Yet another TDC question - what do these show?

panthercules · 04-13-07, 01:14 AM

Ok - I obviously do not have the hang of this US TDC. I've watched the Neal video (very cool) and read several TDC-related threads, but I still don't really understand exactly how this thing is supposed to work (even when it's not having it's bug with targets on the "wrong" side).

I understand how to enter all the relevant data and send it to the TDC - what I don't get is how you're supposed to be able to read off of the PK to see if your solution is holding up well over time. Using the screenshot below, can someone who really knows enlighten me as to exactly what these two arrow/indicators highlighted on the left side of the screen are supposed to be showing?

I thought that you were supposed to be able to look at the PK and read what it thought the range, bearing and AOB were, and then you could compare those PK values against your observed values after some elapsed time and thereby tell whether the solution was good or not. If that were the case, then I would have expected that arrow/indicator No.1 in the image above would be showing the PK's calculated AOB, but it clearly isn't. I also would have thought that the arrow/indicator No. 2 would be showing the PK's calculated bearing of the target from your boat, but it clearly isnt. (Both are off by some 20-30 degrees or more from the "actual" values seen in the scope, even though this shot was taken immediately after the values were sent to the TDC by clicking the red button on the dial in the top right of the screen (cropped out of this image).

It looks like arrow 1 is actually showing torpedo impact angle on the target and arrow 2 is showing gyro angle for the torpedo - both interesting tidbits but completely useless for trying to compare your observed data against the PK data to check your solution's validity.

So, what am I missing here (besides the targets)??

fullmetaledges · 04-13-07, 01:47 AM

Quote:

Originally Posted by panthercules

It looks like arrow 1 is actually showing torpedo impact angle on the target and arrow 2 is showing gyro angle for the torpedo - both interesting tidbits but completely useless for trying to compare your observed data against the PK data to check your solution's validity.

You answered your own question about the arrows. I'm sure your activating the pk right? If so a white x will show up on your attack map(make sure you have the right torp tubes selected), that is the position keeper. If you have map contacts on then you can see if your position keeper is staying in the center of your target or whether you need to correct it's position. If not then you need to make sure that the PK is where you observed your target to be.

heartc · 04-13-07, 01:59 AM

Short answer, since I'm low on time:

Did you *activate* your PK? Asking cause I can't see it in the picture, the red button on the lower left is not visible.

The first dial should indeed show AOB, I think. But this is unimportant*. What is important for solution checking is the lower dial. The indicator here shows the gyro angle, and the relative target bearing is *at the 12 oc position* of this dial. Looks pretty good to me in your pic until this point. Computed relative and sighted relative bearing are both 56.
Also, in your example the bug is not at work; otherwise, it would show "0" at the 12 oc position (although the TDC would still be working true - it's just a wrong readout).

*When the relative and sighted relative bearings stay the same, the torpedos will run at the proper intercept course no matter what. You could have a wrong AOB, for example too small, but when you also have a wrong speed, in this case too high, those both errors may well cancel each other out and the bearings stay true. This is why you could simply doctor on your solution by changing the speed data until bearings fit, if the dial would not be bugged as often as it is. Would be cool if they fixed that.

heartc · 04-13-07, 02:01 AM

My answer is for people playing w/o map contact updates.

fullmetaledges · 04-13-07, 02:02 AM

your more of a purist than I

panthercules · 04-13-07, 08:45 AM

Quote:

Originally Posted by heartc

My answer is for people playing w/o map contact updates.

Thanks - I don't play with map updates on and I don't really use the attack map anyway since you don't seem to be able to mark on it (at least that was true in SH3 - can you mark on it in SH4?).

Yes - I do have the PK activated - I just cropped the picture to blow it up and the red light got cut off. so I guess you just have to guesstimate the 12 o'clock position on the lower dial and check it against your observed bearing to target? Too bad it isn't a bit more easily readable, but at least now I know what to look for.

My biggest problem appears to be speed, especially with the higher speed warships and tankers - spreads help a little but I've still been missing like crazy with any target going more than about 10 knots, even when I had what seemed to be solid speed estimates using the 3-minute method. Also, this TDC seems to require an entirely new method of approach. With the German TDC, most times I could set up my firing solution in advance, entering all the info into the TDC based on what the data would be when I reached my pre-chosen firing position - then, I just fired as soon as my target reached my chosen position. Normally, once I had my solution set up, all I had to do was wait till my target reached (say) 345 degree bearing and then fire, which let me keep my periscope usage to an absolute minimum during the last part of the attack run.

I assume that once you get used to it this new TDC/PK will become just as easy to use - just hope they manage to fix the problems with it by the time I get out of sub school

Nightmare · 04-13-07, 11:10 AM

You've got the arrows right as far as the top one is impact angle and the lower one is torpedo gyro angle. The one that you are looking for to check the solution is the inner ring on the own ship dial (the bottom one). If you pop the scope up and the inner dial reads 40 and the target is roughly on 40 degrees on the scope, you know you’ve got a fairly accurate solution.

The great thing about the US TDC over the German one was that it continually updated the torpedo gyro angles. This means that the time it takes for the outer doors to open and for the tube to fire won’t throw off your solution. You also don’t even need the scope raised or pointed at the target to fire either as long as the PK is activated.

