Trailerable Multihulls

Discussion in 'Multihulls' started by JCD, Mar 4, 2008.

  1. JCD
    Joined: Jul 2006
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    Location: Coney

    JCD Follow the Bubbles!

    Whoops...don't know what happened to the picture.

    Here it is again.

    J:cool:
     

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  2. JCD
    Joined: Jul 2006
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    JCD Follow the Bubbles!

    Wow...quiet in here.

    Question on the beams. Should I make the core in ply or foam for sandwich? I'm leaning towards ply?

    J:cool:
     
  3. Richard Atkin
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    Location: Wellington, New Zealand

    Richard Atkin atn_atkin@hotmail.com

    Hi there J :)
    It sounds to me like you have been inspired by my cat design :D :D :D

    What is the best small cruising cat? My one ofcourse....but if you want to make one with more bridgedeck clearance, a shower with standing headroom, and solid bridgedeck cabin....then it would be very different to mine and I will be watching eagerly :)

    I liked the comments from Richard Woods. He brings attention to the 'personality' factor of sailing. One person is happy with one thing....while another is happy with something else.

    There are some things that apply to most people, I believe.

    Here's a few:

    Most people will enjoy the cabin for a while...but always end up migrating to the open deck when the weather permits. Here you can feel the ocean more and really enjoy the sailing atmosphere. Open deck is important.

    Most people are not rich. Trailerability is important.

    Most people don't truely enjoy the burden of ongoing maintenance.

    Most people don't sail very well, and don't sail thousands of miles from land.

    Most places in the world are not very windy, most of the time. Light air performance is important....and is often a problem with cruising catamarans.

    Most people are discouraged by the THOUGHT of being cold, and therefore place a lot of importance on cabins. When they are forced to wear very warm, comfortable clothing (forced by the captain), most people become suddenly delighted by the lively sailing experience....that is....sailing out on the open deck, in full view of an exciting ocean, and the 'bad' weather becomes fun. Most people don't believe this until they actually experience it. This is because they are often not quite comfortable enough....and this ALWAYS destroys the experience. Even a small amount of discomfort can ruin everything.


    Hence....the large amount of attention to TRUE comfort on my own cat design, as opposed to IMAGINED comfort. Warmth, back support (and side support by 'horse shoe' cushions), and a large tent will cover the entire deck when the boat is anchored/moored.

    Just my thoughts, and a little bragging, from your friend Richard :D
     
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  4. Richard Atkin
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    Location: Wellington, New Zealand

    Richard Atkin atn_atkin@hotmail.com

    Richard Woods
    I can't stress this issue enough. So I will stress it some more.

    How often do you here this: Oooooh....no more camping for me.....maybe I'm just getting old.

    Why does the old guy not like it anymore?

    Is it because he got too cold one night? His bones ached when he carried the pale of water? He stepped in some poison ivy and his immune system couldn't cope?

    No way. He just got bored. He got bored with all the little discomforts that were stopping him from relaxing and just soaking up the wilderness.

    People who don't camp often....hardly even feel the discomforts....because the whole experience is so stimulating.

    If you spend hours and hours on the ocean, the stimulation starts to fade, and so the mind becomes more reactive to all the little discomforts. It's human nature.

    So....being comfortable is not just about physical comfort, it's about stimulation. If a boat does not feel stimulating, then no amount of cabin space or deck space or hot water pressure or standing headroom or fully flushing toilet is going to cure the 'irritated' feeling.

    My idea of a great campng trip, is one that allows a wide range of fun things to do, all within the one holiday. If someone doesn't feel like doing anything, then they are welcome to sleep or read a book or do whatever the hell they like. But having many options available is the secret to a great holiday, in my opinion. This principle applies to any kind of holiday...whether its camping or sailing or both.
    You can't deny the human need for stimulation.
    You can't deny the need for rest and physical comfort.

