Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 11-02-2015, 21:27   #76
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,940
Re: Using electric motors instead of Diesel on your cat

Quote:
Originally Posted by BigBeakie View Post
[IAbout torqeedo... they design their products to recharge on a dock, not to run on solar power. This is a fact and you should consider this when evaluating what they have. You will also find you can build a more efficient custom unit for a fraction of the price.]"[/I]

Not true, it is not a fact. The Deep Blue controller can input shore power, solar & generator. And their hybrid system can take any input including regeneration.
I'm not as familiar with their little outboard product range, but they also can take solar input, as least some of them.

I have checked as many vendors as I can, and Torqeedo is the most efficient motor (54%, input kW to output kW) that I could find and they publish the figures, unlike other vendors who do not publish any tested efficiency data.

I would be happy to learn of others with comparable tested efficiency, what are they?
Sure they can charge off solar. But figure out the size and cost of the solar system you need in order to drive one. Let's assume a relatively modest 4kw/hr draw from the system over the course of the day. When you spec out the size of the panels you need to power this you will be suprized how big a boat you will need to build just to mount it.

Assuming no efficency losses you will need...
4kw/hr*24hr=96kw.

Commercialy available 20kw/day solar arrays run about $40,000. So for about $200,000 you can motor along at 3kn all day every day. But you also need about 500 sq foot of unshaded deck space to install them on. And some way to account for all the weight.
__________________

__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Old 11-02-2015, 21:48   #77
Registered User

Join Date: Jan 2014
Location: Sydney, NSW
Posts: 682
Re: Using electric motors instead of Diesel on your cat

Quote:
Originally Posted by cwjohm View Post
Calder is quite clear on the issue of Hybrids after testing for five years in that he states that they are not more efficient than conventional diesels.

For an alternative view see

The Science of Hybrid Propulsion: The Great Debate | | PassageMaker

As I see it the problem with the comparative densities of diesel vs battery is that you have to jump through extensive technical hoops to make a battery based system viable. Yes of course you gain the benefit of using solar capacity on motoring but the average cruiser does not have significant solar capacity left over after other uses. Loading up with the required solar arrays (many KW) and batteries (many kw) means significant additional weight. Further the complexity of separate battery systems and charging regimes makes for a very complex system.

What will make this viable for the average cruiser is firstly the incorporation of the generator into the motor and secondly an order of magnitude increase in energy density of batteries.

I do agree with the point made by someone here that mostly this is a matter of stepwise evolution, although I think there are some quantum leaps to be made in battery technology.

Yes, Calder does conclude that from a strictly motoring efficiency POV, fossil fuels deliver on that front, but he also makes the point in the Practical Sailor article that for motor sailors that would a major factor, but for sailboats he states that the benefits of serial electric may well outweigh the motoring efficiency issue.

That is certainly my perception, for our intended cruising plans.

And whether you invest in solar & batteries vs liters of diesel, weight wise, is a judgement call based on expected useage of the boat, cruising location and diesel availability etc. as well as the secondary benefits that have qualitative value such as not running generator in anchorage, no fumes, running electrical appliances, not ferrying jerrycans of diesel etc.

Monohulls would struggle to get enough solar, I agree, but cats are a different matter. We believe we can get 2kW quite comfortably, and our energy budget analysis ( there's the dreaded spreadsheet, Chris ) is looking pretty positive.
__________________

__________________
BigBeakie is offline   Reply With Quote
Old 11-02-2015, 22:21   #78
Senior Cruiser
 
44'cruisingcat's Avatar

Cruisers Forum Supporter

Join Date: Sep 2006
Posts: 7,459
Images: 69
Re: Using electric motors instead of Diesel on your cat

If you're really going all electric - ie electric cooking, hot water, barbecue, electric motor on the dinghy, etc, you're going to find your 2kW of solar barely enough for house loads. And if it's cloudy, it could be cold showers and food....
__________________
44'cruisingcat is offline   Reply With Quote
Old 11-02-2015, 22:43   #79
Registered User

Join Date: Jan 2014
Location: Sydney, NSW
Posts: 682
Re: Using electric motors instead of Diesel on your cat

44CC,

Yeah the BBQ is a killer! I have no data on how many amps electric BBQ would draw, but it has to be mega. And I think we'd like to BBQ alot, if the fishing is any good.

