The Audacious-class ironclads were laid out as central battery ironclads with the armament concentrated amidships.
They were the first British ironclads to have a two-deck battery with the upper deck guns sponsoned out over the sides of the hull.
The ships were fitted with a short, plough-shaped ram and their crew numbered 450 officers and men.

HMS Audacious was 280 feet (85.3 m) long between perpendiculars.
She had a beam of 54 feet (16.5 m) and a draught of 23 feet (7.0 m).
The ship was first British ironclad to be completed below her designed displacement; this meant that she was top heavy and required 360 long tons (370 t) of cement ballast to raise her metacentric height.
Audacious, and her sisters, were the steadiest gun platforms among the large British ironclads of their era.
Audacious was given an experimental zinc sheath for her hull in an attempt to reduce biofouling that proved unsuccessful.
The Audacious-class ironclads were laid out as central battery ironclads with the armament concentrated amidships. They were the first British ironclads to have a two-deck battery with the upper deck guns sponsoned out over the sides of the hull. The ships were fitted with a short, plough-shaped ram and their crew numbered 450 officers and men.
HMS Audacious was 280 feet (85.3 m) long between perpendiculars. She had a beam of 54 feet (16.5 m) and a draught of 23 feet (7.0 m). The ship was first British ironclad to be completed below her designed displacement; this meant that she was top heavy and required 360 long tons (370 t) of cement ballast to raise her metacentric height. Audacious, and her sisters, were the steadiest gun platforms among the large British ironclads of their era. Audacious was given an experimental zinc sheath for her hull in an attempt to reduce biofouling that proved unsuccessful.
HMS Audacious (1869)