GWX Team - convoy screen thoughts

[MarkShot]

The pop-up attack is definitely doable. You got about 15 minutes diving and about 15 minutes ascending. For a big convoy, you have adequate time get pass the forward screen and ascend into the middle of it while watching for collisions with the observation scope.

[Jimbuna]

Originally Posted by MarkShot

I am going to start working on something new today.

Instead of trying to slip in the front door at 25M at 1kts, I am going to try to come in at about 220M at 1kts. I think this will reduce the chance of ASDIC if I fail to nail the gap in the screen. Also, if they do detect me, it will be good to be deep. If I nail the gap, then I will blow ballast and pop up. Silent, of course.

How do you blow ballast silently (presuming of course your into a certain element of realism play

[MarkShot]

Actually, in timing it, I don't think there is much difference between hydro planes and blowing balasts while keeping shaft RPM at 100.

So, realism aside, it's about 15 minutes to come up and shoot.

I know that I will never meet the high standards of the GRP (GWX Realism Police). Not even if I get a waterproof laptop and play in the shower with subwoofers shaking the bathroom!

* Above said in the spirit of jest ... no real insults implied or intended.

[Jimbuna]

Originally Posted by MarkShot

Actually, in timing it, I don't think there is much difference between hydro planes and blowing balasts while keeping shaft RPM at 100.

So, realism aside, it's about 15 minutes to come up and shoot.

I know that I will never meet the high standards of the GRP (GWX Realism Police). Not even if I get a waterproof laptop and play in the shower with subwoofers shaking the bathroom!

* Above said in the spirit of jest ... no real insults implied or intended.

Likewise Kaleun

[Pablo]

Originally Posted by MarkShot

The pop-up attack is definitely doable. You got about 15 minutes diving and about 15 minutes ascending. For a big convoy, you have adequate time get pass the forward screen and ascend into the middle of it while watching for collisions with the observation scope.

Hi!

As discussed in the GWX Manual, early war sonar has a shallow downwards-looking angle: a deep approach works well because you are below the sonar detection cone by the time you are in detection range. Late war sonar can look down at very steep angles, and so the escorts are more likely to detect you at closer ranges when equipped with these types of systems.

@Markshot: These sonars start becoming more prevalent in mid-1943, which is why everyone keeps telling you to try convoy attacks in mid-1943 or later. They aren't always there, but you will know when they are.

Pablo

[MarkShot]

Can you really have fun just pouncing on lone merchants?

For me, what I love about all these games is the stalking, the attack, and the escape. I realize that war isn't supposed to be "sporting", but for me I play this as a game. So, passing up the convoys just takes all the fun out of it for me.

[Pablo]

Originally Posted by MarkShot

Dear GWX Team,

As always, thanks for your wonderful mod.

I don't know how much control modders have over the convoy screen formation and the screen's behavior.

Hi!

We have no control over the escort formations except in scripted single- and multi-player missions. We have been able to get the escorts to vary their paths and perform an active search every once in a while.

An now my feedback ...

It is my impression that the convoy defense is too heavily weighted to the flanks and rear.

I can consistently slip by the screen at 25M when that screen contains 6-9 escorts. Typically, there will be two escorts positioned forward. However, one of two will be considerably more forward than the other.

The AI puts the escorted ships into a box formation, and spreads the escorts around the convoy in a circular formation, with escorts equidistant along the perimeter of the circle. This is why there are generally only one or two escorts in the front of a convoy, but we are unable to change it since the formation-creation logic is hard-coded.

Generally, screens are not that hard to penetrated if you have an accurate course for the convoy and then can key in on the single most forward escort. You side step that escort with three key techniques:

(1) Silent running at 1-2kts.

(2) Time (you arrive way in advance ... thus, despite your low speed) the long lead distance gives you time to position.

(3) Depth. At 25M you have enough slack to drift upwards while making 1kts.

Once you clear that single escort, the convoy is open to you.

Okay, how could this approach be made harder:

(1) More escorts leading.

(2) More forward area in front of the covered by escort motion.

(3) Randomness in escort searching as opposed to predictable swings back and forth.

Now, I am not sure that anything can be tweaked, but for #1. However, I would think #1 might be promising. I would assume that the convoy's greatest vulnerability submerged is from the front. Your sub is constrained on close approach to only 1-2kts. There is limited opportunity to thrust in from the flanks; and none from the rear. Even if a flank attack is feasible, it requires much more skill than a forward attack. Why? The forward attack is highly passive based on letting the convoy come to you. The flank attack requires substantial repositioning of your U-boat both in a relative and absolute sense.

