I was doing a bit of research into the MoPac heavyweight baggage and mail storage cars built by ACF to a common design, the one produced by Walthers. See the Carson Houston article on these cars in the Eagle, Spring-Summer 2007. It occurred to me that I could summarize the modifications to these cars as documented in photos and MP equipment diagrams. I’m primarily interested in the era of the late fifties, just before the major cutbacks in passenger service began, and before the replacement of many of these cars with the 150 new lightweight mail storage and express cars.

Painting of these cars into Eagle colors began around 1948, but many cars were shopped after that time and received various modifications and improvements. Many of the cars received skirting of several basic types, and a few seem to have had some of the skirting removed again. The roof modification to look more like a lightweight car with smooth contours was also done over time, so the number of cars with this feature gradually increased. Toward the end of the Eagle paint scheme, some simplification of the painting occurred. The door changes were no doubt due to wear on the original doors, and subsequent replacement with an improved door design.

Between the excellent photos in the Eagle article and others I have acquired, plus photos that have appeared in books, I was able to document about 50 of these cars as to their appearance. The spreadsheet attached is very much a work in progress, and I invite comments. Note that some photos of cars in the Eagle paint scheme were taken early in the 1950s, and sometimes there is another photo of the same car, from several years later, showing several modifications not present in the earlier photo.

Brief explanation of the designations —

All of the data in the columns for skirting, roof shape, doors and paint notes came from photos or equipment diagrams. Other roster data is taken from the Eagle article. The spreadsheet that accompanies this issue of the Eagle has much more data on car dispositions. The spreadsheet here is intended primarily to account for the appearance of the cars.

For skirting, some cars had skirting between the trucks and not at the ends of the car. Others also had a small skirt between the corner steps and the truck, while others had a larger skirt section with a single corner step below it, with or without the skirting in the center of the car. Others had a continuous narrow skirt shaped like a quarter-round, similar to the skirting on mid-50s lightweight cars, and a wider skirt section at each end. Still others had no skirting, but did have a reinforcing plate riveted below the door that extended somewhat below the car side.

Roofs are self-explanatory, without an attempt to track the exact number and placement of vents, which also varied between similar cars. The arch roof, except for those few Gulf Coast Lines cars built with arch roof, was overlaid on the existing framing. Viewed from the side, there is often a perceptible overlap of the roof sheets beyond the plane of the side, on rebuilt cars. The “Texas roof” is similar, except that instead of a complex curve there is a vertical sheet with angled sides, directly above the car end sheets, and a taper from there to the top of the roof which gives the impression of a transition from the cross-section of a streamlined car roof to that of the heavyweight car roof. It should be noted that several other railroads, UP being among them, also used this design extensively in modernized heavyweights.

Doors were replaced with a more modern steel-faced door containing a gasketed window with curved corners, the same design that refurbished lightweight cars got. There is evidence of at least one car that had one of the doors replaced but not the other.

Ron Merrick