I stumbled across this
http://www.navweaps.com/index_tech/tech-038.htm and whereas it is clearly nothing new, I hadn't heard of it and it does pique some interest.
The summary is that several large ships (aircraft carriers, ocean liners etc) had a propulsion system that utilised high speed turbines driving generators with electric drive to the props.
This means that a high speed turbine can be used with low speed props - efficient for both without an inconvenient gearbox. Reversing can also be electrically arranged and so no reverse turbine is needed.
This might have interest to those who wish to build a steam turbine warship using (for e.g. as I have read here) dental turbines or the like but are finding the gearing a problem.
see also
https://en.wikipedia.org/wiki/Turbo-electric_transmission
