Were the tubes always loaded?

If there were still enough torpedoes on board, yes. The tubes would always be loaded at the beginning of a patrol. As torpedoes were fired, reloads would be moved into the tubes as soon as practical. Torpedoes would not normally be moved when under attack. The normal routine was first to escape. Then the submarine would be submerged so that there would be less motion from swells. That’s when they reloaded the tubes.