The St Vincent-class battleships were a group of three dreadnought battleships built for the Royal Navy in the first decade of the 20th century. The sister ships spent their entire careers assigned to the Home and Grand Fleets. Aside from participating in the Battle of Jutland in May 1916 and the inconclusive action of 19 August several months later, their service during the First World War generally consisted of routine patrols and training in the North Sea. was destroyed in 1917 by a magazine explosion with the near total loss of her crew. The remaining pair were obsolete by the end of the war in 1918, and spent their remaining time either in reserve or as training ships before being sold for scrap in the early 1920s.
Vanguards wreck was extensively salvaged before it was declared a war grave. Since 2002, it has been designated as a controlled site under the Protection of Military Remains Act 1986 and diving on the wreck is generally forbidden.
Background and description The Admiralty's 1905 draft building plan called for four capital ships in the 1907–1908 Naval Programme, but the new Liberal government cut one of these ships in mid-1906 and postponed another to the 1908–1909 Naval Programme, pending the conclusion of the ongoing Hague Peace Convention. The failure of the Germans to agree to any sort of naval arms control caused the government to reinstate the third ship. The Admiralty took until 12 June 1907 to decide not to build one of them as a battlecruiser, in favour of a squadron of four homogeneous battleships. Three of these would be part of the St Vincent class, while the single battleship planned for the 1908–1909 Naval Programme was later authorised as .Friedman (2015), pp. 97–102.
The design of the St Vincent class was derived from the preceding , with more powerful guns and a slight increase in size and armour. The ships had an overall length of , a beam of ,Burt (1986), pp. 75–76. and a normal draught of .Preston (1972), p. 125. They displaced at normal load and at deep load. In comparison to the Bellerophon class, the displacement of the St Vincents was increased by , the length by and the beam by ; their crews numbered about 755 officers and ratings upon completion and 835 during the war.Burt (1986), p. 76.
The St Vincent-class ships were powered by two sets of Parsons direct-drive steam turbines, each of which was housed in a separate engine room. The outer propeller shafts were coupled to the high-pressure turbines and these exhausted into low-pressure turbines which drove the inner shafts. Separate cruising turbines were provided for each shaft. The turbines used steam from eighteen water-tube boilers at a working pressure of . They were rated at and were intended to give the ships a maximum speed of . During their sea trials, the St Vincents handily exceeded their designed speed and horsepower, reaching from . They carried 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. 31, 64, 76, 80.
Armament
These ships were the first to carry the new 50-calibre breech-loading (BL) Mark XI gun, which was 5 calibres longer and had a muzzle velocity about higher than the 45-calibre Mark X gun used in the earlier dreadnoughts.Friedman (2011), pp. 59, 62. They had a reputation for drooping at the muzzle, which was believed to have an adverse effect at long range, but testing at sea showed the muzzle droop to be within normal tolerances and the accuracy at long range to be satisfactory.Parkes (1990), pp. 504–05. The increased muzzle velocity of the Mark XI gun gave it a longer range over the Mark X gun as well as increasing the distance at which it could penetrate 12 inches of armour from using the same shell. The higher velocity reduced its service life by increasing the wear in the barrel.Friedman (2011), pp. 59–60, 62–63.
The St Vincent class were equipped with ten Mark XI guns in five hydraulically powered twin-gun turrets, three along the centreline and the remaining two as wing turrets. The centreline turrets were named 'A', 'X' and 'Y' from front to rear, and the port and starboard wing turrets were 'P' and 'Q' respectively. The guns had a maximum elevation of +20° which gave them a range of . They fired projectiles at a muzzle velocity of at a rate of two rounds per minute.Friedman (2011), pp. 62–63. The ships carried between 80 and 100 shells per gun.
The secondary armament of the St Vincents consisted of twenty 50-calibre BL four-inch (102 mm) Mark VII guns. Pairs of these guns were installed in unshielded mounts on the roofs of 'A', 'P', 'Q' and 'Y' turrets and the other dozen were positioned in single mounts at forecastle-deck level in the superstructure.Parkes (1990), p. 503. The guns had a maximum elevation of +15° which gave them a range of firing projectiles at a muzzle velocity of .Friedman (2011), pp. 97–98. They were provided with 150 rounds per gun; the wartime allowance for each gun was 200 rounds. Four 3-pounder saluting guns were also carried. The ships were equipped with three 18-inch (450 mm) submerged torpedo tubes, one on each broadside and another in the stern, for which nine torpedoes were provided.
