Derek:

In order to rotate a tube-loaded torpedo, it must be withdrawn from the tube far
enough for the "guide-stud" to clear the guide slot in the upper central part of the torpedo tube. Extreme caution and cooperation with the diving officer is mandatory
when this evolution is carried out. NO DIVE ANGLES! This evolution was frequently necessary to vent the accumulated hydrogen from the battery compartments of the early MK 18 battery-powered torpedoes during WWII. A later
modification provided a small "hydrogen burner" placed in the battery compartment
to "burn-off" the hydrogen. This composed of a small nichrome wire coil in the battery compartment and a power supply and control cabinet in the torpedo rooms.

Later, in the MK 28 acoustic torpedo, a palladium catalyst replaced the nichrome
wire, and this required no power supply or control cabinet.

Now getting back to a torpedo being turned over to access the gyro and depth control (Uhlan gear)........This generally can be accomplished while the torpedo is in its "skid" by passing a special 3/8" diameter wire-rope cable around the unit and
attaching both ends to a 40" long steel-pipe "sluing-bar" to rotate it. Acess to these components is also possible for a tube-loaded unit as previously described.

Torpedoes are by design "ballasted" to prevent them from "turrning over" after being launched. By ballasted, I mean that heavy components like the 80# brass base-plate of the exploder mechanism, the gyro housing containing the Gyro and Depth control mechanisms are all mounted below the center of gravity, and the counter-rotating screws contribute to preventing a "turn-over" of the torpedo after
launch.

Hope this helps to explain tthe posibility of "turn-over".

Regards,

ROBERT M.