Editing Nelson-class battleship (section)

==Description==
The ''Nelson''s had a [[length between perpendiculars]] of {{convert|660|ft|m|1}} and an [[length overall|overall length]] of {{convert|709|ft|10|in|m|1}} (''Nelson'') or {{convert|710|ft|3|in|m|1}} (''Rodney''), a [[Beam (nautical)|beam]] of {{convert|106|ft|m|1}}, and a [[Draft (hull)|draught]] of {{convert|30|ft|4|in|m|1}} at mean [[Displacement (ship)#Standard displacement|standard load]]. They [[Displacement (ship)|displaced]] {{convert|33300|-|33730|LT|t}} at standard load and {{convert|37430|-|37780|LT|t}} at [[deep load]]. Their crew numbered 1,361 officers and [[naval rating|ratings]] when serving as flagships and 1,314 as [[private ship]]s. At deep load, they had a [[metacentric height]] of {{convert|10.2|ft|m|1}},<ref>Burt, pp. 348–349</ref> which gave them a quick [[Ship motions|roll]] between 11.2 and 13.6 seconds.<ref>Raven & Roberts, pp. 126–127</ref> In calm weather, the ''Nelson''-class ships were very manoeuvrable, but the large surface area of the superstructure gave them a large amount of [[weather helm]] and they could be a handful in confined spaces with a strong wind as was demonstrated when {{HMS|Nelson|28|2}} ran aground off [[Southsea]] beach in 1934.<ref>Burt, pp. 350, 357–359</ref>

The ships were powered by two sets of [[John Brown & Company|Brown-Curtis]] geared [[steam turbine]]s, each driving one shaft, using steam from eight [[Admiralty 3-drum boiler]]s fitted with [[superheater]]s that operated at a pressure of {{convert|250|psi|kPa atm|0|abbr=on|lk=on}}. The turbines were rated at {{convert|45000|shp|lk=on}} and intended to give the ship a maximum speed of {{convert|23|kn|lk=in}}. The [[sister ship]]s exceeded their designed speed during their [[sea trial]]s in 1927, reaching speeds of {{convert|23.6|-|23.8|kn}} from {{convert|45614|-|46031|shp|abbr=on}}. They carried {{convert|3770|-|3805|LT|t}} of [[fuel oil]] to give them a designed range of {{convert|7000|nmi|lk=in}} at a cruising speed of {{convert|16|kn}}.<ref>Raven & Roberts, pp. 114, 124–125</ref>

===Armour===
Armour weight was also reduced by using an internal, inclined armour belt sloped outward at 18 degrees from the vertical. The armour belt was {{convert|14|in|mm|abbr=on}} thick over the main magazines and control positions to {{convert|13|in|mm|abbr=on}} over the machinery and 6-inch gun magazines. The slope increased the relative thickness of the belt to a plunging projectile. Water-filled compartments, surrounded by air-filled ones, formed internal torpedo bulges which were fitted between the armour and the external hull of the ship, which was not armoured. The outer hull plating was meant to initiate detonation of shells which would then explode outside the armour. This innovation dispensed with external torpedo bulges which would otherwise have reduced the speed of the ships due to drag. Underwater protection for the ''Nelson''s was provided by a [[double bottom]] 5 feet (1.5 m) deep and a layered defence of an empty outer [[watertight compartment]] and an inner water-filled compartment. The torpedo defence system had a total depth of 12 feet (3.7 m) and was backed by a [[torpedo bulkhead]] 1.5 inches thick. The system was similar in design and effectiveness to that of ''[[HMS Hood|Hood]]'', and was rated to withstand an explosion of 750 lbs (340 kg) [[TNT]].<ref>{{Cite book|last=Raven|first=Alan|url=https://www.worldcat.org/oclc/2765218|title=British battleships of World War Two : the development and technical history of the Royal Navy's battleships and battlecruisers from 1911 to 1946|date=1976|publisher=Naval Institute Press|others=John, January 16- Roberts|isbn=0-87021-817-4|location=Annapolis|oclc=2765218}}</ref> The armour scheme was of the "[[All or nothing (armour)|all or nothing]]" principle; areas were either well protected, from the front of "A" barbette rearwards to the after 6-inch turrets, or were not protected at all, disposing of the multiple intermediate thickness of armour seen in older designs. For the first time a British battleship had a single, {{convert|6.25|in|mm|abbr=on}} thick armoured deck to protect against plunging shells and aircraft-launched bombs, with {{convert|3.75|in|mm|abbr=on}} armour over the machinery spaces and {{convert|4.25|in|mm|abbr=on}} armour on the lower deck over the stern, both on top of the 0.5 in (12.7&nbsp;mm) deck plating. The main turrets had {{convert|16|in|mm|abbr=on}} armour on the faces, {{convert|11|in|mm|abbr=on}} on the sides, {{convert|7.25|in|mm|abbr=on}} on the roof and {{convert|9|in|mm|abbr=on}} on the rear with {{convert|15|in|mm|abbr=on}} around the barbettes. The secondary turrets, however, had only {{convert|1|in|mm|abbr=on}} NC all round over 0.5 in (12.7&nbsp;mm) structural steel plates.<ref name="ReferenceA"/><ref name="referenceD"/>{{Page needed|date=March 2023}}

