TDC and realistic playing

[Radio]

Atm I am playing the game (with my own megamod-soup) on nthe hardest settings, meaning no mapupdate, no targeting assistents etc. and I realized one thing:

The TDC is rather useless! The way one usually plays (with autopdate etc) the game gives you way too precise target data, however if you are using your own position marks and try to find the data yourself the TDC becomes virtually useless.

Why?

-During the day you will not be able to use the periscope w/o being detected.
-During the night you will not see the target good enough to get useful data
-If the weather is good your periscope is easier to see
-If the weather is bad it will ruin your target gathering procedures

This changed my way of getting target data and attacking completely.
The radar becomes the sensor of choice, followed by the active sonar, the later being restricted to targets w/o hydrophones, meaning that every warship and most late-war merchants can hear you etc.

It also slows down the attack speed, whereas you can normally (with map-updates) can use the 3 minute-rule to get target speed and course I now use a 30 minute rule with the radar.

It basically boils down to RockinRobbins/Dick O#Kane methods with some guestimating and more manoeuvering during th final attack phase. :DL

I can simply not see a way to use the TDC here in a practical manner.

What are your observations, do you have better ideas for the TDC "problem"? Or do you agree to my observation?

[TorpX]

I've never had that view. Manual TDC is certainly more difficult, but if you are willing to put in the extra time and effort in your approaches, you can do it.


The main difficulty in manual targeting is obtaining accurate data. This is often challanging, but is greatly aided by plotting out a good number of points and checking the data ('fairing' the plot). I would try to make 10 or 12 observations and use a rolling avg. of the last 3 to reduce the error of any single observation. Radar is a powerful tool and helps a lot, but is not indespensible to the process.

As far as the periscope goes, I found I was able to leave it up beyond 4,000yd. , but I tried to keep observations short as the range got down to 1,000yd. or so. Perhaps different mods change this aspect of the game?

[Rockin Robbins]

Unfortunately, no map updates, is not a realism setting, it is a difficulty setting. With no map updates you lose the plotting of radar contacts. The in-game radar is nowhere near as accurate as the real thing so you cannot plot radar contacts with any accuracy approaching the abilities of the real submarines.

In effect, the no map updates option is like learning to drive a car with a paper bag over your head, relying only on the verbal instructions of your passenger. It's a commendable skill. If you survive you surely have bragging rights. But it certainly has no application to a desirable way to drive.

Right now the most realistic way to do business in a submarine is the masterful TMO plotting system. It removes the target ID, course and speed text. It removes the hokey ship silhouettes and velocity vectors and shows contacts only as position points. You must develop course and speed. Even the MOST reliable part of visual targeting, estimated AoB, was no longer necessary. Targeting was now an empirical process.

It does, of necessity, leave exact position plotting of visually detected objects. Taking that away removes plotting of radar detected targets and attacking planes. It puts the paper bag over your head, killing more essential realistic information than its "improvement" is worth.

But everything else corresponds to what you would know as a real submarine. Why not just refuse to reduce visual positions to firing solutions? Develop all your firing data through radar and sonar. Then you are on solid realistic ground.

There is no realistic basis for map contacts off.

As far as your observations above:

I use my periscope during the day all the time without being detected. Keep periscope exposures of short duration. My limit during the daylight is 30 seconds. I am detected very infrequently.

Why do you concern yourself with the difficulty of obtaining visual data when you have radar and sonar? Radar was the gold standard for targeting in WWII. When Dick O'Kane lost his radar during a cruise, he shot off a bitter message to Pearl saying in effect "there goes half of my torpedoes, wasted!" That was the exact truth.

Radar for the very first time refined the targeting process further than educated guesswork. No longer was target identification, the least reliable parameter in targeting, essential to get visually targeted hits, even a part of the targeting process. Even the MOST reliable parameter, eyeballed AoB, was no longer necessary. Targeting had progressed from an art to an empirical process

[Arlo]

Unfortunately, no map updates, is not a realism setting, it is a difficulty setting. With no map updates you lose the plotting of radar contacts. The in-game radar is nowhere near as accurate as the real thing so you cannot plot radar contacts with any accuracy approaching the abilities of the real submarines.

In effect, the no map updates option is like learning to drive a car with a paper bag over your head, relying only on the verbal instructions of your passenger. It's a commendable skill. If you survive you surely have bragging rights. But it certainly has no application to a desirable way to drive.

Right now the most realistic way to do business in a submarine is the masterful TMO plotting system. It removes the target ID, course and speed text. It removes the hokey ship silhouettes and velocity vectors and shows contacts only as position points. You must develop course and speed. Even the MOST reliable part of visual targeting, estimated AoB, was no longer necessary. Targeting was now an empirical process.

