A folding travel trailer on top of a pontoon boat~

Discussion in 'Boat Design' started by RonKMiller, Sep 1, 2010.

  1. Stumble
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    Stumble Senior Member

    Ron looks pretty ingenious to me. Though a couple of points.

    1) I would think about basket style wheel straps. They are much more secure than just over the top types. http://www.google.com/products/cata...=X&ei=7kgwT7W5LIPq2QWGuczxDg&ved=0CMQBEPMCMAw
    2) I would repurpose what you have to put in crossing straps at the four corners. This is how we strapped down trucks crossing the Atlantic, and goes a long way in making sure the cars don't move around when rocking.
     
  2. RonKMiller
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    RonKMiller Junior Member

    Excellent thoughts, thanks!

    The straps are kind of interesting since they come with 3 thick rubber pads that curve up and around the tire. They are sewn into the straps but can slide as you tighten to maintain their positions instead of creeping around the tire as you cinch. They are located at 10:00, 12:00 and 2:00. They have several "nibs" along the center that locate them in the middle tread so they can't slide off. Obviously if your tread is worn they wouldn't work as well - but I've probably got 90% tread left on the tires. The clamping force you can generate with those ratchets is pretty impressive - they've got much longer and wider handles than the typical Wal Mart types so you can generate a LOT of leverage. When I'm done cranking you can actually see the threads in the straps starting to stretch. Since the working load is 12,000 lbs. EACH I have to assume the breaking strength is double that. I'm OK securing a 2,000 lb. trailer with a safety factor of 12. ;)

    The four tie down points makes sense - I've got a tripod now - but ONLY when towing over the road: the 2 wheels and the hitch post which is held in place with a pretty stout pin - similar to what you would use to mount a hitch in a receiver, but not nearly as strong. There's an U shaped aluminum channel up front on top of the deck which spans two stringers and distributes the hitch load directly over the center pontoon. (about 250 lbs.)

    When I'm towing on the road I WANT the Chalet BODY to float on the tritoon deck and be on the springs to absorb shock instead of tied down tight. Right before heading down the ramp four screw driven corner jacks welded on the Chalet are deployed with my trusty 18 volt drill on high speed, it takes about 15 seconds each. They help stabilize the trailer body so it doesn't rock when you walk around inside the trailer, but also provide a wider "stance" and improve weight distribution underway. On water I've got SEVEN points contacting the deck.

    There's very little pressure on the jacks, but it really does make it rock solid since the weight on the leaf springs is lessened and partially re-distributed to the far corners of the trailer - and farther out on the deck - vs. resting solely on the axle and hitch. They're rated to lift 700 lbs., I probably put 200 lbs. or so on them max. No need to lift the trailer off the deck.
     

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  3. Wavewacker
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    Wavewacker Senior Member

    Well, maybe I have a little more building experience than initially admitted, not with boats, but structures.

    I'll let an engineer type explain it. You can not assume weight would be distributed like that at all. Each time your boat rocks it changes the center of gravity and the distribution of weight and forces working on those 4" aluminum flanges. They do not carry equal loads. Your trailer is not that well balanced either to assign weight such as that. Don't know what you fly, but you can feel the difference in a C-130 with a heavy load and it's much the same as banking when the center of gravity chnages and the weight is not all on the skids.

    All toon decks delaminate over time, regardless of the type of ply used. It's probably in good shape being newer, but just wait.

    Those flanges were not designed to carry a heavy load where the forces are so concentrated on a small area.

    I live within an hour drive of about 80% of the world production of pontoons are built. These aluminum tube boats originated in my backyard. I have had this discussion with several in the industry at different times and the company engineers will tell you the same thing, they are not designed originally to carry such weights. They can be modified!

    The fact that you have a tri is irrelevant to these issues, it's not an issue of boyancy, but structural integrety. The flanges of your center tube are welded to the beams and while it will add rigidity to the beam in the water, it does nothing for the compression on the deck.

