NAVAL GUNS It is convenient to classify naval guns in four categories:— (1) Automatic Guns.—These are small calibre machines guns in which the loading action is entirely performed by the recoil energy. Such guns, of which the 2-pdr. Pom-Pom is typical, are used for anti-aircraft purposes, arming boats and operations on shore.
(2) Semi-automatic Guns.—These are light Q.F. guns in which part of the loading operation may be automatically per formed by the counter-recoil of the gun. These weapons are used where rapid bursts of fire are specially necessary, as in defence against aircraft and destroyer attack. They form the main armament in many destroyers and the anti-aircraft arma ment in battleships and cruisers, in the latter case being mounted in special mountings capable of very high elevation. Guns in this class are generally supplied with fixed ammunition but the use of separate ammunition may be entailed by the confined situation.
(3) Hand-worked Guns.—These are light and medium calibre Q.F. or B.L. guns and form the main armament in some destroy
ers and cruisers and the secondary armament in battleships and large cruisers. A 6 in. projectile weighing Ioo lb. is the heaviest weight which one man can conveniently load by hand ; conse quently, this size of gun is very generally adopted by all nations. The difficulty, however, of hand loading such a gun at high angles of elevation, such as are experienced in anti-aircraft defence, has led to it being mounted in power worked mountings in some warships.
The weight of ammunition which is a consideration of particular importance in small vessels, is less for a B.L. than a Q.F. gun of the same calibre owing to the absence of the metal cartridge case.
(4) Power-worked Guns.—These are heavy guns, above 6 in. calibre, and are generally B.L., but may be Q.F. as in the case of German Krupp guns. They form the primary armament in battleships and large cruisers.