more details....

That spot is always a bit smokey. The engines are just easing off after climbing the first short stretch of 3-4% from the Yard Limit. The firemen have been busy getting thier fires in shape, getting the injectors running, etc. The the the hogger eases off on the throttle... instant smoke and lots of it. Add to it a nice 10 mph wind out of the south east to roll the smoke nicely, and as they say "even a blind squirrel finds a nut occasionally".
When I entered the shot in the contest, the judges said "man look at that smoke, those engines are REALLY working". Little did they know, you could hardly hear 484 when it went by... Looking at the rest of the chase shots that day it was the only shot I got with both engines smoking hard.
John Krause once said "the rarest thing on Cumbres is a 3 engine freight with all 3 engines making smoke." Well, 2 is sometimes tough too..