A generic model of it railway car body in sandwich design was weight optimized subject to various constraints. These constraints were global natural frequency constraints. buckling and wrinkling constraints, and sound reduction constraints. A finite element model was used for global analysis. while sandwich plate theory was used for local structural analyses. The acoustic model for sound reduction was a sandwich plate model. The optimization procedure started with an infeasible initial design and produced it final design which fulfilled all requirements. yet had a reduced weight. The optimization wits performed with and without acoustic constraints and the results imply that the acoustic requirements will produce a heavier design than when the optimization is performed with mechanical constraints only.