Reliable steam created a new capital ship

Warrior’s much greater machinery output and higher speed show how far system dependability had advanced. Napoléon’s machinery offered useful assistance but repeatedly struggled to sustain her nominal full-speed endurance, whereas Warrior could operate at full power before requiring repair and careful maintenance. The ships’ very different displacement and speed figures need this operational context. Steam was an extra advantage in Napoléon but a central capability around which Warrior was designed. In a single decade, engine reliability had moved from permitting auxiliary power in a capital ship to defining a new capital-ship form.