Stranger than you CAN imagine

[Rockin Robbins]

I think it was Issac Asimov who said that the universe was not only stranger than we believe but stranger than we CAN believe. Follow me into the twilight zone.

We have long been using Dick O'Kane with the instruction, bearing set, range who cares? But because of the short distance the torpedo travels straight out of the tube before it turns to the set bearing, a distance called reach, a slight angle is created from the apparent origin of the torpedo's path and the position of our submarine when the torpedo is fired. That means that the range in the TDC actually is meaningful even in a point and shoot shot....

Yeah, that's what I said too. OK, how bad can this get? Can't be too bad, right? So I set up an 8000 yard shooting gallery with tankers arrayed about every 10 degrees, with the center one on the zero bearing. Let's make boom-booms! This is MY kind of experimentation.

Through this whole thing I am using slow speed torpedoes for max range. Stupid me!

First, let's send six torpedoes up the zero line. We'll fire two on the default zero range, two on 3475, the manual setting I always use for Dick O'Kane, set 2 for 3000 and 2 for 8000 yards. Shoot times six!

Nasty finding number one! Of six torpedoes shot, only two reached 8000 yards. The rest crapped out between 3000 and 4500 yards. Also the torpedoes all ran different speeds, making spacing really important to tell which torpedoes were which. Which ones reached the target? I don't know. Set 'em up again.

This time I shot only the first two, set at zero range, up the zero line 30 seconds apart. They both made 8000 yards this time and they......both......missed right by about a target length and a half. What the?????:doh: Tried if again and again. When the torpedoes reached the 8000 yards (about half the time) they all missed right. These are zero gyro angle shots! Somehow the zero range predictable alters the path to the right far enough to miss consistently at 8000 yards. Play the scary music.

Any other range went up the zero line and struck the target if the torpedo got that far. I learned that experimenting at 8000 yards was darn frustrating and I'd better shorten up the shooting gallery. So I did.

I set up a new one at 3200 yards with target tankers on the 315, 320. 334, 346, 0, 14, 24, 35 and 49 bearings. That is more like it! I sent three torpedoes up the zero line with 1475, 2650 and 5008 ranges. What do you think happened?

http://i196.photobucket.com/albums/aa293/RockinRobbins13/Silent%20Hunter%204/Manual%20TDC%20Range/0deg3200ydset140026255008.jpg

Well that was refreshingly expected. They were very similar in path and all struck pretty much the identical spot.

Now let us leave the bounds of sanity and enter the darker realms. We'll aim at the 49º bearing boat. What happens with a shot set to 9843 yards?

http://i196.photobucket.com/albums/aa293/RockinRobbins13/Silent%20Hunter%204/Manual%20TDC%20Range/50deg3200ydset9843.jpg

It's a clean miss! The torpedo goes straight to the end of its reach, turns right but stops turning early so that 9843 yards it crosses the set bearing. Anywhere before there it's going to miss left by varying amounts depending on the distance traveled. So what ARE the allowable parameters at 3200 yards? I decided to find out by experimentation with the game, since a mathematical proof does not have to hold true there, especially after the zero bearing zero range shot consistently missed right earlier. I need a drink. NOW!

Turns out that a range of 5582 yards will just clip the left end of the target.

http://i196.photobucket.com/albums/aa293/RockinRobbins13/Silent%20Hunter%204/Manual%20TDC%20Range/50deg3200ydset5582.jpg

Of course, the correct range nails it

http://i196.photobucket.com/albums/aa293/RockinRobbins13/Silent%20Hunter%204/Manual%20TDC%20Range/50deg3200ydset3251.jpg

And 2625 clips the right end.

http://i196.photobucket.com/albums/aa293/RockinRobbins13/Silent%20Hunter%204/Manual%20TDC%20Range/50deg3200ydset2625.jpg

So there you have it. For a target sitting at bearing 49º the margin of error for this tanker was -575 to +2382 yards, 80% to 174% of the actual range would hit the target. Lesser deviations from zero bearing would be more tolerant, greater bearings would be even less tolerant to proper range being input into the TDC.

The conclusions we can make here are the following. Don't shoot Dick O'Kane shots from more than 2000 yards, with torpedo gyro angles much above 15º left or right. Between 345 and 15, you'll get your hits. Outside that you better put a rough range estimate into the TDC. There's plenty of slop, but the more accurate the better.

