Electric or Hydraulic propulsion system for small boats

thanks for the links Brian...

 

cost vs weight

Indeed some of the the electrical pieces are big nut parts could more readily available that you choice of hyraulics. I had a vovlo system in the Carribean and ended up waiting several weeks for parts from Miami. In a sail boat config. There is an electric-generator drive unit that works both ways, it charges your bateries while you sail. and propells you with a genset. Nice if can sail a lot. The biggest cost I encountered with my Hydraulics was the cost to replace hoses, they ain't cheap and rare as hens teeth in the 3rd. world. You can get wire and amatures rewound just about anywhere.
You plan for a long haul ocean voyage, get the most of the spares you can afford and when it is all said and done,you get home with a bunch of rusty spares. See my site www.robandmarlane.com

 

Electric pod (Sail drive)

I've found this 20 kW electric pod (Sail drive) from Germany, seeming able to go up to 30 kW:
http://www.kraeutler.at/SD 20kW_e.htm
They have a wide range of electric propulsion systems for boats.

 

"You can get wire and amatures rewound just about anywhere."

Perhaps , but the electronic controlls are going to come from a single source who KNOWS he has "Got YA!"

Hyd is really competative worldwide spairs are easy to purchase and carry and other brands can always be substituted.

So all thats left against Hyd is "efficency" and cost (compared to cheap std drive).

For a canal cruiser that needs maybe 6 hp to go 6mph , the cost of producing 8hp should not be much of a problem , even though system efficency might "only" be 75%.

The use of Hyd to operate other gear aboard easily compensates .
When an electric winch or bow thruster is overused , smoke comes out .
When hyd is overloaded it just stops till the load is reduced.

FAST FRED

 

The controls are not mutch off a problem, a good electician can normaly fitt controls from another manufacturer with no problem.

Moust controls today follow standards off 4-20mA or 0-5V unless it's digital.

 

All of this stuff is availble online via fed ex or dhl. The controls are the most reliable part.

 

Robbie,

Indeed, most stuff is available online, but you can't find it if you don't know where to look. Plus, and this is the important aspect, getting real life opinion instead of marketing hype is pretty important. After all, this is a discussion forum, and other people's opinions are rather important (at least in my opinion).

Why don't you post some of that online content, and give your opinion on it, see if you can find "The shizzle" (lol) for the thread starter. And perhaps share your opinion with us.

Andre

EDIT:

P.S. What does DHL and Fed Ex have to do with anything? They just ship it if you pay them. The only product they sell is a service to deliver whatever you want to send.

 

The efficent motors have computers that know where the rotor is at all times and vary the pulse to vary the power.

Not sure someone elses controlls would work , but I'm not an electrican..

FAST FRED

 

Fred- I've used NGM three-phase BLDC controllers of the type you describe, and will soon be dealing with a Tritium WaveSculptor of similar output characteristics. Great machines, but really pricey - A 5 kW BLDC controller is worth around $4,000 to $6,000 CDN (granted, the things are 97-98% efficient).
Generally, most controllers designed for the motor architecture you are using can be used, regardless of manufacturer, provided that waveforms, impedances, inductance ratings, and all those other technical parameters are fairly close to ideal values.

 

A 5 kW BLDC controller is worth around $4,000 to $6,000 CDN (granted, the things are 97-98% efficient).

While not as "efficent" the entire hyd SYSTEM would cost less than a single controller.

FAST FRED

 

Bagger
I'm a sailor, it is a matter of function and reliability rather than theory and Blah, Blah. If you don't know where and how to get parts for your boat -Don't go to sea. Obviously you have not or had your boat break down in some little corner of France or the Turks and Caicos. My catamaran had a twin volvo HD drive, the pump popped 8 weeks later it was working again.

Everything will fail at sea. How easy it is for YOU! to repair and how readily the parts are is very important. All of that media hype on line also tells one of distribution and reliability. www.whisperprop.de These guys are on the right track. D-E power is ideal for the live aboard, one motor supplies energy to all systems. One set of spare parts. The weakest link to all electrical applications marine and otherwise is energy storage. The battery technology is the weakest link. How about that for opinion?

 

If you're going for top-end high efficiency electrics, this is certainly true.
If you can tolerate 80% efficient electrics, though, the cost comes down an order of magnitude. Yes, the hydraulics will probably be cheaper, but I think I come out in favour of electric here. Of course, for overall best efficiency one would use a plain shaft drive.
EDIT:
If anyone's interested in the latest generation of motor controllers.... http://www.tritium.com.au/project/project.html , Tritium's 30 kW WaveSculptor is due to be released shortly.

 

Yup, good to have an opinion, although I could do without your assumptions about me.

However, what I was commenting on was you going "Everything is online, you can get it through DHL" or something to that end. Now, that is not advice, imo, that is just stating the obvious. Yes, nowadays, what can't be found online? That was my whole point. And, like you just said, getting parts is indeed important, and also a reason for keeping things simple. I fully agree (and am still pissed about your assumptions about me).