Submarine questions

troopie · 01-18-13, 07:30 AM

Unkie Neil posted this youtube link to a USN training vid not long ago:

http://www.subsim.com/radioroom/showthread.php?t=200577

It won't answer your in-game questions but it provides great insight into the workings of a WWII sub

ETR3(SS) · 01-18-13, 08:09 AM

With regards to your second question, if you're in a situation where you are blowing your ballast tanks you probably are intending to surface. Otherwise if you just wanted to change depth, you use the planes. So no, you wouldn't blow ballast and then turn around and re-flood the tanks. To do so would be a waste of a limited resource, compressed air.

Sailor Steve · 01-18-13, 01:52 PM

Quote:

Originally Posted by troopie

Unkie Neil

You may be hearing from Onkle Neal soon.

Schroeder · 01-20-13, 12:37 PM

Quote:

Originally Posted by Sailor Steve

You may be hearing from Onkle Neal soon.

Actually it's Onkel Neal.

Busted again.

Sailor Steve · 01-20-13, 02:41 PM

Quote:

Originally Posted by Schroeder

Actually it's Onkel Neal.

Busted again.

Very true. My German isn't what it once was. In fact my German never was what it once was.

"Your" absolutely right.

ABBAFAN · 01-21-13, 05:30 PM

I meant as a way of slowing the ascent or even to prevent it from speeding up as more and more balast is expelled by the expanding air already in the tanks.
Perhaps similar to rising and descending in a gas balloon?

On the other hand, would decreasing water density compensate anyway by reducig the boat's bouyancy as she rises?

ETR3(SS) · 01-21-13, 07:36 PM

Quote:

Originally Posted by ABBAFAN

I meant as a way of slowing the ascent or even to prevent it from speeding up as more and more balast is expelled by the expanding air already in the tanks.
Perhaps similar to rising and descending in a gas balloon?

On the other hand, would decreasing water density compensate anyway by reducig the boat's bouyancy as she rises?

Well in a hot air balloon lift is generated by the hot air in the balloon itself. As the air cools it descends thus making it necessary to heat the air trapped within the balloon to maintain altitude or to ascend. That's pretty well know.

A submarine operates on a completely different principle. When it submerges it takes on water in its ballast tanks to maintain a state of neutral buoyancy. Depth changes are accomplished by the use of the control planes. Once submerged the main ballast tanks aren't touched except to surface the boat. There's no need to blow water out or take water on except for when your displacement would change (consuming food stores, firing torpedoes, etc) and there is an auxiliary system for this purpose.

As for your second question about water density affecting buoyancy, I'll hold off on answering that for now.

ABBAFAN · 01-22-13, 06:36 AM

I know about hot air balloons, I was making the comparison with gas balloons which are rather different.

Do they close the valves at the bottom of the ballast tanks once blowing has been done and the vessel is on the way to the surface?

01-18-13, 07:30 AM	#1
troopie Captain Join Date: Oct 2010 Location: Oz Posts: 507 Downloads: 33 Uploads: 0	Unkie Neil posted this youtube link to a USN training vid not long ago: http://www.subsim.com/radioroom/showthread.php?t=200577 It won't answer your in-game questions but it provides great insight into the workings of a WWII sub __________________ Serial pest

01-18-13, 08:09 AM	#2
ETR3(SS) Ocean Warrior Join Date: Dec 2007 Location: Between test depth and periscope depth Posts: 3,021 Downloads: 175 Uploads: 16	With regards to your second question, if you're in a situation where you are blowing your ballast tanks you probably are intending to surface. Otherwise if you just wanted to change depth, you use the planes. So no, you wouldn't blow ballast and then turn around and re-flood the tanks. To do so would be a waste of a limited resource, compressed air. __________________ USS Kentucky SSBN 737 (G) Comms Div 2003-2006 Qualified 19 November 03 Yes I was really on a submarine.

01-21-13, 05:30 PM	#6
ABBAFAN Commander Join Date: Sep 2001 Posts: 456 Downloads: 0 Uploads: 0	I meant as a way of slowing the ascent or even to prevent it from speeding up as more and more balast is expelled by the expanding air already in the tanks. Perhaps similar to rising and descending in a gas balloon? On the other hand, would decreasing water density compensate anyway by reducig the boat's bouyancy as she rises? __________________ CHOOSE RFA! LESS GRAFT, MORE PAY.

01-22-13, 06:36 AM	#8
ABBAFAN Commander Join Date: Sep 2001 Posts: 456 Downloads: 0 Uploads: 0	I know about hot air balloons, I was making the comparison with gas balloons which are rather different. Do they close the valves at the bottom of the ballast tanks once blowing has been done and the vessel is on the way to the surface? __________________ CHOOSE RFA! LESS GRAFT, MORE PAY.