Operating Era: 1920-1950. Atchison, Topeka & Santa Fe, Santa Fe Refrigerator Despatch. Santa Fe used the USRA reefer design, stretched to 41'3", as its standard for the decade of the 1920's. The first delivery was 2,500 cars, half from American Car & Foundry and half from Haskell & Barker. The cars kept the odd ventilators used on previous truss rod classes. All subsequent classes use normal hatches, although opening opposite of other roads. RR.X retained the roof clips of RR.W but used the smaller herald. 2,500 cars were delivered in 1922, 1,250 each from AC&F and Pullman, series 15451-17950. As with RR.W the cars were rebuilt with steel superstructures beginning in 1936. However, the program took until 1950 to complete. Kit 8602 covers class RR.X cars in all physical and lettering styles from delivery to rebuilding.