Tips on Evading Detection Before Attack?

[Raskol]

I've got TMO 2.0 installed with the easier AI optional mod, playing RSRDC.

It's Jan 1942, my second patrol, I'm ranging around in the makassar strait in a Sargo class, no damage. Clear skies, a light breeze, calm seas. I pick up a big convoy with over a dozen smoke trails on the horizon, and maneuver to a spot about 5nm in front of them, directly in their path, go under. From the sonar station I can hear about 4 destroyer escorts in front of the convoy, so I turn my nose directly into them and head down to 450 feet at 1 knot on silent running---the idea being, I guess, to keep moving into the middle of the convoy, wait until the forward escorts have passed, then pop up in there and pop off some shots at point blank range. I know I'll be detected once I get shallow, but I don't care by that point---I'm shooting then going back under. Evading after the fact isn't the problem, I just want to get in there.

The problem is, it seems that no matter what I do, the escorts detect me as soon as they're close. The thermal layer is at 150 feet. I'm sitting at 450 feet, giving them the slimmest possible profile, but I'm still getting pinged as soon as they pass over me. Then it's alarm sirens and the whole convoy is zig zagging before I even start my ascent.

So is this sort of approach doomed to fail? Or just how deep would I have to go in order to avoid getting pinged?

Also, I've been operating under the assumption that the active sonar cone is directional--iow, if I start going up to periscope depth once I'm in the rear hemisphere of the escorts, I won't be pinged. Is that correct, or does it extend all the way around, so that the only real blind spot is underneath the escort?

[SgtPotato]

Did you use the silent running?

[Raskol]

Yeah, I start running silent at about 5 nm out and stay that way, and get down to 450 feet before they're within 9000 yards, and at that point there's never any course change or other sign I've been detected.

It's right as they're passing over me (well, some time between 2000 yards in front and 2000 yards behind me) that I get pinged and alarms go off.

[JoeCorrado]

I usually make my approach from one side of (perpendicular to) the convoy. Coming in from the side, I can present as small a profile as possible to the escorts. Coming straight in (0* relative) through the destroyer screen you will ALWAYS present your full profile to their sonar at some point, and usually to multiple escorts at "can't miss range" to boot.

If you are able to get around the convoy and set it up, try coming in from one side or the other. You should be able to close to within about 2500 yards (1000 yards distant from the escorts who may be 1500 yards from the nearest column = 2500 yards) without being detected. If you can dictate the timing of the attack, it is always better at night. Less chance of your torpedoes, or your scope being seen.

Taking your best shots at the most inviting, and still unwary targets from a range of 2500 yards, at a decent angle, is better than trying to get closer, only to be detected and try hip shots while in the middle of a bunch of stampeding merchantmen. Balance optimum range against against risk detection. Remember, if you are detected before your trap is sprung- all will be wasted and you will be lucky to nab any of the best targets and still get away to talk about it.

Number and placement of the escorts will dictate how close you can get, but you should be able to close the range without being detected to the point that you have a fair chance at inflicting serious damage and also escape without too much undue risk to your own boat.

Of course you "could" try the O'kane method and risk a surfaced torpedo attack. Running TMO though- I wouldn't advise it.

Crippling a ship will likely turn into a kill if you are able remain undetected after the fact... eventually the escorts will lose interest in you and abandon their search; and the wounded ships in order to rejoin their panicked flock... leaving the stragglers to your tender mercies.

[Raskol]

Yeah, that's how I usually do it; I should probably stick to that. I wanted to try this way, though (well, partly I *had to* because I hadn't been able to get a good handle on the convoy's speed to plot an intercept course at any other angle), even with all the disadvantages you rightly pointed out.

It's not so much that I'm attached to approaching this way as a bit confused at the detection capabilities of the escorts. I mean, you would think it would be enough for them to detect me on the ascent, but I'm keeping down to ranges I wasn't even sure the sub could take and still getting caught by active sonar!

I ran the approach again a few times, and even running down to 500+ feet I'm still getting pinged and then they're sending depth charges close enough to rock the boat. And this is in January of 42.

Is that something that's intended in TMO? It makes it incredibly difficult--maybe even unrealistically so IMO. I remember reading that until later in the war the Japanese didn't even know subs could go below 150, and didn't ever set depth charges to go off below there---but I'm getting pinged at 500 feet and deeper, and then bombed accurately enough that it feels like they can see me.

So anyway, just how deep does their active sonar go, assuming best conditions (worst for the sub, that is)? Is it even possible to go deep enough to go "under" it if you don't have rough weather?

[magic452]

Some have had some success going to 600 ' but don't think a Sargo will take that. Didn't think it would take 500'.


I only come in from the side and usually at PD At 1/2 knot and shoot a vector analysis or O'Kane from 2800 or more yards at an approach angle of about 70°. Helps keep you clear of the flanking DD.
Pick the one or two biggest targets you can get at and fire and than get the heck out of Dodge. But this is not with 2.0 as I want to finish my current career first. Maybe very soon though as I just got a photo recon of Singapore. August 44. Playing dead is dead. If I die 2.0 goes in.

What you have is with the easy AI, just think what the hard AI is like.
Ducimus is just evil.

Magic