I have recently had a good demo of induction cooking for the galley cooktop and energy use, and it seems very promising. Basically you zap the pan for a short time and then it cuts way back on power draw, with Bosch and Siemens looking like the leaders.

But yeah, amps in amps out

I was very pleasantly surprised to learn about Ozefrigde gear and it's proven power requirements. Much lower than I had expected, so at least there is some good news.
__________________
BigBeakie is offline   Reply With Quote
Old 11-02-2015, 23:26   #80
Registered User

Join Date: Apr 2013
Posts: 4,890
Re: Using electric motors instead of Diesel on your cat

Quote:
Originally Posted by cwjohm View Post
What a load of rubbish. Electronics started with silicon doping invented in the 1950s and the internet started in the 1970's.

Were you not around for the dot com boom where supposedly all of these great innovations on the internet crashed and burned. It is only in the last five years, nearly 10-15 years after the ideas were first raised that the actual results have been seen in terms of commercial success. How long did it take for Microsoft to get an operating system that was reliable. Over ten years.

Yes, software now has a faster turnaround time, and electronic innovations like mobile phones are much quicker, but we are talking billions in R&D commensurate with market demand.

The Airbus was based on design elements that go back 20-30 years. To say that it went from first design to handover in ten years is just wrong.

To state that an electrically propelled boat is based on off the shelf components is again wrong. In any complex electromechanical system involving mechanical drives, electrical systems, electronics, software, and battery technologies there are several areas of innovation that link these elements together. Sure, as with anything you can cobble something together but it does not constitute a properly developed product that will reflect reasonable levels of reliability.
Also, working in the traffic industry, our controllers are typically 10-20yr old technology because of the safety risks if the latest and greatest had a flaw. It was only about 5yrs ago that the systems I work on went beyond 1200baud for comms.
__________________
valhalla360 is offline   Reply With Quote
Old 11-02-2015, 23:28   #81
Senior Cruiser
 
44'cruisingcat's Avatar

Cruisers Forum Supporter

Join Date: Sep 2006
Posts: 7,459
Images: 69
Re: Using electric motors instead of Diesel on your cat

There are some quite efficient ways to heat water, but even at 100% efficiency, it still takes about 1.2 watt hours per degree per litre.


Work out how many cups of coffee, litres of hot shower water, cooking water, etc you'll use.


Then there's things like making toast, or cooking a roast.....
__________________
44'cruisingcat is offline   Reply With Quote
Old 11-02-2015, 23:39   #82
Registered User

Join Date: Jan 2014
Location: Sydney, NSW
Posts: 682
Re: Using electric motors instead of Diesel on your cat

Let's not even think about the Admirals washing machine

I'm in trouble now, she reads these posts from time to time.....

Yes honey, I know you need a washing machine
__________________
BigBeakie is offline   Reply With Quote
Old 11-02-2015, 23:40   #83
Registered User

Join Date: Mar 2013
Location: Mooloolaba
Boat: Helia 44
Posts: 470
Re: Using electric motors instead of Diesel on your cat

OK, so let us calculate the practicalities, assuming what Calder says about efficiencies is correct.

Let us assume based on what you have told us.

2KW solar
1 KW battery on each engine
30KW Electric motors

You will use 1Kw per day solar on general usage of the boat.

You are going to install 30KW motors (60KW). Let us use your number of 50% KW usage for electric, and let us assume (whilst motoring) you are using on average half of that power. Let us be conservative and say 10Kw/h. I know you will disagree. Substitute your own number.

This means that in effect you will get around 15 mins operation (battery and solar) when motoring is needed before the generator cuts in assuming you are not pushing the boat. I know you will say that you are happy to motor more slowly but we really need to compare apples to apples here. Based on data supplied here the AVERAGE cruiser uses around 2h per day. Yes, I know you will maintain this is high. Substitute your own number. The reality is that whilst you are motoring the generator will run most of the time, and all of the problems of the pesky diesel will remain.

