General American had been building Airslide covered hoppers since 1954 but in 1965, a noticeable change was made to the design. Triangular gussets were added to the upper corners of both sides. Cars continued to be built with the gussets until the early 1980s. Airslide technology consisted of an air-permeable fabric lining the bottom of the interior of the car. To unload the car, compressed air would be pumped through the fabric and the load (usually powders such as flour) would slide down to the discharge gates.
 
Fully assembled, ready-to-run cars feature metal RP-25 wheelsets, working knuckle couplers and historic paint and lettering schemes.

GATX
Golden Leaf
Pillsbury
ATSF
PRR
N&W
CR
PC