Why do submarines generate electricity at 60 hz What happens if they generate at a lesser frequency?

US submarines generate 60 hz... not sure about other countries. 60 hz is the US Standard. That pretty much sums it up. If they were to generate a different frequency such as 50 hz then the electrical motors would turn a bit slower. Also if the motors were rated at 60 hz and were ran at 50 hz then the volts/hertz ratio would be off resulting in over excitation of the windings and slight loss of efficiency and possible overheating.