Ok, here a resume because I always play with Auto TDC:
Sorry to contradict Vecko the TWoS maker, but NO, it's not as he says that you just point and fire. That's enough to test a mod, but not enough to play the game...
The procedure is this (TWoS 2.2.6 and before):
a) If you want to identify the ship before you fire...(realistic, isn't it?)
First you must untick 'Manual TDC' in the game options (in the bunker for campaign; in main menu for single missions);
You have to switch to 'false' the value in the OFEV mentioned in the early post above;
You have to install an additional TWoS mod for the radio man and auto ID;
On periscope, you have to click on WO picture and turn off Auto TDC;
Then you have to click the Weapon officer (3rd icon from left), then 2 times the first icon in the dialogue from left; this will identify ship in manual TDC;
Then you change back to Auto TDC... next go to b).
b) If you want to fire immediately without ID the ship...
You lock target with space; you unlock target; you make the final aim with the mouse moving the periscope aiming mark for the final trajectory; you fire torpedo (before you flood the torpedo and set depth and detonation method).
As you can see it's far away and more complex than in SH3, and all but intuitive... and IMO it's worth a mention in the TWoS instructions, also considered that it's the 2nd time today that I have to write this HowTo so I guess people are interested :=)
Good hunting,
