Periscope detections are hosed

[neilbyrne]

I'm really getting disgusted with having brief exposures of my periscope detected immediately and at very high rates of probability by merchant ships, day or night. Had one detect me last night at 4000 yards in heavy seas. This has been happening for about a week. They get to 4,000 yds and start to zigzag for no apparent reason.
I served on active duty in the USN for 31 years mostly in frigates and destroyers. I had command of a frigate, BRONSTEIN, and a destroyer, BRISCOE. Persicope detections are very hard and you get lots of false contacts. For most of my time as a junior officer, seniors kept telling me that periscope detections by lookouts were a training problem. Then I got a look at about 30 years of SHAREM ASW exercise results and the opportunities vs. detection numbers were just dismal. Obviously, I can’t put classified numbers out here, but suffice it to say that the US Navy has ultimately decided that this is a job for a machine.
A warship has about seven folks looking out full and part time. Three are full time lookouts, port, stbd and aft. Then you have the OOD and JOOD who look out when they can. Last you have the two signalmen who are supposed to be looking out when not signaling; although, in fact, they hardly do. The lookouts have 120 degree sectors that do not overlap. The officers, when they are looking, normally search the forward 180 degrees. The aft lookout has no one else looking where he searches and his primary responsibility is to be the last line of defense for a man who falls overboard, so often he is searching in the near field which the others are not.
In eighteen years of sea duty, I saw less than half a dozen unalerted visual periscope detections that actually turned out to be submarines. Now admittedly, we weren’t worried about being torpedoed, and so our attention was less focused than that of our WWII brethren, but still, not great. This is not to say that I only saw three or so periscopes in 18 years of sea duty. I saw a lot more than that, but they weren’t initial detections. When sonar gets a contact, they call the bridge and CIC requesting a bearing clear or foul report to determine if what they've got is a surface ship or not. The bridge watch standers then look down the bearing sonar gave. Sometimes there’s a periscope there, but these are cued not unalerted detections. If I had to attach an unclassified number to uncued detections, I’d say a warship had no better than a 10% chance, perhaps less, of detecting a periscope that wasn’t way high out of the water and then only in daylight within 4000 yds and merchant ships would certainly do no better. At night, or in low visibility, or heavy seas, forget it; zero percent. The issues at night and in low viz are obvious. In heavy seas the lookout has two problems. First, the eye is most often drawn to the periscope feather, its wake. In heavy seas, foam presides and feathers are insignificant. Second, you can't search with binoculars because you can't steady the field of view. IJN warships had wonderful optical equipment and most destroyers had two sets of big eye mounted binoculars in the pilot house. USN big eyes run to 20X power and are useful for ship recognition, but relatively not for periscope detections because of their narrow field of view.
Surface search radar, until the relatively recent advent of one and two second scan rates in systems like SPQ-9, was only a little better than visual. This was mostly because with six to ten second scan rates, everything as small as a periscope looks to the operator like sea clutter. And we didn’t get good at sea clutter rejection features until after the war. Plus radar sea return clutter is worst right where you’re wanting to look, within 6kyds of own ship.
I wrote two longer posts about ASW for Ducimus about five years ago that contained some of this. In any case, does anyone know where the periscope detection numbers reside so I can examine those and see if what I perceive is happening is in fact the case?

[Sniper297]

That I couldn't tell you, but since I've been fooling with the SH4 mission editor I found that by default every new ship I place is classed as "Veteran", with the choices being Elite, Veteran, Competent, Novice, and Poor. "Veteran" apparently means psychic, making a beeline for you from far beyond any reasonable detection range. In other words the AI cheats so I'd hate to see an Elite crew.


I too was in ASW, an AX in a heavy helicopter antisubmarine squadron, so I totally agree with your gripe here.

[TorpX]

neilbyrne, I certainly agree with your reasoning. Whenever someone posts about their scope being spotted at > 1,000 yd, I have to scratch my head. I feel the same way about the way enemy ships are able to spot torpedo tracks. It seems to defy logic.

Someone posted about the same problem a few months ago. They said the instant he put up his scope, the target started to evade. Later, he said he changed up his mod order, and the problem went away. What mods are you using?

[Armistead]

I used the keys to control the scope so I can move it as I please, this way I can leave it under the water line and just barely move it up to break water enough to see. Beats all the up and down all the way during an attack.You really need to just break the waterline with you scope in calm waters, can get by more in rougher waters, fog and night of course.

I haven't messes with files in a long time, seems there is some sim files that deal with the scope, also possible different min/max heights that may could be adjusted and I believe there's a value regarding speed, the wake your scope leaves, so be careful about speed when scoping.