Then to calculate generator sizing. This will be based on maximum power. When you really need to put on the power you will need both motors totalling around 50Kw/h so this determines the sizing of the generator you will need. Yes I know you will maintain the 50KW/h is overkill but substitute your own number. In any case it will be one big generator.

So what do we have in summary.

A boat which runs quietly with none of the diesel issues for a short time but most of the time will require a diesel generator with all of its commensurate problems. All of the issues you state in regard to diesel (all of which are imaginary by the way) in the Pacific will still be there.

Balanced against that you will have a complex system which few will understand. There will have to be a control system so that when a motor is off the generator will charge the batteries for that motor and still allow for charging by solar. You will have mppt regulators on each system along with a control unit which handles this, as well as an inverter which will I assume able to be slaved off either battery. You will have two battery banks each having an intelligent monitoring device and you will have to manage the power in each bank depending on usage.

You will have difficulty finding anyone to install it and maintain it because the electronics and wiring will be so complex. Any fault will be very difficult to troubleshoot.

On top of this you will have 2 electric motors, 2KW solar and 2 1KW battery banks and larger props. A lot of weight and a lot of drag. Your supposedly light boat will become heavy and together with larger props sailing performance will be heavily compromised.

I do not expect you to agree with me because as far as I can see any cogent argument put here is responded by you as FUD. So I work through this for my own purposes as like many others I would dearly love to install one of these systems in a future boat. One day I believe I will, but not until such time as I can get 10KW of solar effectively and cheaply installed and battery energy densities are improved from the current .4KW/h to around 10KW/h both are which are eminently achievable in the next 10-15 years.

I hope that I will live that long.
__________________
cwjohm is offline   Reply With Quote
Old 11-02-2015, 23:45   #84
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Re: Using electric motors instead of Diesel on your cat

I follow this technology. Here's my view.

Battery size and technology are actually irrelevant. Power generation ability is the key. In practice your power generation system must be capable of meeting the average continuous demand, over the length of time you design the system for.

To date other then using diesel generation, I've not seen it successfully done on a cruising boat. I see no point in having a diesel on board and not using it for propulsion directly.

Batteries are a store , they are there to achieve peak usage from average power generation, they are not a power source. When we have solar or other power generation approaching the density of hydrocarbons , the. Electric drives will be not only practical but better then IC engines.
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 11-02-2015, 23:57   #85
Registered User

Join Date: Jan 2014
Location: Sydney, NSW
Posts: 682
Re: Using electric motors instead of Diesel on your cat

Quote:
Originally Posted by cwjohm View Post
OK, so let us calculate the practicalities, assuming what Calder says about efficiencies is correct.

Let us assume based on what you have told us.

2KW solar
1 KW battery on each engine
30KW Electric motors

You will use 1Kw per day solar on general usage of the boat.

You are going to install 30KW motors (60KW). Let us use your number of 50% KW usage for electric, and let us assume (whilst motoring) you are using on average half of that power. Let us be conservative and say 10Kw/h. I know you will disagree. Substitute your own number.

This means that in effect you will get around 15 mins operation (battery and solar) when motoring is needed before the generator cuts in assuming you are not pushing the boat. I know you will say that you are happy to motor more slowly but we really need to compare apples to apples here. Based on data supplied here the AVERAGE cruiser uses around 2h per day. Yes, I know you will maintain this is high. Substitute your own number. The reality is that whilst you are motoring the generator will run most of the time, and all of the problems of the pesky diesel will remain.

Then to calculate generator sizing. This will be based on maximum power. When you really need to put on the power you will need both motors totalling around 50Kw/h so this determines the sizing of the generator you will need. Yes I know you will maintain the 50KW/h is overkill but substitute your own number. In any case it will be one big generator.

So what do we have in summary.

A boat which runs quietly with none of the diesel issues for a short time but most of the time will require a diesel generator with all of its commensurate problems. All of the issues you state in regard to diesel (all of which are imaginary by the way) in the Pacific will still be there.

