The King George V-class battleships were a group of four dreadnought battleships built for the Royal Navy (RN) in the early 1910s that were sometimes termed super-dreadnoughts. The sister ships spent most of their careers assigned to the 2nd Battle Squadron of the Home and Grand Fleets, sometimes serving as flagships. In October 1914, Audacious struck a mine and sank. Aside from participating in the failed attempt to intercept the German ships that had bombarded Scarborough, Hartlepool and Whitby in late 1914, the Battle of Jutland in May 1916 and the inconclusive action of 19 August, the surviving ships' service during the First World War generally consisted of routine patrols and training in the North Sea.

The three surviving ships were briefly reduced to reserve in 1919 before being transferred to the Mediterranean Fleet in 1920–1921 where they played minor roles in the Allied intervention in the Russian Civil War and the Chanak Crisis of 1922. The first ship to return to Britain, , became a training ship in 1923 but the other two were placed into reserve again upon their return the following year. The imminent completion of the two s in 1927 forced the sale of King George V and for scrap at the end of 1926 while was converted into a target ship to comply with the tonnage limitations of the Washington Naval Treaty.

During the Second World War, Centurion was rearmed with light weapons and was converted into a blockship and was then modified into a decoy with dummy gun turrets. Centurion was sent to the Mediterranean in 1942 to escort a convoy to Malta, although the Italians quickly figured out the deception. The ship was deliberately sunk during the Invasion of Normandy in 1944 to form a breakwater.

Design and description Ordered as part of the 1910–1911 Naval Programme, the King George V class was an enlarged version of the preceding with additional armour, a revised layout of the secondary armament and improved fire-control arrangements.Burt 1986, p. 169; Friedman 2015, pp. 120–121 The ships had an overall length of , a beam of and a draught of . They displaced at normal load and at deep load. Their crew numbered around 869 officers and ratings upon completion and 1,114 in 1916.Burt 1986, p. 176

Sea trials with the battlecruiser showed that the placement of the fore funnel between the forward superstructure and the foremast meant that hot clinkers and flue gases from the boilers made the spotting top on the foremast completely unworkable when the forward boilers were alight and that the upper bridge could easily be rendered uninhabitable, depending on the wind. The King George V class also used the same arrangement and they were altered while under construction to remedy the problem at a cost of approximately £20,000 per ship. The fore funnel was moved aft and a makeshift foremast was built from one of the struts of the original tripod mast. The spotting tower at the rear of the conning tower was removed, the conning tower enlarged, and the coincidence rangefinder was moved from the foremast spotting top to the roof of the conning tower.Brooks 1995, pp. 45, 47–48

The ships of the King George V class were powered by two sets of Parsons direct-drive steam turbines. The outer propeller shafts were coupled to the high-pressure turbines in the outer engine rooms and these exhausted into low-pressure turbines in the centre engine room which drove the inner shafts. The turbines used steam provided by 18 water-tube boilers. They were rated at and were intended to give the battleships a maximum speed of . During their sea trials, the ships exceeded their designed speed and horsepower, reaching a maximum of . They carried a maximum of of coal and an additional of fuel oil that was sprayed on the coal to increase its burn rate. This gave them a range of at a cruising speed of .Burt 1986, pp. 176, 179

Armament

The King George V class was equipped with ten 45-calibre breech-loading (BL) 13.5-inch Mark V gun in five hydraulically powered, centreline, twin-gun turrets, designated 'A', 'B', 'Q', 'X' and 'Y' from front to rear. The guns had a maximum elevation of +20° which gave them a range of . Their gunsights, however, were limited to +15° until super-elevating prisms were installed by 1916 to allow full elevation. In contrast to the Orions, the loading machinery of these turrets was modified to accommodate longer and heavier projectiles, some more than those of the Orions, at a muzzle velocity of about at a rate of two rounds per minute.Friedman 2011, pp. 49–52 The ships carried 100 shells per gun.

Training exercises had shown that destroyer and torpedo boats attacked more frequently from the frontal arc, so the sixteen 50-calibre BL Mark VII guns of the secondary armament was re-arranged to improve fire distribution ahead. Eight of these were mounted in the forward superstructure, four in the aft superstructure, and four in casemates in the side of the hull abreast of the forward main gun turrets, all in single mounts. The guns in the hull casemates were frequently unusable in heavy seas and were later removed during the war. The Mark VII guns had a maximum elevation of +15° which gave them a range of . They fired projectiles at a muzzle velocity of .Friedman 2011, pp. 97–98 They were provided with 150 rounds per gun. Four 3-pounder () saluting guns were also carried. The ships were equipped with three 21-inch submerged torpedo tubes, one on each broadside and another in the stern, for which 14 torpedoes were provided.

