PDA

View Full Version : Electric boat motors



TK1
22nd May 2006, 12:53 PM
Hi all,

I am in the process of searching for the right design to start building my first (full-sized) boat. Looking for something around 14' - 18' (so I can build it in the workshop).

Still tossing up between sail and power, although I will probably graduate to a mahogany-runabout style boat after 1 or 2 simpler builds...nice looking and as my son is nearing his teens he is drwn to faster power boats.

I want a small river explorer, open boat I can fish from, day sail, etc. Sorry, getting off the subject a bit...

April issue of Classic Boat has a story about electric-powered boats in the US that seem close to what I'm after. Other option is a wherry/skiff type boat with a small motor. Whilst I'll look at outboards and small diesels, does anyone here have experience with electric motors? I know a couple of the mundoo boats are electric.

Does anyone know of suppliers here? Any experience or comments on them? I like the thought of their quietness for salmon/trout fishing and general peacefullness.

Alternatively, any thoughts or comments on small inboard diesels? Not after speed, more economy.

Thanks in advance,
Darren

onthebeachalone
22nd May 2006, 05:03 PM
This was advertised in AABB #53 Page 12
Contact number was 02 4754 5416
http://www.asmomarine.com/2005/asmo_uk/00.shtml

Any help?

TK1
22nd May 2006, 05:10 PM
Thanks OTBA. I hadn't seen this site so will give it a good read. Haven't commited to electric yet, but it seems a good option (and engine type will dictate some of the interior layout) so all the info helps.

Regards,
Darren

Ashore
22nd May 2006, 06:12 PM
Haven't commited to electric yet, but it seems a good option (and engine type will dictate some of the interior layout)

As will the length of the extension lead and its storage :D

onthebeachalone
22nd May 2006, 06:27 PM
At last weekend's Bribie Island Classic Boat Regatta there were quite a few boats using MinnKota electric outboards, some variously "built in". They seem to be pretty popular for trolling/auxiliary use.

http://www.minnkota.com.au/

But I agree with Ashore, here is still a problem with overall effiency when you consider the weight/storage ratio of the batteries.

Ecca
22nd May 2006, 07:19 PM
Hi Model shipwright, Good move. Much quieter way to go.
Try emailing [email protected] or just Google Lynch electric motors
regards Ecca:cool:

Boatmik
23rd May 2006, 01:49 PM
Vetus has one which includes a propellor shaft and shaft bearings and seals.

Sort of an all in one - drop-in unit. Probably quite expensive - but may work out OK if you take into account all the bits sourced seperately for a motor bought seperately. It is about 3hp I think.

Vetus is generally distributed through ship chandleries or can be contacted through
www.vetus.com - they have an office in Qld - 07 3356 9808

jmk89
23rd May 2006, 01:59 PM
Probably quite expensive

I had a look at the website just of interest - the electric moter alone is 3,990 euros (then add transport and GST). Ouch.

The price for quiet.....

TK1
23rd May 2006, 03:48 PM
Hi,

Thanks to those that replied. I have checked out some of the websites suggested and also done a bit of a web search on electric motors.

Based on price, battery life and availability, I think I'll learn to enjoy cruising down the river to the sound of a small diesel engine...and the change in my pocket!

So now to investigate small, second-hand (and hopefully old) diesels for installation. I may be getting ahead of myself, but I want to do some motoring and as it won't be a large boat then I need to consider engine size, fuel tanks, etc in the design. (I've rebuilt Land Rovers so figure a small diesel won't give me too much trouble).

Will be sure to keep people posted on the search and post pics once the long-awaited building starts. Will keep dreaming of being given a free classic wooden motor yacht in the meantime...

Regards,
Darren

Boatmik
23rd May 2006, 05:22 PM
I am working from Duck Flat thisafternoon

The permanent magnet motors of the type they use for the Mundoos start at $2500. Adding a controller brings it up to about $5000.

MIK

TK1
23rd May 2006, 05:30 PM
Hi Mik,

Thanks for the prices. I am actually considering one of the Mundoos as a second or third project - wanted to do something smaller first that won't require extending the shed (or scaring the wife) but as one goal is to cruise the likes of the Murray, they certainly have appeal.

$5K isn't too bad for a full setup, but for the smaller boat I may try to pick up a little inboard or outboard. Or I'll stick with sails :)

Regards,
Darren

PS Hope you're having fun at Duck Flat while some of us are stuck in cubicles in the city :(

Auld Bassoon
23rd May 2006, 07:47 PM
Hi Darren,

If you are planning a small river craft to start with, why not consider an electric trolling motor?

