Mt. Washington Cog Railway Surviving Steam - Trains Magazine

Interesting numbers.

15 gallons of #2 Diesel is 105 pounds of fuel.  The steamer is then using 2000 pounds of fuel, or 19 times as much.  Coal varies a lot in BTU content, but let's say 14,000 BTU/pound vs about 20,000 BTU/pound for a wide range of liquid oil-based fuels -- this puts the steamer at about 13 times as much equivalent fuel.

The Diesel is what, 35% efficient?  This puts the steamer at 2.7 percent efficient?

Of they are evaporating a thousand gallons of water with a ton of coal, they are evaporating 8000 pounds of water with 2000 pounds of coal or 4 pounds of water per pound of coal.  This means they are using 3500 BTU to evaporate a pound of water, which in vapor state has a heat value of anywhere from 1000-1400 BTU, depending on the boiler pressure and amount of superheat.  This tells me that their combustion efficiency is in the range of 29-40 percent.  That is, they burn 2-3 BTU's of coal to get a BTU of  steam.

Maybe the full Chapelon-Porta-Wardale (Gas Producer fire box, superheat and a lot of it, low-restriction steam circuits, saturated-steam cooling of valves, low-restriction exhaust system, compound expansion) treatment is misplaced on this one tourist steam engine.  But suppose they reduced coal usage from 2000 pounds to 700 pounds per trip (8 percent thermal efficiency -- I believe that some of the mainline steam engines -- T1, Niagara, J-class could do as well)?  Would this make a difference?

If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?