Here is a couple of links,
This one talks about the use of torpedos in real life
http://www.geocities.com/thomasdclayjr/Torpedoes.html
This one list all types developed, used or experemental
http://www.navweaps.com/Weapons/WTUS_WWII.htm
The reason why with give such great infomation is that we all love the game, the history and the enjoyment of passing it along to all who want it.
We do make mistakes, but the others will set us back on the straight and narrow.