Catapillar Engine - Page 2

Kapitan · 05-09-06, 05:26 AM

Not so fast the russians have used rubber propellors on thier Bravo class target submarines but that was because they fired dud torpedos and had them bounce off the hull so if the torpedo did come up the rear there was little chance that the torpedo would fracture or smash apart the metal screw simply because rubber bends.

05-09-06, 07:37 AM

The caterpillar in the book were prop sets inside the hull while in the movie, the caterpillar was something like an ionengine. Don't laugh, it's possible by physics and there are test ships in the world with such an engine. The most known should be the japanese "Yamato". The drawback of this enginetype is, that it needs saltwater, up to 75% loss in brack and almost no power in sweet.
It ionises the salt in the water and creates enough push to move the ship.

compressioncut · 05-09-06, 10:08 AM

Quote:

Originally Posted by Bubblehead Nuke

Quote:

Originally Posted by Deathblow

My guess is that the stators are probably made of steel whereas traditional props are probably titanium.

Normal screws are made of bronze.The impellors???? no idea..

Quote:

There has to be some tangible advantage to them since everyone is making the switch now. My reading says that a pumpjet can achieve an equal amount of thrust with a smaller diameter than a traditional screw, something about better use of the blade ends for thrust production iirc.

The noise of the screw turning is more 'channeled' in a fore and aft direction. With the impellor housing you get a baffling effect and that cuts down on your side aspect noise level. One other thing is blade count. What IS the number of impellor blades and how does something like DEMON interprept this into a TPK.

(edited to censor myself - it's no different than a propeller)

05-09-06, 05:26 AM	#16
Kapitan Sub Test Pilot Join Date: Mar 2005 Location: UK + Canada Posts: 7,130 Downloads: 77 Uploads: 7	Not so fast the russians have used rubber propellors on thier Bravo class target submarines but that was because they fired dud torpedos and had them bounce off the hull so if the torpedo did come up the rear there was little chance that the torpedo would fracture or smash apart the metal screw simply because rubber bends. __________________ DONT FORGET if you like a post to nominate it by using the blue diamond Find out about Museum Ships here: https://www.museumships.us/ Flickr for all my pictures: https://www.flickr.com/photos/131313936@N03/ Navy general board articles: https://www.navygeneralboard.com/author/aegis/

05-09-06, 07:37 AM	#17
gmuno Stowaway Posts: n/a Downloads: Uploads:	The caterpillar in the book were prop sets inside the hull while in the movie, the caterpillar was something like an ionengine. Don't laugh, it's possible by physics and there are test ships in the world with such an engine. The most known should be the japanese "Yamato". The drawback of this enginetype is, that it needs saltwater, up to 75% loss in brack and almost no power in sweet. It ionises the salt in the water and creates enough push to move the ship.