4 Wheel Drive Boat - looking for builder

I bet Leonardo Da Vinci would have loved to try that one.

 

I have to see a video of that gadget in action. I wonder if the snow barrel approach, albeit with engine/barrel mounted on a boat, would carve water faster.

e.g.

http://www.youtube.com/watch?v=zBjlSJf4274

 

That is going to be a tough job making that work I mean... We have here in the Danube Delta some floating tractors called Sega and they where build in the 70's for reed cutting. Those are similar in design with this machine and had hydraulic motors on each wheel to make it steer and advance in the water.

Your design is flawed the way it is as you will not be able to steer it and the moment one of the wheels catches something the whole thing is going to stop no mater how many belts you put on it.

Putting it in reverse will damage the paddles if boat gets stuck. If you want to use it only in open water that's going to be ok but as soon as you enter the vegetation those paddles will fill up with it.

As a toy it might work... but to put your money in it and hope to sell lots of them...

Anyway good luck and I can't wait to see it on youtube just like that screw tractor above... ingenious idea but never made it ask yourself why?

 

All I can think of is this...

http://englishrussia.com/index.php/2007/01/23/russian-car-for-travel-on-swamps/

But I understand that you are looking at a different problem. My question is: how are you defining efficiency? Power used per distance traveled? Top speed per foot of waterline?

 

The 2nd 2 images here show the hydrocopter which uses water friction as an advantage to stay above water and move much faster with less power than traditional paddle wheel designs. That's the theory anyway...

http://www.foils.org/yourown.htm

Porta

http://www.google.com/images?q=hydr...tle&resnum=5&ved=0CDwQsAQwBA&biw=1280&bih=643

 

To JosephT

The best of these were built by Chrysler for the U.S. army.
Lots of rotating surface area. One of the uses is to trench and drain swampy areas.

 

To Portacruise

http://www.foils.org/yourown.htm

I’ve actually drawn this boat? Didn’t think someone would actually build one. The forward speed would not be very impressive. In an aircraft the ability to hover is very useful however on the water you can simply cut the engine!

 

This is only a model to prove the principal.
It can only go in a straight line and I’m aware of that.
For steering there are two choices.
Caterpillar drive or my preference front wheel drive steering.
When you turn the wheel on your car the front tire introduces a side force and works best if you’re not braking or accelerating. However if you had studded tires you could power through the turn by biting into the asphalt. A “Planing Wheel” does bite into the water and will power through a turn.

I define efficiency based on the lift to drag ratio.

A planing hull max’s out at about 5:1.
A hydrofoil (under cavitation speed) is about 6.5:1.
A hovercraft can get up to 10:1.
I hope to be in the 20:1 range or better.

 

Why do you say the forward speed would not be impressive? This should have the ability to go at least as fast as any present planing displacement hull (probably much faster) and use much LESS energy in doing so. This is because of the complete lack of planing hull friction whatsoever. The rotors are INCLINED, not sitting flat to the water in this design so it will not hover under power in this configuration. If you want to hover with the hydrocopter, you simply cut the engine and the backup pontoons keep the thing afloat. There was also mention somewhere in my readings that it could travel over shallows and even land if the rotors are stiff enough, but it would be a stiff ride unless a suspension was rigged up. Help me to see what am I missing here that you can see?

Porta

 

To Portacruise

Ok.

If you could over-swivel your outboard motor so it’s mostly pointed down it would not be efficient but you would still move forward. If you put 4 motors around your boat you could lift the boat and move forward but would you consider this the most efficient way to utilize the power available?

If you look at helicopter principals (in particular why the angle of attack of the blades has to be continually adjusted) you can see some of the problems involved.

Tip speed is the real limiting factor. A fixed hydrofoil blade has a top speed of 40+ knots? before it starts cavitating. So if you spin up these blades to the point where the blade tips are doing 40 knots; any added velocity (moving forward) will start to cause cavitation on the forward swinging blades; before you’ve really gone anywhere.

As far as skin friction goes the spinning blades are producing a very large amount compared to the "speed made good".

 

Thanks,

Porta

 

Now this works!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!ready to sell now.......................
http://www.youtube.com/watch?v=UO4cw565V98 love to use this on lake tahoe............

Here is another.http://www.youtube.com/user/fasttrackdriver
finally got it fixed so you can click on them. If I was rich I'd have lots of these gadgits.

 

Will you pivot each front wheel complete with fancy steering geometry to match or simply articulate the whole vehicle about the centre?

-Tom

 

Tracked

The Caterpillar version has already been done.

http://www.youtube.com/watch?v=ZStHFnAudL4

http://www.gizmag.com/go/6906/picture/31746/

 

To Rambat

I meant caterpillar steering not caterpillar drive. Patents for these types of vehicles date way back. It’s all about efficiency.
From his own website he claims a top speed of 39 mph I would expect to do considerably more with the available HP.