Caterpillar Drive

[toothfairy]

Any one know of a way to make something simmiler to the caterpillar Drive from The hunt for Red October?
ToothFairy

[JWLaRue]

...a ducted fan (pumpjet) comes

...a ducted fan (pumpjet) comes to mind.

A good example of this would be the Flying Sub model built by David Merriman from a Rick Teskey hull.

-Jeff

[novagator]

What Jeff said, there is

What Jeff said, there is no way to make a real one.

[fbradasc]

According to the Tom Clancy's

According to the Tom Clancy's book the Caterpillar silent propulsion systems is a kind of crawler track (like that on a Caterpillar tractor)

This is the principle (follow the link)

or rotate this 90° (follow the link)

[bob the builder]

Umm.... not really.

Here is a

Umm.... not really.

Here is a summary from what I've been able to find out about the system]Magnetohydrodynamic (MHD) propulsion is a type of vessel drive where thrust generates through interaction of magnetic and electric field. The main characteristic of this propulsion is that there are no mobile parts, no propeller noises and no vibration. As a completely new type of vessel drive, magnetohydrondynamic propulsion (MHD) is very useful for military necessities or submarine drive.[/b]




Another good link concerning propelling a model boat through salt water with this propulsion system]UBC site.[/url]



Edited By Bob the Builder on 1080758870

[natesubs]

Another good link concerning propelling

Another good link concerning propelling a model boat through salt water with this propulsion system]UBC site.[/url]

Wow, that is a very interesting link. Who knows, with the new superconductors they keep generating, maybe this technology would actually be able to come to life.

[interpol]

I remember seeing a ferry

I remember seeing a ferry in Hong Kong (Can't remember where I was at the time, it was either Hong Kong or Singapore, all one drunken memory merged together) that had this technology on it, it is nothing new, as this was well over five years ago.

It just basically pushes water through by use of magnetic force, much like the new "super" electro-magnet guns are doing.

I doubt that we will ever get one small enough to work on subs in the RC scale. At least, not until my kids are old enough to drive.

[interpol]

Also, don't forget that Salt

Also, don't forget that Salt water is a totally different medium than fresh water, as salt water is more conductive that fresh water.

salt water generally has 4homs(1/4ohm resistance per cubic meter) and fresh water generally has .05(20 ohms per cubic meter) (if I remember correctly, please don't shoot me if I am off a little)

[bob the builder]

I doubt that we will

I doubt that we will ever get one small enough to work on subs in the RC scale. At least, not until my kids are old enough to drive.

I believe that the gist of the website that I posted was that he was going to get a small boat model to operate using this idea.

I'm sure that the force he managed to produce was pretty small compared to what we're currently getting from propellors, but it may not be as long as you think before someone has one working...

[interpol]

What speed will the boat

What speed will the boat be going after 30 s?

a = v/t therefore v = at = (0.04m/s2)(30s) = 0.0012 m/s = 1.2 mm/s

All at 3amps of current.


I am going to play around with this on the weekend, and let you guys know what I find, the only problem is fitting it inside of a sub, since most space is already taken up.


I'll try a 36" long, 4" wide version of this, and see what kind of force we can get out of it.

[JWLaRue]

>>> I remember seeing a

>>> I remember seeing a ferry in Hong Kong that had this technology on it, it is nothing new, as this was well over five years ago.

I must admit that I find this difficult to rationalize. If this were to be economical when used as a commercial ferry propulsion system, then the military would likely have been using this for years. Given the power available through a nuclear reactor, it'd be a no-brainer!

Could the ferry have been using a ducted pumpjet? To the external observer, they both 'push' water.

-Jeff

[interpol]

>>> I remember seeing a

>>> I remember seeing a ferry in Hong Kong that had this technology on it, it is nothing new, as this was well over five years ago.

I must admit that I find this difficult to rationalize. If this were to be economical when used as a commercial ferry propulsion system, then the military would likely have been using this for years. Given the power available through a nuclear reactor, it'd be a no-brainer!

Could the ferry have been using a ducted pumpjet? To the external observer, they both 'push' water.

-Jeff

Well, I am sorry its hard for you to rationalize, but it was not a ducted fan jet.

It was a small ferry, only had people on it, no cars, it was more of a small boat than ferry size, but they were using it. It was going rather slow, and I also remember watching the news report that followed them using it for that day.

The military does use this technology, or is developing it rather, but not for pushing water

Besides, it is impractical to use it for any real purpose application, as it takes way too much energy to get it going, which is why it was only used for one day in the demonstration that I saw.

[JWLaRue]

Ahhh!!

...you left out the part

Ahhh!!

...you left out the part about it being a demonstration...

That's not difficult to understand. What you posted left the impression that MHD was being used on an operational ferry....and that is what is/was hard to rationalize.

-Jeff

[interpol]

You know, in reading my

You know, in reading my own post, I realized that it did make it sound like they were actually using it daily.

My apologies