3480842 Formidable was an Amiral Baudin-class ironclad battleship of the Marine nationale, 1890; (add.info.: Formidable was an Amiral Baudin-class ironclad battleship of the Marine nationale (French Navy). In 1890, Formidable was used to experiment captive balloons usage in the Navy. [1] In May 1891, she became the flagship of the Mediterranean squadron. In 1898, she was transferred to the Atlantic squadron, based in Brest.); Universal History Archive/UIG; out of copyright.