It does, of necessity, leave exact position plotting of visually detected objects. Taking that away removes plotting of radar detected targets and attacking planes. It puts the paper bag over your head, killing more essential realistic information than its "improvement" is worth.

But everything else corresponds to what you would know as a real submarine. Why not just refuse to reduce visual positions to firing solutions? Develop all your firing data through radar and sonar. Then you are on solid realistic ground.

There is no realistic basis for map contacts off.

As far as your observations above:

I use my periscope during the day all the time without being detected. Keep periscope exposures of short duration. My limit during the daylight is 30 seconds. I am detected very infrequently.

Why do you concern yourself with the difficulty of obtaining visual data when you have radar and sonar? Radar was the gold standard for targeting in WWII. When Dick O'Kane lost his radar during a cruise, he shot off a bitter message to Pearl saying in effect "there goes half of my torpedoes, wasted!" That was the exact truth.

Radar for the very first time refined the targeting process further than educated guesswork. No longer was target identification, the least reliable parameter in targeting, essential to get visually targeted hits, even a part of the targeting process. Even the MOST reliable parameter, eyeballed AoB, was no longer necessary. Targeting had progressed from an art to an empirical process

Thank you, RR. This is good advice.

[Capt. Morgan]

I also find that the periscope is safe to use for extended periods if the target is at medium range or longer. At close range, you're limited to short observations, but by that time you should only need it to refine and verify your firing solution by checking what you observe against what the TDC/Position-Keeper says, and adjusting the TDC accordingly.

A good solution to the maps/no-maps contacts dilema is the Assisted Plotting Mod V1.4 (check the downloads section here). It removes all map contacts unless you hover the mouse cursor over the contact on the map - in which case you get a large circle to indicate the contact.

You can control at what zoom level this symbol first appears by editing the maps.cfg file in the mod (the SymbolZoom line IIRC). At a high enough zoom level, you can get a reasonable degree of inaccuracy in your plots, or you can set the zoom high enough that no symbols appear on the map at all. What you don't get is 100% accurate situational awareness the instant the periscope breaks the surface.

Aircraft contacts are similarly treated, but I believe that the radar of the day could only determine the range of an air contact and not the bearing, so this is not so great of a loss. You still get sonar contact lines.

If you use TMO 2X, your watch will report ranges to all contacts in feet! If this number is not directly divisable by 3, you can get some more imprecission when you convert to yards in your head (or at least I do when using my head).

I also like the OTC mod, which gives you calibrated periscope and TBT reticles. They allow you to calculate range and AOB by observation alone. The mod comes with a corrected and accurate ship ID book - if that bothers you, you can always ignore it and estimate the ships hight and length just like the real guys did,

[Rockin Robbins]

Real submariners didn't calculate AoB by observation alone unless they had radar. They eyeballed the target and used their experience to tell you what the AoB was. No measurement there at all.

[Capt. Morgan]

In that case, if for nothing else but training purposes, I recomend Aaron Bloods Electronic Plotting Board (http://www.subsim.com/radioroom/downloads.php?do=file&id=648)

It has a feature which gives you a zoomable periscope view of a freighter which you can rotate, and then guess the A.O.B. Clicking a button gives you the correct figure.

[Rockin Robbins]

Arrrrr! See the animated MoBo logo on my siggy pic? There's a reason for that. :D

[Radio]

Many thanks for the answers, guys. You really helped me a lot. My campaign continued (before I read these tips) and I now am rather good at getting a target course and speed with radar. It is incredibly accurate and error-tolerant when you use longer time-spans between the measurements, that way you can even track the target in real-time, no need for frantic PAUSE-F3-Click-UNpause etc sessions anymore. :DL

I will try the mods you recommended, they sure sound like a big improvement!

Talking about error-tolerant (a word I heard in your great video tutorials, RockinRobbins): I always wondered why EXACTLY the Dick'O'Kane method is so tolerant and after some calculating and drawing on a piece of paper I found the reason: The target is in such a good position (90 degree angle and close), the method simply maximizes the area that you can hit. At close ranges (<750yd) you have a incredibly huge field/spread angle that will still hit the target no matter what happens. OK disregarding major faults of course... and if you shoot several torpedoes it is almost a 100% hit and maybe even a kill.

I am having fun here as you can maybe tell.


Ok thanks to everyone and keep on sinking them! :up:


p.s. regarding the MoBo: I made myself a Vector attack "board" (a simple piece of paper actually) and use it to quickly measure my lead angle when shooting as I simply grew tired of drawing the vectors in SH4's navmap. NO need for lists or anything, I simply measure the angle (with a protractor if that's the correct word) between two distances on the piece of paper where I marked important things like 46 knots, 29 knots etc and get the needed lead angle in a split-second... Geeky, I know, but I am a geek, so what?