Inside of 2000 yards don't change a thing. You're a deadeye killer there. Proceed as normal. Of course you realize that one sonar ping will peg that range close enough for anybody's liking and you can shoot out to 3000 yards with perfect accuracy. Well not perfect but nobody on the target will care that the shot landed ten yards off the aiming point.

And don't bother shooting beyond 3000 yards with the stock game. Half the slow speed torpedoes run out of juice between 3000 and 4000 yards. You can't sink ships with a wimpy torpedo. Luke, what about RFB? Ducimus is in the slammer, so does anybody know the score with TMO?

Want to play? Here's my 3200 Yard Shooting Gallery (http://dodownload.filefront.com/12136727//ebfdaaa4f70ad475238889fc2693d025a685a12137f6a368ab d7aed6a9953e9b0690bdc034c1d611) for your listening and dancing enjoyment. Unzip into your Wolves of the Pacific\data\single missions folder.

[Arclight]

Haha, told you range was relevant. :p

Nice write up. ;)

[Sledgehammer427]

and thats why i hate broad angles...

hey Rockin Robbins...i need some help with a term paper :rotfl:
just kidding

[Rockin Robbins]

and thats why i hate broad angles...

hey Rockin Robbins...i need some help with a term paper :rotfl:
just kidding

Man! I was thinking that I had finally written something that NOBODY cared about.

Arclight, the general principle still holds. If you're shooting under 2000 yards, that's all but about 3 of my shots ever, it really doesn't matter so long as you pull the triangle down and have the normal 1475 yards in the system. If you're shooting 3000 yards or more, find a way to put 3000 yards in the TDC. That's close enough.

If you're shooting 4000 yards or more it doesn't matter because half your torpedoes aren't getting there anyway.:rotfl: That was the real shocker for me.

[Arclight]

I know it doesn't really matter. I'm just a perfectionist, so I couldn't resist. :lol: ;)

I always set the range as high as I can get it (requires some fidling with the stadimeter). Then the "deviation" is never more then the distance the tubes are from the centerline (at least when firing at 0 bearing :-?). At first I set the range as low as it would go, but then you notice the issue when firing at longer ranges.

Like you suggested, a quick ping for range will solve the issue.


But I never noticed torpedo's running out of steam too early. :hmm:
Longest (RFB) shot for me was 4 fish running more then 6000 yards, with 2 hits and actually detonating, the other 2 going in front and behind the target.

Was this while you were testing the new RFB?

[Orion2012]

I know it doesn't really matter. I'm just a perfectionist, so I couldn't resist. :lol: ;)

I always set the range as high as I can get it (requires some fidling with the stadimeter). Then the "deviation" is never more then the distance the tubes are from the centerline (at least when firing at 0 bearing :-?). At first I set the range as low as it would go, but then you notice the issue when firing at longer ranges.

Like you suggested, a quick ping for range will solve the issue.


But I never noticed torpedo's running out of steam too early. :hmm:
Longest (RFB) shot for me was 4 fish running more then 6000 yards, with 2 hits and actually detonating, the other 2 going in front and behind the target.

Was this while you were testing the new RFB?

If it was I've had a few fail to start, or the motor dies before they reach 100 yards, but haven't really shot over 1800 yards.

Those pictures though aren't from the RFB 1.52 unless RR is using a HUD overhaul.

[Sledgehammer427]

that gui looks like TMO...
the PK button would have GSP labeled on it if it were RFB

[Skyhawk]

"Man! I was thinking that I had finally written something that NOBODY cared about." -RR-

LOL @ RR, you'd be surprised! :yep: :rotfl:

"Much Ado About Nothing" mean anything? Ring any bells? :hmm:

Now, to make sure I understand correctly:

You mean to say that the O'Kane method of torpedo firing solutions is less than accurate at long ranges?

That torpedoes both real and simulated sometimes fail to perform to specs?

And speaking of "reach", while we are mixing simulated reality with reality itself . . .

What about the effect of ocean currents on a 1.5 mile / 8,000 yd. shot? Or a 4,000 yd. shot?

What about the effect of wave action on a 1.5 mile / 8,000 yd. shot? Or a 4,000 yd. shot?

You mean to say, that even though the O'Kane method of torpedo firing solutions is highly reliable, that it is not foolproof at extreme/long range?

Wow, who woulda thunk? I can't imagine!

longshot - 1. an entry, as in a horse race, with only a slight chance of winning. 2 a. bet made at and against great odds. b. A risky venture that will pay off handsomely if successful.

Maybe that's why they call them "longshots"? Geeze Louise, lol.

