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Rh secondary battery of 14 5-in. guns was fitted a deck higher than in " Pennsylvania " and was unprotected.

The " New Mexico " was distinguished from her sister vessels by the adoption of electric motors for her propulsion, the other two vessels having turbines arranged as previously; she had two turbo- electric generating sets of 11,400 kw. capacity installed, and this electric power was transmitted electrically to four motors of, nomi- nally, 6,600 H.P., one on each of the four propelling shafts. These motors were reversible, thus avoiding, as in the ordinary turbine method of propulsion, the necessity for astern as well as ahead prime movers. The electric drive appears to have been successful, especially as the " New Mexico " was not originally designed for this method of propulsion; the accommodation for the machinery being obtained by modifications in the arrangement of the spaces provided in the original design for turbines, without affecting the other features of the design. The vessel was put through exhaustive trials with satisfactory results, a maximum speed of just over 21 knots being obtained at 31,200 H.P. on a displacement of 32,800 tons, with economical steam and fuel consumption. An advantage con- ferred by the electric drive at cruising ship speeds arises from the ability to obtain the necessary power from only one of the electric generating sets, which can thus be worked at nearly full power and therefore give very good efficiency. The " New Mexico " escorted President Wilson across the Atlantic, and on both eastward and westward voyages only one turbine generating set was used. The weight of the machinery was greater per H.P. than that of turbine machinery of about the same power in British warships, but it was considered that this was capable of improvement in the future, especially in the case of vessels intended from the outset to have the electric drive. The electric drive has been adopted for all suc- ceeding U.S. capital ships.

The " Tennessee " and " California," launched in 1919, were practically repeats of the " New Mexico," the displacement being 32,300 tons. These vessels, however, have two funnels. Also a new system of under-water protection (which has since been adopted for all U.S. battleships) was introduced. This consists of five verti- cal longitudinal bulkheads extending parallel to the ship's side from the forward to the after magazines, thus protecting the whole of the vitals of the ship. The innermost bulkhead is about 17 ft. inboard, the other bulkheads being approximately equidistant from one another; the bulkheads next to the skin bulkhead and innermost bulkhead are all thin plating, the other three being of thicker plating ; the middle three of the five spaces formed by this arrangement are utilized as oil-fuel bunkers.

In Aug. 1915 Congress approved the first building programme ever drawn up for the U.S. navy, according to which 10 battle- ships, 6-battle cruisers, 10 scouts (or light cruisers), 50 destroyers, 9 fleet and 58 coast submarines were to be added in three years to the U.S. navy, in addition to a number of auxiliary vessels.

The first battleships to be built under this programme were the "Colorado" (launched 1921), "Maryland" (launched 1920 and completed 1921), " Washington " and " West Virginia." The dimen- sions of these vessels are not greatly different from the " Tennessee," except that the displacement is slightly greater, being 32,600 tons, the H.P. of the electric propelling machinery being increased to 28,- 900 to maintain the speed of 21 knots. The chief departure in the new vessels was the adoption of 8 i6-in. guns as the primary arma- ment, arranged in four twin-gun turrets superposed in pairs forward and aft. The secondary armament consists of 14 5-in. guns. The armour protection is generally as in the " New Mexico " class.

FIG. 32.

The remaining six battleships of the 1916 programme had not yet been launched in 1921. Their names are " South Dakota," " Indiana," " Montana," " North Carolina," " Iowa," and " Mas- sachusetts " (fig. 32). They are a very great advance on their prede- cessors, being 684 ft. long, 106 ft. wide and displacing 43,200 tons on a draught of 31 feet. An increased speed, 23 knots, is aimed at, the electric drive being of 60,000 horse-power. The main arma- ment is increased by 50%, consisting of 12 i6-in. guns mounted in four triple-gun turrets, and the secondary armament comprises 16 6-in. guns. The torpedo armament was two submerged 2i-in. torpedo tubes throughout all the battleships described in the fore-

going. In 1919 a second three-year programme was considered, to consist of 156 vessels in all, including a further batch of 10 battle- ships and six battle-cruisers.

(2) France. The French navy did not immediately adopt the single-calibre main armament, their first vessels, designed after the " Dreadnought " era had begun, being the " Danton " class, which resembled the " Lord Nelson " in armament, 12 9'4-in. guns being carried in addition to the usual 4 12-in. guns. They were about 2,000 tons heavier than the " Lord Nelson " and were fitted with turbines of 22,500 H.P., giving a speed of 20 knots.

The first French battleships of the " Dreadnought " type were the " Jean Bart " class, launched in 1911 and 1912. These vessels, " Jean Bart," " Paris," " France " and " Courbet," were a consid- erable advance on the " Danton " class, being 546 ft. long, as against 481 ft., with increased beam and draught, and displacement of 23,100 tons. Turbine machinery of 28,000 fl.P. was fitted, giving a speed of 20 knots. The main armament comprised 12 12-in. guns mounted in six twin-gun turrets arranged in two superposed groups forward and aft, with the remaining two turrets on the broadsides amidships. The ahead and astern fire was thus 6 guns and broad- side 10 guns. The secondary armament was very numerous, con- sisting of 22 5-5-in. guns protected by y-in. armour. The side armour was ioj in. thick, tapering to 7 in. at the bow and stern, the turret armour being also lof in. thick.

The " Jean Bart " successfully withstood torpedo attack by an Austrian submarine in 1915, being struck well forward. Compart- ments were flooded, but the vessel proceeded under her own power to Malta, where she was repaired in H.M. Dockyard.

The next battleships built by the French were the " Bretagne " (name ship of the class) (fig. 33), " Lorraine " and " Provence," all launched in 1913, practically repeats of the " Jean Barts," except that the main armament consisted of ip 13'4-in. guns mounted in five twin-gun turrets, all on the centre line of the vessels, the usual superposed groups of two turrets forward and aft, the fifth turret being amidships. The secondary armament again consisted of 22 5'5-in. guns, arranged slightly differently from the " Jean Bart," but this number was decreased after the war to 18, during a partial reconstruction when director-firing was installed on a new tripod foremast.

These vessels were the last battleships completed for the French navy, the completion of the five vessels of the "Normandie" class, launched in 1914 and 1915, having been abandoned, with the exception of the " Beam," which has been converted into an air- craft-carrier. The " Normandie " class were designed to carry 12 13'4-in. in three quadruple-gun turrets, a unique arrangement. The four guns in each turret were arranged on two mountings, so that virtually they comprised two twin guns. The secondary arma- ment was to have consisted of 18 5'5-in. guns. The machinery in- tended for these vessels was of an interesting type, consisting of a combination of turbine and reciprocating engines, the two inner shafts being driven by turbines and the two outer shafts by recipro- cating engines, which alone were powerful enough to have given the vessels a speed of 16 knots, the full power of 35,000 H.P. being designed to give a maximum speed of 21 knots.

It was intended to have laid down in Oct. 1914 four battleships of the " Duquesne " type, but the outbreak of the war caused this intention to be abandoned. The vessels were designed to carry 16 13'4-in. guns in four quadruple-gun turrets, arranged in two super- posed groups forward and aft. The displacement was to have been 29,500 tons, and, with combination turbine and reciprocating engine, a speed of 23 knots was anticipated.

It should be noted that during the whole war period the French Government dockyards, and many private yards also, devoted their whole capacity to the production of munitions of all kinds for the army ; naval work being almost entirely relegated to the background.

No provision was made in the French naval budget for 1921 for the construction of any capital ships.

(3) Japan. The " Satsuma " and " Aki " were the first battle- ships built in Japan after the " Dreadnought " era had begun. They were a development of the " Kashima " class, and therefore