Diving deep to avoid DDs
 

spring of '42, Tambor class thermal at 190ft. (TMOwtw, no other mods)

I was trying to escape from a couple of very aggressive DDs. I had tried various methods of sneaking away, to no avail.
They'd find me, start pinging and run directly over me and drop charges. This went on a long time, I tried diving deeper.. made it down to 535ft ok, but they still found me ?????
I did notice the background noise in the boat (good job guys) but it seemed to be loud and staying on. And the DD's also stayed after me at 535 ft.

When diving deep do the surface ships hear the creaking? That would take trying to escape deep out of the mix. I came back up to about 350 and crept SLOWLY away .

Any thoughts here?

I'll let you know. I'm about to attack a large convoy (I think I'm about 4,000 yds out) and there's lots of escorts. Did I say I'm new at this and this is my 2nd mission with SH4?

If needed, and I don't get rammed, I'm planning to go deep, rig for silent running, make turns for 1 knot, and show as little profile as possible.

Hope somebody can give you a better answer.

TMOwTw, if I'm not mistaken, put the thermal layer back to almost stock (aanker??), so it should help. If it's found at 190, you would go to about 235 then, to have the whole boat below it. Put the throttle telemetry on 1 knot, or use the rpm gauge somewhere below 90, if it's functional in TMOwTw (50-90rpm), and "Silent Running". Already have an "escape" route picked out, and go that way, stay that way, slight turns every once in a while. Warning though: if it's daylight, and a calm sea, you'll need an additional step: Bend over and kiss the moon goodbye... :salute:

Generated noise is linked to one thing and one thing only: shaft rpm. Like it was mentioned set your speed manually and creep away slowly at 1-2kts.

I had done exactly what everyone suggested. And I usually try to sneak off at 1 knot. What surprised me was that they kept pinging, seemingly accurately.

By the way.. where is that RPM gauge? I've spent much time scanning all around the interior. Obviously I found the deepest depth gauge.

Stock and some mods don't have them easily available, if at all. In TMO-based mods, if you're in a fleet boat and in the Control Room, they are on the un-occupied stand to the Chief's right. In the Conn, they are to the Helmsman's right on his station. In both cases, it's a grouping of 4 small gauges, 2x2, maybe just above waist height... Some mods, you can click on them and set the rpm. Others, they're window dressing, and you'll have to fiddle with the knot gauge to get the rpm down...

It is difficult to not panic or worry when you hear continuous pinging, but patience is key, as is realizing you will take damage. The main ingredient is proper attacking, which is just biding your time, and attack where / when appropriate - if possible...

https://www.youtube.com/watch?v=MMGHMSM2Tk8

:salute:

That "Knot Dial" is the second half of the Telegraph Dial, along the bottom right of your task bar. You can set specific slower speeds then what the Telegraph will give you there. By clicking just below each Dial, you'll get a different set of Dials/Gauges. The Compass will produce a Rudder Gauge to individually set the rudder to a certain degree of angle. The Shallow Depth Gauge turns into a Deep Depth gauge.

========

As far as the interior ambient sounds of the sub goes, there is no capability of lowering the volume when you would like it to....like when silent running. Just a part of the game the developers didn't quite get right, and there's nothing we can do about it. This background noise DOES NOT effect the enemy detection though....it has no effect. It's the subs RPM that triggers a sound detection, plus the capability of the enemy to find the sub with "active" sonar (that's the pinging you're hearing), no matter how little of noise you may be producing.

As it turned out, I used too many torpedoes to do it, but did manage to sink two freighters. It was sort of dark, I got spotted, and a few cannon shots came in my direction. So I guess the four escorts had a good idea where I was. At that point I did all the normal escape things: turned away from the convoy, dove deep (320 ft), rigged for silent running, set speed to AA 1/3 and set one knot on the speed log dial.

I did hear one depth charge go off early on, but it wasn't close. I just remained silent and deep and eventually the escorts returned to the convoy.

But... There was no active pinging involved as was your case. Had there been, I would have made sure to show as small a profile as possible, preferably a stern view, which I didn't see mentioned above. I think it's a big factor when active sonar is after you.

