Details on escort evasion

[Barkerov]

Last night I delivered some hand written messages to a large Jap freighter which was on its way down the slot toward Guadalcanal. The messages were carefully transcribed onto two steel tubes a little over 16 feet in length and 21 inches in diameter. Great care was taken to deliver them safely to their intended destination. The trouble is my Japanese is not all that good and I think I have offended them because 4 destroyers are now pinging/depth charging me for my efforts.

I went as deep as I could (200ft in my little S-Class) pointed in another direction and I am crawling along at 2.5 knots on silent running (75 RPM). I am wondering if there is anything I can do to improve my chances of getting away.

Can I go deeper and if so how much?
Should I up the RPM to 100 or back it off to 50 or less?
Should I throw in a few turns? If so how much rudder deflection do I put in?
35 degrees seems to slow me down to a stop just about.

Surface conditions an hour ago were clear with a 6 m/s wind. Any advice you can offer would be appreciated.

[TorpX]

Can I go deeper and if so how much?
Should I up the RPM to 100 or back it off to 50 or less?
Should I throw in a few turns? If so how much rudder deflection do I put in?
35 degrees seems to slow me down to a stop just about.



I'm going to assume you are playing stock (it makes a difference).

I will sometimes go a little deeper than 200 ft., but not much. No more than 220 or 230 ft. Mods can change crush depth.

If you are trying to be silent, keep to about 50 rpm's if possible. However, understand evasion takes priority over stealth. If an enemy can is making a run, and about to depth charge you, he already knows you're there, so you need to move - PRONTO!

The best way to evade a run is to first start acceleration before he drops. With experience, you should be able to judge he is starting a run before you hear the splashes. Start speeding up (use full, or even flank speed), a minute or so before he is over you. If you wait until you hear the ashcans splash, it is too late. After you have a little speed and know what direction he is coming from, start turning. For example, if he is bearing 190°, and starting his run, the bearing moving toward 195°, turn to starboard. If his bearing was moving toward 185°, you would turn to port. The idea is to turn out of his path, before he gets there.

I will usually put the rudder hard over, but as you found out subs don't turn well under water (especially the S-class). I use ISP which helps the turning issue a great deal (stock ship physics is really terrible), but if you play stock, you might have to make less abrupt turns. I wouldn't try to evade, or make turns at 2 knots; it's pointless.

After you have dodged his run, coast to a low, sustainable speed like 2 kn. or so, and hope he loses you. Another thing, don't use up your battery frivolously, you may need it later.

[Barkerov]

I meant to say I am using RFB so until I hear otherwise I will keep her at 200ft.

Thanks for your advice :salute: the take home message seems to be hit the gas and turn when they are about to start a run on you. When the booms start lower the throttle back to 50rpm and head in the same direction.
I had been trying to turn at 15 degrees rudder after I moved out of the circle of death but perhaps they reaquired me because I was too noisy at 75rpm.

I did not cop any damage but I did manage to get a speed boost from one charge. Does that mean it was very close?

[cloadmcally]

Well as far as I know that little stupid depth charge was about to take out a tooth of your chief petty officer :har:

[Armistead]

I'm not sure of the depths of RFB. Keep in mind many factors before you attack that will help you make decisions or evade later. I will try to ID the escorts so I know what I'm dealing with. Some types are more deadly, carrying multiple Y guns and double roll offs. I'ts basically coded what comes hunts you, but more often if you attack from a flank, those on that flank come.

Assuming you know all the common stuff, silent running, getting below the thermal, keep in mind these two.

Weather, the higher the wind/waves the less they can hear you, at high winds they're basically deaf and it also greatly effects active sonar, but not to the same degree.

Your angle, keep yourself as narrow as possible to escorts. If you give your broadside to an escort, much more likely he will ping you.

When under attack, most do as Torpx explained, harder to do in a S boat, because the deeper you go, the more time you have to outrun charges. They basically dump on top of you, so when you hear them crank up to make a run, you hit flank and try to outrun them before they reach you. Much easier in a Gato at 500 ft. Personally I don't do a hard flank turn, but a small S turn, hard over a few sec, hard back over, then s8. Often if they have Y guns a hard over turn takes you way out where they are coming down.

Also, depending on your mods, some vet escorts are mean. I have many in mine set to elite and they are rather deadly hunters, often making runs together and they come at you from many angles and will dump further ahead of you. Always big fun when you have 6 deadly Type AB's dumping 100's of charges on you.

Be smart, plan your attack with you can get factors stacked in your favor. Your goal should be to get off your attack and get out of the zone where you shot the torps from before escorts get there, as they generally hunt where the torps spawned from unless they get a fix on you.

