Editing Bellerophon-class battleship (section)

==Background and description==
[[File:HMS Bellerophon Broadside.jpg|thumb|left|{{center|Left elevation view from ''[[Jane's Fighting Ships]]'', 1915; darkened areas show armour}}]]
[[File:HMS Bellerophon Plan.jpg|thumb|left|{{center|Left plan view from ''Jane's Fighting Ships'', 1919}}]]
The [[British Admiralty|Admiralty]]'s 1905 draft building plan envisioned four battleships in the 1906–1907 Naval Programme, but the new [[Liberal Party (UK)|Liberal]] government cut one of these ships in mid-1906. The ''Bellerophon''-class design was a slightly larger and improved version of the revolutionary{{refn|''Dreadnought'' was the first battleship with a homogenous main [[Artillery battery|battery]], and was the most powerful and fastest battleship in the world at the time of her completion. She made all other battleships obsolete and gave her name to all the subsequent battleships of her type.<ref>Konstam, pp. 4–5</ref>|group=Note}} preceding {{HMS|Dreadnought|1906|6}}, with better underwater protection and a more powerful [[secondary armament]].<ref>Friedman 2015, pp. 95–97</ref>

The ''Bellerophon''-class ships had an [[length overall|overall length]] of {{convert|526|ft|m|1}}, a [[Beam (nautical)|beam]] of {{convert|82|ft|6|in|m|1}},<ref name=b4/> and a normal [[Draft (hull)|draught]] of {{convert|27|ft|m|1}}.<ref name=p5>Preston 1972, p. 125.</ref> They [[Displacement (ship)|displaced]] {{convert|18596|LT|t|lk=on}} at normal load and {{convert|22211|-|22540|LT|t}} at [[deep load]]. Their crews numbered about 680 officers and [[naval rating|ratings]] upon completion and 840 in 1914.<ref name=b4>Burt, p. 64</ref>

The ''Bellerophon''s were powered by two sets of [[Parsons Marine Steam Turbine Company|Parsons]] [[direct-drive]] [[steam turbine]]s, each of which was housed in a separate [[engine room]]. The outer [[propeller shaft]]s 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 boiler]]s at a working pressure of {{convert|235|psi|kPa kg/cm2|0|abbr=on|lk=on}}. They were rated at {{convert|23000|shp|lk=on}} and were intended to give the ships a maximum speed of {{convert|21|kn|lk=in}}. Refinements to the hull shape allowed the larger ''Bellerophon'' class to match ''Dreadnought''{{'}}s speed despite the same horsepower rating. During their [[sea trial]]s, the ships handily exceeded their designed speed and horsepower. To save weight, they carried slightly less fuel than ''Dreadnought'': {{convert|2648|LT|t|0}} of coal and an additional {{convert|840|LT|t|0}} of [[fuel oil]] that was sprayed on the coal to increase its burn rate. This gave them a range of {{convert|5720|nmi|lk=in}} at a cruising speed of {{convert|10|kn}}.<ref>Burt, pp. 31, 64</ref>

===Armament and armour===
[[File:Bellerophon SP 781.jpg|thumb|''Bellerophon'' firing her main armament]]
In the interest of saving time, the ''Bellerophon''s retained the same main battery and turret layout as ''Dreadnought'':<ref>Friedman 2015, p. 97</ref> ten [[List of British ordnance terms#BL|breech-loading]] (BL) [[BL 12 inch Mk X naval gun|{{convert|12|in|mm|adj=on|sigfig=3}} Mk X guns]] in five twin-[[gun turret]]s, three along the centreline and the remaining pair as [[wing turret]]s. The centreline turrets were designated 'A', 'X' and 'Y', from front to rear, and the [[port and starboard]] wing turrets were 'P' and 'Q' respectively. The guns could initially be depressed to −5° and elevated to +13.5°, although the turrets were modified to allow 16° of elevation during the First World War. They fired {{convert|850|lb|kg|adj=on}} projectiles at a [[muzzle velocity]] of {{convert|2746|ft/s|m/s|abbr=on}}; at +13.5°, this provided a maximum range of {{convert|16500|yd|m|abbr=on}} with [[Armor-piercing shot and shell|armour-piercing (AP)]] 2 [[List of British ordnance terms#C.R.H.|crh]] shells. Using the more aerodynamic, but slightly heavier, 4 crh AP shells at the same elevation, the range was extended to {{convert|18850|yd|m|abbr=on}}. The rate of fire of these guns was about two rounds per minute<ref>Friedman 2011, pp. 59–61</ref> and the ships carried 80 shells per gun.<ref name=b4/>
 