Thank you for enlightening us oh mighty "Self-Proclaimed and Self-Righteous Protector of the Subsim Forums". Here's hoping your sense of humor is still intact. :up:

Ever so respectfully submitted with best regards (in spite of the risks involved) :roll: ,

"Skyhawk" :sunny:

[Munchausen]

:hmm: The O'Kane method still requires you to set the target's AOB +/- lead angle. From the looks of the TDC in your screenshots, it doesn't seem like you did it. Please clarify, 'cause I'm confused.

[Mush Martin]

:|\\ Who Knew ;)

[SteamWake]

While programming all this logic keep one thing in mind.

Its a pristine ocean. No currents, no 'real' kelp, and so on.. :)

[Diopos]

While programming all this logic keep one thing in mind.

Its a pristine ocean. No currents, no 'real' kelp, and so on.. :)

General sim comment not specific to SH4.

The fact that say an important environmental parameter such as currents is not explicitely and "continuesly" simulated in the game, does not mean that it is not taken into account in specific game aspects or events. If you had collected the perfect data set on a target which is "steady on its course" it wouldn't be important if it is close or further away. You're only concern would be if the impact point would be within your selected torp's range. But long shots were... longshots! :D They missed. Still assuming perfect target data, there are other parameters that influence a longshot (and currents seems to be an important one). In many sims paremeters not explicitely simulated maybe implicitely simulated, through the use of tables or random numbers that influence the specific game situation.
So if even if we don't "feel" the currents, that doesn't mean that there are not ingame situations that somehow take them into account.

Again I say that my comments are not specific for SH4.
(I don't know how the darn thing works!:D )

[Hitman]

Hello

I think that's the old convergence problem :p See this thread I opened long ago:

http://www.subsim.com/radioroom/showthread.php?t=121744&

Since your optics are not right above your torpedo tubes, there is a convergence correctiion needed, and there's where range matters.

[Rockin Robbins]

Actually, Hitman, your posts were what set me off to experiment to determine just how much difference it made. The answer: not much but plenty to cause muchas misses if you aren't careful.

I was using the stock game so I could see on the nav map exactly where I hit the target and determine where the boundaries were for accuracy in range. Although the aiming parameters would be the same in RFB and TMO, the premature shutdowns may be different in those two mods. That's why I asked for info in my first post. I'll do the research myself if nobody steps up.

@Munchausen: Actually I WAS set up for a Dick O'Kane, because the speed of those puppies really was zero. My Shooting Gallery Test Mission has them anchored out there so the only error can come from the inherent geometry of the torpedo course itself. My own submarine was also stationary.

The parallax between the position of the torpedo tubes and the position of the periscope or TBT has nothing to do with the problems. That difference is automatically compensated for by the TDC. In fact, the distance between periscope and torpedo tubes, both fore and aft, were adjustable! Now why would that be? Well, fleet boat lengths varied from the 253' length of the Gar class to the 311' length of the Gato and Balao classes. The adjustable parallax parameter made the TDC equally deadly in each.

And in the virtual ocean there are no currents. The wave action does not make surface currents that offset the aim of the torpedo at all. Our sim would have to be much bigger to account for those parameters. But if you think about it, since your submarine, torpedo and the target are both immersed in the same current conditions, the effect cancels out and it is just as if there were no current at all. Wave action, being very localized, would be different.

Now, to make sure I understand correctly:

You mean to say that the O'Kane method of torpedo firing solutions is less than accurate at long ranges?
Yup. But you can fix that by entering a range in the 2500-3000 yard area if you are firing a long shot.

That torpedoes both real and simulated sometimes fail to perform to specs?No, the specs call for a certain percentage of failures. That way, just like Microsloth, the anomalies become features, and actually raise the price of the product!


And speaking of "reach", while we are mixing simulated reality with reality itself . . .
Well, that's what I'm left with after the research. The devs did incredible research into the implications of TDC operation and actual torpedo placement that just about perfectly "mixed reality and simulation" here. This implies weeks or months work modeling an aspect of the game that nobody would ever appreciate (until crazy me came along with my shooting gallery). You know, the Mark 18 had a shorter reach and a tighter turning radius. I'll bet my shooting gallery would show the difference of the lesser parallax! The devs we often criticise are geniuses!

I fully expected that none of this complex and hidden geometrical quagmire would be there at all!

