The purpose of the investigation is to find the configuration of perforated baffle providing maximal liquid oscillations damping and minimal equivalent stresses in the road tank reservoir. The computational results showed that the maximal liquid energy dissipation corresponds to the 18–22 m perforation hole size and the area of holes should be 30–50% of the baffle area. Performed analysis showed that minimal stresses appear in the perforated partition of a convex shape with large radius of curvature at the central part and a much smaller radius in the area of connection to the tank shell.