HMS Warrior is considered to be 'one of the first' true ironclads (if not indeed the first) - as she was equipped with a hull form, that was made entirely of iron:
Warrior's hull form, made use of iron, both internally (such as in her bulkheads and frames) and externally (such as in her 4.5 inch thick belt armour). For 1860, this was a marvellous achievement - as all preceding warships, had only ever been constructed, with wooden hull forms (including their bulkheads, frames and armour). Despite this, Warrior still needed to be based upon the warships of the past (such as HMS Victory) - so Warrior's hull from, was essentially a wooden design, that was constructed in iron! As such, it was expected that her manoeuvrability, would be similar to that of previous ships of the line - so she retained their clipper bow (which improved her sea keeping).