Bridge cranes carrying structure is one of their essential elements. The most popular, solid-walled metal sheet structures have higher mass that leads to a stable trend in metal reduction. Due to the wide range of loadings, mass reduction calculations are faced with various problems that could be solved effectively by an appropriate methodology, as the one proposed here. The underlying techniques in the methodology are 3-D computer models and mathematical methods such as FEM, the matrix exponential, Newmark, Kutta-Merson, FFT, etc. realized by ANSYS, MATLAB, visualNastran,...