If you're set on a small Diesel, I have had good experiences with the small Yanmars: reasonably quiet, very smooth and economical.

WRB
24th May 2006, 07:44 PM
Here are some good powerboats for a beginner:

http://www.woodenboatstore.com/prodinfo.asp?number=400-071

http://www.woodenboatstore.com/prodinfo.asp?number=400-077

and when you get really good at it:

http://www.woodenboatstore.com/prodinfo.asp?number=400-098

I actually have a set of plans for one of these....

cheers

TK1
25th May 2006, 10:08 AM
Hi WRB,

Thanks for the links. I am actually looking at some of the Zimmer designs or another mahogany runabout type powerboat. Nice lines and would be fun to zip around in.

I'll have a look at the other ones too, they look like simple ones to build and would be a good intro into the harder designs.

Regards,
Darren

Boatmik
25th May 2006, 12:42 PM
Here are some good powerboats for a beginner:

http://www.woodenboatstore.com/prodinfo.asp?number=400-071

http://www.woodenboatstore.com/prodinfo.asp?number=400-077

and when you get really good at it:

http://www.woodenboatstore.com/prodinfo.asp?number=400-098

I actually have a set of plans for one of these....

cheers

Howdy,

I am not sure if these boats are suitable - nice boats - but remember we are talking electric powering.

Here is how to work it out for yourself.

Choosing a hullform for low power use
Be aware that for electric propulsion (and other low power forms - small outboards, sail, rowing) it is best if the bottom of the boat comes up to the waterline or above for minimum drag.

Some of the boats have the bottom of the transom well immersed so will have excessive drag at low speeds.

Rowing or sailing boat derived shapes make the best choices. They are both efficient with low levels of power

Some rowing boats have very fine sterns which means that the boat will sit significantly bow up with an outboard and operator in the back.

Sailing boats which tend to have moderately wide sterns which might be more suitable. They will also move quite smoothly into a planing regime which allows them to go a bit faster than a proper rowing hullform. Though they have problems if overpowed significantly (below)

You don't want the stern to be tooooo wide either as it can lead to wild steering in a seaway (because of excessive buoyancy in the stern compared to the bow - bow sticks in at speed and stern attempts to overtake it) or when the boat is strongly heeled.

More Power
The downside of such hulls with the bottom coming up to the waterline (or as we say in the trade - no or little immersed transom) is that higher powers that get the boat up toward planing speed will cause the bow to rise high in the air as the stern sucks down because of the aft bottom curvature.

This can be sorta good if not too dramatic as it does stop the bow from sticking in suddenly but can stress the bottom with pounding loads. At higher speeds still the bow rises crazily in the air and the boat becomes very inefficient indeed.

That is why you have to decide whether your boat will be going at planing speeds or displacement speeds when you choose the design. Choose the wrong one and you end up with a non-optimum solution.

Boatmik

TK1
25th May 2006, 12:52 PM
Hi,

Thanks for the words of advice. If I did build a Zimmer,/Hacker/Chris Craft type runabout I'd certainly go for a serious diesel motor - no sense having a 'gentleman's runabout' that only does 4 knots!

The electric motor choice would be for alternative or main power - depending on the style of boat selected - and would be of the traditional electric launch style or backup power for a sailing skiff or sharpie or similar. I don't mind the canoe-stern and other launches that David Payne does and I thought one of these may suit an electric rather than petrol/diesel motor. But if I can get a nice old motor that chugs along (and I'm happy to rebuild one) then this could be as appealing asa quiet electric motor. Just might scare the trout away!

I appreciate to comments on design and I'll certainly aim to select a style that does what I want, and for which it is intended, and will most likely call on Duck Flat for help (and to buy the plans from ;) )

Regards,
Darren

Solarboat
20th June 2006, 09:57 PM
We have a range of electric boat motors, ranging from fractional horsepower to about 10kW, including inboard, outboard or "sail drive" type power pods.
We also can advise on suitable small boats (16-25ft) for electric drive.
Basic info is on www.solarboat.com.au (http://www.solarboat.com.au) (currently about 2 years out of date - why does updating the website always come behind other projects??

We have plans for a nice little 15ft clinker launch - half cabin design coming up.

If we can help further contact [email protected]

TK1
21st June 2006, 09:55 AM
Thanks "Solarboat".

Let me know when the 15' design is done via [email protected] as this could be of interest.

I'll check out your website and be in touch if I go down the electric path.

Regards,
Darren