need more experienced advice

Discussion in 'Boat Design' started by jbehr, Sep 20, 2010.

  1. jbehr
    Joined: Sep 2010
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    Location: Florida

    jbehr Junior Member

    alright lets see

    first the point of the greenhouse would be a sustainable source of food even if i were to not return to land

    second the solar power would be for energy generation in case i chose not to go to land also

    but i had a small idea and im not sure how it would work but here it is anyways as crazy as it may be to some:
    what if there were some type of slit at the bottom of the boat that allowed water to pass through(if it were a monohull) that would turn a hydro-electric generator helping to increase my allowed electrical capacity

    and also im not entirely sure why it takes 170 ft to house a 30 ft greenhouse was that simply for the purpose of the PV cells needed to power it? and on top of that natural light wouldve been used in the greenhouse so the only thing electrically needed to be increased due to the green house to the best of my knowledge would be the increased use of the fresh water maker

    also if i eliminated the electric propulsion to help free up the electrical input needed to feed it and instead chose to just use sails with no backup motor would this help it to become much more feasible?
     
  2. WestVanHan
    Joined: Aug 2009
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    Location: Vancouver

    WestVanHan Not a Senior Member

    If you are sailing you can generate enough power to fulfill your needs...but you won't get very far using it for propulsion..

    This is for small boat with 15 hp...you'd need much more....

    Get post 37 burnt into your brain:
    http://www.boatdesign.net/forums/hybrid/actual-hybrid-application-34504-3.html



    I don't like Roberts,but look at his largest sailboat plans.....imagine converting the aft cabin to a green house of maybe 120 sq ft:

    http://www.bruceroberts.com/public/HTML/V765.htm

    Will that small an area do?
     
  3. jbehr
    Joined: Sep 2010
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    Location: Florida

    jbehr Junior Member

    ok well with all the new input(thanks everyone) im going to restate my design purpose

    1) propelled by sails only
    2.) solar/wind/hydro electrically powered appliances
    3.) greenhouse

    as for my question about why a 30 ft greenhouse would need a 170 ft boat for its housing please elaborate further.
    was it the weight of the greenhouse?
    was it the PV's required?
    or another reason entirely?
     
  4. WestVanHan
    Joined: Aug 2009
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    Location: Vancouver

    WestVanHan Not a Senior Member

    If you won't say how many square feet you need,no one can give you an idea or waste any more time.
     
  5. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    A greenhouse at sea is impractical. The salt air alone will make this all but imposable. Don't believe me? Go down to the beach and put a tomato plant just above the high tide line and see how long it takes to die. If it survives a week, you'll be lucky.

    As I said, you need to do some research or hire a designer to do the research, as your comprehension of the issues is weak at best.

    This isn't a new set of variables, but it is one with a fair bit of problem solving to over come. You can over come them or at least gather enough knowledge, to help over come them or as I mentioned, hire this task out. Considering the vast amount of information and engineering disciplines you'll need, to come close to doing this yourself, I'd strongly recommend you hire a designer. Naturally, this cost money, then again welcome to the wonderful world of custom yacht design. There's absolutely nothing inexpensive about having a custom yacht designed for you. Particularly if the yacht is way out in left field in regard to it's systems and accommodation.
     
  6. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Jbehr, you are approaching the problem from the wrong end. Where does a 30 ft (what, square feet? or 30 ft by 30 ft?) number come from?
    The correct approach would be something like this: you want a greenhouse and you want 4 peraons on board. The question now is: what is the minimum size of a greenhouse which could produce enough vegetables for 4 persons? Once you get that data, you will have a starting point from which you will be able to examine the feasibility of the idea of putting such a greenhouse on a boat. Without that initial data, all the numbers and boat dimensions will be just useless guessworks and conjectures.
    Cheers
     
    1 person likes this.
  7. jbehr
    Joined: Sep 2010
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    Location: Florida

    jbehr Junior Member

    ok so ive come up with a rough figure of the amount of space i would need for the crop-growing area which will be 650-800 sq ft

    and im comfortable living in a 36-46 ft boat

    EDIT:im not saying the total size of the boat should be 36-46 ft im saying thats my comfortable living area :)
     
  8. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    So 65'-80' by 10 feet...so assuming a pointy front end,a very long boat.

    Sounds like you need a huge catamaran,for $4-5 million -a lot of money to grow veggies.

