Pinging from destroyers?

[Washington]

Hey guys,

When a destroyer starts to ping the water....what is his range and what is the pinging data telling him? Does he ping only when he knows you are out there? Doesnt the ping just tell him your bearing and range, but not your depth? How do you lose the destroyer? There are so many questions and no info in the manual!!

[gimpy117]

he pings when he knows you might be out there... the destroyer is attempting to get a range and bearing on you. They only do this when A. They are reasonably sure there's a boat around or B. Know your there and want a better fix on your position it can also tell depth

The best way to avoid it is dive
I hit crash dive and get down as quick as possible then "Rig for silent running"
this lowers the sound of your props making it harder to detect by passive sonar (hydrophones) and a little harder for active. So far in 1942 200 feet and the first thermal layer seems to throw them off when your at silent speed...

hope that helps happy hunting.

[Jaeger]

hi,

the asdic has a range of 1000 - 2500 meters, depending on time in war. in sh3 there is a bug in the AI; they start pinging when you are in active range, independent of your noise level. (silent running or full stop doesnt help to avoid the destroyer to start pinging.) they also start pinging when they havent any information about a subs existence in this area. the only way to avoid a DC attack is to stay out of his active range. when in range, go as deep as possible and try to slip away after an attack run. in the passive range, try to get your noise level as low as possible. stay on periscope depth to take short looks at his actions and try to max out the distance. when detected, go deep and man your hydrophones personally. when you can hear an acceleration of his engines, he will start an DC run, then its time to increase speed to flank an change the area. after his attack run, when he slows down, go back to silent running.


edit: the pinging data gives him your position (including depth). for smallest chance to get pinged, show him your smallest silhoutte (try to hold him on 180 degrees on hydrophone)

edit2: lol, i am in the sh4 forum. sorry, i dont know, if the AI bug is also in sh4...


Jaeger

[-Pv-]

Once under pining attack the game gets a lot harder. Best not to let that happen. Experience will go a long way (just as it did in real life) toward learning how to out-smart the AI and not get into the ping evasion cycle. Once you getting pinged, the enemy is most blind while directly over-head. Use sprint and turn tactics to get into an unexpected position where it takes the DD a while to aim the sonar in your direction going quiet between sprint-turns. This is an art and not easily learned. Takes practice. In modern subs it's called the "dance of death."
-Pv-

[Nisgeis]

I read in one review of SH4 that the reviewer heard the escorts switch from low frequency to high frequency pinging. Was he imagining it? I've never had that happen to me.

I also get a bit hazy on the whole pinging thing. As far as I know active pinging is from supersonic projectors, but is it actually audible in the submarine, or can only the sonar operator manning the supersonic receiver hear it? It's so common in films for the whole crew to be able to hear it, but you never know if that just for dramatic effect (or perhaps played through the sonar set speaker).

[-Pv-]

It's the ping rate and volume I hear change when they've got you bracketed with the pings getting closer together and louder as they get closer in the game. I believe WWII active sonar was clearly audible. It takes a LOT of energy (lower frequencies) to travel distances and return with enough energy to get clear detection. Especially back then. We can hear wales and dolphins when they echo range and the environmentalists sure are concerned our pings are killing wales. It's doesn't take frequencies we can't hear to be "supersonic" in water since transmission is faster than in air.
-Pv-

[Sailor Steve]

It is audible, but probably not in the way the movies show it. I don't remember which one, but one German captain said it sounded like pebbles being thrown against the hull.

[-Pv-]

I believe the early "ASDIC" type sonars were wide band and consisted of the "ping" we are familiar with. Later sonars used "chirps" pulses of several frequencies closer to the clicks we hear from dolphins which might sound more like the "pebble" effect. As the war progressed, different types of sonars were produced.
-Pv-

[fireship4]

Any way to make destroyers and the like constantly ping? From what I've heard thats what they did in the IJN. Then you could pick up a task force from their pings before you see them and before you can pick them up on sonar.