    I have seen a faily new pontoon sitting on the hard on the side of a hill with its starboard side on the high side of the hill, it sat there for a few days, not even a week. When the guy came to pick it up, the weight of the boat at that angle had caused the flanges to tear from the low side tubes and it collapsed under its own weight.

    Production pontoon boats are not designed to put cars, campers or other heavy items on them.

    In your case, you also have used those plates under the wheels which really helps in the issue mentioned, your area being compressed by the weight looks to be four or five times greater than if it were simply sitting on the plywood.

    Your lashing/tie down looks good too, to an Ozarkian Engineer who has only had about 50 years around these boats.

    I point this out to try to keep some fool from putting a trailer on a stock pontoon or tri and getting into some chop on a large lake, without taking precautions as you have with those plates. It's not the deck failing so much (but is a real concern with a 1/2" deck) as it is the flanges failing, 24" on center is not sufficient when the welds are only 4" on both sides of that flange (which are made in two pieces ][ )

    The flanges should be reinforced in my opinion (and as I was told) by adding angle stock along the welds of the flange and tubes across a longer surface, like running angle the length of the tube over the flanges welding the flange tothe stock and the stock to the tubes. Wish I could draw a picture on here!

    I think you have a nice rig there, and it does not appear to be an old boat, I just suggest you keep a close eye on the condition of the commections and deck and stay out of rough waters.
     
  4. RonKMiller
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    RonKMiller Junior Member

    So, you are sitting there, typing away and proclaiming this unsafe? Yet all we have is your self proclaimed "opinion" to go on. Give me a break... the proof is in the pudding. I also happen to have an Airframe and Powerplant rating - I'm not some naive hillbilly pasting together a boat with duct tape and Elmer's glue. :rolleyes: This boat fits into one and only one category:

    EXPERIMENTAL. Get it?

    I appreciate your views, but I have NOT exceded the maximum allowed gross weight as established by the manufacturer. Indeed the original sticker is still on the boat. The Coast Guard inspector and I had a long discussion about this - and he made me pretty much prove that the original structure was more than up to the task. BTW, he is a former Air Traffic Controller and a major PITA - but that's what they were PAID to do.

    You have to assume that 15 people - yup, that's what the Party Hut I salvaged was certified for initially - could all stand on one point on the deck without causing a catastrophic failure of the substructure. That's 3,000 lbs., focused on one small area...

    I think you feel that pontoons are very fragile, but the combination of an engineered lattice and structural skin (the deck) create a much stronger structure than you could ever imagine. Adding reinforcements would be a GOOD idea, but after having slammed into 3 foot waves created by a tour boat - and not breaking in half - it's not something I an going to lose any sleep over. I will inspect all those welds just to see if they are still intact, but quite frankly they are VERY stout, and believe it or not the original manufacturer (Suntracker) guarantees their welds FOREVER.

    Why, that's exactly how air frames are made. :) (and I HAVE made a few flying machines over the years) ;)

    This boat is and never will be adequate for any kind of rough water, but it handled one foot chop and whitecaps (with wind gusting to about 30 mph) quite well. It handled Lake Powell during fair weather, but I would NEVER want to be out in a thunderstorm in it. That's the beauty of it though, just beach, pop the top, turn up the stereo and chill for a while. Why, you can even have some strawberry sorbet or a dark chocolate Haggen Daz bar while you wait out the storm. :p

    Like Dirty Harry said: "A man's GOT to know his limitations". :D:D I draw mine at ice cream.

    http://www.youtube.com/watch?v=CG2cux_6Rcw
     
  5. Squidly-Diddly
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    Squidly-Diddly Senior Member

    200lbs for goodies/gear sounds lite, but click my handle for my gallery

    for my idea of generic modular pontoon boat system.

    One of the things I'd propose it for is 'land lubber' applications like RV or office or even workshop, medical etc trailers or vehicles.

    Yeah, I'd want to be able to just drive on a full size van ambulance rather than try to create a ambulance-boat.

