Speed or Cavitation - Page 2

TLAM Strike · 04-24-06, 08:17 PM

Quote:

Originally Posted by Kapitan

Generaly the foxtrot was recorded making its fastest speed at 26 knots, so i would have no doubt that some conventionals could hit 30 or even 33 or more knots.

ok its going to depleate the batters very quick but that boost of speed could be used for emergencys.

A WWII Gato (A boat with Diesel Electric so its running electric motors when surfaced) could make something like 21 and a half knots on diesels pushed beyond spec. You put sufficient power in to the motor you can get some real speed at the risk of burning up the motors. A burned out motor is better than flaming crushing death at times.

Bubblehead Nuke · 04-24-06, 08:52 PM

Quote:

Originally Posted by Deathblow

That's very interesting :hmm: Makes sense. Is that one of the additional reseasons that SSKs on electric power can be quieter than SSNs, not just because of lack of the need for reactor coolant circulation, but because electric moters don't require reduction gears? Or do they? Guess I'll look it up

As I understand it, electric motors are wound directly on the shaft. thus no need for gears at all. The motors are what turn the screws at all times. The source of the electical power is what varies. Batteries for normal submerged ops and diesels (with the battery floating for a charge) for surface/snorkel ops.

Bubblehead Nuke · 04-24-06, 09:07 PM

If talking about speed on a batttery the USS Albacore, while a non-combat vessel, topped out at 30+ knots. According to some reports, it was faster than the Skipjack class and was the fastest US submarine until the Seawolf class come onto the scene.

Moral: Battery does NOT equal slow speed.

TLAM Strike · 04-24-06, 09:14 PM

Quote:

Originally Posted by Bubblehead Nuke

As I understand it, electric motors are wound directly on the shaft. thus no need for gears at all. The motors are what turn the screws at all times. The source of the electical power is what varies. Batteries for normal submerged ops and diesels (with the battery floating for a charge) for surface/snorkel ops.

On a diesel-electric drive yes but not on a direct drive diesel.

Are there still direct drive boats? :hmm:

Kapitan · 04-25-06, 04:44 AM

I dont think so, but there is also AIP to bring into this.

View Poll Results: Which prop design is better
Slower threshold for cavitation but higher top speed	5	35.71%
Higher threshold for cavitation but slower top speed	9	64.29%
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04-25-06, 04:44 AM	#20
Kapitan Sub Test Pilot Join Date: Mar 2005 Location: UK + Canada Posts: 7,132 Downloads: 77 Uploads: 7	I dont think so, but there is also AIP to bring into this. __________________ 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/

04-24-06, 09:07 PM	#18
Bubblehead Nuke XO Join Date: Feb 2006 Posts: 435 Downloads: 5 Uploads: 0	If talking about speed on a batttery the USS Albacore, while a non-combat vessel, topped out at 30+ knots. According to some reports, it was faster than the Skipjack class and was the fastest US submarine until the Seawolf class come onto the scene. Moral: Battery does NOT equal slow speed.