Is there volume variation in the game when the pinging ship is further away?

Lastly does anyone know if there were slow and fast ping rates in use by the IJN?

[DavyJonesFootlocker]

As a rule I go as far as 300 ft depending on ocean depth. Turn off all torpedo loading and any repairing. Get below a thermal layer. I had 8 Subchasers and 2 DDs after me and about 3 hrs managed to elude them.

[MarkShot]

A pinging platform pings at a faster rate the closer it gets. Why? It takes less time for the sound to travel back to the sender. So, the sender does not need to worry about overlapping sendings and receiving.

So, in games like DW/SC besides the volume of the ping, the frequency of the ping also indicates how close the sender is. The pace of pinging by a homing torp gets quicker and quicker until you are dead.

In these games, I have noticed variation in ping volume, but I think there is different sound played when they have you located.

In AOD/SHCE, pinging volume was modeled with distance. When they had you, you could clearly hear a different sound. With SHCE, you could hear a shift in the ping as crossed a thermal layer.

[The Thorn]

What about the decoys? Does anybody use them to escape from enemy ships? I read that they are for distraction for sonar but I have not much succes with using them. Does anybody know how to use them in a good and effective way?

[-Pv-]

I haven't used them but the typical technique is to use them to make a lof of noise while you change depth and direction at minimum noise so when the enemy figures they are following a false lead, you are in an unexpected location frustrating their search.
-Pv-

[fireship4]

BUMP

Would still like to know if its possible to get destroyers to ping all the time as I heard that they used to.

Also is it possible to make the sonar sounds more realistic by changing them depending on the movements of the ship? for example higher freq if the ship is approaching visa versa if it is moving away.

[Hylander_1314]

If the enemy starts to ping and has a good idea where you are, go as deep as your boat will go, rig for silent running, and manually set your speed for 1/2 knot. Your exec wil sound out set speed to "0", but if you look at your boat from out side, your props are still turning about 50 rpms. They make very little noise, and you can better judge when they start the D.C. run, deploy a decoy, and then go to flank speed and turn hard to port, or starboard, and try doubling back 180 degrees from your previous heading.

Once you've turned 180 degrees from your last heading, drop another decoy, and creap away at 1/2 knot, using flank speed bursts when they drop more ash cans on your decoys.

Once you've put some distance between yourself and the DD's, stay at that 1/2 knot speed and soon they will give up the chase. If you have a convoy around, they will try to detect you in closer to the convoy, when you are actually leaving the engagement zone.

[Pikes]

I was trying to evade in shallow water and my experience was this in SH4: The destroyer just did circles, i couldnt work out why, no attack run. I would sit on the bottom and watch him whilst silent.

Any idea what the game is doing here, is he still searching? Does sitting on the bottom get modelled with the smaller return? Does shallow water have any game effect we've noticed?

[Buffalo9]

Active and passive are two different animals.

If the enemy is actively pinging there are a few reasons why, 1) they know your're there or near, 2) they are trying to keep subs on the defensive. If your trying to evade then your immediate threat to them is diminished.
The change is ping interval(rate) is a good indicator that they see something and are trying to update the contact info quicker for an attack run.
In shallow water active sonar is not as effective, but this also depends on the bottom conditions, ie: boulders, clay, etc. If you are amongst objects that cause a sonar return they may have difficulty in deciphering the returns. Going silent or bottoming out is not always the best solution, when getting pinged silent running does nothing for you but slow you down, get away first then go silent.
When active sonar is used passive sonar's effectivness is diminished proportional to the rate of active pinging.
And yes, keeping the smallest aspect ratio is always a good idea.

[fireship4]

I may have been misunderstood.

I heard previously that japanese patrols used to actively ping ALL the time and were often discovered this way (it is easier to detect a pinging ship than for it to resolve your sub it seems).

I was asking if this can be introduced.

PS does anyone actually know if they used different ping rates at that time and on those sonar sets?