In the early 1950's General American and Evans Products teamed up to produce a state-of-the-art plug door boxcars cars to a unique design. These cars featured two large horizontal panels on each side of a 7'-7" door. These panels were joined with a horizontal rivet strip that gave these cars a very unusual and unique appearance. This style of construction created a side with many feer seams than a standard boxcar and thus supposedly had less areas prone to rust or leaking. Between 1954 and 1959 a fleet of 1,025 50' plug door boxcars were built with this method. These cars were classified as AAR class "RB" or "RBL" meaning "bunkerless refrigerator car" (no ice compartments).

50’ plug door boxcar kits feature: 8' plug with seperate latch bars, 7 or 8 rung ladders, overhanging diagonal panel roofs, accurate postwar ends, and accurate paint and lettering.