<p>The mountain tram running on the steep and sharply curved roads consists of three carbodies and two bogies. Since the middle carbody is supported solely by the couplers without a bogie, excessive pitching motion may occur. To address this issue, a connecting structure between the carbodies was proposed. The design process involved theoretical static and dynamic analyses using simplified models, allowing for the derivation of simple formulas to describe the pitching motion. These formulas were validated through numerical analyses, which provided the required stiffness for the upper coupler of the connecting structure to ensure the allowable pitching displacement was met. The upper connector was designed as a coil spring capable of absorbing large strokes. The detailed design of the spring was finalized based on the design formulas, enabling manufacture of the upper connectors. With this structure in place, pitching motion was effectively controlled, allowing the tram to maintain horizontal stability.</p>