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-   Silent Hunter III (https://www.subsim.com/radioroom/forumdisplay.php?f=182)
-   -   2 escorts have me at 170m below. Will it ever end? (https://www.subsim.com/radioroom/showthread.php?t=88207)

HundertzehnGustav 01-11-06 07:25 AM

Quote:

Originally Posted by The Avon Lady
I would never give a trawler the honor of being called a corvette. :nope:

:D

ROGER THAT Mam :nope: ;)

The Avon Lady 01-11-06 07:32 AM

Quote:

Originally Posted by kiwi_2005
What i do in situations like this is go to silent running and then using the dial make speed to 1 or 2 knots cos silent running is only 3 knots and i find i still get detected weather its the radar pinging of my boat i dont know but setting the speed to 1-2 knts then upping the time frame i can get away - never go over 16x time compression though or your history.

I have been trying to evade at 1kt. No go. :nope:

GT182 01-11-06 10:20 AM

AVL try this as Markimov suggested:


Then all you have to do is change the numerical values for these:
LostContactTimeLower=15
LostContactTimeUpper=45


For instance, these are my values:
LostContactTimeLower=5
LostContactTimeUpper=7

I did it lastnight but only changed to 9 for lower and 20 for upper. Works so far but lower might be a bit better. After 20 minutes of some hair raizing DCs the Corvette chasing me finally sailed of to rejoin the convoy. Now waiting for 6 hours to let the crew calm down to surface and do repairs, and convoy to sail on so I can sink that T2 I left sitting dead in the water.

Redwine 01-11-06 10:20 AM

Re: Thermal layers?
 
Quote:

Originally Posted by GOZO
Hi Lady. I think thermal layers were modelled into SHIII? After playing SC for long time I learned the use of sound "bending" in water is very useful. As af few have pointed out, going more shallow and increasing distance may fix it since your sub can be in a "shadow". I have tried this before and it does work. Hanging around at great depth all the time makes it easier for the enemy to find you by "passive" senors. Of course when the go "active" and start pinging you rely on their accuracy in aiming the ASDIC-transmitter. Keeping a small area of your sub (preferrebly the stern) against the transmitter decreases his ability to recieve an echo strong enough to detect you.

Hope it helps. /Per :P

Sadly...after too much look into the files, i need to finish thinking thermal layers are not modelled in SH3.

That was one of the reasons i change the sonnar beams angles into my settings, this modification "simulates" a certain kind of shadow zone when you go depth, a certain kind of thermal layer effect.


The other is because real beams are not simulated in the game, the game only have 2 kind of beams, one for pasive and one for active and no more, and the beams are exagerate wide.

If you look into the long topic of 31 pages you will find this, look the graphic posted by gouldjg :

Page 9 :

http://subsim.com/phpBB/viewtopic.ph...rops&start=200

The beams was very narrow.

In the game, sensors has wide beams, in example pasive and active sensors has a contant detection angle from surface down to 90 degrees down.
Due to that they can detect you even when they are just passing over you, and they can detect you full turn maneuvers even if they are over you. I changed that.

In the game, they are able to detect you even at silent running, when they arte far.

That was not real, a sub sailing at silent running was near to undetectable.

Even in modern wars it is true for electric subs, which prove to be realy hard to detect at silent running even by more modern sensors than those of WW2.

Into that topic you can found interesting information about that :

Page 2 :

http://subsim.com/phpBB/viewtopic.ph...drops&start=25

Posted by Caspofungin from real life reports :

here's some more info re hydrophones:

"ADM 219/563, Theoretical U/Boat listening ranges. This report was published by the US Navy's 10th Fleet ASW OR Group on 20 Aug 1943. Neglecting reflection and reflection of sound, and considering attenuation only, the distances at which a U-boat could detect the hydrophone effect (HE) for the noise output from a 50-ship convoy, or detect pings from a 40-watt QC projector, are given, in yards, as:

Water noise level-----Hydrophone Effect-----Intercepting pings
High---------------------------7,000----------------------19,000
Medium---------------------21,000-----------------------25,000
Low--------------------------31,000-----------------------27,000

These figures are viewed as reasonable, as U-boat survivor reports claim ranges of 10-15 miles, and in one case 20 miles.
Using sound intensities typical for US submarines, the following distances in yards at which an escort can hear a U-boat travelling at different speeds are calculated using similar assumptions:

Water--------------------Surfaced--------------------Submerged
Noise----------------7kt---14kt---17kt---------------4kt---6kt
High-----------------50---500---600------------------50---750
Medium-----------260---1800---2100--------------260---2500
Low---------------430---2500---2900----------------430---3300

It is assumed that the listening is non-directional and that the ASW vessel is noiseless. It is further assumed that these unrealistic assumptions will probably cancel each other out in practice."

The above is from
http://www.google.com/search?q=cache...n&client=opera

which also has interesting info re number of torps needed to sink a ship, but that's a different discussion.

check the last table, the bold number -- that's surprisingly low range for a sub at (i assume) silent running. is that reflected in sh3?

also QCL, QCE, QGA are American active sonar systems.



As you can see in a noise water, it may be heavy waves or DD's high speeds, a sub in surface at 7 knots can be detected only at 50 yards, and submerged at 4 knots at 50 yards (45m)

With medium noise water submerged at 4 knots, it can be detected only at 260 yards, 234m.