[timmyg00]

I tried using the TDC with radar data (no map contacts; OTC mod and 3D TDC and RRU enabled)... my radar data was spot-on, because the target was not zig-zagging and maintained constant speed and course. I input my data into the TDC, and all my fish missed astern. I've had so much success with the Dick O'Kane method that I immediately went back to that instead of using the TDC. However, I've always wanted to figure out where I went wrong with entering the data into the TDC, so i could use the real O'Kane method...

Perhaps another reading of the OTC and 3D TDC/RRU mod instructions is in order, but if anyone has any advice, I'd welcome it.

TG

[Rockin Robbins]

See the posts in the Sub Skippers' Bag of Tricks thread where I discuss the importance of the order information is input into the TDC. Nobody talks about it, it's not mentioned in any manual anywhere, but order of input is vitally important.

How do you know you are doing it wrong? You miss astern.

[Daniel Prates]

Nobody talks about it, it's not mentioned in any manual anywhere, but order of input is vitally important.



Specially so in SH3, where manual targeting and data input procedures are not well worked-out as in SH4.

[Radio]

I tried using the TDC with radar data (no map contacts; OTC mod and 3D TDC and RRU enabled)... my radar data was spot-on, because the target was not zig-zagging and maintained constant speed and course. I input my data into the TDC, and all my fish missed astern. I've had so much success with the Dick O'Kane method that I immediately went back to that instead of using the TDC. However, I've always wanted to figure out where I went wrong with entering the data into the TDC, so i could use the real O'Kane method...

Perhaps another reading of the OTC and 3D TDC/RRU mod instructions is in order, but if anyone has any advice, I'd welcome it.

TG


Same here, TDC = miss, O'Kane = kill :DL


Anyway, I did include the mods you guys recommended (e.g. no-icons etc) to my mega-mod-soup and now I am back to Mapudate ON and the game starts to feel complete. :up:

One thing I learned when using "manual" radar is that you have to use the right-most bearing from a target on the A-scope to get the exact position. The target usually "stretches" over a 4 to 5 degrees detection area in the Ascope. If you use the center then you will have inprecise data to work with, always use the right side (as right as you can go w/o losing the contact).

[CapnScurvy]

I tried using the TDC with radar data (no map contacts; OTC mod and 3D TDC and RRU enabled)... my radar data was spot-on, because the target was not zig-zagging and maintained constant speed and course. I input my data into the TDC, and all my fish missed astern. I've had so much success with the Dick O'Kane method that I immediately went back to that instead of using the TDC. However, I've always wanted to figure out where I went wrong with entering the data into the TDC, so i could use the real O'Kane method...

Perhaps another reading of the OTC and 3D TDC/RRU mod instructions is in order, but if anyone has any advice, I'd welcome it.

TG


I've got a question?
You're using "Optical Targeting Correction" for a stock 1.5 game.
The "3D TDC & Radar Range Unit v1.02"
And something called "RRU"? (Guess I need to get out more)

If that's right, I should point out that the "3D TDC" mod overwrites some of the files of OTC that permit the PPI radar screen to function correctly. Neither the range accuracy, or the capabilities of the corrected radar sensitivity/detection function will work as intended from the OTC mod. 3D TDC & Radar Range Unit v1.02 changes the A-scope but does not accurately modify the PPI. Nor does it work on all sub classes.

OTC reworks both A-scope and PPI radar for accurate reading (as much as the "scale" overlays permit) and changes the sensitivity/detection abilities of the radar to allow for not only better surface ship finding but aircraft detection as well. I'm not saying which is better, but I do want to point out that adding the 3D TDC mod over top of OTC will not give you the results you may expect.

As far as your missing a target astern, you may have had the correct range and target track (AoB) inputted. The third factor, target speed, could have been the major reason for the miss. Inputting a targets speed short of what it actually was going will cause a stern miss every time.

Of course, you can use the Dick O'Kane method and stick your nose up the target's butt, so close that you can't miss. I remember watching on a Sunday morning a guy named Oswald take a "gut shot" in Dallas Texas on live TV. Don't need to know anything else than how to pull a trigger to get the job done.

[CptChacal]

I know this has been discussed ad nauseam before, but even using the TDC is more a question of difficulty than realism, because you're basically doing the XO's* job in addition to the CO's job. If you also add plotting and navigation, you're doing the job of many officers.

Automatic targeting is probably more realistic for the CO's job, but a lot less fun.

* or another specialist, depending on the CO's decision.

