60 ft catamaran for solar venture

Discussion in 'Fiberglass and Composite Boat Building' started by ian.armstrong, Aug 16, 2013.

  1. ian.armstrong
    Joined: Aug 2013
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    Location: Maui, Hawaii

    ian.armstrong New Member

    I am planning on constructing a 60ft catamaran for a solar venture. Long story short instead of putting solar panels on land, we sail out a bit and deploy them in the ocean. Each panel floats with battery, and we retrieve the battery when charged and install it in a house.

    Our current boat lease is up in Maui. I am now looking to construct a boat specifically for this purpose, and am choosing a 60ft catamaran. I would like to do the following:

    3 layers of C-flex 65 (link here)
    a 10mm layer of foam (not sure what type, I would like suggestions)
    3 more layers of C-flex 65.

    I intend on using a load bearing hull design that is 60ft long, and 13 feet wide for each of the hulls. I plan on creating the foam core first, then adding the c-flex. The hulls will be constructed upside down, and rotated when constructed. Both will have a metal pipe frame for additional support every 5ft, and the hulls will be joined in the harbor using the pipes. The rest of the boat construction will occur in water after the main deck has been attached.

    Im incredibly new to this. As in, first timer. I have two months for the warehouse, as well as the transport to move the 60ft hulls to the ramp for deployment. My main questions are:

    1) C-flex is incredibly expensive. Using a foam core I would like to utilize fiberglass, but am not sure what types would work. Any suggestions?
    2) The foam core: im concerned about the bonding of the foam and the fiberglass. Should I put the foam core in segments and then bond with fiberglass?
    3) Hull thickness: This will be a load-bearing hull. I would eventually like the hull to be able to support two stories, almost like a house boat. I anticipate the height of the hull being 7ft. How thick should I make the hull?

    As I said, I am new to this. Shoot suggestions my way. Im interested to hear thoughts and im even more interested in suggestions and potential criticisms.


  2. El_Guero

    El_Guero Previous Member


    You need a professional designer, naval architect. There are several on the forum.

    There are designs out there for ready made Catamarans, but you want to be able to modify it in the future .... She will already be heavy. Adding 'up' will only make her heavier.

    A professional can probably take one of their previous designs and modify it for you fairly quickly.


    PS: somewhere between 15' and 30 foot is huge for a first time build. 60' is really huge for a first time build.
  3. El_Guero

    El_Guero Previous Member

    Before I forget,

    What they will want to know are things you are letting distract you.

    How much weight do you need to carry at one time? What is your cargo weight?

    What size auxiliary engine would you use? I assume green technology, you will use sail as your primary.

    How many crew, passengers? What length of time will your cruises be? And I would assume this is also a live aboard?

    From there, they can give you much better ideas about your overall weight of your vessel.

    What is your time frame? And do you have a budget cap? 60' is not usually cheap. That is why most people buy in the 40' range.

    Also, 60' is often a dedicated 2 person crew. There are labor saving devices, but you can only save so much.

    And they can guide you in choosing your laminate material (hull material).

    I do not remember names very well, but Richard Woods, Par, and then I go blank again. But, they post often and design craft.
  4. ian.armstrong
    Joined: Aug 2013
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    Location: Maui, Hawaii

    ian.armstrong New Member

    Naval Arc.

    The vessel will have live aboard capabilities. I have spoken with a naval architect about this, but the concept that he gave me was a lot less than what I was expecting.

    He suggested a hull that was 1 inch thick. I cannot possibly imagine that a catamaran has a hull that is only one inch thick. I asked about foam, and he suggested that I make it .5 fiberglass, .25 foam, and then .25 fiberglass again. I still do not see how that is thick enough for a 60ft hull.

    When I first designed the concept, I suggested that metal rods be used to add a stronger superstructure to the hull shapes. He actually told me that my support structure was "overkill". Am I wrong in thinking that it would be better to have a good support structure?

    The vessel will have electric engines. Electricity is my specialty, and we have enough solar panels to power the entire harbor if we needed. I plan on integrating panels heavily in this vessel. A total of four wind turbines will also be used, two starboard and two port. All wind turbines are easily lowered and easily raised. Ive done electrical for boats before, just not structural.
  5. tomas
    Joined: Nov 2012
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    Location: California

    tomas Senior Member

    As an inexperienced boat-builder myself, but experienced in other types of fabrication, that time-frame for just the hulls and basic structure could work with an experienced group of workers, but if it's just you with a steep learning curve and a little help, it's likely not realistic.
  6. El_Guero

    El_Guero Previous Member


    I agree with your NA.

    You are going for overkill.

    What is the hull thicknesses on the boat you are leasing?

