The rapid evolution of warship design, for which "Warrior" was partly responsible, meant that she started to become obsolete only ten years after she had been launched. In 1871 the Royal Navy commissioned its first mastless capital ship, . In the absence of masts, the main armament could move from the broadside and traverse more freely from a higher position. In the same year, "Warrior" began a refit that lasted until 1875; it added a poop deck and steam capstan, a shorter bowsprit, and replacement boilers. In April 1875, the ship was recommissioned, and assigned to the First Reserve, where she served as a guardship at Portland. In this role, she went on annual summer cruises to various ports. During the Russo-Turkish War of 1877–1878, she was mobilised due to concerns that the victorious Russians might be about to attack Constantinople, forcing Great Britain to intervene, but nothing transpired and "Warrior" cruised to Bantry Bay instead. In April 1881 she was transferred to the Clyde District, where she served as guardship until 31 May 1883. Two of her masts were discovered to be rotten that month and with no replacements available, the ship was decommissioned and the masts removed.