controlled.

I'm trying to ascertain if a pair of similarly configured engines could achieve the same result without the bowthrusters due to a 50ft cats 25ft beam.

There should be no reason why a maxprop couldn't be fitted to the ZF drive. The saildrive configuration wouldn't look much different from an SD-50, certainly not the counter-rotation twin screw behemoth in the Volvo pictures.

For me I like the idea of single handed docking and picking up a mooring buoy regardless of wind and tide conditions - particularly as I get older.

[Catalysis]

Here's a picture of the modified SD-50 Pod.
Underwater profile very similar to SD-50 drive unit - biggest difference is it can rotate +/- 90 degrees.
The Beneteau Dock&Go system uses a 75 hp Yanmar diesel connected to a modified SD-50 sail drive unit. The modification allows the sail drive to turn from side to side

[Event_Horizon]

Originally Posted by Catalysis

The Youtube Beneteau "Dock and Go" video shows a Beneteau spinning in its own length.

They used a Yanmar 75 HP coupled to 180 degree swivelable Pod drive by ZF (SD-50 saildrive replacement) and a bowthruster all joystick controlled.

I'm trying to ascertain if a pair of similarly configured engines could achieve the same result without the bowthrusters due to a 50ft cats 25ft beam.

There should be no reason why a maxprop couldn't be fitted to the ZF drive. The saildrive configuration wouldn't look much different from an SD-50, certainly not the counter-rotation twin screw behemoth in the Volvo pictures.

For me I like the idea of single handed docking and picking up a mooring buoy regardless of wind and tide conditions - particularly as I get older.

You can make a catamaran rotate on an axis or even crabwalk sideways without any modifications as long as both engines work.

[mark_morwood]

Originally Posted by Event_Horizon

You can make a catamaran rotate on an axis or even crabwalk sideways without any modifications as long as both engines work.

Or in my case if both saildrive clutches are working. :-(

Seriously, before engaging in this expensive option, I'd suggest the OP get some time on a catamaran with twin engines and someone who has experience to see if you need this. Having transitioned from single engined mono-hulls, I've been amazed at the control and maneuverability I now have with a twin engine cat with saildrives.

Mark.

[Catalysis]

I appreciate all the advice on getting tuition on handling a cat. In my case I have many years (30+) sailing experience including the last 2 years owning a large cat.

i.e. I can spin (or is it twirl) my cat at will.

However what I'm considering is a technology experiment that will allow precision control of a large cat (hold a fixed spot, move with precision to another spot - the dock etc ) so that singled handed people (who may be aging but don't want to quit)have the option of retrofitting fixed plane saildrives with GPS controlled rotating drives.

I fully realize that there are trade offs (cost, complexity etc.) but believe that the positives are also worth evaluating. The technology is rapidly changing and NMEA 2000 based systems offer options that just weren't available a few years ago.

One of the great features of this forum is the breadth of diverse opinions and I appreciate suggestions that may help move the project forward.

Paul