Here are a few elite escorts working me over, coming from different angles, almost running each other over to dump on me.

http://i651.photobucket.com/albums/uu235/Armistead1424/SH4Img2011-04-01_205842_418.jpg
http://i651.photobucket.com/albums/uu235/Armistead1424/SH4Img2011-04-01_210927_380.jpg
http://i651.photobucket.com/albums/uu235/Armistead1424/SH4Img2011-04-01_211053_396.jpg
http://i651.photobucket.com/albums/uu235/Armistead1424/SH4Img2011-04-01_211428_790.jpg
http://i651.photobucket.com/albums/uu235/Armistead1424/SH4Img2011-04-01_212030_794.jpg
http://i651.photobucket.com/albums/uu235/Armistead1424/SH4Img2011-04-01_205517_572.jpg

[Barkerov]

When under attack, most do as Torpx explained, harder to do in a S boat, because the deeper you go, the more time you have to outrun charges. They basically dump on top of you, so when you hear them crank up to make a run, you hit flank and try to outrun them before they reach you. Much easier in a Gato at 500 ft. Personally I don't do a hard flank turn, but a small S turn, hard over a few sec, hard back over, then s8. Often if they have Y guns a hard over turn takes you way out where they are coming down.


Thanks for your input, I have the general idea down by it is the little things like this that give you an edge. I will keep the S turn in mind but I had always felt that if they knew where you were they also knew where you were headed, hence my reasoning for wanting to change the direction of my escape. The other thing I was thinking is that if you turn back to complete the S turn, do you still gain enough lateral separation from the first half of the turn?

At any rate I figure if I can do all this in an S-class boat I will be able to do it better in a fleet boat.

[TorpX]

Armistead has some good advice.

Like he said, if there are several escorts hunting you, you're in for a rough time. On thing about the game is that they can only ping to their front; meaning after one passes above you, you are in his blind spot, and have a short grace period when you can safely maneuver. This doesn't apply if there is more than one, though. Also, he is certainly right about not all escorts being created equal.

Even when the escorts locate you, they cannot easily tell where, or how fast you are going, but one guiding escort can direct an attacking escort, and improve their aim. As they get very close, they will lose contact (you will no longer be in the sonar 'cone'). The problem is that if they have depth charge throwers, they don't have to be exact, to catch you somewhere in the pattern.

The other thing I was thinking is that if you turn back to complete the S turn, do you still gain enough lateral separation from the first half of the turn?


Imo, it is better to avoid more complicated turns like a 'S' turn. It will probably be difficult to complete a simple 90° turn, much less anything more, in the time available. You should time your boat and check how long it takes to make a 90° from a low speed start, so you have an idea how long it takes. You really just want to get as far away as possible from the pattern. You can always make another turn after you dodged the attack.

[Rockin Robbins]

SH3 & SH4 "Uber" AI Explained (http://www.ducimus.net/sh415/ai.htm)
This is a detailed explanation of how escort sonar works and how to handle your submarine to give you maximum advantage. It also explains how the enemy AI works so your strategy can actually work FOR you instead of being counterproductive. This work is of vital importance to any player of SH3 or SH4 especially if running GWX in 3 or TMO in 4.

This is probably the best description of escort evasion ever written.

[aanker]

Excellent advice in the above posts regarding evasion. Not much if anything to add...

I am a 'Sugar Boat' fan too. S-39 (SS-144) was my 'first PTC command' and has been 'my boat' since 2001 or so. : ) early in the War.

I try to plan my attacks for evening into night whenever possible, especially in a S class.

The S class does have a little speed advantage while submerged, and I try to use it to move away from my firing position fast - while trying to keep a low profile. That is my shallow water Yellow Sea technique.

Typically the Escorts will begin their search heading to your firing location, so try to put as much distance from there as you can, fast. You may be able to avoid submerged DD evasion altogether.

If you can sneak away beyond their visual range, surface, and clear the area. At night this can be as little as 1,800 yards under the right conditions.

Good luck, and Happy Hunting!

[Barkerov]

SH3 & SH4 "Uber" AI Explained (http://www.ducimus.net/sh415/ai.htm)
This is a detailed explanation of how escort sonar works and how to handle your submarine to give you maximum advantage. It also explains how the enemy AI works so your strategy can actually work FOR you instead of being counterproductive. This work is of vital importance to any player of SH3 or SH4 especially if running GWX in 3 or TMO in 4.

This is probably the best description of escort evasion ever written.


I actually read this a couple of times before I posted. I found it very helpful but it was the little details I was after. Some were not included in that explanation.

[scubamatt]

If you are in close to a point of land or a harbor, sometimes you can get the attacking tin can to run aground or break off its attack, but that is very dependent on the situation.

I just try to clear datum as soon as my fish are on the way (max speed, and/or deep dive), and I usually determine the thermal layer before I attack, so I know the 'ceiling' I need to get under asap. After that its try to keep my profile 'end on' towards approaching escorts, low rpm unless they are making a run (then I sprint and do a turn, coast afterwards).

Don't forget that being rigged for silent running means your DC team won't effect repairs...