German TDC

[Bubblehead1980]

Coming from the Us side of things in SH 4...


I play without map contacts most of the time and have a high hit rate. A lot of it has to do with 3D TDC and a functioning linked radar range unit in TMO, this permits realistic targeting.


Anyways, I have little to no experience in in UBoats but have jumped in. Running Dark Waters mod for SH 4. I know this is SH 3 but from videos watched there are similarities to U boat side of things and these forums are the center of expertise on U Boat sims, so asking here.



German TDC is well different....What is the function of where you can "lock" in info and it seems linked to the periscope/Uzo, but turn off to enter fire control data.


Is this a form of Position Keeper? I thought US TDC was only one with the PK. Info does not seem to update though, so dont thin a PK.




What is best method of ascertaining speed?


With map contacts off on US side, I take range/bearing readings, mark the map and time for 3 minutes...900 yards=9 kts.


I am still adjusting to using metric system lol but should time for 3 minutes 15 seconds for metric correct?


Any advice etc is greatly appreciated. I want to do manual with map contacts until I adjust to U Boats, then move on to running without map contacts.

[Rhodes]

http://www.tvre.org/en/torpedo-fire-...german-u-boats


Great info about U-boat TDC.



In game, the is a button that we the turn of the auto-update (link form uzo/periscope) and can introduce the info. When turn back on, when turning the bearing, the AOB turn also, so updated.

Normally I use the 3m15s rule.

[Bubblehead1980]

Originally Posted by Rhodes

http://www.tvre.org/en/torpedo-fire-...german-u-boats


Great info about U-boat TDC.



In game, the is a button that we the turn of the auto-update (link form uzo/periscope) and can introduce the info. When turn back on, when turning the bearing, the AOB turn also, so updated.

Normally I use the 3m15s rule.

Excellent info! Thanks.


3 minutes 15s it is. So they travel 900 meters, speed is 9 kts or do require some conversion? (sorry, metric just throws me off and I was certainly no math major lmao)

[Rhodes]

Originally Posted by Bubblehead1980

Excellent info! Thanks.


3 minutes 15s it is. So they travel 900 meters, speed is 9 kts or do require some conversion? (sorry, metric just throws me off and I was certainly no math major lmao)

From my understanding, is similar. It's 9 kn. You can do 3.15 and multiply by 10 (according with a post a long saw) but the result would be 9000=9 knots.

Now I do not know if real life is done like this or just the game.

In sh3: 3m15s - gives me 900m, it's 9 kts.

Sh4: 3m - 900 yards its 9 kts. Yes? no? nim?



In sh3, we have a almost cheat/work around and use the weapons officer. I can use it to see what mistakes I did on my data. Normally my difficulty in both games is getting the speed of target right.

But, in sh3, on the surface I use the WO, since I think of him like my first watch officer (similar to the XO/first officer on US subs) and on U-boats, they were in charge of the surface attacks, gathering the info and reporting to person managing the TDC.

[derstosstrupp]

If you want to mimic historical procedures, the main methods of getting speed were:

1. Ausdampfen: this is matching course and speed at a distance, on the surface. Can be done in game even without map contacts by carefully watching the target and adjusting own course and speed until a) the bearing no longer changes and b) the target appears to stay at the same range. To be accurate, best to do it over 30 minutes. 10 can suffice. It is most accurate at AOBs near 90, or near zero. As a sidenote, this is as you know very similar to how the US TDC was used to refine target data - adjusting the computer til bearing and range matched. The Germans just did it with their boat. Disadvantage here being no ability to refine the data once done with Ausdampfen.

2. Koppeln: this is plotting based on exact bearings and estimated ranges. The real guys were able to accurately estimate range based on how much mast was showing over the horizon and could use a Peildiopter (a pelorus) to get accurate true bearings. Also can be done in game with adequate practice estimating ranges by eye.

3. Schätzung: plain old seaman’s eye estimation, but also could include the “fixed wire” method of estimating speed by timing how long it takes for the target to transit the vertical line. They estimated length for this purpose based on an estimate of tonnage. The real guys (same as the Americans) did not rely on or have good rec manual data.

Any questions on the German TDC I’m happy to answer. Tvre.org is great but has some small errors here and there (he didn’t have all the documentation we now do when he sadly passed).

To answer your question about the position keeper, the German TDC at least from 1940 and forward, in other words the model S3, had a functionality called Lage laufend. That took advantage of the fact that every degree of bearing change equals 1° of AOB change. The computer also had direct connection to the gyrocompass and so, when told to do so, the computer would take own course changes into account as well as bearing changes such that if you kept the optics on target, the AOB would be correct regardless of own maneuvers. So you could call it AOB tracking is what it had. And then to minimize errors caused by parallax, they would strive for a zero or near zero gyro angle shot and then roughly input the range. SH games do not implement the gyrocompass connection and so own course changes will not be taken into account.

This writeup I did explains the mixture we have:

https://www.subsim.com/radioroom/sho...&postcount=209

[Bubblehead1980]

Originally Posted by derstosstrupp

If you want to mimic historical procedures, the main methods of getting speed were:

1. Ausdampfen: this is matching course and speed at a distance, on the surface. Can be done in game even without map contacts by carefully watching the target and adjusting own course and speed until a) the bearing no longer changes and b) the target appears to stay at the same range. To be accurate, best to do it over 30 minutes. 10 can suffice. It is most accurate at AOBs near 90, or near zero. As a sidenote, this is as you know very similar to how the US TDC was used to refine target data - adjusting the computer til bearing and range matched. The Germans just did it with their boat. Disadvantage here being no ability to refine the data once done with Ausdampfen.

2. Koppeln: this is plotting based on exact bearings and estimated ranges. The real guys were able to accurately estimate range based on how much mast was showing over the horizon and could use a Peildiopter (a pelorus) to get accurate true bearings. Also can be done in game with adequate practice estimating ranges by eye.

3. Schätzung: plain old seaman’s eye estimation, but also could include the “fixed wire” method of estimating speed by timing how long it takes for the target to transit the vertical line. They estimated length for this purpose based on an estimate of tonnage. The real guys (same as the Americans) did not rely on or have good rec manual data.

Any questions on the German TDC I’m happy to answer. Tvre.org is great but has some small errors here and there (he didn’t have all the documentation we now do when he sadly passed).

To answer your question about the position keeper, the German TDC at least from mid 1941 and forward, in other words the model S3, had a functionality called Lage laufend. That took advantage of the fact that every degree of bearing change equals 1° of AOB change. The computer also had direct connection to the gyrocompass and so, when told to do so, the computer would take own course changes into account as well as bearing changes such that if you kept the optics on target, the AOB would be correct regardless of own maneuvers. So you could call it AOB tracking is what it had. And then to minimize errors caused by parallax, they would strive for a zero or near zero gyro angle shot and then roughly input the range. SH games do not implement the gyrocompass connection and so own course changes will not be taken into account.

This writeup I did explains the mixture we have:

https://www.subsim.com/radioroom/sho...&postcount=209

Thank you for the detailed answer.

I will post some questions soon.