The leading cab of the rolling stock receives the greatest impact when frontal crashes occur. It has a complex structure due to the concentrated loads it must resist, and a need exists to enhance its performance while minimizing the weight of the cab. Therefore, during the design phase, the optimal material arrangement to enhance structural capacity should be sought. Here, topology optimization is applied to the design of a protective shell frame to enhance crash energy absorption. The design performance during a crash is then compared with the original shell frame design. The crash analysis of this research is performed using a finite element model consisting of an optimized/initial protective shell frame. The frame is tested in an accident scenario (crash at 110 km/h against a movable rigid mass of 15 ton). The results of the crash analysis validate the use of topology optimization in the conceptual design phase.