In March 1960, the T&P received its first low nose units: GP18s 1145-1149, but they were quickly renumbered 500-504 in a general renumbering. The MoPac "Jenks blue" had been introduced in June 1961, so this T&P blue and gray scheme was very short lived. A few other units also received this scheme, including GP9 395 coupled to the 503 and GP9 398, which was also in the consist. The 503 eventually became MoPac 1853 and was retired in April 1984. Tornillo was located on the joint T&P-SP line between Sierra Blanca and El Paso, Texas.
