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-   -   Passing thermal layer and DC's attack? (https://www.subsim.com/radioroom/showthread.php?t=108840)

NEON DEON 03-28-07 11:47 PM

Quote:

Originally Posted by Steeltrap
The escorts will use the tracks of your torps to estimate your position when you fired them and attack that area fairly immediately. I'm guessing that's what you saw.

I've noticed the depth changing abilities of the subs seem to be grossly inflated. Would take well over half an hour for a US sub to get back to periscope depth from around 300' under usual circumstances (pretty sure that's what Dick O'Kane says in Wahoo).

As for being able to control your depth like that while stationary, that's just nonsense.

Lets see.

300 - 60 = 240

240 / 30 = 8

8 feet a minute rise?

I dont think he was trying very hard.;) ;) ;)

NefariousKoel 03-29-07 12:03 AM

Quote:

Originally Posted by NEON DEON
Quote:

Originally Posted by Steeltrap
The escorts will use the tracks of your torps to estimate your position when you fired them and attack that area fairly immediately. I'm guessing that's what you saw.

I've noticed the depth changing abilities of the subs seem to be grossly inflated. Would take well over half an hour for a US sub to get back to periscope depth from around 300' under usual circumstances (pretty sure that's what Dick O'Kane says in Wahoo).

As for being able to control your depth like that while stationary, that's just nonsense.

Lets see.

300 - 60 = 240

240 / 30 = 8

8 feet a minute rise?

I dont think he was trying very hard.;) ;) ;)

LOL.

In Steeltrap's defense he probably read 'seemed like 30 minutes' as "it took 30 minutes."

That's what paraphrasing gets you.

E.Hartmann 04-04-07 11:09 AM

How do I go deeper than the 165'. (Besides having a hole in my boat!! :rotfl: )

Floyd 04-04-07 11:19 AM

Quote:

Originally Posted by E.Hartmann
How do I go deeper than the 165'. (Besides having a hole in my boat!! :rotfl: )

Click below the depth gauge to get the second, larger scale.

Ayari 04-04-07 12:58 PM

Quote:

Originally Posted by HannesGM
Yes, they run out, eventually. Either that, or the crew had their lunch break coming up :D

I also noticed that in SH3 - only occasionally - that the DDs seemed to run out of DCs - they'd still circle over my position, but never throw any more DCs. This was after several hours - literal hours - spent with 4 DDs overhead...

I have seen them run out of hedgehogs in SH3 also

walsh2509 04-04-07 02:19 PM

Can anyone tell me if the devs have modeled the Japanese DC's on historic data, the japanese only set there DC's to 100ft until a Congressman May let it slip that the Japanese were not having much luck with there hunting of US subs as there DC's were set to low. This was printed in a few newspapers and the japanese got to hear about it and started to set there DC's deeper AFTER mid 43.

So if this is modeled correctly then no japanese DC should go deeper than 100ft up until mid43.

JackChen 04-09-07 09:46 AM

There's got to be a smart Jap somewhere who's realising he's not getting any subs.

aurgolo 06-14-07 03:47 AM

Best way to escape a DD
 
I always go for the same tactic since SH3:

1) I run slow at 60 mt or deeper and wait until the destroyer is almost on top of my tail
2) then I ring up flank speed and give hard rudder to port or starboard in order to follow the DD direction
3) In this way I to get out of the kill zone and ask for periscope deph
4) Reduce speed to standard and ask for 0 degrees rudder
5) when at periscope depth I have the DD just in front of the bow at around 3-400 metres and fire a torpedo (perfect shot position)
5) i use this tactic since SH3 and is quite impossible to miss the shot. It works in 95% of cases (according to my experience). I the shot is missied is because the sub gets periscope depth too close to the DD (less than 300 mt) that's why is important to reduce velocity (of course some practice is needed for different sub types according to: ascent rates, submerged speed, etc etc)

Hope it helps

Ciao ciao

andrea

GTHammer 06-14-07 04:25 AM

I read in some other thread that the destroyers have unlimited DC's (or at least they aren't given a set number in the game files)...I think it was redwine that said something about this...I'll look for the thread. Interesting about the 100 ft max thing 'til 43 though...I'll have to make alot of noise down deep and try it out.