    Eg.
    I always go camping where my friends and I can surf/body surf/waveski. (The girls can't surf but they still love it)

    I never go camping without a 6 inch thick mattress and pillow.

    Even old people like to go camping with me.


    So to conclude....a boat should allow you to do what you really want to do. It sounds simple...but I think so many people get it wrong.
    Never ever design a boat to be impressive. If people are impressed, it should be because they are happy.

    Lord Richard has spoken.
     
  5. JCD
    Joined: Jul 2006
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    JCD Follow the Bubbles!

    Ahoy there Richard...

    Not much here. Almost done with the traveling. I see you've been taking pictures and making Perry eeeemotional? Good.

    Hmmm...we'll let you keep believing that since although I didn't, I do like your design very much and might have borrowed some ideas permanently if I would have been designing the AtCAT knockoff.:D Actually...I'm attempting to do it because I have yet to find a trailerable catamaran design that starts off as an offshore design. Huge gap if you ask me.

    Because it is intended to be offshore, some modicum of comfort must exist and yes, that will include shower, bed, head, kitchen and hopefully some kind of protection from weather.

    Right now I'm trying to work out the design on the beams and I was going to use plywood...but the weight was incredible, so I have to try to design it with foam and glass...might be high density and carbon...not sure yet.

    Yes...and he knows because he doesn't pass up a moment to get on the water. Ahhh...soon, real soon...it will be me.

    True about the cabin and deck.

    I think that this is going to be one of those times when an open deck will be a must. I am thinking about trying to make a center cockpit in each ama with aft berth and the forward cabins for everything else. It will be a little tight, but if I can manage a two seater "protected" cockpit in every ama...I think it will be very nice.

    Most people are not rich and neither am I and I think that making a trailerable offshore cruiser will eliminate expenses by at least 80%. Also...imagine this...sail down the ICW to Florida and down to the islands. Swing West and visit the Eastern coast of South America. Transit the Panama canal and head to Hawaii for a while. Head North, visit the PNW and pull in to skinny water in Alaska where your trailer was delivered. Hitch up and drive through to Michigan will using the cat as your "sailhome", drop her in the Great Lakes and sail the NY canal system, down the Hudson and back home to Coney Island where the trailer is once again waiting. Hitch up and go home. Nice first cruise in a trailerable offshore catamaran.:D

    Very little maintenance and although most people don't sail thousands of miles offshore...some do it with vessels not designed as such. It will be very comforting to know that if you did want to do it...then at least the design is rated capable. Hopefully the skipper will be rated the same.

    Exactly. Foul weather gear is as essential to comfort and safety to crew in high lattitudes as swim wear in the lower lat's. Comfort is a definite mandate to this design because it is so small and hopefully capable of long passages.

    Do me a favor and walk the Green Lantern in your virtual program and let me know how it feels for comfort. Also, would you walk the trailerable if I put up a preliminary hull? Thanks

    J:cool:
     
  6. JCD
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    JCD Follow the Bubbles!

    Woah...check your pulse!

    All of the above is true. I'm a realist. A boat should allow you to do everything you want to do and in comfort while never fearing for safety in any manner or form. However, the purpose of many designs is to fill different needs...although some designs may fill many needs at once. If a design meets the needs of a crew, as different and odd as they may be, that is impressive.

    If the lines of the boat are nautical then that may be impressive also, but true impression comes when you have pushed the envelope unknowingly or are faced with a chaotic surrounding and she forgives you after you have made a mistake. That is impressive. Any vessel that is smart enough to take care of her skipper impresses the chit out of me. I have always leaned to these types of designs and try to come up with designs that do the same. The only way I try to impress is stimulate, comfort and safety. Everything else is anyone's pickle.

    I gotta figure out a name for my trailerable baby lantern. Any thoughts? Anybody? Here are a couple of pics after cleaning her up a bit.

