said by disconnected :
I find it hard to buy the concept that they are that inefficient. I rode Flagg Coal #75 from Thomaston all the way down to the middle of the state and they did it on one load of coal. That was moving many tons of train cars. I cannot imagine that generating 20HP would burn a cord of wood a day.
Very inefficient compared to turbines.
A full size mainline engine could produce about 1500kW with a 300 psi boiler and a superheater, burning high grade coal.