GWX's "uber" AI demystified

[Tobus]

The AI's ability to hear you depends on a few things:

A.) The state of the sea.
If the sea is calm, sonar conditions are greatly improved. If the sea is rough, sonar conditions are craptastic to say the least, and for you, this is good news.

b.) Engine RPMS.
It's not your speed per say that the AI qeues in on. Its your engines RPMs. When setting your speed, use the interior free cam and take a close look at your engines RPMS. 100 RPMs is usually the maximum i would go in a silent running scenario.

c.) Your position in relation to the escort. Looking back up at the picture of the aspect, you'll see a big semicircle around the destroyer. The area behind it, is its deafspot, or its baffeles. Its also deaf to anything DIRECTLY under it, at or around a radius of 10 meters. Depth charge attacks DO NOT mask your noise. Only when an escort is directly above you, or if you are directly behind an escort are you completely safe to use as many RPM's in your motors as your heart desires.

I was reading a book, "" U-boat killer" by retired destroyer captain Donald Macintyre (http://www.uboat.net/books/reviews.html/title/260), in which he clearly states that hydrophones were not used anymore on British subhunters since the 1e world war. ASDIC was the only means of hunting down u-boots. So what's this with "hearing" subs due to their enginenoise and other noises like pumps, reloading and repairwork? It seems to me everything of sound IS modelled in SH3/GWX.

Can you clarify?

[joea]

Ahh tobus, they used both, or to use the modern terms "passive" and "active" sonar. ASDIC just provided a more accurate way of pinpointing the sub's location and depth. Hydrophones were ONLY passive, if you look at the same site, http://www.uboat.net/allies/technical/asdic.htm it says:

ASDIC in a passive role

The device could also be used to listen as well as pinging. The propeller noises of the U-boat would sometimes be heard as well as its operation of various machinery and its use of compressed air in the ballast tanks to change depths. This was not very usual as one of the standard German tactics, when located, was to dive deep, rig for silent running and hide beneath a thermal layer at speeds slow enough to eliminate any cavitation from the propellers.

Problem of course is many SH3 skippers are not as careful as their real-life counterparts in keeping quiet.

[Tobus]

Thanks Joea, that clears that up! Do you know anything about my remark about DC's messing up ASDIC'ing for 10 minutes?

[joea]

Originally Posted by Tobus

Thanks Joea, that clears that up! Do you know anything about my remark about DC's messing up ASDIC'ing for 10 minutes?

I read they have, but not in SH3 apparently. I think GWX did something to simulate DCs messing up the ASDIC but not sure.

[Tobus]

Originally Posted by joea

I read they have, but not in SH3 apparently. I think GWX did something to simulate DCs messing up the ASDIC but not sure.

Don't think so. I got plastered bigtime last night by no less than 4 escorts. I lived to tell the tale, but at times it almost sounded like an MP-40 with DC's going of. Still, one of the buggers was happily pinging away at me.

[Tijn]

Great post, it was a really nice read. One question though, when talking about early war sonar en later war sonar. When was the change? somewhere late 42?

[raymond6751]

My Dad was in destroyers in the war. The best tactic used when multiple escorts were available was to have one stop and listen while the others pinged or circled. The circling ones were at a distance and the sub could hear those.

The listener would tell the others when the sub was heard.

Not all escorts, especially early war, had sonar. Hydrophones were the most widely used device until about 1941 mainly due to the need to pull a ship off duty to install, test, and train. They just didn't have enough escorts to release many to port.

Very early Canadian convoys often had only one or two ships with DC on board too. The others were dummy escorts, without even guns. They would harass the subs to keep them down while the convoy got away.

The movies don't show the reality of the situation faced by the Allies early in the war.

[Penelope_Grey]

One tip I have to offer on this when a destroyer is coming at you, because it is risky, and though it seems to work in early war.

when the destroyer is coming at you from whichever direction, crash dive and head down to 80m incase of Depth Charge drops. turn the U-Boat to face towards the oncoming destroyer, which will be going at ahead flank. As the Destroyer gets nearer, go silent and use silent speed (2kts). What I found is, the destroyer will pass over you heading to the location where he saw you on the surface BEFORE he goes active. Which gives you precious moments to get away from the spot where he seen you, and you can most of the time slip past them, they won't expect you to come towards them. If however they do go active, your acoustic profile will be at its most minimal so you may just get away with it. If not, deeper.

[Jimbuna]

Originally Posted by joea

I read they have, but not in SH3 apparently. I think GWX did something to simulate DCs messing up the ASDIC but not sure.

It is in GWX ...but only for a few minutes

[Hitman]

One thing I don't see modelled in Ducimus 1st post is the lack of shallow depth coverage for sonars:hmm: A U-Boat at periscope depth can be heard by hydrophones, but can't be pinged by ASDIC. Why is the asdic cone then fully convering all area till the surface? I believe I saw a "MinDepth" para meter in SH3 Mini Tweaker (Set to zero in both stock SH3 and GWX), while it should have been deeper. Anyone can confirm the effect of that parameter and if reads the depth of sonar cone at the maximum horizontal range?

[P_Funk]

Any advice about the actual pinging and how to know when they've locked onto you or if they are just pinging randomly?

I'm curious becuase sometimes when I'm being pinged its like they're right on top of me and the frequency of the pings increases til I get the classic "depth charges in the water sir". However sometimes its like they're pinging and they pass nearby and don't pick me up.

[Ducimus]

Originally Posted by Hitman

One thing I don't see modelled in Ducimus 1st post is the lack of shallow depth coverage for sonars:hmm: A U-Boat at periscope depth can be heard by hydrophones, but can't be pinged by ASDIC.

In GW11A that was true, but not in GWX. Theres a Min and Max elevation of trhe beam. A minElevation of 0 means the beam is horizontal to the surface with no blind area. In GW11a there was a min elevation of like 9 or 15 or some such number, which angled the upper part of the beam downward, creating a blind spot. This is why people could stay at periscope depth and not get pinged. I always thought this was really cheesy and am glad it was removed in GWX.

Originally Posted by P_Funk

Any advice about the actual pinging and how to know when they've locked onto you or if they are just pinging randomly?

Nope. They generally don't ping without reason, but just because their pinging doesnt neccessarily mean they have a strong signal on your position.

[KeptinCranky]

I really really wish I had read this entire thread in the quiet moments at work before doing this:




Maybe the brave crew of U-36 might have returned home to collect their medals and appreciation from the Frauleins

The 5 tribal DDs escorting this here HMS Hood really didn't appreciate me doing this

My first patrol in GWX, what an introduction

[sth128]

Originally Posted by KeptinCranky

I really really wish I had read this entire thread in the quiet moments at work before doing this:

Maybe the brave crew of U-36 might have returned home to collect their medals and appreciation from the Frauleins

The 5 tribal DDs escorting this here HMS Hood really didn't appreciate me doing this

My first patrol in GWX, what an introduction

My first patrol after GWX, I got pwnd by a cargo ship with one deck gun (yes, I used to play stock SH3 with my deck gun blazing, using torpedo only as back up... I was a good shot, usually taking out their deck gun within seconds!)

[Kaleu. Jochen Mohr]

Originally Posted by sth128

My first patrol after GWX, I got pwnd by a cargo ship with one deck gun (yes, I used to play stock SH3 with my deck gun blazing, using torpedo only as back up... I was a good shot, usually taking out their deck gun within seconds!)

same problem here but with torpedo's.
i used to destroy most ships with 1 torpedo. but now i have to use 3 or more