Diesel Electric Propulsion

Voith inline thrusters

Brian, I have to agree. As prommising as those rim driven thrusters may be, as far as noise, efficiency and simplicity are concerned. But for 24/7 main propulsion, there are not very many out there.

I would concider them as a transverse bow thruster or as an swing out steerable stern thruster in a DE boat but not for main propulsion in a yacht or even in a commercial ship. I have seen plans for an retractable rim driven thruster as main propulsion on a racing sailboat but that is actually standby propulsion also.

It is still high voltage electricity far to close to water, only separated by one combined seal / bearing. With any kind of foreign object damage on the propulsor, the sealing capacity of that bearing will be affected and your electric motor might have internal raw water cooling .

As long as you do not need a really big electrical pod drive (above 5000 KW), I would always keep the electric motor out of the water (like the Schottel SCD or the SRP).

I was just reading back thru this subject thread, and marveled at the really serious contributions by some very knowledgeable participants. I only viewed the last half, so I still need to go back and review the first portion. What a great source of ideas/possibilities.

I'm reading back thru this subject thread and wanted to make a note of this posting.
Is Fischer Panda still one of the few players in this 'small genset' field? I want to consider something for an aux propulsion unit on a 40-45 sailing vessel.

And here it is 2016, and that prediction has certainly not come true to the extent Nigel Calder had hoped,....likely due to the financial depression following 2008.

I for one was very much looking forward to this future tech,

...some selective portions of your posting Karo...

There was a time when a company called Glacier Bay was working on an system wide approach they called OSSA Powerlite. If I remember correctly one alternative feature of one of their systems was that the engine/generator unit would be able to directly run the electric prop motor without need of a big bank of batteries (or very little battery power) ??

I am contacting them in the next few days to ask about their systems that might support an electric drive pod WITHOUT big battery banks.

Just ran across 2 of my own postings on this subject:

I became a real believer in this company's approach as it appeared to be the most 'comprehensive' ,.....Glacier Bay and the OSSA PowerLite System.
I wrote in several postings:

I needed to re post this posting I made, as I am again looking for a small DE system that might be configured thusly. Sorry for the duplication, but my memory is not what it use to be and I was trying to consolidate some of these posting I had made in the past.

WOW !! Karo I had forgotten all about this really excellent reply of yours. I need to make a print-out and reread it several times. Thanks SO MUCH


...and then you followed that up with 2 more related postings #133 and #134

...excerpts

[/QUOTE]
I wonder exactly how that patent of Volvo reads? I sometimes wonder if these patent examiners really search thru all of the 'prior art' before declaring 'no such prior art??

I recall drawing up a dual prop, pulling configuation back in 1992-93 era. The drawing is here:
Pulling Prop, Belt Drive (for my sportfishing/sailing cat)
http://www.yachtforums.com/threads/new-drive-system-from-volvo-penta.2232/#post-7567
But it was never published till much later, as I did not become computer literate until 2000. I think I submitted it to several magazines at the time, but they blew me off (fishing under sail?,...and with such an unusual sailing rig??)

I drew up my version of a Gamefishing catamaran after Lock Crowther created this one for a guy out in Bora Bora.

I figured my 'no mainsail', all-furling sailing rig would work out much better in a sailing/fishing mode. And I wanted to keep the props as far forward for less interference with fishing lines. So the dual prop arrangement would accomplish this, plus mean less draft for shallow water exploration.

I am going to do that here in the next several days, and I'll probably post a copy of that letter here.

Interesting, thanks

Couldn't resist posting this....

Are you going forward with this project of yours?
Are you still participating in this subject thread??

Email letter I just sent to FisherPanda, Oceanvolt, Vetus

Electric Motor Propulsion for 40 foot sailing catamaran

Dear Sirs,
I am working on a design for a 35-40 foot catamaran that I term a picnic/weekender catamaran. The concept will be somewhat similar to this one I found in Thailand a few years ago. I posted it on several boating forums a few years ago.
http://www.yachtforums.com/threads/weekender-picnic-powercat.13966/#post-173670





This particular catamaran was a powercat. I will be adding a sailing rig to it. I will also adding a trolling/fishing chair area to rear deck area,... so that pictured Zodiac dinghy will be relocated, and the two outboard engines need to be eliminated.

