I think that for this day and age, a fireman pursuing an "economy haze" is doing all of us a favor. Those big plumes of black smoke bring out all sorts of @#$%&'s nowadays, and who needs them?
I think that it's probably an impossibility to fire coal with a clean stack, but much of that is dependent on where the coal is from. Clean burned coal and oil smell pretty good (well to us anyway) but overfiring both is just a mess. If you like overfiring, ride on the tender deck and have the engineer lay that cloud over you. 'Nuff said.
Michael Seitz
Missoula MT
(who watched an oil fired tourist line evolve from black stack to economy haze and wouldn't tell them to go back).