Fire control
The control positions for the main armament were located in the spotting tops at the head of the fore and mainmasts. Data from a Barr and Stroud coincidence rangefinder located at each control position, together with the target's speed and course information, was input into a Dumaresq mechanical computer and electrically transmitted to Vickers range clocks located in the transmitting station located beneath each position on the main deck. Wind speed and direction was called down to the transmitting station by either voicepipe or sound-powered telephone. The range clock 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. The turrets, transmitting stations and control positions could be connected in almost any combination.Brooks (1995), pp. 40–41. As a backup, two turrets in each ship ('A' and 'Y' in St Vincent) could take over if necessary.Brooks (2005), p. 61.
In 1910–1911, the four-inch guns on the roof of the forward turret of Vanguard were replaced by a rangefinder. This was removed about a year later, roughly at the same time when the rooftop guns were removed from the forward turrets of the other two ships.Burt (1986), pp. 80–81. In late 1914, the remaining rooftop guns were replaced on the three sister ships by 9-foot rangefinders protected by armoured hoods.Admiralty Weekly Order No. 455 of 6 October 1914, referenced in footnotes 16 and 17,
Fire-control technology advanced quickly during the years between the St Vincents' commissioning and the start of World War I and the most important development was the director firing system. Mounted high in the ship, a fire-control director electrically provided data to the turrets via a pointer on a dial, which the turret crewmen only had to follow. The director layer fired the guns 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. While the exact dates of installation are unknown, St Vincent was equipped with a director by December 1915 and the others by May 1916.Brooks (1996), p. 168. The ships were fitted with Mark I Dreyer Fire-control Tables in the transmission stations by early 1916, which combined the functions of the Dumaresq and the range clock.Brooks (2005), pp. 157–158, 175.
Armour The St Vincent-class ships had a waterline belt of Krupp cemented armour that was thick between the fore and aftmost barbettes that reduced to before it reached the ships' ends. It covered the side of the hull from the middle deck down to below the waterline where it thinned to amidships. Above this was a strake of 8-inch armour. Transverse bulkheads thick terminated the thickest parts of the waterline and upper armour belts once they reached the outer portions of the endmost barbettes. The three centreline barbettes were protected by armour thick above the main deck and thinned to below it. The wing barbettes were similar except that they had 10 inches of armour on their outer faces. The gun turrets had faces and sides with 3-inch roofs.Burt (1986), pp. 76, 78.
The three armoured decks ranged in thickness from with the greatest thickness outside the central armoured citadel. The front and sides of the forward conning tower were protected by 11-inch plates, although the rear and roof were 8 inches and 3 inches thick respectively. The aft conning tower had 8-inch sides and a 3-inch roof. The St Vincents had two longitudinal anti-torpedo bulkheads thick that extended from the forward end of 'A' barbette to the end of 'Y' magazine. In the vicinity of the boiler rooms, the compartments between them were used as coal bunkers.Burt (1986), pp. 78, 80.
Modifications
The guns on the forward turret roof were replaced in 1910–1911 by a rangefinder on Vanguard, and on her sisters in 1911–1912. About two years later, gun shields were fitted to most of the guns in the superstructure and the bridge structure was enlarged around the base of the forward tripod mast. During the first year of the war, the base of the forward superstructure was rebuilt to house eight 4-inch guns and the turret-top guns were removed, which reduced their secondary armament to a total of fourteen guns; a pair of 3-inch (76 mm) anti-aircraft (AA) guns were added. Approximately of additional deck armour were added after the Battle of Jutland in May 1916. By April 1917, the sisters mounted thirteen 4-inch anti-torpedo boat guns as well as single 4-inch and 3-inch AA guns. The stern torpedo tube was removed in 1917–1918 and St Vincent was equipped to operate kite balloons. In 1918, a high-angle rangefinder was fitted on the forward spotting top of the surviving ships and flying-off platforms were installed on the roofs of the fore and aft turrets of Collingwood.
Ships + Construction dataShipBuilderPrice (including armament)Laid downLaunchedCommissionedBurt (1986), p. 86.HM Dockyard, Portsmouth£1,721,970 or £1,754,61530 December 190710 September 19083 May 1910HM Dockyard, Devonport£1,680,888 or £1,731,6403 February 19087 November 190819 April 1910Vickers Armstrong, Barrow-in-Furness£1,464,030 or £1,607,7802 April 190822 February 19091 March 1910
Careers Upon commissioning, all three ships were assigned to the 1st Division of the Home Fleet and St Vincent became the flagship of the division's second-in-command. In July, they were present when King George V visited the fleet in Torbay and participated in his Coronation Fleet Review at Spithead on 24 June 1911. Less than a year later, the 1st Division was renamed the 1st Battle Squadron (BS) on 1 May 1912. Collingwood became the squadron flagship on 22 June and reverted to a private ship again two years later. Each of the sisters underwent a lengthy refit before the First World War began in mid-1914.Burt (1986), pp. 86, 88.