there's a way to mod this so they won't automatically open. Pretty easy to do actually. If I don't get a mod for this out someone else will soon I bet.
edit - so much for it being easy. It's either hard coded to open the door when you select a tube or it's not in the normal files for a submarine. Cause there's an auto-open setting in the sub files but changing that to No didn't make a difference. One of us modders will find it eventually
