These 40’ standard box cars with single doors are painted black with aluminum sides. They bear the SP Daylight Orange circular heralds with SP Daylight Red ‘S’ and ‘P’ and ‘Overnights’ lettering. They were built by Mt. Vernon Car Co. in June 1946, serviced in West Oakland, CA, in February 1956, and run on Bettendorf trucks. The SP continued to use the 10’ interior height cars due to restricted line clearances in a few locations. The silver ‘Overnights’ paint scheme was adopted in late 1955. The word ‘Overnights’ was dropped in 1957 and in 1958 the herald was changed from orange to Daylight Red.