The 12-pounder ({{convert|3|in|mm|adj=on}}) guns with which ''Dreadnought'' was equipped to provide protection from [[torpedo boat]]s were recognised as being insufficiently powerful and sixteen {{convert|4|in|mm|0|adj=on}} guns replaced the twenty-eight guns on ''Dreadnought''. These were 50-calibre [[BL 4 inch naval gun Mk VII|BL 4-inch 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 eight were positioned in single mounts at [[forecastle]]-deck level in the [[superstructure]].<ref name=p3/>{{refn|Sources disagree on the type and composition of the secondary armament. Burt claims that they were the older [[List of British ordnance terms#QF|quick-firing]] QF Mark III guns.<ref name=b4/> Neither book by Preston identify the type, but he does call them quick-firers.<ref name=p5/><ref name=g2/> Parkes also does not identify the type, but he does say that they were 50-calibre guns<ref name=p3>Parkes, p. 498</ref> and Preston agrees.<ref name=g2>Preston 1985, p. 22</ref> Friedman shows the QF Mark III as a 40-calibre gun and states that the 50-calibre BL Mark VII gun armed all of the early dreadnoughts.<ref>Friedman, pp. 97–98</ref>|group=Note}} The guns had a maximum elevation of +15° which gave them a range of {{convert|11400|yd|m|abbr=on|0}}. They fired {{convert|31|lb|kg|adj=on|1}} projectiles at a muzzle velocity of {{convert|2821|ft/s|m/s|abbr=on}}.<ref name=f1>Friedman 2011, pp. 97–98</ref> They were provided with 200 rounds per gun. Four 3-pounder ({{convert|47|mm|in|abbr=on|1|order=flip}}) [[saluting gun]]s were also carried. The ships were equipped with three [[British 18 inch torpedo|18-inch (450&nbsp;mm)]] submerged [[torpedo tube]]s, one on each [[Broadside (naval)|broadside]] and another in the [[stern]], for which fourteen [[torpedo]]es were provided.<ref name=b4/>

In order to accommodate the weight of the enlarged anti-[[torpedo bulkhead]]s, the thickness of the [[Belt armor|waterline belt]] of the ''Bellerophon''-class ships was reduced from {{convert|11|to|10|in|mm|0}} in thickness. The belt consisted of [[Krupp cemented armour]] that extended between 'A' and 'Y' [[barbette]]s, reducing to a thickness of {{convert|6|in|0}} forward and {{convert|5|in|0}} aft before it reached the ships' ends. It covered the side of the [[hull (watercraft)|hull]] from the middle [[deck (ship)|deck]] down to {{convert|5|ft|2|in|m|1}} below the normal [[waterline]] where it tapered to {{convert|8|in|0|}} on the bottom edge. Above this was a [[strake]] of armour 8 inches thick that had its top edge {{convert|8|ft|6|in|m|1}} above the waterline. An 8-inch oblique [[bulkhead (partition)|bulkhead]] connected the thickest parts of the waterline and upper armour belts to the rear barbette; there was no forward equivalent.<ref name=bp>Burt, pp. 62, 64; Parkes, p. 498</ref>

The three centreline barbettes were protected by armour {{convert|9|in|0}} thick above the main [[deck (ship)|deck]] that thinned to {{convert|5|in|0}} below it, except for the rear barbette which was 9 inches thick for its entire height. The wing barbettes were similar except that they had {{convert|10|in|0}} of armour on their outer faces. The gun turrets had {{convert|11|in|0|adj=on}} faces and sides with 3-inch roofs. The three armoured decks ranged in thicknesses from {{convert|0.75|in}} to 4 inches. 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. While ''Dreadnought'' had torpedo bulkheads that protected only the [[Magazine (artillery)|magazines]], the ''Bellerophon''s had complete longitudinal bulkheads, 0.75 to 3 inches thick, that covered the sides of the hull between the fore and aft [[magazine (artillery)|magazine]]s.<ref name=bp/>

