Escorts with ESP?

[AlanSmithee]

It's 1943 and I had pulled into position roughly 8000 meters in front of a very enticing large convoy. I dove to 90m, planning to allow the lead escort to pass over me so I could rise to periscope depth and attack the convoy from within. All was going according to plan, until the lead escort, only a few hundred meters from me, begins to ping me without warning. Suddenly I get the "Depth charges in the water!" call from my sonarman, and seconds later I take an unlucky hit and I'm dead. :shifty: :shifty:

Something just didn't seem right about this. How did the escort know to start pinging me? It certainly didn't detect me before I dove, or it would have come after me then. I also can't think of any obvious noise I made after I dove - silent running, never used the electric motors at all, and wasn't loading any torpedos or making any repairs. If the dive itself made any noise, I had reached 90m long before the escort began to pass over me - and the escorts didn't seem to deviate from their normal search pattern during my dive.

The only possibilities I can conceive of are 1) A stopped, silent u-boat makes a heck of a lot of noise, enough to be heard on escorts' hydophones; or 2) the escorts are also playing on less than 100% realism and are scanning around underwater through the magic of F12. :hmm: Any idea what's going on here?

Edit: I had saved immediately before being detected, and retried this scenario a number of times. I was discovered roughly 2/3 of the time. This also gave me a chance to note that the escort never actually passed over me, but always detected me at roughly the same distance, about 30-40 degrees off his bow.

[_alphaBeta_]

I've seen similar behavior. I was trying to penetrate the inside of a convoy as well sitting at 20M. By a miscalcuation and stupid use of TC I got too close to the lead destroyer and was detected.

Like you I was running silent with zero propulsion.

At first I was angry as well thinking how could they find me if I wasn't moving. Then I thought that the U-Boat is probably still emitting noise even though running on silent. With the destroyer so close, even this small noise is enough to get you detected.

The lead escorts usually favor one side of the convoy's movement. Go to that side and stay way over until the lead destroyer passes. Then head straight in.

[Cdre Gibs]

Its because they can always "See U" in that dotted 180° semi circle shape that u see in front of escorts when u select one on ur nav map. As far as I can tell, at speeds LESS than 10-12knts (depending on escort type), all escorts will sweep that dotted area in front of their ships constantly. We just cant hear it till they are very close and by then its to late. The Escort only needs to ping u 1's in that area and ur busted.

[_alphaBeta_]

Its because they can always "See U" in that dotted 180° semi circle shape that u see in front of escorts when u select one on ur nav map. As far as I can tell, at speeds LESS than 10-12knts (depending on escort type), all escorts will sweep that dotted area in front of their ships constantly. We just cant hear it till they are very close and by then its to late. The Escort only needs to ping u 1's in that area and ur busted.
Well I considered that it may be escorts pinging while running, but I thought this was very dangerous for the convoy. Wouldn't this sound be audible from a great distance giving away the escort (and convoy) position? Realistic or not, I wonder if this is what the in-game destroyers are doing.

[tycho102]

This is something I've been wondering for awhile.

Did escorts use active sonar, constantly, when they were transiting the Atlantic? Did they just use it as part of their sweep, for a minute or so while they were leading the convoy?

I might understand them use un-audible sonar gear on a constant basis. It would generate a lot of wear and tear on the equipment, but less likely to be "heard" from roving uboats.

And then on top of that, there's the elite escorts who always know where you are, no matter what. Haven't come across any of them just yet, but I'll eventually get there.

[Cdre Gibs]

What would u consider to be making more noise. 14 Slow, Old and Loud clanking Merchants chugging along for all they are worth, or the odd ping every now and then from an escort ?

A deep constant thumping can be heard a very long way off, so whats a few pings here or there ! :)

[chaos]

sound travels further and louder through water thats why with todays sonar you can tell what kind of ship is making the noise from over 20 miles away

[Wulfmann]

Alan, it would help by posting what your install and mods are.
In 1943 the change to 3 crew ratings is in place and the 4 rating on some in 43 in the stock SH3 is an almost sure kill.
The sonar and AI fix in RUB is very important in reducing this to realistic levels.
While, yes, RUB makes things more difficult in some ways, it corrects inaccuracies in others that make it easier, as it would have been, not for easy sake.

Wulfmann

[AlanSmithee]

Thanks for the responses, guys. Love this forum! :up:

A little bit of searching over at uboat.net may have solved my problem. Disscussion on their tech forum (http://www.uboat.net/forum/read.php?f=20&i=4869&t=4867&v=f) seems to suggest that the most common tactic used by escort screens was to ping away with ASDIC almost constantly. Note this in particular, from a Mr. Ron C:

"I was navigator (and tactician) of a frigate in Captain Walkers EG2 and the usual search method was by Asdic -- presumably because the hydrophone was not capable of detecting the type VII at a greater range than asdic could unless the boat exceeded say 5kts. ... Re asdic operation, the ping went on 24/7 and was relayed onto the bridge loud speaker. Altho' one ceased to hear the continuous ping after a while, any change in the doppler of the reverbs or a return echo broke the "silence" and alerted the whole brdge team before the asdic operator reported."

Obviously this wasn't convoy escort he's talking about, though it's still pretty good evidence that ASDIC was used constantly. Other cited material suggests that convoy escorts relied mosly on active sonar, but would ocassionally use passive detection.