    At a 40' size format, with beam to match, I'm thinking a 30-40 RV trailer along with a 40' CONEX box or office trailer, or 18 wheeler trailer.

    Tarp for shade between the two.
     
  6. viking north
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    viking north VINLAND

    To hide that trailer on a boat look-- design and install a skirt to surround the lower section between the trailer and the floor of the boat. It will make all the difference in the world and one would be hard pressed to realize it wasn't a typical pontoon house boat setup.
     
  7. RonKMiller
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    RonKMiller Junior Member

    Um, dood... whatever you're smokin' - I WANT SOME! :D:D:D:D:D
     
  8. RonKMiller
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    RonKMiller Junior Member


    Ummm, OK. I should have thought of that. :rolleyes:

    I'll get right on it:
     

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  9. viking north
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    viking north VINLAND

    That wasn't shown in your photograph on post #13 and I'm sorry to have offended your intelligence. I will make note not to do it again by a safety feature we have on this forum known as "Ignore"-- Arrogance usually promps that button to be pushed.
    P.S. Sorry CT missed your same suggestion--Geo.
     
  10. RonKMiller
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    RonKMiller Junior Member



    If you're too lazy to explore the 115 pictures I provided after a year's worth of work - and starting shooting from the hip... then you do indeed deserve one of these: :rolleyes: and one of these: :p

    You could have started out on a positive note and said something like: "Hey, I like your boat", but instead choose to offer brilliant ideas on how to improve it... that, my friend is the definition of arrogance. Whatever you do, don't mistake the difference between arrogance and confidence - they are light years apart and I know the difference.

    Alas, I digress:

    There was a lot of work and thought that went into the sides. They are an important part of the design:

    1. They fold down and provide a "mouse walk" for access to the trailer and stern seating/motor, etc. There are finely crushed walnut shells embedded in the top of layer of elastomeric coating that covers the Meranti plywood. There are also grab railings bolted to the sides of the trailer body for safety.

    2. They provide containment for loose cargo stowed under the trailer.

    3. They provide spray protection to keep the deck dry as well as provide some aesthetic continuity to the design. It certainly isn't the most attractive vessel out there, but considering it was literally cobbled together from bits and pieces it turned out quite well. Everyone that has seen it wants to know who the "manufacturer" is.

    4. They provided a great place to mount the BMW badges - from the "manufacturer" - of course! :D
     

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  11. Wavewacker
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    Wavewacker Senior Member

    LOL, check wheels down, report outer marker! Check wheels locked! Go around, go around, go around, Wheels Up! Execute missed approach, climb and maintain 2000! Report 2000, hold southbound of your assumptions. :D
     
  12. RonKMiller
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    RonKMiller Junior Member

  13. Petros
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    Petros Senior Member

    I just found this thread, Great project! Excellent execution of a very old idea.

    This subject comes up every year on this forum, this is the best one executed so far. looks like a first class adaptation, congratulations on your hard work and determination.

    I have long thought that an all wood folk-boat kind of look would make a keen "custom" little travel trailer, that just coincidentally would fit into a sailboat hull. So you use the same accommodations when land camping or sailing.

    I suspect however it would be more work (and weight) than just building them separately. Nor do I have the time or resources to take on such a whimsical project.
     
  14. RonKMiller
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    RonKMiller Junior Member

    Thanks for the nice comments. The time thing was a MAJOR component since I had to custom fit - and re-fit - everything... Many days it was one step forward and two steps back. I didn't keep track, but I would not be surprised if I had 1,000 hours into it. That's roughly equivalent to working on it full time for 6 months. :eek:
     

  15. RonKMiller
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    RonKMiller Junior Member

    I just received my 2012 Coast Guard safety inspection sticker today - but got reamed out pretty good for having my registration numbers/letters on back ***-wards and not having the proper spacing.

    DOH! :eek:

    Well, what do you expect from a newbie?? :D At least I got the 3" height correct.

    Guess I'll need to buy some new vinyl letters. (But I bet I can re-attach them with some spray glue...) ;)
     

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