===Superstructure===
The large superstructure, which was octagonal in plan, was known to its crew as the "Octopoidal"<ref name="ReferenceC">''HMS Rodney'', Iain Ballantyne, Pen & Sword Books, {{ISBN|978 1 84415 406 7}}</ref>{{Page needed|date=March 2023}} and was sometimes referred to as "[[Queen Anne's Mansions]]"<ref name="ReferenceA">Burt, p.</ref> due to its similarity to a 14-storey brick residential development opposite [[St James's Park tube station]] in London. The superstructure provided spacious, weatherproof working spaces for the navigating officers and any flag officers embarked. Except for the emergency conning tower at its base, and the trunking for the main gun directors mounted on top, the superstructure was lightly armoured against splinters only, to save weight. Additional weight-saving design measures included the use of light materials such as aluminium for fittings, and [[fir]] instead of [[teak]] for deck planking, although subsequently, teak decks were fitted in the late 1920s, following concerns that the ships could not fire a full broadside without causing structural damage to the decks.<ref name="ReferenceA"/>{{Page needed|date=March 2023}}

The ''Nelson'' class was a revolutionary but compromised design, and unsurprisingly there were shortcomings. The location of the superstructure towards the stern caused manoeuvrability problems in high winds, especially when steaming at low speeds, where the superstructure acted somewhat like a [[mizzen]] [[sail]] permanently set, causing the ships to "weathervane" but according to Captain [[Hugh Binney]], who commanded ''Nelson'' in the late twenties, "if this is kept in mind, no real difficulties should be encountered in any circumstances".<ref name="ReferenceA"/>{{Page needed|date=March 2023}} This was potentially a problem in crowded harbours, and made the ships somewhat difficult to dock and embark although this issue never led to a major incident. Binney also stated "In the early stages of the ship's first commission, there was a general misconception that the ''Nelson'' class were unhandy and difficult to manoeuvre. Both my predecessor and myself, however, very soon discovered that this opinion was entirely fallacious! In calm weather, the ship's manoeuvring capabilities are in no way inferior, and in many ways superior to those of ''Queen Elizabeth'' or ''Revenge''."<ref name="ReferenceA"/> They could also be awkward to manoeuvre when moving astern. This was attributed to the ships having a single, central rudder which was out of the propeller race of the twin screws. At sea, however, they were reported to handle well, with a comparatively small tactical diameter (turning circle) particularly when turning into the wind, according to Lt. Commander (later Rear Admiral) [[Galfry Gatacre]] RAN, who served in 1941–1942 as the navigator for both ''Nelson'' and subsequently ''Rodney''. He reported no difficulty in navigating either ship through the boom gates at [[Scapa Flow]].  ''Nelson'' and ''Rodney'' were the only battleships never to have bumped the [[Net laying ship|boom gate vessel]] as they passed through Hoxa Sound.<ref name="ReferenceB">''Reports of Proceedings 1921–1964'', G.G.O. Gatacre, {{ISBN|0 949756 02 4}}</ref>{{Page needed|date=March 2023}}