Obvious, use the attack scope during the day..

Scury would probably be the one to ask about this.

[Sniper297]

I'm still working on Manilla Raid and Resupply, so I've been observing the behavior of one Fubuki over and over. The group is one Hiryu, two cruisers, and I eliminated all but one escort. Manila Bay is shallow, the spot I attack from is 120 feet deep, so there's no going deep to evade. Got three wrecks screaming the breakup sounds of tortured metal all around, but I put the scope down and switch to external view to watch - I go north, south, west, or settle on the bottom, kick out decoys, nothing changes. He makes a beeline for me every time. I changed his path to put him 4000 yards away from the group, he still knows exactly where I am and where I'm going. Changed him from Veteran to Competent, there's STILL no evading him.



I know a lot of tricks to fool ASW operators, but I have to change him to Novice and place him way outside sonar detection range when I start the attack to get an even chance of actually evading this poltergeist. Periscope exposure and noise are irrelevant, the AI cheats.

[Armistead]

Haha, the AI doesn't cheat, it just follows the values set for it. It takes time to understand those values and how to deal with them, but the AI, even difficult settings like TMO or worse can be defeated..

[neilbyrne]

I've been having the same problems detailed above with escorts zooming in from all quarters for no apparent reason. Two nights ago I encountered a very large convoy (6 columns of 5) east of Formosa. I made three attacks on these guys all using the same tactics just to make sure I wasn't being paranoid about uber capable escorts. In each case I would run around them on the surface. Get twelve or so miles ahead, go to radar depth and track them in until the closest escort was 8nm distant then go to PD and silent running. Oh yeah, this was all at night. The only strong escort was an OTORI, the rest were corvettes and trawlers. The OTORI was on the convoy's stbd wing so I stayed to their port. I had their speed from radar and I'd lay out a speed vs. bearing track on the main body so I would pick up any major course change and keep periscope obs. to a min. Layer depth was 230ft. None of these tactics, nor keeping the lead escort pointed made any difference. At about 4kyds fm the nearest escort, the closest three escorts would turn right at me. Happened every time. This is OCT '44.
So sonar detections are as hosed as periscopes. Here I’d like to go into sub detection by escorts with sonar. I have a lot of experience with this, and it is very difficult. It's why between us and the Brits, we built 1600+ destroyers/escort vessels in WWII. There is strength in numbers, because the individual capability just sucks. In 1970 ASW School, we were taught the capabilities of all the sonars then in the US surface fleet. There were still some WWII ships active, mostly old FLETCHERs and SUMNERs that hadn’t been through the FRAM (Fleet Rehabilitation and Modernization) refit that installed newer systems. As I recall, these old girls had the SQS-46V sonar. We did a day or two in the attack trainer using this system. In absolutely beautiful water, isothermal (no layer) to 400ft, it had a reliable detection range of 2000-2500yds. Now remember this was the best sonar we had toward the end of WWII. In worse water, it was less. And a good rule of thumb about subs below the layer is that range across the layer is no better than 33-25% of range above the layer so that an above layer range of 2kyds yields a below layer range of 650-500yds. The IJN had nothing better than this, and in my research in Morison’s 15 volumes History of USN Ops in WWII and Roscoe’s histories of US Sub & DD ops, I never found a sub detection at greater than 2,500 yds on active sonar. Most IJN detections were at 2,000 or less. On passive sonar, those sonars could detect thermal (steam/oxygen) powered torpedoes pretty well but close in to own ship; electrics not at all. The only condition when a sub on her battery would be at all vulnerable to passive detection was if she were cavitating her screws, normally at 7kts or more and only above 150ft depth, or at 15kts or more below 150 but above 300ft. Deeper than 300ft, water pressure keeps the cavitation bubbles from forming. And even those detections were a long way from a sure thing.
Max sonar speed for WWII escort ships was 10-12 knots and it was not graceful degradation above that. From 10-12, count on losing half your range, go faster and you were deaf as a post in both active and passive.
The idea that the IJN could passively detect a non-cavitating sub on her battery is fantasy. The USN did not field a surface sonar with a really decent passive capablilty until the SQQ-23 (PAIR) IN 1969. PAIR had two completely rubber sonar domes, much more acoustically transparent than the conventional steel and enormously improved signal processing and displays. The PAIR test ship was USS BROWNSON (DD-868) in which I was CIC and then ASW officer. We took PAIR thru OPEVAL, the tests required to determine acceptance for service use. The sub we tested against was USS JALLAO (SS-368) a BALAO GUPPY. We did months of test runs together. JALLAO would open range on us with all her top hamper, periscopes, radar, comm antennae way out of the water so we could track her out to ~30kyds on radar. Sonar was kept in the dark as to her position. Then she would turn toward us and energize an acoustic augmenter to sound like a Soviet nuke boat. CIC would pass word to sonar the run had commenced and they'd try to detect. PAIR passed OPEVAL based on the results, but the reason I went into all this detail is that on the conclusion of the run, JALLAO would secure the augmenter and she'd be GONE off our sonar displays. I mean we wouldn't even have to wait for her to tell us she'd secured; we knew immediately.
So there we were in 1970 with a state of the art sonar, rubber domes, cabinets full of jacked up signal processors, JALLAO shuts down the augmenter and we can't detect her just on her battery. Plus detecting her on battery wasn't even part of the PAIR spec because everybody knew it couldn't be done. Even today, conventional subs on battery are the hardest passive ASW target there is. The idea the IJN could passively detect twenty-five years earlier is fanciful.
So where are these 4kyd detections coming from? In reality they can't be active or passive sonar or periscope detections at night; so what are they?