Ahhh... but the game doesn't do "profile" the way you would think... there have been conflicting reports from the field - and it may not matter - or, (horrors :o ) it might be "reversed". Further CapnScurvy luh-bore-uh-tory testing is needed (ya can't get that "CSL Approved" sticker without it!)... :salute:

Dunno if this will help, and am unsure how you currently set up your attacks, but in the stock game, I have had success setting up at 1000-1500 yards 90 deg from the main target bearing line at depth, working to minimize exposure at the depths where they can hear me. (duh :doh:)

• starting out below the thermocline (usually 200-250 ft), I configure the torpedo settings and confirm silent running.
• Beginning the ascent puts the crew on battle stations.
• Pause at 150-160 feet (below most DD hearing) and survey the situation on the plotting board.
  • Assuming no nearby "sidekick" DDs, when the lead DD passes past my 11-12:00, I start to ascend, watching the tracks of the targets, trying to get the main target ship at 40ish degrees ascending through 100 ft or so,
  • the attack periscope is raised and set at the approximate target bearing.
• Once at periscope depth, I acquire the target(s), track and fire. (If using the O'Kane method, that will be 10-12 degrees before the boat's 12:00)
• As soon as the torpedoes are launched (as a rule, 3 for large ships, 2 for medium, one for small), I silently submerge toward 250 ft while moving ahead at 1 kt, determine which DD is likely to be a problem, and formulate a plan to avoid him.
• As soon as I am safely below the thermocline, the speed can increase to 5 kt and zig zag evasive maneuvering begun to have the stern pointed to the nearest DD much of the time, using the zig zags to check progress.

Since this is in the stock game, YMMV with TMO.

Good hunting!! :Kaleun_Salute:

Propbeanie: in your reply, you added a video, I looked to see what it was going to show.. but It's Credence Clearwater Revival..

Is that what you meant to send?

Thanks all,
I found the RPM Gauges, and got the info that game AI doesn't 'detect' the background noise, just the ship's RPM noise.
And, thanks to all the strategy clues, I have been doing most of them anyway, but it's always good to get reinforcement of what I'm doing.

An overall understanding of detection is...…..there's MANY ways a sub will be detected!


1. Visual: Within the parameters of the game (modded or not), the sub can be detected by visual means within specific distances; specific time periods the sub is exposed; specific amounts of sub "size" actually exposed to the visual sensor. This can come from ANY enemy source......Plane; SanPan fishing boats; Land installations; etc.

2. Sonar: The same as Visual, but in different area of detection...….one is above the waterline; the other below the waterline.

3. Hydrophone: The subs noise level from its engine RPM value. Enabling Silent Running simply works as a "modifier" to a calculation of RPM, Distance, Depth, of the sub.

4. Messaging: You send a message/report to base...….detection occurs if an enemy is within a certain specified distance.

5. Firing a torpedo or deck gun shell.....no better way of telling the enemy where you are is by firing on him.


AND, with any of these initial processes, there are additional "modifiers" that come into play that can either "enhance" the detection capabilities, or "detract" from the calculation. Such as, how long the detection time period will be "active" before the enemy will go back to its non combative state; Or, how the environmental conditions play an effect on detection.

Lot's of ways to be detected!

:O: I'm just referring to when the best time to attack is, which is "The Night Time, Is The Right Time". CCR just happens to be my favorite band from when I was a kid... :yeah: - barring a night attack, some "chop" to the waves, or maybe some light rain. When it is perfectly clear, high noon, glassy sea, that's when they'll see your boat from 12,500 and put an 8" shell through your conn, or if they don't see you then, they'll "hear" you under the water, and find you with some boom-boom cans... :salute:

One thing no one mentioned is the DD crew AI. There are different settings on the skill level. Stock uses random levels. TMO has all the levels set to the highest. RSRDC sets them consistent with the period of the war, with some random differences. If you encounter a crew that is set to the highest level, then any historical accuracy doesn't count. That crew will be able to find you at night, while you are silent running below the thermal layer. Also, they will not let up until you are destroyed, they are out of cans, or have gotten too far from the convoy.
:Kaleun_Salute:
If you get a lowest level crew, then they could miss you during a clear day, while surfaced, and firing on them.
:Kaleun_Wink: