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View Full Version : Is the snorkel correct?



TheFastFreddie
05-19-2005, 09:59 PM
I just got the snorkel option and decided to test it out. I was able to reach 15kts underwater with my IXC by changing it to standard and going flank. I'm just asking if this is accurate historically.

TheFastFreddie
05-19-2005, 09:59 PM
I just got the snorkel option and decided to test it out. I was able to reach 15kts underwater with my IXC by changing it to standard and going flank. I'm just asking if this is accurate historically.

U-49
05-19-2005, 10:12 PM
A IXC can go 15 knots submerged? Are you sure you weren't in a type XXI boat? http://forums.ubi.com/images/smilies/blink.gif

alanschu
05-19-2005, 10:19 PM
I've noticed in this game that you reach higher speeds using the diesels and a snorkel than just being submerged with the electrics.


I have no idea if this is or is not accurate though.

ShinyBaldy
05-19-2005, 10:36 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by alanschu:
I've noticed in this game that you reach higher speeds using the diesels and a snorkel than just being submerged with the electrics.


I have no idea if this is or is not accurate though. </div></BLOCKQUOTE>

I would imagine the uboat being a tad-bit slower at flank on diesel underwater than above water... given the hull design for the time (aside for the TypeXXI)..

15knots sounds reasonable.

alanschu
05-19-2005, 10:38 PM
That is the case.


I can imagine the diesels could be more powerful, as power conservation would definitely not be as much of an issue as with the electrics (same with power output)

TheFastFreddie
05-19-2005, 11:12 PM
I checked on Uboat.net and it said the max speed should be 6kts or the air mask would break off. Not a big problem because I don't plan on going flank with the snorkel up anyway but could be an exploit.

U-49
05-19-2005, 11:13 PM
I thought the total drag would've been sufficiently higher underwater than on the surface. At least enough to reduce the submerged speed by a larger percentage, even considering the hull design and diesel propulsion.

Interesting.

ShinyBaldy
05-20-2005, 02:14 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by U-49:
I thought the total drag would've been sufficiently higher underwater than on the surface. At least enough to reduce the submerged speed by a larger percentage, even considering the hull design and diesel propulsion.

Interesting. </div></BLOCKQUOTE>

yes - drag on the surface is less... however - most vessels floating on the surface actually waste a lot of forward movement up and down on the waves. Underwater - the direction is clear. So modern submarines travel fast underwater - but not so fast above. 30knots+ submerged and 20 knots or so surfaced.

bertgang
05-20-2005, 09:47 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TheFastFreddie:
I checked on Uboat.net and it said the max speed should be 6kts or the air mask would break off. </div></BLOCKQUOTE>

That was only a part of the problem, as I know.
To have the complete picture, remember that the snorkel is basically a valve to take air near surface.
At high speed it can't work properly, as lot of water spreads income with air; no good at all, for diesel engines.

U-49
05-20-2005, 10:49 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">posted by Bertgang:

At high speed it can't work properly, as lot of water spreads income with air; no good at all, for diesel engines. </div></BLOCKQUOTE>I can see this being an issue in rougher water, or if the boat crept below its ideal snorkel depth. Otherwise the snorkel should've been sufficiently above the waters surface for this not to be a significant issue. Snorkels also used automatic valves to help stop seawater from being ingested into the diesels.

Either way, it seems speeds of greater than 6 knots submerged weren't possible as the snorkel tube itself would break.

bertgang
05-20-2005, 11:34 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by U-49:
Snorkels also used automatic valves to help stop seawater from being ingested into the diesels. </div></BLOCKQUOTE>

Exactly: so when the valve is shut, to avoid incoming water, the diesel can't have the needed external air; very unpleasant.

U-49
05-20-2005, 11:44 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">posted by Bertgang:

Exactly: so when the valve is shut, to avoid incoming water, the diesel can't have the needed external air; very unpleasant. </div></BLOCKQUOTE>Unpleasant for the crew as well as the diesels. I read that when this automatic valve would slam shut, the diesels would briefly draw air from within the sub itself before they shut dow. Apparently a rather unpleasant deafening affair for the crews' ears - sometimes their eardrums would even rupture.

