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The Admiral-class battlecruisers were to have been a class of four British Royal Navy battlecruisers designed near the end of World War I. Their design began as an improved version of the s, but it was recast as a battlecruiser after Admiral John Jellicoe, commander of the Grand Fleet, pointed out that there was no real need for more battleships, but that a number of German battlecruisers had been laid down that were superior to the bulk of the Grand Fleet's battlecruisers and the design was revised to counter these. The class was to have consisted of , ''Anson'', ''Howe'', and ''Rodney'' — all names of famous admirals — but the latter three ships were suspended as the material and labour required to complete them was needed for higher-priority merchantmen and escort vessels. Their designs were updated to incorporate the lessons from the Battle of Jutland, but the Admiralty eventually decided that it was better to begin again with a clean-slate design so they were cancelled in 1919. No more battlecruisers would be built due to the arms limitations agreements of the interbellum. ''Hood'', however, was sufficiently advanced in construction that she was completed in 1920 and immediately became flagship of the Battlecruiser Squadron of the Atlantic Fleet. She served as the flagship of the Special Service Squadron during its round-the-world cruise in 1923-24. ''Hood'' was transferred to the Mediterranean Fleet in 1936 and spent much of the next few years on Non-Intervention Patrols during the Spanish Civil War, returning to the United Kingdom before the beginning of World War II and the Battlecruiser Squadron of the Home Fleet. ''Hood'' spent most of the early part of the war patrolling against German commerce raiders and escorting convoys. Flagship of Force H, based at Gibraltar, she bombarded French ships during the attack on Mers-el-Kébir. In May 1941 Hood and the battleship were ordered to intercept the and the heavy cruiser as they attempted to break out into the North Atlantic. In the subsequent Battle of the Denmark Strait, the aft magazines of the ''Hood'' exploded, sinking her within five minutes of opening fire. ==Design and description== In 1915 the Admiralty was considering the next generation of warship to follow the ''Queen Elizabeth''-class battleships. The Director of Naval Construction (DNC), Sir Eustace Tennyson-d'Eyncourt, was given instructions to prepare designs for a new battleship. The design should: "take the armament, armour and engine power of ''Queen Elizabeth'' as the standard and build around them a hull which should draw as little water as was considered practicable and safe, and which should embody all the latest protection and improvements against underwater attack."〔Raven and Roberts 1976, p. 60〕 The design ('A') was submitted to the Admiralty on 30 November for consideration. The DNC had been able to reduce the draught in comparison to the ''Queen Elizabeth'' by 22% by widening the ship to and lengthening it to ; this had the consequence of restricting the ships to use only one dock in Rosyth and two in Portsmouth. Large anti-torpedo bulges were fitted, and the secondary armament of twelve guns of a new design was mounted on the forecastle deck. The resulting high freeboard gave the design a greater ratio of reserve buoyancy to displacement than in any previous British dreadnought. The design's stretched hull form also gave her an estimated speed of , about faster than the ''Queen Elizabeth'' had been able to reach in service. The First Sea Lord, Admiral Sir Henry Jackson, responded on 6 December that one danger of such a large ship would be start a new arms race with the Americans that Britain could ill-afford, and that better deck protection was necessary to defeat plunging shells during long-range engagements.〔 The Admiralty asked for the design to be reworked ('B') with a maximum beam of , but this was deemed unsatisfactory as it compromised the ship's underwater protection. A pair of revised designs was requested with the speed reduced to to allow the hull to be shortened to better fit in existing floating docks and the minimum possible draught. The first of the two ('C1') was to have full bulge protection and the second ('C2') to have the best bulge protection possible without exceeding ''Queen Elizabeth''s length. 'C1' was shortened by in comparison with 'B' and 'C2' was only in length, but draught increased by . In both proposals it had been necessary to reduce the number of guns in the secondary armament and reduce the thickness of the armour. The Admiralty was not pleased with either design and asked for a revised version of 'A' of the same draught, beam, armour and armament, but shortened and with the same speed as the ''Queen Elizabeth''. In addition the new five-inch gun was rejected in favour of the existing gun.〔Raven and Roberts 1976, p. 61.〕 At least some of the designs were passed to Admiral John Jellicoe, commander of the Grand Fleet, who pointed out that there was no need for new battleships as the British superiority in numbers over the Germans was substantial, but that was not true for battlecruisers. Germany was known to be building three new s with an estimated speed approaching and a reported armament of guns.〔These reports were incorrect; the German ships were designed for and guns. In addition there were four, not three ships in the class. See Campbell, pp. 58–59〕 These ships would be superior to all existing British battlecruisers, and those then under construction (the two and the three 'large light cruisers') were equally fast, but too thinly armoured to compete with them. He also remarked that his experience with the ''Queen Elizabeth''s had persuaded him that an intermediate speed between the battleships and the battlecruisers was of little use; he suggested that the design should be for either a battleship or a thirty-knot battlecruiser, preferably the latter.〔Raven and Roberts 1976, pp. 61–62.〕 The DNC prepared two new designs in response to Admiral Jellicoe's comments on 1 February 1916, each for a battlecruiser capable of thirty knots or better and armed with eight guns. Design '1' displaced with two less inches in belt armour and a speed of thirty knots. It used the bulky large-tube boilers traditional in British capital ships, which explains why the design was larger than any of the previous battleship designs. Design '2' was essentially a repeat of the first design except that small-tube boilers were substituted. These were considerably smaller than the older type and saved over Design '1' and had one less foot of draught.