Has there ever been a 'study' on whether zigzagging was effective against subs.? Is it still practiced today?
I don't know whether any study was made, but I'm quite sure from my naval wargaming days that zigzagging plays havoc with firing solutions. With unguided torpedoes you have to consider a lot of variables, such as target speed and direction, your won, torp speed, angle of median target trajectory related to your own course, etc. Some of these are estimates, especially the target related ones, so there are already error margins built in. If you have a target changing course, then this becomes an almost impossible task. You shoot a spread of all your tubes and pray, which means either you run out of ammo early besides risking broaching or else you let that one go and wait for a target in a hurry, who is running straight ahead.
Yes, there were studies made by the Allies on this and other related stuff. See: Methods of Operations Research by George E. Kimball and Philip M. Morse, Peninsula Publishing, Los Altos CA 1970 for example.
I think that in one book on the U-boat action there was some talk that after checking the convoy movements for a while the sub crew easily could identify the turning points and suggest where the other subs should go. I guess the zígzagging also slows down the convoy but I guess it´s the best you can do. If the destroyers can spot the subs fast and engage them then the subs don´t have time to calculate the convoy´s movements and then the zigzagging is working.