My mods:
Generic Mod Enabler - v2.6.0.157
1_TriggerMaru_Overhaul_2-5
1_TMO_25_small_patch
RSRDC_TMO_V502
RSRDC_V5xx_Patch1
Convoy Routes TMO+RSRD
1.5_Optical Targeting Correction 031312 for RSRDCv502
1.5_OTC for 16 to 9 Aspect Ratio RSRDCv502
Improved Stock Environment_v3_TMO&RFB
#2 ISE Realistic Colors
Easier AI for TMO 2.5 by Orpheus
EZ Plot V1.0

[Sniper297]

The AI cheats, there's no other way.



AQS-13/A from a Sikorsky SH-3D antisubmarine helicopter, 1978. Max range 20,000 yards, but only under ideal conditions, and in passive mode you MIGHT hear a noisy surface ship at 10k yards. They would have loved that in WWII, but regardless of how good any sonar is - you can't hear what's not making noise. Soviet nukes back in the 70s had some pretty noisy reactor pumps, that's why they went back to diesel electric with the KILO class. Our subs were really quiet unless they were running fast and shallow, I know exactly what you mean about the augmenter.

WWII the technology just wasn't there, the way the hunter-killer groups in the Atlantic found Das Boot was by flying radar equipped Avengers off of jeep carriers - at night. On the surface. After that stick a pin in a chart and draw a 100 mile radius circle, patrol that circle - he has to come up somewhere in that circle within 48 hours. Every time he pops up to recharge batteries the TBMs get him on radar, attack again to force him under, repeat until power is gone and he can't stay submerged.

In SH4:



With wussie mode on you click on a tin can, and get the circles. Outer is visual detection (in good weather), 5500 yards. Inner is passive sonar, 3800 yards (really optimistic for WWII), the wedge cut out of the back is the dead zone (from screws and machinery noise, good place for a sub to sprint). The half circle in front is active sonar, 550 yards (again in ideal conditions, sub shallow and at a 90 degree angle).

Again, I've done some testing on this, if a destroyer is 10,000 yards away when you torpedo a nearby ship, no matter which direction you go, how fast or slow, how many decoys you kick out or how deep you go, the clairvoyant AI will make a beeline straight for you every time unless the crew is set for novice or poor.

The problem may be programming limitations, but every aspect of the AI is oversimplified. Worst example is your own crew's limited intelligence;

"SHIP SIGHTED! BEARING 065! LONG RANGE!"
Yeah, that's the 83rd time you reported the same ship, we're in the middle of an end-around, if you lose sight of him for a few minutes you don't need to report him as a new contact every time you reacquire him.

BAM!!! "WE'RE UNDER ATTACK SIR! WE'RE TAKING DAMAGE SIR!"
Cripes, where did that evil destroyer come from?
"I REPORTED HIM 15 MINUTES AGO, SIR! FIVE MINUTES AGO HE TURNED TOWARD US AND WENT TO FULL SPEED, BUT I DIDN'T THINK IT WAS IMPORTANT TO MENTION THAT SINCE HE WASN'T A NEW CONTACT!"
Scurvy dog, go walk the plank.