I need to repower this cat design, both for close quarters docking situations, and for some motor/sailing situations.
I have had a very long time interest in the rim-drive propulsion concept.
http://www.yachtforums.com/threads/rim-driven-propellers.3961/

What I have in mind at this moment is how I might adapt this Vetus Rim Drive unit to be my single primary propulsion propeller. I would like to mount it in the aft portion of a of the wingdeck of the vessel, and make it steerable upon demand, and also retractable when sailing. Naturally it requires an electrical supply, which as I understand it under present technology can come from a combination of battery power and a relatively small DE power plant. This power plant would be located in its own insulated (heat and sound) box up on the flat deck of the catamaran.

So here are a list of questions I have at the moment:
1) Can such a rim-drive propulsor be run continuous without overheating? It is my understanding that the Vetus unit can do that now.
2) Whether it is the Vetus rim-drive, or another electric drive motor, is it possible to operate such a 'DE system' with very little battery supplements?
3) How few batteries are required (in the interest to keep added weight down) ?
4) Is it possible to 'direct drive' this 'electric prop' with the DE power plant, or are batteries required.
5) I realize Vetus has its own DE power plant, but it appears that FisherPanda has an even greater selection of small DE power plants. Can these systems be mixed?
7) Should the Vetus rimdrive prove not powerful enough, what are the other alternatives that anyone would suggest??


As an example of why I might be considering this approach, I will offer this personal experience of mine. I was the original importer to the USA of French catamaran line,... the original model was a 37 foot boat called the Louisiane 37. I placed a 9,9 hp Yamaha 4 stroke Hi-Thrust outboard engine on it. It was a limited production outboard they made with an extra gear reduction in the output prop shaft so it could turn a bigger propeller. It worked pretty good as we got 7 knots out of the vessel in calm conditions. The engine was mounted in the center on a rear beam of the vessel, and soft lines were lead from the engine to the rudder arms so when docking the engine would steer along with the rudders. Maneuverability was VERY good. It made me a believer in 'steerable engine', verses twins,...an alternative to consider.

All Electric 'Tesla' Speed Boat

New 'Rudder Drive'
This news just in...
Torqeedo and Hanse Yachts Launch Rudder Drive

Granted the system is a bit small for 'yachts', and even most of the vessels I am interested in, but perhaps they will improve on size and range with upcoming the tech in battery stowage capabilities.
But check out the maneuverability !!

Silent Chain Drive Leg

After my recent sailing trip aboard the 75' Ppalu catamaran I am reconsidering some thoughts of mine on 'propulsion'. Ppalu has a single 150hp outboard mounted on a skid under the bridgedeck. It is far enough forward of the aft beam that it does not 'jump' out of the water surface that often, even in the good size swells we were in. If I were redesigning or modifying the arrangement, I would provide for a slightly more 'protective' skid, and I would definitely have the outboard motor steerable in unison with the helm/rudders when it was being utilized. Other than that a good old outboard motor was a relatively cheap and useful aux for this vessel.

To take it a step further I would 'divide' the outboard engine up into its powerhead and its drive leg portions. The powerhead portion would be my aux engine in its own very accessible 'box' up on the bridgedeck, and the drive-leg would be a fabricated silent-chain drive unit. That chain drive leg might be a retractable unit like the case of the outboard engine, OR it might be a fixed structure with a folding prop on the shaft. In either case it would be a pretty simple chain driven leg that could be steered with the rudders.

The aux powerhead engine portion might be a lightweight Steyr hybrid engine with its own 'generator' incorporated into the bellhousing.

Hi gentlemen,
I was just reminded that ,many years back, I had intensely looked into a free piston Sterling motor powered by the Suns rays...via big trough collectors....and yhis Freepiston was supposed to move a linear generator...
Nowadays , especially the latter, had become " the dogs bollocks" as a range extender . Toyota has released news of having made one with ,I believe it was over 45% thermal to kW efficiency,and 20kW output and at DLR, a German Areospace research Institute, they also have some running ..with 35 and 60kW el..their combustionchamber is in the middle of 2 oscillating pistons bouncing against a gasspring. Further combustionchambers instead of those springs should increase efficiency....

Long story short: those would make very light, small AND very efficient generators. And with an efficiency of 45% equalling 190 g/kWh.....better than any small boat diesel which lies @ 220 for the best Commonrail and close to 300 for normal inj.

The DLR models are rather small, app 80cm long and 15cmx15cm square...35kW, dont look heavy at all. 30 to 50kg maybe.

Now with this tech I would go for serial hybrid, and still only need the same fuel per nm as the most ideal diesel setup.

Any one of you having better knowledge of this tech?
S