Modern Paddle Wheel/Amphibious Craft.

Hi everyone.

Just spent the last few hours looking through heaps of great posts. Thanks for all the info.

As is with probably most of you when you first register, I've got a question about building a boat. We'll maybe not quite a boat, but a hybrid.

The goal: getting up a river, unpassable by most or all boats - without portage. It floats when it needs to and 'crawls' over rocks and small obsticals when it needs to.

In New Zealand, we've got a network of some fantastic rivers. The ones in particular to our area are not deep or fast moving, but they vary and change with each season/flood. It's usually a mix of braided gravel, or gorge, with some clumps of rapids reaching grade 3 or 4, but mostly 1 or 2.

We'll, at least the rivers I want to fish and hunt.

Problem is access. I often walk, but obviously this doesnt get me up or down stream very far. The rivers are often crossable,

at about waist deep. But, every so often (and some times very often), there will be a small, but sharp elevation drop, with rocks/gravel protruding. Or, really shallow water...etc. etc. You get the picture. Often, jet boats are used, but even they can't get past many spots.

Besides, I dont need to get up the river in a hurry. I just need to get upriver.

So, here's what I have in mind. Hoping to hear your thoughts on this.

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I'd like to look at some kind of modified paddle wheel. But instead of merely a paddle wheel, I'd like to have mounted next to the paddles, rubber wheels that would be used to crawl over and up rocks.

Originally, I'd thought about modifying a Mackenzie river drift boat, mounting a 2 paddles either side of the bow and another 2 at the stern. Then, I'd vertically mount an electric motor at either end, riving a differential gearbox, which would spin the paddle wheels. Just like a car.

Problem is, the paddles and tires need to be different sizes. The paddles, from what I've read on another thread need to be quite big in diameter.

Version 2 is to not build a boat at all really, just have each of the paddles float individually, with a 'pod' in the middle held slightly above the water.

Thoughts/Opinions?

 

I've proposed this in an earlier thread. How about a punt shape boat with a rubber track as the bottom? Should work on any surface, also the not so level ones.

Lurvio

 

I am just curious how much water you generally have, and what the bottom is in the shallows. There are a lot of boats that are designed and run in 1 inch or less of water, but they have to be spicifically designed to do this. South Louisiana has a whole host of mud boats that really operate in thin mud more than they do actual water.

The other option would be a small hovercraft which would allow you both speed and the ability to portage over dry land pretty nicely. And there are experts around here who can help guide you to a reasonable home build if you wanted.

You might also consider an airboat. The good ones can travel on land and water, and due to a thick coting on the bottom can actually run down the road, though highly abrasive surfaces can scrape this off at high speeds.

As for designing a whole new propulsion system... Not that it might not work, but it will be expensive to design and test, and unless it happens to be a passion of yours probably not worth the effort compared to building/buying something that already does what you are looking for.

 

Stumble is probably right. The original proposal was for a guy who wanted to invent a whole new propulsion system.

 

I'd second the hovercraft idea. There are mountains of patents for new propulsion systems, and only one or two have been done more than once.

 

Here's something to think about.

And floating is entirely optional!

 

Thanks for all your replies!

In answer to your question Stumble... there's generally plenty of water and the bottom is either sand, gravel or boulders/rocky. Not really what I'd call muddy.

I think the primary challenge here is the drops in the river, which difficult or impossible to pass. There are a few I've looked at that I thought maybe a jet boat going 50 miles an hour might handle.. but yikes. that's not me. I dont want to move that fast next to very solid objects.

Because this heads up into the mountains, these drops are common, but thankfully there are large stretches with no significant drops or waterfalls. Maybe a few feet at a time, but on a slope, not a cliff.

Otherwise, on the normal and 90% of the river there are stretches that would easily take a jet or even outboard motor.

 

Lurvio - cool! Is the post still up somewhere? I did a quick search, but couldnt find one that looks like it.

 

Thanks for the hovercraft suggestions and, yeah - I've definately considered them but for a few reasons I'd rather not. Noise being one.

 

Jim_Hbar - Thanks! This is the closest of what I've seen, and would probably work, but not sure I could get the tracks to work properly. Feel a lot more confident with traditional wheels, etc.


But this is definately still in the running.

 

I dont mind some fabrication. Comfortable with wood and some metal work. Access to a few engineer friends might come in handy with the specifics of the dimentions, etc.

So, here's a bit more to my line of thinking. You might all think I'm crazy...

I thought at first, maybe a beefed up one of these AutoCanoes: http://www.autocanoe.com/ - but with a Mackenzie River Drift boat design and 2 wheels up front and again in the rear.

To simplify, I ended up thinking, why not just have essentially 4 large drums/barrels, which provided the floatation and which had paddels attached. In the middle would then be the platform where you sat.

It might look a little funny, because from reading past posts, the drums would need to be large in diameter to get enough forward force and not just make a good 'river frother'. the platform in the middle would be just big enough to hold batteries, 2 people and 1 or 2 deer or a few trout. )

A little off topic - but I came accross the design of out of an old popular mechanics online. It's a 'screw' type propulsion, but screws out the side. I think the design has some serious flaws though. not sure it would actually have 1/2 a chance of working.

 

Hi, I have similar situations on rivers in my area. My solution was a very light weight one man inflatable cat with an electric long tail drive. Fabric is tough and springy enough so you get no damage from rocks. It is light enough to carry on my back, or with a wheel (for some heavier models) when I have to portage. As for going up rapids- if they are deep enough, I tie a line to one of the pontoons at a position so it catches the rushing water and pushes away from the bank and into the middle of the flow. Then I just walk upstream on the bank, effectively pulling and "sailing" the boat up stream until I get past the rapids. This "sailing" is done when I don't have enough draft or power to push up the rapids and works well since the boat is lighter without my weight on board. If the rapids are too shallow, then can hand carry or roll around the rapids. The key for me has been to keep the whole thing as small and lightweight as possible. This means 3 knots top speed, but then I'm not in a hurry as you have indicated.

See post 53 & 54 : http://www.boatdesign.net/forums/inboards/prop-shaft-systems-24636-4.html

See weedeater conversions, mud motors, long tails on this:

http://www.boatdesign.net/forums/diy-marinizing/

Here's the smallest of the boats: http://www.4seasonsfly.com/11939/234630/Float-Tubes/Outcast-Discovery-Trekker.html

Hope this helps.

Porta

 

Porta - Does that help?! That's an Awesome suggestion!

It makes a lot of sense and would be a heck of a lot simpler.

The link to the inflatable cat is one small boat though. Is that the size you're using or something bigger?

How big do you think a person could go?

I wonder if that thai styles long tail weedeater would be enough to propell just a regular old inflatable (a smaller version of the ones they do the white water rafting in).

Enough umph you think?

 

http://www.trademe.co.nz/Trade-Me-Motors/Boats-marine/Motorboats/auction-282262685.htm

Too big?

This one's probably a better size.
http://www.trademe.co.nz/Trade-Me-M...ies-rowboats/Inflatable/auction-284437162.htm

This is digressing from boat-building exactly, but if I can get a sense for what will do the trick from your experiences that would be great.

 

Or even one of these thundercats.
http://www.trademe.co.nz/Trade-Me-Motors/Boats-marine/Motorboats/auction-286043730.htm

Or this, but it might be too light weight for rocks/abuse.
http://www.trademe.co.nz/Trade-Me-M...ies-rowboats/Inflatable/auction-285296631.htm

There's going to be two of us all the time anyways. So 2 people to carry the boat when needed.