How the hell did this happen??

[CaptainNemo12]

I was approaching a convoy head on at periscope depth at ahead slow, silent running, with the leading frigate approaching at about 8000m - 9000m off my bow. Decided to dive to 40m and ordered all engines stop. At this point the frigate is about 20 degrees off my starboard bow.

After a few minutes, my boat was dead in the water and not making a sound. As I watched through the external camera, the leading frigate continued on its course for another 5 mins as if it no one was there. Suddenly, at about a 1000m away from my U-boat, the damn thing veered off course and started pinging away at me!

How this this happen? I thought that warships only started pinging after they had detected propeller noises? How could they detect an object underwater that is not making a single sound?

I'm playing GWX 3 and this is not the first time this had happened, I once tried to pass below the keel of a merchant at about 50m underwater when the merchant somehow detected me (underwater!) and turned to avoid...

Any ideas?

[KL-alfman]

1) what date?
2) escorts in late war "ping" constantly
3) 1,000m is very close (should've been 2-2,500m)

and fourth and most important:

sink em all! :up:

[Jimbuna]

2) escorts in late war "ping" constantly


In GWX3.0 even? :hmmm:

[CaptainNemo12]

Currently in 1940, any other ideas? Could this be to due to surface units having "underwater" sensor data in GWX?

[Vipper]

Happened to me too at very early 40 and not only to me. There is other threads complaining that DD's have "psychic powers". Some messages claimed that this is known glitch that when sub presents excellent sonar target cause angle and DD is near by it does start to ping.

So, maybe they really have "psychic" powers.

Some peoples told that DD's that were mess with before stays alerted state and may ping randomly.

Who knows?

[Jimbuna]

In GWX the escort is nearly always in a passive state/mode.

If their sensors alert them to your presence in the area they then go into active/pinging mode.

[CaptainNemo12]

Thanks Jim for clarifying, so I'm guessing the DD's so "sense" a sub submerged with engines off? I don't really see how this is realistic since I did not hear any random pings when approaching the convoy in the first place...:hmmm:

[Dutch]

Might have come across an elite Jedi filled DE. I do agree with you were a bit close you do generally want to be around 2k away and then move in once they have you in their wake.

[pickinthebanjo]

Thanks Jim for clarifying, so I'm guessing the DD's so "sense" a sub submerged with engines off? I don't really see how this is realistic since I did not hear any random pings when approaching the convoy in the first place...:hmmm:

http://img232.imageshack.us/img232/569/79761231.png
I get ahead of convoys and cut my engines all the time (every time) and not once has a single destroyer started searching for me until after I fire some torpedoes. Heres a pic just to show that you can be right beside enemy destroyers and they will have no idea your even there.
By the way I use SH3 with GWX3, Commander and that OLC GUI(Still learning that one)

Oh yeah also I play on 95% Realism (only external cam is enabled, and recently stabilized view)

[CaptainNemo12]

That is very strange indeed, would it be best to approach the convoy head on submerged from a 45 degree angle off the lead DD's bow?

Has anyone come up with a fix for this bug? Big realism killer IMHO.

[HW3]

I managed to slip into a convoy in March 44 guarded by 15 escorts from the front head on passing the lead escort at about 1000M. I was at periscope depth, silent running, and engines stopped. Admitted this is a very rare occurrence and I was in a type IXC. BTW I sank 2 ships and got away. The only thought I have is if the sea was rough, maybe your conning tower broke the surface and was spotted?

[KL-alfman]

In GWX3.0 even? :hmmm:


you might be right.
I was confused by ryanglavin's story about the procedures DDs usually did .....

[CaptainNemo12]

maybe your conning tower broke the surface and was spotted?

Impossible, by the time the DDs were within visual range, I was 40m beneath the waves:yep:

[PappyCain]

Not sure if I understand this:

How could they detect an object underwater that is not making a single sound?

The concept is to ping or send a sound wave out and if it hits an object and bounces back then it is clear there is a object that requires additional investigation. Point is the sonar operator does not have to 'hear' your screws to ping.

I can only suspect that the angle of your sub to the vessel presented a good 'return' on the sound wave and he swung back to search and confirm.

Also "head-on" usually means nose to nose. Are you saying you approached head on? Bow to bow, or off his port or starboard quarter, or abeam?

I suppose the programmers have the answer BUT I do not want to know as that is an immersion killer for me!!! LOL I rather would like to think there are really lil' people in the game who make the decisions. ahahhaha.



S'

[Jimbuna]

The game imposes upon us a sense of parameters that we'll probably never fully understand.

Keep as low a cross-sectional profile to the escorts and maintain a depth that allows no margin of 'porpoise' level and that should minimize your chances of being detected.

Rest assured, once you have given the enemy a 'sniff' of your presence, every tool in his arsenal will be activated to bring about your demise.

