In the past decade, search robots in rescue operations have been focused on and developed for the purpose of finding survivors trapped in the rubble of collapsed buildings. However, serpentine mechanism which is a popular mobile system might gather to catch debris between tracks or become stuck due to the mechanisms, in addition, increasing the number of segments would result in gaining weight and complicated control system. We have, hence, proposed a new mobile mechanism: flexible mono-tread mobile track (FMT), and developed a prototype ldquoRescue mobile track No.2 (RT-02) WORMYrdquo. In the paper, a dynamic model for the FMT is derived in a sagittal and lateral plane to treat the movements. Then, some simulation are shown to analyze the lateral movement with respect to various pressure distribution affected by the retro-flexion. Finally, the analysis is validated through some experiments.