===Armament===
[[File:HMS Nelson during gunnery trials.jpg|thumb|left|''Nelson'' fires a salvo during gunnery trials in 1942]]
These ships were fitted with the [[HACS]] AA fire control system and the [[Admiralty Fire Control Table]] Mk I for surface fire control of the main armament.

Their main armament of nine {{convert|16|in|mm|0|adj=on}} guns were mounted in triple turrets, the only RN battleships constructed in this manner. The ''[[Lion-class battleship|Lion]]''-class battleships, which were laid down in 1939 but cancelled in 1942, would have also carried nine {{convert|16|in|mm|0|adj=on}} guns in triple turrets. The ''Nelson's'' innovation was an all-forward main armament orientation, in order to maximize the thickness of armor available for a given weight by [[All or nothing (armor)|making the citadel as short as possible]], and this was subsequently copied by the French in the [[Dunkerque-class battleship|''Dunkerque''-class]] and [[Richelieu-class battleship|''Richelieu''-class]] of battleships.<ref name="ReferenceF">''French Battleships 1922–1956'', John Jordan & Robert Dumas, Seaforth Publishing, {{ISBN|978 1 84832 034 5}}</ref>{{Page needed|date=March 2023}} 

The [[BL 16-inch Mk I naval gun]]s themselves deviated from standard British designs. Where previous RN weapons fired heavy shells at a moderate velocity, the ''Nelson''{{'}}s weapons followed the German practice of a lighter shell at a higher velocity. This change in Director of Naval Ordnance policy was due to British testing of surrendered German equipment after World War I, although much later, subsequent testing proved contradictory. Two different rifling rates were tried, and for some time there was a mixture of barrel types in different turrets, even sometimes within the same turret. The guns suffered considerable barrel wear and had a fairly large dispersion pattern, due mainly to the different riflings that each barrel had as they were refurbished over their lifespan. To compensate for barrel wear, muzzle velocities were reduced and a heavier (longer) shell was tried to offset this; but the cost of producing new shells, modifying shell handling and storage equipment came at a time when RN funding had been heavily reduced. The need to reduce displacement led to the use of triple mount turrets, which had early problems with the ammunition handling and loading machinery. The heavier weight of the triple in comparison to a twin turret meant increased stresses on the roller bearings when training the turrets. This was solved by the incorporation of spring-loaded vertical as well as conventional horizontal roller bearings. The triple mount turret proved itself when, in October 1929, a turret crew with two years' experience loaded and fired 33 consecutive rounds without mishap.<ref name="ReferenceA"/> The incorporation of many safety features, achieved with lighter materials, meant that the complex and relatively fragile equipment had to be serviced regularly over the ships' lifetime. Consequently the BL 16-inch Mk I were not generally considered by the RN to be as successful as the previous [[BL 15 inch /42 naval gun|BL 15&nbsp;inch Mark I]]; the [[BL 14-inch Mk VII naval gun|BL 14-inch Mark VII]], fitted to the subsequent [[King George V-class battleship (1939)|''King George V'']]-class battleships, returned to a heavier (relatively) shell and lower velocity, but its performance was compromised by an over-complex quadruple-gun mounting that proved to have reliability defects in combat. 

