Banner Ad 1

Caterpillar Drive

R/C Submarine modelers

Postby ToothFairy » Mon Mar 29, 2004 1:02 pm

Any one know of a way to make something simmiler to the caterpillar Drive from The hunt for Red October?
ToothFairy
ToothFairy
Registered User
 
Posts: 11
Joined: Thu Mar 11, 2004 12:49 pm
Location: Kent, South East UK

Postby JWLaRue » Mon Mar 29, 2004 3:02 pm

...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
Rohr 1.....Los!
User avatar
JWLaRue
SubCommittee Member
 
Posts: 3857
Joined: Wed Aug 31, 1994 6:00 pm
Location: Annapolis, MD

Postby Novagator » Mon Mar 29, 2004 4:15 pm

What Jeff said, there is no way to make a real one.
John Cottingham
Sub Committee Member #2721
User avatar
Novagator
SubCommittee Member
 
Posts: 823
Joined: Wed Aug 27, 2003 7:24 am

Postby fbradasc » Wed Mar 31, 2004 11:49 am

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)
User avatar
fbradasc
Registered User
 
Posts: 26
Joined: Fri Feb 21, 2003 12:29 pm
Location: Torino, ITALY

Postby Bob the Builder » Wed Mar 31, 2004 2:44 pm

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.

Image


Another good link concerning propelling a model boat through salt water with this propulsion system:

Hope this helps a bit.UBC site.




Edited By Bob the Builder on 1080758870
Bob Martin,
RCSub homepage: http://www.rc-sub.com
User avatar
Bob the Builder
SubCommittee Member
 
Posts: 777
Joined: Fri Feb 21, 2003 9:40 am
Location: Naples, FL

Postby natesubs » Wed Mar 31, 2004 10:49 pm

Bob the Builder wrote:Another good link concerning propelling a model boat through salt water with this propulsion system:

Hope this helps a bit.UBC site.

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.
natesubs
Registered User
 
Posts: 12
Joined: Fri Mar 05, 2004 1:03 pm
Location: Lubbock, TX

Postby Interpol » Thu Apr 01, 2004 3:02 am

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
Registered User
 
Posts: 47
Joined: Mon Mar 29, 2004 12:52 am
Location: Orange County, CA

Postby Interpol » Thu Apr 01, 2004 3:05 am

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)
Interpol
Registered User
 
Posts: 47
Joined: Mon Mar 29, 2004 12:52 am
Location: Orange County, CA

Postby Bob the Builder » Thu Apr 01, 2004 12:17 pm

Interpol wrote: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...
Bob Martin,
RCSub homepage: http://www.rc-sub.com
User avatar
Bob the Builder
SubCommittee Member
 
Posts: 777
Joined: Fri Feb 21, 2003 9:40 am
Location: Naples, FL

Postby Interpol » Thu Apr 01, 2004 1:32 pm

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.
Interpol
Registered User
 
Posts: 47
Joined: Mon Mar 29, 2004 12:52 am
Location: Orange County, CA

Postby JWLaRue » Thu Apr 01, 2004 2:04 pm

>>> 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
Rohr 1.....Los!
User avatar
JWLaRue
SubCommittee Member
 
Posts: 3857
Joined: Wed Aug 31, 1994 6:00 pm
Location: Annapolis, MD

Postby Interpol » Thu Apr 01, 2004 6:12 pm

JWLaRue wrote:>>> 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.
Interpol
Registered User
 
Posts: 47
Joined: Mon Mar 29, 2004 12:52 am
Location: Orange County, CA

Postby JWLaRue » Thu Apr 01, 2004 10:00 pm

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
Rohr 1.....Los!
User avatar
JWLaRue
SubCommittee Member
 
Posts: 3857
Joined: Wed Aug 31, 1994 6:00 pm
Location: Annapolis, MD

Postby Interpol » Thu Apr 01, 2004 11:50 pm

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

My apologies :D
Interpol
Registered User
 
Posts: 47
Joined: Mon Mar 29, 2004 12:52 am
Location: Orange County, CA


Return to R/C Modeler

Who is online

Users browsing this forum: No registered users