Ships Cover for the Audacious class and Swiftsure class central battery ironclads HMS Audacious (1869), HMS Invincible (1869), HMS Swiftsure (1870) and HMS Triumph (1870). The documentation is of a varied and general nature, but primarily comprises statements of dimensions and weights, stability calculations, details of refits and other alterations, armament and ammunition allowance, design specifications, and schemes of complement. There are also a number of design papers relating to the Minotaur class broadside ironclad HMS Minotaur (1863). The earliest papers date from June 1861 (for Minotaur), and the last from December 1905, by which time the four ships to which this Cover primarily pertains had been hulked for static duties.