"Hovering" or submerged floating

planecrazydale · 08-29-06, 04:25 PM

hi all,

just thought i would put my 2 cents in on the topic of hovering when submerged. i recently saw a couple of people say it couldn't be done and that in real life the sub would have to have some power on in order to stay at the same depth without sinking.

i found the following excerpt from a WWII trivia site. it is a declassified book re:german submarines and tactics. just thought i would throw this out there so that people don't feel they are being "unrealistic" if they hover for a little bit in sh3.

"43. Can submarines remain stopped when submerged, without lying on the bottom?

A very well trimmed boat may do so for about 5 minutes at a time by juggling with her periscope. For longer periods it is only possible in a few localities where layers of different density. occur in the water, e. g., in the Baltic, Cattegat, and Sea of Marmora, where occasionally a boat may lie submerged almost indefinitely1 with all machinery stopped, resting on a layer of salt water.

1 Two German submarines, sent at outbreak of war to watch the southern exits from the sound and Great Belt, succeeded in thus lying submerged, with their motors stopped most of the time, for about 23 hours out of the 24, on 7 consecutive days."

hope that helps,

dj

P_Funk · 08-29-06, 05:20 PM

Cool. Talk about the esoteric side of seamanship. Imagine how long it took to figure that out.

Sailor Steve · 08-30-06, 11:02 AM

What site, what book? You must give details that can be checked by others.

I still say show me when anyone lay in wait for a convoy at periscope depth doing that.

clive bradbury · 08-30-06, 11:17 AM

Quote:

Originally Posted by Sailor Steve

What site, what book? You must give details that can be checked by others.

I just googled the quote, Steve:

http://www.history.navy.mil/library/...onipubno32.htm

An interesting read - US reprinting of a British Intelligence pamphlet. One slight problem, though, which the orignial poster does not seem to have noticed - pamphlet is dated 1918, and is thus 20 years out of date...and therefore as much use for WW2 boats as a one-legged man at an arse-kicking party...

sergbuto · 08-30-06, 11:23 AM

Quote:

Originally Posted by clive bradbury

...and therefore as much use for WW2 boats as a one-legged man at an arse-kicking party...

Why? The principles are the same.

clive bradbury · 08-30-06, 11:35 AM

[/quote]Why? The principles are the same.[/quote]

1. Because the designs were different, and therefore we are not comparing like with like.

2. With next to no effective ASW measures in WW1, the Great War commanders had the luxury of messing around with their scope that WW2 did not have.

3. Was the intelligence accurate in the first place?

4. I'm not saying that it could not be done , but has anyone come up with a record of WW2 subs of any nation trimming the boat in this fashion?

SteamWake · 08-30-06, 12:09 PM

Quote:

Originally Posted by planecrazydale

A very well trimmed boat may do so for about 5 minutes at a time by juggling with her periscope.
dj

What the heck does juggling with here periscope mean ? and how would effect boat trim ?

08-29-06, 04:25 PM	#1
planecrazydale Gunner Join Date: Aug 2006 Location: Calgary, AB, Canada Posts: 99 Downloads: 106 Uploads: 0	"Hovering" or submerged floating hi all, just thought i would put my 2 cents in on the topic of hovering when submerged. i recently saw a couple of people say it couldn't be done and that in real life the sub would have to have some power on in order to stay at the same depth without sinking. i found the following excerpt from a WWII trivia site. it is a declassified book re:german submarines and tactics. just thought i would throw this out there so that people don't feel they are being "unrealistic" if they hover for a little bit in sh3. "43. Can submarines remain stopped when submerged, without lying on the bottom? A very well trimmed boat may do so for about 5 minutes at a time by juggling with her periscope. For longer periods it is only possible in a few localities where layers of different density. occur in the water, e. g., in the Baltic, Cattegat, and Sea of Marmora, where occasionally a boat may lie submerged almost indefinitely1 with all machinery stopped, resting on a layer of salt water. 1 Two German submarines, sent at outbreak of war to watch the southern exits from the sound and Great Belt, succeeded in thus lying submerged, with their motors stopped most of the time, for about 23 hours out of the 24, on 7 consecutive days." hope that helps, dj

08-29-06, 05:20 PM	#2
P_Funk Ocean Warrior Join Date: Jun 2005 Location: Canada, eh? Posts: 2,537 Downloads: 129 Uploads: 0	Cool. Talk about the esoteric side of seamanship. Imagine how long it took to figure that out. __________________

08-30-06, 11:35 AM	#6
clive bradbury Captain Join Date: Jun 2004 Location: stoke-on-trent, UK Posts: 492 Downloads: 105 Uploads: 0	[/quote]Why? The principles are the same.[/quote] 1. Because the designs were different, and therefore we are not comparing like with like. 2. With next to no effective ASW measures in WW1, the Great War commanders had the luxury of messing around with their scope that WW2 did not have. 3. Was the intelligence accurate in the first place? 4. I'm not saying that it could not be done , but has anyone come up with a record of WW2 subs of any nation trimming the boat in this fashion? Last edited by clive bradbury; 08-30-06 at 11:45 AM.

08-30-06, 11:02 AM	#3
Sailor Steve Eternal Patrol Join Date: Nov 2002 Location: High in the mountains of Utah Posts: 50,369 Downloads: 745 Uploads: 249	What site, what book? You must give details that can be checked by others. I still say show me when anyone lay in wait for a convoy at periscope depth doing that.