Fire-control The ships of the King George V class were some of the first battleships in the RN to receive the full suite of fire-control equipment used during the First World War. The control position for the main armament was located in the conning tower. Data from a coincidence rangefinder (an unstabilized Barr and Stroud instrument in and stabilized Argo units in the other ships) on the roof of the conning tower, together with the target's speed and course information, was input into a Dumaresq mechanical computer and electrically transmitted to a Dreyer Fire-control Table (a Mark III system in King George V and Mark II Tables in the others with an Argo range clock replacing the Dreyer-Elphinstone model in the Mark III) located in the transmitting station located on the main deck. Wind speed and direction was called down to the transmitting station by either voicepipe or sound-powered telephone. The fire-control table integrated all the data and converted it into elevation and deflection data for use by the guns. The target's data was also graphically recorded on a plotting table to assist the gunnery officer in predicting the movement of the target. As a backup, two turrets in each ship could take over if necessary.Brooks 2005, pp. 61–63, 159–160, 166

Fire-control technology advanced quickly during the years immediately preceding World War I, and the development of the director firing system was a major advance. This consisted of a fire-control director mounted high in the ship which electrically provided elevation and training angles to the turrets via pointer on a dial, which the turret crewmen only had to follow. The guns were fired simultaneously, which aided in spotting the shell splashes and minimised the effects of the roll on the dispersion of the shells.Brooks 2005, p. 48 The weight of the director and the enlarged spotting top proved to be more than the unsupported foremast could bear, and it had to be reinforced when the directors were installed in 1913–1914 on the roof of the spotting top. The mast of King George V used flanges, but the other three ships received half-height tripod legs. The former ship's mast was rebuilt into a full-height tripod in 1918. Available sources do not acknowledge that was fitted with a director before her loss, but photographic evidence clearly shows one visible as she was sinking.Brooks 1995, p. 47; Brooks 1996, p. 168

Armour The King George Vs had a waterline belt of Krupp cemented armour that was thick between the fore and rear barbettes. It reduced to outside the central armoured citadel, but did not reach the bow or stern. The belt covered the side of the hull from above the waterline to below it. Above this was a strake of armour. The fore and aft oblique bulkheads connected the waterline and upper armour belts to the 'A' and 'Y' barbettes. The exposed faces of the barbettes were protected by armour 9 to 10 inches thick above the main deck that thinned to below it. The gun turrets had faces sides with 3- to 4-inch roofs. The guns in the forward superstructure were protected by armour thick.Burt 1986, pp. 176–178

The four armoured decks ranged in thickness from with the greater thicknesses outside the central armoured citadel. The front and sides of the conning tower were protected by 11-inch plates, although the roof was 3 inches thick. The gunnery control tower behind and above the conning tower had 4-inch sides and the torpedo-control tower aft had 6-inch sides and a 3-inch roof. Unlike the Orions, the anti-torpedo bulkheads were extended to cover the engine rooms, as well as the magazines with thicknesses ranging from . The boiler uptakes were protected by armour plates.

Modifications By October 1914, a pair of QF anti-aircraft (AA) guns were installed aboard each ship. About of additional deck armour was added after the Battle of Jutland in May 1916 and King George V was fitted to tow kite balloons around the same time. By April 1917, the ships had exchanged a 4-inch AA gun for one of the 3-inch guns and the four 4-inch guns in the hull casemates had been removed. The stern torpedo tube was removed during 1917–1918 and one or two flying-off platforms were fitted aboard each ship in 1918; these were mounted on turret roofs and extended onto the gun barrels. King George V had them on 'B' and 'Q' turrets, Centurion on 'B' and 'X' turrets and Ajax had one on 'B'.Burt, pp. 179–180; Friedman 2015, pp. 198–199, 206

Ships in class + Construction data Name Builder Laid downPreston, p. 30 Launched Completed Cost (including armament) (ex-Royal George)HM Dockyard, Portsmouth16 January 19119 October 191116 November 1912£1,961,096HM Dockyard, Devonport18 November 1911May 1913£1,950,651Scotts Shipbuilding and Engineering Company, Greenock27 February 191121 March 1912March 1913£1,918,813Cammell Laird, Birkenhead23 March 1911Friedman 2015, p. 43814 September 1912August 1913£1,889,387

Careers

While conducting her sea trials on the night of 9/10 December, Centurion accidentally rammed and sank the Italian steamer and she was under repair until March 1913. All four ships of the King George V class were assigned to the 2nd Battle Squadron upon commissioning, commanded by Vice-Admiral Sir George Warrender, and King George V was the squadron flagship by 18 February 1913. Centurion was present to receive the President of France, Raymond Poincaré, at Spithead on 24 June 1913. The sisters represented the Royal Navy during the celebrations of the re-opening of the Kaiser Wilhelm Canal in Kiel, Germany, 23–30 June 1914, held in conjunction with Kiel Week.Burt, pp. 186–188