My new "monstrosity" design....

Picture with descriptions coming soon...

 

OK, so basically this is my newest concept for a trailerable houseboat / cruising boat.

The main frame structure would be the "d" section, the "e" section is a thin framed lightweight room that slides down over "d" during transport and storage.
It would be comprised of 1" tubing mostly, and covered in "sun tuff" tinted plastic, so the whole room would be see through.

The framework under the body and "wings" would be hinged, and connected with bolts. During transport, the wings would fold against the wall, and the frames would un-bolt and collapse, and the pontoon would fold over on to the roof.
(See "b" & "c" for collapsing frame illustration. )

The frame under the body ("f") would also collapse, as also illustrated in "b" and "c".

The entire package, would measure about 8'6" x 8' folded up (length to be decided), and unfolded, the top of the top roof would be about 16' high, and the pontoons would be about 24' from center to center.

The pontoons would be slightly longer than the body, and over the roof would hover over the tow vehicle while transporting. This will also add buoyancy to the front of the vessel, which is good because the engine will be in the front.

The very front of the bottom floor, will have the engines sitting in a "pod", which is sitting on 2 pins, and allow the assembly to rock back and forth, allowing the solid attached prop shaft to lift in or out of the water.

The bottom of the pod would sit just out of the water.
It could easily be retracted up into the body further for transport.
"a" is a drawing of roughly how the engine pod would sit.

"g" is a possible extra deck for the front, which would fold all up against the front wall during transport.

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So, with all this said, I am interested in hearing input on what materials might be ideal, and what you would change to make this better.

The aluminum pontoons, I'm thinking 36" from u-fab maybe?

The entire rest of it, I'll try to add up what it would weigh in steel, but if it's too heavy, I'm feeling maybe aluminum bolted, not welded?

 

Save yourself alot of torture and look for a set of plans -- I'm not saying this to be negative but my read from your post you are new at the boat building field and a set of plans will be a great teacher as well as a rewarding outcome---

 

You can't even buy a boat close to this, so where would I ever find plans?

 

Maybe there's a reason why you "can not find a boat close to this" Possibly it's not a pratical design both from an engineering and cost viewpoint. Not saying it can't be done but it would require the assistance of a professional in boat design and engineering. There is far more than meets the eye here in order to come up with a safe and pratical craft. You are looking at hundreds of hours of engineering work to develop a one off prototype. Far better to search for off the shelf plans of something similar. Simply plug catamaran house boat plans into your computers search engine and see what pops up and suits your fancy. ---

 

To my knowledge there is 1 model that is a trailerable houseboat with folding pontoons.

The big difference between mine and theirs, is that mine accomplishes a similar functionality, but on a larger scale and with more work, longer setup.

I don't think there would be "100's of hours of engineering"..
The pontoons are off the shelf, so weight will dictate the size of them.
Basically what needs to be figured out is the strength, design, and material of the folding framework pieces on the bottom of the cabin and wings.

They will need to carry the weight of the body outward to the pontoons, which are 24 feet from center to center. This should not be very hard to accomplish, if the body weighs just under 10,000lbs (goal), that would be roughly 2000 lbs on each beam assembly (if there are 5) going from pontoon to other pontoon. On a beam 24" or so tall, that is not considered a stretch of engineering to any degree.

Even if each assembly had a breaking strength of 10,000 lbs, thats about a 5x safety factor, which seems decent to me as only 2x overload would simply push the pontoon under the water.

The 1st floor building, by rights, should be very strong by design as it would be a full box frame, not flat beams only under like a flat deck cargo trailer, but build like a framed giant box.

The 2nd floor is simply a light guage assembly of tubing and tinted transparent plastic, that slides right over the bottom building, on little vertical channels every xx feet around the bottom body exterior.
As big as it looks, probably entire thing will be under 1000 lbs.

The beams travelling along the top of the pontoons would also distribute weight and shocks along the pontoons and all of the horizontal frames, meaning that the safety factor would be even bigger that above, because it's impossible to subject one frame assembly to shock or weight without the others. Kind like you could push on a house wall with enough force to snap a wall stud, but it wouldn't be enough because force would also transfer to other wall studs through other material.

As said above, the upper floor is very lean and light, and the bottom floor would contain the structural strength. There would be a thin metal skin on the outside, a teeny big of insulation, and some really thin wood for looks on the inside.

 

Well sounds like you've done your homework--I am a builder not an engineer but common sense dictates you have to start the actual construction at the pontoons. I would consentrate at that phase first--ask specific questions and take it from there. Calculate your total displacement -- over estimate by 25 to 50 % and your pontoons will be able to handle for errors--changes as you go along and for any renovations you make in the future. Good Luck and post photos---Geo.

 

I plan to work it backwards....

Figure the weight of the cabin frame, body, and engine assembly, and then find out how to design supports to hold it up.

It might be better to eliminate those tall lateral supports on the wings, use a thicker tubing in them, and use high tension to "pull" them down, or the body "up" if you will.

 

Well seeing as you know already what you want,and know how to design and build her...get at 'er and be sure to post build pix and such.

 

Why is it that in the spring and fall we seem to get an influx of these sort of concepts? Is it the seasonal changes, maybe different pollen spores in the air. That contraption has so many engineering "issues" you'd do well ,just to make it float without capsizing, let alone folding and motoring down a waterway. What's next, a 55 gallon drum pontoon boats with a 50 MPH target speed, using an electric dish washing machine motor. This isn't directed at you Parkland, it's just we get a lot of "odd" concepts, seemingly around this time of year for some reason. Have you seen the powerboat/sailboat/submarine combo craft thread? Parkland, you do realize there's an over the road height limit, right? Good luck getting any two story structure down the road. Guess how high the power lines and over passes are and why tractor trailers all seem to be the same height? Yeah, good luck with that.

 

If you intend to do the job properly, then yes - there will be literally 100's of hours of engineering work, which should be part of the cost estimates.
If you intend to make it based on just few approximate calculations, then be prepared to a very serious risk of irreversibly throwing bags of money in the river.
Good luck.

 

As I stated above somehwere, the upper story is a light frame with thin tinted transparent plastic, and would slide down over the bottom cabin on channel metal on the outside of the bottom cabin. Thus, it would not be 2 stories tall.

Packed up, it would be roughly 8' or so tall, with 36" pontoons resting on top. It will transport around the same size as a 5th wheel camping trailer.

The top floor will just have portable things like lawn chairs, etc. The roof will sit flush on the bottom floor roof when packed.

The steering console might fold over, or slide down or something, and the top "shell" of a room will slide right over the bottom section.

It is actually a very simple design, but it just looks complicated.

 

Well I got a quote for pontoons,
for 2 40 ft long 36" pontoons, it under 14,000$ including shipping.

While I think it would cost a lot less to build hulls from scratch, I don't think I'd bother... these toons are built by professionals and I don't have to worry about all the extra work.

 

Do they provide structural limits for the pontoons? How much can the boat weigh? Where is the design waterline, etc?

Does the vendor have a website?

 

I resemble that remark!

Ryland