Mr. Steam,

Yes, exactly - you got it. The winter was most likely for show, which impressed only railfans and confirmed to everyone else how great it was that these belching infernos are commercially extinct. I do not think any technology with a smoke stack is a good sell in an anti-industry economy like the US. A modern steam locomotive with conventional solid fuel combustion would certainly have to have a level of exhaust after-treatment which is difficult to achieve in the clearance diagram and probably negates mixing of the boiler and steam engine exhaust, the later of which will need to be condensed and reused to be an acceptable technology anyway, as most of the public believes water can be wasted (destroyed.) The end result would be a machine which the majority on this forum would content is not a steam locomotive because it does not conform the the Stephensonian scheme.

Regarding economics, I would suggest this paper:
http://www.trainweb.org/tusp/Coal%20Locomotive%20Final%20Paper.pdf

The link does not work.

The link should work now. I had deleted the file due to space limitations which were recently fixed. I have replaced the file which fixed the link.

Ross Rowland is a regular contributor to this forum; maybe he can fill us in on Steve's whereabouts.