Diesel, regardless. They're just dull, noisy and an eco-disaster-zone. Keep steam because it's fun, nicely sonorous and low enough quantities to not be a significant eco-threat (we could always heat the water some other way - see Electric below). Day-to-day use electric because it's quiet, clean and efficient (but quite dull). Internal generation from fuel cell or maybe fission (in 20 years of course) because cables suck aesthetically, reliabilityally and infrastructurally.
Diesel, regardless. They're just dull, noisy and an eco-disaster-zone. Keep steam because it's fun, nicely sonorous and low enough quantities to not be a significant eco-threat (we could always heat the water some other way - see Electric below). Day-to-day use electric because it's quiet, clean and efficient (but quite dull). Internal generation from fuel cell or maybe fission (in 20 years of course) because cables suck aesthetically, reliabilityally and infrastructurally.