I feel more satisfied now. Not cheated, but still dead. :dead:

[FAdmiral]

If you watch the escorts closely, you will see them turn and
change speeds very often. When they slow to 5 or so kts,
they listen and then use sonar pings, they will then speed up,
change course and do it again. I find if they come with 1500
meters of you (no matter where you are & what you are doing)
you W*I*L*L get pinged. Once that happens, you had better get
out of dodge ASAP.....


JIM


PS. Happened to me ONCE, then I learned NOT to repeat the
mistake....

[chaos]

also noticed that the escorts whilest not picked you up on sonar ( running silent at 3kts) shadowing the convoy your sound indicator is green as soon as you open a torpedo tube they all of a sudden start to make defencive zig zags and go on the offencive actively pinging :roll:

[AlanSmithee]

If you watch the escorts closely, you will see them turn and
change speeds very often. When they slow to 5 or so kts,
they listen and then use sonar pings, they will then speed up,
change course and do it again. I find if they come with 1500
meters of you (no matter where you are & what you are doing)
you W*I*L*L get pinged. Once that happens, you had better get
out of dodge ASAP.....

That's basically my experience too, though there seems to be some randomness to the escorts' pinging. Perhaps escorts are switching back and forth between active and passive sonar, and I just got lucky on some occasions. Still, it's not a bet worth taking.

[_alphaBeta_]

Well that would explain why getting close to them is such a problem.

I remember I was within a few hundred meters one time during another early career. The stealth meter changed a couple of levels, but nothing else happened. It was probably too early for ASDIC or that destroyer didn't have it.

[DirtyHarry3033]

Far as I can tell sometimes the escorts are blind and deaf. Over 3 day period in Jan '43, I attacked 2 convoys south of Ireland, both escorted by 5 or 6 destroyers.

I approached 1st convoy at periscope depth and the lead escort thought he found something, launched 3 patterns about 300m from me. Then he gave up and I was able to penetrate to the middle of the convoy, got a T3 and a C3. Made a clean escape, as far as I could tell NONE of the escorts even looked for me! Never heard a single DC warning...

I penetrated the 2nd convoy without alerting ANYBODY, escorts never changed their usual patrol pattern. Got 2 T3's and another clean escape. Far as I could tell the escorts never even knew anything happened.

Just to make sure they weren't dead, I reloaded a save and made a surface attack at flank speed, got spotted and had the cr*p beat out of me. Don't know why they couldn't find me before, or at least react to what I'd done. Running stock 1.4, no rub.

[_alphaBeta_]

@ DirtyHarry3033

Perhaps the lead escort happened to be facing the other direction both times. They wouldn't be able to hear you, and you'd be outside the ASDIC cone.

If I'm getting detected in 1940, then there's something going on here. I've attacked a couple of convoys since this post came out. Keeping your distance certainly does the trick as long as you don't make much noise.

[Charlie901]

You all definatley need to DL this Mod which is included in RUB by default.

http://www.subsim.com/phpBB/viewtopic.php?t=40222

I's called the: SonarDC_20

Mod by Jungman

Very interesting post and improves the A.I. ships using Sonar 110%

Actually makes it more realistic and tones down the original game settings.

to quote:


The Minimum distance to detect is better now at 150 meters instead 200 meters.
Game default is zero range!

[_alphaBeta_]

I have the mod, and it is excellent. I also recommend it.

[AlanSmithee]

I second both Charlie and alphaBeta. I can't envision how late war would be survivable without the sonar mod - assuming that late war is survivable in any case!

As a bit of a postscript, since my earlier problems I've encountered two more large convoys. In both cases I was able to sneak by the lead escort through careful manuvering and exploiting holes in the escort screen. Lots of fun after that, including sinking my first troop ship. What I found interesting after that was how easy it was to get away. As long as I went deep and moved in the exact opposite direction of the convoy, the escorts never even came near me. Look what a little bit of knowledge can do! :up: :know:

[Mowgli]

Well I have just had a nightmare experience.
Mid atlantic in my VIIC late 1942. Large convoy only two escorts heading east. In I go. Four fish at 3 C2 and 1 C3. Two hits, full astern hard to port. Stern tube fire. Two sinkings and only two measly escorts to worry about. Then what happens a larger convoy heading west with numerous escorts who all decided to have a pop at me.

Ping decoy bang. Ping decoy bang. Eventually crept away to the south leaving two disabled C2s sitting there. Returned when quiet to try and finish the C2s. Who was keeping them company but three escorts. The stricken vessels appeared to carry out repairs and steamed of at 7knts with escorts trailing.
Never seen that before. No wish to meet two convoys passing again either.

Going to carry onto my patrol area off Halifax and listen to some relaxing music.

[tycho102]

I've such a difficult time keeping up with all the mods! :rotfl:

MaD Pr0ps out to AlanSmithee, and Mr. Ron C, for answering an old question of mine. I would certainly guess the escorts stopped pinging when they turned back to "listen" at the convoy.

I've always wondered if convoys tried to tip-toe through the Atlantic, and now I see they did not. Interesting that the bridge team was dialed into the feedback, such that they themselves became sonar operators. :ping:

Boy, those days are gone. Nowadays, it's an art.

[_alphaBeta_]

As long as I went deep and moved in the exact opposite direction of the convoy, the escorts never even came near me.
That's usually what I do as well. Just be careful of the trailing escort that it sometimes there. You'll walk right into that trap if you're not ready. If there is a trailing escort (which for me is almost always the case) I'll go out one of the sides while moving with the convoy. The escorts will have difficulty finding you in the convoy and will concentrate their search where the convoy has been. This leaves you a clean exit right out the side.