|The configuration of coal trains flexes over time. Sometimes they run 2x2x1, then operating philosophy will change, and theyll go 2x3, then 3x2, then back to 2x3. For a long time, when the practice was 2x2x1, KCS would add helpers about 85 cars deep, leaving the home road power solo on the rear. Once again, we are in a 2x3 mode, and KCS has added their DPUs on the rear, which is where we find them on this southbound AEPX train crossing Cheri Whitlock Rd. Todays set includes a unit from south of the border.