The biggest surprise for me: Awhile ago, someone asked why they could not set their TDC to range zero. He was all upset about it. So in my tests I tried some 8000 yard shots at the zero bearing with the TDC set to zero range. All the shots missed right. Any other range hit the target if the tropedoes got there. Anybody have any idea why that should be so? I think that is the only situation where the simulation yields different results than the real TDC.

[Hitman]

The parallax between the position of the torpedo tubes and the position of the periscope or TBT has nothing to do with the problems. That difference is automatically compensated for by the TDC. In fact, the distance between periscope and torpedo tubes, both fore and aft, were adjustable! Now why would that be? Well, fleet boat lengths varied from the 253' length of the Gar class to the 311' length of the Gato and Balao classes. The adjustable parallax parameter made the TDC equally deadly in each.


But the TDC can't automatically compensate everything. True it will take into account one side of the triangle, which is known -distance from the optics to the torpedo tube- but it still will lack the variable of distance to target in order to set the proper correction for parallax.

[Munchausen]

Actually I WAS set up for a Dick O'Kane, because the speed of those puppies really was zero. My Shooting Gallery Test Mission has them anchored out there so the only error can come from the inherent geometry of the torpedo course itself. My own submarine was also stationary.

Ah ha ... okay, I guess that accounts for the odd display on your TDC. I tested the "long shot" using your Cromwell zero-gyro setup instead ... adjusting my range so that I was 5,000 yards from the tanker when I fired. My results were as follows:

Calculated lead angle was 21 degrees. Neither the scope nor the TBT is calibrated to one degree ... and, as distance increases, errors in just half a degree can make a bigger difference in hitting or missing your target.
I left TDC range set to the 500 yard default. Didn't seem to make much difference.
Set my torpedoes to run slow at a depth of 17 feet ... keel depth minus 11 feet. Perhaps if you leave them set to default, they broach, then sink. Or, if you set them to the full keel depth, they go too deep, then sink. All four of mine made it to the target.

The O'Kane method can be combined with the Cromwell method ... the above test was made at very close to a 90-degree setup. The O'Kane method gives you the optimum AOA (broadside) and the Cromwell method gives you an exact lead angle.

:o But, the greater the range to target, the greater the need for exact accuracy in sighting your aiming device (TBT or scope).

The biggest surprise for me: Awhile ago, someone asked why they could not set their TDC to range zero. He was all upset about it. So in my tests I tried some 8000 yard shots at the zero bearing with the TDC set to zero range. All the shots missed right. Any other range hit the target if the tropedoes got there. Anybody have any idea why that should be so?

I'm surprised the torpedoes even headed in the correct direction. Try an attack in the "auto" mode and watch what happens to the TDC when a locked target gets really close to your sub. The "torpedo track" arrows go nuts ... almost like the old computer error of dividing by zero. If, in manual mode, the TDC thinks the target is at zero range, that might be enough for it to do what it does in auto mode.

[kylania]

The conclusions we can make here are the following. Don't shoot Dick O'Kane shots from more than 2000 yards, with torpedo gyro angles much above 15º left or right. Between 345 and 15, you'll get your hits. Outside that you better put a rough range estimate into the TDC. There's plenty of slop, but the more accurate the better.

Wasn't that always the Dick O'Kane method? 345-15 shot, 90 angle but range "doesn't matter" since it's only to be used against close targets (ie, 1500y or less, preferably much less)? I'm confused how range mattering is such a surprise now?

[Rockin Robbins]

The parallax between the position of the torpedo tubes and the position of the periscope or TBT has nothing to do with the problems. That difference is automatically compensated for by the TDC. In fact, the distance between periscope and torpedo tubes, both fore and aft, were adjustable! Now why would that be? Well, fleet boat lengths varied from the 253' length of the Gar class to the 311' length of the Gato and Balao classes. The adjustable parallax parameter made the TDC equally deadly in each.

But the TDC can't automatically compensate everything. True it will take into account one side of the triangle, which is known -distance from the optics to the torpedo tube- but it still will lack the variable of distance to target in order to set the proper correction for parallax.

But the parallax between the position of the torpedo tube and the periscope isn't the whole picture. The real parallax is between the periscope and the end of the reach, plus at least part of the radius of the turn. The part caused by the reach of the torpedo is much greater than the separation between tube and periscope. Now we've lost everybody!:rotfl:

I guess what I'm trying to say is that if the torpedo took a straight line out of the tube to the target, it would be hitting targets at 3000 yards without range input. Since it runs straight out the front for the length of the reach (don't have the figure in front of me, but it's more than the length of the submarine) and then turns, the parallax is great enough to cause misses.