[Radio]

True. But I also like to shoot the deckgun and AA manually, so... :DL

Atm I changed sides and am controlling a Type IX in the OM mod, that KiUB interface.... well let's say it this way: The american TDC seems dead-simple now! :DL

It took me three days before I could FULLY understand and use the new german AOBF.... I think when I gonna return to the american campaign I will no longer have ANY problems with the TDC at all!

[Rockin Robbins]

There are no style points in war. Whether you shot from 3,000 yards or "your nose up the target's butt" nobody cares. They care about whether your torpedoes put enemy boats on the bottom and how efficiently that was done. No matter how it's done, the long range shot is less likely to succeed.

It's not as "skillful." Tough toenails! If I have to put my nose up the target's butt to make sure they're dead and I'm above room temperature, I don't care about how skillful it is to miss 'em from 3,000 and then get killed. I'll take the unfair shot every time. This is war, not a freakin' square dance.

If I have my way every single shot will be from so close my grand-ma-ma couldn't miss and she's dead. If I ever find myself in a fair fight I'll run away because I screwed the pooch by not planning that one right. Chivalry my achin' butt...:D
http://i196.photobucket.com/albums/aa293/RockinRobbins13/smileys/11piratas-pirates.gif

[Arlo]

There are no style points in war. Whether you shot from 3,000 yards or "your nose up the target's butt" nobody cares. They care about whether your torpedoes put enemy boats on the bottom and how efficiently that was done. No matter how it's done, the long range shot is less likely to succeed.

It's not as "skillful." Tough toenails! If I have to put my nose up the target's butt to make sure they're dead and I'm above room temperature, I don't care about how skillful it is to miss 'em from 3,000 and then get killed. I'll take the unfair shot every time. This is war, not a freakin' square dance.

If I have my way every single shot will be from so close my grand-ma-ma couldn't miss and she's dead. If I ever find myself in a fair fight I'll run away because I screwed the pooch by not planning that one right. Chivalry my achin' butt...:D
http://i196.photobucket.com/albums/aa293/RockinRobbins13/smileys/11piratas-pirates.gif

I musta missed the 'chivalry' part of the discussion. I see two different skill sets represented and admire them both. One is the skill it takes to get that close without detection and the other is the skill to set up a sniper shot that hits it's mark. I've gotten to within 1k of a juicy TF flagship twice and virtually survived (midnight and choppy seas). The whole dang Japanese navy out to get me. But then, I've had them swarm me from a shot made at 6k (on a calm sunny day).

[Rockin Robbins]

Don't mind me, I'm just rattlin' me sabre!:arrgh!:

[0rpheus]

True. But I also like to shoot the deckgun and AA manually, so... :DL

Atm I changed sides and am controlling a Type IX in the OM mod, that KiUB interface.... well let's say it this way: The american TDC seems dead-simple now! :DL

It took me three days before I could FULLY understand and use the new german AOBF.... I think when I gonna return to the american campaign I will no longer have ANY problems with the TDC at all!

Too right.. took me ages to get the hang of the US TDC, and I still fluff those shots occasionally. Loaded up OM with OMEGU last night, took a look at the KiUB interface instructions....

no way in hell am I doing all that! Shame really as it loses something not targeting yourself, but it took long enough to get the hang of the US TDC. The OM one is just too much!:haha:

[Daniel Prates]

If radar was that indispensable, how do we explain the high rate of success experimented by the germans all through the war, since uboats were not equiped with such devices (except towards the end where some uboats started using radars)?

Radar is a tool useful for finding and screening targets at long distances. Since in most situations you have to be underwater to be close enough to fire, obviously the visual method has to be the first choice. Now, there is no question that it is hard and imprecise sometimes, but it is the best tool available. Regarding AOB, from what I read here, a purely visual guessing was the method of choice! So it's all about refining your analogic techiniques...

[joea]

Daneil, I would dispute the fact Germans had high rates of success through the whole war. Early war, yes for sure, mid-war, a lot less. 43 on they often didn't even get close as they were kept down by .... radar equipped Allied ships and aircraft.

Early was neither side in the Atlantic was equipped with radar, except some capital ships. Definately no air assets had it either. So the u-boats could do quite well with visual tracking.

[Rockin Robbins]

If radar was that indispensable, how do we explain the high rate of success experimented by the germans all through the war, since uboats were not equiped with such devices (except towards the end where some uboats started using radars)?

Radar is a tool useful for finding and screening targets at long distances. Since in most situations you have to be underwater to be close enough to fire, obviously the visual method has to be the first choice. Now, there is no question that it is hard and imprecise sometimes, but it is the best tool available. Regarding AOB, from what I read here, a purely visual guessing was the method of choice! So it's all about refining your analogic techiniques...

