GreenCat 605 with retractable electric propulsion

[fastcat435]

Recently the first GreenCat 605 was launched with dual 20 Kw retractable Green Motion Motogens.
after the initial testing of the propulsion system the boat reaches a top speed under power of 8.6 knots ( flat water no wind ) and the power consumption is 46 Kw at that speed.
When the speed is dropped to the eco level of 5 knots the consumption drops to 6 Kw per hour. with this speed we can run for 8 hours before having to start the generator.

below a link to you tube showing the new system

http://www.youtube.com/watch?v=L40nhb0d7M8&feature=plcp

 

[kerosene]

Youtube link didn't work for me.

 

[fastcat435]

I tried it again this morning and it really works on this side .

http://www.youtube.com/watch?v=L40nhb0d7M8&feature=plcp

 

[kerosene]

motors look compact for 20kw. Are you "over powering them" to get 46kw at the top speed?

Link worked now btw. I was on a ipad when it failed who knows why it didn't work.

Your battery pack gives 6kW*8h= kWh effective capacity? That is a pretty massive battery bank - what does it weigh?

System looks good.

 

[fastcat435]

Hallo kerosene

the total powered consumed for 2 x 20 KW electric motors is 46 Kw in one hour , the motors are not overpowered , we could enter a boost setting to get 25 Kw out of them but so far no need to do so.

We use Lithium batteries and the total capacity is 52 Kw for the propulsion batteries , the weight for these 12 Mastervolt Batteries is 780 kilo and another 350 fo the house or service batteries ( 26 Kw lithium )
The weight of each motor is 62 kilo or 135 lbs made from a alloy titanium seawater corrosion resistant. we did more gtersting and we actually consume a bit under 5 kw at 5 knots of speed

In the next cat we will launch we are changing batteries from Mastervolt to another brand to save over 400 kilo,s of weight for all the batteries installed and on top of that 10 % more Kw available , the batteriy technologie is really helping a lot.

greetings

 

[kerosene]

2x20=46? I guess the 46kw is draw on batteries then. Not nitpicking about the last 6kw - just curious.

For future's sake can you use correct units. As in kW vs. kWh - there is already enough confusion about these. I am sure you get the difference but for sake of clarity and accuracy using wrong terms/units is harmful.

That is an impressive battery bank. Cannot be cheap but I guess neither are modern turbodiesels. Can you share a rough price range for such a battery + management system.

Good on you. I don't think this is for everyone and the cost is still border line prohibitive I would think.
Also generally to me battery systems make more sense in applications where they get used frequently and somewhat set amount so the bank can be optimized for the use. I mean use like commuting vehicle that uses 60-80% of battery range EVERY DAY.
On a pleasure boat you have quite a bit of cash sitting for your 20 days of use. I guess that is the case for many components in a pleasure boat though.

 

[fastcat435]

Hallo kerosene , yes the 46 Kw is the actual consumption for the 2 x 20 Kw motors. ( 85 % efficiency for the motors and controllers)
The total cost for the complete battery system , BMS for both service and propulsion is € 100.000,00 , the cost for the complete propulsion/ regenerating system another € 30.000 excluding generatos, this boat will be used continuasly ( year around ) in the Pacific southsea where the owner will do surgical work on board to help people inmmedical need that lack this type of help.

 

[philSweet]

Do you know if the boat is also fitted with a power manager for house load management. Mastervolt also makes those and this would seem to be a suitable platform. Basically, I think we all would be very interested in anything you could tell us about the architecture/system integration of the vessel's electric system.

 

[fastcat435]

power management

Hallo Phil , yes we have power management on board , this starts and stops a generator when needed but also transfers ( automatic ) energy from the house batteries to the propulsion batteries or the other way around ( not automatic )
The propulsion runs of 2 x 6 mastervolt Lithium ion batteries in series to create the needed 150 volts plus, house voltage is 26.5 volts 1000 ah available.
Both the solar and the wind charge in to the house batteries and once these reach 28.2 volts a relay switches on to charge from the house to the propulsion batteries until these are full. to create 230 v ac we use dual Victron inverter chargers and they are combined with the AC generator or shore power .
there are 2 DC generators on board for extended cruising under motor power if no wind is available and one AC generator.
Each of these units can supply power to all boat systems via inverters or converters.

 

[lucdekeyser]

curved boards

From the pictures I have the impression that the pivot attachment of the curved boards stick out from the hull without much fairing. What is the reasoning behind this?
How much does the boat weigh as demonstrated?
Is it an optical illusion that the prop+arm looks much lighter on the 605 than on the 445?
Is the mini-OR also equipped with anesthesia gas tanks?

 

[fastcat435]

Good morning Luc, the hydraylic actuator is 80 cm from the water surface and is slightly build in to the hull, it is made from a alloy/titanium combination ant totally seawater corrosion proof and anodized. The prop is larger and has a larger pitch 17 X 10 instead of 16 x 8, the basalt fiber wing has the same dimension but the layup is doubled for more strenght, so far we have regenerated up to a sailed speed of 14 knots and all is fine ( 14 Kw of regenenerating power.
The mini OR will be fully equipped including autoclave, surgical 4 way bed etc etc.
Greetings Gideon

 

[fastcat435]

I forgot to answer the question on the weight and the fairing
She weights 17000 kilo ready to sail with water , diesel , RIB etc all on board .
the hulls are flaired in to the swing boards and the gear covers are completely flaired like with the swing keels in racers

 

[brian eiland]

When I looked at this first photo I wasn't sure what i was looking at....some sort of bow planing boards...ha..ha. This shot makes them look very far forward. In fact I'm guessing they are?

But it looks like you did a neat faring job for 'external boards'.

Now how about the water integrity of the hull should one be struck and damaged?

There must be a fairly long and/or substantial arm inside to activate these boards?

 

[fastcat435]

Hallo Brian,

they are located at the usual location about 4 ft from the mast location to the rear
The swing keels have a break off point build in but they can take a huge load .
If overpowered sideways a overpressure valve makes them move inward
We have used Helical actuators and gears ( 2 for each side that work in tandem )
Each can move 25000 Nm and the standstill torq is 100000 Nm
Each gear and shaft is located in a separate watertight compartment with bilge alarms and pumps. For sailing downwind they can be used at an angle of 90 degrees ( horizontal ) for additional lift , more or less like hydrofoils .

 

[lucdekeyser]

Thank you Gideon for all the additional information.
Is the cat at 17 Kkg in the video, because the waterline is about one ribbon equivalent from the black one or is it just light for the sea trials? If so it would be interesting to learn the performance numbers for its intended weight.
From the figures you gave I estimate the clearance with the bridgedeck to be about 1 m then?
There is a good case to be made for your swing keels. OTOH I do not feel comfortable (yet) about some consequences. I suppose there is too little perturbance in the flow between the hulls to increase the interhull interference.
But I do not want to high-jack a thread in the hybrid subforum.
Thanks again. Luc