Balanced against that you will have a complex system which few will understand. There will have to be a control system so that when a motor is off the generator will charge the batteries for that motor and still allow for charging by solar. You will have mppt regulators on each system along with a control unit which handles this, as well as an inverter which will I assume able to be slaved off either battery. You will have two battery banks each having an intelligent monitoring device and you will have to manage the power in each bank depending on usage.

You will have difficulty finding anyone to install it and maintain it because the electronics and wiring will be so complex. Any fault will be very difficult to troubleshoot.

On top of this you will have 2 electric motors, 2KW solar and 2 1KW battery banks and larger props. A lot of weight and a lot of drag. Your supposedly light boat will become heavy and together with larger props sailing performance will be heavily compromised.

I do not expect you to agree with me because as far as I can see any cogent argument put here is responded by you as FUD. So I work through this for my own purposes as like many others I would dearly love to install one of these systems in a future boat. One day I believe I will, but not until such time as I can get 10KW of solar effectively and cheaply installed and battery energy densities are improved from the current .4KW/h to around 10KW/h both are which are eminently achievable in the next 10-15 years.

I hope that I will live that long.
Just to jump in with corrections. The propulsion batteries are 13kW each, one per side. Not sure how big the Lithium house bank will be yet, I assume about 400 amphours, probably more? It is separate from the propulsion batteries. There will be approx. 6kW used in cruising mode by one motor at a time, giving about 2 hours motoring at cruising speed. There is a 6.4kW Aussie developed generator (that is a ripper) that will charge the batteries via 2 3kW chargers. So while one battery is being used motoring, the other is charging. When it is fullish, we swap over. Repeat as necessary.

Just so we can work scenarios that represent what the system actually consists of.
__________________
BigBeakie is offline   Reply With Quote
Old 12-02-2015, 00:59   #86
Registered User

Join Date: Mar 2013
Location: Mooloolaba
Boat: Helia 44
Posts: 470
Re: Using electric motors instead of Diesel on your cat

2 lots of 13KW propulsion batteries??
6Kw cruising
6KVA generator at peak load.

OK, I give up. The laws of physics are obviously different in your universe. Let us know when it is complete.
__________________
cwjohm is offline   Reply With Quote
Old 12-02-2015, 13:11   #87
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,940
Re: Using electric motors instead of Diesel on your cat

I'll try a different tack...

Let's assume you are ok motoring along at 3kn as your crusing speed in dead calm conditions. Which is about what you have, and eventually figure out that you can charge and use a battery bank at the same time, which in this application you should. Finally let's assume that we ignore battery efficency and Peukers law and all the other technical stuff for a few minutes....

What happens when you drag anchor and need to reset in a 50kn headwind? Pulling 30kw from a 15kw battery back to make headway gives you about 15minutes before you are out of juice. But to do this you have cooked your batteries and will need replacing. And then if your batteries will even accept a charge again it will take you at least 10 hours of generator run time to get them back to a usable state.

So if you drag again your boat will be lost. Because despite all your equipment worki fine, you have no sutable source of power for your primary engines.

What Nigel recommends would effectively be the electrical system you contemplate but with 6kw drive motors. With 30hp diesels hooked up to the drive shafts when you need real power. Or a small generator (like a 10kw) for house / light propulsion needs and a 60kw generator for when you need real power.

My issue with Calder is that his system is stupid. His numbers work, but the designes overly complicated. If I were designing an electric propulsion boat I would go with a small generator for house/light propulsion, a big battery bank to run house loads when the generator isn't on, and then a massive drive generator for when you need cruising speed.

I don't think this system is worth the investment, but at least on paper it sort of works.
__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Old 12-02-2015, 17:09   #88
Registered User

Join Date: Jan 2014
Location: Sydney, NSW
Posts: 682
Re: Using electric motors instead of Diesel on your cat

Quote:
Originally Posted by Stumble View Post
I'll try a different tack...

Let's assume you are ok motoring along at 3kn as your crusing speed in dead calm conditions. Which is about what you have, and eventually figure out that you can charge and use a battery bank at the same time, which in this application you should. Finally let's assume that we ignore battery efficency and Peukers law and all the other technical stuff for a few minutes....

What happens when you drag anchor and need to reset in a 50kn headwind? Pulling 30kw from a 15kw battery back to make headway gives you about 15minutes before you are out of juice. But to do this you have cooked your batteries and will need replacing. And then if your batteries will even accept a charge again it will take you at least 10 hours of generator run time to get them back to a usable state.

So if you drag again your boat will be lost. Because despite all your equipment worki fine, you have no sutable source of power for your primary engines.

What Nigel recommends would effectively be the electrical system you contemplate but with 6kw drive motors. With 30hp diesels hooked up to the drive shafts when you need real power. Or a small generator (like a 10kw) for house / light propulsion needs and a 60kw generator for when you need real power.

My issue with Calder is that his system is stupid. His numbers work, but the designes overly complicated. If I were designing an electric propulsion boat I would go with a small generator for house/light propulsion, a big battery bank to run house loads when the generator isn't on, and then a massive drive generator for when you need cruising speed.

I don't think this system is worth the investment, but at least on paper it sort of works.
Ok Greg, good idea, let's try a different tack. Let me lay out how this has been put together so we can assess whether it looks like it will do the job, or not. And I am more than happy to hear from those who have a viewpoint based on meaningful analysis ie from direct experience or professional knowledge or real world data. Let's keep the FUD opinions out of this, because it really is not helpful. I am hear to learn, not to be a fanboy of any particular technology. On the other hand, if I am wrong, prove it. Don't expect me to just believe your opinion because you say so. OK?

From hull resistance work and real experience with performance on a sister ship with 39HP Yanmar shaftdrives and Brunton Autoprops, we believe the 30kW electric will produce 6 knots on flat calm with the right size and pitch Kiwiprop for electric using one motor. OK? Lets assume this is true. Kiwiprops feather very nicely, so no more rubbish FUD about dragging around bigger props, OK?

Then we are cruising at 6 knots using 6kW/hour (from a known rpm at a known torque spinning a known propeller spec) which means we can cruise for approx 2 hours until the 13kW Lithium propulsion battery is flat. Yes I know it should not be flattened but kept to 80%DOD.

At that point we start the 6.4kW diesel generator or the 6.5kW petrol Honda (haven't decided which yet) and charge the now depleted battery with 2 (two) 3kW chargers, which should take about 2 hours to rechage. Right? We are now running on the other side motor and battery for the next 2 hours. and so forth, OK?

When the 50 knot wind causes us to drag at anchor we can apply full throttle for about 30 minutes from each motor ( 30kW from 15kW battery), BUT and this is the point I want to make, it will not be necessary to use full throttle because the thrust developed by the high torque electric motor and bigger higher pitched prop will push the boat against the wind without needing to use full throttle.

This seems to be the point that is hard to get across, so let me try an analogy and see if that works.

Let's take 2 extremes. Two boats, one has a 10HP outboard with its normal prop (WOT is say 5,000rpm) and one has a 10HP electric with bigger higher pitched prop (WOT is 2,000 rpm). Stand up to your waist in the water pushing against the bow as the driver puts the outboard in gear and motors against you. Feel the force pushing against you. Get the driver to increase revs slowly until you cannot hold the boat back any longer. Now do same thing with the electric. Take note of the revs of each boat at the point when it would push you over.

What would the result be? I maintain that you would be pushed over by the electric motor at much lower revs than the petrol outboard. I maintain that the outboard will go much faster (planing hull form) at WOT with it's smaller but faster rpm prop than the electric boat at WOT with the bigger, higher pitched, but slower rpm prop.

Furthermore, and this is the main point, I maintain that the electric boat will be able to maintain its lower maximum speed against a bigger force (like the wind) than the outboard, which will slow down more against the wind.

So the point re EP cruising boats is that the electric can be run at lower rpm, and hence less energy drain from battery giving longer run times and range, and still cope with adverse wind and wave conditions.

So it seems to me that with adequate solar, adequate lithium house bank, good generator charging system, reliable EP system from top quality components with built in diagnostics, and a vendor who stands behind the entire system (meaning they fix it no matter what!) regardless of what may develop a fault, it seems to me this has to be taken seriously as a viable cruising EP solution offering many, many advantages.

I am prepared to be convinced otherwise by argument based upon real data or other evidence. If I am right, this is really good news, it seems to me. If I am wrong, then there must be a fault at principle, not execution. Meaning there may be technically inadequate spec somewhere, but that can be modified or fixed. But if the EP system has adequate power motors and sufficient propulsion battery to deal with adverse scenarios, and has reliability & support, then it would seem to be a serious contender.
__________________
BigBeakie is offline   Reply With Quote
Old 12-02-2015, 17:32   #89
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,940
Re: Using electric motors instead of Diesel on your cat

1) How do you go from needing 30kw to drive at 6kn to 6kw to drive at 6kn? Shaft hp requirements are the same regardless of the type of propulsion motor. In fact the type of propulsion is immaterial to the power required to turn a shaft at a given speed.

If a boat requires 30kw of shaft power to move at 6kn it will always require 30kw of shaft hp to move at 6kn. No change to the propulsion device effects this.

2) As discussed above, which you refused to appreciate. In order to get more thrust at a lower rpm you have to use a MUCH larger prop. The only thing that changing to a larger prop does is effect the slippage rate, it has nothing to do with overcoming the force of the wind. So if the wind is applying a force equal to 20kw of power in one direction it will take a static force of 20kw of force applied in the opposite to keep you still. It could be a small prop spinning quickly, or a large prop spinning slowely but it takes the same amount of input force.

3) if you take a smaller prop and spin it at the same speed as a large prop of course the larger prop will generate more power. However if you take a small prop and apply 10hp to turning it, and you take a large prop and apply 10hp to turning it the output power will be pretty close to the same (the difference is in prop efficiency, which for reasonable options is minimal).

And keep in mind almost every sailboat made uses the largest prop possible given shaft location. To increase to a prop large enough to make much of a difference you have to redesign the boat.


Finally: you are wrong. Electric power does have some advantages. The prototypical case is a boat that is only day sailed, has a short distance to travel in and out of the harbor, and then returns to the harbor to be recharged at night. The further you go from this ideal the worse the trade offs are. For a cruising boat they are immense, which is why there are almost no cruisers using electric propulsion, and why every major manufacturer has backed out of projects to deliver them.
__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Old 12-02-2015, 17:56   #90
Registered User

Join Date: Mar 2013
Location: Mooloolaba
Boat: Helia 44
Posts: 470
Re: Using electric motors instead of Diesel on your cat

Quote:

I am prepared to be convinced otherwise by argument based upon real data or
other evidence.
No you are not. You refuse to acknowledge the reality of people who live in the real world and cruise every day.

By the time your 46" cat is loaded up with all of this stuff it will be about the same weight as any other similar boat of the same size.

My boat for safe cruising in any number of circumstances requires 30Kw PER MOTOR at the prop. Yes, lighter and faster boats may get away with down to 20Kw, but 6Kw is simply fanciful.

Kw at the prop is the same for electric and diesel as Greg notes. This is a matter of simple physics.

On a 46" cat when you are motoring into a 40kn blow on the nose and a 3m swell you are going to need both motors for at least 60Kw to have a margin of safety.

So I put this proposition to you. Go out on a cat of this length, and confine the revs on a single motor to 6Kw as per the torque curve and see how you go. That is if you can find someone who will do this as it would be unsafe in the extreme.
__________________

__________________
cwjohm is offline   Reply With Quote
Reply

Tags
diesel, electric, electric motor, motor

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Using brush instead of spray for gel lancelot9898 Construction, Maintenance & Refit 4 23-06-2013 21:16
Elecric motors on catamaran instead of diesel Bsimon Engines and Propulsion Systems 8 11-05-2012 20:02
For Sale: Electric Motors and hydraulic electric lifter arms 4 sale Sea Shoes Classifieds Archive 0 25-03-2012 08:46
Anyone Using / Heard of Duramax Ultra-X Stuffing Material (Instead of Flax) Northeaster Propellers & Drive Systems 9 11-01-2010 06:21
Found this sight about many types of electric motors to power boats videorov Electrical: Batteries, Generators & Solar 1 18-03-2008 06:15



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 10:17.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.