Oops. sorry i didnt phrase it better.. i mean as opposed to scrapping them, is that the reason( to exploit the high level of damage that the 16 inch can do to modern vessels potentially ) other than NGFS that the USN mothballs them?
If there were a emergency scenario happening, like the outbreak of Korean/middle east(possible flashpoints in the future), would the battleship undergo emergency upgrading(radars, CIWS, VLS with SM and sea sparrows to make them more relavent should they be called upon?
What kind of upgrades would the USN give the mothballed battleships potentially should they see service?
None, nothing. Those ships haven't moved under their own power in twenty years and when they were active, they relied on oil fired boilers generating very high pressure steam to run steam turbines. That's a manpower intensive setup and as AegisFC said, the training school for that particular plant went away with the BB's. They'll never move under their own power again.
Put it this way, if you parked up a fifty year old car on your drive, and once a year, painted over any rust, put some air in the tyres and changed the air freshener, but did nothing else, would you expect it to run?
The ships were comprehensively stripped for useful materials before being decommissioned and that's a brutal process - most of the museums taking such ships on spend months just getting some spaces back to the standards a vewing public would pay money to see.
Just getting the ships moving under their own power would be millions and months.
It'd be quicker to build new ships with lower manpower requirements to fulfil whatever role was required.
Any emergency would be over before any of the BB's could be refitted and crewed, let alone worked up as a functioning military unit.
Besides, I honestly feel that if a magic wand were waved and all four were restored to "as new" condition for free, the smartest thing the USN could do would be to SINKEX the lot rather than be saddled with the expense of running them.