so i'm sitting at 20m in the middle of a convoy...

[capt_frank]

dead still rigged for silent. i had already made my torp run and was waiting for everything to settle down so i could use my stern tube against a stragler.

i got pinged, no problem i thought, i'm at dead calm, no one is making any noise.

along comes a destroyer and dc's me...now i'm slightly damaged only to the extent of the conning tower.

still no movement from me...

along comes the second destroyer and dc's me rite on the money...

and that's all she rote, i'm dead.

question: how could they find me at dead still rigged silent??!!

oh, it was july 1940...viiC

[Dowly]

I`m not too familiar with hydrophones and stuff, so this isnt 100% correct what I`m about to say.

Destroyer with that ping-thing (cant remeber name of it) is like a bat, and you are prey. The destroyer sends a sound going thru the water and when it hits you, the sound is mirrored back to the destroyer. So that`s how he know where you are..... i think!

[Gizzmoe]

As you said, they pinged you, with active sonar. The sonar ping/wave bounced of the submarine and travelled back to the destroyers hydrophone. With passive sonar you only listen to underwater sounds, so when you are silent they can´t hear you.

[Dowly]

Originally Posted by Gizzmoe

As you said, they pinged you, with active sonar. The sonar ping/wave bounced of the submarine and travelled back to the destroyers hydrophone. With passive sonar you only listen to underwater sounds, so when you are silent they can´t hear you.

That`s what I meant, I`m just not too good at explaining things!

[capt_frank]

so does that mean when i'm pinged, i'm "ponged"?

would a lower depth help? i was at 20m... :hmm:

[seafarer]

Active sonar is high frequency, pulsed sound (ie. a "ping"), sent out by the shio searching for you (as opposed to hydrophones, which just passively listen for your sound). If it hits you and the ship sending it gets the return, you are locked.

If pinged, you need to MOVE, change depth, change heading, use decoys (if you have them). Sitting silent and still is a death call if actively pinged - they now know where you are and will hammer you.

MOVE.

[cunnutazzo]

also, it's important to show the minimum Uboot surface to the enemy sonar.

[Sawdust]

Originally Posted by capt_frank

would a lower depth help? i was at 20m... :hmm:

I used to "hide" at periscope depth, but I've had much better luck by hiding at greater depths, say 50-100m. (Just be sure to know how deep the water is!)

[gdogghenrikson]

I usally hide at 25 meters

[capt_frank]

thank for the info guys!

frank

[Gairith]

I run to 50m and drink a cup of coffee. If pinged I go to 75 or 80m and refill my cup I just spilled.

[Mike 'Red Ocktober' Hense]

yup... someone said it best up there... when you're pinged, your pretty much ponged...

20 meters is just about 60something feet or so... ya gotta get deeper than that if possible... and ya gotta be able to manuever, once those depth charges are in the water...

... and if the Kriegmarine sub store has any of that Alberecht (?) anti asdic stuff... get some, and coat your sub with it before going out on patrol...

coat your crew with some of it too if they aren't acting right

--Mike

[djv]

Well, if you are ponged, deeper is better, I think. It was in SH1 and SH2 and in RL.

SH1 had tempreature inversions too, that helped.... Would that be moddable? Lemme search.

edit Searched: not an issue it appears.

[Mowgli]

I am sure someone more knowledgable than myself could explain better but here is my take.

In the early "The Happy Days" you could lurk at periscope depth and wait into one of the convoy columns. The DDs equipment in those days was not so hot at shallow depths.

Later in the war, with their newer improved equipment they started to kick a*** big time and the happy days were over.

I am in early 42 and never, never lurk at periscope depth in the path of a convoy now. Well off to one side at about 50 metres I surface and fire at around 2000 metres. Then I am down deep and scuttle away like the big girls blouse I am. My men love me

[TreverSlyFox]

An Active sonar "Ping" tells the enemy "Where" you are, it doesn't tell them how "Deep" you are, that is purely a guess on their part.

When you get pinged, listened to the return and how "fast" it is, in other words how quick the return "ping" echo is. Ping.......................Ping they'er a ways off. Ping...Ping they'er right on top of you.

If your hearing that Ping...Ping GET MOVING and CHANGE DEPTH AND HEADING!! He's on top of you and is making his run on you, Depth Charges to follow real quickly. He doesn't really know how deep you are but most likely he's going to set his depth charges for varying depths to "Bracket" you. First two charges at 30 m then two for 50 m and maybe two for 70 m or some combination like that.

If your sitting still your dead meat!! If you listen closely as he starts his run on you you'll hear him accelerate (screws pick up speed), Hit Flank Speed, Change Depth and Hard Over Pt or Stb.
As he passes over you, your in his baffles and he can't hear you at all, plus the noise from the depth charges going off. After the last depth charge goes off, CUT your speed to 3kts Silent running again.

Just remember, if your ass end is pointed at him, he's in YOUR baffles and you can't hear him. Never sit still if you being actively pinged from close range, change heading and depth all the time.