I looked all through my 1953 Car Builder's Cyc and I couldn't find anything that identified the "heap shields" by name <
diagrams for hopper cars. Some use the term "heap capacity" to describeThe term maybe railroad specific as I have seen it used on equipment
the additional capacity over a level load. The B&O used the term
"piling". <<FWIW, earlier today while perusing a 1943 CBC, a drawing of an AAR Class HM 55-Ton all-steel twin hopper car presented by Enterprise Railway Equipment Co. carried, in part, this description:
"Cubic capacity, 2,139 cu. ft. level or 2,455 cu. ft. with 12 in. average heap."
(So, is this an Enterprise car design, I wonder, or an AAR car design with Enterprise's tag, since Enterprise hoppers and bolsters were used in the drawing? Or something else? . . .)