Fort Pickens had become outdated because new rifled artillery could penetrate its brick walls. In 1898, the U.S. Army revived the old brick fort by building the reinforced concrete Battery Pensacola inside it. This fort within a fort mounted two 12-inch rifles on carriages that could disappear behind the walls after firing 1,070-pound shells at ships eight miles away. The Army also built several other batteries on this end of Santa Rosa Island in the late 1800s and early 1900s.