HMS Zealous was one of the three ships (the others being and ) forming the second group of wooden steam battleships selected in 1860 for conversion to ironclads. This was done in response to the perceived threat to Britain offered by the large French ironclad building programme. The ship was ordered to the West Coast of Canada after she was completed to represent British interests in the Eastern Pacific Ocean. Zealous became the flagship for the Pacific Station for six years until she was relieved in 1872. She was refitted upon her arrival and subsequently became the guard ship at Southampton until she was paid off in 1875. The ship was in reserve until she was sold for scrap in 1886. Design and description HMS Zealous was given a straight stem and a rounded stern, but her hull was otherwise unmodified from her original form; it had been found that lengthening the hull, as was done in the earlier , led to longitudinal weakness. Her conversion to a central battery ironclad therefore cost less than that of any of her contemporaries, though this was offset with a shorter battery and therefore a less effective broadside. She also carried less armour than the earlier class, and was nearly a knot slower; however, as she was built to serve in distant waters, and not expected to face opposing ships of significant force, these shortcomings were thought acceptable. Zealous was long between perpendiculars and had a beam of . The ship had a draught of forward and aft. She displaced . Propulsion Zealous had a simple horizontal 2-cylinder horizontal return connecting-rod steam engine driving a single four-bladed, propeller. Steam was provided by eight rectangular boilers at a working pressure of . The engine produced during the ship's sea trials in November 1866 which gave the ship a maximum speed of . Zealous carried a maximum of of coal. She was ship rigged with three masts and had a sail area of . Her best speed with the propeller disconnected and under sail alone was . Armament All of the available and guns had already been earmarked for other, more powerful ships. Zealous therefore received an armament of guns, which were deemed adequate for her expected service activity, and which, indeed, she retained for the whole of her active career. She was the only battleship ever to have a uniform armament of this calibre,