Originally Posted by Sniper297

The AI cheats, there's no other way.

yes the AI cheats, there is no denying it.

its designed like that to make the game challenging to players. the trick is to learn how the game cheats and the ways you can fool or get around its attempts to cheat. you can even use its cheating against it to cause it to chase ghosts.

its a skill set to learn and it takes time but once you get used to it you learn how to limit the things you do in the game so it isn't able to be as successful at cheating you.

bottom line is, it is a learning curve you must master to be able to balance the games cheating with things you can do to limit how the game can cheat.

think of night as a clear bright day because they can always spot you at night just as if it was a clear bright day.

even when there is no way for the enemy to know your position and you are making no noise with the scope down and all engines at full stop and are completely silent, a DD will still be able to zoom in from 6000m away and park exactly on top of you and drop charges when it isn't possible to ever detect you to that level of accuracy. the enemy ships deck guns can hit a nail on the head from 10,000m away 3 out of 5 shots so your periscope or conning tower are both spotted and hit by shells beyond any realistic human degree of detection. these gunners that are more accurate from a moving deck platform have to be the best snipers in the world to make such blatently unrealistic shots.

the only thing that can help you beat the games AI in most cases is the thermal layer and to a lesser extent the weather like storms and fog because it misdirects the enemy sensors enough so you can escape detection.

the game does many unrealistic things to try and keep you challenged and into the game and give you a realistic "feeling" of impending doom even though the way things function and happen in the game is very often far from being realistic about the things subs did in real life.

you cant do night attacks under cover of darkness because the games AI doesn't detect you any less at night then during daylight. you try a surface night attack, even in bad weather, and your dead.

there is a long long list of things wrong with the AI in the game that isn't realistic but its not as much about the settings and how they work as it is about the overall feel you get when playing. they are trying to give you the "feeling" that you are really there facing things real captains did.

another thing I hate about the game is when you are inside a convoy or task force, how every ship in the game always knows exactly where you are at periscope depth, even without ever putting your scope up, and manages to be able to drive right on top of you and ram your tower every time. battleships, cruisers, carriers, and freighters all will play pinball with your tower.

sometimes when a ship is near you, the AI tells it to stop and mirror your movements to stay "too close" for your torps to arm so you stop they stop you turn they turn and it is not possible for then to have that close a fix on you speed, position, and range or be able to create a Mexican stand off like that. its simple to break free by suddenly hitting full reverse and break free to avoid it but the realism killer for a battleship to stop dead in the water just so you cant get enough space for your torps to arm is beyond a realism killer for me.

the truth is, if the game didn't cheat it would quickly become boring and no challenge to play it.

the first thing I suggest is do a mod soup cleanup then try again and see if things are better, the game will always cheat "some" so don't expect it to stop all the unreasonable detections. also as torpx mentioned there is a mod conflict issue that if you combine certain mods it can cause you to be constantly detected all of the time even when you shouldn't be so list your mods and the install order lets see if anything is wrong with it.

[neilbyrne]

Mods listed in order shown above.

Sniper, where is it that I can set escort performance values? Can you get to something that borders reality? I don't find giving the AI freebee detections at 6kyds to be fun.

[Armistead]

Originally Posted by neilbyrne

Mods listed in order shown above.

Sniper, where is it that I can set escort performance values? Can you get to something that borders reality? I don't find giving the AI freebee detections at 6kyds to be fun.

This explains enemy values and how to change them. However, I wouldn't do much, the fact is the AI basically makes up for other flaws of the game. Most long time players can use the hardest mods and still rack up unrealistic tonnage per patrol.

http://www.subsim.com/radioroom/show...=111395&page=2

[neilbyrne]

Armistead, thanks for the lead.

I don't care about tonnage or that folks learn to work around these fantasies. What I'm trying to get to is something that's more real. I sometimes play this with my best friend who is a retired USN CDR; one of us on the keyboard and the other running manuevering board solutions on escorts & targets. It's fun but we're growing very weary of having something crazy happen where we look at each other and say, "Now that's bull****; I mean not a chance that happens."

But from what I can read so far, the AI is based on concrete that was poured on oozing ground. It won't go active unless it detects passively for some period which was impossible at the time. So if I turn off passive sonar, the escorts will go blind in both eyes.

I'm going to have to play with this some I guess.

I played thru the war three times on TMO 1.5/RSRDC several years ago and don't remember it being this bad for realism. Occasionally something goofy would happen, but nothing like this.

[Sniper297]

Don't get me started, the whole thing is goofy. When I examine files I find many many that are not used at all in the game - they're leftovers from Silent Hunter III. Another example of oversimplified programming is layers - as former subhunters, you and I understand the nature of thermal layers and all the reflection/refraction/reverberation stuff. In game the thermal layer works like another surface layer, line of "sight" from sonar. If you're on or above the surface or any part of the sub or periscope sticks up, the enemy can see you. If you're completely under the surface you're "invisible".

Layers work the same way, the bathythermograph sensor is on the keel, so when the stage whisper comes "PASSING THERMAL LAYER!", only the KEEL has passed the thermal layer, so if you stop there sonar can still "see" you. Note the depth when the whisper comes, go down 60 feet deeper than that, now the whole sub is "submerged" under the layer and can't be detected at all. Come up 20 feet so the periscope shears are above the layer, and you will always be detected at the same range that you would be visually if the shears were sticking above the actual surface.

In other words the thermal layer in the game is a kind of "virtual surface" for sound, simply a flat plane you're either above or hidden below. I know real layers are nothing like that unless there's a seriously sharp difference in temp and/or salinity, but I take advantage of them anyway - the enemy cheats so why shouldn't I?
In fact when there's time I make a deep submergence before the target arrives so I can note the depth if there's a thermal layer, add 60 feet and make a mental note of where I'll go after the attack - usually I avoid being depth charged at all that way. Fire all tubes, observe hits if there's time, then kick out a decoy, go to flank speed, head for 60 feet below the layer, then slow down to avoid wasting battery juice. I don't even order silent running, let the crew clang and bang while reloading tubes, if I'm under the layer they won't hear it.

[Armistead]

Originally Posted by neilbyrne

Armistead, thanks for the lead.

I don't care about tonnage or that folks learn to work around these fantasies. What I'm trying to get to is something that's more real. I sometimes play this with my best friend who is a retired USN CDR; one of us on the keyboard and the other running manuevering board solutions on escorts & targets. It's fun but we're growing very weary of having something crazy happen where we look at each other and say, "Now that's bull****; I mean not a chance that happens."

But from what I can read so far, the AI is based on concrete that was poured on oozing ground. It won't go active unless it detects passively for some period which was impossible at the time. So if I turn off passive sonar, the escorts will go blind in both eyes.

I'm going to have to play with this some I guess.

I played thru the war three times on TMO 1.5/RSRDC several years ago and don't remember it being this bad for realism. Occasionally something goofy would happen, but nothing like this.

It's a balance of numerous values, I seldom had a problem getting found out with TMO until I got my attack off and could always evade unless I did something stupid. I did fine tune all my values, some harder, some easier, but I don't recall having a problem with the scope being seen unless I leave it up too long or going to fast. However, I do just raise it above the waterline. I haven't played in a long time, but maybe the visual sensor in the sim file has a min/max height value that could be adjusted, I just don't remember.

The AI sonar will only come on if you fall within its sonar cone, give it the right angle and depth. As long as I stay narrow to an escort, I seldom get pinged unless I get within 1000 yards. Someone did make a exe file mod/cheat of sort that you have to run after you start the game that turns active sonar off until you're found out another way.

With most sensors, to get found out you have to do several things for a period of time before they activate or sense you. What you don't know is the crew rating of each escort, which determines the amount of sensor used.

[Raven Morpheus]

I share in neilbyrne's frustration with the AI. I run only the GFO mod (my other mods are graphical and sound related, so I believe they are unlikely to affect the AI).

I too find the AI to be clairvoyant.

My latest example of this is trying to do a "quick mission" provided by the GFO mod for the German side (the mission is called Ocean Danger).

You start off at least 6k away from a 4 merchant ship convoy with a 2 DD 3 armed trawler escort, at periscope depth and it's just getting to night time. I immediately upon starting the mission give the order to dive to what I think is under the thermal layer (90m or lower (I usually set 100m)), and sure enough on the way down I get the "passing thermal layer" message. All the time I'm either moving at half speed or less and trying to get into position.

When I am in position 9/10 times when I come up to periscope depth as soon as I take a look I can see that the AI has spotted me (in the dark!) and the 4 merchant ships in the target convoy have started to circle and seem to have been doing so for at least a few minutes because the convoy is all broken up?!

I've also had with the same mission the same thing neilbyrne gets - where a DD seems to automagically know where you are and starts depth charging you?!

Conversely so far in my US campaign I've not had such a problem, or at least not as much of a problem - perhaps that is because I've only done 2 missions and all the AI ships are set to the lowest value (Novice and below?) at the start of the campaign?


I really wish one of the talented modders out there would come up with a fix for this sort of clairvoyant behaviour, or if that's not possible perhaps a short guide to "best standard practice" could be written by one of the "experts" at not getting detected?