I've finally found a workaround and fixed the bulkheads collapsing sounds when a ship sinks. It's always been broken in SH4, and you could only hear the sounds if you were within just a couple hundred feet of the sinking ship. So basically, you never hear those sounds. Being a hard-coded bug, adjusting the distance and volume made no difference. That's one thing I always missed hearing in Silent Hunter 4... those death creaks and moans when a dying ship sinks. Really adds to the atmosphere of the game. Creepy.
The fix works really well, and I will be including it in the next update of Traveller Mod.