6-in. guns. The later battle-cruisers were also armed with the 15-in. gun, the " Renown " class having 6, with a reversion to the 4-in. gun, mounted on triple mountings, as a secondary armament. The Hood," the latest type of battle-cruiser built after the battle of Jutland, mounts 8 15-in. guns with a secondary armament of 16 5'5-in. guns.
In the German navy the earlier battleships and battle-cruisers of the " Dreadnought " era were armed with the il-in. gun, which for many years had been the heaviest gun employed in the German fleet. After 1912 the 12-in. gun became the standard weapon for the capital ships, and remained so until after the battle of Jutland. The secondary armament of all the earlier ships consisted of the 4-i-in. gun, but this was replaced in the later ships by the S-g-in. gun. A Few ships, designed to mount a 15-in. gun, were commenced for the German fleet in 1914, their armament being very similar to that of the British "Queen Elizabeth" class; only 2, the battleships "Baden" and " Bayern," were actually completed, but not until after the battle of Jutland. After the events of 1916, no outstanding developments in naval ordnance occurred in the German navy.
The battle-cruiser has replaced the armoured cruiser of the past, which has consequently disappeared from all modern navies. Similarly the " scout " and " 3rd-class cruiser " type has developed into the modern light cruiser and this latter class has replaced the protected cruiser of the early years of the 2Oth century. The changes that took place in the armament of light cruisers during the war demonstrate the same constant demand for an increased armament as was apparent in the case of the capital ships. The first light cruisers proper, built for the British fleet, were the 6 vessels of the " Active " class, whose armament consisted of 10 4-in. B.L. guns. This class was followed by the larger " Bristol " type in which a pair of 6-in. guns were added. Then followed the 12 ships of the " Chat- ham " and " Birmingham " classes, again larger than their prede- cessors and mounting 8 or 9 6-in. B.L. and no 4-in. guns. The full speed of all these ships had remained constant at about 25 knots, but for tactical reasons smaller and faster ships became necessary. This resulted in the building of the " Arethusa " class, in which the armament was sacrificed to speed, and was reduced to a pair of 6-in. and 6 4-in. guns. These ships entered the fleet at the outbreak of the war in 1914 and were rapidly followed by the 12 " Calliope " class. In these latter ships the upward trend in armament commenced with the addition of a pair of 4.-in. guns on each broadside. War experience soon demonstrated that the 4-in. gun was not powerful enough to inflict severe damage and was completely outranged by the 6-in. gun. Therefore the " Calliope " class were altered to mount 4 6-in. guns in the centre line, all the 4-in. guns being removed. At the same time a third 6-in. gun was added to the armament of the " Arethusa " class in the place of a pair of 4-in. guns. A similar process of rearming light cruisers was carried out simultaneously in the German fleet, by replacing the original 4-in. with 5-g-in. guns. All the light cruisers designed for the British fleet during the war had an armament of 6-in. guns only, mounted on the centre line. In the " Centaur " and " Carlisle ' classes 5 of these guns are carried, and the " D " and " E " classes mount 6 and 7 respectively. The " Hawkins " class forms the extreme development of the light eruiser, for in these ships 7 75-in. B.L. guns are mounted, 6 of which can be fired on either broadside. These vessels are, however, of a special type. They are nearly twice the size of the previous light cruisers, being of about the same tonnage as the old armoured cruisers of the " County " class, though much faster and more powerfully armed. Another special type of ship, classed as light cruisers, were the 3 vessels of the " Courageous " class. These remarkable ships approached the capital ships in displacement, their weapons were of the same class, and they attained a speed of over 30 knots. To obtain this speed the armament and armour protection were reduced. Only two turrets, with 4 is-in. guns, were carried, with a secondary armament of 4-in. guns. 1
In the case of the torpedo-boat destroyers the same gradual increase in gun armament is observable. Until 1910 the 12-pclr. gun was regarded as the heaviest gun that was necessary for a destroyer's armament, but after that date the 4-in. gun began to be used, on account of the increased size of the vessels themselves. At first one or two 4-in. guns were mounted in. combination with the 12-pdr. but finally the 4-in. gun became the sole armament. The" K " and " L " classes, built in 1912-3, and the " M " class of 1914 all carried 3 4-in. guns. The " K" class mounted the 4-in. B.L. Mark VIII. gun and the " L " and " M " classes were armed with the 4-in. Q.F. Mark IV., which became the standard weapon for the many de- stroyers that were built during the first 3 years of the war. In the " V " class the armament consists of 4 4-in. Q.F. Mark V. guns, which are similar to the Mark IV. but more powerful. In the " W " class, which was built in 1918, a further advance was made by mounting 4 A-y-in. B.L. Mark I. guns.
