Engineering Wonders of the World
Volume I

414 ENGINEERING WONDERS OF THE WORLD. shoulder - piece, movable in all directions, and controlling directly the gun itself, which, being accurately balanced, can thus with little exertion of the body be freely moved both horizontally and vertically. The gunner stands at this shoulder-piece, which, is unaffected by the movements of the gun when fired, and casts his eye along the sight. One hand works the elevating gear and training wheel, whilst the other grasps the pistol- shaped trigger. The mounting itself is a central-swung pivot, and, being on live rollers, turns with hardly an effort. The recoil of these lighter guns takes place within the casing, which envelops them like sleeves, and forms the carriage. In the smaller guns of 4-inch calibre, etc., the base of the brass cartridge case used takes the place of the obturator already described, and effectually seals the breech when closed. Of course, advancing to a projectile weighing 100 lbs., with a corresponding increase in the weight of the charge, involved having a brass case of almost unwieldy dimensions. As weight of ammunition is an important consideration in a warship’s equipment, and handicaps rapid handling, the brass case is now dis- pensed with in the 6-inch Q., and the obturator of the larger guns is fitted to their breech-blocks, the shell and charge being placed separately into the breech. When the armoured cruisers of 9,800 tons (known as the “ County ” class, by their being named after British counties) were designed, it was decided to place a Mountings. pair °f ^ch quick-firing guns in a turret forward, and an- other pair aft. The turret for twin-guns, is essentially a British idea, but we had never before built a closed revolving gun-house for a smaller gun than the 9'2-inch. The main objection to this method of mounting light guns is that the rate of fire is reduced some- what, for the clear space about the guns is not great, and does not make for rapidity of service. The turret for the 6-inch guns is 4 inches thick, as is also the barbette in which, it stands. This thickness, too, protects the working chamber beneath the turn-table, in which are situated the electric motor and other parts of the training gear. One hun- dred and thirty-two projectiles are stored, in the barbette for the immediate service of the guns. The charges are brought up the central ammunition tube by an endless band hoist, worked by an electric motor at th© foot of the hoist. This main hoist or lift normally delivers its cartridges to the left, but by an ingenious arrangement of an auxiliary band hoist running at higher speed every alternate cartridge may be delivered to the right. If desirable, projectiles may be placed in the hoist alternately with or in lieu of cartridges. The cartridges and projectiles are loaded into the guns independently by hand. Each gun has a separate sighting position, with handles conveniently placed for working the training switch to the electric training gear, and for elevating by hand. Hand train- ing gear is available if necessary. With electric training the turret can be swung through 360 degrees in 30 seconds, and with the hand gear in 1 minute. The guns can be elevated, loaded, and fired independently, but must, of course, be trained together. The latest development of the 6-inch gun is the 50 calibre weapon produced by Messrs. Vickers Sons and Maxim, the world-famous gun manufacturers and ship- builders. This weapon weighs ^atest n m x ♦ n,« . 1 6-inch Gun. 7 tons 16 cwt., is 310 inches long from muzzle to breech-block, and de- velops a muzzle energy of 7,056 foot-tons. The muzzle velocity is 3,190 foot-seconds, an advance of nearly one-sixth over that of the King Edward VII. guns. The “ tertiary ” or anti-torpedo armament of the King Edward VII. consists of four- teen 12-pounder Q. and a similar number