correct, you cant burn anthracite in a locomotive designed to burn bitty it will burn out the grates. head up pioneer tunnel they burn anthracite and there is actually really no visible smoke, its steam youre seeing coming out of the stack. how it works is the exhaust from the cylinders blows up through the middle of the stack creating a venturi if you will that sucks the smoke from the fire box through the flue tubes in the boiler heating the water then the "smoke" is sucked out the stack. as you anthracite burners know there really isnt any smoke coming out of your stoves, its the same thing. so those puffs you see are the exhaust steam from the cylinders. on a steam engine burning bitty its the same thing except the steam sucks that black smoke out of the fire box from the dirty bitty coal and it comes out the stack with the steam. look in the smoke, you can still see the steam in it.
locomotive burning anthracite:http://www.undergroundminers.com/ashland5.jpg
Locomotive burning bituminous: http://mst145.rrpicturearchives.net/sho ... id=1155198