Torpex752 06-14-07 06:01 AM

Thermal layers vary, so their ability to hide a sub should & would realistically vary. If the game models that I do not know.
The speed by which a sub changes depth varies as well, there are a number of variables that need to be understood. There is no one speed for changing depth, so in one instance an hour would be fast in another, an hour would be slow. So I am sure Dick OKane was speaking about a specific situation and not the "rule".

:cool:
Frank

vindex 06-14-07 07:11 AM

I go under the thermal layer, run at 1/3, AND rig for silent running. All three are essential ... they can still find you if they know where to look, but it'll be pretty hard for them.

If they are actively pinging you and doing a depth charge run, they know where you are so you better run for it -- briefly, and then go quiet again. Otherwise, remain wery wery quiet.

Cobra_mkII 06-14-07 08:13 AM

Thermallayer is modelled
 
Quote:

Originally Posted by GakunGak
These are two questions:
1. Passing thermal layer makes me invinsible to passive sonar at ahead slow or with silent running? Is it working for real or it is just for show?
2. When under attack by destroyer, what is the best evasion tactic?


Just to prove the layer is modelled-
Flavoured to Taste modified the thermal layer:

"/DATA/CFG/SIM.CFG
------------------------
- ai cannons max fire range from 6K to 9K
- Ai cannons / Max error angle from 3 to 4
- lost contact time from 15 to 30 mins
- visual / enemy surface factor from 400 to 150
- visual / enemy speed factor from 15 to 9
- Visual / light factor from 1.0 to 2.0 (2.0 to 1.75)
- hydrophone / sensitivity from 0.03 to 0.04
- hyrophone / waves factor from 0.5 to 0.95
- hydrophone / noise factor from 1 to 0.35
- hydrophone / thermal layer attun from 3.0 to 2.0
- sonar / detecton time from 20 to 10
- sonar / thermal layer attun from 5.0 to 4.0"

So run silent run deep;)

If I have been detected I run and dive at flank, just before the thermal layer I launch a decoy, switch to silent running and turn away. My flank speed will allow me to drift away from the decoy (which is above the thermal layer) while I creep away below it.

TheSatyr 06-14-07 12:34 PM

I creep beneath the layer. If I get dropped on I go to flank and get out of the way,then start creeping again once the noise from the DCs settle down. I never use decoys since the US subs never had them in WW2...including them in the game is one of my biggest beefs with the game...completely un-historical and un-realistic. (Sort of like having Lancasters with upside down US markings...heh).

Course if I'm caught in shallow water my tactics change. I still creep but I try to keep heading towards deeper water. And when I go to flank when I get dropped on I keep my course heading towards deeper water and hope the DCs drop behind me.

Farinhir 07-09-07 02:05 AM

The reason you become more difficult to detect under a thermal layer is because sound travels at different speeds with different pressure and temps in the water. This along with the cylindrical spreading and signal absorbtion from the layer make it harder to find a sub that is under a thermal layer. There are more factors that would cause this. One is the fact that sound likes to bend in a path that will allow it to move slower. Another is "Ray Propagation Theory". Sound in water can be represented as a vector or ray.

Ray Propagation Theory states that:

1: RAYS will change direction when passing through two mediums of different density. This is Snell's Law. Crossing a thermal layer would count as passing through two mediums of different density.

2: Sound will bend towards the region of slower sound speed.

Because of these factors, when you cross a thermal layer you can find that most of the area is a shadow zone.

A good source of information on this is a powerpoint found on Berkley's navsci area (something I stumbled upon). Most of my information is from there.

Source PPT:
http://navsci.berkeley.edu/ns401/NS4...ound%20mjh.ppt

Read the instructor notes that were included with the slides. They give a lot more info.

CHeers,
~F~

GakunGak 07-09-07 08:56 AM

@Farinhir: THNX for the link, ya rule!!!!!!!:rock:


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