〔Roberts 1997, p. 58.〕 These savings were substantial enough to overcome the Engineer-in-Chief's objections that they required more frequent and expensive repairs.〔Raven and Roberts 1976, p. 70.〕 The DNC was asked to submit four more designs using small-tube boilers which were submitted on 17 February. Design '3' was Design '2' with the machinery power increased to to boost the maximum speed to while the other designs had either four, six or eight guns. Design '3' was selected as Admiral Jellicoe has specified that the minimum number of guns should be no less than eight as fewer caused problems in accurate fire control, and two alternatives were to be provided, one with a dozen 5.5-inch guns and the other with sixteen such guns. The latter proposal was selected on 7 April and orders were placed on 19 April for three ships (''Hood'', ''Howe'' and ''Rodney''). The order for the fourth ship, ''Anson'', was placed on 13 June.〔Roberts 1997, pp. 56–58.〕 was laid down on 31 May 1916, the same day as the Battle of Jutland. The loss of three British battlecruisers during that battle caused the work on all three ships to be suspended pending an investigation into possible design flaws. Admiral Jellicoe's investigation blamed the loss of the ships on faulty cordite handling procedures that allowed fires in the turrets or hoists to reach the ships' magazines. It recommended anti-flash equipment be installed in magazines and handling rooms and the improvement of deck armour over the magazines to prevent plunging shells or fragments from reaching the magazines. The DNC and the Third Sea Lord opposed the latter, believing that there was no direct evidence that the magazines had been directly penetrated.〔Raven and Roberts 1976, p. 63.〕 On 5 July the DNC submitted two revised designs for the Admiral-class ships. The first was a modification of the previous design with slight increases to the deck, turret, barbette, and funnel uptake armour, one-inch protection for the 5.5-inch ammunition hatches and hoists, and the number of electrical generators increased from four to eight. These changes increased the displacement by and draught by . The second design drastically improved the protection and converted the ships into fast battleships. The vertical armour was generally increased by 50% and the deck protection was slightly thickened as in the first design. These changes would have added another to the original design and increased the draught by , but would have cost half a knot in speed. This design would have been equal to the ''Queen Elizabeth''s, but faster and with much improved torpedo protection, although it was some larger than the older ships. After the DNC submitted the above designs, he was asked to consider variations with triple fifteen-inch turrets, and these were submitted on 20 July. The Admiralty chose the fast battleship design, and ''Hood'' was laid down again on 1 September.〔Roberts 1997, pp. 58–60〕 Later that month ''Hood''s armour scheme was slightly revised in light of further analysis of the results of Jutland and the deck armour was modestly increased in order to ensure that a minimum thickness of nine inches of armour would have to be penetrated by shells striking at angles of descent up to 30° from the horizontal. Further alterations were made in 1917 during her construction that increased the thickness of her turret faces and roofs. These changes, plus numerous others, increased her displacement by , her draught by and reduced her speed to . The changes continued during 1918 when the thickness of her magazine crowns was increased from one inch to two; the armour for the funnel uptakes above the forecastle deck was omitted in compensation. In May 1919 her main deck armour at the side abreast the magazines was increased to three inches (76 mm), and four 5.5-inch guns and their ammunition were deleted in consequence. The next month plans were approved to increase the thickness of the main deck over the forward magazines to and to over the rear magazines; her four above water torpedo tubes and their protection were to be omitted and the wall of the torpedo control tower were to be reduced to a thickness of to offset the armour's weight. However, the additional deck armour was never fitted and the torpedo tubes (less their protection) were retained.〔Roberts 1997, pp. 60, 62〕 Earlier in 1917, however, construction of ''Hood''s three sisters had been suspended as the amount of labour and material they required would be better employed in the construction and repair of merchant ships and escorts needed to keep open Britain's lines of communication in the face of the U-boat blockade. Design work continued however, although ''Hood'' was too far advanced to incorporate these changes, and ultimately would have been extensive enough for the other three ships to constitute their own class.〔Campbell 1978, p. 72.〕 At the end of 1917 the suspended ships' design was modified to increase the thickness of the turret roofs to six inches (152 mm), and (unspecified) alterations were made to the armoured bulkheads. These cost a total of in displacement. Other changes were a redesigned bridge structure and moving the funnels closer together and the exchange in position between the fifteen-inch shellrooms and magazines. This latter change would have caused the hull's form to be filled out somewhat to accommodate the handling room of the rearmost turret at the cost of a slight loss in speed and ammunition storage.〔Roberts 1997, pp. 60–61〕 ''Hood'' was the closest to completion and her construction was continued in case the Germans managed to complete any of their new battlecruisers. Admiral Beatty continually pressed to have ''Hood''s construction expedited and for her sisters to be restarted, but the War Cabinet refused to approve either measure as nothing could be sacrificed in the shipbuilding programme to this end. After the end of the war the three suspended ships were cancelled as they could not fully incorporate the lessons of the war.〔Roberts 1997, p. 61.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Admiral-class battlecruiser」の詳細全文を読む スポンサード リンク
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