The United States Navy's Boston class were the first guided missile cruisers in the world. Both ships in this experimental class were originally Baltimore class heavy cruisers that had been decommissioned after World War II, but were redesignated as guided missile heavy cruisers (CAGs) and entered refit in 1952. The lengthy conversion and modernization project involved removing the aft triple 8-inch gun turret and its supporting structure and installation of two twin launchers for Terrier anti-aircraft guided missiles. The forward two 8-inch gun turrets remained unchanged. The forward superstructure was modified to include the Terrier's associated radars and electronics, the aft superstructure was completely replaced, and Baltimore class's two funnels were trunked to one.