Well, at least the train crews are not bothered by skeeters. That smoke will make anything drop out of the air. My old Navy Fairbanks/Morse O.P.s would smoke like that when we had a lot of fuel injectors not working right, due to no regular maintenance or bad diesel fuel. Alcos also, as I recall, would usually lay down a decent smoke screen, no matter what we did to try to fix it. I just figured it was a combustion chamber design problem, or sometimes a low compression pressure, resulting in poor ignition and unburned fuel being exhausted. My friend from Russia tells me that he ran into almost no pollution control problems, and never even thought about it, as it was just ignored. If someone complained, it became their own bigger problem.