If your initial speed, range, and AOB are accurate and the target doesn’t change course or speed, you only have to pop the scope up to confirm the bearing with the PK.

panthercules · 04-13-07, 08:04 PM

Is there a key command/toggle that will automatically pull all the TDC consoles out and put them away all at once, or do you have to keep clicking the tab on each one to display them one at a time? I hope there is, or that someone could mod it to make that happen - I like having these things accessible from the periscope/TBT screens, but the tab-clicking thing is pretty cumbersome. I hope they can be resized/moved a little so they don't overlap the field of view, and the recognition manual resized/shrunk some as well - the current set up feels very cluttered for some reason.

I'm still surprised there wasn't some sort of marker/indicator at the 12 o'clock point on that lower dial, to make it easier to read the bearing to target - maybe the dial was so big IRL that this wasn't a problem, but it is kinda tough on my monitor screen.

04-13-07, 01:14 AM	#1
panthercules The Old Man Join Date: Apr 2005 Posts: 1,336 Downloads: 6 Uploads: 0	Yet another TDC question - what do these show? Ok - I obviously do not have the hang of this US TDC. I've watched the Neal video (very cool) and read several TDC-related threads, but I still don't really understand exactly how this thing is supposed to work (even when it's not having it's bug with targets on the "wrong" side). I understand how to enter all the relevant data and send it to the TDC - what I don't get is how you're supposed to be able to read off of the PK to see if your solution is holding up well over time. Using the screenshot below, can someone who really knows enlighten me as to exactly what these two arrow/indicators highlighted on the left side of the screen are supposed to be showing? I thought that you were supposed to be able to look at the PK and read what it thought the range, bearing and AOB were, and then you could compare those PK values against your observed values after some elapsed time and thereby tell whether the solution was good or not. If that were the case, then I would have expected that arrow/indicator No.1 in the image above would be showing the PK's calculated AOB, but it clearly isn't. I also would have thought that the arrow/indicator No. 2 would be showing the PK's calculated bearing of the target from your boat, but it clearly isnt. (Both are off by some 20-30 degrees or more from the "actual" values seen in the scope, even though this shot was taken immediately after the values were sent to the TDC by clicking the red button on the dial in the top right of the screen (cropped out of this image). It looks like arrow 1 is actually showing torpedo impact angle on the target and arrow 2 is showing gyro angle for the torpedo - both interesting tidbits but completely useless for trying to compare your observed data against the PK data to check your solution's validity. So, what am I missing here (besides the targets)?? __________________

04-13-07, 08:04 PM	#8
panthercules The Old Man Join Date: Apr 2005 Posts: 1,336 Downloads: 6 Uploads: 0	Is there a key command/toggle that will automatically pull all the TDC consoles out and put them away all at once, or do you have to keep clicking the tab on each one to display them one at a time? I hope there is, or that someone could mod it to make that happen - I like having these things accessible from the periscope/TBT screens, but the tab-clicking thing is pretty cumbersome. I hope they can be resized/moved a little so they don't overlap the field of view, and the recognition manual resized/shrunk some as well - the current set up feels very cluttered for some reason. I'm still surprised there wasn't some sort of marker/indicator at the 12 o'clock point on that lower dial, to make it easier to read the bearing to target - maybe the dial was so big IRL that this wasn't a problem, but it is kinda tough on my monitor screen. __________________

04-13-07, 01:59 AM	#3
heartc Samurai Navy Join Date: Dec 2006 Location: Munich Posts: 562 Downloads: 71 Uploads: 0	Short answer, since I'm low on time: Did you activate your PK? Asking cause I can't see it in the picture, the red button on the lower left is not visible. The first dial should indeed show AOB, I think. But this is unimportant. What is important for solution checking is the lower dial. The indicator here shows the gyro angle, and the relative target bearing is at the 12 oc position* of this dial. Looks pretty good to me in your pic until this point. Computed relative and sighted relative bearing are both 56. Also, in your example the bug is not at work; otherwise, it would show "0" at the 12 oc position (although the TDC would still be working true - it's just a wrong readout). *When the relative and sighted relative bearings stay the same, the torpedos will run at the proper intercept course no matter what. You could have a wrong AOB, for example too small, but when you also have a wrong speed, in this case too high, those both errors may well cancel each other out and the bearings stay true. This is why you could simply doctor on your solution by changing the speed data until bearings fit, if the dial would not be bugged as often as it is. Would be cool if they fixed that.

04-13-07, 02:01 AM	#4
heartc Samurai Navy Join Date: Dec 2006 Location: Munich Posts: 562 Downloads: 71 Uploads: 0	My answer is for people playing w/o map contact updates.

04-13-07, 02:02 AM	#5
fullmetaledges Chief Join Date: Jul 2006 Location: Utah Posts: 314 Downloads: 120 Uploads: 0	your more of a purist than I

04-13-07, 11:10 AM	#7
Nightmare Engineer Join Date: Nov 2003 Location: Portland, OR Posts: 210 Downloads: 10 Uploads: 0	You've got the arrows right as far as the top one is impact angle and the lower one is torpedo gyro angle. The one that you are looking for to check the solution is the inner ring on the own ship dial (the bottom one). If you pop the scope up and the inner dial reads 40 and the target is roughly on 40 degrees on the scope, you know you’ve got a fairly accurate solution. The great thing about the US TDC over the German one was that it continually updated the torpedo gyro angles. This means that the time it takes for the outer doors to open and for the tube to fire won’t throw off your solution. You also don’t even need the scope raised or pointed at the target to fire either as long as the PK is activated. If your initial speed, range, and AOB are accurate and the target doesn’t change course or speed, you only have to pop the scope up to confirm the bearing with the PK.