Westbound double-stack container train at milepost 520 slowing for a meet with BNSF 4621 East at Callahan. Locomotive power was BNSF Dash 9-44CW #982 and 5236, Transportacion Ferroviaria Mexicana (formerly Ferrocarriles Nacionales de Mexico) C30-Super 7N #2302 and Norfolk Southern Dash 9-40CW #9375.