So, I would tend to think that the convoy would put up a strongest defense if 50% of the escorts were allocated to sweep ahead of the convoy. Of course, this configuration might not be historic, but I think it would increase the challenge of attacking GWX convoys.

The vulnerability I see to such approach is the pop-up attack. I have heard that despite moving very slowly and deep that the u-boat can blow ballast and rise rapidly to attack without alerting the escorts. I personally have not used this technique. A less uniform screen might make this style of attack easier.

Comments?

Convoy formations changed over the course of the war; eventually, you would find one or two flank escorts per side and a rear guard, with the rest of the escort in front of the convoy. Some of these remained in formation; others prowled about in front of the convoy and could be ordered to track down any U-boat detected by HFDF-capable ships in the convoy.

We have tried to use historical formations in the historically-based single- and multi-player missions, but the escort AI is not as smart as the humans which it attempts to emulate, so even historical formations are not as effective as they were in real life: escorts rarely "prowl" anywhere, and generally stay in formation. They will not execute a "Raspberry," "Half-Raspberry," or any other historical escort response to a U-boat attack other than to congregate in the U-boat's general area and search for it; however, they will use one escort to track you while the others maneuver to attack based on the reports of the escort that is tracking you.

The Silent Hunter III convoy setup and operations AI limits our ability to put historical operational approaches into practice. We could double or treble the number of convoy escorts, but Allied technical advances can make that a very tough proposition after about mid-1943, when the Allies start getting more advanced sonar.

Pablo

One other point.
It is, after all, a simulation.
No one can give each ship in game that one special thing.
The Human element.
An scort can only work with the AI the Game has.
It does not have a "Gut" feeling.
It has limited experence as the game defines it.
Those are very different from real life.
You find the holes in the game.
Nothing special there.
I defeat games all the time by finding the flaws.
You want a "smarter" AI.
I doubt you get one without going too far the other way.

[MarkShot]

Thanks for the explanation of how the AI works.

I have seen some of this myself, since when practicing in some of my saved checkpoints, I watch the AI on the surface after I am sure that I have given them the slip.

From what I have seen, there are usually only one or two active searchers. I use the word active here not in a sonar sense, but in the sense of driving the situation. The active searchers appear to continuously circle to see if they can pick you up as they make their circular run. If they don't trip over you, then they double back on the spot where they had you and drop another pattern. The other escorts sit more or less still at further distances, I guess either waiting for a report of your updated location or that you might foolishly pass directly underneath them.

I will agree that the AI is a bit weak. In a strategic sense, the addition of escorts doesn't seem to vastly complicate the sub's task of escaping. Having played AOD, going from 4-7 escorts can often be the kiss of death, because they form an impenetrable circle which you will never break out of. Also, they attack much more aggressively and force a great deal more movement to avoid destruction. Thus, you get maybe 10 good runs, before your battery has nothing left. I find that in this game, I can milk a battery for evasion for a very long, long time. Someone had once offered an analysis of I think SH1 and escort behavior showing how each escort contributes to tightening the window of escape such that by the time the 8th escort appears, the window is only about 10% of the circumfrence wide such that it is almost impossible to nail it and escape.

Thanks again. I'll continue to explore the game.

By the way, does SH4 play pretty much the same? I have it and mods installed, but haven't really been playing yet?

[MarkShot]

Bump - see screenshot. Added a place to download the redline mod for those who have been asking. Credit to Rubini as I adapted his work for my own personal needs.

Rubini, if sharing this is not cool, then let me know and I will take it down and stop responding to requests for it.

Thanks.

[Pablo]

Originally Posted by MarkShot

Thus, you get maybe 10 good runs, before your battery has nothing left. I find that in this game, I can milk a battery for evasion for a very long, long time.

Long battery life is in line with historical capabilities. A Type VIIC U-boat could go about 80 miles at 4 knots, and the Type IX about 65 miles at 4 knots while submerged on a battery charge, so having a flat battery after evading only 10 depth charge patterns seems a bit on the low side to me. Historically, the hunter-killer groups just camped overhead until psychological factors or battle damage forced the boat to the surface or killed it.

By the way, does SH4 play pretty much the same? I have it and mods installed, but haven't really been playing yet?

Hmm... your best bet is probably to check the SH IV fora. IIRC the stock escort behavior isn't very effective, but modders have been tweaking things to make them more effective.

Pablo

[MarkShot]

The point I failed to make is that game play wise (I know nothing of realism), resource management; battery and compressed air have a much greater role in AOD than SH3. I've never really felt up against a wall in SH3 when it comes to battery charge or compressed air. For game play, it makes things more interesting and challenging when trying to decide what to do when time and patience are not the only factors.

