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432 the German ships of similar type, it was deemed advisable to increase the armour protection, if possible. As the result of very extensive investigations, it was found possible, by accepting a deeper draught and a slightly reduced speed, to add very considerably to the pro- tection of the vessel as already designed, without otherwise seriously affecting the design of the ship as a whole. The alterations were of a very radical character, the armour belt being increased from 8 to 12 in. and the barbettes from 9 to 12 in.; and certain increases were also made in the deck protection. At the same time the eight I5-in. gun mountings had their design modified to admit of an ele- vation of 30 degrees, and certain other modifications were made, both in the torpedo armament and also in the arrangements for pre- venting the flash penetrating to the magazines a form of protec- tion which was elaborated for all British ships at this time. All these increases involved an additional weight of nearly 5,000 tons, the legend displacement of the " Hood " becoming finally 41,200 tons when carrying 1,200 tons of fuel; the ship then having a draught of 28J ft., and a draught of 315 ft. with full fuel load, viz. 4,000 tons.

The original length and beam of the ship were maintained as before. Some extra plating had to be provided on the decks for strength purposes, but the under- water protection against torpedoes was retained as in the original design. With the modifications made, the " Hood " when completed was by far the most up-to-date capi- tal ship in existence.

The changes in the design and other circumstances militated against the quick construction of the ship, and it was about four years from the approval of the original design in April 1916 to the time of her completion, this being about double the time taken to build recent British capital ships, and nearly three times that taken to build the " Repulse " and " Renown." The modifications were, however, quite justified by the circumstances, and they made the ship a much more powerfully protected one, whilst increasing her displacement, and consequently the weight of material to be worked, to about 50% more than that of " Repulse " and " Renown."

The main machinery of the " Hood," consisting of geared tur- bines to develop 144,000 H.P., has the largest power which has ever been put through gearing, namely, 36,000 H.P. on each of the four shafts. The machinery is placed in three engine-rooms, of which the forward one contains two independent sets for the outer shafts; the middle and after engine-rooms contain one independent set for each of the inner shafts. This power, which was designed to give 32 knots for the earlier design of 36,300 tons displacement, was expected to give at least 31 knots in deep water with 210 revolutions of the propellers, at a displacement of 41,200 tons for the " Hood " as built. The 24 boilers represented the small-tube type with forced draught, arranged in four boiler-rooms. Such boilers were first adopted for large vessels in the " Courageous " class. Oil is the only fuel used in " Hood." On trials on the measured mile the "Hood" obtained a speed of 32-07 knots with 151,000 S.H.P. at 42,200 tons displacement, and 31-9 knots with 150,000 S.H.P. at 44,600 tons displacement.

It will be seen from the plan (fig. 9) that the main armament of eight 15-in. guns was mounted, as in recent British battleships of the " Queen Elizabeth " and " Royal Sovereign " classes, in four turrets, all on the centre line, with very large arcs of training, the forward ones training to 60 abaft the beam, and the after ones to 60 before the beam. The anti-torpedo-boat destroyer armament consists of twelve 5i-in. guns arranged on the forecastle deck and shelter deck. There are also four 4-in. anti-aircraft guns on the shelter deck aft. There are two 2i-in. submerged torpedo tubes, each in a separate compartment forward, and four 2l-in. above- water torpedo tubes between the upper and forecastle decks; these above-water tubes being a further addition since the original design was made. The distribution of armour is also shown. The 12-in. belt had a length of 562 ft. and a depth of 9 ft. 6 inches. Above the main belt was a strake of J-in. armour to the height of the upp^r deck, and above that again there was 5-in. armour between the upper and forecastle decks. The side armour all sloped outward from below, the shell being thus unable to hit the armour normally, so that the virtual thicknesses were somewhat greater. There was thick plating behind all the armour, varying from 2 in. over the greater portion to ij in. and I in. elsewhere. The torpedo protec- tion consisted of the bulge arrangement, with an outer compart- ment of air and an inner one specially strengthened with the neces- sary separating bulkheads, etc. This protection extended through- put the whole length of the machinery spaces and magazines, and it has been proved that it renders the ship as safe against attack from torpedoes under water as she is against gun attack above water. The oil fuel tanks are arranged along the sides, thus giving addi- tional protection. The " Hood " was successfully launched in Aug. 1918 at Clydebank, the ceremony being performed by Lady Hood, widow of Adml. Hood, who lost his life whilst gallantly leading into action the Third Battle-Cruiser Squadron at Jutland. The launching weight was about 22,000 tons. As the other three ships of the class which were commenced had none of them reached the launching stage at the time of the Armistice, it was subsequently decided not to proceed with them, in view of the international con- ditions, and the " Howe," " Rodney " and " Anson " were accord- ingly scrapped.