    A one inch hull, backed by bulkheads, stringers, and the keelson is a very strong tube.

    Except for wind resistance, aircraft would still be flying with skin on frame .... imagine your nylon pants made into the skin for your boat. It does not take much, when it is all in the right places, and right velocity.

    You can add in some overkill if that lets you sleep at night. BUT, do not add too much, you must LIVE with every added ton.

    Your hulls are too wide for reasonable speed.

    The best shape for the bottom of the hulls are two half circles .... And I think marine plywood is a better choice for cost, ease of use, and time to put together.
  7. El_Guero

    El_Guero Previous Member

    Here is a commercial design: http://www.sunreef-yachts.com/model-description,Single-Deck-Catamaran,49,sunreef-60-loft.html

    33 ton weight. With two hulls 8 foot beam each (16 foot together) you would draft about half what they are drafting.

    Plenty of room and reason to go narrower ....

    If you need the space, consider going longer and narrow, yes the expense goes up rapidly. But, you will still be able to sail in low wind conditions. And your boat won't handle like a 'pig in the water.'
  8. ian.armstrong
    Joined: Aug 2013
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    ian.armstrong New Member

    Low speed with electric outboard engines

    Sail will not be the primary method of transport for this vessel, it will be electric outboard engines. I don't need the vessel to be able to move very fast. I would like it to be able to carry a lot of weight. Do you think that instead of using the hull width of 13ft I should cut it down to 8ft?
  9. El_Guero

    El_Guero Previous Member

    26 foot beam for a Catamaran at 60' length will give you a lot of parasitic drag.

    There is a bow wave that meets between the hulls, and they will really make that boat drive like a pig in the water - IMHO. So yes, an 8 foot beam for each hull will be better. Asymmetric hulls like Richard Woods uses would help a little, but are not a total fix. Increased resistance in the hulls themselves.

    How much weight do you need to carry? Multiply by 150% to get maximum operating weight.
  10. El_Guero

    El_Guero Previous Member

    3.41*16*50*60 = 82 tons
    pi*(r)2*(shortened hull length)*(water weight per cubic foot) R squared is used, because you have half of a circle at the bottom of each hull. This value is just the bottom 4 feet of your rounded hull.

    All weights are a low.
  11. Alik
    Joined: Jul 2003
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    Alik Senior Member

    Sorry to say, but most of unrealistic projects from 'boat dreamers' include this so-called 'electrical propulsion'. Actually, this is primary feature of such projects. Not an option for average ocean going boat, at this stage.
  12. El_Guero

    El_Guero Previous Member

    Yes, but it would be a great marketing scheme when selling the very un'green' battery power to 'green' consumers.

  13. groper
    Joined: Jun 2011
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    Location: australia

    groper Senior Member


    "Planet solar" has already proven the concept can be workable... just not cost effective.

    A bunch of well informed guesses here, but your idea has several problems.

    Firstly, its more efficient to carry everything on the main vessel, not drag around a bunch of floating power cells. If this idea had merit, you would see smaller cargo ships towing a string of barges around with them to increase payload. The problems arent just efficiency either, also safety and practicality.

    Secondly, you admit having no structural design background - so why dismiss the methods and reasoning of people qualified and experienced in naval design, as if you are to know better? The content of your original post shows that you clearly have no idea what your doing, and with respect to such a large and ambitious project, you would be absolutely out of your mind to attempt it without the support of specialized professionals - right down to extreme efficiency propellers, finite element analysis, tank testing, the whole shooting gallery. Why? Because what you are proposing sounds easy and simple in your mind, but the reality is that its an extremely difficult set of problems to solve - which is why noone has done much of it yet, and the main reason noone is doing it, is because its still too expensive to implement and thus a poor economic return over the life of the vessel compared to other technologies - the main one being standard yacht sails with fossil fuel engines when the wind doesnt blow.... there are reasons for the status quo, its not simply that noone has thought of it yet, many thousands of people HAVE already thought of it and ARE actively working on it....
  14. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    Well, I can't figure out where that makes any sense.

    C-Flex isn't supposed to be used like that. C-Flex is self supporting and used to easily give a shape that will support laminations of much cheaper conventional fiberglass. You only need 1 layer of C-Flex, once that has been covered in resin and solidified, you switch to conventional materials.

  15. Alik
    Joined: Jul 2003
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    Alik Senior Member

    This is exception that proves the general rule. Electrical propulsion means complications with weight carrying capacity, service of equipment, lack of flexibility in restricted areas of navigation, etc. Can be solved on one-off demo project with extensive budget, but not on amateur project.

    Lagoon - do they still produce cats with electrical propulsion??
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