Wrong way, westbound (north?)... more than 60 cars I think... a lot of loaded hoppers, maybe 20-30 of these alone, I noticed because they're piled pretty high and I would think generate some debris if they're not wet down before leaving. A number of tank cars, unknown contents, and a number of carbon dioxide tankers too. It was odd the way it was assembled, several hoppers, other stuff, more hoppers, other stuff, and ended with auto racks and center-sill lumber carriers.
Ten minutes was my grossly high estimate of time... yes, I would say 25-30 mph, and maybe 5 minutes!