First of all, the Germans did not have a high rate of success. They just had a lot of U-Boats out there, most of which never sank a single target. Only 10 percent of them had the lion's share of the tonnage sunk. The statistics on the number of U-Boats sunk having never fired a torpedo in action is just astounding.

What success they had was due to their numbers and the lack of any coordinated anti-submarine tactics early in the war. Once the British perfected how destroyers and planes were to be handled, the sub war was just about over. Then Admiral Daniel Gallery came on the scene with his jeep carrier hunter-killer groups and the nails were all in the coffins. Predictably, the U-Boats were unable to be a decisive influence on the war, aside from the colossal waste of men and resources the Germans flushed down the drain to use a weapon unable to help their cause.

For better or worse, the Germans were entirely dependent on their land-based warfare for any success they were going to have. Anything (read Navy) that subtracted from their land based assets hurt their war effort. The U-Boats did worse than that, sucking the US into the war and guaranteeing complete German defeat.

Once the American boats had radar, THEN deducing AoB from radar plot was more accurate than visual estimate and they used that number. With visual targeting, the AoB estimate was the MOST reliable number they had. When you are analyzing, you always deduce more doubtful numbers based on your most reliable ones. That is what many of the targeting gurus on Subsim have forgotten and why their methods were not used during the war.

These guys in the war were as smart as we are. There's nothing we've thought of that they didn't. If they didn't time ship length by the wire to obtain speed, and they did not, there is a good reason. That is that target identification and actual target lengths were among the least reliable of their information. It would have been foolishness to try to calculate anything based on defective data. So they didn't.

[Barkhorn1x]

Back after a spell.

Hey Rockin', how goes it?

I use the Dick O'Kane method because the TDC range estimating/AOB is so fiddy.

DO gives you a method that works and works well - w/ an accurate AOB and no range needed. It's simple, elegant, realistic and it works.

[TorpX]

Once the American boats had radar, THEN deducing AoB from radar plot was more accurate than visual estimate and they used that number. With visual targeting, the AoB estimate was the MOST reliable number they had. When you are analyzing, you always deduce more doubtful numbers based on your most reliable ones. That is what many of the targeting gurus on Subsim have forgotten and why their methods were not used during the war.


Obtaining AOB from radar plot works well provided your target is not zigging. We don't have to worry too much about that, but the USN had thinking opponents to contend with. O'Kane made full use of radar AND made visual estimates of AOB. Why? Because, using radar alone, one can obtain the base course of the target, and the general nature and form of past zig-zags, but not the timing or heading of next one. Good estimation of the AOB allows one to see quickly that the target is starting (or has already started) another leg, and what the new course is.

These guys in the war were as smart as we are. There's nothing we've thought of that they didn't. If they didn't time ship length by the wire to obtain speed, and they did not, there is a good reason. That is that target identification and actual target lengths were among the least reliable of their information. It would have been foolishness to try to calculate anything based on defective data. So they didn't.

I can't argue with you there. :)

[timmyg00]

I've got a question?
You're using "Optical Targeting Correction" for a stock 1.5 game.
The "3D TDC & Radar Range Unit v1.02"
And something called "RRU"? (Guess I need to get out more)

If that's right, I should point out that the "3D TDC" mod overwrites some of the files of OTC that permit the PPI radar screen to function correctly. Neither the range accuracy, or the capabilities of the corrected radar sensitivity/detection function will work as intended from the OTC mod. 3D TDC & Radar Range Unit v1.02 changes the A-scope but does not accurately modify the PPI. Nor does it work on all sub classes.

OTC reworks both A-scope and PPI radar for accurate reading (as much as the "scale" overlays permit) and changes the sensitivity/detection abilities of the radar to allow for not only better surface ship finding but aircraft detection as well. I'm not saying which is better, but I do want to point out that adding the 3D TDC mod over top of OTC will not give you the results you may expect.

As far as your missing a target astern, you may have had the correct range and target track (AoB) inputted. The third factor, target speed, could have been the major reason for the miss. Inputting a targets speed short of what it actually was going will cause a stern miss every time.

Of course, you can use the Dick O'Kane method and stick your nose up the target's butt, so close that you can't miss. I remember watching on a Sunday morning a guy named Oswald take a "gut shot" in Dallas Texas on live TV. Don't need to know anything else than how to pull a trigger to get the job done. Thanks, i will look at the difference between them and see which one i like better!

TG

[timmyg00]

See the posts in the Sub Skippers' Bag of Tricks thread where I discuss the importance of the order information is input into the TDC. Nobody talks about it, it's not mentioned in any manual anywhere, but order of input is vitally important.

How do you know you are doing it wrong? You miss astern.
Thanks... been looking there, used the search function... couldn't find it. I know i've seen somebody talk about that somewhere...


