The only way steams "thermal" efficiency makes sense, is through tubine use. Reciprocating steam locomotion is a costly maintenance problem. It is extremely labor intensive. The ability to use traction motors with a steam turbine is possible. The n=one "study" cited which showed maintenance costs of steam to be "lower" than diesel is refuted by hundreds of others on this subject my mechanical officers throughout the industry.

The problem with coal based "dieselization" is a real cost problem, not Sierra Club propoganda. Coal "liquification" is extremely energy intensive. Coal gasification, "in situ", may make more sense, and is also energy intensive, but far less so than liquification. I was involved in the methanol fiasco a few years ago. Touted as "fuel of the future" it took perfectly good natural gas, reduced its BTU equivalance 2/3 turning into a liquid that could be pumped with a nozzle into a tank. Only one problem it cost a fortune, and the buses were so underpowered they could climb a hill. Now we run all our buses in Southern California on natural gas directly at 30% less cost per gallon btu equivalence than diesel.

I've even been involved in a successful local application of hydrogen, made with "un-reliable" off peak wind power, that is used to power hythane buses, and peaker power plants (yes, you can store the wind?) But, today in 99% of applications of hydrogen take over 3 tiomes as much energy to produce than the btu gallon equivalent that it is replacing. So while I've been involved with a local application that was "cost effective" this is not a real economic solution for universal application at this time.

Electrification of railroads is a real solution used around the world today. Costs are high but known, benefits are well documented. Electrification takes a tax policy that rewards investment, not speculation in stocks, and this is one of the biggest hurdles this country faces. Our competitors in a world energy market reward long term investment for conservation and alternatives, and we reward short term stock trading? And, now we are paying the price.