As regards the general design of the ship, the " Hood " may be

cited as an example of what can be achieved by going to a large size. Her design embodies the armament and armour protection of a first-class battleship, including also good under-water protect- tion against torpedoes, and at the same time gives the speed of the fastest battle cruisers. This involved great length and displacement. The under-water bulge protection, which has entirely superseded the provision of torpedo netting, is additional to anything pro- vided in pre-war " Dreadnoughts."

In connexion with the size of the " Hood " and general considera- tions of design, it is interesting to note the chief characteristics of the " Queen Elizabeth " and " Renown." The " Queen Eliza- beth " is a well-armoured ship of about 28,000 tons, with eight 15-in. guns and speed of 25 knots, while " Renown," of slightly less dis- placement, viz. 27,000 tons, though of greater length, is a vessel with 7 knots more speed than " Queen Elizabeth," but with only six 15-in. guns against eight, and approximately about half the armour protection provided in the " Queen Elizabeth." The "Hood" has the same armament, viz. eight 15-in. guns, as the " Queen Elizabeth," armour protection fully equal to and, in fact, rather heavier in the aggregate than that of the " Queen Eliza- beth," 7 knots more speed than the " Queen Elizabeth," which makes the speed about equal to that of " Renown," and in addition complete protection against torpedo attack.

FIG. 1 1.

Large Light Cruisers. Early in 1915, as sanction was not given by the British Government for building more capital ships taking two years or longer to complete, while additional light cruisers had been already approved of, it was decided to build " Courageous " and " Glorious ' (figs. II and 12) on the lines of very large light cruisers mounting a few guns of heaviest calibre, so as to be able to annihilate any enemy light cruisers or raiders. They were to have light protection, similar to British light cruisers, and a speed of not less than 32 knots, the draught being restricted to about 22 ft., or about 5 ft. less than any existing battleships or battle cruiser carrying such heavy guns, the main armament of four 15-in. guns in two turrets, one forward and one aft, making them a match for any raider or light cruiser that might be encountered. At this time it should also be remembered that the armaments of ships, especially as regards heavy guns, had to be regulated by the guns and gun mountings which would be available or could be manufactured in a short time, and this condition applied to the 15-in. mountings which were adopted for these ships. The secondary armament consisted of eighteen 4-in. guns in six triple mountings, similar to the triple mountings of the " Renown " and " Repulse." The side arrrour consisted of 2-in. protective plating added to the I-in. shell plating, and a thin protective deck was worked all fore and aft, but this was considerably thickened over the magazines after Jutland. A modi- fied " bulge " was arranged for, as in " Renown " and " Repulse."

The machinery adopted for these ships was of the type fitted in the light cruiser " Champion." It consisted of a 4-shaft arrange- ment of geared turbines, the power being transmitted to the pro- peller shafts by double helical gearing. The eighteen boilers of Yarrow small-tube type were also similar to those of the light cruisers, and with all-oil firing a power of 90,000 S.H.P. at about 340 revolu- tions of propellers was aimed at. Such trials as it was possible to make showed that 32 knots could easily be obtained at the designed displacement, and on service this was actually exceeded.

It was intended that these vessels should be built in a year, or as near that as possible, but this was not realized, and the ships were both commissioned in Oct. 1916.

The " Furious " (see fig. 13), was similar to, but a modification of, the " Courageous " and " Glorious," having about the same length and the same machinery, but the form of midship section was some- what different, having a more pronounced bulge and a simpler form of main framing and structure of the hull. The armament also was different ; each turret, instead of having two 15-in. guns, was arranged to carry one big gun of i8-in. bore.

Early in the spring of 1917 the necessity for having fast aeroplane- carriers became very obvious, and it was approved to fit " Furious " for this purpose. This entailed the removal of the fore turret and making other considerable alterations. A large hangar was built on the forecastle deck, and a flying-off platform 160 ft. long was arranged on the roof of the hangar, which was designed to house about 10 machines. Later it was decided to remove the after-turret as well, and a flying-on deck 300 ft. long, extending from the funnel