[MarkShot]

I should explain. The 10 runs I mention in AOD isn't really for escaping patterns. That's 10 runs assuming that they have your position fixed. Once they have you fixed, running does no good. Your best chance to survive the pattern and break contact happens at the moment of the attack. So, during the attack you run to avoid the pattern, but you also do your most extreme and radical maneuvering, since you have a short window to break contact. You can avoid the pattern using a lot less battery, but for sure after 5-15 minutes they will detect you again. So, you use your battery in an extreme fashion to try to displace during the attack from your known position such that they fail to reacquire you. That's where most of your battery investment goes.

The best policy of course is never to be detected. Shoot and scoot. This is possible in AOD and SH1, since the passive sonar is not nearly the equal of SH3/GWX. So, when you have some distance, you can move at a good clip.

Once detected, the best policy is break contact as quickly as possible. The more escorts that form up in the hunt for you, the more rapidly your chances of survival falls. So, break contact when only the initial elements have you. Unlike SH3/GWX, they will all participate in hunting you down if given time. Also, escorts can easily invest 1-2 hours before sprinting back to the convoy.

Once the hunt for you is in full swing and they have contact, then you crawl along and try a slow feint in a false direction. Your ultimate goal is to try create a situation where multiple escorts immediately following the attack will tend to be grouped in the same quadrant. You will attempt to exploit this by using the temporary gap this leaves with them all clustered in one area. You must get enough distance from where they will resume looking for you before they rebuild the circle. You have to use the cover of the attack and good noise management to get this distance. If you do it right, they will fail to immediatly reacquire and they will fail reacquire when they widen the search after 15-30 minutes.

Both SH1 and AOD have good escort hunting coordination, but AOD is by far the best I have seen. AOD also makes screen penetration quite hard too. Not so much due to the passive sonar sensitivity of SH3/GWX, but their searching behavior which provides much better coverage and randomness. They always have their active sonar on, but unlike SH3 ... there is not a one sensor enabled limit. Visual, passive, and active can all be engaged at once.

Also, both SH1 and AOD truly prevent any accurate measurement of escort distance from your sub. All you have are some volume and pitch factors, screw sounds through the hull, and bearing rate of the contact arc. More deductions are required to play the game of cat and mouse.

Each game has differences in game play and AI strength. Thus, I play all. Beside graphics and sound SH3/GWX does offer game play challenges too. This is why I was eager to get to 1943. I wanted to stop simply counting tonnage and once again feel that my very life might be in jeopardy. For the moment, it seems to be.

[Pablo]

Originally Posted by MarkShot

I should explain. The 10 runs I mention in AOD isn't really for escaping patterns. That's 10 runs assuming that they have your position fixed. Once they have you fixed, running does no good. Your best chance to survive the pattern and break contact happens at the moment of the attack. So, during the attack you run to avoid the pattern, but you also do your most extreme and radical maneuvering, since you have a short window to break contact. You can avoid the pattern using a lot less battery, but for sure after 5-15 minutes they will detect you again. So, you use your battery in an extreme fashion to try to displace during the attack from your known position such that they fail to reacquire you. That's where most of your battery investment goes.

That was my assumption. Real U-boats could dodge under water for about a day or so before being forced to surface, barring damage or other factors that could force the U-boat to surface sooner. The convoy escorts were supposed to stay up with the convoy, and so would generally stick around just long enough to ensure the U-boat could no longer threaten the convoy; the hunter-killer teams did not have this constraint, and would latch on to a U-boat until the U-boat sank or surrendered.

This is why I was eager to get to 1943. I wanted to stop simply counting tonnage and once again feel that my very life might be in jeopardy. For the moment, it seems to be.

OK, good. Say, if you're still looking for a challenge in 1944, and keeping to history isn't an issue, then I suppose we could always re-enable the "laser-guided depth charge" capability from stock Silent Hunter III, where the ASW ships always set their depth charges to explode very close to your actual depth....

Pablo

[MarkShot]

I have been doing more testing.

The deep approach followed by a pop-up attack on the outside of the convoy seems very effective. It allowed to use TC substantially without immediately being found. I got my shot taken and was able to get away without being localized. Finally, I was able to go deep and evade while maintaining 3kts.

Shallow approachs when combined with TC invariably met with being localized and pinging. As soon as I upped the TC, the escorts would accelerate towards me. Yuck - but I don't have four hours to approach in 1:1. However, the pop-up looks good.