The B-end of car DJJX 30478 […] was relatively intact but was surrounded by scrap steel lading from the car, which had been released to the track surface […] The bathtub gondola car structural features produced a car that could carry more lading and provided a relatively obstruction-free car interior which, when combined with the rotary dump feature, permitted the free-flow of granular lading and rapid evacuation of the load with little or no residue left in the car.