I'm still amazed that the devs worked all this out and built it into the simulator. Not many have noticed it or poked at it with a stick like I have. Seems like a lot of work to entertain Hitman and Rockin Robbins.:rotfl:

[Skyhawk]

Seems like a lot of work to entertain Hitman and Rockin Robbins.:rotfl:

Stranger than YOU can imagine? :rotfl:

AFWIW, I find your posts highly entertaining, informative, and to be self-revealing. We truly are not worthy. :up:

Carry on . . . ;)

[Arclight]

I'm still amazed that the devs worked all this out and built it into the simulator.To be honest, I wouldn't expect anything less. You input the data to "fix" a point in space and the TDC works out how to get a torpedo to this intercept point. If the devs left that out, it would pretty much be impossible to get a torpedo on target, and they might as well have scrapped the game altogether...

[Mush Martin]

The biggest surprise for me: Awhile ago, someone asked why they could not set their TDC to range zero. He was all upset about it. So in my tests I tried some 8000 yard shots at the zero bearing with the TDC set to zero range. All the shots missed right. Any other range hit the target if the tropedoes got there. Anybody have any idea why that should be so? I think that is the only situation where the simulation yields different results than the real TDC.


Limitation of the medium I suspect.
the torpedo tells itself to arm in a
No arming zone and once it travels
beyond the set range it doesnt signal
arming.
(idiot speculation I have no data)

M

[elanaiba]

Torpedoes have a fixed arming range, depending on model. Its not related to the range you set in the TDC.

And of course, the range in the TDC is important to correct for paralax errors.

[Hitman]

But the parallax between the position of the torpedo tube and the periscope isn't the whole picture. The real parallax is between the periscope and the end of the reach, plus at least part of the radius of the turn. The part caused by the reach of the torpedo is much greater than the separation between tube and periscope. Now we've lost everybody!:rotfl:

Of course :yep: I took for granted that we were talking about the whole process until the torpedo takes the final, straight-running trajectory

I'm still amazed that the devs worked all this out and built it into the simulator. Not many have noticed it or poked at it with a stick like I have. Seems like a lot of work to entertain Hitman and Rockin Robbins.

Yeah, thus the money we paid for the game has been twice as good: we got the game and also a free puzzle to heat our brains :rotfl:

[elanaiba]

[quote]I'm still amazed that the devs worked all this out and built it into the simulator.

It wouldn't be a true simulator without it, would it?

We have some great programmers that like to research and do things properly, even before design asks something from them. One such example is Cristi Mihalache (one of the guys at the SH3/Microsoft booth at E3 a couple of years ago) who did the tdc code for SH3 and the impact angle calculations for torpedo duds purposes.

[Diopos]

[quote]I'm still amazed that the devs worked all this out and built it into the simulator.

It wouldn't be a true simulator without it, would it?

We have some great programmers that like to research and do things properly, even before design asks something from them. One such example is Cristi Mihalache (one of the guys at the SH3/Microsoft booth at E3 a couple of years ago) who did the tdc code for SH3 and the impact angle calculations for torpedo duds purposes.

You almost restored my faith to professional game designers.
Almost...
For a whole minute or so...
:rotfl:

:up: to Cristi Mihalache

Thanks for the game guys!:yep:

[Rockin Robbins]

[quote]I'm still amazed that the devs worked all this out and built it into the simulator.
It wouldn't be a true simulator without it, would it?

We have some great programmers that like to research and do things properly, even before design asks something from them. One such example is Cristi Mihalache (one of the guys at the SH3/Microsoft booth at E3 a couple of years ago) who did the tdc code for SH3 and the impact angle calculations for torpedo duds purposes.

Actually that was my quote. I just thought it was time you devs got some demonstrated credit for all the hidden work you do. Time after time people have called bug on something that was really a carefully researched proper simulation of a little known corner of reality.

I particularly remember the screaming about the sonar working on the surface "bug" and then showing that the sonar could continue to "work efficiently on the surface" according to the Submarine Sonar Operator's Manual.

Frequency of air attacks is another area where you devs take unjustified abuse. If you play with the airplanes they'll certainly play with you.:arrgh!:

Anyway, poking the simulator with a stick revealed the underlying complexity and allowed us to appreciate the work devs do. Too often (insert disparaging adjective) people have suggested that Ubi should just hire modders to put the next sub simulator together. There is a HUGE difference between modding and developing.:up:

[gutted]

i see you've finally figured out what i had been talking years ago :D

range doesn't matter as long as the gyro is 0. the further away from 0 the more it matters due to the torpedo's initial run before turning.

thats why it's best to shoot when the gyro is close to 0, to cancel out any descrpencies in your calculated range. had the torpedos been mounted on a turret, the would be NO gyro angle.. and the range wouldn't matter.

you can put a fancy name on it and call it a cool method.. but it's just common sense.