===Fire control===
[[File:1913 Canadian $10 bill-obverse.jpg|thumb|The ''Bellerophon'' class on the [[obverse]] of the [[Canadian ten-dollar note|Canadian $10 bill]], 1913]] 
''Dreadnought''{{'}}s [[tripod mast|tripod foremast]] was positioned behind the forward [[funnel (ship)|funnel]] to allow the vertical leg to serve as a support for the boat-handling [[derrick]]. This meant that the hot funnel gases could render the [[Top (sailing ship)|spotting top]] uninhabitable in conditions of little or no wind. The ''Bellerophon''s had the foremast moved forward of the funnels to reduce the problem in the spotting top and a second tripod mast was added to handle the derrick, but it had to be positioned in front of the aft funnel to do that, which rendered the aft spotting top almost useless as it could be exposed to the exhaust plumes from both funnels under certain circumstances.<ref>Brooks 1995, pp. 41–42</ref>

The control positions for the main armament were located in the spotting tops at the head of the fore and [[mainmast]]s. Data from a {{convert|9|ft|m|adj=on|1}} [[Barr and Stroud]] [[coincidence rangefinder]] located at each control position was input into a [[Dumaresq]] mechanical computer and electrically transmitted to [[Vickers range clock]]s located in the transmitting station located beneath each position on the main deck, where it was converted into range and [[Deflection (ballistics)|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.<ref>Brooks 1995, pp. 40–41</ref> As a backup, 'A' and 'Y' turrets in each ship could take over if necessary.<ref>Brooks 2005, p. 61</ref>

An experimental [[fire-control director]] was fitted in the forward spotting top and evaluated in May 1910. This electrically provided data to the turrets via pointers, which the turret crew were to follow. The director layer fired the guns simultaneously which aided in spotting the shell splashes and minimised the effects of the [[ship motions|roll]] on the dispersion of the shells.<ref>Brooks 2005, p. 48</ref> The director was subsequently removed, but ''Superb'' had a production model installed by May 1915 and both ''Temeraire'' and ''Bellerophon'' received theirs by May 1916.<ref>Brooks 1996, p. 168</ref> The latter's director, however, was not fully installed by the date of the Battle of Jutland at the end of the month and she fought without it.<ref name=dread>{{cite web|title=H.M.S. Bellerophon (1907)|url=http://www.dreadnoughtproject.org/tfs/index.php/H.M.S._Bellerophon_(1907)|publisher=The Dreadnought Project|access-date=17 February 2017|language=en}}</ref> Furthermore, they were fitted with Mark I [[Frederic Charles Dreyer#Dreyer Fire Control Table|Dreyer Fire-control Table]]s by early 1916 in the transmission stations. It combined the functions of the Dumaresq and the range clock.<ref>Brooks 2005, pp. 157–158, 175</ref>

===Modifications===
[[File:3 inch AA gun on HMS Bellerophon Scapa Flow WWI IWM Q 68562.jpg|thumb|The 3-inch AA gun on ''Bellerophon''{{'}}s former [[searchlight]] platform, {{Circa|1918}}]]
The guns on the forward turret roof were transferred to the superstructure in 1913–1914 on ''Bellerophon'' and on her sisters in 1914. During the first year of the war, the guns on the wing turrets were moved into the aft part of the superstructure. Sometime around 1915, the guns on the stern turret were removed as were a pair from the superstructure, which reduced their secondary armament to a total of twelve guns. About that time, a pair of 3-inch (76&nbsp;mm) [[anti-aircraft gun|anti-aircraft (AA) guns]] were added. Approximately {{convert|23|LT|t}} of additional deck armour were added after the Battle of Jutland in May 1916. By April 1917, the sisters mounted single 4-inch and 3-inch AA guns and the stern torpedo tube had been removed. One additional 4-inch gun was removed from ''Superb'' in 1917–1918. In 1918, a high-angle [[Rangefinding telemeter|rangefinder]] was fitted on the forward spotting top and [[Flight deck#Early|flying-off platforms]] were installed on the roofs of the fore and aft turrets of ''Bellerophon''. After the war, ''Temeraire'' had four 4-inch guns removed to make space for [[naval cadet]]s and the AA guns were stripped from her and ''Superb''.<ref>Burt, pp. 66, 68–71</ref>