Santa Fe (ATSF) #49502 50' Combo Door Boxcar HO scale RTRDetails: Roadnumber in the image may be incorrect. These 50 6 box cars were built in the 1960s and featured a combination of 8 0 Youngstown sliding and plug doors. Combination door boxcars had the advantage of being both a standard box car with sliding door, plus having a larger opening for larger loads. The plug doors provided internal flush side walls along their location next to the sliding door. Having these flush side walls increased usable cubic