Did WWII subs perform TMA plots - if not why?
 

I have read two books by O'Kane "Wahoo" and "Clear the Bridge!". It seems WWII subs often had potential targets under observation for anywhere from 30 minutes to many hours. Yet, as best I can tell, TMA (speed, range, and course) was solved by the following methods:

(1) Stadimetric visual observations for range and angle on the bow (course derivative).

(2) Occassionally radar was used for ranging.

(3) Ocassionally active sonar was used for ranging.

(4) Passive sonar for counting screw turns to estimate speed.

From my experience with Sub Command, it is clear that TMA via plotting can be done with any form of LOB (line of bearing like visual sightings) data and a plotting board without any electronic technology.

So, my question is why wasn't TMA plotting techniques not used or was it and I simply missed it in my readings?

Thanks.

PS: Cross-posted on the DW and SHIII forums, since I am not sure that the two communities are one in the same.

Well, I know not much about old subs, but didn't these suffice well? In fact, was there any other way to do it that would be more efficient?
I'm not really sure what you're asking... "Why weren't they not used" is a tricky way to phrase oneself.
These ARE plotting techniques. :D

Yes, there is an extra negative in there.

It just occurred to me that the whole first leg issue of LOS type is a non-issue if you have visual on the hull of the ship.

Well, going from Sub Command to Silent Hunter III, I found myself doing the following...

1) Get contact on hydrophone, let's say bearing 010. I then mark a line from ownship out 25km or so on that bearing.

2) I listen for a few minutes while stationary to get it's rough direction.

3) I start moving in what I think is the right direction.

4) Exactly ten, or perhaps thirty minutes after first contact, I draw another bearing line. The interval is not important as long as it's maintained.

5) I repeat another couple of times, then comes the tricky part.

6) I try to draw a line through all the bearing lines where the distance travelled between each one is constant, sound familiar?

7) Having, hopefully, plotted the enemies course, I simply sprint ahead to a good firing position and wait.

This method has proven quite accurate when combined with instinct, and also, it really improved my TMA skills in Sub Command. :D

But my point is that I'm sure some kind of manual TMA was used for long-range tracking in WW2, it's just too simple... But for things like fire-control, it was apparently possible to do it, but much simpler and accurate to go to the ole periscope.

I think that on WW2 subs, the primary sensor in good conditions was the periscope. And at night the UZO on the bridge. So bearing and course we obtained visually.

Yes they performed plots. Radar plots were extensively used once that became available, and I think even with visual sightings plots were used (though not always). As for plotting with sound, I think it was done but not very often. I posted a link to a WWII era fire control manual in the SH2PA forum, should give you an idea of the type of stuff they plotted.

Re: Did WWII subs perform TMA plots - if not why?
 

They had a mechanical computer that could compute the target’s course & speed as well as compute the torpedo’s turn angle given observational inputs.

Advanced TMA techniques like the Ekelund range appeared after the war.