awblain Energy of disk ?
I would put the diameter of the HP disc closer 1.1 meter and the weight(mass) around 75 kgs + with blades fitted
The IP disc is larger again but not as thick but I suspect a similar mass.
I remember as an apprentice building up modules that the turbines discs were light enough for 2 people to lift but we didn't as they needed to be put down very gently to protect knife edge seals on the faces
Now the RR G2 N3 spins at approx 12,000 at 100% at climb thrust the N3 would still be above 90%.
Using "awblain" formula above. As "barit" said you don't want to be anywhere near it if either let go. I
Would suggest a harmonic vibration has stress fractured the oil lines. This takes us back to 1950s failures
From what I am hearing its not fractured tubes or oil supply issues. Think along the lines of the hot area bearing fire. RR use labyrinth seals and looks like the high temp air could be getting into the HP/IP Turb bearing compartment cooking the oil causing bearing seize or failure.
This could explain why RR have asked to look at turb blades because if the oil is getting out perhaps the hot air is getting in where it should not.
Just my interpretation of the AD