TG

[mobucks]

not sure but my best guess would be
speed/aob/range then quickly turn on the PK

[Sailor Steve]

These guys in the war were as smart as we are.
And a whole lot better trained. I went through 12 weeks of school just to learn how to operate the fraggin' radios. The officers did a lot more than that before they were ready to be officers, and a whole lot more than that before they were ready to be submarine officers.

[Barkhorn1x]

And a whole lot better trained. I went through 12 weeks of school just to learn how to operate the fraggin' radios. The officers did a lot more than that before they were ready to be officers, and a whole lot more than that before they were ready to be submarine officers.


Excellent point; they didn't exactly:
- Buy the game
- Have trouble w/ W7 UAC
- Finally get the game to work
- Ask questions in the forum
- Get answers, view stickied threads and watch some YouTube videos

...then; "Look at me, I'm a World War II sub commander!"

[Daniel Prates]

First of all, the Germans did not have a high rate of success. They just had a lot of U-Boats out there, most of which never sank a single target. Only 10 percent of them had the lion's share of the tonnage sunk. The statistics on the number of U-Boats sunk having never fired a torpedo in action is just astounding.

What success they had was due to their numbers and the lack of any coordinated anti-submarine tactics early in the war. Once the British perfected how destroyers and planes were to be handled, the sub war was just about over. Then Admiral Daniel Gallery came on the scene with his jeep carrier hunter-killer groups and the nails were all in the coffins. Predictably, the U-Boats were unable to be a decisive influence on the war, aside from the colossal waste of men and resources the Germans flushed down the drain to use a weapon unable to help their cause.

For better or worse, the Germans were entirely dependent on their land-based warfare for any success they were going to have. Anything (read Navy) that subtracted from their land based assets hurt their war effort. The U-Boats did worse than that, sucking the US into the war and guaranteeing complete German defeat.

Once the American boats had radar, THEN deducing AoB from radar plot was more accurate than visual estimate and they used that number. With visual targeting, the AoB estimate was the MOST reliable number they had. When you are analyzing, you always deduce more doubtful numbers based on your most reliable ones. That is what many of the targeting gurus on Subsim have forgotten and why their methods were not used during the war.

These guys in the war were as smart as we are. There's nothing we've thought of that they didn't. If they didn't time ship length by the wire to obtain speed, and they did not, there is a good reason. That is that target identification and actual target lengths were among the least reliable of their information. It would have been foolishness to try to calculate anything based on defective data. So they didn't.

Well then, I stand corrected... :doh:

I wasn't thinking about objective data, actually, as indeed the sub vs ship score does not compare to a basketball game - obviously. In that sense, yeah, not successful. I was refering to the fact that u-boats were perceived as a serious threath, dragged a lot of resources to counter them, and is mentioned in some moments as being near to turn comercial shipping inviable, during the first half of the war.

All that without radar. I recall this thread being about radar being indispensable for a minimally-usefull submarine, a thing that the german experience shows otherwise. That's all.

[commandosolo2009]

Atm I am playing the game (with my own megamod-soup) on nthe hardest settings, meaning no mapupdate, no targeting assistents etc. and I realized one thing:

The TDC is rather useless! The way one usually plays (with autopdate etc) the game gives you way too precise target data, however if you are using your own position marks and try to find the data yourself the TDC becomes virtually useless.

Why?

-During the day you will not be able to use the periscope w/o being detected.
-During the night you will not see the target good enough to get useful data
-If the weather is good your periscope is easier to see
-If the weather is bad it will ruin your target gathering procedures

This changed my way of getting target data and attacking completely.
The radar becomes the sensor of choice, followed by the active sonar, the later being restricted to targets w/o hydrophones, meaning that every warship and most late-war merchants can hear you etc.

It also slows down the attack speed, whereas you can normally (with map-updates) can use the 3 minute-rule to get target speed and course I now use a 30 minute rule with the radar.

It basically boils down to RockinRobbins/Dick O#Kane methods with some guestimating and more manoeuvering during th final attack phase. :DL

I can simply not see a way to use the TDC here in a practical manner.

What are your observations, do you have better ideas for the TDC "problem"? Or do you agree to my observation?

The TDC is just a prediction device people. Its not designed to be the attack method of choice. It just provides an old era target point estimation provided the target doesnt detect you, which means, you havent been spotted.

Further, if you complain of a damaged TDC, you should know that experienced sailors eyes IRL, were the most accurate. As a proof, the submariner doesnt follow the TDC, the TDC follows his input. And at some point in time, if the target happens to be where its supposed to be, then the TDC did its job, and the data collection was flawless. But that wasnt the issue in the great war. It was the defective torpedoes that BuOrd issued to the navy, that at some point, one guy looking at an abacus counting sunk ships over a period of time, were too few for the torpedoes issued. And this instigated an inquiry by Lockwood, who discovered the defects and ordered contact pistol by defualt for the remainder of the war.

