Hydrophone at periscope depth

hachiman · 03-21-07, 08:48 AM

Hi

Heard some reports the hydrophone does'nt work at peri depth'but a few metres below this

Is this true??

swe-mike · 03-21-07, 10:12 AM

Yes that is correct. I'm not a 100% sure about the exact depth figure but from what I heard you have to be at/or below 20 meters for it to operate.

Can some1 confirm 20 meters?

Regards,

Mike

Spaxspore · 03-21-07, 10:23 AM

Quote:

Originally Posted by swe-mike

Yes that is correct. I'm not a 100% sure about the exact depth figure but from what I heard you have to be at/or below 20 meters for it to operate.

Can some1 confirm 20 meters?

Regards,

Mike

i can confirm, played 4 patrols and not once got a audio contact at anything above 20m

Onkel Neal · 03-21-07, 10:27 AM

17 meters. Soon to be 55 feet.

castorp345 · 03-21-07, 10:31 AM

Quote:

Originally Posted by Neal Stevens

17 meters. Soon to be 55 feet.

"soon"??

any word you can divulge as to what the timeframe on that "soon" might be???

ssbn627g · 03-21-07, 10:33 AM

Quote:

Originally Posted by Neal Stevens

17 meters. Soon to be 55 feet.

I don't ever remember giving the order:

"Dive, make your depth .... meters" LOL!

Onkel Neal · 03-21-07, 10:34 AM

Really, truly soon

Nightmare · 03-21-07, 11:09 AM

Shouldn't sonar work at periscope depth though? At least to a degree? The sonarman would always call out "Running hot, straight, and normal" after torpedoes were fired during an attack run. Since in real life, a sonarman would hear the torpedoes and make sure they were running normally, I would think that sonar would function to a degree.

hachiman · 03-21-07, 12:01 PM

So is'nt that a bug?
You could listen at PD in SH3!!

NefariousKoel · 03-21-07, 12:53 PM

Quote:

Originally Posted by hachiman

So is'nt that a bug?
You could listen at PD in SH3!!

Since you could do it in SH3, I'm guessing this will be easily modified in SH4 to whatever depth.

I'm not sure where the hydrophones were located. If they were on the deck, then it certainly wouldn't make sense being able to use them while surfaced if they're above water or at the waterline.

HannesGM · 03-21-07, 04:08 PM

I've read that escorts had problems with sonar at steep angles early in the war... but too shallow??? Never heard of... If anything, you shoudnæt be able to hear a ship passing over you on sonar.

But yeah, sonar here works also just when passing below 17m.

Charos · 03-21-07, 05:12 PM

Quote:

Originally Posted by Neal Stevens

17 meters. Soon to be 55 feet.

Incorrect

Planesman make depth - 55.7742783 Feet.

Snowman999 · 03-21-07, 05:25 PM

Quote:

Originally Posted by Nightmare

Shouldn't sonar work at periscope depth though? At least to a degree? The sonarman would always call out "Running hot, straight, and normal" after torpedoes were fired during an attack run. Since in real life, a sonarman would hear the torpedoes and make sure they were running normally, I would think that sonar would function to a degree.

Sonar should work at PD, yes. I'd have to look at plans, but I think later fleet boats had primary sound heads on the underside of the superstructure. The late-war FM sonar I think had them topside.

I've seen game reports of enemy ships passing at 400 yards and sonar not hearing them. This is just wrong--you can hear a skimmer at 400 yards with your ears while standing in the middle of Control. With a Dixie cup on the hull you could hear the skimmer's CO ask for more coffee. I think this isn't modeled correctly.

PeriscopeDepth · 03-21-07, 05:45 PM

I would think early sonar would be pretty degraded at PD due to surface noise. For best performance, I would think you'd need to be below PD. I bet the SH engine can't handle that, so it's below PD or nothing.

PD

Snowman999 · 03-21-07, 08:41 PM

Quote:

Originally Posted by PeriscopeDepth

I would think early sonar would be pretty degraded at PD due to surface noise. For best performance, I would think you'd need to be below PD. I bet the SH engine can't handle that, so it's below PD or nothing.

PD

See http://www.maritime.org/fleetsub/sonar/index.htm for everything you'll ever want to know about WWII sub sonar ops. Clearly it worked at PD as turn-counts were the primary speed-determining method fed to the TDC. Not to mention dozens of printed accounts, both real and fictional.

Surface noise in the sound channel is a challenge, yes, but fleet boats had dual sound heads on the keel, not topside. 55+ feet below the surface. Not hearing a maneuvering surface contact at 400 yards is impossible.

03-21-07, 08:48 AM	#1
hachiman Planesman Join Date: Dec 2001 Location: Edinburgh Jockland Posts: 199 Downloads: 33 Uploads: 0	Hydrophone at periscope depth Hi Heard some reports the hydrophone does'nt work at peri depth'but a few metres below this Is this true?? __________________ Whats not to love about Submarines? Long'Hard and full of Seamen!!

03-21-07, 12:01 PM	#9
hachiman Planesman Join Date: Dec 2001 Location: Edinburgh Jockland Posts: 199 Downloads: 33 Uploads: 0	So is'nt that a bug? You could listen at PD in SH3!! __________________ Whats not to love about Submarines? Long'Hard and full of Seamen!!

03-21-07, 10:12 AM	#2
swe-mike Nub Join Date: Mar 2007 Location: Sweden Posts: 4 Downloads: 0 Uploads: 0	Yes that is correct. I'm not a 100% sure about the exact depth figure but from what I heard you have to be at/or below 20 meters for it to operate. Can some1 confirm 20 meters? Regards, Mike

03-21-07, 10:27 AM	#4
Onkel Neal Born to Run Silent Join Date: Jan 1997 Location: Cougar Trap, Texas Posts: 21,383 Downloads: 541 Uploads: 224	17 meters. Soon to be 55 feet.

03-21-07, 10:34 AM	#7
Onkel Neal Born to Run Silent Join Date: Jan 1997 Location: Cougar Trap, Texas Posts: 21,383 Downloads: 541 Uploads: 224	Really, truly soon

03-21-07, 11:09 AM	#8
Nightmare Engineer Join Date: Nov 2003 Location: Portland, OR Posts: 210 Downloads: 10 Uploads: 0	Shouldn't sonar work at periscope depth though? At least to a degree? The sonarman would always call out "Running hot, straight, and normal" after torpedoes were fired during an attack run. Since in real life, a sonarman would hear the torpedoes and make sure they were running normally, I would think that sonar would function to a degree.

03-21-07, 04:08 PM	#11
HannesGM Watch Join Date: Mar 2007 Posts: 30 Downloads: 8 Uploads: 0	I've read that escorts had problems with sonar at steep angles early in the war... but too shallow??? Never heard of... If anything, you shoudnæt be able to hear a ship passing over you on sonar. But yeah, sonar here works also just when passing below 17m.

03-21-07, 05:45 PM	#14
PeriscopeDepth Sea Lord Join Date: Jul 2002 Location: Pacific NW Posts: 1,894 Downloads: 6 Uploads: 0	I would think early sonar would be pretty degraded at PD due to surface noise. For best performance, I would think you'd need to be below PD. I bet the SH engine can't handle that, so it's below PD or nothing. PD