I'm sure I've done this before, but never noticed. I was desperate for torps to attack but all my aft tubes were damaged. When I dragged the torps back to the storage slot, I got the message they were unloading. The torps unloaded just as they loaded showing percentage over time as they unloaded..
Course when they unloaded they just started reloading again. It sure would be nice to unload them to the storage slots, then with auto load off, you could choose what tube to place them, that way if one tube was good, you could actually use your torps as you would in realistic battle.
Just seeing that they can unload, wonder if someone could mod it to work as it should.