Maybe you know the info above, maybe you dont. But my point is, TDC is a checking device, not a targeting device. I doubt in harbor raids that they even turned it on... Not this clownish stuff we do in a sim..

[Arlo]

http://en.wikipedia.org/wiki/Target_Data_Computer

http://upload.wikimedia.org/wikipedia/commons/thumb/0/0a/TDCfullview.jpg/220px-TDCfullview.jpg

The TDC was designed to provide fire-control solutions for submarine torpedo (http://en.wikipedia.org/wiki/Torpedo) launches against ships (http://en.wikipedia.org/wiki/Ship) running on the surface (surface warships used a different computer for their torpedo launches).[4] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-3) The TDC had a wide array of handcranks, dials and switches for data input and display.[5] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-4) To generate a fire control solution, it required inputs on

submarine course and speed, which were read automatically from the submarine's gyrocompass (http://en.wikipedia.org/wiki/Gyrocompass) and pitometer log (http://en.wikipedia.org/wiki/Pitometer_log)
estimated target course, speed, and range information (obtained using data from the submarine's periscope (http://en.wikipedia.org/wiki/Periscope), Target Bearing Transmitter (http://en.wikipedia.org/w/index.php?title=Target_Bearing_Transmitter&action=edit&redlink=1),[6] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-5) radar (http://en.wikipedia.org/wiki/Radar), and sonar (http://en.wikipedia.org/wiki/Sonar))
torpedo type and speed (type was needed to deal with the different torpedo ballistics)
The TDC performed the trigonometric (http://en.wikipedia.org/wiki/Trigonometry) calculations required to compute a target intercept course for the torpedo. It also had an electromechanical interface to the torpedoes that allowed it to automatically set the torpedo courses while they were in their tubes, ready to be launched.
The TDC's target tracking capability was used by the fire control party to continuously update the fire control solution to the torpedoes even while the submarine was maneuvering. The TDC's target tracking ability also allowed the submarine to accurately launch torpedoes even when the target was temporarily obscured by smoke or fog.



TDC functional description

Since the TDC actually performed two separate functions, generating target position estimates and computing torpedo firing angles, the TDC actually consisted of two types of analog computers:

Angle solver: This computer calculates the required gyro angle. The TDC had separate angle solvers for the forward and aft torpedo tubes.
Position keeper: This computer generates a continuously updated estimate of the target position based on earlier target position measurements.[35] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-positionkeeper-34)
[edit (http://en.wikipedia.org/w/index.php?title=Torpedo_Data_Computer&action=edit&section=5)] Angle solver

The equations implemented in the angle solver can be found in the Torpedo Data Computer manual.[36] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-tdcv3-35) The Submarine Torpedo Fire Control Manual[37] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-tdc-36) discusses the calculations in a general sense and a greatly abbreviated form of that discussion is presented here.

The general torpedo fire control problem is illustrated in Figure 2. The problem is made more tractable if we assume:

The periscope is on the line formed by the torpedo running along its course
The target moves on a fixed course and speed
The torpedo moves on a fixed course and speed
http://upload.wikimedia.org/wikipedia/commons/thumb/2/2f/Intercept.png/220px-Intercept.png (http://en.wikipedia.org/wiki/File:Intercept.png) http://bits.wikimedia.org/skins-1.18/common/images/magnify-clip.png (http://en.wikipedia.org/wiki/File:Intercept.png)
Figure 3: The Torpedo Fire Control Triangle


