Ultra Cheap River Boat design

[rjmac]

If you want cheap injection molded is expensive....... The most inexpensive route I have seen is vaccumum formed. In terms of size, you will be limited to about 20ft, the moulds are cheap, and there are off-shoots of ABS materials which extreamly durable.

About 8yrs ago I explored this and was up to the point of building the mould, talked to a manufacture, whom at that time was moulding a 16tf bass boat.

Once the mould is made, you can kick out a boat hull about every 10 minutes.

[ultracheapboat]

Hey Gareth, I see you are the owner of the concept and the website "Four Hulls". I must say I think this is a very creative and impressive design: simple, beautiful and practical. I will contact you as soon as I have some backing from our development agency here in Belgium.

Thx for your advice.

[ultracheapboat]

For those who are interested in the issue of riverine transport in developing countries, there's an informative website here: http://ifrtd.gn.apc.org/issues/issues.htm

And here: http://www.ruralwaterways.org

[keithkelley]

I have seen many posts talking about the hull. I would like to make a suggestion about the motor though. In my travels in Southeast Asia I have seen many wooden boats power by a type of improvised outboard that looks like an overgrown weedeater with a prop attached.

Several companies in the US also make a variation of this motor. Most of the companies call them a "mud motor". The designs all consist of a two stroke horizontal shaft motor(usually Briggs and Stratton) with a custom fabricated mounting rig. They have a long shaft attached to a two blad prop. One such vendor is at www.godevil.com

This type of engine is not only cheaper than a traditional outboard it is better suited for use in shallow water. I grew up fishing on the Pea River in Southeast Alabama. During a dry summer not even a short shaft 5.5hp Johnson on a 12ft aluminium jon boat can run very far without grounding out the motor. A godevil reportedly runs in any dept of water that will float a boat.

I hope this input is usefull.

[ultracheapboat]

Thx for the useful input, keithkelly. It's indeed fantastic to see how inventive small boat owners in Bangkok (that's where I've seen them too) are.

[tom28571]

These weedeater type outboards are now called "dragon's tail motors". You might be interested to know that they were manufactured in the USA as early as 1919.

What else is new?

A thought I had on the four hull concept for your application is to mold idenical bow and stern sections with square end transoms. These transoms would have flanges molded around the edge. You could then bend a flat plastic panel around and screw it to the flanges, making a complete hull of any reasonable length. The resulting boat could be a monohull or a multihull. The center section would need stiffening members such a inwhales, seating or stringers. The center section could also be locally molded around a simple locally made form that would be heated. This would allow easier assembly and built in stiffening deck edges.

Sounds plausible to me and could have much more carrying capacity than the four hull models. With two end rotomolds instead of one, the aft one could be made with both ends as a transom so that an outboard could be mounted on the stern.

sure sounds like the answer to me at least.

One angler I know donated one to islanders in zippo habolo islands (samoa?) recently, because of the difficulty and expense they face getting around from island to island etc and the tendency for cyclones to devastate everything quite frequently up there.

It's areoutedly a great place to go fish when weather nice etc and always handy to have a safe reliable boat when you do get there.

The islanders seem to have taken to it with gusto and from all reports it's basically indestructable.

Sounds like a great project idea - wish I could do more to help.

Cheers & good luck with it!.

[ultracheapboat]

thx for your input too, Trouty. I'm gradually getting a better picture of which way to go. The pic is very interesting.

-I'm sorry if I didn't sound very detailed at the beginning of this thread; but as I said, I have no experience with boat building at all. I just noticed the need for cheap boats in my work on "grassroots logistics" in developping countries.

-I could use more advice on engines though... :-)

thx so far to all of you.

[Machnumber2]

I like the injection molded idea. Sure they have alot of wood and labor avail, but if you damage a moded plastic hull, its not that hard to fix with some fiberglass is my guess.

Rotomoulded boats have been made in New Zealand for the last ten years or so. Largest is 6m long. Go to www.galloway.co.nz for more detail

Bamboo is the fastest renewable resource on the planet as far as building materials go and will grow in almost any warm climate. Bamboo has been used to build boats and rafts since humans first started eating fish. Check out a few of it's uses at http://www.bambus.de/infos/1000/inde...gorie=building
Good luck.
The Dude

I am the designer of a lightweight conventional outboard motor, weighs
11and1/2 - 12lbs. It was tested at Mississipi State University as developing
8.8 horsepower at the prop. It is excellent for shallow water use in that you
can change the prop depth without changing the incidence of prop, therefore
maintaining centerline thrust. It can be built " as new " for under $ 200.00 USD, parts to undertake this project can be purchased virtually anywhere.
There is no maintenance to perform. I currently sell the plans for $ 29.95 USD
Plus $ 3.95 shipping and handling. I can be contacted at FlyBy750kts@aol.com. I forgot to mention it can be built in as little as two days - Thanks, Roy

[gonzo]

I am skeptical of "mainteinance free" claims. All mechanical objects require upkeep for wear and tear.