Something interesting about the TDC:
"The heart of the torpedo fire control system was the torpedo calculator designated T. Vh. Re. S3, manufactured by the
Siemens Company . . .
The development of this calculator started around the year 1939. In 1941 it was (together with the whole torpedo fire control system) delivered to the
Kriegsmarine for testing. In the same year – after successfully passing all tests – the newly manufactured calculators were fitted in the front-going U-Boats.
From 1941 when the calculator entered service, till the end of the war, there were some modifications to its construction." (
http://www.tvre.org/en/torpedo-calculator-t-vh-re-s3)
The TDC which appears in-game is this TDC. But this TDC didn't enter service, according to the aforementioned article, until 1941, two years
after the war started.