Alternative "Caterpillar" Propulsion System?

[mbuet]

Has anyone heard of a real-life commercially available "caterpillar" drive like the one mentioned in the "Red October"? I know there are several USPTO Patents on this type of propulsion system, but I have yet to hear about one that can be purchased and "played" with...
Info, anyone please?

Thanks

MichaelB

[cthippo]

Welcome aboard, Michael

Depends on if you mean the book or the movie.

In the book the caterpillar was a set of turbines in a pipe, similar to a jet engine. I'm sure the idea has been experimented with, but as far as I know none are currently in existence. The closest thing I'm aware of is pumpjet propulsers which are basically a propeller in a long shroud.

In the movie the caterpillar was a magneto-hydrodynamic drive. The Japanese built a fair sized (~15M) prototype vessel which is now on display.

Both technologies, while feasible, don't currently offer enough advantages over conventional propulsion to be of interest. In short, both are cases of soloutions in search of a problem.

[hoytedow]

Here's a little sump'n sump'n pump'n.

[mbuet]

Thanks for the reply - Based upon that, I was mistaken when asking about the caterpillar drive - I did not realize it was portraying the MHD.
What I am looking for is basically a "squid-drive", working on the anular contractions principle that propel the squids at prodigious acceleration rates and incredible underwater speeds, as I have witnessed many times while scuba-diving. I thought the Red October was supposed to be one of these types of drive.
Has anyone heard of something like that out there?
Michae

[hoytedow]

I think that would be some sort of diaphram pump.

[mbuet]

The drive I am looking for is like a squid action: Annular contraction that expells the water in a jet, propulsing the squid backward at great acceleration & speed.

[SheetWise]

What you're suggesting, with the squid, is a reciprocating action -- and while you may be able to minimize the cost, you should be thinking about a nonreciprocating action.

[mbuet]

Not sure I understand what you mean - Sequential annular contractions is what I had in mind, since that is what the muscles inside the squids are doing to propell the water out through its jets.
What I am looking for is if anyone has yet created such device, which is practically similar to a peristaltic pump, in a way.

BTW: Lake Bartlett is all water, no sand.... :-) Lol.

[hoytedow]

This may be the closest to what you want, if I understand you correctly. http://upload.wikimedia.org/wikipedi...ert-bewegt.gif

[hoytedow]

It looks like it would play hell on the tubing.

[cthippo]

Originally Posted by hoytedow

This may be the closest to what you want, if I understand you correctly. http://upload.wikimedia.org/wikipedi...ert-bewegt.gif

That's basically how IV pumps work. You can't use a standard impeller pump for blood because it will destroy the cells.

As for the OP, I'm wondering about sustaining that speed. Basically, you're talking about a diaphragm pump, but instead of a linear motion it's using a radial motion. In both cases a water filled space is being made smaller and so the water is squirted out, propelling the vessel (or squid) forward.

Having never spent time up close and personal with squid, I'm wondering if they can sustain that motion, or if it's just a sprint to get away from predators. It has to take a substantial amount of energy to accelerate their bodies through the water.

I'm not aware of anyone working on this as a propulsion technology. I can see it working with an annular cylindrical air bladder, but moving enough fluid, either air or hydraulic, to fill and empty the bladder that quickly seems like a problem.

Let us know if you build one!