[Rockin Robbins]

i see you've finally figured out what i had been talking years ago :D

range doesn't matter as long as the gyro is 0. the further away from 0 the more it matters due to the torpedo's initial run before turning.

thats why it's best to shoot when the gyro is close to 0, to cancel out any descrpencies in your calculated range. had the torpedos been mounted on a turret, the would be NO gyro angle.. and the range wouldn't matter.

you can put a fancy name on it and call it a cool method.. but it's just common sense.Well gutted, I actually understood that. I was poking the simulator with a stick to answer the question "How MUCH does range matter, what is the allowable error and how does all that play when shooting ridiculous ranges? What about Mary Lou?" It was sort of like investigating the effect of gasoline on fire.:88) But not quite as much fun.

I had figured the error out back in the necro thread. You dredged up the thread where arronblood, you and I first got together to see if these fleet boats could do what U-Boats could. Remember, I dragged out WernerSobe's Natural Sinking Mechanics Test Mission and plugged ships from different angles there, concluding that Dick O'Kane from similar 1000 - 1500 yard distances would work with a gyro angle up to 30º? You educated me on the theory, aaronblood provided MoBo and more theory and I adopted it to fleet boats and did my PT Barnum thing without all the pretty girls and elephants. Part and parcel of Dick O'Kane was to get pretty close to zero gyro angle (although I kept it simple and never talked about that. I just said that the nearer the target was to a 90º angle when hit, the more error the method could absorb).

John P Cromwell also works from a near or exactly zero gyro, but the heart of the method is the simple rule of thumb for calculating the AoB (45-bearing from the bow). Actually we could have made a more complicated rule that would allow people to take any angle they chose. But my crime signature has always been to assemble fixed attack methods, governed by simple rules of thumb, with no external calculators or charts. I eliminate every single step that doesn't cause a miss. My "everything I needed to know about submarines I learned in kindergarten" approach is done on purpose because my goal is to get the game newbie to check that manual targeting box and KNOW they can go out there and sink ships with confidence.

Your observation was also at the root of the same conversation between me and Nisgeis, the man who suggested the 45º angle attack. He saw the heart of the technique as vector analysis to get that perfect zero gyro shot. I saw the heart of the method as the simple formula to calculate AoB that made any external calculation or remembering torpedo speeds unnecessary. I admit that I am always ready to toss out any step that isn't absolutely necessary. I admit I am willing to sacrifice precision for "close enough" if it means the procedure is easier. My focus is on the beginner and there is no limit to the foolishness I will engage in to convince them to shoot manually. I have no shame. Mr. Rogers' rotting corpse paid me a visit last night to kill me for my equally smelly imitation.:rotfl:

I know that's frustrating to you advanced shooters. I drive aaronblood crazy with my oversimplifications. But Dick O'Kane and John P Cromwell aren't for advanced shooters, even though they will still work for them. They might be a good starting point, but all kinds of refinements and variations are possible. I understand that, but pardon me if I keep it SIMPLE. You guys are already deadly. I'm just trying to enlarge the club.

[Hitman]

range doesn't matter as long as the gyro is 0. the further away from 0 the more it matters due to the torpedo's initial run before turning.

Actually YES it matters even at zero G-Angle :)

There will still be a difference -although minimal- in parallax due to the distance from the torpedo initial position (In its tube) to the optics. And, if you are not using an automated calculator (Like the TDC) but instead shooting based on a manually calculated lead-angle (A la WW1) you would also need to take into account the time that the torpedo takes to accelerate to its cruise speed, because you will have had the firing triangel set up with that speed, and the overall average of the run will in fact be slightly slower. ;)

[Rockin Robbins]

range doesn't matter as long as the gyro is 0. the further away from 0 the more it matters due to the torpedo's initial run before turning.
Actually YES it matters even at zero G-Angle :)

There will still be a difference -although minimal- in parallax due to the distance from the torpedo initial position (In its tube) to the optics. And, if you are not using an automated calculator (Like the TDC) but instead shooting based on a manually calculated lead-angle (A la WW1) you would also need to take into account the time that the torpedo takes to accelerate to its cruise speed, because you will have had the firing triangel set up with that speed, and the overall average of the run will in fact be slightly slower. ;)
And since the distance to accelerate to full speed remains constant regardless of target distance, the average speed will vary with target distance. http://i196.photobucket.com/albums/aa293/RockinRobbins13/smileys/shouting.gif

Fortunately this means that the effect is greater on short range shots where you have greater error tolerance than it is on long range shots. This ONE TIME geometry finally decides to work for us instead of against us.:up:

[CaptainHaplo]

Well - I gotta say this - I don't use perfect solutions - I dont use any "system" for shooting - I basically do it this way and it works great for me.

