According to some embodiments, a refrigerated railcar comprises a pair of side walls, a roof, a floor, and a refrigeration unit. The floor comprises a bottom structure comprising a plurality of channels for return air flow from an interior of the railcar to the refrigeration unit. The floor further comprises at least two top plates coupled to the bottom structure (e.g., via a pivot rod). Each of the top plates extends longitudinally along the bottom structure and is configured to rotate up and away from the bottom structure proximate one of the side walls of the pair of side walls. Lifting an edge of a top plate opposite the edge of the top plate pivotally coupled to the bottom structure causes the top plate to rotate to an upright position exposing the plurality of channels of the bottom structure.