Ouch. http://forums.ubi.com/images/smilies/blink.gif

I'm glad the devs chose not to model this sound in the sim.

archer49d
05-20-2005, 11:57 AM
Inability to exceed a certain speed was modeled in SH2.

SH3 didn't do it. It's a huge mistake.

U-49
05-20-2005, 12:00 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">posted by archer49d:

Inability to exceed a certain speed was modeled in SH2. SH3 didn't do it. It's a huge mistake. </div></BLOCKQUOTE>If a speed around 6 knots is in fact accurate, it's a significant oversight. It would be similar to allowing a type VII boat to travel at 42 knots surfaced.

Slingn
05-20-2005, 12:26 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ShinyBaldy:

yes - drag on the surface is less... however - most vessels floating on the surface actually waste a lot of forward movement up and down on the waves. Underwater - the direction is clear. So modern submarines travel fast underwater - but not so fast above. 30knots+ submerged and 20 knots or so surfaced. </div></BLOCKQUOTE>

You would be stunned to know how fast modern attack subs can go under water. Put it this way, they could get a speeding ticket on most US interstate hwys.

archer49d
05-20-2005, 12:28 PM
Or run into a mountain.

WereSnowleopard
05-20-2005, 01:39 PM
If go flank then may spot easy by enemy due to high spray in air.

twistedpretzel
05-20-2005, 03:12 PM
Wanna know something real interesting?

The snorkels were impractical and hardley used.

sc1949
05-20-2005, 05:24 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by U-49:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">posted by Bertgang:

Exactly: so when the valve is shut, to avoid incoming water, the diesel can't have the needed external air; very unpleasant. </div></BLOCKQUOTE>Unpleasant for the crew as well as the diesels. I read that when this automatic valve would slam shut, the diesels would briefly draw air from within the sub itself before they shut dow. Apparently a rather unpleasant deafening affair for the crews' ears - sometimes their eardrums would even rupture.

Ouch. http://forums.ubi.com/images/smilies/blink.gif

I'm glad the devs chose not to model this sound in the sim. </div></BLOCKQUOTE>

They did! But only for the Sonarman, everyone else's ears are OK.

twistedpretzel
05-20-2005, 07:38 PM
http://www.naval-technology.com/projects/la/specs.html

http://www.naval-technology.com/projects/seawolf/specs.html

http://www.naval-technology.com/projects/ohio/specs.html


In all reality, there hasnt been much of an advance in speed since the early days, however, the amount of sound made at these speeds has been greatly reduced.

OneEight
05-20-2005, 07:51 PM
Since where tlaking about snorkel , i have a question : the snorkel is available on the VIIC VIIC/41 right ? but when i try to buy it , it doesn't show up the " Are you sure " box.
Is this normal ? im in Decmeber 1943

archer49d
05-20-2005, 07:54 PM
It's protecting you against buying something you don't want, it happens with all upgrades.

archer49d
05-20-2005, 10:41 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by twistedpretzel:
http://www.naval-technology.com/projects/la/specs.html

http://www.naval-technology.com/projects/seawolf/specs.html

http://www.naval-technology.com/projects/ohio/specs.html


In all reality, there hasnt been much of an advance in speed since the early days, however, the amount of sound made at these speeds has been greatly reduced. </div></BLOCKQUOTE>

Remember, those are "public" speeds.

S VIIC_41
05-21-2005, 04:53 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">It's protecting you against buying something you don't want, it happens with all upgrades. </div></BLOCKQUOTE>

He says it DOESN'T show the "Are You Sure?" box.

archer49d
05-21-2005, 07:59 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by S VIIC_41:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">It's protecting you against buying something you don't want, it happens with all upgrades. </div></BLOCKQUOTE>

He says it DOESN'T show the "Are You Sure?" box. </div></BLOCKQUOTE>

My mistake, sorry.