This car is class F41 built between December 1955 and May 1956. 500 were built and numbered #469500-469999. Another 200 #469300-469499 were built between November and December 1956. They had a capacity of 70 tons and were general service cars, 53′ 6″ long over the end sills. The F41 was constructed on General Steel Castings’ integral cast steel underframes, and featured four cross-bearers, compared to two previously used on the F30A and F30D. These cars were equipped with 16 stake pockets and 15 lading strap anchors on each side sill as well as four stake pocket and two lading strap anchors on each end sill and had a wooden floor with a deck height of 3″ 5 1/8″ above the rail. Many received racks for hauling auto frames or auto parts. At least one car #469585 was also modified with Invert- A-Bin racks for hauling sand. Although confused with Commonwealth cast steel flats ordered by dozens of other railroads the F41 was a unique design. Differing from the Commonwealth casting, the F41 featured a different bolster and end deck configuration, two exposed steel stringers that ran part way along the length of the deck inboard of the bolsters, and shallower end and side sill profile outboard of the bolsters. The F41 rode on ASF Ride Control A-3 trucks.