#1 Get in front of my target
#2 As it approaches - get close
#3 When its filling my scope - range somewhere around 1200 yds - start turning to bring the tube I want to fire to bear.
#4 Use speed and rudder as needed - but when the target is bloody close and around 12-15 degrees off my centerline and approaching the 0 or 180 mark - go to 0 or 180 degrees scope view (fore or aft shot defines this) and fire. Due to speed and close range - the target and fish meet, with a rather explosive reaction.

Note there are times when due to the approach angle you can tell that your too close - just hit the gas and it get your torp arming room. Also, there are times when an unlucky zigzag will keep this from working - such is life. But if your close, and not spotted on the attack, a zig can actually give you a shot from your other set of tubes.

The key is get close - then get closer.

[gutted]

"The key is get close - then get closer."

so true.. in many forms of warfare.

it's the same motto i live by when i fly ww2 sims. as can be seen in my movies:

http://www.youtube.com/user/JG52Gutted

highly recommend "legend". lots of fireworks hehe. killing spree is my second favorite.

[Steeltrap]

Currents are only a factor when not uniform. If there is a 2kt SE current then everything in the area will be affected by that current. There is, therefore, no relative difference, and only a relative difference will have an effect.

Worth noting, too, that the official spec for USA torps was to hold within 0.5 degrees of specified course. O'Kane made the point in Clear the Bridge that they were generating solutions with accuracy greater than their weapon was able to achieve i.e once your solution is within the accuracy of the ability of the weapon to achieve, a more accurate solution makes no difference at all.

[Rockin Robbins]

Absolutely true on the accuracy. Your accuracy can also be no better than your ability to measure, so you have two sources of error which can either add together to make a greater error, or partially cancel each other out.

Yes, getting close makes your solution more tolerant. I have shot three shots over 2000 yards in my career, ever. For my shooting gallery testing I chose to go with 8000 and 3000 yard ranges to magnify parallax errors in order to quantify them more accurately.

Based on those tests, I would NEVER shoot over 3000 yards unless an aircraft carrier was there. Then I would shoot all six forward torpedoes, knowing that perhaps three of them would reach the set range. Maybe I would obtain enough damage from the three survivors to stop my victim so I courld finish him off. Needless to say, I'd never shoot a measly four stern torpedo tubes more than 3000 yards, even for an aircraft carrier.

My favorite range is about 700 yards, less if possible.

[Wilcke]

Good stuff! RR time for the John P Cromwell Video Tutorial my man! No rest!

[kiwi_2005]

Good stuff! RR time for the John P Cromwell Video Tutorial my man! No rest!

Yes a video tutorial would be great:yep:.

With SH3 manual targetting it all comes together for me i can sink a moving target at 2400yrds easily although i hardly do as i wait for them to get much closer but sometimes i got no choice when a destroyer is bearig down. I learnt from the game manual yes its basic but thats all you need ive never had crazy shots. Its really 4 easy steps: Identify, Range, Angle on the bow and then Speed. Then once thats sorted out fire away. I get more hits than misses.

But with SH4 manual targetting I completly SUCK at it:damn:. Its like back to the drawing board, where i just give up and change to auto targetting. I tried a few tutorials in the early days of SH4 but my shots are always way way far off from the target. :nope:

[Rockin Robbins]

Kiwi, you are missing astern because you are developing information and entering it into the TDC in the wrong order.

With the U-Boat, the TDC does not follow the enemy because it doesn't have a position keeper. It doesn't matter what order you enter the info into the German TDC, because your periscope position tells the TDC where the enemy is. Actually, it would be best to enter range last then point and shoot for greatest accuracy, because the German TDC is not updating that range with time.

In the American TDC with the PK on, the TDC is moving the impact point of your torpedo, shown with an x on the attack screen, so that it moves WITH the target. Once you get that x moving at the same course, speed and position of the target, and unless the target changes course or speed you don't even have to look at him again. You can fire any time at all and your torpedo hits him.

