Reference: This question from Worldbuilding.
I'm writing a time travel story set in 1962 and I'm in need of an analogue to Doc Brown's plutonium (or bolt of lightning!). What I settled on for my inventor's 'contraption' was flywheel energy storage. To be precise, two counterrotating 830 lbm 60" rim diameter flywheels constructed (mainly) of martensitic steel operating at a maximum speed of 5000 rpm.
My specific questions are: Would this be feasible and reasonably safe with late 1950s technology, and could the RPM be increased without shaving the factor of safety too greatly? The device, for fictional purposes, is being installed in a DC-3; while it's not practical to increase the radius/diameter an increase in RPM would permit less flywheel mass and thus more useful load.
Please note that I'm postulating that the "activation energy" which opens the time continuum is not frequency-sensitive and so it is possible to place windings directly around the flywheel to generate the pulse. The "sustaining energy" which keeps the object stable in the time continuum, though, is very frequency-sensitive and is supplied by a separate, governed alternator. However, its power requirement is much less and can be continuously supplied by a gas turbine APU (available from 1956 onward).