[CaptainNemo12]

I was approaching the DD head on at a distance of about 8000-9000m, by the time the DD was within 1000-1500m of me I was about 20 degrees off the DD's starboard bow, at 40m, engines stopped. What I don't understand is that I did not hear any "pinging" sound coming at me until after the DD somehow found me underwater. Do the DDs use some sort of inaudible sonar to detect objects underwater and switch to ASDIC when they detect such an object?

[Snestorm]

Shot in the dark.
Could SH3 be using ASPECT for hydrophone contacts, instead of SOUND???

[pickinthebanjo]

Now I'm confused. I've hit at least 4 convoys on my career, this is my second career by the way. And in each of those attacks I've cut the convoy off and got in it's path way outside visual range. Then I cut engines and wait. When the convoy is passing over me the I attack.

But it seems that most people are detected when they should not be, hmm.
I don't understand why I don't have this problem, Your all using GWX3 and commander?

[CaptainNemo12]

Your all using GWX3 and commander?

I am!:DL

[pickinthebanjo]

I am!:DL

Well this is totaly off topic but if you want convoy like tonnage, attack Scapa Flow. I'm going to be posting a totorial on the best way to do so as soon as I finish the attack I'm about to commence right now. (need Some Pics First)

I attack that harbor every 6-12 months

[Snestorm]

Now I'm confused. I've hit at least 4 convoys on my career, this is my second career by the way. And in each of those attacks I've cut the convoy off and got in it's path way outside visual range. Then I cut engines and wait. When the convoy is passing over me the I attack.

But it seems that most people are detected when they should not be, hmm.
I don't understand why I don't have this problem, Your all using GWX3 and commander?

I don't have this problem. Just trying to figure out a reason, for those that do.
(And I never cut my engines off. Always 90 RPM.)

[pickinthebanjo]

I don't have this problem. Just trying to figure out a reason, for those that do.
(And I never cut my engines off. Always 90 RPM.)
They Don't Hear You? Ill Have To Incorperate That into my attacks, It's so hard to try and line up just right outside visual range in front of the convoy with no engines.

[unterseemann]

Hello, first i think there is no point in diving to 40m ( look at GWX manual B15 and B16 appendix), keep periscop depth and don't show your periscop. You don't have to wait at 0kn you can keep a speed of 1-2 knots while approaching the convoy, so you can move out of the escorts path
Also another thing, i may be wrong but... it seems that external camera attracts escorts' attention so stay in your boat, rely on hydrophon and check with your periscop when visual contact is possible to adjust course
Hope it will help you!

[Mittelwaechter]

Why do we expect the DDs to use only passive hydrophone while running a search pattern?

Me as a DD captain I would have ordered to run an active ASDIC search just right into the blue from time to time.

I think it is quite realistic to be pinged occasionally sitting close to a DD on duty. Keep your aspect low and hope you'll make it into the convoy.

In later war I stay outside the convoy and make full use of my pattern running torpedo stand off capabilities. :DL

[bigboywooly]

For some reason at PD you are less likely to be picked up than at 40m
Have no idea why
If seas are rough I will go to 20m and seems ok

[sergei]

For some reason at PD you are less likely to be picked up than at 40m

Surface clutter?
I'd be surprised if the game actually modeled this though.

[codmander]

u-r- unlucky :arrgh!:

[bigboywooly]

Surface clutter?
I'd be surprised if the game actually modeled this though.

No I doubt the game models that :hmmm:
May have something to do with the asdics forward view which IIRC is like a cone that projects ahead of the unit but starts at a certain depth so PD usually gets missed
Still shouldnt be picked up at 40m silent running though in reality unless just unlucky

[Hitman]

Why do we expect the DDs to use only passive hydrophone while running a search pattern?

Me as a DD captain I would have ordered to run an active ASDIC search just right into the blue from time to time.

Because a sonar ping can be heard from huge distances, and convoy smoke not so much. Pinging constantly is essentially like yelling out who and where you are :DL

In real life convoy escorts would only ping when believing or knowing that a Uboat was nearby.

No I doubt the game models that :hmmm:
May have something to do with the asdics forward view which IIRC is like a cone that projects ahead of the unit but starts at a certain depth so PD usually gets missed
Still shouldnt be picked up at 40m silent running though in reality unless just unlucky

Yes in real life the ASDIC beam starts from the lower part of the Escort bow and then goes slightly downward, to ensure the impulse does not hit the surface (Which causes it to rebounce and produce false echoes and cluttering noise). In SH3, since the node is also in the lower part of the hull, it won't detect things that are higher than that unless the geometry is tweaked to allow it -which I don't think it is, and would be irrealistic in any case-. An Uboat can, and shall be detected at peri depth by ASDIC as long as it is deeper than the sonar dome in the escort and close enough. Otherwise, the beam goes downwards and can't reach her to get a meaningful echo.

In any case, I also have suffered the easy detection many times, and I'm pretty sure it was passive hydrophone what got me. May be ocasionally on day time the periscope, but mostly the passive sonar. Though I must say that I never cut engines completely as it is irrealistic -U-boats in reality were never perfectly trimmed and needed 2 knots at least to keep constant depth.