    J:cool:
     

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  7. rayaldridge
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    rayaldridge Senior Member

    My first thought was to try to find out if any existing trailerable catamaran design came off the board designed to be offshore capable, in any category. As much as I looked, I didn't find any.


    Thomas Firth Jones' Brine Shrimp, a 23' catamaran that folds to highway legal width, was designed to cross oceans, with a crew of two.

    Ray
     
  8. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    Hi J
    I wish I could. My house architecture program is not compatible with your files. Everything must be redrawn in the program, as I did with my boat, and it's not good for multi-axis curves (there are ways to cheat but it takes ages).
    When you draw your designs in some kind of CAD software....I strongly recommend that you use software with a life-like walk through function. It makes a HUGE difference to the design process. I made many changes after using my walk through view.
     
  9. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    Do you have a boaty last name? :)
     
  10. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    Why not simple aluminium tubing for the beams? Light, strong, non-corrosive, cheaply manufactured, and the round tube is good for withstanding forces from every direction....that's why you see it in so many applications.
     
  11. JCD
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    JCD Follow the Bubbles!

    Hello Richard,

    Well...it's okay on the virtual reality.
    No...my last name is not boaty...just my designs.

    I'm not sure why tubes may or may not be a good or bad idea. My first thought is that I may not be able to figure out the "round" folding mechanism and the tube may have to be huge to handle the loads. I'm still in the early stage to really decide, but it looks like a foam/glass rectangular box beam may be the best way to go for weight and strength.

    I've been looking at the hinging first to see if it will be feasible. We'll see.

    Thanks
    J:cool:
     
  12. JCD
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    JCD Follow the Bubbles!

    Hello Ray...

    Thanks for the effort. I've been hoping that something would be pointed out. I looked up the design you pointed out and it is a very nice design. However, the designer states that it "could" cross oceans, but not that it is designed to do so. In fact, he likens the cruise in Baja as best suited for the design and denotes that an offshore crossing with two members would overload her.

    I ran her limited specifications numbers through my spreadsheet to give her the benefit of the doubt and she doesn't fit generally accepted results for offshore rating. I think that her displacement may be the determining detriment.

    Thanks again and if you do find something, let me know.

    J:cool:
     
  13. Petros
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    Petros Senior Member

    I have been following your thread for a few days and I have thought about a similar sailboat for the last year. I think it is great idea, a cruise capable sailboat that can be trailered would save a lot of ownership cost.

    My own thinking went like this: for recreational sailing and overnight trips owning a trailerable boat means it costs you little to nothing when you are not using it if you can store in out of the water in your backyard or driveway. With a fully equipped cabin than extended multi-day trips would be comfortable and more fun (and less expensive than most vacations), and it would be nice to have the capability to use for extended deep water trips, just in case you need an extended leave of absence. So then the question is what is the smallest practical deep water sail boat that would still be trailerable.

    A catamaran gets you both more deck space and less weight for the same size sail than a monohull. This is good for both sailing performance and trailering, as long as you can make a rugged, light and simple folding beam mechanism. I guessed that a 24 to 28 foot length is the best size, my design has a 12 ft beam, trailering with at about 8 ft. It appears you have determined about the same size.

    I considered a tube beam with a folding mechanism, a "truss" beam, and built-up wood beams. I gave up on the folding beam because there is no simple and light way to do this, it adds a lot of weight and cost, and increases the risk of structural failure. I think something far better would be telescoping or removable beam. It would only take removing a few large thru fasteners to allow the two hulls to be pushed together, simple reliable and much less costly. And though a little less convenient, it need not take any more time to set-up, it would be lighter and more reliable.

    What is your intention with the design? Produce finished boats, or sell plans? Or just build one for yourself?
     
  14. Meanz Beanz
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    Meanz Beanz Boom Doom Gloom Boom

    The Woods Sango/Wizard is the most practical solution to trailerabilty that I have seen.
     

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  15. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    Wow... I really like that sango wizard. The folding technique I mean.
     
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