HMS Devastation ( 1871 ) HMS " Devastation " was the first of two " Devastation " - class mastless turret ship s built for the British 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 . For their first fifteen years , they were the most powerful warships in the world . 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 led to a tendency to mount gun turrets as broadside s . " 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 ( 305 mm ) 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 gun s , 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 5 , 600 horsepower ( indicated ) , 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 by RML 12 - inch 35 ton gun s . 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 6 , 637 horsepower ( indicated ) . 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 . Service history . " Devastation " was deployed to serve in the waters of the United Kingdom and the Mediterranean Sea . In 1891 , the 12 - inch guns were replaced with 10 - inch breech - loading guns and she was refitted with new triple expansion steam engines . In 1901 she was guard ship at the port of Gibraltar . Later , she was refitted again and assigned to the First Reserve Fleet based in Scotland . The ship was broken up in 1908 .