One of the major railcar leasers in North America is GATX (General American Transportation Corporation). A set of six brand new DOT111A100W7 GATX tank cars with head shields, roll south on Brenco bearings in the mixed freight of CSX train Q678. These cars were constructed with either, high alloy steel or manganese molybdenum steel. Shiny and clean now, but in a few weeks they will become dirty blending in with the other fleet of railcars that bear the markings of a life on the railroad. List of GATX tank cars numbers... 220391, 220401, 220397, 220396, 220398, and 220394.