The benefits if doing this is simple.
- diesel runs at more constant RPM which us better for life, fuel efficiency and emissions
- a smaller size diesel is needed
- no Aux motor is needed
- house power runs off a consistent cleaner supply, an issue the WA Prospectors had.
- less vibrations
The ability to go full EV is still a way off for Canberra services as its 270 km each way and only some recharging can be achieved while parked at CBR for 30 - 45 min turn around.
Might would on Hunter, but not longer haul Hunter.
Also cheaper option for Bombaderry services than 35km of OH and tunnel upgrades. Perhaps only partial OH where its cheap to do so and avoids need to change tunnels. So maybe a sub station at each station with a few km of OH in both directions to provide 5min of charge and power energy intensive acceleration.