If I have conducted the correct approach I should be between the lines and moving in the same direction of the convoy, albeit slowly (Let them catch me). So I can shoot two salvoes of two torpedos at a 90º and 270º Gyro Angle and hit two targets. Rear torpedo tube comes not in question because with manual targeting it is too difficult to compensate the parallax without an accurate range reading
so I follow UBoat Commander's Handbook advice and don't use it in running fights
If I failed in my approach or the convoy zigged, I tend to look for the 90º AOB and shoot a salvo at two ships.
P.S. I wish convoys had a bit more separation between lines and escrots were farther away to allow more real-life tactics, but as they are in SH3 (Specially the escorts, because GWX corrects very well the spacing for large convoys
) you usually find that browning shots from outside the escrot screen work reasonably well :hmm: