I found the first video to be a bit boring....but my Orang Tabby Cat, "JR Mewing" was intrigued and kept trying to catch the Rotor Blades flashing by at the top of the screen!
I would think the North Sea thing is being over blown beyond the Gearbox loading being fairly high but constant for long periods of time.
The stress on a Gearbox in Underslung work like Logging would be far greater in stresses I would imagine.