I magine at silent running and 1 or 2 knots......

Due to that, and many comments i read along the time in many fonts i serach for a good silent running.


I my settings i look for a good and effective silent running, and for reduced sensor beam angles to reduce DDs/DEs effectivity, it give a certain protection when depth, not a thermal layer simulation but is better than nothing.

:up:

svenks 01-11-06 10:37 AM

Quote:

I'm not overly surprised that a "Copy of sensors.dat" file would be chosen over a "sensors.dat" file if both resided in the same folder.

Neither am I, but it all depends on how the program reads the folder contents. On the other hand, changing the extension almost always works, e.g. rename sensors.dat to sensors.tad.

Avon, if possible get both escorts to one side of you, turn your bow or stern (no, your sub's of course :lol: ) towards them. Active sonar is much less effective when it bounces of a small target.
Or you could go as deep as you possibly can and stop engines. Then see what happens.
Hope you get out of this mess,
BRGDS
Sven

MirabelleBenou 01-11-06 10:44 AM

Redwine > the links you post send me only to the index page of the forum.

Strange things.....

Redwine 01-11-06 10:47 AM

Quote:

Originally Posted by svenks

Avon, if possible get both escorts to one side of you, turn your bow or stern (no, your sub's of course :lol: ) towards them. Active sonar is much less effective when it bounces of a small target.
Or you could go as deep as you possibly can and stop engines. Then see what happens.
Hope you get out of this mess,
BRGDS
Sven

In that long "investigation" we noted in the AI sensrs file there is no present a line for aspect factor......

But it is present in another places, then i add a line for aspect factor in my settings, i am not sure if it works or not, but it is there stand by.

May be the game pick up it, because i note is is more easy for me to scape when i maintain the red lines of sonar contacts in the map always at my back.......

Redwine 01-11-06 10:49 AM

Quote:

Originally Posted by MirabelleBenou
Redwine > the links you post send me only to the index page of the forum.

Strange things.....

:hmm: :hmm: not for me..... but i will edit the post with the page number for you :up: :up:

They are page 9 and 2

MirabelleBenou 01-11-06 11:20 AM

found them, thanks :)

kiwi_2005 01-11-06 12:31 PM

Quote:

I have been trying to evade at 1kt. No go.
This works about 3 out 5 goes, so save. Go as deep as you can then go to flank speed :huh: Yup. as soon as you think the escorts are above you while at flank speed head to the surface , if you time it right you wont get hit cos the charges are set to approx the depth you were at, zigzag while heading to the surface heading in the opposite driection to the escorts. Once you reach around 40 go all slow, cut to silent running and 2 knts, stay at around 40. If your feeling really game go to persicope depth and fire some quick wild shots just to get them really annoyed then do a little evil laughter to yourself and head back to 40-50 feet.

I call it the Krazy Kiwi move. :lol:

kiwi_2005 01-11-06 01:25 PM

Is this a waw patrol? If so then maybe the Krazy Kiwi move might not be a good idea, if everything went wrong you dont want to get sunk.

The Avon Lady 01-11-06 03:38 PM

Quote:

Originally Posted by kiwi_2005
Is this a waw patrol?

:yep: :yep: :yep:
:oops: :oops: :oops:

Hartmann 01-11-06 06:04 PM

They are doing like trully hunters killers... and want drain the battery or the O2 of the boat until it was forced to surface. or stay forever underwater :dead: :dead:

If they don´t return to home the only option is wait to the night and run or fight in surface. :dead:

Or show the periscope near of a DD, with some luck Perhaps they blow up each other with the guns. :88)


In a diesel submarine with all of movile parts like turbines, ventilation, compressors and pumps shut off, coul be almost undetectable at 0 knts with pasive systems.

the question is how many things need to run a WW2 submarine, i think that a very few...perhaps ventilation fans and no more.
the only noise could be the hull in the surface waves or depht pressure effects.

In the later war the only hope was the new XXI sub , with great underwater endurance, speed, and snorchel.

Today the AIP in the modern diesel subs and radar coating snorchels make they a very dangerous oponent despite the advanced ASW gears and tactics.

GOZO 01-12-06 05:36 AM

This is really a healthy forum and an intressting topic. So for what I have learned sofar my only hope for Avon is if you have decoy launchers and Albereich coating on your sub. Decoys have saved my butt several times when caught in shallow waters.

:up: /Per

Redwine 01-12-06 07:44 AM

Quote:

Originally Posted by Hartmann
They are doing like trully hunters killers... and want drain the battery or the O2 of the boat until it was forced to surface. or stay forever underwater :dead: :dead:

If they don´t return to home the only option is wait to the night and run or fight in surface. :dead: .


That can be controled well with :

[AI detection]
Lost contact time=15 ;[min]

Reducing this time, they return to escort position often.

This time is the time during wich one if the DD or DE do not have contact with you, it abandon the search for you and return to escort position.

Will be good i we can have both behaviours, a DDs hunter killer serching for you up to you remain without battery and O2.

And a DE wich search for you few minutes, enforce you to dive deep, and back to escort position.

CB commented it is posible, but i was unable to understand understand him about how to do it.

:up:


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