HMS Devastation was the first of two Devastation-class mastless turret ships built for the Royal Navy. This was the first class of ocean-going capital ship that did not carry sails, and the first whose entire main armament was mounted on top of the hull rather than inside it.
Design and construction
Devastation was built at a time in which steam power was well-established among the world's larger naval powers. However, most ships built at this time were equipped not only with a steam engine, but also with masts and sails for auxiliary power. The presence of masts also prohibited the use of gun turrets since the rigging would obstruct their arc of fire. Devastation, designed by Sir Edward J. Reed, represented a change from this pattern when she was built without masts and her primary armament, two turrets each with two 12-inch muzzle-loading guns, was placed on the top of the hull, allowing each turret a 280-degree arc of fire. Devastation was the first turret ship built to an Admiralty design. She was long between perpendiculars, with a beam of, a mean draught of, and had a freeboard of only. She was armed with four RML 12 inch 25 ton guns, mounted in pairs in two turrets, protected by armour thick. Her breastworks and hull were protected by of armour, and she was also fitted with a spur bow. The ship had a double bottom, and was divided internally into watertight compartments. She was propelled by two four-bladed screws, in diameter, each powered by two direct-acting trunk engines built by John Penn and Sons of Greenwich, providing a total of, with eight boilers, working at, giving a maximum speed of. Devastation could carry 1,350 tons of coal, giving her a range of at 12 knots or at. She also carried 30 tons of water, enough for three weeks, and 19 tons of provisions, six weeks supply for her crew of 329. Following the loss of the masted turret ship, which capsized and sank on 6 September 1870 with the loss of 500 men, almost her entire crew, a special committee was appointed to examine the design of this type of vessel, and particularly the Devastation. Although they found no reason for concern in the stability of the ship, as a safety precaution a number of changes were made to the design. The freeboard was increased to, and armour-plated bulkheads, between thick provided additional protection to the magazines and engines. The 25-ton guns were replaced with RML 12 inch 35 ton guns. This additional weight increased her mean draught to. Sea trials were made in mid-1873 and generated an unusual amount of public interest; not just for the novelty of her appearance, but as the successor to the Captain. In time trials she recorded a speed of, the engines producing. Gunnery trials were made off the Isle of Wight, firing Palliser shells. To judge her behaviour in various sea conditions she was then accompanied by the armoured ships and in a voyage from Plymouth to Castletownbere in southern Ireland, and from there she made two cruises out into the Atlantic. Apart from a tendency for her low forecastle to be swept by the sea, she performed slightly better than her companions in both pitch and roll.