Owing to the avoiding tactics invariably adopted by the Germans, most of the destroyer actions of the war developed into long-range
1 In the first two of the class. The third, the " Furious," was originally designed for 2 i8-in. guns in 2 turrets, but during con- struction was altered to serve as an aircraft-carrier, and the forward turret was removed. Later the after turret was also removed, a secondary armament of 5'5-in. guns only being retained.
combats rather than the short-range milees that had been expected. A number of alterations were therefore made in the armaments of British destroyers, to increase the elevation of the gun-mountings and the range at which the guns could be fought. All British de- stroyers are provided with one anti-aircraft gun. In the smaller vessels the Q.F. 2-pdr. Pom-pom is used for this purpose, but all the more modern destroyers carry a 3-in. H.A. gun on a specially designed mounting. The increase which took place in the armament of destroyers during the war is remarkable. Starting with the " L " class, with the 4-in. Q.F. Mark IV. gun (3i-lb. shell), and a maxi- mum range of 7,900 yd., successive advances have been made to the " W " class, with 4 4>7-in. B.L. Mark I. guns t5o-lb. shell) and a range of 16,000 yd. Thus the weight of the broadside and the maximum range of the armament of the destroyers were more than doubled during the war.
The gun armament of British submarines was not developed on any very definite lines during the war. The submarines were used for attacking the enemy surface craft and submarines upon the high seas, and for scouting duties in the approaches to the enemy ports. For these duties no gun armament, other than a small H.A. gun for defence against aircraft, was usually necessary. In the German navy, on the contrary, guns were mounted in submarines for the specific purpose of attacking merchant ships, and the size of the guns was gradually increased, first from 3-in. to 4-1-111., and finally to 5-9- in. Before the war 12-pdr. guns had been mounted in British sub- marines, chiefly for high-angle fire against aircraft. During the war, guns up to 5'5-in. calibre were mounted in British submarines, in isolated cases for special operations in the Dardanelles, Black Sea and Baltic, but as a general rule the guns carried by these craft were confined to those required for defence against aircraft. When a gun armament is required for a submarine, the 4-in. Q.F. Mark XII., on a special mounting, is the normal gun now employed, in addition to a suitable H.A. armament. Several submarines have been built for the British navy which mount a single 12-in. gun. These vessels may be regarded as submersible monitors rather than true sub- marines, but this proves that it is technically possible to mount guns of practically any calibre in submarines, and undoubtedly the gun armament of future vessels of this type will depend on the develop- ment of the vessels, and the r61e they are designed to fill.
Monitors were a type of vessel that were built for a special pur- pose during the war, and their armament deserves a brief mention. The ships were designed solely for bombarding and for in-shore work. They were of shallow draught and slow speed, and were provided with special protection against damage by torpedoes. The arma- ment consisted, in the larger vessels, of a pair of 12-in., 14-in. or 15- in. guns, 2 supplemented by a small anti-aircraft armament, and subsequently, in some of the ships, by a secondary armament of 6 to 8 6-in. or 4-in. guns. The smaller monitors had a single 9-2 or 7'5-in. gun, or a pair of 6-in. guns, with the addition of a small anti- aircraft armament. The guns and mountings in these ships were usually of an old pattern, alterations being made to allow for high angles of elevation in order to obtain the long ranges required. Special sighting and fire-control arrangements were also fitted to enable the ships to carry out bombardments by indirect fire. All these monitors were built in a very short time, to meet a special set of circumstances brought about by the war. They are a type of vessel not likely to be maintained during peace-time.
During the war a large number of small vessels were fitted out as patrol craft for anti-submarine work, and also for mine-sweeping and mine-laying. The majority of these were commercial craft (such as trawlers, drifters, tugs, etc.) which were converted and armed for their new duties; but a few types of ships came into being, which were specially built for this work. The armament was generally a small one, consisting, at first, of 3 and 6-pdr. guns and afterwards of 12-pdr. and 4-in. guns. At the end of the war a 4-in. gun was mounted in all patrol craft that were capable of carrying so large a gun, and a small anti-aircraft gun was also mounted when possible. Owing to the difficulty of inflicting serious damage on a submarine with a low- trajectory high-velocity gun, howitzers and bombthrowers (see p. 1212) were mounted in many of the vessels employed upon anti- submarine operations.
Heavy Gun Mountings. Recent years have not brought about any very drastic changes in the main principles employed in the design of the turrets in which the heaviest guns are mounted in ships of war. The most recent designs of twin turrets in the British fleet show no very great difference in the general arrangements from those in which the 12-in. guns were mounted in the earlier battle- ships of the " Dreadnought " class. Such changes as have occurred have been caused by the general increase of the weight of the guns and ammunition that now have to be handled by the turret ma- chines. The following description of the arrangement of a 15-in. turret can be taken as typical of modern British turrets for 12-in. guns and above. The salient features in which the turrets of other navies differ from the British are also pointed out.
The universal practice is to carry the moving turret structure inside a fixed circular armoured barbette on a ring of rollers which run upon a roller path built into the structure of the ship. The
2 The i8-in. guns released from the "Furious," as mentioned in footnote I, were mounted under shields on 2 monitors.
