Between 1972 and 1973, Penn Central received the first of over 1065 boxcars in the X72/X72A fleet from US Railroad Manufacturing's (Evans) Blue Island, Illinois plant. These cars would eventually find their way to Conrail in 1976, retaining their PC numbering series while getting CR reporting marks. Some cars received full repaints, while others received just patch jobs. After toiling for many years with Penn Central/Conrail, CN acquired a substantial portion of the remaining fleet, many of which were sold off to leasing companies more recently.
The only subclass of the X72 was the X72A. As pointed-out by Jim Six in his Railroad Model Craftsman article, there appears to be no external distinction between the X72 and X72A. Both cars have same welded 12-panel construction and feature 6-panel Superior doors.
The X72 is a general purpose boxcar that can be found in nearly every service, making it a very common piece of equipment throughout North America. Some cars are equipped with DF Belt Loaders for assisting in loading and unloading of special equipment, while other cars are equipped with Dual Air Paks for in-shipment shock control of goods and pallets. These specially equipped cars are in assigned service to specific industries for specific loading.