But in order to hit him, you have to enter your data in a certain order. First, enter those parameters that do not change: speed and course (AoB). AoB does change, but isn't so critical, so enter it second and turn on the pk either first or after you enter speed. Your last information is the position of the enemy and it's critical that the PK be on before you do this. Then take a stadimeter measurement and send the range/bearing last. This fixes the position of your impact point right on top of the target. And with the course and speed already waiting in the TDC the PK immediately starts moving that impact point in the correct direction at the right speed.

Good idea to check out your attack map to see the x and target. Is the x moving slightly slower than the target? Notch up the speed a knot and see how it does. Is it drifting left or right relative to the target? That's a course error. Correct that in the TDC to make it move on the correct course. Now take a final position sight to get the x back on top of your target.

It has to stay there for a certain length of time for success. How long? The attack screen tells you at the end of the plotted torpedo course. If it says three minutes, your x has to stay on top of the target for three minutes. If it is in front of or behind the target and a line between your sub and the x intersects the target, that is a hit too. Happy? You'll shoot and hit this time.

I have a John P Cromwell video (http://files.filefront.com/John+P+Cromwell+Tutorial7z/;12127008;/fileinfo.html). It also contains the first published successful daylight surface attack. I did it with the stock game. Toward the end I lost synch between sound and video. It gets about five seconds off, but because of the first successful daylight surface attack, I left it until I can replicate the results. I said I only got two hits but on viewing the results heard four clear hits at the end of the video.

This video is shot, as usual, in the safe balmy waters off the coast of California near Catalina Island. After announcing that, our captain goes up on deck to discover he's in a raging thunderstorm. He is not pleased....

[kiwi_2005]

Kiwi, you are missing astern because you are developing information and entering it into the TDC in the wrong order.

With the U-Boat, the TDC does not follow the enemy because it doesn't have a position keeper. It doesn't matter what order you enter the info into the German TDC, because your periscope position tells the TDC where the enemy is. Actually, it would be best to enter range last then point and shoot for greatest accuracy, because the German TDC is not updating that range with time.

In the American TDC with the PK on, the TDC is moving the impact point of your torpedo, shown with an x on the attack screen, so that it moves WITH the target. Once you get that x moving at the same course, speed and position of the target, and unless the target changes course or speed you don't even have to look at him again. You can fire any time at all and your torpedo hits him.

But in order to hit him, you have to enter your data in a certain order. First, enter those parameters that do not change: speed and course (AoB). AoB does change, but isn't so critical, so enter it second and turn on the pk either first or after you enter speed. Your last information is the position of the enemy and it's critical that the PK be on before you do this. Then take a stadimeter measurement and send the range/bearing last. This fixes the position of your impact point right on top of the target. And with the course and speed already waiting in the TDC the PK immediately starts moving that impact point in the correct direction at the right speed.

Good idea to check out your attack map to see the x and target. Is the x moving slightly slower than the target? Notch up the speed a knot and see how it does. Is it drifting left or right relative to the target? That's a course error. Correct that in the TDC to make it move on the correct course. Now take a final position sight to get the x back on top of your target.

It has to stay there for a certain length of time for success. How long? The attack screen tells you at the end of the plotted torpedo course. If it says three minutes, your x has to stay on top of the target for three minutes. If it is in front of or behind the target and a line between your sub and the x intersects the target, that is a hit too. Happy? You'll shoot and hit this time.

I have a John P Cromwell video (http://files.filefront.com/John+P+Cromwell+Tutorial7z/;12127008;/fileinfo.html). It also contains the first published successful daylight surface attack. I did it with the stock game. Toward the end I lost synch between sound and video. It gets about five seconds off, but because of the first successful daylight surface attack, I left it until I can replicate the results. I said I only got two hits but on viewing the results heard four clear hits at the end of the video.

This video is shot, as usual, in the safe balmy waters off the coast of California near Catalina Island. After announcing that, our captain goes up on deck to discover he's in a raging thunderstorm. He is not pleased....
Yea with the uboat i always find its a good habit to enter range again just before i fire as sometimes i will do all the data way before im ready to fire the shot, so ive done the data then creep up on my target, when around 1200yrds will do the data again (dont know if i need to but i do it anyways) or just redo the range.

Your explaining of the American boats helps alot, i think i know what your meaning now. Will give it a go next time im in the game. Will check out the video :up: