Electric Main Drive(s)

[fastcat435]

The empty weight of the Fastcat 445 Green Motion fully equipped but empty tanks is less than 7700 kilo or 16950 lbs and that includes all needed to sail the oceans

[osirissail]

Wow, that's about - roughly - have the weight of the "other" brand and should greatly help performance and power usage. Just a couple more concept question, por favor.
I noticed in the website that your hulls are "cored" both above and below the waterline, is that true?
Why do you offer the electrics at 12.8 equivalent horsepower versus the diesel engines at 20 hp? Does that make a difference in boatspeed under power?
thank you.

[fastcat435]

Originally Posted by osirissail

Wow, that's about - roughly - have the weight of the "other" brand and should greatly help performance and power usage. Just a couple more concept question, por favor.
I noticed in the website that your hulls are "cored" both above and below the waterline, is that true?
Why do you offer the electrics at 12.8 equivalent horsepower versus the diesel engines at 20 hp? Does that make a difference in boatspeed under power?
thank you.

It is actually a little over half the weight but the FastCat is also 3 ft longer and carries about 30 % more sail. the water line length to width ration is 1: 12.5 so very slim hulls
yes she is cored above and below the water line and below the waterline we have used Kevlar to improve impact resistance , advantages are off course less weight better insulation and no condensation or mildew.
the knowledge we have for the motor ratings are
2 x 4.5 kw Solomons give us 6.5 knots top speed and 2 x 20 hp give us 6.9 knots
2 x 30 is good for 8.0 and 2 x 40 is good for 8.4 knots
we expect to achieve 8 knots with the Green Motion system with full power and we can overboost the system with 30 % power to 12.5 Kw with out problems
With a electric motor power is measured on the shaft with out losses while diesels have transmissions . p brackets, hull bearings and alternators that all use power
Max Torque is also available from 0 RPM and this has the advantage that we can use a larger propeller that turn at a lower rpm setting and that is more efficient than a small high rpm prop.
This large prop is possible since when sailing we lift the motors out of the water to create no prop or sail drive resistance.

[Dedzaboy]

Originally Posted by fastcat435

The empty weight of the Fastcat 445 Green Motion fully equipped but empty tanks is less than 7700 kilo or 16950 lbs and that includes all needed to sail the oceans

I think it's only fair to point out that, unless I'm much mistaken, any weight figures quoted are theoretical since there are as yet no Fastcat 445 Green Motion boats completed and launched.

[schoonerdog]

Regarding charge cycles on batteries, again, Gideon isn't making the claim. Valence Technology, the creater of the batteries, is. U-Charge® RT Lithium Iron Magnesium Phosphate Modules | Lithium Iron Magnesium Phosphate Batteries

[schoonerdog]

Fundamental properties of lithium iron magnesium phosphate, the core of Valence’s Saphion® technology, make for an intrinsically safe cathode material for lithium ion applications currently available. Because this material has a high resistance to the liberation of oxygen, no significant exothermic event occurs upon heating. According to Valence, any Lithium oxide reaction is susceptible to a runaway thermal reaction. Their batteries have also been available for years (I got a quote for some 2 years ago, WAY expensive, but if I owned a really expensive race boat, I'd buy them.)

Originally Posted by Aussiesuede

Actually, yes. The controller for that lithium ion battery in your laptop is purposely degraded in efficiency to keep it safe. Lithium Ion is very unforgiving to voltage spikes and will easily catch fire. Therefore the charge controllers operated at less efficiency to reduce said risk. In doing so, the heat generated is increased - reducing the number of "real world" cycles available.

The advent of lithium phosphates mitigates some of these problems since a voltage fire can be suppressed by the phosphate itself - allowing commercial manufacturers to install controllers that are less resistant - thus generating less heat and giving you more real world life cycles than does lithium ion.

A 20v / 4000ma lithium phosphate battery in your laptop, of the same form factor as your current lithium ion, would yield operating times in about the 10 hour range. The battery doesn't actually have more storage capacity - just more efficient control. When these batteries hit the market in 5 years or so, you'll notice that they still show 3000-4000ma capacities, yet 10 hour run times. The technology exists today - it just isn't cost effective (and won't be until laptop prices bottom out AND there is a wide demand for runtimes longer than the current 3-4 hour standard)




3000 cycles is thoretically obtainable. But in the real world, such a system would never be designed for consumer use that would ever approach this - since the accompanying risk of lithium explosion would be untenable. Therefore, commercial manufacturers will continue to control efficiencies to keep the batteries safe. That means increased heat, which ultimately in turn means fewer life cycles.

If you put a dam in the middle of a river, you create more pressure - and heat. The efficiency of river flow around a dam is less than that of a free flowing river. That lithium controller is basically a dam restricting the free flow of energy (in and out). That restriction will generate more heat.

[fastcat435]

You are mistaken ! Green eMotion was weighted in the factory and the parts missing on the boat like rig sails where weighted separate so we know the weight , the less than 7700 kilos of weight is proven.

[KGP]

Gideon, correct me if I am wrong - this boat is to be yours, correct?

So are the retractable drives already installed on this beast? Haven't seen a photo showing them...

[fastcat435]

Yes you are right she is mine and you will see the retractable drives once she is launched in both pictures and movie,s

If you want you can even come and sail to see if the system and the boat are ok

gideon

[KGP]

Thanks, I'll settle for a video done by Paul after it's been in the water for a while. Perhaps you should extend him the same invite. I hope it's a winner.

[fastcat435]

so do we and enough afford has gone into the system having all designed from scratch and having spared no money or time to get it right.
We will get a professional to do the film and photo shoot for us .There are a few in the Durban area

[Nordic cat]

Here are a couple of pictures from an electric drive 50 footer.

This boat pushes the envelope, not only regarding the drives, but the hulls and rig as well. A-frame mast. No keels or boards.


DESIGN

Is your drive concept based on the same idea Gideon? i.e. the way the drives are mounted. The electrical information is posted already.

[fastcat435]

Gerhard makes a very interesting boat, the electric drives cannot generate electricity so the gen set need to be used at all times, is is a different concept however the way the drives go down is the same way as I see it , more or less the same way as ossolite but with pod drives, I like this better since there is no resistance while sailing.
Most Volvo Ocean boats also had retractable drives made by Amartech in the Netherlands
I feel retraction is the best way to go, no hull penetrations ,no drag no transmission losses and no growth on a prop or sail drive.
Being able to generate while sailing is a step better !

[lurocat]

Hello everybody, just an introduction.
I have been reading the posts for quite some time while looking for the right boat to build and equipment for it.

Nordic cat

Could you post where did u find this retractable drive photos?I had a similar idea for my boat in the future.
I understood it is a SMG 50 but these photos are not posted on the site, is it a custom made? Photo location?
Thank you
Roman

[delmarrey]

I don't know if this has been posted yet but here's a motor that run off of saltwater.

YouTube - Top Gear - General Motors hy wire