Fantastic progress
Now I must add something about british torpedoes here: British WW2 submarines did their firing solutions in the old WW1 style
because the inter-war state money cuts depraved them of resources to develop a really good TDC. Thus, their computer -called "The fruit machine"- was only a tool for predicting target position -much like the position keeper in the US subs, and check that way if estimated target data were correct or not, but it didn't give as output anything else than the lead angle (Periscope bearing to the target at which you must shoot your torpedoes with 0º Gyro Angle to hit the enemy) and it didn't by any means update the torpedos GA, which was fixed at zero except when doing spreads -in which case the commander told the torpedo room to enter the gyro manually on some tubes.
To sum this all up: If you want hardcore realism, you must do a set of torpedoes -even if they are optional for the player- which do NOT turn, i.e. they will always go straigth from the bow or stern, so you need to swing the full boat to a perpendicular course to the enemy target and fire at the proper periscope bearing of the enemy. According to some experiments done by Sergbuto, you can achieve that by editing the torpedo properties
I would encourage to add a printable lead angle tables for the different torpedo and target speeds -a single Din A4 sheet will suffice-.
The firing method would such be as follows:
1.- On sighting the target, determine speed and AOB
2.- Turn your submarine to a perpendicular course to the target and start the fruit machine (The position keeper will do teh same job)
3.- Make several estimates of speed and distance until the Fruit machine shows teh same bearing you get with your scope. Pray that the bastard won't zig
4.- Look up in the table what deflection angle you must use. Turn your scope to that bearing and wait until the enemy goes into your crosshair centre to fire your torpedoes.
