Just a couple decades ago an entrepreneur was trying to revive the steam locomotive. Not the old kind, with the giant boiler and the big cylinders and tall driving wheels, but a New Technology one that resembled the diesel locomotives of today.
To make it even remotely competitive with diesels, they would have to have the same closed fluid system you (and the original article author) mentioned.
Even with a full sized locomotive chassis, They didn’t have room for a radiator that could get rid of fifteen megawatts of heat when running in “notch eight.”
Diesel locomotives of today consist of a diesel engine running a generator which powers an electric motor. No steam power involved.