Some pertinent technical questions from folks like
fdr & barit1
e.g.
Highly technical answers regarding shaft separation and overspeed, are best handled in Tech Section and not appropriate to confuse R&N armchair designers.
The overspeed issue has two competing ingredients
* the compressed (spring) gas pressure aft of the compressors and already destined for the turbines
* the enertia of the turbine spools as well as their gas loads pushing a seperated rotor into the stationary vanes
there other equally significant design effects which I won't get into here
The simple answer to Barit1 question is No
The HPT will likely overspeed by a factor of two in about 1 sec
The IPT in about 2 sec
and the LPT in about 4 sec
I'll bow out of the discussion now and the only reason I even answered was because several posts continued along the same line.
PS fdr there are lots of data sources on uncontained discs but forget about using statistics with the regulators
pps, we probably shouldn't even be talking about overspeed in this A380 thread since overtemp at constant speed is still under investigation as well