    WVH over and out
     
  9. jbehr
    Joined: Sep 2010
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    Location: Florida

    jbehr Junior Member

    hmmmm looks like i need to find an alternative to the greenhouse idea....im assuming since no one posted on the power neccessary after i eliminated the propulsion system from the equation that it must be possible to power what i was trying to require so now at least im down to managing my space.....
    lets see i could reduce the space needed by layering the grow beds i could feasible do this to a reduction of about 66% or so

    so 1/3 of 900=300

    so lets go with that then using the rough calcualtions posted above it should be in the general range of
    Beam=10-15
    Length=20-30

    so that looking alot better so letes see add the rough 40 ft length for living quarters
    and im looking at 60-70 ft sailboat
    that seems a lot more reasonable i mean at most 80ft or so
    any other objections to this?

    and as far as power is concerned having eliminated the propulsion system down to just sails is it indeed feasible? what kind of sails in your opinion would allow for maximum PV exposure while not diminshing the speed of the boat too greatly
    im sure ill be told that it depends on how fast i want to go so lets just say the exact average speed of a regular cruiser which is around what maybe 6-7 knots or so

    EDIT:also in reference to the electrical implications required with the added effect of layering the vegetation(meaning the suns rays wont be as great on the lower levels) is that i will have to now also install lights as a suppliment to the sun
     
  10. jbehr
    Joined: Sep 2010
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    Location: Florida

    jbehr Junior Member

    Summary:ROUGH ESTIMATES
    Length=70ft
    Beam=12.5ft
    Ventilation system for roughly 24 ft of the boat
    Light system(most likely LED) for the same
    Fresh water maker for the use of plants and a maximum of 4 people
    walk-in high humidity cold storage unit
    stove
    normal navigational and safety equipment

    im sure im missing alot but keep in mind these are completely rough estimates
    and again thanks everyone so far for expanding and helping refine my idea and please continue to do so if you feel so inclined your opinions are always welcome i just apprecaite the input

    so does this seem like a more reasonable boat? any problems with the current design idea?
     
  11. apex1

    apex1 Guest

    Unfortunately not.

    You cannot just calculate 40ft for you and 30ft for the plants and guess that 70ft will be the result. Such a greenhouse would add so massively to weight, that you come out far above your estimation. (maybe a bit below 170ft though)

    LED light does not emit UV, you cannot use it for plant growing (which would be a mad idea anyway).

    The autonomy you have in mind is not possible, sorry.

    Look for a NA to make a proper Statement of Requirements, this way does bring you any further.

    Regards
    Richard
     
  12. mydauphin
    Joined: Apr 2007
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    mydauphin Senior Member

    Perhaps easiest would be a barge that you tow behind. However, besides the problems of building a greenhouse boat, the big problem is what PAR mentioned, nothing will grow, it will all die!!!. The temperatures are too extreme and the salt in the air will kill everything. So you will need a complete temperature, humidity, controlled environment. So lets attack this from a gardening problem, how much land do you need to supply food on a continuous basis for 4 people. An acre!!!. Remember plants give croups only a few times a year, but they take months to grow into something you can eat. Chickens can be added fairly easily so you have eggs and eat a new chicken every six months. A floating farm for four will probably need 4 acres. Oh, you need to produce fresh water, have soil, worms, fertilizer, pollinating insects, etc... I think a used aircraft carrier might work especially a nuclear power one.
     
  13. mydauphin
    Joined: Apr 2007
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    Location: Florida

    mydauphin Senior Member

    Learn to fish, buy a sailboat, and make your own beer....
     
  14. jbehr
    Joined: Sep 2010
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    Location: Florida

    jbehr Junior Member

    how are you calculating the weight requirement for the greenhouse? as of the current design in mind greenhouse probably doesnt describe adequately how the system will work as i dont plan on having any glass.

    is this all soil weight to you or another part of this im not quite seeing
    im sorry but im still not understanding why you say the weight is so extreme
    also i realized my err about the LED lights and have devised a proper system to instead reflect light so no extra electrical output needed

    also the reason i havent brought this idea to an NA is because the idea is so rapidly evolving that i would need to repeatedly talk to him over the course of a few hours with nearly entirely different perspectives(albeit with the same goals though)
     

  15. jbehr
    Joined: Sep 2010
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    Location: Florida

    jbehr Junior Member

    also im no longer thinking about size requirements for the greenhouse i need 300 sq ft
     
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