Escort see me without pinging

[RussaX37]

I'm running under water on silent but when I come close to escort like 1000m I'm not stealth anymore and soon after that start pinging.
I tryed to turn off engines but anyway can see me.
Some kind of sonar or what?

The British called it ASDIC (acronym for Anti-Submarine Detection Investigation Committee), the Americans called it sonar. During WW2 it was the main ASW detector against a submerged U-boat of Allied escorts. To evade it, there's a couple of solution:

• Firstly, since it's useless against surfaced U-boats, stay above as long as you can and preferably make attacks on the surface at night (till radar appears.)
• Secondly, if you have to be underwater, try to dive deeper.
• Manoeuvre out of the beam of the escorts, keep your distance and get inside the ASW ship‘s baffles
• Try to minimize your silhouette by keeping the aspect angle close to 0° or 180°.

[RussaX37]

Originally Posted by allievo

The British called it ASDIC (acronym for Anti-Submarine Detection Investigation Committee), the Americans called it sonar. During WW2 it was the main ASW detector against a submerged U-boat of Allied escorts. To evade it, there's a couple of solution:

• Firstly, since it's useless against surfaced U-boats, stay above as long as you can and preferably make attacks on the surface at night (till radar appears.)
• Secondly, if you have to be underwater, try to dive deeper.
• Manoeuvre out of the beam of the escorts, keep your distance and get inside the ASW ship‘s baffles
• Try to minimize your silhouette by keeping the aspect angle close to 0° or 180°.

yeah I was able to manage with keeping some distance and using 0 and 180 angles. this also helping when they are hunting with sonar so I managed to escape once.

Keep in mind that from '42/43 the chances were against the U-boats so historically it's completely accurate being detected and sunk by escorts no matter what you do. In the late war returning to base is considered a success and should be rewarded with the Knight Cross.

[Kielhauler1961]

Originally Posted by allievo

Keep in mind that from '42/43 the chances were against the U-boats so historically it's completely accurate being detected and sunk by escorts no matter what you do. In the late war returning to base is considered a success and should be rewarded with the Knight Cross.

I'd go further and suggest that anyone willingly leaving port after 1942 needs to have their head examined.

I only do it because Doenitz knows where I live. The escort vessel follows us out to make sure we leave...

KH

[u crank]

Originally Posted by Kielhauler1961

I only do it because Doenitz knows where I live. The escort vessel follows us out to make sure we leave...

Very good.

[RussaX37]

Originally Posted by allievo

Keep in mind that from '42/43 the chances were against the U-boats so historically it's completely accurate being detected and sunk by escorts no matter what you do. In the late war returning to base is considered a success and should be rewarded with the Knight Cross.

I'm playing 42/43 because I like to use bigger u boats with some technology torpedos and equipment. Also it's bigger challenge to test your skills. Now I'm hunting one large convoy for the 3rd time.Following that covoy for about 3000 km.
At the beginning was terrible storm and 0 visibility for like 600 km + they were manevouring to make me lose them so I almost lost them 2 times. now I'm done with torpedos and fuel is also very low so I'm returning from good hunting.

[Sailor Steve]

Originally Posted by allievo

The British called it ASDIC (acronym for Anti-Submarine Detection Investigation Committee)...

One of the more interesting anomalies of the war is that the acronym seems to have been made up after the name was given, since there never was any such committee.
http://uboat.net/allies/technical/asdic.htm

...the Americans called it sonar.

Which stands for SOund Navigation And Ranging.

[RussaX37]

Originally Posted by Sailor Steve

One of the more interesting anomalies of the war is that the acronym seems to have been made up after the name was given, since there never was any such committee.
http://uboat.net/allies/technical/asdic.htm



Which stands for SOund Navigation And Ranging.

Seems we have old captain

I think nobody answered the original question which I believe was: How does a destroyer detects u-boat which sits dead silent underwater ? so this situation is very common - if the DD is going just right above you or close enough, he will always detect you somehow and will start pinging, leaving you guesing how did he spot you in the first place ? I'm guessing this has something to do with DD sensors of SH3.

[Riccardo1975]

If I dive to 200m+, ahead 1/3 and set planes to surface my boat kind of skims along without sinking deeper. Above 200m DD's can hear me. Thermocline maybe?

Passive phones on ASW vessels I appreciate but they always seem to be making far too much noise for their soundman to stand a chance of hearing me creaking/RFSR at 25m? ASW trawlers I always find parked between Gib and Tangiers but the real McCoy(Tribal/BlackSwan/J&K)never seem to stop and listen....

Rich

[BigWalleye]

Originally Posted by Riccardo1975

If I dive to 200m+, ahead 1/3 and set planes to surface my boat kind of skims along without sinking deeper. Above 200m DD's can hear me. Thermocline maybe?

Passive phones on ASW vessels I appreciate but they always seem to be making far too much noise for their soundman to stand a chance of hearing me creaking/RFSR at 25m? ASW trawlers I always find parked between Gib and Tangiers but the real McCoy(Tribal/BlackSwan/J&K)never seem to stop and listen....

Rich

Thermal layers are built into SH3 Commander, if you use it. If not, they are not in the stock SH3 AFAIK.

In NYGM, it seems that there is almost always one escort trolling at low speed (or even stopped, the treacherous buggers!) whenever there are 2 or more escorts.

[Riccardo1975]

So which ones right then? Should I be able to do 0 knots at 220m without my pumps running or do i have to have enough revolutions with silent running to maintain my depth and therefore make some noise either way. Ive just done my usual start of patrol depth test to 225m after leaving Thalia (24/21940)and went to All Stop. Didnt sink even on TCx8.

So will I start to sink if I rigged for silent running because of no pumps....?

What are the symbols that appear when you are rfsr? One is no reloading but the other 3?
Its all a learning curve....
Cheers for helping me out chaps?

Riccardo

[Zosimus]

The reality is when you are running silent the pumps still operate. There are merely operated by hand rather than by noisy machinery. It may not be as efficient, but it's a lot quieter.

[BigWalleye]

Originally Posted by Zosimus

The reality is when you are running silent the pumps still operate. There are merely operated by hand rather than by noisy machinery. It may not be as efficient, but it's a lot quieter.

Yes, the pumps could be operated by hand. Everything on the boat except the propulsion could.But do you have a source that says that neutral bouyancy could be maintained indefinitely with hand-operated pumps? And that operating the pumps by hand was silent? Less noisy, sure, but a continuous noise source was all the escorts were listeing for. And sound travels a long way in water.

Does anyone have a published source that says that a WW2 submarine could mainatin constant depth indefinitely without operating electric motor-driven equipment? There are certainly first-person accounts (and technical documents) that indicate they couldn't.