Firing trials revealed that the blast of 'A' and 'B' turrets on forward bearings caused damage to many weather-deck fittings and conditions on the mess-decks became very uncomfortable. There was a longstanding rumour that the ships could not fire a full broadside without risk of structural damage.[3]{{Citation needed|date=March 2023}}  This was disproved during the action against the German battleship ''Bismarck'', where ''Rodney'' fired upwards of 40 broadsides (380 shells) without major structural damage except to deck planking and upper deck fittings,[11]{{Citation needed|date=March 2023}}  although damage to sickbay fittings, partition bulkheads, toilet bowls and plumbing in the forecastle was extensive. Virtually every light bulb in the forward section was shattered also.[9]{{Citation needed|date=March 2023}} When 'X' turret was fired 30 degrees abaft the beam and elevation of 40 degrees, considerable damage occurred to the two vertically stacked rows of bridge windows.<ref>Raven & Roberts, p. 118</ref> As a result, the guns of "X" turret were usually prohibited from firing abaft of the beam at high elevations during peacetime practice firing. Fitting [[tempered glass]] in the bridge windows was tried, but gun blast still shattered some of them and filled the bridge with flying debris. The design of the Captain's bridge was altered on ''Nelson'' circa 1930–33 to reduce the window area and enclose the upper portion of the previous two rows of glass. A great deal of effort was expended in correcting this problem, and fitting of protective ledges below the new smaller windows proved successful. A new enclosed Admiral's bridge with its requisite reduced windows was built on top of the Captain's bridge and the forward signalling lamps were moved up one level and towards the aft of the bridge. The Admiral's bridge on ''Rodney'' remained stepped back somewhat from the forward edge of the tower, but the Captain's bridge had the same reduced area of glass that ''Nelson'' now had, with larger ledges.<ref name="ReferenceA"/> Blast was also a problem elsewhere; D.K. Brown tells of a test firing that was suspended when DNC observer H.S. Pengelly, who was beneath the foredeck, reported a bright red flash after firing all guns in "A" turret. This was later discovered to be caused by concussion of the observers' eyeballs.<ref name="referenceD"/>{{Page needed|date=March 2023}}

In the final phase of the action against ''Bismarck'', ''Rodney'' fired a pair of 24.5-inch torpedoes from her port-side tube and claimed one hit.<ref>''Reports of Proceedings 1921–1964'', G.G.O. Gatacre, Nautical Press & Publications, Sydney, 1982, {{ISBN|0 949756 02 4}}, pg.140</ref><ref>''On His Majesty's Service, 1940-41'', Joseph H. Wellings, http://www.ibiblio.org/anrs/docs/D/D7/1002wellings_onhismajestysservice.pdf</ref><ref>Ballantyne, p. 142</ref><ref>''Killing the Bismarck'', Iain Ballantyne, Pen & Sword Books, Yorkshire, {{ISBN|978 1 84415 983 3}}, pp. 258–260.</ref> According to [[Ludovic Kennedy]], "if true, [this is] the only instance in history of one battleship torpedoing another".<ref>''Pursuit: The Sinking of the Bismarck'', Ludovic Kennedy, William Collins, {{ISBN|0 00 211739 8}}</ref>{{Page needed|date=March 2023}}  Earlier in this same action the starboard side tube had its sluice door jammed as the result of a near miss from one of ''Bismarck''{{'}}s early salvos. On 27 September 1941, ''Nelson''{{'}}s port torpedo station almost proved to be a liability when an Italian air-launched 18-inch torpedo holed the compartment behind the torpedo body room, allowing 3,750 tons of water to enter the ship. Following this, ''Nelson''{{'}}s torpedo tubes may have been removed<ref>{{cite book | page=14 | year= 1980 | title = Conway's All the World's Fighting Ships 1922–1946 | publisher = Mayflower Books Inc. | location = New York City | isbn =0-8317-0303-2| edition= First American }}</ref> although another source suggests the torpedo tubes were retained in both ships into 1945.<ref>Burt, p. 377</ref>