Titanic Censorship

So, I was watching the IMAX titanic movie...not the James Cameron 3D one, the other one. And as I am, I notice something odd...two instances, one a photo, one a film clip, where something was scratched out back-in-the-day.

Titanic Worker Erased From History - This image shows a worker who was erased from a picture. You can make out his outline, and shadow on the pipe, but no clue who it might have been, or why he was removed...

Titanic Tugs Names Erased From History - This image shows how in the film-clip, the tug-names were scratched out.

I'm most curious what happened, the why behind these edits, and why a documentary would use them without giving some sort of explanation. Oh well.