As can be seen in Figure 2, these assumptions are not true in general because of the torpedo ballistic characteristics and torpedo tube parallax. Providing the details as to how to correct the torpedo gyro angle calculation for ballistics and parallax is complicated and beyond the scope of this article. Most discussions of gyro angle determination take the simpler approach of using Figure 3, which is called the torpedo fire control triangle.[7] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-clear-6)[8] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-wahoo-7) Figure 3 provides an accurate model for computing the gyro angle when the gyro angle is small, usually less than < 30o.[38] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-SmallGyro-37)
The effects of parallax and ballistics are minimal for small gyro angle launches because the course deviations they cause are usually small enough to be ignorable. U.S. submarines during World War II preferred to fire their torpedoes at small gyro angles because the TDC's fire control solutions were most accurate for small angles.[39] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-Doctrine-38)
The problem of computing the gyro angle setting is a trigonometry problem that is simplified by first considering the calculation of the deflection angle, which ignores torpedo ballistics and parallax.[40] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-Deflection-39) For small gyro angles, ***952;Gyro ***8776; ***952;Bearing - ***952;Deflection. A direct application of the law of sines (http://en.wikipedia.org/wiki/Law_of_sines) to Figure 3 produces Equation 1.
(Equation 1)
http://upload.wikimedia.org/wikipedia/en/math/2/5/0/250aafe4a1cabef37bddfaa57f0ef92f.png
where
vTarget is the velocity of the target.vTorpedo is the velocity of the torpedo.***952;Bow is the angle of the target ship bow relative to the periscope line of sight.***952;Deflection is the angle of the torpedo course relative to the periscope line of sight.Range plays no role in Equation 1, which is true as long as the three assumptions are met. In fact, Equation 1 is the same equation solved by the mechanical sights of steerable torpedo tubes (http://www.history.navy.mil/photos/images/h41000/h41761.jpg) used on surface ships during World War I and World War II. Torpedo launches from steerable torpedo tubes meet the three stated assumptions well. However, an accurate torpedo launch from a submarine requires parallax and torpedo ballistic corrections when gyro angles are large. These corrections require knowing range accurately. When the target range was not known, torpedo launches requiring large gyro angles were not recommended.[41] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-AccurateRange-40)
Equation 1 is frequently modified to substitute track angle for deflection angle (track angle is defined in Figure 2, ***952;Track=***952;Bow+***952;Deflection). This modification is illustrated with Equation 2.
(Equation 2)
http://upload.wikimedia.org/wikipedia/en/math/5/6/a/56ae291005170acc39729edc1ebc2bba.png

where
***952;Track is the angle between the target ship's course and the torpedo's course.http://upload.wikimedia.org/wikipedia/commons/thumb/c/c1/DeflectionAngle.png/220px-DeflectionAngle.png (http://en.wikipedia.org/wiki/File:DeflectionAngle.png) http://bits.wikimedia.org/skins-1.18/common/images/magnify-clip.png (http://en.wikipedia.org/wiki/File:DeflectionAngle.png)
Figure 4: Deflection Angle Versus Track Angle and Target Speed (***952;Gyro = 0o).


A number of publications[42] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-OptimumTrackAngle-41)[43] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-Clear2-42) state the optimum torpedo track angle as 110o for a Mk 14 (46 knot weapon). Figure 4 shows a plot of the deflection angle versus track angle when the gyro angle is 0o (i.e., ***952;Deflection=***952;Bearing).[44] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-track-43) Optimum track angle is defined as the point of minimum deflection angle sensitivity to track angle errors for a given target speed. This minimum occurs at the points of zero slope on the curves in Figure 4 (these points are marked by small triangles).
The curves show the solutions of Equation 2 for deflection angle as a function of target speed and track angle. Figure 4 confirms that 110o is the optimum track angle for a 16-knot (30 km/h) target, which would be a common ship speed.[45] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-TargetSpeed-44)
There is fairly complete documentation available for a Japanese torpedo fire control computer that goes through the details of correcting for the ballistic and parallax factors (http://home.comcast.net/~mbiegert/Work/HistOfTech/TDC/Model.htm). While the TDC may not have used exactly the same approach, it was likely very similar.
[edit (http://en.wikipedia.org/w/index.php?title=Torpedo_Data_Computer&action=edit&section=6)] Position keeper

As with the angle solver the equations implemented in the angle solver can found in the Torpedo Data Computer manual.[36] (http://en.wikipedia.org/wiki/Target_Data_Computer#cite_note-tdcv3-35) Similar functions were implemented in the rangekeepers for surface ship-based fire control systems. For a general discussion of the principles behind the position keeper, see Rangekeeper (http://en.wikipedia.org/wiki/Rangekeeper).

[Muty]

Hey guys thanks for the outstanding info you posted here. You answered some of the questions that were bothering me for years.

[berobispo]

I have become a big fan of the position keeper since I installed the Optical targeting correction mod (OTC). It has a 1-degree bearing periscope/TBT, this way you can compare generated bearing with observed ones very well. Even if your solution still lags 1 degree every 2 minutes for example and you aim for a torpedo run of 2 minutes, simply set a 1 degree forward angle in the torpedo settings.

For spreads I use Hitman's ingame torpedo spread angle calculator.

There still is the bug with the AoB updating/not updating when a new range is sent, but I have built a wiz-wheel to know exactly which AoB to enter for any observed bearing and assumed enemy course. My best shot so far was a MOT (from a spread of two, the MOT actually went underneath because of faulty depth setting, one missed) on a transiting DD going 12kts with a MK14 torpedo run of 6:30 minutes (slow speed setting).

[Daniel Prates]

I have become a big fan of the position keeper since I installed the Optical targeting correction mod (OTC).

It is great, isnt't it?