A hatch cover for a covered hopper railcar includes a substantially circular shell member having a radially outer circumferential perimeter. The substantially circular shell member includes a topside surface and an underside surface. The hatch cover also includes a downwardly extending rim member coupled to and unitarily formed with the substantially circular shell member. The substantially circular shell member and the downwardly extending rim member define a shell/rim interface at the underside surface. The hatch cover further includes at least one sealing gasket fixedly coupled to the underside surface proximate the shell/rim interface.