51' Electric Sailing Catamaran

Discussion in 'Electric Propulsion' started by david@boatsmith, Apr 19, 2021.

  1. david@boatsmith
    Joined: Aug 2008
    Posts: 129
    Likes: 17, Points: 18, Legacy Rep: 75
    Location: Jupiter Fl USA

    david@boatsmith Senior Member

    Hi all, We are currently building a large sailing catamaran. She will have electric propulsion.
    The boat will cruise at 30,000 lbs. She has 42' lwl, 26' boa, 3'6" hull wlb,
    3'6" hull waterline beam, draft of 3.9". We have 4 Netgain hyper 9hv motors. These motors will run at a nominal 168v. There will be one inboard motor in each hull , belt driven with a 2:1 reduction, through an Aquadrive thrust bearing, and a 24" 3 blade feathering Max prop with an initial 20" pitch.
    For the propulsion batteries we are using 2 banks of 7 Tesla model s 24v battery modules in each hull. We are using 4 Orion 48 BMS units. The batteries will be in metal boxes to slow down a catastrophic battery failure with a 60 gpm seawater connection to flood the battery box. My owner has dubbed this pump switch the $100k switch.
    The boat will also get two Beta Marine 38 hp diesels. These will be coupled to the other two Netgain motors to function as 168v dc generators.
    House loads will be handled with a 24v house bank size as yet undecided. Our diesel shipped today from North Carolina. Our motors and propulsion batteries are her now.
    The hulls are a 60* vee hull. This is a ******* child Wharram design if you will. But with all the bells and whistles that many people want these days. Refrigeration, air conditioning, two electric heads, elecrtic galley appliances, electric winches and so on.
    I will post some photos of the project soon.
    David
     
    fallguy and Dejay like this.
  2. philSweet
    Joined: May 2008
    Posts: 2,410
    Likes: 237, Points: 63, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    It's hard to do at 30,000 pounds with all the bells and whistles. The last 50' cat I was on that had all the bells and whistles was 50,000 pounds (no water, minimal fuel). It was advertised at 22,000 pounds by the factory. It had twin 75 Yanmar turbo diesels, a 20 kW genset, a water maker, washer, dryer, and about 9 ac compressors. I think it had a total of about 20 SLABs altogether. It had 250 gals of diesel tankage, 300 of water. It will be interesting to compare the total drive train + genset weight and footprint of the two systems.
     
    fallguy and bajansailor like this.
  3. Mr Efficiency
    Joined: Oct 2010
    Posts: 9,639
    Likes: 838, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    I'm intrigued at how you have 9 feet of overhang, are you counting bowsprits and swim platforms ?
     
  4. bajansailor
    Joined: Oct 2007
    Posts: 1,804
    Likes: 575, Points: 113, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    Yes please re any photos that you can post showing the construction of your new vessel - I am sure that most folk on here would be very interested in it.
    Do you have any drawings or even basic sketches that you could post as well?
    Who designed her?
    I would agree with Phil that 30,000 lbs sounds very optimistic for a loaded displacement for a cat of this size.
     
  5. david@boatsmith
    Joined: Aug 2008
    Posts: 129
    Likes: 17, Points: 18, Legacy Rep: 75
    Location: Jupiter Fl USA

    david@boatsmith Senior Member

    Ya'll can see some vids at Boatsmith on you-tube.This is an open bridge deck catamaran.
    )k, not all the bells and whistles. No laundry only 2 ac compressors. Low volume hulls.
    Tis design is an extrapolation of the 48'er we built a few years ago. Those hulls had a 6' depth and beam. The current vessel is 7' x 7'. We are setting up a test platform with two stacks of 7 modules driving one netgain belted to a second netgain in regen to charge a second stackof 7 modules. The folks at Green Shed Conversions are helping me program the motor controllers. our Beta diesels are being delivered tommorow.
     
  6. bajansailor
    Joined: Oct 2007
    Posts: 1,804
    Likes: 575, Points: 113, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    As David could not be bothered to provide a link, here is a link to the first (of three so far) videos that he has posted on his Youtube page showing the construction of the 51' cat - he notes that it is a 51' Tehini.

     
    fallguy and Dejay like this.
  7. Dejay
    Joined: Mar 2018
    Posts: 616
    Likes: 113, Points: 43
    Location: Europe

    Dejay Senior Newbie

    Looks like it's going to be a beautiful boat! And a very nice workshop in a gorgeous location as well :) Thanks for the video David!
     
  8. david@boatsmith
    Joined: Aug 2008
    Posts: 129
    Likes: 17, Points: 18, Legacy Rep: 75
    Location: Jupiter Fl USA

    david@boatsmith Senior Member

    good call lwl is 46'
     
  9. david@boatsmith
    Joined: Aug 2008
    Posts: 129
    Likes: 17, Points: 18, Legacy Rep: 75
    Location: Jupiter Fl USA

    david@boatsmith Senior Member

    here are some of the new toys.
     
    Dejay likes this.
  10. fallguy
    Joined: Dec 2016
    Posts: 4,278
    Likes: 736, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Very cool stuff David. Thanks for sharing.
     
  11. Dejay
    Joined: Mar 2018
    Posts: 616
    Likes: 113, Points: 43
    Location: Europe

    Dejay Senior Newbie

    Yeah thanks for the tour!
    Not sure if I got that right, you have 4 of the same motors, two for propulsion, 1 for regen, 1 for generator?
     

  12. david@boatsmith
    Joined: Aug 2008
    Posts: 129
    Likes: 17, Points: 18, Legacy Rep: 75
    Location: Jupiter Fl USA

    david@boatsmith Senior Member

    one motor in each hull for propulsion. one motor on each Beta in regen for generator. It is hard to find 168 vdc generators. The propulsion motors will also regen under sail. We are having Steve Clunn and team help us with this process
     
    Dejay likes this.
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.