 The entire side of the Minotaur @-@ class ships was protected by wrought iron armour that tapered from 4 @.@ 5 inches ( 114 mm ) at the ends to 5 @.@ 5 inches ( 140 mm ) amidships , except for a section of the bow between the upper and main decks . The armour extended 5 feet 9 inches ( 1 @.@ 8 m ) below the waterline . A single 5 @.@ 5 @-@ inch transverse bulkhead protected the forward chase guns on the upper deck . The armour was backed by 10 inches ( 254 mm ) of teak . 
