[GDFTigerTank]

There's no reloading the rear tube on a Type VIIA without either a Milch Cow or a Port Facility with hoists and winches.

You leave port with a torpedo in the tube.
It's one shot and you're done.

Hence no reloading animation.
Hence no torpedo to see.

It fires and all you have afterwards is indeed an empty hole.

Actually found an old photo a while ago of a torpedoman who made his bunk in the tube after it was empty. I hope the crew didn't close the hatch on him as a prank! - note this was on a VIIB or VIIC where the torpedo tube is an INTERNAL mount.

Note: Actually don't know if reloading the aft launcher from the fore torpedo reserves is possible in game - but it should not be, and it wasn't in real life. So the lack of reloading animations is fine in my book. The aft torpedo is always the last torpedo I shoot because it is my ace in the hole.